车辆工程毕业设计外文翻译

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车辆工程毕业设计---英文翻译

车辆工程专业英文翻译原文：The controllable suspension system can improve both ride comfort and handling safety, which has become one research focus in the field of vehicle engineering since1950s.The full-car generally consists of four quarter-car suspension systems(QC)withstrong coupling characteristics,which yield strong coupling effects on vertical,pitch androll movement suspension performances.So far,an effective coordinated control methodfor the full-car with multiple sub-suspension systems has not been proposed.The best ideais to decouple the full-car into four independent QCs1,such that the sophisticated active orsemi-active control scheme for QC suspension can be directly employed,and thus simplifythe complicated controller synthesis for the full-car suspension and improve the real-timeproperty of control system,which has important theoretical and engineering values forrealizing the practical application of controllable suspension.This thesis focuses on the structural decoupling control study of half-car suspension,which has vertical and pitch movements.Firstly,the passive half-car dynamic model isestablished and transferred into the model involving two similar standard QC dynamicmodels.It is found that a coupling damping force exists in the sprung mass,and it can becompensated through adding a damping force in the unsprung mass, in which the half-carsuspension could be decoupled into two independent QCs.Furthermore,a new QCsuspension design with double controllable dampers is proposed on basis of the definedcoupling damping force,in which the traditional passive damper is normally replaced bythe sprung controllable dampe.Another damper named the unsprung controllable damperis installed between the lower control arm and linkage of vehicle controlled by the pitchangular acceleration,which plays role in compensating the yielded coupling damping force.Thus the suspension structural decoupling of half-car can be conveniently achieved and effectiveness of the proposed structural decoupling method of half-car suspension is verified.Finally,three kinds of control manners i.e.,active versus active,semi-activeversus active and semi-active versus semi-active,are fully discussed for the sprung and unsprung controllable dampers,respectively.The proposed active and semi-active slidingmode control schemes for the sprung controllable damper in QC are applied for thedecouplinghalf-car suspension robust control due to the uncertainty of vehicle load,andhe semi-active control manner chooses the semi-active controllable magneto-rheologicaldamper.As a result, the proposed both active versus active and semi-active versus active control manners could achieve the ideal multi-objective suspension performances for thehalf-car,and the proposed structural decoupling control method can be further extended to realize coordinated control of full-vehicle suspension system with multiple sub-suspension.Engineering vehicles working condition is usually relatively poor,coupled with thelimitations of the performance of the vehicle suspension system.It makes these vehicles' driveralways in the vibration of the high strength,and influences the driver's work efficiency,seriously hurts to the driver's spine,and directly leads to the disease.In order to reducevibration to the driver,this thesis usually takes the seat suspension system to isolate vibration,and uses the appropriate control strategies for seat suspension.It can effectively attenuate thevibration caused by uneven ground,reduce the vibration energy passed on to the driver's body,and improve the drivers'ride comfort.Magneto-rheological fluid is a kind of intelligent material,which has good rheologicalproperties.It can be the first choice of the semi-active suspension shock absorber material.According to the characteristics of magneto-rheological fluid,it can be made a lot of productswhich are used in mechanical engineering,civil engineering,etc.The most prominent exampleis magneto-rheological damper for vibration control in cable suspension bridge vibration,high-rise isolation,etc.In addition,the magnetic fluid rheostat vibration application of suspensionsystem is an important domain,including vehicle suspension system and vehicle seatsuspension system.In the suspension of the magneto-rheological damper applications,it ismainly for dissipation produced by the road excitation of vehicle and driver's vibration energy,to improve the ride comfort.Due to its good controllability,wide dynamic range,fast response,low power requirement and comparatively simple structure,magnetorheological(MR)dampers has become one of the focus research projects in automotive semi-active suspension.Besides damping force and dynamic range,the dynamic response is another important parameter of MR dampers,which isa key part of automotive MR semi-active suspension system.The dynamic response is valuable because it is one of the critical factors that determine the practical effectiveness of automotive MR dampers,the applications range of MR dampers and the controlling period directly.In this thesis,the dynamic response of automotive MR dampers is investigated and the effects of various conditions are considered.The main contributions include the following:(1)The properties and applications of MR fluid is reviewed firstly,the importance of the study on MR dampers dynamic response is discussed,and the present situation and existing problems of the study are summarized.Based on the present problems of the study,the main work is put forward.(2)Based on the hydrodynamics theory and working modes of MR dampers,applying the constitutive equations of Newton and Bingham fluid respectively,the parallel plates and annular duct based rheological equations are derived,the calculation approach of damping force is gained,and the theoretical relation between applied current,piston velocity and damping force is determined,which establishes he theoretical basis for the research of MR dampers dynamic response,propose of test approach and design of test system.Based on theoretical analysis of damping force,the calculation model of MR dampers dynamic response is built by analyzing the unstable state of MR fluid between parallel plates.Furthermore, driving by current source,the effect of the connecting way(parallel or serial)of electromagnetic coils is analyzed theoretically.(3)According to the damping force function and practical condition of dampers,an experimental approach for finding the dynamic response of automotive MR dampers and corresponding data processing are offered,the corresponding test system is developed, including some important parts of the test system,such as current driver based on PWM method,and its output characteristic and dynamic response are investigated theoretically and experimentally.译文：可控悬架系统能够同时提高车辆驾乘舒适度与操控安全性,因而具有出色的综合悬架性能,从上世纪五十年代起,就是国际车辆工程领域的研究热点课题之一。

汽车专业毕业设计外文翻译

附录：英汉对照Automotive oxygen sensor failure andinspection of the commonThe automotive industry is currently in the international application of the sensor on one of the largest markets, and the oxygen sensor reported the number of patents, ranking the first in automotive sensors. Oxygen sensor installed in the vehicle exhaust pipe, use it to detect the oxygen content in exhaust port. Oxygen sensor and thus can be obtained in accordance with the signal, put it back to the control system tofine-tune the fuel injection, so that A / F control at best, not only greatly reduces emissions and saves energy. At present, the practical application of the oxygen sensor has zirconia dioxide oxygen sensors and the two oxygen sensors. And common oxygen sensor and a single lead, double-lead and lead of three points; single pin for Zirconia oxygen sensor; double lead for the titanium dioxide oxygen sensor;three-lead type for the heating oxygen zirconia sensors, in principle, lead the way on three of the oxygen sensor is not a substitute for use. Are one of the most widely used type of zirconia oxygen sensor.First, zirconia oxygen sensor structureIn the use of three-way catalytic converters to reduce exhaust pollution on the engine, oxygen sensors are essential components. Oxygen sensor is located in the first section of the exhaust pipe, catalytic converter at the front. There is a Oxygen Sensor zirconia (a ceramic) components manufacturers, all of its outside has a layer ofthin-plated platinum. Zirconia ceramic plated body at one end with a thin layer of platinum closed. Into the protection of the latter was set, and installed in a metal body. Further protect the protection of the role of sets played and sensor can be installed on the exhaust manifold. Ceramic exhaust external exposure, and the internal atmosphere and the environment the same.This component has a very high temperature resistance, low temperature so do not allow current through. However, when high temperature, because of the air and exhaust gas oxygen concentration difference, oxygen ions can, through this component. This raises the potential difference, platinum to enlarge. In this way,air-fuel ratio lower than the theoretical air-fuel ratio (thick), the components in the oxygen sensor in (air) outside (the atmosphere) between the oxygen concentration has a greater bad. Thus, the sensors have a relatively strong one voltage (Johnson V). On the other hand, if the rare gas mixture, air and exhaust gas oxygen concentration difference between the very small, have a sensor, there is only one relatively weak voltage (near 0 volts).Because once the mixture of air-fuel ratio deviation from the theoretical air-fuel ratio, ternary catalysts for CO, HC and NOX purification capacity will be a sharp decline, it is installed at the exhaust pipe oxygen sensor for detecting oxygen concentration in the exhaust, and ECU the issue of feedback signal, and then by theECU to control fuel injection amount of injector change, which will control the mixture at the air-fuel ratio near the theoretical value.Two, automotive oxygen sensor working principleOxygen sensor installed in the exhaust manifold, it can detect the concentration of oxygen in the exhaust, air-fuel ratio calculated, and the results sent to the ECU.For example:1, exhaust gas oxygen concentration in the high –When emissions are significant when the percentage of oxygen, ECU will accordingly determine the air-fuel ratio, and that is very dilute mixture.2, exhaust gas oxygen concentration in the low –When the percentage of oxygen in the exhaust very, ECU to determine air-fuel ratio will accordingly small, that is very strong mixture. Temperature higher than300 ℃, the ceramic materials used for the iron conductor. Under these conditions, if the percentage of oxygen sensors on both sides of the different content will have a voltage change at both ends. Two types of environment (air-side and exhaust side) of the different measurements of the oxygen content of these changes tell ECU, exhaust at the oxygen content in the remainder of the generation of harmful emissions to ensure that combustion is not appropriate percentage. Ceramic materials at temperatures lower than 300 ℃are non-linear, and thus the sensor is not a useful signal transmission. ECU has a special function, that is, heating machine at pm (open-loop operation) to stop the adjustment of the mixture. Sensors equipped with heating elements to reach operating temperature quickly. When current flows through the heating elements, it reduces the iron to make ceramics become conductors of time, and which makes the sensor can be installed in the exhaust pipe of the site later.In the three-way catalytic purifier Medium, ECU using data from the oxygen sensor to regulate the air-fuel ratio, but the method of standard Carburetor EFI device somewhat different.At EFI device, EFI's ECU fuel injection through the increase or decrease from the injected fuel volume, adjusting air-fuel ratio. If the ECU from the oxygen sensor detects the mixture too thick, it will gradually reduce the amount of fuel injection, the mixture of on-thinning. Therefore the actual air-fuel ratio becomes greater than the theoretical air-fuel ratio (more dilute). When this happens, ECU through the oxygen sensor to detect the truth, it will start a gradual increase in the volume of spray. In this way, air-fuel ratio is too low, some will Luan (more dense) until the air-fuel ratio lower than the theoretical. Thus, the cycle repeated, ECU main cloud in this way, constant changes in air-fuel ratio, the actual air-fuel ratio near the theoretical air-fuel ratio.Carburetor in the use of the device, are entered by regulating air intake air-fuel ratio of air-conditioning. Mixture theory is usually air-fuel ratio to maintain a little thick. ECU within the air-fuel ratio oxygen sensor has been the information, and manipulation, according to the actual air-fuel ratio EBCU (electronically controlled intake valve) regulator into the carburetor air intake volume. If mixture is too strong, it allows more air to enter to-thinning: If mixture is too thin, it allows less air to enter,so that moreThird, the common automotive oxygen sensor faultOnce the oxygen sensor fails, the electronic fuel injection system will enable the computer should not be the oxygen concentration in the exhaust pipe of the information, and therefore should not be on the air-fuel ratio feedback control, the engine will increase fuel consumption and exhaust pollution, engine idle speed instability, lack of fire, such as fault-surge situation. Therefore, it is necessary to troubleshoot in a timely manner or replaced.1, oxygen sensor poisoningOxygen sensor poisoning and are often more difficult to control emerging as a fault, in particular, are often the use of leaded petrol cars, even the new oxygen sensor, and can only be the work of thousands of kilometers. If only minor lead poisoning, and then use a box of unleaded petrol, will be able to eliminate the surface of oxygen sensor lead to the resumption of normal work. But often because of excessive exhaust temperature, which lead intrusion in their internal and impede the spread of oxygen ions to oxygen sensor failure can only be replaced at this time.In addition, the oxygen sensor silicon poisoning happened is common. In general, gasoline and lubricants containing silicon compounds generated by combustion silica, silicon rubber seal gasket improper use of silicone emitting gas,will cause the oxygen sensor failure, and therefore want to use good quality fuel and lubricants .Right to choose the repair and installation of rubber gaskets, coated on the sensor not to require the use of factory and other than the anti-solvent, etc.2, carbon depositionNot because of engine combustion, in the carbon deposition formed on the surface of oxygen sensor, oxygen sensor or the internal into the sediment, such as oil or dust will impede or block the external air into the oxygen sensor internal to oxygen sensor signal output inaccurate, ECU should not timely correct air-fuel ratio. Soot produced, mainly for increased fuel consumption, emission levels were significantly increased. At this point, if the sediment removal will restore normal working.3, oxygen sensor ceramic fragmentsCeramic oxygen sensor hardware and crisp, with a hard object by knocking or washing with a strong air currents blowing all its fragmentation and possible failure. Therefore, be particularly careful when handling and found that the timely replacement of problem.4, heater resistance wire blownThe heating-type oxygen sensor, if the resistance heater wire ablation, it is difficult to make sensors to reach normal operating temperature and the loss of role.5, oxygen sensor breaking off the internal circuits.Four, automotive oxygen sensor method1, oxygen sensor heater resistance checkUnplug the oxygen sensor wiring harness plug, use a multimeter resistance measurement file in the oxygen sensor heater terminal access-chu-chu with Ground between access resistance and its resistance to 4-40Ω (refer to specific modelspecification). Such as not meeting the standard, should be the replacement of oxygen sensor.2, oxygen sensor voltage feedback measurementMeasurement of oxygen sensor feedback voltage should unplug the oxygen sensor wiring harness plug, the control circuit models, the feedback from the oxygen sensor voltage output terminal on a thin wire leads, and then plug harness plugs well, in the engine operation , measured from the pinout on the feedback voltage (some models can also be inner socket fault detection by a voltage of oxygen sensor feedback, such as the production of Toyota cars can be a series of fault detection from the socket terminal OX1 or OX2 directly measured oxygen sensor feedback voltage). Oxygen sensor feedback on the test voltage, it is best to use with low-range (typically 2V) and high impedance (resistance greater than 10MΩ) multimeter pointer type. Detection of specific methods are as follows: 1) hot cars engine to normal operating temperature (or after the start-up speed of 2500r/min running 2min); 2) will file a negative voltage multimeter table T then fault detection within the socket or the battery negative electrode E1 is fault detection table T then the socket jack OX1 or OX2, or receive oxygen sensor wiring harness plug on the No. | round; 3) to allow the engine to maintain speed around 2500r/min operation voltage meter at the same time check whether the pointer back and forth between 0-1V swing, with a note of voltage meter pointer 10s the number of swing. Under normal circumstances, with the feedback control, the oxygen sensor feedback voltage will be 0.45V at changing up and down, 10s in the number of feedback voltage changes should not be less than 8 times. If less than 8 times, then oxygen sensor feedback control system or not working properly because the surface of oxygen sensor are possible there is carbon deposition, so that lower sensitivity. In this regard, should be allowed to 2500r/min engine speed operation of about 2min, to clear the surface of the carbon deposition oxygen sensor, and then check the feedback voltage. If the removal of carbon deposition may change after the voltage meter pointer is still slow, then oxygen sensor damaged, or have computer feedback control circuit fault. 4) check whether the damaged oxygen sensor Unplug the oxygen sensor wiring harness plug, so that oxygen sensor is no longer connected with the computer, feedback control system is in a state ofopen-loop control. The multimeter voltage pen table file is directly related to oxygen sensor feedback voltage output terminal connected to the negative form of good Ground pen. Measurement of engine operation at the feedback voltage, the first intake pipe was torn off and then up at the mandatory crankcase ventilation hose vacuum tube or other artificially dilute the mixture to form, at the same time watch voltage meter, the pointer should be dropped readings. Was torn off and then connected to the pipeline, and then unplug the water temperature sensor connector, a 4-8KΩ in place of the resistance temperature sensor, the formation of artificially dense mixture, at the same time watch voltage meter, the indicator reading should be increased. Can also be used, or a sudden release the accelerator pedal down approach to change the concentration of the mixture, in sudden pedal down to accelerate, the mixture变浓, feedback voltage should be increased; sudden release when the accelerator pedal,mixed gas-thinning, feedback voltage should be decreased. If the oxygen sensor feedback voltage without the above changes show that the oxygen sensor has been damaged. In addition, the titanium dioxide-type oxygen sensor using the above method at the time, if a good oxygen sensor output voltage to 2.5V as the center should be up and down fluctuations. Otherwise, the sensor can be removed and exposed to the air, cooling the resistance value after the measurement. If a large resistance value that sensor is ok, or should replace the sensor. 5) oxygen sensor to check the color appearance Removed from the exhaust pipe on oxygen sensors, sensors to check whether the shell to plug up the vents, ceramic core whether or not broken. If damaged, replace the oxygen sensor should be. By observing the top part of the oxygen sensor can also determine the color breakdown:①light gray top: This is the normal color of the oxygen sensor; ②white top: pollution from silicon, oxygen sensor must be replaced at this time; ③brown top: pollution by lead, if serious, we must replace the oxygen sensor; ④black top: caused by carbon deposition, carbon deposition in the exclusion of engine failure, the general oxygen sensor can automatically clear up the accumulatedcarbon. Conclusion: for energy conservation and the prevention of pollution from motor vehicles, most developed countries in the West aerobic sensors installed on my car is loaded oxygen sensor must be used. China's automobile industry with foreign countries, one of the main gap, but also in automotive sensors. Therefore, we can come to promote the use of oxygen sensor is very optimistic about the prospects.汽车氧传感器的常见故障及检查汽车行业是目前在国际上应用传感器最大的市场之一,而氧传感器申报的专利数,居汽车传感器的首位。

