Variable valve train helps enhance the gasoline engine
汽车行业英文词汇翻译
实用标准文档
snip 剪、剪马口铁用剪刀
Snow chains 雪炼
socket wrench 套头扳手
soldering copper 铜头烙铁
soldering lamp 焊灯、焊锡加热灯
Solenoid Valve 电磁阀
solid reamer 固定式绞刀
Solid White Line 实白线
Vehic1e Measurement 汽车丈量
Vehicle 车辆
Vehicle Model 汽车型式
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vehicle identification number (VIN) vehicle-speed sensor
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trailer 房车
Transistor Ignition System Transit
让渡书 transmission (汽车等之) 传动系统；变速器 Tread 轮距 Trunk 行李箱 turbin bleed 涡轮叶片 turbo combined engine 涡轮复合型引擎 turbo unite 涡轮组件 Turn Signal Light 方向灯 turn-signal switch 转向开关 safety goggles 安全护目镜 sand bag 样本瓦斯导入管 sand paper 喷砂清洁器 scanner 锯 screw dies 刮刀 screw gauge 拔栓、螺丝退除器 screw-plate 螺丝模板 Sea1 密封 Seat Belt 安全带 seat cutter （某）座绞刀 Seating
机械工程英语V
机械工程英语V部分V and H check && 锥齿轮啮合的VH检查V belt && V 带V belt tight-up && V 带联组V thread screw && 三角形螺纹V-belt && V带V-belt pulley && V带轮V-belt pulley crankshaft && 曲轴V带轮V-block && V形定位板V-engine && V型发动机V-notch && V形缸口V-pulley && V带轮V-tool && V型刀具VC && (Virtual Channel) 虚拟通道VCA && (Vehicle Certification Agency UK) (英)车辆鉴定机构VCM && (Vehicle Condition Monitoring) 汽车状况监控VCR && (Variable Compression Ratio) 可变压缩比VDI && (Verein Deutsche Industrie Germany) 德国工业协会VEC && (Vehicle Emission Configuration) 汽车排放物结构VF && (Video Frequency) 视频VF presentation && 视频显示，检波显示VFD && (Vacuum Fluorescent Display) 真空荧光屏显示VHVI && (Very High Viscosity Index oils) (油料的)甚高粘度指数VI && (Viscosity Index) 粘度指数VI improver && 粘度改进剂VIM && 可变几何形状进气管VIN && (Vehicle Identification Number) 汽车出厂号码VIP car park && 贵宾停车场VLI && (Vapor Lock Index) 气阻指数VOC && (Volatile Organic Compounds) 挥发性有机化合物VP && 虚拟路径VSE && (Vehicle Standards and Engineering Division) (运输部)汽车标准与工程局VTAC && (Vehicle Type Approval Center) 车型认证中心VTR && (Videotape Recorder) 磁带录像机VTR Cameras && VTR摄影机VVA && (Variable Valve Actuation)可变气门驱动VVT && (Variable Valve Time)可变气门正时VWTA && (Whole Vehicle Type Approval) 车型全面认证Vacuum Light Sources && 真空紫外线光源Vallot helio-thermometer && 瓦劳特日光温度表Venturi && 文丘管，文丘里管Venturi nozzle && 文丘里喷嘴Venturi tube && 文丘里管Vickers hardness && 维氏硬度，维氏硬度Vickers hardness number && 维氏硬度值Vickers hardness penetrator && 维氏硬度压头Vickers hardness tester && 维氏硬度计Volve Long Drain Lubricant Specification && 沃尔沃长换油期润滑油规格[VDS，VDS2]v-belt && V形带vacancy && 空位vacancy chromatography && 空穴色谱法vacuum && 真空，负压vacuum accumulator && 真空贮气筒vacuum advance && 真空点火提前vacuum advance device && 真空提前装置vacuum booster && 真空助力器vacuum booster with master cylinder && 带制动主缸真空助力器vacuum brake && 真空式制动器vacuum carbonitriding && 真空渗碳氮化vacuum carburetor && 真空式化油器vacuum carburizing && 真空渗碳处理vacuum casting steel && 真空浇注钢vacuum controller air conditioner && 空调真空控制器vacuum controller choke && 阻风门真空控制器vacuum controller secondary barrel && 副腔真空控制器vacuum controller valve position && 阀门位置真空控制器vacuum correction && 真空修正vacuum deposition && 真空蒸镀vacuum drying chamber && 真空干燥箱vacuum evaporation chemicals && 真空蒸镀化学药品vacuum evaporator && 真空镀膜台vacuum fluorescent display && 真空萤光显示器，真空荧光显示[VFD]vacuum forming && 真空成形vacuum fusion gas chromatography && 真空熔融气相色谱法vacuum gauge && 真空表，真空规管vacuum hardening && 真空淬火vacuum heat treatment && 真空热处理vacuum hose && 真空软管vacuum melting steel && 真空熔解钢vacuum metallization && 真空金属喷镀vacuum metallizing && 真空金属喷镀vacuum nitriding && 真空氮化vacuum port thermostat && 温控开关真空接口vacuum pump && 真空泵vacuum quenching && 真空淬火vacuum sensor && 真空(负压)传感器vacuum servo && 真空伺服vacuum system && 真空系统vacuum tempering && 真空回火vacuum transducer && 真空(负压)传感器vacuum ultraviolet lasers && 真空紫外线激光vacuum valve && 真空阀vacuum-assisted brake && 真空助力制动器vacuum-over-hydraulic brake && 真空助力液压制动系validation && 校验检验validity check && 有效性检验validity event && 有效事件valley && 谷value && (量)值value analysis && 价値分析value engineering && 价值工程value of a quantity && (量)值value of image shift && 图象漂移量value of scale division && 标度分格值value of scale mark && 标度值value-added network && 增值网络[VAN] values transfer && 量值传递valve && ①阀②气门③阀门valve accelerating pump && 加速泵阀valve beat-in && 气门头，气门沉陷valve block partition disc && 阀体隔盘valve body && 阀体valve bounce && 气门跳动valve cap && ①气门嘴帽②气门室盖valve capacity && 阀容量valve crown && 气门头valve disc && 阀片valve face && 气门工作面valve gate && 阀门浇口valve gear && 气门机构valve guide && 气门导管valve head && 气门头valve lifter && ①气门挺杆②(英)气门拆卸工具valve lock && 气门锁紧螺母valve locking split && 气门锁片valve outlet Mach number && 阀出口马赫数valve overlap && 气门重叠valve plate && 阀板valve plug && 阀芯valve plunger && 气门挺杆valve recession && 气门沉陷valve retainer && 限位板valve rocker && 气阀摇臂valve rotator && 气门旋转机构valve seal && 气门油封valve seat && 气门座，阀座面valve seat insert && 气门镶座valve shaft && 阀轴valve sink && 气门沉陷valve sizing && 阀尺寸计算，阀口径计算valve spring && 气门弹簧valve spring shimmy && 气门弹簧振动，气门弹簧的共振。
Cylinder Deactivation with Mechanically Fully Variable Valve
INTRODUCTIONTo focus the further development of gasoline engines on lower fuel consumption and CO 2-emissions, new technologies for worldwide mass production are required.That is why naturally aspirated engines with large displacement are being progressively substituted by supercharged engines that have both less cylinders and a smaller displacement (Downsizing). They offer decisive fuel consumption advantages particularly for relevant operation points in driving cycles.Another approach achieving reductions in fuel consumption is cylinder deactivation. It is here that the fuel supply is cut off in one part of the engine's cylinders. At the same time, the inlet-and outlet valves are kept closed to avoid pumping losses and to keep the exhaust gas after treatment efficiency. At constant engine torque a BMEP shift of thefired cylinders is provoked and the efficiency of the entire engine is improved.In 1981 General Motors were the first to introduce cylinder deactivation with valve shut down in mass production. Whilst this technology was initially mainly reserved to large displacement engines, it has been utilized in the recent past for the entire engine segment. Amongst such uses are also hybrid engines where cylinder deactivation is also used during coast down to minimize cylinder pumping losses and hence to enlarge the recuperation level.The fully variable valve train offers further efficiency improving measures. Altering the valve stroke as well as valve-opening and closing time allows for advanced load control strategies. In this way pumping losses of the engine can be decisively reduced. The potentials of such fully variable valve trains have been published variously [1], [2],[3], [4]. With Valvetronic, BMW were the first to introduce afully variable valve train in mass production in 2001. Indeed,2012-01-0160Published 04/16/2012Copyright © 2012 SAE Internationaldoi:10.4271/2012-01-0160Cylinder Deactivation with Mechanically Fully Variable ValveTrainRudolf Flierl and Frederic LauerKaiserslautern Technical UniversityMichael BreuerKolbenschmidt Pierburg AGWilhelm HannibalENTEC Consulting GmbHABSTRACTThe targets for future gasoline engines in terms of fuel consumption and exhaust gas emissions require the introduction of advanced technologies to increase engine efficiency.The mechanically fully-variable valve train system UniValve is an effective device to reduce fuel consumption through throttle-free load control. This is achieved by the simultaneous variation of valve lift and valve opening event. The method of cylinder deactivation by closing the gas exchange valves is a further approach to increase the efficiency of combustion engines especially at part load.This paper presents the combination of both techniques on a downsized, turbo charged 4-cylinder DI gasoline engine.The mechanical integration of the valve shut-off capability for cylinder deactivation into the Univalve system is explained and strategies for the transition between 2-cylinder and 4-cylinder modus are discussed. The thermodynamic benefits through adoption of both technologies are analyzed and a reasonable application area of cylinder deactivation in the engine operation map is pointed out. In the conclusion, the achievable fuel consumption benefits will be presented.CITATION: Flierl, R., Lauer, F., Breuer, M. and Hannibal, W., "Cylinder Deactivation with Mechanically Fully Variable Valve Train," SAE Int. J. Engines 5(2):2012, doi:10.4271/2012-01-0160.____________________________________207many other car manufacturers have themselves since followed suit.For the study presented subsequently, the mechanically fully variable valve train system UniValve was chosen.UniValve is able to combine the advantages of cylinder deactivation and dethrottled load reduction, as it has the ability for strong reduction of valve timing towards low lifts,to create zero valve lift and thereby offers the possibility to integrate valve shut off. Beyond this it is possible to include valve lift phasing to increase the residual gas capability of the engine with additional fuel consumption benefits. For system control only low holding and adjusting torques are required.Thus, the thermodynamical potential is not wasted by parasitic losses.DISCUSSIONCYLINDER HEAD CONCEPTThe research results discussed in this paper are based on a 1.6l SI engine equipped with gasoline direct injection and turbo charging. The engine has a cylinder head with two overhead camshafts and 16 valves that are operated through roller finger followers. The engine is equipped with an inlet cam phaser.To accommodate the UniValve-system, the engine's cylinder head is modified on the inlet- and outlet side.A carrier is used here that is fitted on the cylinder head and replaces the conventional valve train with a fully variable valve train on the inlet-and outlet side. Additionally to the inlet side, the outlet side is also equipped with a continuously variable cam phasing system. Both are vane-type, oil drivenactuators controlled by solenoid valves (Figure 1).Figure 1. Cylinder head with CVVL valve train and camphasing on the inlet and exhaust sidesA UniValve system on the inlet side allows for a continuous variation of valve stroke as well as valve timing of all inlet valves. Together with phase adjustment on the inlet side the opening and closing times of the inlet valves can be freely chosen from a broad range what is essential for throttle-free load control. Furthermore, this system accommodates the valve cut-off at cylinders 2 and 3.The UniValve system on the outlet side is designed accordingly. Here the continuous variation of valve timing combined with cam phasing allows improving fuel efficiency at low loads through extending outlet valve timing offering a potential of 3-4%. Additionally, at high loads short outlet valve timing can be realized to maintain the separation of firing order which is essential for high torques. This application of a fully variable valve train actually requires a separate layout allowing valve timings of 110°-140° cam angle at valve lifts between 7 mm and 9 mm [5]. According to the inlet side, UniValve here also allows valve closure on cylinders 2&3.Two actuators that are mirrored mounted to the backside of the cylinder head control the valve lifts by operating the control shafts via a worm gear. Thanks to the system's compact design the base engine's package constrains are met.UNIVALVE-SYSTEMThe UniValve-system is a mechanically fully variable valve train system based on a plane cam