改进动力系统带来利润--文献翻译

Powering profits
How PSA is extracting more performance and profit from a new 2.2-litre engine
The ongoing success of the co-operation between PSA Peugeot Citroen and Ford (See Feature, page 38) is further illustrated by the introduction of an all-new 2.2-litre diesel engine for passenger cars. The inline four-cylinder engine was not included in the original framework agreement, signed in 1998. Its development suggests that the two groups are doing well out of the partnership.
The new 2.2-litre diesel engine resulting from the technical alliance between PSA and Ford was designed to meet an ambitious target. It had to offer the driveability of the best 2.5-litre engines on the market as well as better fuel efficiency and emissions levels.
The engine will be used on a number of platforms for upper mid-rang and executive cars produced by both manufacturers. The engineers also faced the challenge of improving pedestrian protection to meet incoming European legislation and to improve the engine’s noise characteristics.
Because downsizing had proved effective in earlier phases of their co-operation, PSA and Ford opted to keep the new engine small. They set the displacement at 2.2-litres to reduce fuel consumption and carbon dioxide emissions, without sacrificing any of its performance features.
The engine takes some interesting approaches in its design . Its “extreme conventional combustion system” (ECCS) features a combustion chamber design that reduces emissions by 30 percent while improving performance and noise.
The combustion chamber has a large diameter and low compression ratio, which produces a more uniform air/fuel mix. The size of the combustion chamber limits the amount of fuel in contact with the walls. This makes combustion more efficient.
The pistons’geometry had to be altered to create a 25 percent larger diameter combustion chamber compared with the previous engine generation. To withstand the extra stress and heat, the pistons had to be aluminium. The metal has very high mechanical and thermal properties.
The special geometry also significantly reduced swirl in the combustion chamber, thereby reducing heat loss to the walls and improving the engine’s efficiency. As a result, fuel efficiency under all driving conditions improved by 2 percent compared to the previous generation.
Remarkably, the new ECCS system did not require any changes in the production tooling for PSA’s DW family of engines. Parts are common to the other engines produced in this plant.
The engine’s common rail is a third-generation Bosch system that operates at a pressure of 1800 bar. The system uses piezoelectric injectors with seven nozzles. These can make up to six injections per cycle, make fuel dosing 135m
more precise. This in turn enhances management of the introduction rate, the ratio of the amount of diesel injected to the injection spray is finer, which reduces emissions, since the air/diesel mix is more uniform.
All the cars powered by the new engine will be equipped with maintenances-based filter technology, while Ford will use a catalyst-based filter.
To enhance drive ability, particularly the torque delivered at low revs, turbos were essential. PSA engineers developed two turbo charging systems for different versions of the engine in partnership with turbo firm Honeywell.
The more powerful 125KW version uses a parallel sequential dual turbo. This reaches a peak torque of 400Nm at just 1750rpm. Using a small, low-inertia turbo makes the same size kicks in at 2700rpm. Both turbos are controlled by the engine management system.
A second version, which can produce between 115 and 125 KW, uses a single variable geometry turbo. This reaches 400Nm at 2000rpm and will be used for applications that do not require the bi-turbo boost at low engine speed. Electrical control enables precise, fast management of the turbo’s variable geometry to optimize boost pressure across the entire operating range.
Despite the extra kit on the engine, the overall engine height is 40mm less than its predecessor. Its compact size will allow it to be used in a greater number of vehicles by the manufacturers. It also makes the engine less likely to injure a pedestrian in the event of an accident. Performance, rather than pedestrian safety was the main priority, however. The reduction an size is the result of extensive re-engineering work on the engine’s top end.
The cylinder head has a single cooling flow, which also reduces heat loss, and is made from an aluminum-copper alloy. The properties of the material give better thermo-mechanical performance. The uniform water system cools the cylinder head precisely, reducing the amount of water used and simplifying the process.
A double-wall crankcase was developed for the project to reduce the noise radiated from the engine by three decibels; significant in terms of customer perception, says PSA. A fast response throttle intake system is actuated when engine is shut-off to avoid any vibration when the driver stops the car. And two counter-rotating balance shafts keep vibration on the inline unit to a minimum.
The engine will be manufactured at PSA’s tremery plant in France, the world’s largest diesel factory. In 2005, its 4637 engineers and production workers produced 1.2 million units.
The facility uses batch production to avoid assembly errors caused by changing from one model to another. The batches are very large with several hundred identical engines following each other on the line.
The 2.2-litre unit will be subject to the same “red card” sysem as others at the plant. Engines are checked after each assembly station. If a defect is spotted, the complete engine is scrapped. No reworking can be performed on the line, so that high quality is built into every engine from the outset. It sounds costly, but PSA’s research has shown that the reduction in warranty costs greatly outweighs any additional production costs.
The overall investment for designing and producing the new engine is EUR 212m (RMB 2.1bn). research and development costs came to EUR 127m (RMB 1.3bn). By using existing tooling with only specific technical improvements,
production investment was limited to just EUR 85m (RMB 850m).
More than 300 people will be assigned to production of the engine. Built on the same line as PSA’s 2.0-litre engine, the use of existing tooling and processes meant that it took just 3300 hours of training for the operators to adapt their skills to the changes in their workstations.
PSA has reserved a capacity of 200000 2.2-litre units a year on the line. Considering that the current 2.2-litre engine is only produced at levels of 70000 a year, the French carmaker’s confidence in its latest creation must be high.
改进动力系统带来利润
标志雪铁龙集团如何从一种新型 2.2升发动机获取更多性能及利润
轿车全新式2.2升柴油机的问世进一步阐明了标志雪铁龙集团与福特公司之间合作的成功（参阅特别报道，第38页）。