车辆工程专业毕业论文_外文翻译

Drive force control of a parallel-series hybrid systemAbstractSince each component of a hybrid system has its own limit of performance, the vehicle power depends on the weakest component. So it is necessary to design the balance of the components. The vehicle must be controlled to operate within the performance range of all the components. We designed the specifications of each component backward from the required drive force. In this paper we describe a control method for the motor torque to avoid damage to the battery, when the battery is at a low state of charge. Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved.1. IntroductionIn recent years, vehicles with internal combustion engines have increasingly played an important role as a means of transportation, and are contributing much to the development of society. However, vehicle emissions contribute to air pollution and possibly even global warming, which require effective countermeasures. Various developments are being made to reduce these emissions, but no further large improvements can be expected from merely improving the current engines and transmissions. Thus, great expectations are being placed on the development of electric, hybrid and natural gas-driven vehicles. Judging from currently applicable technologies, and the currently installed infrastructure of gasoline stations, inspection and service facilities, the hybrid vehicle, driven by the combination of gasoline engine and electric motor, is considered to be one of the most realistic solutions.Generally speaking, hybrid systems are classified as series or parallel systems. At Toyota, we have developed the Toyota Hybrid System (hereinafter referred to as the THS) by combining the advantages of both systems. In this sense the THS could be classified as a parallel-series type of system. Since the THS constantly optimizes engine operation, emissions are cleaner and better fuel economy can be achieved. During braking, Kinetic energy is recovered by the motor, thereby reducing fuel consumption and subsequent CO2 emissions.Emissions and fuel economy are greatly improved by using the THS for the power train system. However, the THS incorporates engine, motor, battery and other components, each of which has its own particular capability. In other words, the driving force must be generated within the limits of each respective component. In particular, since the battery output varies greatly depending on its level of charge, the driving force has to be controlled with this in mind.This report clarifies the performance required of the respective THS components based on the driving force necessary for a vehicle. The method of controlling the driving force, both when the battery has high and low charge, is also described.2. Toyota hybrid system (THS) [1,2]As Fig. 1 shows, the THS is made up of a hybrid transmission, engine and battery.2.1.Hybrid transmissionThe transmission consists of motor, generator, power split device and reduction gear. The power split device is a planetary gear. Sun gear, ring gear and planetary carrier are directly connected to generator, motor and engine, respectively. The ring gear is also connected to the reduction gear. Thus, engine power is split into the generator and the driving wheels. With this type of mechanism, therevolutions of each of the respective axes are related as follows. Here, the gear ratio between the sun gear and theFig. 1. Schematic of Toyota hybrid system (THS).ring gear is ρ:where Ne is the engine speed, Ng the generator speed and Nm the motor speed.Torque transferred to the motor and the generator axes from the engine is obtained as follows:where Te is the engine torque.The drive shaft is connected to the ring gear via a reduction gear. Consequently, motor speed and vehicle speed are proportional. If the reduction gear ratio isη, the axle torque is obtained as follows:where Tm is the motor torque.As shown above, the axle torque is proportional to the total torque of the engine and the motor on the motor axis. Accordingly, we will refer to motor axis torque instead of axle torque.2.2. EngineA gasoline engine having a displacement of 1.5 l specially designed for the THS is adopted [3]. This engine has high expansion ratio cycle, variable valve timing system and other mechanisms in order to improve engine efficiency and realize cleaner emissions. In particular, a large reduction in friction is achieved by setting the maximum speed at 4000 rpm (=Ne max).2.3. BatteryAs sealed nickel metal hydride battery is adopted. The advantages of this type of battery are high power density and long life. this battery achieves more than three times the power density of those developed for conventional electric vehicles [4].3. Required driving force and performanceThe THS offers excellent fuel economy and emissions reduction. But it must have the ability to output enough driving force for a vehicle. This section discusses the running performance required of the vehicle and the essential items required of the respective components.Road conditions such as slopes, speed limits and the required speed to pass other vehicles determine the power performance required by the vehicle. Table 1 indicates the power performance needed in Japan.3.1. Planetary gear ratioρThe planetary gear ratio (ρ) has almost no effect on fuel economy and/or emissions. This is because the required engine power (i.e. engine condition) depends on vehicle speed, driving force and battery condition, and not on the planetary gear ratio. Conversely, it is largely limited by the degree of installability in the vehicle and manufacturing aspects, leaving little room for design. In the currently developed THS, ρ=0.385.3.2. Maximum engine powerSince the battery cannot be used for cruising due to its limited power storage capacity, most driving is reliant on engine power only. Fig. 2 shows the power required by a vehicle equipped with the THS, based on its driving resistance. Accordingly, the power that is required for cruising on a level road at 140 km/h or climbing a 5% slope at 105 km/h will be 32 kW. If the transmission loss is taken into account, the engine requires 40 kW (=Pe max) of power. The THS uses an engine with maximum power of 43 kW in order to get good vehicle performance while maintaining good fuel economy.3.3. Maximum generator torqueAs described in Section 2, the maximum engine speed is 4000 rpm (=Ne max). To attain maximum torque at this speed, maximum engine torque is obtained as follows:From Eq. (3), the maximum torque on the generator axis will be as follows:This is the torque at which the generator can operate without being driven to over speed. Actually, higher torque is required because of acceleration/deceleration of generator speed and dispersion of engine and/or generator torque. By adding 40% torque margin to the generator, the necessary torque is calculated as follows:3.4. Maximum motor torqueFrom Fig. 3, it can be seen that the motor axis needs to have a torque of 304 Nm to acquire the 30% slope climbing performance. This torque merely balances the vehicle on the slope. To obtain enough starting and accelerating performance, it is necessary to have additional torque of about 70 Nm, or about 370 Nm in total.From Eq. (2), the transmitted torque from the engine is obtained as follows:Consequently, a motor torque of 300 Nm (=T m max) is necessary.3.5. Maximum battery powerAs Fig. 2 shows, driving power of 49 kW is needed for climbing on a 5%slope at 130 km/h. Thus, the necessary battery power is obtained by subtracting the engine-generated power from this. As already discussed, if an engine having the minimum required power is installed, it can only provide 32 kW of power, so the required battery power will be 17 kW. If the possible loss that occurs when the battery supplies power to the motor is taken into account, battery power of 20 kW will be needed. Thus, it is necessary to determine the battery capacity by targeting this output on an actual slope. Table 2 lists the required battery specifications.Table 3 summarizes the specifications actually adopted by the THS and the requirements determined by the above discussion. The required items represent an example when minimum engine power is selected. In other words, if the engine is changed, each of the items have to be changed accordingly.4. Driving force controlThe THS requires controls not necessary for conventional or electric vehicles in order to controlthe engine, motor and generator cooperatively. Fig. 4 outlines the control system.Fig. 4. Control diagram of the THS.Inputs of control system are accelerator position, vehicle speed (motor speed), generator speed and available battery power. Outputs are the engine-required power, generator torque and motor torque.First, drive torque demanded by the driver (converted to the motor axis) is calculated from the accelerator position and the vehicle speed. The necessary drive power is calculated from this torque and the motor speed. Required power for the system is the total of the required drive power, the required power to charge the battery and the power loss in the system. If this total required power exceeds the prescribed value, it becomes required engine power. If it is below the prescribed value, the vehicle runs on the battery without using the engine power. Next, the most efficient engine speed for generating engine power is calculated; this is the engine target speed. The target speed for the generator is calculated using Eq. (1) with engine target speed and motor speed. The generator torque is determined by PID control. Engine torque can be calculated in reverse by using Eq. (3) and the torque transferred from the engine to the motor axis can be calculated from (2). The motor torque is obtained by subtracting this torque from the initially calculated drive torque. Since it is not possible to produce a torque whereby the motor consumption power exceeds the total of the generator-generated power and the power supplied by the battery, it is necessary to control the motor power (torque) within this total power. Fig. 5 shows the control method. The sum of the power form the generator and the available battery power become the power that can be used by the motor. The available motor torque can be obtained by dividing this combined power by the motor speed. When the motor speed is low, if the calculated motor torque exceeds the motor specification of torque the motor torque is determined by the specification. By controlling the motor torque requirement with this limited torque, the motor consumption power can be controlled to within the available power. If the available battery power is large enough, the available motor torque hardly limits the motor torque. Conversely, when the charge is low, the motor torque is frequently limited.Fig. 6 shows the respective maximum drive torque of the battery, the engine, and the engine plus the battery while running based on the controls above, when the THS has the components as specified in Section 3.5. ConclusionsThis paper discussed the control of drive power in the Toyota Hybrid System. The following conclusions were obtained:●The performance required for each component can be determined by reversely calculating powerperformance required for a vehicle.●The available battery power varies according to its state of charge. However, by limiting themotor torque, the battery power can be controlled to within the battery's available power.混合动力系统驱动力的串并联控制摘要由于混合动力系统的每个部分都有自己的极限性能，所以汽车动力取决于最脆弱的哪一个组成部分。

车辆工程毕设英文翻译

With the rapid development of automobile industry, there is comfort and vehicle vibration and noise control of more and more stringent requirements. According to relevant data shows that 70 percent of the city noise from the traffic noise, and traffic noise is mainly car noise. It is seriously polluting the urban environment, affecting people's life, work and health. So noise control is not only related to comfort, but also related to environmental protection. However, all also from the vibration noise, vibration can cause certain parts of the early fatigue damage, thereby reducing the service life of motor vehicles; excessive noise can damage hearing the driver will enable the rapid driver fatigue, thus driving security constitutes a grave threat. So noise control, is also related to motor vehicle durability and safety. Thus vibration, noise and comfort are the three closely related, it is necessary to reduce vibration, reduce noise, but also improve ride comfort, and ensure the product economy, vehicle noise control in the standard range.One type of noise arising from car noise are the main factors of air power, mechanical drive, the electromagnetic three parts. From the structure can be divided into the engine (ie, combustion noise), the chassis noise (ie, power train noise, all components connected with the noise), electrical equipment, noise (cooling fan noise, car noise generator), body noise (such as body structure, shape and attachment installation unreasonable noise). One of the engine noise accounted for more than half of motorvehicle noise, including noise and body intake noise (such as engine vibration, the rotational axis Valve, Jin, door switches, such as exhaust noise). Therefore the engine vibration, noise reduction has become a key automotive noise control.In addition, automobile tires at high speed, it will also cause more noise. This is because of the tire at the ground flows, the pattern is located in the air by ground tank and re-extrusion process caused by inhaling gas pump sound, as well as tread patterns with percussive sound of the road.2 noise requirements of regulations in Europe, from October 1996 onwards, the external bus 77dBA noise must be reduced to 74dBA, noise was reduced by half energy, the end of the century further reduced to 71dBA. Japan's laws and regulations, small car in the next decade to control noise standards at the following 76dBA. A number of domestic cities are also planning to traffic trunk lines in 2010 to control noise at the average of less than 70dBA. According to the domestic current data indicate that the domestic value of bus noise permit shall not exceed 82dBA, light trucks for 83.5dBA. This shows that our country in the vehicle noise control will have to make do.3 noise assessment noise evaluation mainly refers to the car, outside noise and vibration adaptive value. Evaluation methods can be divided intosubjective evaluation and objective evaluation. Subjective assessment of the impact of vehicle noise is a major factor in comfort, loudness and uncertainties, such as semantic differential method can be used for subjective evaluation. At an objective evaluation, can be used PCNM noise measuring device for measuring test analysis; addition simulation technology in the finite element method (FEM) and boundary element method (BEM) has been widely applied.4 noise control noise generation and dissemination in accordance with the mechanism of noise control technology can be put into the following three categories: First, the control of noise sources, are two routes of transmission of noise control, noise three recipients are protected. One of the control of noise sources are the most fundamental, the most direct measures, including noise reduction to reduce the exciting force and the engine parts of the exciting force response, which means transformation of acoustic source local oscillator. However, it is difficult to control noise sources when necessary in the route of transmission of noise to take measures, such as sound absorption, sound insulation, noise reduction, vibration and vibration isolation measures. Motor vehicles and vehicle vibration and noise reduction level of power, economy, reliability and strength, stiffness, quality, manufacturing costs and use are closely related.4.1 engine to reduce vibration and noise of the engine noise is the focus of automotive noise control. Engine vibration and noise are generated at source. Engine noise is from fuel combustion, valve bodies, gears and piston timing noise percussion synthesis.(1) ontology engine noiseLower engine noise will be ontological transformation of local oscillator sound sources, including methods such as finite element method analysis and design engines, selection of soft combustion process, improve the structure of the body stiffness, with the use of tight space, reduce noise cylinder cover. For example in the oil pan on an additional stiffener and diaphragm to improve the stiffness of oil pan to reduce vibration and noise. In addition, give the engine Tu damping material is an effective approach. Damping materials can kinetic energy into thermal energy. To deal with the principle of damping is a damping materials and components into its vibrational energy to consume. It has the following structure: Freedom damping layer structure, and spacing of freely damping layer structure, and constrained damping layer structure and spacing of constrained damping layer. It is clear that the adoption of a decrease of resonance amplitude and accelerated the decay of free vibration, reducing the various parts of the Chuan-Zhen capacity, an increase of parts at or above the critical frequency of vibration isolationcapacity.At present, some countries have designed an engine experts active vibration isolation system to reduce engine vibration, in order to achieve the purpose of noise reduction.(2) intake noiseEngine intake noise is one of the main noise source, the Department of the engine noise of air power, with the engine speed increases to strengthen. Non-supercharged engine intake noise major components, including the cyclical pressure fluctuation noise, vortex noise, the cylinder of the Helmholtz resonance noise. Diesel engine supercharger intake noise mainly from the turbocharger compressor. Two stroke engine noise from the Roots pump. In this regard, the most effective method is the use of intake muffler. There is a resistive type muffler (absorption type), resistant muffler (expansion type, resonance type, interference-type and porous decentralized) and the composite muffler. To combine with the air filter (that is in the air filter on an additional resonance chamber and sound-absorbing material, for example, type R3238) has become the most effective intake muffler, muffler volume of more than 20dBA.4.2 Chassis Noise(1) Department of exhaust noiseDepartment of the chassis exhaust noise is the main noise sources, mainly from the exhaust pressure pulsation noise, air flow through the valve seat when issued by eddy current noise, because of boundary layer airflow disturbance caused by noise and exhaust Office jet noise composition. Designed to optimize the performance of a good muffler, to reduce car noise are one of the important means. Optimize design method has acoustic finite element method and acoustic boundary element method, but is still in its infancy. Muffler to avoid the transmission characteristics and vibration characteristics of coupled mufflers are designed to be focused on solving a problem. Secondly, to reduce exhaust noise and improve power is also a pair of contradictions, because to reduce exhaust noise and lower exhaust back pressure on the design of the exhaust pipe has a diameter of conflicting demands, the former requires a smaller diameter, which is opposite . In this regard, the use of parallel flow path of the dual function muffler, at reduced air pressure and reduce noise to be effective. In addition, the engine exhaust manifold to the muffler inlet pipe section, the use of flexible pipe vibration, noise reduction effect can be reduced to about 7dBA.(2) power train noisePowertrain noise from the vibration caused by变速齿轮meshing and rotating shaft vibration. General measures taken are: First, choose low-noise transmission, engine and gearbox are two and the main reducer,such as rear axle and chassis components for flexible rubber pad connections, so as to achieve the purpose of isolation; are three-axis rotational control balance degrees, to reduce torsional vibration.4.3 Electric equipment noise(1) cooling fan noiseCooling fan noise happened devices are subject to wind retaining ring, water pump, radiator and transmission, but the noise generated depends primarily on the chassis.(2) automobile generator noiseAutomotive generator noise depends on the effects of a variety of sources, these sources have magnet source, mechanical and air power source. Noise level depends on the generator magnetic structure and ventilation systems, as well as generators precision manufacturing and assembly.4.4 Body NoiseAs the speed increased, the body will be more and more noise, and air power are the main causes of noise. Therefore, the following programs to improve the body noise: First, to streamline the design of the body, achieve a smooth transition; two are in between the body and framecomponents to adopt a flexible connection; three interior is softened, such as Inner Mongolia at the roof and body skin the use of sound-absorbing material.In addition, the car at high speed when the tire is also a source of noise. Real vehicle Inerting line method has been measured: Tire Tread greater, then the greater the noise. In addition, the tire tread with the noise generated also have a great relationship, there is a reasonable choice of the pattern of steel cord for radial tires to reduce tire noise are an effective way. Materials for the tire, the use of more flexible and soft rubber with high, you can create a low-noise tires.4.5 Other measuresAutomobile noise control, except in the design on the use of optimization methods and optimization of selected components, it can also carry out active control of noise. This is based on sound muffler technology, the principle is: the use of electronic muffler system with the opposite phase of the acoustic noise, vibration so that the two cancel each other out in order to reduce the noise. This muffler device used extremely advanced electronic components, has excellent noise reduction effect can be used to reduce vehicle noise, engine noise, the engine could also be used to proactively support systems, to offset the engine vibration and noise中文翻译：与汽车工业的迅速发展,有舒适和车辆振动和噪声控制的越来越苛刻的要求。