mechanism. Its mechanics are based upon a conventional roller finger follower valve train.This system gains its variability through an additional intermediate rocker arm that is introduced between the camshaft and the roller finger follower. This rocker arm features a working lobe, being in contact to the finger follower's roller.Beyond that, the contact to camshaft, circular guide and control shaft is sustained by rollers with needle roller bearings. To secure the contact between all components at alltimes, additional return springs are introduced. (Figure 2)Figure 2. Design of the UniValve CVVL-SystemFlierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012)208The double leg spring maintains the contact between intermediate rocker arm and camshaft whilst the yoke spring lets the rocker arm follow the control shaft.The intermediate rocker arms of two valves are combined into one single rocker arm unit with a common guide roller.This effectively reduces the amount of components and therefore also the system inertia. A further advantage is that each valve pair merely requires one double leg spring and oneyoke spring. (Figure 3)Figure 3. Intermediate rocker arm unitThe adjustment of the desired valve lift is achieved by turning the control shaft which in the simplest case is an eccentric shaft with a circular shape. Through rotating this shaft the area of the working curve engaged effectively is changed. Thus, different valve peak lifts occur combined with different valve events. Figure 4 discloses the function of the system at different positions of the control shaft. In each case the camshaft is shown in the position with the maximumdeflection of the intermediate rocker arm.Figure 4. Variation of valve lift through rotation of thecontrol shaftThe complete travel from maximum down to zero peak lift only requires half a rotation of the control shaft. During this process, the roller of the intermediate rocker arm visits either the top or the lower surface of the control shaft lobe,depending on the direction of rotation.The resulting characteristic of valve lift vs. valve timing strongly depends on the designed UniValve geometry and kinematic layout. Figure 5 shows this relation measured on the prototype cylinder head which was described before during rotation of the control shaft from maximum to zerovalve lift.Figure 5. Valve lift vs. valve timing measured onprototype cylinder headUNIVALVE AND CYLINDER DEACTIVATIONSince only one side of the control shaft is being used for a fully variable adjustment of the valve lift/valve timing, there is the possibility to design alternative characteristics for the adjustment on the second side.This is realized through an adequate design of the control shaft profiles. The shaft is thus either pivoted clockwise or anti-clockwise, depending on which characteristic is going to be applied. This technique can also be used to deactivate the cylinders.Figure 6 contrasts two possible profiles protected for cylinder deactivation. The lower sides of both profiles are identical and allow the parallel variance of all intake valves from maximum peak lift down to zero valve lift. On their upper side the first profile reverses this event. The second profile is modified to stay at zero peak lift for a wider area.Flierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012)209Figure 6. Control shaft profiles for cylinder deactivation When utilizing these profiles in the proposed 4-cylinder engine, both profiles have to be arranged on one common shaft. The first profile controls the valves of cylinder 1 and 4,the second profile is assigned to the valves of cylinder 2 andcylinder 3 (Figure 7).Figure 7. Arrangement of different profiles on thecontrol shaft In the 4-cylinder-mode the valve lift is controlled through the control shaft's upper surface with all valves opening simultaneously. In the 2-cylinder-mode the control shaft's downside is engaged. While the valves on cylinder 2 and 3remain closed in a wide area, peak lift on cylinder 1 and cylinder 4 can be varied in a wide range.As a matter of principle, the control shaft can thus be rotated in both directions. The only precondition is that the control authority can adjust the shaft position without the necessity of additional mechanical stoppers for teaching reasons.DESIGN OF THE VALVE LIFT CHARACTERISTICSBased on the desired characteristics of peak lift versus control shaft angle, the shape of the control shaft results from kinematic reversal. This process is similar to the determination of cam lobes based upon valve lift traces.Particular attention has to be paid here to the geometric feasibility, since sharp transitions in the adjusting characteristics tend to create undercuts in the profile. Figure 8displays the simplest possible design of the control shafts'characteristic.Figure 8. Control shaft characteristic for cylinderdeactivation with single transition band Starting from a control shaft position at 0° (maximum valve lift), all valves are run with the same valve lift when the shaft turns between 0° and −180° (4 cylinder mode).When the control shaft is turned in the direction of positive angle ranges (0° to 180°), a transient area is firstly run through, where the peak lifts of the valves of cylinder 2and 3 are run down to zero valve lift within a very short time.In the subsequent operation area the valves of these cylinders remain closed, whilst the valve lift of the valves on cylinder 1 and 4 can be varied (2-cylinder-mode) to adjust the desired engine load. Based on the limited engine speed and torque in the 2-cylinder mode, the maximum applicable peak lift is suitable to achieve a high volumetric efficiency.The displayed design allows spreading the characteristics for the 2-and 4-cylinder-mode across a very wide angle range of the control shaft. Both modes can be run throttle-free down to engine idling, since the valve lift here can be adjusted down to valve shut off.However, when shifting between the modes the maximum valve lift area is engaged temporarily. Without countermeasures, this would increase the cylinder charge and hence the engine load. To achieve smooth transition torque compensation is required, preferentially via throttle flap and cam phaser position, but also via retarded spark.Turning the control shaft through the zero valve lift area (directly from 180° to −180°) at increasing load requirementsFlierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012)210is not possible, since all valves would then temporarily remain closed and the engine could thus not produce torque.To address this, Figure 9 shows an alternative control shaftcharacteristic.Figure 9. Control shaft characteristic for cylinder deactivation with valve lift phasing and two transitionbands Starting at a control shaft position of 0° (maximum valve lift) the engine can be run in 4-cylinder mode when,analogous to the layout design shown in Figure 8, the control shaft is rotated into the range of negative angle values.By turning the control shaft into positive angle ranges, it is likewise a transient area that is firstly run through until the engine is subsequently run in 2-cylinder operation mode. In contrast to the layout design demonstrated in Figure 8, the 4-cylinder mode keeps a minimum valve lift (here for example 1mm) maintaining a certain engine load. Thus, by turning the control shaft across the minimum valve lift range, the 4-cylinder mode can be shifted into a 2-cylinder-mode without engine stall. Hence, the advantage of this layout design is that a second possibility to switch between 2-cylinder and 4-cylinder mode is available. Precondition to make use of this control shaft travel is, that the transition coincidents with a low torque request, e.g. during coast down. As the control shaft requires a very small rotation angle only, a very fast response is realized.These transient advantages come to the expense of high idle fuel consumption. Caused by the ever present minimum peak lift in the 4-cylinder mode, the engine must be throttled slightly towards idle.Figure 9 additionally shows the possibility to equip one valve pair with valve lift phasing, being active at lower and medium peak lifts. By lift phasing, the intake valves of one cylinder are opened along different traces, thus introducing a swirl motion. This measure improves the residual gas capability of the combustion process which, especially in the case of lower and medium load, helps to lower the specific fuel consumption. In map points with large peak lifts, a merge into parallel valve lift mode takes place, ensuring the full breathing capacity and full load capability of the engine.FRICTION LOSSES IN VALVE TRAINRuns at the motored test rig confirm the valve trains'flawless mechanics and maturity. In fully variable valve trains the frictions losses occurring in the valve train demand particular attention due to the increased amount of contact partners. Figure 10 shows the measured average drag torque of the intake cam at different peak lifts. Added in red is the friction of the engine's original roller finger follower valvetrain.Figure 10. Mean drag torque of UniValve compared toRFF valve train The diagram shows that the drag torque with UniValve is on the same or even lower level than that of a conventional valve train. Moreover, most frequently the engine is run at low speeds and loads. Figure 10 demonstrates, that for low peak lifts even less friction losses are observed due to the reduced spring load introduced here. For example, an engine mapping point of n = 2000 min −1, BMEP = 3 bar can be obtained with a valve lift of 2 mm. Here, the valve train friction is strongly reduced compared to the basis valve train.The low friction level achieved results from a sophisticated optimization of the entire valve train. Among these optimizing measures is a reduced diameter of the camshaft bearings, reduced cam perimeter as well as the usage of rollers with needle bearings at all contacts.Moreover, due to lightweight design, a reduction of the system inertia and thus also of the required spring forces was achieved. In summary, no increase in valve train friction has to be expected when using fully variable valve trains.RESULTS ON FIRED ENGINEThe efficiency of the measures taken on the engine's fuel consumption has been undoubtedly proved at engine dynamometer testing. Figure 11 compares cylinder pressure traces for 4-cylinder and 2-cylinder mode at n = 2000 min −1,BMEP = 2 bar, both with throttle-free load control.Flierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012)211Figure 11. Comparison of cylinder pressure between fullengine and half engine operation mode In cylinder deactivation mode the combustion chambers of the deactivated cylinders 2 & 3 are kept shut by the closed valves. As result the enclosed air works like a pneumatic spring which is periodically compressed and decompressed without overall pumping work. Consequently the parasitic losses of the dragged cylinders are reduced to the level of their friction losses.In order to keep the engine load constant and to compensate the friction losses of the unfired cylinders, the load of the remaining cylinders must be elevated. Thus, the effective compression ratio of the active cylinders increases and the