直列四缸动机不包括在1998年签署的原始框架协议之内，它的开发表明双方合作关系良好。

源于标志雪铁龙集团与福特公司技术合作的新型2.2升柴油机为实现宏伟目标而设计。

它必须具有市面上2.5升最佳发动机的驱动性能，同时还具有较好的燃料效率及排放标准。

该发动机将用于双方制造商的中高级汽车等多种平台。

工程师也面临着提高行人保护措施，从而符合即将来临的欧洲立法及改善发动机噪声性能的难题。

由于其早期合作证明规模缩小十分有效，标志雪铁龙集团与公司决定仍将新型发动机设计为小型发动机。

他们在不损失其任何性能特点的基础上，将2.2升排量的发动机设计为可减少燃料消耗及二氧化碳排放物的形式。

该发动机在其设计过程中采用了一些有趣的方案。

它的“极其传统的燃烧系统（ECCS）”具有一个燃烧室结构，该结构能够在改善其性能及噪声的基础上减少30%的排放物。

该燃烧室较大的直径及较低压缩比，这能够生成更加均匀的空气与燃料混合物。

燃烧室的尺寸能够限制与内壁接触的燃料数量。

这能够使燃料更加有效。

与先前发动机类别相比，活塞的几何结构不得不改动以形成一个直径比原来大25%的燃烧室。

为承受额外应力及热量，活塞必须采用铝制结构。

因为它具有非常高的机械及热性能。

这一特殊的几何结构也大大降低燃烧室中的涡流，从而减少了内壁热损失并改善了发动机效率。

因此，与上一代发动机相比，所有驱动下的燃料效率提高了2%。

最显著的特点是新型ECCS系统无须改变标志雪铁龙集团DW系列发动机
的生产工装。

其零件与在该工厂生产的其他发动机相同。

该发动机的共轨采用了第三代博世系统，这一系统可在1800巴压力下运行。

该系统采用了压电喷油嘴及七个135微米的喷嘴。

这些装置每个循环可形成六次喷射，能够保证燃料喷射量更加精确。

这也同时提高了对引入率的控制或柴油喷射量与喷射时间的比率。

喷射射流较细有利于减少排放物，因为空气与柴油混合物更均匀。

所有由这种新型发动机驱动的汽车都将配备无须维护的柴油颗粒过滤器。

标志雪铁龙集团将采用一种基于添加剂的过滤器技术，而福特公司将采用一种基于催化剂的过滤器。

为了提高驱动性能，特别是提高低转速时的扭矩，涡轮是必须的装置。

标志雪铁龙集团的工程师与霍尼韦尔涡轮公司合作，针对不同版本的发动机开发了两种涡轮增压系统。

功率较强的125KW版本的发动机采用了一个平行连续复式涡轮。

这使发动机仅在1750转时就可达到400Nm的峰值扭距。

采用一种小型，低惯性的涡轮使发动机即使在较低转速时也可响应。

因为它太小以至于无法覆盖发动机整个工作范围，第二个同样大小的涡轮可以在2700转/分钟时冲入。