汽车专业--毕业设计外文翻译

英文资料SuspensionSuspension is the term given to the system of springs, shock absorbers and linkages that connects a vehicle to its wheels. Suspension systems serve a dual purpose –contributing to the car's roadholding/handling and braking for good active safety and driving pleasure, and keeping vehicle occupants comfortable and reasonably well isolated from road noise, bumps, and vibrations,etc. These goals are generally at odds, so the tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different.Leaf springs have been around since the early Egyptians.Ancient military engineers used leaf springs in the form of bows to power their siege engines, with little success at first. The use of leaf springs in catapults was later refined and made to work years later. Springs were not only made of metal, a sturdy tree branch could be used as a spring, such as with a bow.Horse drawn vehiclesBy the early 19th century most British horse carriages were equipped with springs; wooden springs in the case of light one-horse vehicles to avoid taxation, and steel springs in larger vehicles. These were made of low-carbon steel and usually took the form of multiple layer leaf springs.[1]The British steel springs were not well suited for use on America's rough roads of the time, and could even cause coaches to collapse if cornered too fast. In the 1820s, the Abbot Downing Company of Concord, New Hampshire developed a system whereby the bodies of stagecoaches were supported on leather straps called "thoroughbraces", which gave a swinging motion instead of the jolting up and down of a spring suspension (the stagecoach itself was sometimes called a "thoroughbrace")AutomobilesAutomobiles were initially developed as self-propelled versions of horse drawn vehicles. However, horse drawn vehicles had been designed for relatively slow speeds and their suspension was not well suited to the higher speeds permitted by the internal combustion engine.In 1903 Mors of Germany first fitted an automobile with shock absorbers. In 1920 Leyland used torsion bars in a suspension system. In 1922 independent front suspension was pioneered on the Lancia Lambda and became more common in mass market cars from 1932.[2]Important propertiesSpring rateThe spring rate (or suspension rate) is a component in setting the vehicle's ride height or its location in the suspension stroke. Vehicles which carry heavy loads will often have heavier springs to compensate for the additional weight that would otherwise collapse a vehicle to the bottom of its travel (stroke). Heavier springs are also used in performance applications where the loading conditions experienced are more extreme. Springs that are too hard or too soft cause the suspension to become ineffective because they fail to properly isolate the vehicle from the road. Vehicles that commonly experience suspension loads heavier than normal have heavy or hard springs with a spring rate close to the upper limit for that vehicle's weight. This allows the vehicle to perform properly under a heavy load when control is limited by the inertia of the load. Riding in an empty truck used for carrying loads can be uncomfortable for passengers because of its high spring rate relative to the weight of the vehicle. A race car would also be described as having heavy springs and would also be uncomfortably bumpy. However, even though we say they both have heavy springs, the actual spring rates for a 2000 lb race car and a 10,000 lb truck are very different. A luxury car, taxi, or passenger bus would be described as having soft springs. Vehicles with worn out or damaged springs ride lower to the ground which reduces the overall amount of compression available to the suspension and increases the amount of body lean. Performance vehicles can sometimes have spring rate requirements other than vehicle weight and load.Mathematics of the spring rateSpring rate is a ratio used to measure how resistant a spring is to being compressed or expanded during the spring's deflection. The magnitude of the spring force increases as deflection increases according to Hooke's Law. Briefly, this can be stated aswhereF is the force the spring exertsk is the spring rate of the spring.x is the displacement from equilibrium length i.e. the length at which the spring is neither compressed or stretched.Spring rate is confined to a narrow interval by the weight of the vehicle,load the vehicle will carry, and to a lesser extent by suspension geometry and performance desires.Spring rates typically have units of N/mm (or lbf/in). An example of a linear spring rate is 500 lbf/in. For every inch the spring is compressed, it exerts 500 lbf. Anon-linear spring rate is one for which the relation between the spring's compression and the force exerted cannot be fitted adequately to a linear model. For example, the first inch exerts 500 lbf force, the second inch exerts an additional 550 lbf (for a total of 1050 lbf), the third inch exerts another 600 lbf (for a total of 1650 lbf). In contrast a 500 lbf/in linear spring compressed to 3 inches will only exert 1500 lbf.The spring rate of a coil spring may be calculated by a simple algebraic equation or it may be measured in a spring testing machine. The spring constant k can be calculated as follows:where d is the wire diameter, G is the spring's shear modulus (e.g., about 12,000,000 lbf/in² or 80 GPa for steel), and N is the number of wraps and D is the diameter of the coil.Wheel rateWheel rate is the effective spring rate when measured at the wheel. This is as opposed to simply measuring the spring rate alone.Wheel rate is usually equal to or considerably less than the spring rate. Commonly, springs are mounted on control arms, swing arms or some other pivoting suspension member. Consider the example above where the spring rate was calculated to be500 lbs/inch, if you were to move the wheel 1 inch (without moving the car), the spring more than likely compresses a smaller amount. Lets assume the spring moved 0.75 inches, the lever arm ratio would be 0.75 to 1. The wheel rate is calculated by taking the square of the ratio (0.5625) times the spring rate. Squaring the ratio is because the ratio has two effects on the wheel rate. The ratio applies to both the force and distance traveled.Wheel rate on independent suspension is fairly straight-forward. However, special consideration must be taken with some non-independent suspension designs. Take the case of the straight axle. When viewed from the front or rear, the wheel rate can be measured by the means above. Yet because the wheels are not independent, when viewed from the side under acceleration or braking the pivot point is at infinity (because both wheels have moved) and the spring is directly inline with the wheel contact patch. The result is often that the effective wheel rate under cornering is different from what it is under acceleration and braking. This variation in wheel rate may be minimized by locating the spring as close to the wheel as possible.Roll couple percentageRoll couple percentage is the effective wheel rates, in roll, of each axle of the vehicle just as a ratio of the vehicle's total roll rate. Roll Couple Percentage is critical in accurately balancing the handling of a vehicle. It is commonly adjusted through the use of anti-roll bars, but can also be changed through the use of different springs.A vehicle with a roll couple percentage of 70% will transfer 70% of its sprung weight transfer at the front of the vehicle during cornering. This is also commonly known as "Total Lateral Load Transfer Distribution" or "TLLTD".Weight transferWeight transfer during cornering, acceleration or braking is usually calculated per individual wheel and compared with the static weights for the same wheels.The total amount of weight transfer is only affected by 4 factors: the distance between wheel centers (wheelbase in the case of braking, or track width in the case of cornering) the height of the center of gravity, the mass of the vehicle, and the amount of acceleration experienced.The speed at which weight transfer occurs as well as through which components it transfers is complex and is determined by many factors including but not limited to roll center height, spring and damper rates, anti-roll bar stiffness and the kinematic design of the suspension links.Unsprung weight transferUnsprung weight transfer is calculated based on the weight of the vehicle's components that are not supported by the springs. This includes tires, wheels, brakes, spindles, half the control arm's weight and other components. These components are then (for calculation purposes) assumed to be connected to a vehicle with zero sprung weight. They are then put through the same dynamic loads. The weight transfer for cornering in the front would be equal to the total unsprung front weight times theG-Force times the front unsprung center of gravity height divided by the front track width. The same is true for the rear.Suspension typeDependent suspensions include:∙Satchell link∙Panhard rod∙Watt's linkage∙WOBLink∙Mumford linkage∙Live axle∙Twist beam∙Beam axle∙leaf springs used for location (transverse or longitudinal)The variety of independent systems is greater and includes:∙Swing axle∙Sliding pillar∙MacPherson strut/Chapman strut∙Upper and lower A-arm (double wishbone)∙multi-link suspension∙semi-trailing arm suspension∙swinging arm∙leaf springsArmoured fighting vehicle suspensionMilitary AFVs, including tanks, have specialized suspension requirements. They can weigh more than seventy tons and are required to move at high speed over very rough ground. Their suspension components must be protected from land mines and antitank weapons. Tracked AFVs can have as many as nine road wheels on each side. Many wheeled AFVs have six or eight wheels, to help them ride over rough and soft ground. The earliest tanks of the Great War had fixed suspensions—with no movement whatsoever. This unsatisfactory situation was improved with leaf spring suspensions adopted from agricultural machinery, but even these had very limited travel. Speeds increased due to more powerful engines, and the quality of ride had to be improved. In the 1930s, the Christie suspension was developed, which allowed the use of coil springs inside a vehicle's armoured hull, by redirecting the direction of travel using a bell crank. Horstmann suspension was a variation which used a combination of bell crank and exterior coil springs, in use from the 1930s to the 1990s.By the Second World War the other common type was torsion-bar suspension, getting spring force from twisting bars inside the hull—this had less travel than the Christie type, but was significantly more compact, allowing the installation of larger turret rings and heavier main armament. The torsion-bar suspension, sometimes including shock absorbers, has been the dominant heavy armored vehicle suspension since the Second World War.中文翻译悬吊系统(亦称悬挂系统或悬载系统)是描述一种由弹簧、减震筒和连杆所构成的车用系统，用于连接车辆与其车轮。

车辆工程毕业论文英文版

车辆工程毕业论文英文版Title: An Overview of Vehicle EngineeringAbstract:This paper provides an overview of vehicle engineering as a field of study and research. It highlights the significance of vehicle engineering in the automotive industry and its role in designing, developing, and manufacturing vehicles. The paper discusses various aspects of vehicle engineering, including vehicle dynamics, powertrain systems, chassis design, and safety features. Additionally, it explores the future trends and challenges in the field.1. Introduction:Vehicle engineering is a multidisciplinary field that encompasses various aspects of mechanical engineering, electrical engineering, and automotive technology. It involves the design, development, and manufacturing of automobiles, with a focus on optimizing their performance, safety, efficiency, and sustainability.2. Vehicle Dynamics:One of the key areas of vehicle engineering is vehicle dynamics, which deals with the study of forces andmotions affecting a vehicle's behavior. Factors such as acceleration, braking, steering, and handling characteristics are analyzed to ensure optimal driving performance and safety. Vehicle dynamics also play a crucial role in the development of advanced driver-assistance systems and autonomous vehicles.3. Powertrain Systems:Another significant aspect of vehicle engineering is powertrain systems, which consist of the engine, transmission, and drivetrain components. The efficiency, reliability, and performance of these systems greatly impact the overall vehicle performance. Advancements in powertrain technologies, such as hybrid and electric propulsion systems, are crucial for achieving increased fuel efficiency and reduced emissions.4. Chassis Design:Chassis design focuses on the structural framework of the vehicle and its components, including suspension, steering, and braking systems. It plays a critical role in ensuring vehicle stability, ride comfort, and handling. The use of innovative materials and advanced manufacturing techniques has led to lighter and stronger chassis designs, improving fuel efficiency and overall vehicle performance.5. Safety Features:Vehicle engineering also involves the integration of various safety features to protect occupants and pedestrians. These include anti-lock braking systems, electronic stability control, airbags, and collision avoidance systems. The development and implementation of advanced safety technologies aim to reduce the likelihood and severity of accidents, improving overall road safety.6. Future Trends and Challenges:The field of vehicle engineering is constantly evolving, driven by advances in technology and changing market demands. Future trends include the development of autonomous vehicles, electric and hydrogen fuel technologies, and the integration of artificial intelligence in vehicle systems. However, along with these advancements come challenges such as improving battery technology, addressing cybersecurity concerns, and adapting existing infrastructure for advanced technologies.Conclusion:Vehicle engineering is a crucial field within the automotive industry, encompassing various disciplines and aspects of vehicle design, development, and manufacturing. The optimization of performance, safety,efficiency, and sustainability remains the key focus for vehicle engineers. Advancements in vehicle dynamics, powertrain systems, chassis design, and safety features contribute to the continuous improvement of automobiles. Looking ahead, the field continues to face new opportunities and challenges as technologies and market demands evolve.。