thermal efficiency is considerably improved. This translates to reduced fuel consumption.Additionally, slight advantages in pumping work result on these cylinders. Figure 12 likewise compares the low pressure loop of throttled and throttle-free full engine mode with that of the throttle-free half engine mode at n = 2000 min −1,BMEP = 2 bar. The highlighted areas indicate the pumpingmean effective pressure.Figure 12. Comparison of charge change cycleIn comparison to the base engine which is run in throttled mode (blue area), the gas exchange work can already be reduced sharply by utilizing UniValve (red area). The remaining losses are due to the flow losses at small valve lifts, which are required to meet the low engine load. After inlet valve closing, an expansion and recompression ensues on a similar level, hence does not contribute to the pumping work.The same situation applies also for the 2-cylinder-mode (orange area). However, the load required for the fired cylinders is more than doubled, and the valve opening duration has to be expanded. This is hence accompanied by a greater peak lift what results in lower throttle losses at the valves. Hereby the thermodynamical advantage in deactivation mode is extended by gas exchange improvements.Tests in the engine operation map illustrate the efficiency of these mentioned technologies. The comparison covers an engine speed range between 1000 min −1 and 4000 min −1 at mean break pressures up to BMEP = 7 bar, which is also feasible for 2-cylinder mode. Figure 13 shows the difference in break specific fuel consumption between the 2-cylinder and 4-cylinder engine mode. The engine was run throttle-free in both cases. Load control is exercised via controlling the valve lift/valve timing at fully opened throttle valve. Negativetest results indicate fuel savings in the 2-cylinder mode.Figure 13. Difference of fuel consumption in 2-cylinder-modus to 4-cylinder-modus [g/kWh] (both throttle-free)It is noticeable that cylinder deactivation generates considerable advantages in fuel consumption for engine loads up to BMEP = 5 bar. The uppermost reductions can be achieved close to engine idle. The reasons for this impressive advantage were given before.At higher engine loads, the high cylinder pressures in the fired cylinders tend to provoke knock. Hence, spark advance has to be retarded, and the optimal combustion timing can no longer be obtained. This disadvantage of the 2-cylinder modeFlierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012)212coincidents with the improving load conditions in full engine mode and ends up in a fuel penalty. With increasing engine speeds, the limit shifts slightly towards higher engine loads due to the decreasing knocking tendency.In addition, Figure 13 displays a possible application area for cylinder deactivation (red line). At lower engine speeds the increased crank angle deviation - occurring due to the 2-cylinder mode - results in such strong engine vibrations that this range without additional measures has to be excluded from the cylinder deactivation mode. The greater the engine speeds, the more this limit shifts toward higher loads. As a matter of fact, it therefore also makes sense to run idle in 4-cylinder mode.The displayed upper engine speed of 4000 min−1 does not describe here the mechanical limit of the cylinder deactivation mode. Rather, it marks as a reasonable limit for customer driving operation.The maximum load applicable in the 2-cylinder modus is lower than the limit suggested by the best BSFC trace. Reason for that is that a certain torque reserve is needed to temporarily cover the additional losses during mode change. When the fuel injection on cylinder 2 & 3 is cut off, but the intake valves are still open, additional pumping losses are provoked. This increased load demand has to be compensated by the fired cylinders 1 & 4. The necessary torque reserve is only obtainable up to certain engine loads which therefore mark the upper limit of the 2-cylinder mode. This is particularly relevant when considering that the turbo chargers' boost pressure cannot be used during transition because of the system's high inertia.It is furthermore advisable to provide hysteresis when applying the cylinder deactivation to avoid shifting back and forth frequently.TRANSITION BETWEEN 4-CYLINDER AND 2-CYLINDER MODUSThe UniValve system with cylinder deactivation offers particular advantages when shifting between 4-cylinder and 2-cylinder mode. Since conventional valve lift switching systems like switchable tappets or lash adjusters only have the ability to engage and disengage the valves discretely from one cycle to the next, they have to compensate the occurring transient torque steps excessively and fast. Basically, spark excursions are responding fast enough, but to the expense of fuel penalties. In the case of the system discussed here this problematic is defused.When switching from 4-cylinder to 2-cylinder mode, the inlet valve lift is continuously changed by the rotation of the control shaft from the throttle-free to the switching operation point.At the switching point all parameters for the 2-cylinder modes are held available, so that after cutting the fuel injection the 2-cylinder mode is directly present. Afterwards, the outlet and inlet valves of cylinder 2 & 3 get closed and the valve lift of the respective inlet valves on cylinder 1 & 4is further adjusted to a throttle-free operating point in the 2-cylinder mode (Figure 14).Figure 14. Operation points in the control shaftcharacteristics during operation mode transitionWhen generating cylinder deactivation by switchable valve train components elements like tappets, roller finger followers or lash adjusters, the switching has to be specifically effected in the cam lobe's base-circle-phase. The required time here limits the maximum possible engine speed for switching. When using UniValve for mode switching, the system is independent from engine speed. In detail, during the mode transition the system runs through various intermediate lifts, which are designed for the engine's cut off speed.One of several possible strategies for a smooth mode transition ensuring a high drivability is displayed in Figure 15. Switching from full engine mode into cylinder deactivation mode is exemplified here at a constant load point of n = 2000 min−1, BMEP = 4.5 bar. The engine was run with control shafts on the inlet and outlet side which were both designed according to Figure 14/Figure 8.Flierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012)213Figure 15. Engine control during cylinder deactivationmode transitionThe switching starts in a throttle-free 4-cylinder mode. When rotating the control shaft in direction of increasingly higher peak lifts, the throttle body has to be closed in order to compensate the additional load. Due to the similar response time of control shaft and throttle body, any load step is avoided. The spark timing is adjusted for maximum break torque. Closing the throttle body changes the manifold absolute pressure. Together with the elevated valve lift and overlap area the pressure delta increases the residual gas fraction, requiring advanced spark timing.Already before reaching the actual point in which the fuel injection on cylinder 2 and 3 is cut off, the throttle body is opened again and the additional load is compensated for a short time by spark retardation. In this way, when cutting-off the fuel injection on cylinders 2 and 3, the ignition angle can simultaneously be advanced to maintain a constant torque level. In so doing, the additional load also can be provided as required due to the pumping work of the still opened valves of the unfired cylinders. This blow through of air appears on the lambda sensor as lean mixture. However, as the peak lifts are rapidly cut down on cylinder 2 & 3, the AFR excursion is small. In addition, cylinder 1 & 4 can be run rich simultaneously. This lowers the AFR excursion further on, increases the NMEP output of the active cylinders and helps to reduce their NOx raw emission output while the catalytic converter is struggling with excessive oxygen.Subsequently, the outlet valves are firstly closed followed by the inlet valves. Torque is again compensated with the help of the throttle body. Finally, the control shaft on the inlet side is adjusted again for throttle-free operation where the throttle body is completely opened.In this entire transition process the inlet cam phaser is used to optimize the fuel consumption and to stabilize the combustion. The speed of the switching process is determined by the speed of the control shaft. Thanks to a high-performance actuator, at an engine speed of n = 2000 min−1the transition procedure only takes 10 engine revolutions.The process is also realizable in the opposite direction. Here, also different strategies exist depending on the sequence of de- and reactivating the valves.SUMMARY/CONCLUSIONS The UniValve-System is an effective and mature technology to significantly reduce the fuel consumption of stoichiometric SI engines by throttle free load control. At the same time, it intrinsically offers the possibility for cylinder deactivation without any additional costs. By combining cylinder deactivation with throttle-free load control in a 4-cylinder engine, the great potential of UniValve can be demonstrated. Exemplarily, Figure 16 shows these consumption advantages in two cycle relevant engine operation points.Flierl et al / SAE Int. J. Engines / Volume 5, Issue 2(May 2012) 214。
丰田高原进气补偿原理
丰田高原进气补偿原理The Toyota highlander intake compensation principle is an important aspect of how the vehicle's engine functions. 进气补偿原理是丰田高原引擎功能的重要组成部分。
It plays a crucial role in ensuring the engine performs optimally in varying driving conditions. 它在确保引擎在不同的驾驶条件下能够最佳地运行方面发挥着至关重要的作用。
The intake compensation system is designed to adjust the flow of air and fuel into the engine to maintain an ideal air-fuel ratio. 进气补偿系统旨在调整空气和燃料进入引擎的流量，以保持理想的空燃比。
This helps to improve fuel efficiency, reduce emissions, and enhance overall engine performance. 这有助于提高燃油效率，减少排放，并增强整体引擎性能。
Understanding the principles behind this system can provide insight into how modern vehicles are designed to operate efficiently and responsibly. 了解这一系统背后的原理可以深入了解现代汽车如何被设计成能够高效和负责地运行。
The intake compensation principle is based on the concept of constant volume combustion. 进气补偿原理基于恒定体积燃烧的概念。
新款洪大豪华车辆—Accent豪华版详细介绍说明书