两个涡轮都由发动机操纵系统控制。

第二个版本发动机能够生成115至125KW的功率，该发动机采用了一种单式可变几何涡轮。

该涡轮可使发动机在2000转/分钟时达到400Nm扭矩，而且它将被应用于在较低发动机转速时无须双涡轮增压的领域。

电动控制系统能够精确，快捷的控制涡轮的可变几何结构一边在整个工作范围内增压。

尽管该发动机上设有额外装置，但是整个发动机高度比它上一代少40毫米。

由于其具有尺寸紧凑的特点
因此它将被各个制造商应用于大量车辆中。

同时，如果发生事故时它也能够保证发动机不大可能伤及行人。

然而，与行人安全相比，性能是首当其冲需要考虑的事项。

尺寸缩小是对发动机顶端大量再设计的结果。

汽缸盖具有一个同样可减少热损失的单式冷却流道，该汽缸盖由铝铜合金制成。

该合金材料的特性具有较好的热量机械性能。

均一的供水系统能够精确的冷却汽缸盖，从而减少所使用的水量并简化工序。

标志雪铁龙集团表示，针对该项目开发的双壁曲轴箱旨在将发动机辐射出的噪音减少三分贝，这对客户的感受非常重要。

快速响应的油门进气系统
能够在发动机关闭时启动以免司机停车时出现任何振动。

而且两个反转平衡轴能够将直列发动机的振动最小化。

这一发动机将在标志雪铁龙集团位于法国的特母利工厂生产，该工厂是世界上最大的柴油机工厂。

2005年，该工厂4637名工程师及生产工人生产了120万台发动机。

该工厂采用批量生产，以避免由一个模式向另一个模式转变造成的装配错误。

这些批次都很大，每个生产线有数百台相同的发动机彼此接续。

这种2.2升发动机将与该工厂生产的其他发动机一样受“红牌”系统的控制。

在每个装配站装配之后，发动机都需检验。

如果发现有任何缺陷，整个发动机将作废。

生产线上不能进行任何返工工作，以便保证从开始每台发动机就具有较高质量。

尽管这听起来成本很高，但是标志雪铁龙集团的研究表明保修成本减少带来的收益远大于任何附加生产成本。

设计及生产这种新型发动机的总投资为2.12亿欧元（人民币21亿元）。

研发成本共计1.27亿欧元（人民币13亿元）。

采用现有的工装及仅有专门的改造后技术，生产投资仅需8.5亿欧元（人民币85亿元）。

将有300多人将被分配生产这种新型先进的四缸发动机。

在标志雪铁龙集团生产2.0升发动机的生产线上生产，采用现有工装及工艺，这意味着只需花费3300个小时培训操作者将其技术适应其工作站的变化。

标志雪铁龙集团已储备了每年生产线生产20万台2.2升发动机的能力。

鉴于目前2.2升发动机每年仅生产七万台，这一法国汽车制造商必须对其最新创作具有很高的信心。