汽车专业毕业论文翻译中英文（全）AUTOMOBILE

Mark Steffka, B.S.E., M.S., is with the Electromagnetic Compatibility (EMC) Engineering Group of General Motors (GM) Pow ertrain and is a faculty member of two universities in the Detroit, Michigan, area. He has over 25 years of industry experience in the design, development, and testing of military, aerospace and automotive electronics, including power, control, and radio frequency (RF) systems. Since 2000, he has been an adjunct lecturer at the University of Michigan-Dearborn, in the Electrical and Computer Engineering (ECE) department for the undergraduate and graduate classes on EMC, and was a Co-Principal Investigator for a United States’ National Science Foundation grant which resulted in the establishment of the campus’ EMC laboratory. For the college’s Engineering Professional Development office he is the instructor for engineering continuing education courses on “Automotive EMC” and “Antennas”. He is the recipient of faculty and alumni awards from the University of Michigan – Dearborn, College of Engineering and Computer Science, for his contributions to engineering education and the EMC curriculum. At the University of Detroit –Mercy he is an adjunct professor and teaches an undergraduate and graduate engineering course on EMC. He is a member of Institute of Electrical and Electronics Engineers(IEEE), has served as a session chair for the IEEE EMC Symposium and a technical session organizer for the Society of Automotive Engineers (SAE) World Congress. He has been a speaker at IEEE and SAE conferences held in the United States and international locations.His publications have covered topics on EMC, RFI, and was a co-author of the book“Automotive Electromagnetic Compatibility”. He has held an amateur radio license since 1975, with the call sign WW8MS, is a Life Member of ARRL, the National Association for Amateur Radio, and serves on the ARRL EMC Committee.马克Steffka，疯牛病，硕士，是与电磁兼容性（EMC）工程集团，通用汽车（GM）的动力，是两个在密歇根州底特律地区的大学任教。

汽车专业毕业设计翻译中英文(全)competition and regulation in the korean automobile insurance indu

05/31/07Competition and Regulation in the Korean Automobile Insurance IndustryWondon Lee*Soga Ewedemi*** Associate Professor of Insurance, Daegu University, South Koreawlee@daegu.ac.kr** Professor of Finance, Clarion University of Pennsylvania, U.S.Aewedemi@1. IntroductionThe Korean property and liability insurance industry had assets of US$49 billion and direct premiums written of US$25 billion in 2005, which was the second largest market in Asia and 10th in the world (Swiss Re, 2006). Automobile insurance accounted for 35.2% of the total premiums written, which is the important business line in the Korean property and liability insurance industry.1Since the monopolized market was opened to all the property and liability insurance companies in 1983,2the average growth rate of direct premium is over 18%. This rapid growth rate is attributed mainly to the dramatic increase in automobile usage and compulsory automobile liability insurance.3However, automobile insurance has not been a profitable business since the advent of competition in the market in 1983. During 23 fiscal years including year 2005 the automobile insurance industry experienced underwriting profits only two times in 1997 and 1998. Although underwriting losses have been totally or partially offset by investment profits, the industry has been believed to experience chronic operating losses.4The huge aggregate losses have been based on complaints about a strict government regulation and demands for changes and improvements in the regulation, including increases in premium (the price of insurance). In fact the history of the Korean automobile insurance industry is the history of deregulation on the industry. However, in spite of the series of deregulation the situation has not been much improved.The continual unsatisfactory performance could be ascribed to the more fundamental problems in this industry. Unfortunately it is hard to find more thorough study and analysis to find the fundamental problems about the automobile insurance industry in Korea. In this paper, we extensively examine the Korean automobile insurance industry in the context of the1In 2005Korean property-liability insurance statistics shows that the share of direct premium of long-term insurance is 47.9%. However, long-term insurance is simply a product in which an assumed interest rate is used for rate-making and of which insurance period is usually greater than or equal to 3 years. Long-term insurance products have been usually developed for accidental and sickness insurance, general property insurance, and even individual annuity. Due to large premium income in nature long-term insurance has grown up rapidly since its advent in 1969. That is the reason why a portion of direct premium from automobile insurance is quite less than around 50% unlike other countries with the fully developed property-liability insurance industry.2Although some property and liability insurance companies were licensed to sell automobile insurance after the Korean War (1950-1953), there was no actual business due to a lack of experience and uncertainty about its profitability. In 1957 the growing social concern about protecting persons injured by automobile accidents led to establish Korea Automobile Insurance Company operated by the National Automobile Transportation Association. After 4 year operation the company went bankruptcy due to mismanagement. Right after that, in 1962, a new Korea Automobile Insurance Company was established in the form of an insurance pool by 10 property and liability insurance companies. The company was converted to a stock company in 1968. Since 1962, the Korean automobile insurance industry has been monopolized by one company under a strict government control until the industry was opened to 13 property and liability insurance companies including 2 foreign companies in 1983.3Compulsory automobile liability insurance for bodily injury began in 1963 and also liability for property damage was mandated in 2004.4The Korean property-liability insurance companies do not disclose investment profits attributable to the fund from the automobile insurance sector since they do not have separate investment accounts according to the business lines.structure-conduct-performance (S-C-P) framework of industrial organization.5We also analyze the regulatory environment in which this industry operates and the possible effects of regulation and deregulation on industry performance as well as on industry structure and conduct.The study begins with an analysis of the structure of the automobile insurance industry with a brief history. This chapter deals with market concentration, entry barriers, and economies of scale as well as production. The third chapter examines the pricing behavior of the industry under the tariff system imposed by the government and the price liberalization starting in 1994. The effects of antitrust law against a cartel-like pricing behavior are presented. Chapter 4 examines the performance of the automobile insurance industry in the context of profitability of business and affordability and availability of insurance coverage.In the final chapter, some policy implications are proposed based on the analyses and concluding remarks follow.2. The structure of the automobile insurance industryBrief historyIn Korea a true automobile insurance business has begun with the establishment of Korea Automobile Insurance Company (KAIC) in 1962, which was funded by 10 incumbent property and liability insurance companies. Before 1962 Korean property and liability insurance companies’ operation had been confined mainly to fire and marine insurance, even though they had licenses to sell automobile insurance. They thought automobile insurance was very risky and unprofitable business since the market was very small with about 30,000 cars in the country and there was no accumulated data for rate-making.However, growing public concerns about automobile accident victims forced property and liability insurance companies to make an insurance pool to provide automobile insurance coverage on a voluntary basis. The outcome was an insurance pool, so called KAIC, which was converted to a stock company in 1968. In 1963 following year of the establishment, bodily injury liability with a policy limit became compulsory by the law. Since 1963, with rising automobile usage, the automobile insurance has become increasingly important in Korean property and liability insurance industry. Till 1997, when the long-term insurance overtook, the automobile insurance had been the largest part of the Korean property and liability insurance industry. <Figure 1> shows the premium distribution by lines of property and liability insurance5The content of this approach is that exogenous basic conditions determine market structure and that there is unidirectional flow of causality from market structure, through conduct, to performance. (Reid, 1987)from 1963 to 2005.Since 1962, the automobile insurance industry had been monopolized by one company under a strong government control until the industry was opened to 13 property and liability insurance companies including 2 foreign companies in 1983. Even after being seemingly the open market, the automobile insurance industry had been heavily regulated. All companies were required to use government-authorized premium rates, providing the same products at the same price.6There had been no price competition in the Korean automobile insurance industry. New entries to the market were virtually prohibited by the vague provision, so called ‘Economic Need Test’,7by which the government has the sole power to give a license to sell the automobile insurance.However, the regulatory environment was drastically changing with the 1996 affiliation with OECD (Organization for Economic Cooperation and Development) and the 1997 financial crisis.8By OECD, as a quasi-regulator, and IMF, as a creditor, the Korean government was strongly advised or/and required to remove government controls over the financial activities. Deregulation by external forces was directed to an open competition. One of two major changes in regulation was to remove an ‘Economic Need Test’from a license rule. Now anybody can do an insurance business if clearly specified entry conditions are met. Secondly, price competition has started since August, 2000 when an expense loading of gross premium was liberalized. One year later the expected claims cost, pure premium, can be determined by6The rating bureau, Korea Insurance Development Institute, had made gross premium rates based upon whole industry data until 2001, when the liberalization of premium loadings was getting started by individual companies.7‘Economic Need Test’ means that the government arbitrarily judges whether the country needs another insurance company when a company applies for a insurance license.8In 1997 to overcome a possible moratorium, the Korean government borrowed emergency funds from IMF, IBRD, and ADB.an individual company based on its own loss experiences.<Table 1: Recent Status of the Korean Automobile Insurance Market>Number of Firms, Entry and Market concentrationIn 1983 when the automobile insurance market was shifted to a competitive market from the monopoly, 13 property and liability insurance companies including 2 foreign companies took part in the market. All domestic companies were stock companies. There is no mutual company in the Korean insurance market. Until 1999 when one foreign company withdrew an automobile insurance line, there had been no change in the number of firms in the automobile insurance industry. In year 2000 one domestic company went into bankruptcy.9Only 11 companies started year 2001.In 2001 the first automobile mono-line insurance company entered the market after the entry regulation was changed. Two more mono-line companies joined the automobile insurance industry in 2003. Mono-line companies attacked the market with lower prices by using tele-marketing and internet marketing channels. With the advent of mono-line companies, real price competition started in the Korean automobile insurance market. As of March, 2006, 14 out of 28 property and liability insurance companies sell automobile insurance in Korea.<Table 2: Market Concentration in Automobile Insurance Industry>9This company was actually a foreign company since the company was purchased by a foreign capital a year ago.* Korea Fair Trade Commission considers a market concentrated if CR1≥0.5 and CR3≥0.75. ** The Horizontal Merger Guidelines issued by the US Department of Justice and the Federal Trade Commission classify markets as under: 0<HHI<1000, not concentrated, 1000<HHI<1800, moderately concentrated, and 1800<HHI, concentrated.Scale economiesThere is a big range in the size (in terms of premiums written as well as assets) of insurance companies selling automobile insurance in Korea. There are 4 companies with total annual premiums of over 1 trillion KRW and 10 companies with less than 1 trillion KRW. The so-called “Big 4” companies account for about 70% of the market. Usually it is of interest to ask whether or not the larger companies have a cost advantage over the smaller companies. Substantial cost advantages could indicate barriers to entry and the possibility that large companies could set prices substantially above marginal cost without provoking competitive entry. However, it is hard to expect that kind of pricing behavior since there was no price competition in the market before year 2000 when the tariff system was partially lifted.If there are economies of scale present, we would expect the expense ratio to decline with firm size. The economies of scale analysis performed here relates expense ratios to directpremiums written of only 10 out of 14 companies.10(Year 1999) ER = 38.72 －0.0000035DPW(29.45) (－1.811)R2 = 0.29(Year 2000) ER = 40.99 －0.0000059DPW(13.69) (－1.601)R2 = 0.24(Year 2001) ER = 33.66 －0.0000012DPW(23.99) (－0.827)R2 = 0.08(Year 2002) ER = 34.14 －0.0000017DPW(19.88) (－0.976)R2 = 0.11(Year 2003) ER = 34.82 －0.0000026DPW(36.18) (－2.656)R2 = 0.47(Year 2004) ER = 33.48 －0.0000011DPW(20.91) (－0.749)R2 = 0.07(Year 2005) ER = 38.34 －0.0000043DPW(12.77) (－1.498)R2 = 0.22,where ER = Expense Ratio and DPW = Direct Premium Written.The results of simple regression analysis provide only weak evidence of scale economies. Although the coefficient of the premium volume variable is negative in all cases, it is significant at the 5 percent level only in year 2003. Adding one more variable, a ratio of net premium to10Since one in bankruptcy and three newly entered companies have shown abnormal expense ratios, these companies are excluded in the analysis.direct premium to reflect reinsurance activity does not yield any better results. Distribution Channels<Table 3: Premium Distribution by Channels in Automobile Insurance>(KRW in billions)<Table 4: Expense Ratios of On-line Company vs. Traditional Company<Table 5: Premium Share of On-line Products>3. The conduct in the industryHow price is setThe way in which the volume, quality, and range of products are determined4. The Performance of the IndustryProfitabilitySince 1983 when the automobile insurance business was opened to the incumbent property and liability insurers, the insurers have complained that they are consistently losing large sums of money in operating the automobile insurance line. If they successfully convinced regulators, they were allowed to increase premium rates and improved loss ratios and underwriting profits. However, discussions of premium rates have often been based on misinformation about profitability in the industry.A traditional profit measure used in the property and liability insurance industry is the combined ratio. This ratio is very handy and provides some useful information about the insurance industry. However, it has often led to incorrect conclusions about profitability. The combined ratio, which is the sum of the loss ratio and the underwriting expense ratio, is used as an indicator of profitability. The loss ratio is an estimate of expected payments for reported and unreported claims, expressed as a ratio to earned premiums.11The underwriting expense ratio considers the expenses associated with writing insurance policies expressed as a ratio to earned premiums. A combined ratio over 100% indicates an underwriting loss. However, an insurance company can have a combined ratio over 100% and still be profitable, due to the fact that the combined ratio does not take into account earnings from investment income, which can offset underwriting losses.<Figure 2> shows the combined ratios of the automobile insurance industry from year 1983 to year 2005.11It is conventional that expected claims payments include loss adjustment expenses which are incurred to investigate and settle claims. In Korea, however, these expenses, about 2% of earned premiums, are considered a part of underwriting expenses. This practice allows the insurers to underestimate loss reserves.As a way to correct the combined ratio for investment income the overall operating ratio was introduced. The operating ratio is the combined ratio minus the ratio of investment income to premiums earned. Investment income is usually allocated by line on the basis of reserves (Cummins and Weiss, 1991) because data are not directly available on the investment income attributable to a particular line. To allocate aggregate investment income to the automobile insurance line, we assume that the share of total investment income is proportional to the share of total invested assets on the basis of the sum of unearned premium reserve, loss reserve and contingency reserve for the automobile insurance line. <Figure 3> shows the operating ratios from year 1983 to year 2005.The operating ratio is obviously a better measure of profitability as long as the insurers earn investment income from their invested assets funded by reserves to offset underwriting losses.<Table 5> shows the estimated profitability of automobile insurance from year 1998 to year 2005. The reason we choose year 1998 is that market valuation in assets and loan quality classifications have been used in the Korean insurance industry since 1998. However, the fair valuation method is not used in reserve valuations. If the reserves are not discounted, the claim payments that may not be made for several years are recognized as costs in the current year, thereby understating annual income.<Table 6: Estimated Profitability of Automobile Insurance from 1998 to 2005>(KRW in billions)Note: Underwriting gains/losses and operating gains/losses may not add or subtract due to rounding.<Table 7: Estimated Profitability of Property and Liability Insurance (except Automobile and Long-term Insurance) from 1998 to 2005>(KRW in billions)<Table 8: Estimated Profitability of Property and Liability Insurance from 1998 to 2005>(KRW in billions)* A rate of return on invested assets was only 3.67% compared to 8.12% of year 1999 due to stock market depression.** Rate of returns on invested assets: 6.05%(1998), 6.62%(2001), 4.33%(2002), 5.03%(2003), 5.48%(2004), 5.11%(2005)Affordability and Availability5. Policy Implications and Concluding Remarks<References>Cummins, J. D. and M. A. Weiss, 1991, “The Structure, Conduct, and Regulation of the Property-Liability Insurance I ndustry,” The Financial Condition and Regulation of Insurance Companies, edited by: Kopcke, R. W. and R. E. Randall, Boston, Federal Reserve Bank of Boston, pp: 117-154.Joskow, Paul L., 1973, “Cartels, Competition and Regulation in the Property-Liability Insurance Industry,” The Bell Journal of Economics and Management Science, Vol. 4, No. 2, pp. 375-427.Reid, Gavin C,, 1987, Theories of Industrial Organization, Oxford, UK, Basil Blackwell Ltd. Scherer, F. M. and D. Ross, 1990, Industrial Market Structure and Economic Performance, 3rd edition, Boston, MA, Houghton Mifflin.Smallwood, Dennis E., 1975, “Competition, Regulation, and Product Quality in the Automobile Insurance Industry,” in Promoting Competition in Regulated Markets, edited by A. Phillips, Washington, D.C., The Brookings Institution.Swiss Re, 2006, “World Insurance in 2005,” Sigma, No. 5., p. 35.Viscusi, W. K., John M. Vernon, and Joseph E. Harrington, Jr., 1992, Economics of Regulation and Antitrust, Lexington, MA, D.C. Heath and Company.05/31/07竞争与监管在韩国汽车保险业Wondon李*苏我Ewedemi ***副教授保险，大邱大学，韩国教授wlee@daegu.ac.kr**的金融学教授，克拉里昂宾夕法尼亚大学，美国ewedemi@1。