AccentHyundai Motor Company GEN. LHD 1708 ENG. WDCopyright © 2017 Hyundai Motor Company. All Rights Reserved.Dealer stampwanted.The all-new AccentAccent is big on style and featuresThe all-new Accent gives you everything you have ever wanted in a family car-and muchmore. The style is strong and confident, equal to the best in the business. Inside, Accent issurprisingly spacious and offers loads of cargo space, handy for those long trips. And whenit comes to performance and safety, Accent checks all the boxes, leaving nothing to bedesired. Accent: It's the start of a great journey.Projection headlamps with LED position & DRL lamps17˝Alloy wheelsFog lampsLED rear combination lamps The beauty is in the details.Take the ordinary and transform it into the extraordinary: That’s the beauty of Accent.The latest LED and projection technologies have been applied to the front lighting package to maximizevisibility. Chrome detailing on the front grille and around the fog lamps take Accent to a higher level.Steering wheel includes remote control functions for audio,cruise control and BluetoothAutomatic climate control5.0˝ Multimedia displayConnectivity (USB/AUX)Simply set the desired temperature and the powerfulblower provides air conditioning, heating and ventilation tokeep you perfectly comfortable regardless of the outsideweather conditions.Multi-function LCD provides backup camera image, time/date, MP3 player status, AM/FM radio tuning and Bluetoothconnectivity for mobile phone and personal audio devices.Connect smart devices and enjoy them through the Accent'sspeaker system. 12V power outlet and lighter included. Feel the emotional connection.It just feels right. From the moment you step inside, the touch points and visual cues look and feel familiar. Everythingoperates intuitively like you would expect. That’s a mark of good design. Materials have been carefully selected for theiraesthetic qualities but at the same time meet the highest durability standards.Gamma 1.6 MPi Gasoline Kappa 1.4 MPi Gasoline 12199HP/6,300rpmHP/6,000rpm15.413.5kg.m/4,850rpmkg.m/4,000rpmDiscover the freedom of the open road with Accent.Accent’s 1.6 liter Gamma engine is one of Hyundai’s most remarkable powerplants, acclaimed for itsefficient and reliable design. Mated to a 6-speed transmission and incorporating a dual overhead camwith variable valve timing, it purrs like a kitten to deliver pure driving pleasure. Push button start and acentral gauge cluster with Supervision display technology further elevate the Accent driving experience.Push-button start / Smart key6-speed automatic transmission Supervision cluster6-speed manual transmissionThe smart key ends the search for the keyhole! Includes push button start, speed sensing automatic door locks, remote lock/unlock for the doors and trunk plus a burglar alarm.You will hardly notice this 6-speed gearbox doing its work. Automatic shifting is quick, smooth and quiet but also very convenient. Its efficient design helps maximize fuel economy.The Supervision cluster, with its circular rev counter and speedometer, features white backlighting for razor-sharp clarity and readability. Includes an integrated 3.5-in monochrome display with trip computer, refueling calculator and oil change reminder.For drivers who put economy above all else, the 6-speed manual is the perfect choice. Clutch operation is easy and predictable and as you shift through the gates, there's a nice, precise feel.Safe and secure.Accent’s super-strong body structure offers unparalleled protection. Critical areas are reinforced with ultra high-tensile strength steel so that Accent meets the very latest crash safety standards of the National Highway Traffic and Safety Administration of the United States. Six airbags and the Anti-locking Brake System with Electronic Stability Control means you will be well-prepared in case the worst should happen.6-airbag systemHillstart Assist Control6-airbags provide all-round protection. One each for the driver and front-seat passenger, two curtain airbags running the length of the cabin, plus two side curtain airbags.Rearview cameraThis simple system erases all doubt about who or what is behind you when backing up. Graphic overlay serves as a parking aid to help avoid scrapes and scratches.Stopping and starting on very steep road can be stressful and potentially dangerous. HAC prevents the car from accidentally rolling backward whenever the brake pedal is released on a hill.FeaturesCascade grille in chrome and black finish The uniquely shaped cascade grille is a Hyundai design signature that declares membership in the Hyundai family.Chromed door handlesThey add a small touch of luxury and are pleasantly eyecatching. Included with the SmartKey option package.High-mounted stop lampThe high mounted stop lamp is located on the rear parcel tray for easy bulb changes whenever required.Sunglass caseA handy place for safely storing your pair of pricey sunglasses or any other odds and ends.Side mirrors with built-in LED indicator lamps Side mirrors feature heating elements, electric folding and built-in LED turn indicator lamps for greater safety and convenience.Premium chrome moldingA light touch of chrome along the belt-lineamplifies the radiance factor. The chrome finish is much easier to maintain mirror chrome.Luggage spaceFlat-folding 60:40-split rear seatsAccent's versatility is surprising: It can handle a mix of passenger and cargo hauling duties thanks to the flat-folding rear seats.Driver seat height adjusterAdjusting the height of the seat cushion could not be easier or more intuitive with this lever which features a simple and sturdy design.Sliding armrestThe center console armrest cover moves forward to enhance your comfort.Rheostat & Electronic Stability Control OFF switch Controls the illumination level of the central gauge cluster to suit your personal preferences. The ESC OFF hands control back to you.Smart trunkStand close to the trunk and in three seconds the lid opens automatically without pressing any key button. The smart trunk feature iseasily deactivated at any time.The trunk offers an impressive 387 liters (SAE) of storage space and if that's not enough, the rear seats can be folded down for even more room.A full-size spare tire is included.Exterior colorsInterior colorsClear white (UD)Woven blackGLAzure blue (B2R)Aurora black (ABP)Snow white pearl (SWP)Woven grayUrban gray (U4G)Silky silver (4SS)Woven beige Woven black GLSWoven gray Woven beige Leather black GLS optionLeather gray Leather beigeSunset orange (SN4)Ice wine (W4Y)Fiery red (R4R)15˝wheels cover 15˝alloy wheels17˝alloy wheelsLeather orange brownWoven+Leather limeWoven+Leather redOverall width Wheel tread1,7291,522Wheel tread1,529Overall height1,4754,3852,580Overall length Wheel baseUnit : mmSpecifications● The above values are results from internal testing and are subject to change after validation.● Some of the equipment illustrated or described in this catalog may not be supplied as standard equipment and may be available at extra cost.● Hyundai Motor Company reserves the right to change specifications and equipment without prior notice. ● The color plates shown may vary slightly from the actual colors due to the limitations of the printing process.●Please consult your dealer for full information and availability on colors and trims.。
vvt发动机的作用,组成及工作原理
vvt发动机的作用,组成及工作原理英文版The Role, Composition, and Working Principle of VVT Engine The VVT (Variable Valve Timing) engine is a type of internal combustion engine that offers improved fuel efficiency and power output by adjusting the timing of the intake and exhaust valves. This article will explore the role, composition, and working principle of the VVT engine.Role of the VVT EngineThe primary role of the VVT engine is to enhance the performance and efficiency of the internal combustion process. By adjusting the timing of the intake and exhaust valves, the VVT engine can optimize the flow of air and fuel into the cylinders, improving combustion and power output. This results in better fuel economy, lower emissions, and smoother engine operation.Composition of the VVT EngineThe VVT engine is composed of several key components, including the cylinder head, intake and exhaust valves, camshaft, and VVT control system. The cylinder head houses the intake and exhaust valves, which control the flow of air and fuel into and out of the cylinders. The camshaft is responsible for opening and closing these valves, and the VVT control system adjusts the timing of the camshaft to optimize valve operation.Working Principle of the VVT EngineThe working principle of the VVT engine is based on the adjustment of camshaft timing. The VVT control system uses sensors to monitor engine speed, load, and other parameters. Based on these inputs, the control system calculates the optimal timing for the intake and exhaust valves to open and close. It then adjusts the camshaft timing accordingly, using a mechanism that can vary the position of the camshaft relative to the crankshaft.By adjusting the camshaft timing, the VVT engine can optimize the flow of air and fuel into the cylinders. Thisimproves combustion efficiency, resulting in higher power output and better fuel economy. Additionally, the VVT engine can also adjust the timing to reduce emissions and improve engine smoothness under different driving conditions.In conclusion, the VVT engine plays a crucial role in enhancing the performance and efficiency of internal combustion engines. By adjusting the timing of the intake and exhaust valves, it optimizes the flow of air and fuel, improving combustion and power output. The composition of the VVT engine includes the cylinder head, intake and exhaust valves, camshaft, and VVT control system. The working principle is based on the adjustment of camshaft timing, allowing the engine to adapt to different driving conditions and achieve optimal performance.中文版VVT发动机的作用、组成及工作原理VVT（可变气门正时）发动机是一种通过调整进气和排气门正时来提高燃油效率和功率输出的内燃机。
基于GT-POWER的可变气门升程发动机模拟开发及优化匹配
• 16•内燃机与配件基于GT-POWER的可变气门升程发动机模拟开发及优化匹配Simulation Development and Optimization Matching of Engine with Variable Valve LiftBased on GT-POWER周世平ZHOU Shi-ping(一汽海马动力有限公司）(FAW Haima Engine Co.,Ltd.)摘要：本文首先分析可变气门升程发动机的原理及特点，其后根据我司某自然吸气发动机的试验数据建立GT-POW ER仿真模 型进行并进行校核，然后基于可变气门升程的原理对该发动机模型进行了修改，并计算了不同工况下的最佳升程及气门正时。
最终结 果表明，在达到动力性能目标的前提下，中低转速的燃油消耗率较原机得到了较好改善，初步达到了改进的预期效果。
Abstract:Firstly,the characteristics and principles of Variable Valve Lift have been analyzed,Secondly,a naturally aspirated engine simulation model with Haima Motor has been calibrated based on GT-POWER.Then this model have been modified according to the Variable Valve Lift principle.Finally,The results show，that the VVL engine reach the target of its dynamic and economic performance.In low speed,the fuel consumption rate has been reduced well,and the output power which achieved the expected effect of the improvement basically.关键词：可变气门升程;优化;VVL ;GT-POWERKey words:Variable Valve Lift；optimization；VVL；GT-POWER1概述“节能-减排”是当今社会发展的两大主题。
汽车英语 Engine(2.5)
所以在气门传动机构中要预留一些间隙使气 门得以完全关闭。这就是说， 门得以完全关闭。这就是说，气门传动机构 运动要与气门有一个充分远的距离， 运动要与气门有一个充分远的距离，使得气 门在气门弹簧作用下紧闭气门座。 门在气门弹簧作用下紧闭气门座。可是如果 间隙过大，会引起轻微的金属敲打声。 间隙过大，会引起轻微的金属敲打声。
当发动机在压缩冲程和作功冲程工作时， 当发动机在压缩冲程和作功冲程工作时，气门必须紧贴在气门 座上，形成良好的气密性以防止燃烧室漏气。 座上，形成良好的气密性以防止燃烧室漏气。如果气门关闭不 发动机就不能发挥出全部的功率。 严，发动机就不能发挥出全部的功率。而且气门头部容易被经 过的高温气体烧蚀， 过的高温气体烧蚀，活塞顶部也可能会碰到气门使发动机严重 损坏。 损坏。
由上显而易见，排气门在进气门打开的一小段时间内也打开着。换 由上显而易见，排气门在进气门打开的一小段时间内也打开着。 句话说，排气冲程终了和进气冲程初期有一小段时间的重叠， 句话说，排气冲程终了和进气冲程初期有一小段时间的重叠，这称 为气门重叠。不同的发动机，其配气相位和气门重叠是不一样的。 为气门重叠。不同的发动机，其配气相位和气门重叠是不一样的。
SEA—Special English for Automobile
CHAPTER２
internal combustion engine
Valve clearance:
When the engine runs in compression stroke and power stroke, the valves must close tightly on their seats to produce a gas-tight seal and thus prevent the gases escaping from the combustion chamber. If the valves do not close fully the engine will not develop full power. Also the valve heads will be liable to be burnt by the passing hot gases, and there is the likelihood of the piston crown touching an open valve, which can seriously damage the engine.
