| 摘要 |
An i.c. engine has a variable volume combustion chamber 13, an air intake system 18, 20, 21, an exhaust system 17 and a fuel injection system comprising an injector 19 which functions as a positive displacement pump. The fuel injector 19 comprises a fuel chamber 52 with inlet and outlet passages 50, 54 controlled by respective one-way valves 51, 53. A spring-biassed piston 55 having an end plate armature 58 is slideable in the chamber 52 and is surrounded by a solenoid 57 connected to ECU 23. Reciprocal movement of the piston 55 acts to draw fuel into, and force fuel from, the chamber 52. Since the piston moves between fixed end stops, the injector dispenses a fixed amount of fuel for each and every operation of the injector. Thus the total amount of fuel delivered per engine cycle is controlled by the ECU 23 by controlling the number of operation of the injector per cycle in response to engine load as sensed by the position of the throttle valve 21. The or each engine cylinder may be provided with two injectors dispensing unequal amounts of fuel. The simple fuel injection system is suitable for small, low-power engines, eg for lawn mowers or other garden equipment. |