车辆工程毕业设计外文翻译

毕业设计（论文）外文参考资料及译文译文题目：Fuel supply system for an Internal Combustion Engine内燃机的燃烧供应系统学生姓名：学号：专业：所在学院：指导教师：职称：2014年 02 月 24 日Fuel Supply System For An Internal Combustion EngineAbstractA pulsation damper is provided between and in series with a low pressure fuel system pipe and a high pressure pump of a fuel supply system. During startup of an engine,low pressure fuel supplied via the low pressure fuel system pipe is injected from an intake passage fuel injector. When the fuel pressure is equal to or less than a fuel pressure at which good startability can be maintained,the pulsation damper closes off communication between the high pressure fuel system pipe and the low pressure fuel system pipe using the spring force of a spring.Key words: Fuel supply system; An internal combustion engine ;A pulsation damper;A low pressure fuel system pipe and a high pressure pump;A fuel supply system for an internal combustion engine,comprising: a low pressure pump that is capable to pressurize fuel; a low pressure fuel supply passage that is capable to supply fuel that was pressurized by the low pressure pump to a low pressure fuel injection mechanism which injects fuel into an intake passage; a branch passage that branches off from the low pressure fuel supply passage and through which the fuel that was pressurized by the low pressure pump flows; a high pressure pump which is capable to pressurize the fuel supplied via the branch passage,the high pressure pump being driven by the internal combustion engine; a high pressure fuel supply passage that is capable to supply fuel that was pressurized by the high pressure to a high pressure fuel injection mechanism which injects fuel into a cylinder; and a pulsation reducing mechanism provided on an intake side of the high pressure pump,wherein,when the internal combustion engine is started by only injecting fuel from the low pressure supply passage into the intake passage,the pulsation reducing mechanism closes off communication between the low pressure fuel supply passage and the high pressure fuel supply passage until a pressure of fuel in the low pressure fuel supply passage reaches a predetermined pressure value required for starting the internal combustion engine.Background of the invention :1. Field of the InventionThe invention relates to a fuel supply system for an internal combustion engine provided with a fuel injection mechanism that injects fuel at high pressure into a cylinder (i.e.; a fuel injector for in-cylinder injection,hereinafter referred to as “in-cylinder f uel injector”) and a fuel injection mechanism that injects fuel into anintake passage or an intake port (i.e.,a fuel injector for intake passage injection,hereinafter referred to as “intake passage fuel injector”). More particularly,the invention relates to a fuel supply system that can improve startability of an internal combustion engine.2. Description of the Related ArtA gasoline engine is known which is provided with a fast fuel injection valve for injecting fuel into a combustion chamber of the engine (i.e.,an in-cylinder fuel injector) and a second fuel injection valve for injecting fuel into an intake passage (i.e.,an intake passage fuel injector),and divides the injected fuel between the in-cylinder fuel injector and the intake passage fuel injector according to the engine speed and engine load. Also,a direct injection gasoline engine is also known which is provided with only a fuel injection valve for injecting fuel into the combustion chamber of the engine (i.e.,an in-cylinder fuel injector). In a high pressure fuel system that includes an in-cylinder fuel injector,fuel of which the pressure has been increased by a high pressure fuel pump is supplied to the in-cylinder fuel injector via a delivery pipe. The in-cylinder fuel injector then injects the high pressure fuel into the combustion chamber of each cylinder of the internal combustion engine.In addition,a diesel engine is also known which has a common rail type fuel injection system. In this common rail type fuel injection system,fuel which has been increased in pressure by a high pressure fuel pump is stored in a common rail. The high pressure fuel is then injected into the combustion chamber of each cylinder of the diesel engine from the common rail by opening and closing an electromagnetic valve.In order to increase the pressure of (i.e.,pressurize) the fuel in this kind of internal combustion engine,a high pressure fuel pump is provided which is driven by a cam provided on a driveshaft that is connected to a crankshaft of the internal combustion engine.Japanese Patent Application Publication No. JP-A-2005-139923 describes a high pressure fuel supply system for an internal combustion engine that can reduce vibrational noise when only a small amount of fuel is required by the internal combustion engine,such as during idling,while being able to deliver the necessary amount of fuel over the entire operating range of the internal combustion engine. This high pressure fuel supply system for an internal combustion engine has a two single plunger type high pressure fuel pumps each of which have a spill valve that spills fuel drawn into a pressurizing chamber that is divided by a cylinder and a plunger thatmoves back and forth in the cylinder,from that pressurizing chamber. When fuel is pressurized and delivered from the pressurizing chamber to the high pressure fuel system,the amount of fuel delivered is adjusted by controlling the spill valve open and closed. One of these high pressure fuel pumps is a first high pressure fuel pump in which the lift amount of the plunger is small and the other high pressure fuel pump is a second high pressure fuel pump in which the lift amount of the plunger is large. In addition to these two high pressure fuel pumps,the high pressure fuel supply system for an internal combustion engine also includes control means. The control means controls the spill valve of each high pressure fuel pump according to the amount of fuel required by the internal combustion engine,such that fuel is pressurized and delivered using only the first high pressure fuel pump when the amount of required fuel is small,and fuel is pressurized and delivered using at least the second high pressure fuel pump when the amount of required fuel is large.According to this high pressure fuel supply system for an internal combustion engine,of the two high pressure fuel pumps,the first high pressure fuel pump has a plunger with a small lift amount so the rate of pressure increase is small and a large amount of water hammer is also self-suppressed. That is,with the high pressure fuel supply system,the vibrational noise produced when the required fuel quantity is small can be preferably reduced by controlling the spill valve of each of the high pressure fuel pumps so that only the first high pressure fuel pump is used when the amount of fuel required for the internal combustion engine is small such as during idling. On the other hand,the second high pressure fuel pump has a plunger with a large lift amount so pressurizing and delivering fuel using at least this second high pressure fuel pump also makes it possible to deliver the required fuel quantity when the amount of fuel required by the internal combustion engine increases to the point where it can no longer be delivered by the first high pressure fuel pump alone. That is,providing two high pressure fuel pumps having plungers with different lift amounts in this way enables the required amount of fuel to be delivered throughout the entire operating range of the internal combustion engine,while reducing vibrational noise when the amount of required fuel is small.In Japanese Patent Application Publication No. JP-A-2005-139923,the high pressure fuel supply system for a V-type 8 cylinder internal combustion engine having an in-cylinder fuel injector in each cylinder is provided with a high pressure fuel pump for each bank. Tip ends that branch off from a low pressure fuel passage whichis connected to the fuel tank are connected to galleries of these high pressure fuel pumps. For each bank,a pulsation damper is provided midway between the branch portion of the low pressure fuel passage and the portion that connects with the gallery. This pulsation damper suppresses the pulsation in the fuel pressure in the low pressure fuel passage when the high pressure fuel pump is operating. At engine startup in this kind of a direct injection engine having only an in-cylinder fuel injector,fuel is unable to be delivered by the high pressure fuel pump until the engine turns over. Therefore,low pressure fuel is delivered by a feed pump to the fuel injection for in-cylinder injection. Therefore,the pulsation damper is designed to provide communication between the high pressure pipe system and the low pressure pipe system. For example,FIG. 6 is a sectional view of such a pulsation damper 215 ,FIG.7 is a sectional view taken along line VII-VII of FIG. 6 ,and FIG. 8 is a sectional view taken along line VIII-VIII of FIG. 7. As shown in FIGS. 6 to 8,grooves 223 A,223 B,223 C,and 223 D are provided in an end face (i.e.,the upper surface in FIG. 8) that abuts against a contacting member 226 A of the pulsation damper 215 . Therefore,when the feed pressure is low,the spring 226 D presses the contacting member 226 A against the upper surface of the member that forms the inlet 222 and the outlet 224 . In this way,the structure is such that even if pressure is applied by the spring 226 D,the grooves 223 A,223 B,223 C,and 223 D enable fuel delivered from the inlet 222 (i.e.,the feed pump side) to flow into the outlet 224 (i.e.,the high pressure fuel pump side) as shown by the dotted line in FIG. 8. On the other hand,as described above,an engine is known which includes,for each cylinder,an in-cylinder fuel injector that injects fuel into a combustion chamber of the engine and an intake passage fuel injector that injects fuel into an intake passage. In this engine,fuel is injected divided between the in-cylinder fuel injector and the intake passage fuel injector according to the engine speed and the load on the internal combustion engine. This engine is also provided with the pulsation damper shown in FIGS. 6 to 8.However,in this kind of engine,the following problems occur when starting the engine by injecting fuel with an intake passage fuel injector. When fuel is delivered by a feed pump at engine startup,the volume of pipe that needs to be charged with fuel becomes significantly larger. That is,when the engine is started with fuel injected from the intake passage fuel injector,despite the fact that fuel can be delivered to the intake passage fuel injector with the feed pump by simply charging only the low pressure pipe with fuel,the pulsation damper is structured such that the high pressure pipe system and the low pressure pipe system are communicated or open to one another. Therefore,fuel is unable to be delivered to the intake passage fuel injector by the feed pump unless both the low pressure pipe and the high pressure pipe arecharged with fuel. As a result,it takes time for the feed pressure to rise,thereby adversely affecting startability (i.e.,increasing the start time).Summary of the inventionThis invention thus provides a fuel supply system for an internal combustion engine,which is capable of improving startability of an internal combustion engine that includes a fuel injection mechanism for injecting fuel at high pressure into a cylinder (i.e.,in-cylinder fuel injector) and a fuel injecting mechanism for injecting fuel into an intake passage or an intake port (i.e.,an intake passage fuel injector).A first aspect of the invention relates to a fuel supply system for an internal combustion engine which includes a low pressure fuel supply passage that supplies fuel that was pressurized by a low pressure pump to a low pressure fuel injection mechanism which injects fuel into an intake passage; a branch passage that branches off from the low pressure fuel supply passage and supplies fuel to a high pressure pump that is driven by the internal combustion engine; a high pressure fuel supply passage that supplies fuel that was pressurized by the high pressure pump to a high pressure fuel injection mechanism which injects fuel into a cylinder; and a pulsation reducing mechanism provided on the intake side of the high pressure pump. The pulsation reducing mechanism closes off communication between the low pressure fuel supply passage and the high pressure fuel supply passage when a pressure of fuel in the low pressure fuel supply passage is lower than a predetermined value.According to this first aspect,the high pressure pump which is driven by the internal combustion engine does not operate during startup of the internal combustion engine. In this case,the internal combustion engine is started by injecting fuel that has been pressurized by the low pressure pump from the low pressure fuel injection mechanism via the low pressure fuel supply passage. In this case,during startup of the internal combustion engine when the pressure of fuel in the low pressure fuel supply passage is low,the pulsation reducing mechanism closes off communication between the low pressure fuel supply passage and the high pressure fuel supply passage. Therefore,fuel can be delivered to the low pressure fuel injection mechanism simply by charging the low pressure fuel supply passage with fuel using the low pressure pump. Accordingly,there is no need to charge the high pressure fuel supply passage with fuel using the low pressure pump so the low pressure fuel supply passage and the branch passage that provides communication between the low pressure fuel supply passage and the high pressure pump can be charged with fuel quickly,and fuel can bequickly injected from the low pressure fuel injection mechanism. As a result,startability of an internal combustion engine provided with a fuel injection mechanism that injects fuel at high pressure into the cylinder and a fuel injection mechanism that injects fuel into the intake passage or intake port can be improved.内燃机的燃油供应系统摘要在低压燃油供应系统管道和燃油供应系统的高压泵之间有一系列的有节奏的脉动衰减节气阀。