汽车专业英语题库
2021-2021-2汽车专业英语题库一、单项选择题1.What do almost all cars use to convert gasoline into motion? DA. one-stroke combustion cycleB. two-stroke combustion cycleC. three-stroke combustion cycleD. four-stroke combustion cycle2. A car engine ’s job is to B .A. convert fuel into heartB. convert fuel into motionC. convert fuel into exhaust3. A car uses a four-stroke engine. The four strokes are A .A. intake, compression, ignition and exhaustB. injection, rotation, ignition and exhaustC. injection, carburetion, rotation and exhaust4.With the A at the bottom of the cylinder, the exhaust valve opens to allow theburned exhaust gas to be expelled to the exhaust system.A. pistonB. valveC. camshaftD.crankshaft5.According to the method of ignition of the air-fuel mixture, engines are divided into B .A. gas engine and steam engineB. gasoline engine and diesel engineC. external combustion engine and compression ignition engineD. internal combustion engine and diesel engine6.What is the core of a car ’s engine? AA. The cylinderB. The spark plugC. Windshield-washer fluidD.Exhaust7.Which statement about cylinder head is fault? BA. The cylinder head is bolted to a very flat surface above the cylinder portion of the block.B. The cylinder head is cast into one piece from iron only.C. The cylinder head forms the upper portion of the combustion chamber.D. The cylinder head is used to hold the valves, and it has ports to allow air, fuel and exhaust tomove through the engine.8. The crankshaft and connecting rod converts A energy into energy usedto drive the vehicle.A. thermal, mechanicalB. mechanical, thermalC. kinetic, mechanicalD. mechanical, kinetic9. What causes a car to burn and lose oil? DA. Lack of gasB. Radiator troubleC. A failing exhaust systemD. An old engine with piston rings that no longer seal the cylinder and piston properly.10.What is the heart of the lubrication system, which is located in the oil pan on the bottomof the engine? And it pulls oil up from the oil pan and makes the engine oil circulate throughthe engine. CA. Screened intakeB. oil filterC. oil pumpD.oil pressure relief valve11.Which statement about the Lubrication oil is fault? CA. The oil forms a film on the metal surface and prevents a metal to metal contact.B. The oil absorbs and carries the heat away from the engine components.C. The oil washes off dirt away from the engine parts through its chemistry.D.The oil forms a good seal between piston rings and cylinder walls.12.What is the cooling agent in the liquid cooling system? A系部： 班级： 学号： 姓名：A. CoolantB. AirC. LubricationD.Gasoline13.What is it apparatus that cools the motor? AA. RadiatorB. ThermostatC. CoolantD.Pump14. To avoid loss of antifreeze due to expansion, the cooling system A .A. must not be completely filledB. must install a bypass valveC. must install a pressure control valveD. must be sealed15.The primary role of the distributor is to distribute high voltage from the C to the correct cylinder.A. Spark plugB. pistonC. coil16. Spark timing is so critical to an engine’s performance that most modern cars use a sensor to tell the engine control unit(ECU) B .A. the exact temperature of the spark plugs.B. the exact position of the pistons.C. the exact location of the coil.17. When you turn the key to a car, the starter motor will C .A. send electricity to the spark plugs, then start the ignition system.B. send electricity to the fuel pump, then force the car to start.C. spin the engine a few revolutions, then start the combustion process.18.The amount of force the clutch can hold depends on the B between the clutch plate and the flywheel , and how much force the spring puts on the pressure plate.A. distanceB. frictionC. relationship19. What is the most common problem associated with clutches? BA. The friction material on the disk makes a whining noise.B. The friction material on the disk wears out.C. The friction material on the disk lasts too long.20. A manual transmission is connected to the engine through the C .A. differentialB. beltC. clutch21.A latch mechanism is inserted into the slot in the output shaft in the manual transmission, so as to lock the drive wheels and keep them from turning, thereby preventing the vehicle from rolling. Which gear does the statement indicate? BA. The fifth gearB. The parkingC. The neutralD.The reverse22. How faster should a car with a CVT reach 60 mph(97kph) than the same car with the same engine and a manual transmission? BA. 10 percentB. 25 percentC.40 percent23.Which of the following is one of the jobs of the differential? CA. To allow the wheels to rotate at exactly the same speed.B. To maintain torque.C. To aim the engine power at the wheels.24. The drive shaft connects A to .A. the transmission output; the differential pinion shaftB. the cylinder; the clutchC. the transmission input; the differential pinion shaftD. the clutch; the transmission output25. What are the two main types of steering systems that cars use? DA. Recirculating-ball and power-assisted.B. Rack-and-pinion and power-assisted.C. Power-assisted and active steering.D. Recirculating-ball and rack-and-pinion.26.What is the function of a backing plate? AA. To hold the braking system together.B. To control the flow of brake fluid.C. To control the brake pads.27. A is a computer-controlled brake system that helps prevent wheel lockup during braking.A. ABSB. ITSC.GPSD.EBCM28.The three process involved in the ABS working process are as follows: AA. Pressure increases cycle, pressure maintains cycle, pressure reduces cycle.B. Pressure maintains cycle, pressure increases cycle, pressure reduces cycle.C. Pressure reduces cycle, pressure maintains cycle, pressure increases cycle.D. Pressure maintains cycle, pressure reduces cycle, pressure increases cycle.29. What does MSRP stand for ? BA. Manufacturer suggested rate plan.B. Manufacturer suggested retail price.C. Manufacturer suggested ranking place.30.What does APR stand for? AA. Annual percentage rate.B.Average pinciple rate.C.Annual primary rate.31. The D converts the rotation motion of the steering wheel into the straight-line motion.A. drag linkB. tie rodC. Steering knuckleD. Steering gear二、词组互译1.火花塞spark plug2.燃油滤清器fuel filter3. 限压阀oil pressure relief valve4.机油泵oil pump5. 空挡平安开关neutral safety switch6．传动系统drive line/drive train/power train7.离合器主缸master cylinder8.别离轴承release bearing9.液压hydraulic pressure10.万向传动装置universal joint gear11.驱动桥driving axle12.半轴half shaft13.主减速器final drive14.驱动齿轮pinion gear15.齿条齿轮转向器rack-and-pinion16.循环球转向器recirculating ball17.转向盘steering wheel18.蜗轮worm gear19.盘式制动disk brake20.鼓式制动drum brake21.紧急制动emergency braking22.交流电alternating current23.备件spare part24.售后效劳after-sales service25.汽车机电维修部auto electrical and mechanical maintenance department26.贸易Trade Co.,LTD27.机电技师electrical technician28.特许经销商permit specially a dealer29.四轮定位foul-wheel alignment30.预付定金down payment31.性价比cost performance32.信用卡credit card33.电动机electric motor34.汽油机gasoline engine35.曲柄连杆机构crankshaft and connecting rod assembly36.配气机构valve train37.压缩比compression ratio38.热能thermal energy39.机械能mechanical energy40.仪表dash panel insert三、写出汽车英语缩写对应的英语全称并翻译成汉语1.ICE internal combustion engine 内燃机2.TDC top dead center 上止点3.BDC bottom dead center 下止点4.ACL air cleaner 空气滤清器5.ALT alternator交流发电机6.GND ground 接地7.EFI electronic fuel injection 电子燃油喷射8.ECU electronic control unit 电控单元9.MT manual transmission 手动变速器10.AT automatic transmission 自动变速器11.RPM revolutions per minute 每分钟转数12.CVT continuously variable transmission 无极变速器13.CVJ constant velocity joint 等速万向节14.SS steering system转向系统15.ABS anti-lock braking system防抱死制动系统16.SD sales department销售部门17.FAW first automotive works 第一汽车制造厂18.SUV sports utility vehicle 运动型多功能用车四、句子翻译1.As we know, the engine is the heart of a vehicle, and it can produce great power to propel thevehicle. Generally speaking, an engine contains one engine block, two assemblies and five systems.2.The amount that the mixture is compressed is determined by the compression ratio of theengine. The compression ratio on the average engine is in the range of 8:1 to 10:1.3.The engine crankshaft and connecting rod assembly is to convert thermal energy intomechanical energy used to drive the vehicle. And it is composed of pistons, piston rings,connecting rods and crankshafts.4.Five systems mean the fuel supply system, the lubrication system, the cooling system, theignition system and the starting system.5.At that time, the drive