Chapter 4 Gasoline management_09.pptVIP

Chapter 4 Gasoline management (汽油机管理) Contents 1 Technical requirements（技术要求） 2 Cylinder charge（气缸充量） 3 Mixture formation（混合气形成） 4 Air supply（空气供给） 5 Fuel supply（燃料供给） 6 Ignition（点火） 1）Spark-ignition engine torque (点燃式发动机转矩) The Power P furnished by the spark-ignition engine is determined by the available net flywheel torque and the engine speed.(点燃式发动机产生的功率是由飞轮输出的净转矩和发动机转速决定的） In Bosch engine-management systems featuring electronic throttle control (ETC), the “cylinder-charge control” subsystem determines the required induction-air mass and adjusts the throttle-valve opening accordingly. The driver exercises direct control over throttle-valve opening on conventional (传统)injection systems via the physical link with the accelerator pedal. The “mixture formation” subsystem calculated the instantaneous mass fuel requirement as the basis for determining the correct injection duration （ 喷油持续时间） The optimal injection time（最佳喷油时刻） The “ignition” subsystem determines the crankshaft angle that corresponds to precisely the ideal instant for the spark to ignite the mixture. The purpose of this closed-loop control system To provide the torque demanded by the driver while at the same time satisfying strict criteria in the areas of Exhaust emissions Fuel Consumptions Power Comfort and convenience(方便性) Safety The intake and exhaust valves open and close at specific points to control the transfer of fresh and residual gases.(进排气阀在某时刻开启和关闭以控制新鲜充量和残余废气的交换) The ramps on the camshaft lobes determine both the points and rates at which the valve open and close to define the gas-exchange process, and with it the amount of fresh gas available for combustion（凸轮轴轮廓型线决定了阀门开关时刻及速率以控制气体交换过程，从而决定了燃烧过程新鲜气体的量） Gas exchange A supercharging (or boost) effect can be obtained by exploiting dynamics within the intake manifold .The actual degree of boost will depend upon the manifold’s configuration as well as the engine instantaneous operating point. The optio