车辆工程专业毕业设计外文翻译5

TransmissionsTransmissions have to compromise on either ride comfort or efficiency, but a new approach to the dog engagement gearbox could improve both.With tightening emissions regulations, carmakers are not just confining their efforts to improving combustion and after-treatment. Many are finding that modern engines are so advanced that the benefits of some engine technologies are small compared to the huge development costs involved.It's important to look at the whole vehicle in order to improve emissions. As the second most expensive piece of kit in the car, the transmission is the logical next place to look.Of all transmission technologies, the manual gearbox is the most efficient; around 96percent of the energy that is put in comes out of the other end. But not everyone can drive one or wants to. Because you have to dip the clutch pedal, it's less comfortable to drive in heavy traffic. It makes the driver tired and the torque interruptions' head-nod effect on passengers can be wearing.The driver's clutch control and corresponding torque interruptions are also the manual's weak point. When accelerating up through the gearbox, each up-shift requires the driver to cut the torque momentarily by lifting the gas pedal and dipping the clutch. It may just take a second to complete the operation, but during this time the vehicle is losing speed and acceleration.At the opposite and of the spectrum is the traditional automatic. Its shift quality is good thanks to its torque converter, but efficiency is relatively poor despite recent advances. Because of this ,a lot of the current research is trying to find an efficient alternative to the conventional automatic.The main technologies are continuously variable transmissions (CVTs); dual clutch transmissions(DCTs) and automated manual transmissions(AMTs).They all offer different benefits over the conventional planetary automatic.The CVT uses a belt chain or toroidal shaped dish drive to vary an infinite number of gear ratios. It has improved efficiency and cost when compared to conventional automatics.Its advantage comes from its simplicitu. It consists of very few components; usually a rubber or metal-link belt; a hydraulically operated driving pulley, a mechanical torque-sensing driving pulley, microprocessors and some sensors.The transmissions works by varying the distance between the faces of the two main pulleys.The pulleys have V-shaped grooves in which the connecting belt rides. One side of the pulley is fixed axially; the other side moves, actuated by hydraulics.When actuatec, the cylinder can increase or reduce the amount of space between the two sides of the pulley. This allows the belt to ride lower or higher along the walls of the pulley, depending on driving conditions. This changes the gear ratio. A torodial-type design works in a similar way but runs on discs and power-rollers.The "stepless" nature of its design is CVT's biggest draw for automotive engineers. Because of this, a CVT can work to keep the engine in its optimum power range, thereby increasing efficiency and mileage. A CVT can convert every point on theengine's operating curve to a corresponding point on its own operating curve.The transmission is most popular with Japanese carmakers and Japanese supplier JATCO is a major producer. But in the US and Europe driving styles are different. Uptake has been slow despite Audi and other manufacturers having offered CVT otions on their ranges.The DCT is, in effect, two manual gearboxes coupled together. Gear shifts are made by switching from one clutch on one gearbox to another clutch on the other. The shift quality is equal to a conventional automatic, but slip, fluid drag and lydraulic losses in the system result in only slightly improved efficiency and acceleration over the conventional planetary automatic. Developing the control strategy is costly too."Recent advances in conventional automatic technology have weakened the argument to develop and set up production for CVT or DCT." says Bill Martin, managing director of transmission firm zeroshift. "Some carmakers have cancelled DCT projects because of the cost."The cheapest way to build an automatic is with an AMT. AMTs use actuators to replace the clutch pedal and gear stick of a conventional manual. They keep the high efficiency and acceleration of a manual gearbox, but the shift quality on some models is lacking. Torque interruptions and the head-nod effect are the most common complaint.so what is the alternative? There are always new ideas in transmissions, but Zeroshift says that its technology has efficiency benefits over a manual, delivering fuel economy improvements to city driving. Shift quality can also be equal to that of a refined automatic.Zeroshift's approach is an upgrade to the AMT. The synchromesh is replaced with an advanced dog enqaqement system.Dog engagement has been used for many years in motor sport to allow fast shifts. Conventional dog boxes are unsuitable for road use as the large spaces between the drive lugs or "dogs" create backlash, an uncomfortable shunt caused by the sudden change in torque direction.Zeroshift's technology solves this problem by adding a second set of drive dogs. It has also made each of the two sets of dogs only capable of transmitting torque in one or other opposing directions. "By controlling the engagement and disengagement of the two sets you can shift into the new gear befor disengaging the previous gear, "says Martin. "The shift quality is smoother than a typical modern six-speed automatic luxury car."The shift is instant and the torque is not interrupted.This philosophy is used for both up and down shifts."In conventional AMT there is an emissions spike during a shift due to the need to back off and reintroduce throttle, this is eliminated by going seamless, "says Martin. "This also reduces fuel consumption."It is a relative newcomer to the transmission sector, but the firm says that it is already attracting the attention of major European and US carmakers. The big draw is as a low-cost alternative to DCT, says Martin.Because the manual gearbox architecture is largely maintained, production costs and complexity are not greater than for a conventional AMT. Development of the controlsside is also considerably cheaper. Music to the ears of engineers trying to cut emissions and costs."Most of the carmakers have seen the system at least once," says Martion. "Some signed us immediately. Some have said not yet. None have said no. "That may be the clearest sign yet that when it comes to powertrain developments, carmakers are starting to focus on the transmission.HOW ZWROSHIFT WORKSThe hardware consists of two sets of bullets. mounted and actuated on two independent bullet rings. both sets of bullets run on the common hub, which is attached to the shaft with splines.Each bullet has a special profile. On one side they have an angled face for engagement. These are diagonally opposed, allowing the bullet to have a drive function for one gear and an overrun function for the other gear. The engagement faces taper backwards slightly to ensure the bullet latches onto the engaged gear under load.the opposite corners have a ramp, which pushes the bullet out of the previous gear once the new gear has been engaged.In neutral both bullet rings are positioned midway between the ratios. To select first gear, the bullets are moved into mesh with the engagement dogs.The bullets are actuated via shift forks conected to the shift actuators.The driving bullets lock first gear to the output shaft and transfer torque from the gearwheel onto the output shaft. The first gear overrun bullets are also moved into gear to lock the wheel to the output shaft in the opposite direction. This transfrs torque from the gearwheel onto the output shaft when the throttle closes and the engine overruns. This eliminates the backlash you'd expect from a dog engagement gearbox.To shift up with an open throttle, first gear's overrun bullets are unloaded and move in to engage second gear. This is followed by the previous driving ring which becomes unloaded when second gear is taken up.If the bullet is stopped from engaging fully-dog-face to dog-face-the second gear wheel opens an engagement window due to the relative speed difference. With the bullet pushed against the engagement dog compliance between the fork and actuator allows the stored energyto fire the bullet into the window.The first gear overrun bullets have now become the second gear drive bullets. As second gear takes over, the load is removed from the first gear drive bullets. These bullets are now no longer held by their retention angie and can be either moved out of gear by actuators or pushed out of gear by contact with the ramp face of the bullet.The first gear drive bullets then move across into engagement with second gear. In second gear, the roles of the bullets are reversed.Audi RoadjetAudi plans to add comfort, luxury and practicality without increasing emissionsThe Roadjet concept, first shown at Detroit in January 2006,indicates a number of technical directions that Audi going to take in the coming year. The firm is focusing on interior design, powertrain, chassis, electronics and safety innovations.These new directions will help Audi strengthen its position in the sub-luxury market that it previously had to itself. Audi has two main tactics to attract new customers in the US. It is breaking into the sports utility vehicle(SUV)and compact utility vehicle(CUV)markets.It also introduces new luxury and lifestyle features to strengthen its position in the US; sales there still lag behind those of BMW, Lexus and Mercedes-Benz. The recently launched Q7 off-road luxury vehicle is a late bid to capitalise on the SUV boom.In Europe, the carmaker's technical innovations such as aluminium construction, four-wheel-drive, and novel powertrain technologies have been successful. But if Audi wants to increase its US market share, it needs to innovate in those areas valued by American customers: comfort, luxury and practicality.Audi's designers have focused on this in the interior. They have devised a new wrap-around instrument panel shape to replace the more functional design in existing models. They have expanded the vehicle's multi-media interface (MMI)control system, used for cruise control, suspension, climate and entertainment separate controls. Combined with an upgraded climate system, occupants can set their own individual climate settings.Soft, warm, earthy colours are used in the Roadjet to create a feeling of well-being. The concept uses high quality functional materials: the upholstery is fine leather; the floor is neoprene. The space between the rear seats can house a range of optional equipment: the show car featured an espresso coffee machine. Storage boxes and baby carriers are more realistic alternatives.To enhance practicality, the rear seats slide backwards and forwards diagonally to increase shoulder and leg-room or rear load space. When the rear seats are in their most forward position, an oblique-facing child seat can be used behind the seats.Roadjet's load bay features an eletrically extending load floor to ease loading, offering unmerous lashing points to secure luggage items. The sliding seats and extending load floor are very likely to enter production on Audi's Q5 and A4 models.To heighten the sense of luxury, the concept uses a costly 1,000W Bang & Olufsen sound system with 14-speakers.This incorporates a "digital voice support" function that uses microphones and the car's speakers to pick up and amplify passengers' voices to ensure clear conversation even at high speeds.In a bid to improve road safety, convenience and traffic management, carmakers are working to common standards to develop a new in-car system to talk to other cars and roadside wireless olcal area networks. In traffic jams, bad weather or accident situations, cars send information to emergency services, other cars and traffic computers. The Roadjet concept featres previews such a system.The weight of all the new electronics and luxury equipment in this segment, combined with customers' growing demand for power is having a negative effect onexhaust emissions and fuel consumption. Audi is looking at sophisticated technical solutions to balance the equation.Roadjet's 3.2-litre gasoline direct injection engine is based on an existing engine but features a new fixed intake manifold with an integral vacuum reservoir to increase its output. This is combined with a two-stage cam operated variable valve lit technology to increase output.Despite the sports car performance, the Roadjet's overall fuel consumption is slightly lower than the current A4 Quattro 3.2FSI.The valve train technology, due to enter production later in 2006,lets the engine perform economically and smoothly during normal driving, switching automatically to more responsive, more powerful characteristics when the driver demands.Roadjet also has the first Audi application of speeddependent variable ratio dynamic steering for a stable highspeed motorway ride but with enhanced control on twisty country roads. Electronically-controlled variable rate dampers automatically adjust from soft and comfortable to firm and sporty to enhance safety and handling.Audi's engineers have electronically linked all of these systems to create three driver-selectable programmes: dynamic, comfort and sport. Each programme adjusts the dampers, steering, gearbox and engine eletronics to give different driving experiences.Roadjet's body styling marks a new direction for the carmaker.At 1.55m high with a wheelbase 4.7m long and 2.85m wide, the concept is roomy. The firm has used a combination of sharp feature lines and careully-sculpted concave-section doors to disguise the height. While the trademark LED tail lights are likely to enter production unchanged, steerable xenon gas discharge lights will replace the LEDs in the headlamps.Around the end of 2007 Audi will launch the Q5 CUV, based on the next A4 platform. Smaller and lighter than the Q7,it will be well placed to compete in the profitable CUV segment in the US. The Roadjet previews elements of the interior and exterior styling of this model.The Q5 will need to be more rugged to match the outdoor lifestyle image of the CUVsegment. At the same time, for the European market, the Roadjet's sharp style previews the next A4 model range, which may produce a new hatchback body in 2007 to join the conventional saloon and Avant estate. The dashboard and other new interior refinements are likely to spread across the rest of the Audi range over the next 24 months.变速器变速箱通常不得不在舒适性和效率之间做出选择，但一种新型的“犬牙啮合式”变速箱可以同时改善这两种性能。

汽车专业毕业设计外文翻译

On the vehicle sideslip angle estimation through neural networks:Numerical and experimental results .S. Melzi , E. SabbioniMechanical Systems and Signal Processing 25 (2011): 14〜28电脑估计车辆侧滑角的数值和实验结果S.梅尔兹,E.赛博毕宁机械系统和信号处理2011年第25期：14~28将稳定控制系统应用于差动制动内/外轮胎是现在对客车车辆的标准（电子稳定系统ESP、直接偏航力矩控制DYC ）。