members connected to the transmission input shaft are either stationaryor rotating at a speed that is slower than the driving members connected to the enginecrankshaft.6.Differentials are typically composed of a gear mechanism in which a ring gear receive inputpower, which is transferred to two side gears by means of usually two opposing central pinion gears on a common shaft.7.The EFI has job of supplying a combustible mixture of air and fuel to the engine. In order toget a cleaner emission ,electronic fuel injection system is applied. This system can be divided into three: fuel delivery system , air induction system, and the electronic control system.8.The cooling system forms an instrinsic part of an automobile engine. Ideally,The automobilecooling system keeps the engine running at an optimum temperature whatever the operating conditions are.9.The starting system is to start the engine. This system is composed of battery, ignition switch,starter motor, starter solenoid, starter drive, cables and wires.10.The drive line or drive train transfers the power of the engine to the wheels. The drive trainconsists of the parts from the back of the flywheel to the wheels, including the clutch, the transmission, the drive shaft, the universal joint, the differential, the final drive and the half axle.11.The transmission is used for changing the torque transmitted from the engine crankshaft to thepropeller shaft, reversing the vehicle movement, and disengaging the engine from the drive line for a long time at parking or coasting.12..Although the hardware used in an ABS varies with each manufacturer , the system mainlyconsists of an electronic control unit, a hydraulic actuator , and wheel speed sensors at each wheel.13.The first 4S automobile store was established by the authorization of the automobilemanufactures and market in 1998,and it has unified appearance, unified logo, unifiedmanagement and service standards that operate only a single auto brand.14.Generally speaking, we can give you 3% discount about this car . This month we willpopularize the type of car ty reducing 10%, so this is really a bargain.15.When we step on the brake pedal, we are actually pushing against a plunger in the mastercylinder, which forces hydraulic oil through a series of tubes and hoses to the braking unit at each wheel.。
内燃机气门正时的新发展——机械式FVVT技术
内燃机气门正时的新内燃机气门正时的新发展发展发展——————机械式机械式FVVT 技术朱譞晟上海市闵行区颛兴路，201108成稿日期：2011-09-05概述概述::本文介绍一种以纯粹机械的方式构建的一种连续可变气门驱动机构，通过对一对摆杆摆动的角度和初始位置的控制，构成一个变速摆系统，并实现气门的持续开启时间的连续可调，且同时保持气门升程不变。
此技术称作机械式FVVT（全可变气门正时）技术。
关键字关键字::内燃机，全可变气门正时，变速摆T he N ew D evelopment of Internal combustion Engine V alveT iming -Mechanical FVVT TechnologyZhu XuanshengZhuanxing Road,Minhang District,Shanghai 201108Abstract :This paper describes a purely mechanical way to build a continuous variable valve drive mechanism,through a pair of swing of the pendulum angle and the initial position of control to form a variable speed pendulum system,and to achieve continuous valve open time continuously adjustable,while maintaining the same valve lift.This technique is called Mechanical FVVT (Fully Variable Valve Timing)technology.Keywords :Internal combustion engine,Fully Variable Valve Timing,variable speed pendulum1.1.前言前言内燃机气门正时的历史由来已久，但目前尚未达到极限的优化。
Variable lift valve train
专利名称：Variable lift valve train 发明人：Albert B. Dewey, III申请号：US07/520550申请日：19900508公开号：US04986227A公开日：19910122专利内容由知识产权出版社提供摘要：A variable lift valve train mechanism for an internal combustion engine. The valve train varies valve lift depending on engine RPM, providing a relatively lower valve lift at lower engine RPMs for increased bottom-end torque and a relatively higher valve lift at higher engine RPMs for increased overall top-end performance. The valve train includes a rocker arm at one end engaging a valve and at its other end engaging a cam such that upward movement of the cam causes downward opening movement of the valve. The rocker arm has a convex fulcrum- engaging upper surface extending between the rocker arm ends. A variable- position fulcrum assembly includes a pivot arm, the lower end of which is pivotally mounted to a pivot point, and the upper end of which carries a fulcrum roller element engaging the fulcrum-engaging upper surface of the rocker arm to define a variable fulcrum point. A control element in the form of a control piston driven by engine oil pressure positions the pivot arm and thus the fulcrum point to vary valve lift. To selectively restrict engine performance, a pressure relief valve may be provided for limiting the oil pressure to the control piston.申请人：DEWEY, III; ALBERT B.代理机构：Kerkam, Stowell, Kondracki & Clarke更多信息请下载全文后查看。
VARIABLE VALVE DRIVE
专利名称：VARIABLE VALVE DRIVE发明人：Hirschmann, Steffen,Malischewski, Thomas申请号：EP19167896.0申请日：20190408公开号：EP3564502A1公开日：20191106专利内容由知识产权出版社提供专利附图：摘要：The invention relates to a variable valve train (10), in particular with a sliding cam system (14), for an internal combustion engine. The variable valve train (10) includes a cam carrier (22) having first and second cams (28, 29) and first to third engagement tracks (32, 34, 36). A first actuator (24) is configured to engage the first engagement track (32) ina first axial direction in order to displace the cam carrier (22). A second actuator (26) is adapted to engage the second cam track (34) in a second axial direction opposite to the first axial direction to displace the cam carrier (22) and to displace the cam carrier (22) in the first axial direction to engage the third engagement track (36). The variable valve train (10) can have the advantage that even if the first actuator (24) fails, a displacement of the cam carrier (22) normally effected by the first actuator (24) is possible, namely by the second actuator (26).申请人：MAN Truck & Bus SE地址：Dachauer Strasse 667 80995 München DE国籍：DE代理机构：v. Bezold & Partner Patentanwälte - PartG mbB更多信息请下载全文后查看。
VARIABLE VALVE TRAIN CONTROL DEVICE
Variable valve device for engine
专利名称：Variable valve device for engine 发明人：Takahashi, Seigo,Ishigami, Hidetoshi 申请号：EP09000453.2申请日：20090114公开号：EP2080872A3公开日：20101027专利内容由知识产权出版社提供摘要：An object of the invention is to provide a variable valve device (35) capable of controlling a fuel injection amount or the like if a control shaft sensor (151) has a failure. The variable valve device employs a brushless DC motor (355) to rotate the control shaft (57), detects the rotation angle of the motor (355) using its magnetic pole sensors (152), and calculates an estimated rotation angle of the control shaft based on the rotation angle. The variable valve device further determines that the control shaft sensor has a failure if the difference between the actual rotation angle of the control shaft detected by the control shaft sensor and the calculated estimated rotation angle exceeds a prescribed value and controls the fuel injection amount, fuel injection timing and ignition timing of the engine (7) based on the calculated estimated rotation angle.申请人：Yamaha Hatsudoki Kabushiki Kaisha地址：2500 Shingai Iwata-shi Shizuoka-ken Shizuoka 438-8501 JP国籍：JP代理机构：Schoppe, Fritz更多信息请下载全文后查看。
怎样减少行驶阻力英语作文
怎样减少行驶阻力英语作文Title: Strategies to Reduce Driving Resistance。