这些系统假设将两个偏航率（通常是衡量板）和侧滑角作为控制变量。

不幸的是后者的具体数值只有通过非常昂贵却不适合用于普通车辆的设备才可以实现直接被测量，因此只能估计其数值。

几个州的观察家最终将适应参数的参考车辆模型作为开发的目的。

然而侧滑角的估计还是一个悬而未决的问题。

为了避免有关参考模型参数识别/适应的问题,本文提出了分层神经网络方法估算侧滑角。

横向加速度、偏航角速率、速度和引导角，都可以作为普通传感器的输入值。

人脑中的神经网络的设计和定义的策略构成训练集通过数值模拟与七分布式光纤传感器的车辆模型都已经获得了。

在各种路面上神经网络性能和稳定已经通过处理实验数据获得和相应的车辆和提到几个处理演习（一步引导、电源、双车道变化等）得以证实。

结果通常显示估计和测量的侧滑角之间有良好的一致性。

1介绍稳定控制系统可以防止车辆的旋转和漂移。

实际上，在轮胎和道路之间的物理极限的附着力下驾驶汽车是一个极其困难的任务。

通常大部分司机不能处理这种情况和失去控制的车辆。

最近,为了提高车辆安全，稳定控制系统（ESP[1,2]; DYC[3,4]）介绍了通过将差动制动/驱动扭矩应用到内/外轮胎来试图控制偏航力矩的方法。

横摆力矩控制系统（DYC ）是基于偏航角速率反馈进行控制的。

汽车专业毕业设计翻译中英文(全)lean remanufacture of an automobile clutch

LEAN REMANUFACTURE OF AN AUTOMOBILE CLUTCH Tony Amezquita*and Bert Bras**Saturn Corporation Systems Realization LaboratorySpring Hill, Tennessee Woodruff School of Mechanical EngineeringGeorgia Institute of TechnologyAtlanta, Georgia 30332-0405AbstractIn the history of manufacturing there have been three production systems, namely, craft production, mass production, and lean production. In many automotive remanufacturing operations, craft production and mass production systems are used as the basis for remanufacturing processes. The lean production system has proven to be more effective in the manufacture of automotive parts and it has allowed manufacturers who use it to produce in much greater varieties, with higher quality levels, and with lower costs. Hence, if used in remanufacturing, it would greatly enhance it. In this paper, a current remanufacturing process of an automobile clutch is analyzed, and a lean remanufacturing process is developed and compared to the as is process. Our findings indicate that the lean remanufacturing process provides a more robust process with lower costs when compared with the current clutch remanufacturing process that utilize craft and mass production practices.*Assistant Professor, corresponding author.**Remanufacturing Engineer.1 Our Frame of Reference – Remanufacture in the Automotive Industry Remanufacturing is the most economically sustainable form of reuse and recycling of manufactured goods, and it can be defined as the industrial process where worn out products referred to as cores, are brought back to original specifications and condition. In some cases, especially in the remanufacture of OEM automotive parts, remanufactured products exceed original specifications. The reason is that the latest engineering design and specifications, coupled with failure mode countermeasures derived from failure analysis, are used instead of the original specifications. The benefits of remanufacturing are many, but the most salient are:1) Remanufacturing salvages the material, energy, capital, labor, and emissions that wentinto the manufacture and material processing of products.2) The resulting production costs can often be lower than manufacturing, allowingremanufacturers to sell their units for 25 to 50% less than manufactured units with equivalent or better quality levels.These two benefits are the result of the fact that parts are reused and the embedded utility in the parts are maintained. Hence the resulting production costs, which should be considerably less than in manufacturing, allow remanufacturers to pass the savings on to consumers. Remanufacturing in the automotive industry can be divided into two groups; independent remanufacturers and Original Equipment Manufacturer (OEM) remanufacturers. Both of these activities in the domain of automotive products constitute the largest remanufacturing consumer market segment in the United States and Europe.In 1978, Kutta and Lund documented a survey capturing some of the issues important to remanufacturers (Kutta and Lund, 1978). However, we discovered in surveys and interviews with remanufacturers that many changes have occurred in the industry since then (Hammond, et al., 1996, Hammond, 1996). Major changes have been the restructuring of automotive companies into platforms and the trend towards mass customization of products. Especially the latter has resulted in what remanufacturers have termed “Parts Proliferation”, which refers to the practice of making many variations of the same product - differing only in one or two minor areas. However, these differences (such as electrical connectors) are distinct enough to prevent interchanging these similar products.The focus in this paper is on independent automotive remanufacturers, because they remanufacture component parts from most of the automobile manufacturers in the world, and for a very large number of model years. This being the case, independent remanufacturers are faced with a parts proliferation problem which cannot be successfully handled with their current production practices, that consist of a mixture of mass production and craft production practices. As described below craft production practices maintain production costs high regardless of volume, and mass production practices are not compatible with large product varieties. Consequently independent parts remanufacturers are loosing market share to aftermarket partsmanufacturers, and in some cases, remanufacturers are being forced out of the market, as in the case of clutch remanufacturing. For example, in 1989 the price difference between remanufactured and manufactured clutches was 50%. In 1994 the difference dropped to 20%, and getting out of clutch remanufacturingIt is our belief that the trends in mass customization and parts proliferation will not decrease and the small to medium sized independent remanufacturers seem to suffer most from these trends. Our surveys also point out the differences and sometimes hard “us versus them” attitude between independent remanufacturers and Original Equipment Manufacturers (OEMs), leading us to believe that the sharing of design information between OEM and remanufacturer is not a feasible solution and/or option in many cases. Hence, the only way we can help increase the remanufacturability of those products is by improving the remanufacturing processes.In this paper, we present some of our findings which, interestingly enough, indicate that the introduction of lean production techniques (which are one of the main causes of part proliferation and product diversity) in the remanufacturing industry, and hence creating lean remanufacturing processes, can lead to significant process improvements andto the current remanufacturing processes which are heavily batch oriented. In this paper, a solution to the parts proliferation problem of independent automobile parts remanufacturers is developed by transforming a current remanufacturing process of an automobile clutch into a lean remanufacturing process. This lean clutch remanufacturing process has been developed in great detail in (Amezquita, 1996). In this paper, we will discuss the as-is process, followed by a discussion on how to convert this process into a lean remanufacturing process. It should be stated up-front that although the proposed lean process offers substantial savings, it has not been implemented by the company who supported this case study. First, however, we will provide the necessary background on craft, mass, and lean production systems.2 Craft, Mass, and Lean ProductionIn the 1800s, automobile manufacturing was the domain of the skilled craftsmen who controlled most of the activities on the manufacturing floor. These skilled craftsmen designed and built customized vehicles by making and fitting each part by filing it down until it mated with the other vehicle parts. Even if craft producers could make 10,000 identical cars, the price per car would not have dropped by much, because each car was essentially a prototype. The biggest benefits of this craft production system in the automotive industry were that:•customers were able to obtain products which specifically met their needs, and•workers were satisfied, proud, and fulfilled, and their goal was to hone and perfect their skills and one day become independent owners.At the turn of the century, Frederick Taylor removed the control of the manufacturing operations from the hands of the skilled craftsmen by creating divisions of labor. This was the first step towards the development of mass production, which was fully implemented by Henry Ford. Taking the developments of Taylor, Ford added the standardization of the production of parts, which led to complete parts interchangeability, which in turn led to the simplification of parts assembly. In 1908, an assembler was spending 514 minutes (8.56 hours) assembling a large portion of the car before moving to the next car (Womack, et al.,To reduce the cycle time of assemblers (period of time spent with each vehicle by each employee), Ford had each assembler perform a single task and move from vehicle to vehicle in the assembly hall. The cycle time per vehicle was reduced from 8.56 hours to 2.3 minutes (Womack, et al., 1991)! Finally, the simplification of assembly tasks allowed Ford to utilize the moving assembly line to bring the cars to the assemblers and eliminate all the walking previously done. In addition, the moving assembly line enforced a faster and even work pace. Ford’s implementation of the moving assembly line, which brought the car past the stationary worker, cut cycle time even further from 2.3 minutes to 1.19 minutes (Womack, et al., 1991).Ford discovered that his new system reduced the amount of human effort needed to assemble a vehicle, and with the same number of people, equipment, etc., the more standardized vehicles he produced, the more the cost per vehicle dropped (economies of scale). By the time Ford reached volumes of two million identical vehicles per year, he had slashed the real cost to the consumer by an additional two thirds from the time he started production of the Model T in 1908. Consequently, a production system which most closely resembles the mass production system can bring substantial savings to a remanufacturer, and is often advocated. However, this system runs aground when confronted with a large variety of parts, which is the current situation many independent automotive remanufacturers are facing. Most automotive parts remanufacturers (and other remanufacturers) still rely on craft production systems to handle the variability in the number of parts to be remanufactured and the variability inherent in refurbishing operations due to wear differences. However, as noted already by Henry Ford, craft production system has two main drawbacks:1) Production costs remain high regardless of volume (economies of scale are not possible,e.g. Ferrari Automobiles).2) Quality, consistency, and reliability are poor due to the lack of standardization.Thus, a different approach to remanufacturing which uses elements of the mass and craft production systems may prove to be more suitable for automotive parts remanufacturing.Lean production takes the best elements of the craft and mass production systems. This system was developed by the Toyota Motors Corporation, and later is was implemented by all Japanese automotive manufacturers. Lean production can be defined as an entire production system with the following fundamental characteristics:1) Economies of scale (from mass production),2) Production of large varieties of products (from craft production),3) Elimination of non-value added resources and activities, and4) Integration of all production system elements and functions to obtain long term functionalrelationships.Compared to the lean production system, the traditional mass production system can be fundamentally defined as having the following characteristics:1) Economies of scale,2) Very limited range of product varieties,3) Non-value added resources and activities are perceived as necessary, and4) Division of all production system elements and functions to obtain specializationresulting in short term strained relationships.Given the fact that the lean production system is most suitable for the production of large varieties of products, and it allows the attainment of economies of scale, it would seem that using this production system as a basis for remanufacturing processes would provide better results than the ones currently obtained, which are forcing independent parts remanufacturers away from remanufacturing. In the remainder of this paper the remanufacturing process of an automobile clutch at one of the largest independent automotive parts remanufacturers is used as a case study.3 Automobile Clutch Remanufacturing at RaylocThe Rayloc Company is a division of the Genuine Parts Company which provides aftermarket replacement parts at 6,500 NAPA Auto Parts stores nationwide. Rayloc is one of the largest automotive parts remanufacturers in the world, and they remanufacture parts such as alternators, starters, drive shafts, brake master cylinders, calipers, wiper motors, window lift motors, rack and pinion units, steering boxes, power steering pumps, brake shoes, disc brakes and clutches. The focus of this paper is placed on the remanufacturing process of clutches.The clutch remanufacturing process at Rayloc was analyzed for six months at one of the remanufacturing plants. The process material flow is represented schematically in Figure 1.Figure 1 - Current Clutch Remanufacturing Process Material Flow With BatchingIn this process cores are supplied by customers, and are accumulated randomly in drums without identification at the NAPA jobbers or retailers. Cores (c1, c2, etc., see Figure 1) are then identified and sorted by part number and manufacturer, and are again accumulated in a core warehouse at the Rayloc plant. Based on a forecast, cores are removed from a core warehouse and processed in a batch. Batches of the same part number are randomly mixed and the reusable components are assembled together with replacement component parts. Non-reusable components are recycled after work has been done on them. The remanufactured cores (rc1, rc2, etc., see Figure 1) are placed in a finished goods warehouse to start the cycle over again after a customer buys the remanufactured clutch. The assumption behind this remanufacturing process is that identical cores can be easily collected into economic batches and together they can be disassembled, cleaned, inspected, refurbished, and reassembled. The process is distinguished by having large enough volumes to obtain some form of economies of scale. The practice of batching in remanufacturing was adopted from mass production, but batching is also done in remanufacturing for the purpose of cannibalizing reusable parts and reduce the need to purchase new manufactured replacement parts. Purchasing manufactured replacement components is for the most part more expensive than cannibalizing cores. In fact, a fundamental principle of economic remanufacturing is the maximization the reused content in finished remanufactured products.After the completion of the study, the clutch remanufacturing process was characterized using the criteria as shown in Table 1. The characteristics of this process reflect the problems and issues independent auto parts remanufacturers face, and are not indicators that Rayloc is poorly run. In fact, Rayloc is one of the most efficient remanufacturers in the U.S.A. with a proven track record exemplified by the fact that Rayloc’s remanufactured clutches are still selling well, in a timewhen other remanufacturer s’ clutches are being phased out from the market.The relatively long processing lead time requires the use of a warehouse to buffer the factory from the market. When product varieties are small, this approach does not require the need to store a large quantity of parts, as was once the case in the 1960s at Rayloc, when remanufactured remanufacturing process (LeCour, But when varieties are large, inventory levels in the warehouse increase considerably, and customer service levels drop.4 Designing a Lean Process for Automobile Clutch RemanufacturingA lean remanufacturing process must have the following elements as stated earlier:1) Economies of scale (from mass production),2) Production of large varieties of products (from craft production),3) Elimination of non-value added resources and activities, and4) Integration of all production system elements and functions to obtain long term functionalrelationships.In the following sections, we present how these elements can be achieved for the Rayloc clutch remanufacturing process.4.1 Obtaining Economies of Scale and the Ability to Handle Large Varieties of Products In order to obtain economies of scale, one must do what Henry Ford did: standardize. However, in traditional remanufacturing processes it is very difficult to standardize because of the(Guide,1996). This argument is applicable in the remanufacturing shop which utilizes a job shop layout and the work is performed in a manner consistent with the craft production system. Thus, the first step in obtaining a lean remanufacturing operation is to move away from craft production or “artisan work” and create a standardized process. This however, cannot be done in the same fashion Ford did. At the beginning of the century, Ford relied on hard automation to standardize the production work, and thus eliminating adjustments, in contrast to craft production where multi-purpose machines require various adjustments which require skilled craftsmen. Ford had standardized all the tooling and tasks so well that he practically eliminated all adjustments. The penalty with this system was that he had no flexibility to switch between models with the same machinery. When Ford redesigned the Model A, he discarded the machinery along with the old model (Womack, et al., 1991). To obtain standardization and eliminate adjustments, but still maintain the flexibility to handle a large variety of parts or models, flexible or programmable automation is needed in a modern process.the following features (Chang, et al.,1) High initial investment2) High complexity3) High programming costsIn this paper, the concept of Lean Machines is developed for the purpose of counteracting the above mentioned drawbacks of programmable automation. The concept of Lean Machines is derived from the Nagara system, which is a recent development of lean production to further reduce lead times and eliminate waste. The biggest accomplishment of this development is the obliteration of boundaries between departments. In other words, this development allows for a comprehensive and coherent one-piece-flow, without the need to transport parts to the paint department, stamping department, the cleaning department, etc. A production example illustrates the concept of the Nagara System.“After machines perform the drilling and tapping on the line, parts are placed in one-meter cubical box that is, in fact, a device for spray-painting parts. Closing the lid of the box trips a switch and sets the operation in motion. Small fittings and wires are attached to the parts in a one-piece flow after they are removed from the box. More than one hundred of these boxes have been integrated into processing and assembly lines. This has eliminated approximately 80 percent of the painting which earlier required moving parts to the painting shop” (Shingo, 1989).Thus, Lean Machines are simple, small, and automatic machines which can be designed and built with a small budget. In order for machines to cycle automatically, they must have some form of controller. Ford’s dedicated machines, were controlled with the use of mec hanical mechanisms such as cams, governors, ways, slides, and pistons (Chang, et al.,modify. The most versatile control is provided with digital controllers, because the control logic is programmed into the controller memory using software. Lean Machines make it possible to standardize the work done with machines, while at the same time process a large variety of part numbers. Thus, Lean Machines differ from Ford’s machi nes in that they allow considerable adjustments, but are similar to Ford’s machines in that the adjustments are standardized or saved in a programmable memory. By being able to capture the knowledge of many craftsmen in the memory of the machines, all the tasks previously performed by craftsmen, including setups, can be stored and recalled as dictated by customer orders. Thus, the “wheel does not need to be reinvented” every time a different part number is remanufactured.An example of a Lean Machine is presented here with the use of the assembly operation shown in Figure 2. With a Lean Machine setup times for this assembly operation can be reduced from an average of 42 minutes to seconds, in big part due to the elimination of adjustments.Figure 2 - Riveting the Diaphragm to the Clutch CoverDuring a setup change, the steps given in Table 2 are performed.Table 2 -To reduce the setup times from 42 minutes to seconds, the first step is to eliminate the use of intuition and skill to adjust the machine (element #6) and “reinvention of the wheel”. The current machine adjustments required during the setup are illustrated in Figure 3.Figure 3 - Adjustments Required to Setup “Riveting Diaphragm to Cover” Operation The adjustment of the punch that presses the rivets down requires that two bolts be loosened, and the punch be placed exactly in middle of one of the nine fixture indentations where the rivets are placed. The fixture indentations provide the operator with an exact location where the rivets must be placed. This punch adjustment must be done by trial and error, because there is no reference point that can be used to guide the adjustment of the punch relative to the fixture. But before the punch can be placed in the correct location, one of the fixture indentations has to be lined up to the punch. Three Allen head screws are used to hold the fixture base in place, and every time the fixture needs to be adjusted, the three screws need to be loosed and tightened again. The most difficult part of the setup for this machine is that as one of the references is moved, such as the punch, the fixture must also be moved. Once an adequate adjustment appears to have been made, tests with rivets must be performed to check the setup. Many times the position of the punch relative to the fixture is not precise, but it takes so much time to position the two elements precisely centered relative to each other, that the operators choose to startprocessing parts and punch rivets off-center. This practice deteriorates the appearance of the cover.A solution to the setup problem is to standardize the settings by storing them in programmable memory and using a modified 3-Jaw Chuck fixture with nine locator pins as shown in Figure 4. Nine pins are used because most automotive clutches use nine rivets to attach the diaphragm to the clutch cover.Figure 4 - Using a 3-Jaw Chuck as the Basis for a Nine Pin Assembly FixtureThis mechanism includes the use of stepper motors, which take the place of the chuck handle, and a digital motion controller system. Motion controller systems usually contain a battery backed Random Access Memory (RAM) that can store various programs when stand-alone. A Remote Panel Operator Interface, which is usually connected via RS-232-C Serial Communication interface, can be used by the operator to enter the part number to be processed each time. Based on the input on the remote panel and the algorithm in the programmed memory, motion controllers, through the stepper motor drivers, send out a series of electrical pulses to the stepper motor which cause the motors to step fractions of revolutions or step angles and place the locator pins at standardized locations. The complete mechanism is shown in Figure 5. This mechanism, which can be placed on a simple hydraulic press, constitutes a Lean Machine.Figure 5 - Mechanism to Standardize Assembly Fixture SettingsElements #3, 4 and 5 of the setup operation depicted in Table 2 are also eliminated with the use of this Lean Machine, since the information pertinent to the part number is stored in memory, and fixtures do not need to be exchanged. To completely reduce the setup time of this operation to seconds, setup elements #1 and 2 can be eliminated by storing replacement component parts, such as rivets and shims at the exact point of use and easily accessible. In addition, workers do not need to gather the core components, because these components arrive at the time needed from up-stream operations. Thus by placing the components at the point of use, and using a lean machine to standardize the machine adjustments needed to process different part numbers, setup times for this operation are reduced to seconds.4.2 Eliminating non-value added resources and activitiesTo remove non-value added resources and activities from a process, we must understand what these are. In lean production there are six non-value added wastes, as shown in Table 3.To eliminate or reduce the waste of overproduction, a remanufacturing operation must only make what has been ordered already in order to eliminate the need to have a finished goods warehouse, and all the storage and handling costs associated with inventory management. This is only possible if the complete remanufacturing process is lean enough to have production lead times measured in minutes.To obtain a process with very short lead times, the parts that enter a remanufacturing process must be kept free of delays or wastes of waiting. Delays in a production system stem from the use of batches or lots. These delays can be referred to as batch delays and process delays. Batch delays are a function of the size of the batch. The larger the batch size, the more a batch must wait for the last part of the batch to be processed before the batch can be moved to the subsequent operation. Process delays are caused by an imbalance in operation cycle times. In remanufacture, large batches are used for the purpose of:a) spreading production costs and setup times, mostly stemming from time consumingsetups, over a large set of parts,b) allowing for cannibalization of component parts, andc) serving as a buffer between unbalanced operations.Over the years, setup times have remained high because in production facilities it is for the most part assumed that substantial reductions in setup times cannot be accomplished,based on the1913 (Spearman and Hopp, However, lean producers have shown that setups times can be brought down from hours to minutes. Using Harris’ model, large batches are mistakenly perceived as large volume production, b ut by reducing setup times, large volume production can be attained with greater varieties and smaller batches. In fact, the use of large batches has a constraining effect on the throughput of a factory. This phenomenon can be explained with the use of L ittle’s Law, which states that as the amount of work in process (batch sizes) increases beyond a critical work in process level, the speed of the process slows down. The ideal work in process level is equal to the number of operations within a of one (Spearman and Hopp,effect that causes highway congestion. When the number of cars in a given highway is higher than the critical number of cars, the speed of the flow of cars slows down. Thus, to obtainshorter lead times, i.e., higher throughput speeds, the batch sizes should be reduced to one. Consequently, fast setups are needed by means of lean machines.However, if batch sizes are reduced to one, cannibalization is no longer possible. Thus, in order obtain batch sizes of one, cannibalization needs to be eliminated. Purchasing replacement parts is the most costly alternative for automotive parts remanufacturers, because they are not readily available, and the varieties of parts to be stocked increase storage costs considerably. Furthermore, “new” replacement parts that are not standard parts are very expensive. Another option is to introduce the use of additive technologies into the remanufacturing process to restore worn components by adding (new) material. Additive technologies allow remanufacturers to salvage component parts which would otherwise have to be replaced. The additive technologies that are used in the lean clutch remanufacturing process are:a) Arc Metal Spraying, currently used in many remanufacturing and manufacturing plants,which is used to refurbish the clutch pressure plate, andb) Fusewelding, developed by the Wal Colmoloy company, which is used to refurbish theclutch diaphragm.As stated before, large badge sizes also commonly serve the purpose of buffers for lengthy processes. In the clutch remanufacturing process, an example of this is the buffer needed for the lengthy process of thermally degreasing batches from the other operations in the process. Thus, to reduce the batch size and allow greater product variety, a degreasing operation that does not require a lengthy cycle is needed. However, at the same time it must be environmentally benign to maintain environmental compliance costs low. The technology proposed in the lean clutch remanufacturing process is known as Hydrohoning. This technology contains a pressured spray of water and media to simultaneously degrease and abrade component parts in a single operation. This technology has a closed loop system and does not use any detergents. With the above mentioned changes in operation technologies, batch sizes can be reduced to one and the waste of waiting can be substantially reduced.With the waiting wastes removed, the lean remanufacturing process flow can now be standardized by generating the appropriate tact time1 for the process based on the daily output of salable clutches. For the specific clutch remanufacture process under consideration, the daily market demand was obtained from average sales in 1995 and the current conditions in the aftermarket clutch sector of the market. Taking 314 as the daily salable quantity of products, and given that a working shift consists of 7.5 hours, the tact time is set at 1.43 minutes. Thus, the machine cycle time and the tending time of the machine for each operation cannot exceed 1.43 minutes. The use of a process tact time is how the “stochastic nature of the amount of work” needed for each worn out part in remanufacturing is absorbed. For example, the wear of a clutch pressure plate varies considerable from core to core, requiring longer metal spraying times for more worn plates. However, with a tact time of 1.43 minutes the metal spraying operation can be designed to take a maximum of 1.43 minutes (including operator tending time) for the worst case 1 Tact time is the uniform time allocated to all operations based on the daily salable quantity. For example, with a process tact time of 1.5 minutes, work in process must be moved to the subsequent operations every 1.5 minutes independent of the machine cycle time. With this tact time, 320 units would be produced in an 8 hour working day.。

车辆工程专业毕业论文外文翻译---履带车辆转向机构的研究现状及发展趋势

The Track Vehicle Changes Direction Research Present Condition and DevelopmentTrends of The Organization1 change direction the research present condition of the organizationDifferent classification in basis method, the track vehicle changes direction organization can according to vehicle is in change direction process the power flows of deliver the way is divided into the single power flows to change direction the organization to flow to change direction the organization with a power, and also can according to in change direction process two the sport of side trackses have no the contact but is divided into the independent type change direction the organization with bad soon the type changes direction the organization.1.1 single powers establish a certain changing direction the organization after flowing change direction the single power in organization flow to change direction the general structure in organization method is at became soon the organization, is the most simple method to constitute track vehicle change direction to spread to move.The single power flows to change direction the organization to change direction the organization most in brief, among them most in common usely change direction the clutch, single bad soon the machine, double is bad soon the machine, planet changes direction organization etc..Change direction the clutch[1,2] is all a friction that several types rub the clutch, depending the friction surface to deliver to turn the , being the separation some on changing direction the clutch laterally, can reduce or cut off that side drive a round delivers of turn the make vehicle changed direction.Change direction the size of the radius from drive a decrease for spreads to turn the measures namely the degree that clutch separate decides.Change direction the clutch is simple because of the construction, manufacturing convenience, got the extensive application on the small scaled track in inside in earlier period type tractor, bulldozer.But because its manipulatethe sex bad, produce the efficiency low, can consume bigger, enlarge continuously along with the track vehicle power, change direction the application of the clutch will suffer certainly of restrict.SingleBad soon the machine changes direction the organization[2,3] can make vehicle several why the speed of the center position still keeps in change direction process the original driving the car straightly is soon, being a When the complete system in side move, change direction the radius over small, but another side track speed over high, change direction the Cape speed over big, for this reason a power for needing changing direction power very bigly, would outrunning generally launching machine restrict, if the pilot keep on changing direction, have a little bit the immodesty and then will make launch the machine fire, as a result can depend to slip to whet, using than the greater half path changes direction, or pole is not fair and softly break to change direction continuously with the lesser half path.Therefore this kind of is single bad soon the machine change direction the organization to no longer adopt almost now.The speed that a speed for differing soon machine changing direction organization[3,4] can making track vehicle at changing direction slowly soon side track lowering is equal to the fast side track the increment, the for this reason vehicle changes direction of average speed and straightly the speed that drive same alike.But because a variety for badly soon machine can't completely system moving first side track, vehicle can't originally changing direction, and changing direction radius scope has no usage to change direction the clutch big, changing direction the going smoothly worse.While changing direction, the fast side track accelerates, therefore launching the affixture of the machine carry the ratio adoption change direction the clutch big.The double is bad soon the machine be constituted by wheel gear of change direction the organization, with change direction the clutch compare the spare parts number little, bear to whet the sex good, the life span is longer.The planet changes direction the organization[4,5] moves with the system from a planet a department the machine constitutes.The operation planet the system on the organization moves the machine can change two sides drives the round drives the dint size make vehicle changeddirection.It is that type of to change direction the organization opposite in change direction the clutch change direction the organization can deliver the bigger changing direction the dint , can realize an athletic and fixed stalk wheel gear organization fall through of two free a planet for of flat-out decomposition with synthesizing, planet organization a three dollar as have the bad relating to soon; change direction the organization to much order to deliver the motive, and the internal path in organization faces the dint mutually equilibrium.But is complicated because of its construction, only industry in big power tractor, bulldozer and other heavy type vehicle last application.Single weakness that power change direction is obvious, vehicle only contain several fix of change direction the radius, press to rule not of change direction When the radius change direction, want to is slipped by friction a piece to whet to realize, and is hard to get the stability change direction the radius accurately; the next in order in change direction process rub a dollar piece of violent slip to whet to will bring to have fever with wear away, make spread to move the efficiency lower, especially in the big power change direction work appearance next, would exsit the bigger power lose, with the result that often need to be declined to change direction soon; moreover, the violent friction also make easy damage in organization, cause the work dependable bad, the life span lower.1.2 pairs of powerses flow to change direction the organization after launching machine, will launch the machine power be divided in to become soon with change direction two roads be juxtaposed to deliver, ising a double of powers to flow to change direction the organization.A power flows to change direction the organization will used for keeping the pushes forward of become soon the organization is different from result in leftly, the right side track speed differs of change direction the organization to be juxtaposed in spread move department, change direction the organization when the vehicle keeps the did not result in twoth the speed of side trackses are bad, while changing direction, became to flow each file of offering soon to drive the speed straightly with change direction the organization results in of two the speed of side trackses differ to remit to flow, realizing the vehicle change direction.(1)the machine type a power flow to change direction the organization to flow the foundation top that change direction the organization to appear at the earliest stage in the single power of was a machine to kept the with changed direction two powers flowed all from machinery to realized type a power to flowed to change direction the organization[3].It is this kind to change direction the organization main from two become soon box( a lord become soon the box, a cent moves a box of), the planet wheel gear organization, clutch moves with the planet organization system the machine constitutes, the single power flows to change direction in changing direction function the organization has the very big increasing, but it still change direction the radius is to have the class.The file is more low, getting of change direction the radius more small; the file is more high, getting of change direction the radius more big.Can't still adapt to the vehicle road in all different curvatures on the tactful track that change direction to drive with the demand, also can't expel parts of coalescences rub a piece proceeds to slip to whet to change direction and from slip to whet an a series of problem for bringing.(2)the machine liquid press type a power flows to change direction the organization machineThe type of changes direction the organization changes direction the function easily under the influence of the pilot's driver's technique, physical strength term moving the machine to wear away with the clutch, system, and bring the pilot the fatigue easily.Give or get an electric shock along with the machine the liquid press and technical development in engineering in machine in person, the machine type change direction the organization to will be eliminated on the big power tractor, bulldozer...etc. engineering vehicle necessarily.Press in the l ast additional liquid in system in machine the liquid of —that pump the motor presses the machine — liquid drives to press to change direction the system will get the application gradually.The machine liquid press type a power flows to change direction the organization[5,6] from launch the machine and change the deal pump, control valve, fixed amount motor, many files become soon box and empress bridges change direction to differ to move the organization constitutes.Itwill spread to flow from the machine that launch the machine power in many files became soon the importation stalk of the box last cent flow, all the way flow through was pressed by liquid pump- liquid press motor constitute of change direction adjust soon system; another all the way flow through many files became soon box, finally experienced star row top confluence, then was lined up by planet of some a the parts( such as planet) spread to the vehicle to spread to move the stalk top eventually.Because the liquid presses to pump to press with the liquid the motor can have no the class controls, therefore using the this type of changing direction the organization since can acquire the carAn a lot of weakness for twoth lateral speeds differing realizing having no class controling, again overcoming machine type changing direction organization.If the liquid presses the motor do not work, only coming from central spread the dynamic power flow, the vehicle makes the straight line drives; if only have the liquid that come from the power press the motor flows, the vehicle can realize to change direction radius as the zero changing direction originally; if input at the same time two road powers flow, because the liquid presses the motor can realize to have no the class controls, for this reason vehicle two side tracks drive the rotation to have soon and will barely do much more endless, can get the much more endless changes direction the radius, can immediately realize to have no the class changes direction, pilot as long as manipulate to change direction the dish turns to move the liquid presses the device, can make vehicle driven along the certain arc stablely.This kind of changes direction the organization not only have the construction good, have no the friction a piece, life span is long, the efficiency is high and work dependable, arrange simple, maintain the adjustment little and lower to can consume to wait the characteristics the outside, but also it is not a motive to pass the part or cut off all a side track in working function to the system move a the side drives a the round realizes to change direction of, but two side tracks deliver the motive always, can realizes nicely like this the motive change direction, basic ascend a safety for slippery phenomenon, being applicable to proceeding being partial to carrying pushing soil with cutting off root homework; at sloping fields changing direction can't appearing" conversingdirection" phenomenon, increases vehicle that dissolves the track; because of changing direction do not cut off the motive, the average car of the for this reason vehicle does not lower soon; the track do not stop driving, breaking to the soil little, in loosenning soft soil of pass the sex good; change direction the size of the radius can control arbitrarily, increasing the flexibility of the track vehicle, change direction steady; change direction vehicle can develop with drive the high work in same function straightly; realizes easily a the root manipulates the pole to control in to back with change direction.2 change direction the pure liquid in trend(1)in development in organization press to have no the class changes direction the organization wants to realize the track vehicle changes direction the radius can control and continue to have no the class changes of change direction the function, the adoption capacity type liquid presses to pump to press with the liquid motor etc. has no the class become soon a piece is a more realistic viable method.The pure liquid presses to change direction the organization[7 9] of ～ss pass to pump of positive and negative two directions have no the class changes the deal regulates, realizing to launch the mobile dint was spread by double to move to change direction the road arrives to remit the popular star row has no the class changes of spreading and moving ratio, end realize the vehicle face or so two change direction laterally radius can continue to have no the class the variety keeps the , pass the liquid press to pump with the liquid press the motor shuts the lock( change the row that deal pump measureses for zero) to realize to change direction the zero to shut the lock axially, from but keeps to keep the stablely.Under the situation of becoming soon the organization hangs the blank on schedule to change direction, launch machine a power for sending out all to press from the liquid that change direction the road a piece deliver, can realize the vehicle change direction originally.The current liquid presses the industry level returns the hard getting the power enough and big and the good liquid in function presses a dollar an efficiency for, and the liquid presses the system low, this is the biggest obstacle that pure liquid press to have no the class change direction the technique develops.(2)the compound changes direction organization as to overcome the pure liquid presses the above blemish that change direction the organization, appearing now the small liquid in power in various adoptions press the liquid of a dollar piece presses the compound changes direction the project[7].A pump a motor project: this project is to solves the liquid press the direct and the most simple project in shortage in a power in a dollar, its function press with pure liquid to change direction same, but two sets of liquids press a piece merge to make the organization's physical volume weight bigger, the efficiency is still lower.The machine liquid presses to reunite the project: that project is adopting a double of flowing the liquid press to change direction of at the same time, reserve a set of machines change direction the organization.Make use of the power not very of the liquid presses a dollar the piece realizes the greater half path changes direction of have no the class variety continuously; make use of the organization that machine change direction lesser half path realizes the class changes direction.This kind of change direction the organization falls through whole radius scope has no the class variety.A radius liquid presses to change direction the project: that project adoption contain two kinds of exportations soon the liquid that compare presses the motor, when the good road ascends to change direction adoption the higher exportation turns soon, native out of fix the hour then change to output with the low speed to overcome bigger changing direction the resistance.The liquid presses the liquid dint compound changes direction the project: that project presses with the liquid of the limited power a piece proceeds to have no the class changes direction, the help matches the machine accidentally at change direction the liquid press the motor dint not enough hour on time provide the help .That project although reduce the liquid press a piece efficiencies would be much lower.In fine, adopt the liquid press a dollar a point for having no class becoming soon characteristic to realizing track vehicle having no class changing direction is good choice, solving liquid pressing a dollar a power shortage then is low with the efficiency that direction is investigative.(3)the machine liquid presses the consecution has no the class changesdirection the organization machine liquid presses the consecution has no the class changes direction the organization[10 21] of ～ss are in simple liquid pressing cent in machine spreading the foundation that move the principle, adopting the different machine organization parameter combine, and press with liquid a dollar the piece matches with of a kind of latest model changes direction the organization.It can guarantee at continue to have no the class output the next applied small liquid in premise that turn to press the total power in an exportation for significantly increasing vehicle in a dollar soon, and its spread to move the efficiency far far ahead pure the liquid presses to change direction the organization spreads to move the efficiency.It represents the development direction that track vehicle change direction organization.The research develops the good machine in function liquid presses the consecution has no the class changes direction the organization, excellent turn to match the that type of turning. Construction parameter that face organization is the point lesson of the current vehicle engineering realm.履带车辆转向机构的研究现状及发展趋势1、转向机构的研究现状依据不同的分类方法,履带车辆转向机构可根据车辆在转向过程中功率流的传递方式分为单功率流转向机构和双功率流转向机构,也可根据在转向过程中两侧履带的运动有无联系而分为独立式转向机构和差速式转向机构。

车辆工程毕业英语翻译

Design Guidelines for Truck Frame Repairability: Benefits and Necessity对于车架的设计指导方针可补救的好处和必要性Jack Ribbens杰克RibbensTech-Cor, Inc.Tech-Cor公司。

Copyright © 2003 SAE International版权©2003 SAE国际ABSTRACT摘要The increase in truck or full frame vehicles in the market has led to unfavorable collision loss experience trends, due in part to the lack of adequate frame repair options. Prior to the incorporation of passive restraints in light duty trucks and sport utility vehicles, frame repair was considered by the vehicle manufacturers and theinsurance industry to be a generally accepted practice.卡车或全帧车辆的增加在市场趋势导致了不利的碰撞损失经验,部分是由于缺乏足够的帧修复选项。

之前的被动约束在轻型卡车和suv,肋骨修复被认为是由汽车制造商和保险行业是一个公认的做法。

With the advent of air bags, forward portions of front frame were redesigned to act as part of the energy management for passive restraint deployment. Several manufacturers weresufficiently concerned with the difficulties of restoring the impact performance of this area of the frame, that they recommended that this area should not be repaired, and furthermore if damaged, the entire frame should be replaced. However, after manufacturers began to adopt Hydro-forming for frame side rails, frame horn and rear frame side rail sectioning sanctioned by some manufacturers has become an accepted repair industry procedure.与安全气囊的出现,提出部分前面框架被设计作为能源管理被动约束部署的一部分。

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