Driving resistance, also known as rolling resistance, is a critical factor affecting the efficiency and fuel consumption of vehicles. It refers to the force that opposes the motion of a vehicle as it travels along a surface. Minimizing driving resistance is essential for enhancing fuel economy, reducing emissions, and improving overall vehicle performance. In this essay, we will explore various strategies to reduce driving resistance.1. Tire Selection and Maintenance:Proper tire selection and maintenance play a significant role in reducing driving resistance. Lowrolling resistance tires are designed to minimize friction between the tire and the road, thus improving fuel efficiency. Regular tire maintenance, including proper inflation, alignment, and rotation, ensures optimalperformance and reduces resistance.2. Aerodynamic Design:Aerodynamic drag accounts for a significant portion of driving resistance, especially at higher speeds. Streamlined vehicle designs, such as curved body shapes and smooth contours, help reduce aerodynamic drag. Featureslike air dams, side skirts, and rear spoilers further enhance aerodynamic efficiency, ultimately decreasing driving resistance.3. Vehicle Weight Reduction:Excessive vehicle weight increases rolling resistance and fuel consumption. Manufacturers can employ lightweight materials such as aluminum, carbon fiber, and high-strength steel in vehicle construction to reduce weight. Additionally, optimizing vehicle components and eliminating unnecessary accessories contribute to weight reduction, thereby lowering driving resistance.4. Engine Efficiency:Engine efficiency directly impacts driving resistance. Advanced technologies such as turbocharging, direct injection, and variable valve timing improve engine performance and reduce fuel consumption. Furthermore, hybrid and electric powertrains offer opportunities for regenerative braking and energy recovery, effectively reducing driving resistance during deceleration.5. Smooth Driving Habits:Driver behavior significantly influences driving resistance. Aggressive driving behaviors such as rapid acceleration, harsh braking, and excessive speed increase resistance and fuel consumption. Encouraging smooth driving habits, including gradual acceleration, maintaining steady speeds, and anticipating traffic flow, can significantly reduce driving resistance and enhance fuel efficiency.6. Road Surface Maintenance:Road surface conditions affect driving resistance. Smooth, well-maintained roads offer lower resistance compared to rough or uneven surfaces. Regular road maintenance, including resurfacing, filling potholes, and repairing cracks, ensures optimal driving conditions, thereby reducing resistance and improving fuel economy.7. Use of Advanced Lubricants:Lubricants play a crucial role in reducing friction within the vehicle's engine and drivetrain components. Utilizing high-quality, low-viscosity lubricants reduces internal friction, leading to lower driving resistance and improved efficiency. Regular lubricant changes and proper maintenance further enhance performance and longevity.In conclusion, reducing driving resistance is essential for enhancing vehicle efficiency, reducing fuel consumption, and minimizing environmental impact. By implementing strategies such as tire selection and maintenance, aerodynamic design, weight reduction, engine efficiency improvements, smooth driving habits, road surfacemaintenance, and the use of advanced lubricants, drivers and manufacturers can effectively minimize driving resistance and optimize overall vehicle performance. Through collective efforts and technological advancements, we can pave the way towards a more sustainable and energy-efficient transportation system.。
Automotive Systems and Control
Automotive Systems and Control Title: The Evolution of Automotive Systems and Control Introduction: The automotive industry has witnessed significant advancements in systems and control technologies over the years. From the early days of mechanical controls to the integration of sophisticated electronic systems, the evolution of automotive systems has revolutionized the driving experience. This essay explores the various perspectives surrounding the development and importance of automotive systems and control. Paragraph 1: One perspective on automotive systems and control focuses on the improvement of safety. Modern vehicles are equipped with advanced safety features such as anti-lock braking systems (ABS), electronic stability control (ESC), and adaptive cruise control (ACC). These systems enhance the driver'sability to maintain control of the vehicle, avoid collisions, and mitigate the severity of accidents. The integration of sensors, actuators, and control algorithms has greatly contributed to reducing the number of road accidents and saving lives. Paragraph 2: Another perspective emphasizes the role of automotive systems and control in enhancing fuel efficiency. With the increasing concern for environmental sustainability, automakers have been investing in technologies that improve fuel economy. Systems like engine management control, variable valve timing, and start-stop systems optimize the combustion process, reduce energy losses, and minimize fuel consumption. These advancements not only benefit the environment but also provide cost savings to vehicle owners. Paragraph 3: The integration of automotive systems and control has also led to the development of autonomous driving technology. This perspective highlights the potential for self-driving vehicles to transform the future of transportation. By combining various sensors, cameras, and artificial intelligence algorithms, autonomous vehicles can perceive their surroundings, make informed decisions, and navigate without human intervention. This technology has the potential to enhance mobility, reducetraffic congestion, and improve overall road safety. Paragraph 4: However, there are concerns regarding the reliance on automotive systems and control. Critics argue that the increasing complexity of these systems makes vehicles more vulnerable to cyber-attacks and malfunctions. The interconnectedness of various components and the reliance on software raise concerns about the potential forhacking and unauthorized access. Additionally, the dependence on advanced technology may lead to a loss of driving skills and a lack of human control, which some argue can diminish the overall driving experience. Paragraph 5: From an economic perspective, automotive systems and control have created new job opportunities and stimulated innovation. The development and implementation of these technologies require a skilled workforce, from engineers designing control systems to technicians maintaining and repairing them. Moreover, the integration of automotive systems has paved the way for new business models, such as ride-sharing and mobility-as-a-service, which have disrupted traditional transportation industries. Conclusion: The evolution of automotive systems and control has transformed the automotive industry, enhancing safety, fuel efficiency, and mobility. While there are concerns about cybersecurity and the loss of human control, the benefits outweigh the risks. As technology continues to advance, it is crucial to strike a balance between automation and human involvement to ensure a seamless and enjoyable driving experience. The future of automotive systems and control holds immense potential, and it will be fascinating to witness further advancements in this field.。
VVA_Sept_Tradeshow
2012 AND BEYOND
2012 AND BEYOND
Evolve is the next step in valve motion flexibility. The system enables HCCI by early intake closure, modifying the effective compression ratio. As you move beyond 2012, our VVA platform evolves with you to meet new emissions standards. VVA enables engineers to balance trade-offs between fuel economy and emissions. It all starts with the most powerful engine brake ever developed.
LOWER EMISSIONS OPTIMIZED FUEL CONSUMPTION EXHAUST GAS TEMPERATURE CONTROL INCREASED LOW-SPEED TORQUE IMPROVED TRANSIENT RESPONSE
2010 EARLY EXHAUST VALVE OPENING LATE INTAKE VALVE ENDING
Call 1.800.269.6562 ext. 7671 to learn more.
JACOBS® EVOLVE™ VVA GLOBAL DEVELOPMENT
TESTIMONIAL
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Michael Schittler – Industry Consultant; Former Vice President, Development Engines, Powertrain Business, Daimler Chrysler and Michael Brands – Industry Consultant; Former Executive Engineer, Heavy Duty Engineering, Cummins During Joint Technical Council, May 2006
汽油机泵气损失特性及其对性能的影响
汽油机泵气损失特性及其对性能的影响杨弢;杜爱民;万玉【摘要】According to the geometric parameters, test data and boundary conditions of an 1.8L naturally aspirated gasoline engine, one -dimensional simulation models were modeled .On the basis of simulation results of gasoline engine, pumping loss characteristic, thermal efficiency characteristic and BSFC characteristic of part load were analyzed.The results show that pressure drop at throat increases , pumping loss raises, indicated effi-ciency decreases and fuel economy deteriorates with the decrease of the load , which means that reducing pressure drop at throat is important to reduce pumping loss , increase thermal efficiency and reduce BSFC .% 根据某型号1.8L 自然吸气汽油机的几何参数、试验数据和边界条件，建立一维仿真模型，分析了汽油机部分负荷的泵气损失特性、热效率特性和油耗特性，结果显示部分负荷时随着负荷的降低，节气门处压力损失增加，泵气损失增加，指示热效率降低，燃油经济性恶化，表明降低节气门处的压力损失对降低汽油机的泵气损失，提高热效率，降低燃油经济性有重要意义.【期刊名称】《佳木斯大学学报（自然科学版）》【年(卷),期】2012(000)006【总页数】5页(P839-843)【关键词】汽油机;泵气损失;热效率【作者】杨弢;杜爱民;万玉【作者单位】同济大学汽车学院,上海 201804;同济大学汽车学院,上海 201804;同济大学汽车学院,上海 201804【正文语种】中文【中图分类】U4640 引言传统汽油机采用节气门控制负荷，在部分负荷工况时通过调节节气门对进气量进行控制，由于进气压力降低，使缸内压力远低于大气压，活塞运行过程中需要消耗较多的功来克服两端的压力差，形成泵气损失，造成热效率的降低.这是影响汽油机部分负荷经济性的主要原因之一.因此，研究汽油机部分负荷工况下泵气损失特性及其对性能的影响，分析如何降低泵气损失，对提高汽油机部分负荷热效率，降低燃油经济性有重要意义.本文通过对某型号1.8L汽油机工作过程的模拟，分析了其泵气损失特性及其对汽油机性能的影响.1 仿真计算模型建立1.1 仿真模型建立利用GT－POWER模拟仿真软件搭建某型号1.8L自然吸气汽油发动机计算模型.根据原机实际测量的数据，包括管道长度、直径、弯曲半径、熔剂元件体积(空气滤清器、谐振腔、三元催化器、消声器)等，建立如实际发动机较为相符的计算模型，模型的主要元件有:进气管道、空气滤清器、节气门、进气道、喷油器、进气门、排气门、气缸、曲轴箱、排气道、排气管以及传感器和监视器等.部分负荷时，利用传统的PID(Proportion Integration Differentiation)控制模块的来控制计算过程中进气流量，以实现对负荷的控制.根据试验确定仿真计算模型各工况边界条件，该汽油机为进气门单VVT，各工况条件下排气门正时保持不变.根据相关几何条件及物理边界条件，在GT－POWER平台上建立一维仿真计算模型，如图1所示:1.2 万有特性模拟及验证根据试验提供的边界条件，从1000r/min到6000r/min，每隔500r/min取一个工况点，共11个工况点，建立汽油机部分负荷模型，模拟仿真汽油机负荷特性，并对计算结果进行分析处理，得到汽油机油耗特性Map和流量特性Map，如图2、图3所示:与汽油机试验数据进行了对比和差值计算，得到仿真模型油耗特性和流量特性的误差Map如图4、图5所示:由图2、图3、图4、图5可以看出，仿真计算得到的油耗特性和流量特性趋势以及变化方位与原汽油机试验数据较为匹配，且油耗特性和流量特性与试验数据的误差基本在±5%之间，只有流量特性在个别工况点出现了大于5%情况，这些工况点为低速第负荷或者为高速高负荷，是仿真计算处理较为困难的区域，而且其误差在9%以内，不会对后期的计算产生太大的影响.由此可见，根据试验建立的一维仿真计算模型，可以较为准确模拟汽油机的工作过程，为后期的分析和改进提供基础. 图1 1.8L自然吸气汽油机GT－Power仿真模型图2 模拟值油耗特性Map图3 模拟值流量特性Map2 泵气损失特性及其对性能的影响2.1 泵气损失特性从1000r/min到6000r/min，每隔500r/min取一个工况点，共11个工况点，模拟仿真发动机负荷特性，计算过程中排气正时保持不变，排气提前角为47.2deg BBDC，排气迟闭角为 8.5deg ATDC.图6、图7分别为不同工况下泵气损失(PMEP)以及泵气损失在IMEP中所占的比例.图4 模拟值油耗特性误差Map图5 模拟值流量特性误差Map由模拟计算结果可以看出，随着转速的增加，泵气损失及其在IMEP中所占的比例增加;随着负荷的降低，泵气损失增加，而且泵气损失在IMEP中所占的比例也随着负荷的降低而增加，且这种趋势在低速时更加明显.以2000r/min为例，IMEP 从8bar降低到2bar，泵气损失从0.35bar增加到0.62bar，其在 IMEP中所占比例也由4.2%上升到31.4%.图6 泵气损失特性图7 IMEP中泵气损失比例图8 热效率与IMEP关系特性曲线2.2 泵气损失对指示热效率和燃油经济性的影响随着负荷的降低，泵气损失及其在IMEP中的比例增加;负荷降低，可燃混合气充量降低，缸内气体运动强度降低，燃烧效率降低，对指示热效率和燃油经济性产生影响.图8、图9、图10、图11是指示热效率和燃油经济性随着IMEP和泵气损失的变化趋势.图9 热效率与PMEP关系特性曲线图10 BSFC与IMEP关系特性曲线图11 BSFC与PMEP关系特性曲线由模拟结果可以发现，相同负荷，随着转速的增加，热效率降低，比油耗增加;相同转速下，随着负荷的降低，热效率降低，比油耗增加;相同转速下，随着泵气损失的增加，热效率降低，比油耗增加.以2000r/min为例，IMEP从8bar降低到2bar，热效率从36.75%降低到29.71%，比油耗从增加到.可见，随着负荷的降低，泵气损失增加，造成热效率降低，燃油经济性恶化.而且在低速的时候，随着负荷的降低，泵气损失的增加，热效率降低和比油耗增加的趋势要明显比高速时快.图12 2000r/min时不同负荷示功图图13 进气压力与IMEP变化关系图14 节气门处压力降与IMEP变化关系2.3 泵气损失产生的原因分析通过示功图分析汽油机工作过程中泵气损失产生的原因.以2000r/min为例，图12为2000r/min不同负荷时仿真得到的示功图.图15 节气门处压力降与PMEP变化关系图16 进气门压力与IMEP变化关系图17 进气门压力降与IMEP变化关系可见，随着负荷的降低，进气过程中缸内压力降低，而排气压力基本保持不变，换气过程中做功面积增加，泵气损失增加.模拟结果如图13、图14、图15、图16、图17所示:可以发现，随着转速的变化，进气压力变化不大，且在节气门处的压力降也变化不大，进气门压力变化不大，进气门压力损失随着速度的增加有略微增加，说明相同负荷下随着速度增加，进气泵气损失增加量较小，结合前面关于相同负荷下泵气损失随着速度的增加而增加的结论，可以得出:相同负荷下，随着速度的增加，进气泵气损失略微增加，排气泵气损失的增加是整体泵气损失增加的主要部分.随着负荷的降低，进气过程中节气门和进气门处的进气压力也随之降低，流经节气门和进气门处产生的压力损失越大，对应的泵气损失也越大.由图12可以看出，低速小负荷下，节气门处的泵气损失是整体泵气损失的主要部分.泵气损失大小与节气门处压力降和气门处压力降基本成正比，但是进气门随着发动机的结构设计完成后就无法改变了.这样，实际发动机运行中，泵气损失是随着节气门处压力损失的增大而增大，节气门开度越小，节流作用越强，节气门处压力损失越大，进气压力越低，泵气损失越大［1］.随着转速和负荷增加，排气压力增加，这造成在高速高负荷时泵气压力增加.进一步分析节气门控制模式对进气量的影响可知，传统汽油机配气机构的进气相位一定，进气门关闭时刻不变，进而进气门关闭时刻的缸内容积基本一致.这样，在均质混合气情况下，如果要调整负荷，就必须控制进气量.而在缸内容积一定的情况下，进气量的控制只能通过降低混合气的密度来实现，这就需要降低进气压力.在传统汽油机中主要通过控制节气门的开度来实现负荷的控制.然而，在这种负荷控制模式中，进气压力随负荷降低而降低，这必然导致泵气损失的增大［1］.由以上的计算分析可以看出，部分负荷时控制节气门处的压力损失是降低泵气损失关键所在，对提高热效率和燃油经济性有重要意义.3 结论1)建立的某型号1.8L自然吸气发动机一维仿真模型可以在不同负荷下很好的模拟发动机的工作过程，其误差在工程可允许范围内.2)相同负荷下，随着速度的增加，进气泵气损失略微增加，排气泵气损失的增加是整体泵气损失增加的主要部分.3)随着发动机负荷的降低，节气门的开度减小，由于节气门的节流作用，使得节气门处压力损失增加，导致泵气损失增加［1］，指示热效率降低，燃油经济性恶化.4)部分负荷时，降低发动机的泵气损失关键在于降低节气门处的压力损失，这对提高热效率，降低燃油消耗有重要意义.参考文献:［1］胡顺堂.全可变气门机构汽油机泵气损失控制及对燃烧过程的影响［D］.天津:天津大学，2009.［2］田永祥.混合动力汽车用艾金森循环汽油机工作过程及实现方法研究［D］.上海:同济大学，2009.［3］何世泉.4G10汽油机配气机构整体分析及改进设计［D］.上海:同济大学，2008.［4］Shiau CSN，Kaushal N，Hendrickson CT，etal.Optimal Plug－In Hybrid Electric Vehicle Design and Allocation for Minimum Life Cycle Cost，Petroleum Consumption，and Greenhouse Gas Emissions［J］.Journal of Mechanical Design，2010，132.［5］J.M.Mallikarjuna，V.Ganesan.Theoretical and Experimental Investigations of Extended Expansion Concept for SI Engines［J］.SAE，2001，2002－01－1740.［6］Jorge J.G.Martins，KrisztinaUzuneanu，Bernardo SousaRibeiro.Thermodynamic Analysis o f an Over－ Expanded Engine［J］.SAE.2004－01－0671.［7］Oswaldo Mendes Fran?a.Impactof the Miller Cycle in the Efficiency of an FVVT(Fully Variable Valve Train)Engine During Part Load Operation ［J］.SAE.2009，2009 －36 －0081.。
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Delphi Corp.
VARIABLE VALVE TRAIN TECHNOLOGY HELPS ENHANCE THE GASOLINE ENGINE
W
Valve train improvements are an important part of the continued efciency advancements of internal combustion engines. Today's electronics allow more precise control and different approaches to valve train design.
deliver signicantly higher-performance benets in smaller, lighter, more efcient packages that use conventional 87 octane unleaded gasoline. And they do so without the need for massive investments in the fueling infrastructure, exotic technologies or sacrices in engine performance. The reason, of course, has been an evolution in engine technology made possible by an array of innovations in electronics beginning in the early 1980s with electronic fuel injection and "variable displacement" cylinder deactivation. It wasn't until about 10 years ago that electronics really began moving the needle in engine technology with the high-volume application of sophisticated electronically controlled variable valve train technologies. These developments are enabling the gasoline-powered engine to cost effectively realize its full potential in fuel economy, emissions and performance. The most signicant advances have occurred in three areas: continuously variable cam phasing; cam phasing combined with two-step valve lift; and cylinder deactivation. While the future of automotive powertrains appears to be hybrids in the near and mid-term and fuel cells long-term, advanced electronic systems like these valve train control systems provide practical, cost-effective answers today.
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WARD'S AUTO ELECTRONICS | MAY 2005
Like racing—"How fast can you afford to go?"—there is a cost associated with fuel economy, emission and performance improvements, and these valve train enhancements provide cost-effective gains that are competitive with more glamorous, revolutionary approaches. For example, vehicle manufacturers can get a 2% improvement in these qualities with a modest investment of say about $50 in valve train enhancements vs. about a 15% gain with a hybrid that requires an investment of several thousand dollars. So the dollar per percent improvement in valve train technology is extremely affordable. Today's IC engines perform very well in the real world in terms of fuel economy and are relatively robust to environmental and operational variation. Hybrids, which deliver good fuel economy in controlled test environments, may not perform as well
hile the motoring public waits breathlessly for the promise of a revolution in powertrain technology to materialize, the venerable gasoline-powered internal combustion (IC) engine has quietly been evolving into an increasingly cleaner, more fuel-efcient power source. In fact, today's cars and trucks
new level with the high-volume application of continuously variable cam phasing.
CONTINUOUSLY VARIABLE CAM PHASING
Continuously variable cam phasing changes the timing of the valve train as the engine operating conditions change—idling in trafc, launching and accelerating, towing a trailer or cruising at highway speeds—improving fuel economy and reducing hydrocarbon and NOx emissions. This is accomplished by shifting the intake and/or exhaust cam as required on dual overhead cam engines to broaden the torque curve, increase peak power at high rpms and improve idle quality. In the Delphi continuously variable vane-type cam phaser system, the variable cam phaser (VCP) replaces the standard pulley or sprocket. This enables it to optimize their angular relationship while the engine is running based upon the operating parameters of the engine. Various strategies can be used in applying this technology: one on the intake cam, one on the exhaust or both—a dual independent cam phasing strategy. Fuel economy gains can range from 1% to 4%, depending on the fuel economy vs. performance trade-off strategy used. For example, if the value to the vehicle builder is $20 per percentage point per vehicle, some very large paybacks can be realized from investments in this technology alone. Today, Delphi estimates that at least 50% of the market has engines using cam phasing and likely this technology will be applied to virtually all production engines within the next six years or so. The value equation makes sense. The system cost is minimal and the engine builders can usually eliminate their EGR system while getting better fuel economy, more horse-