| 摘要 |
A distributor-type fuel injection pump for an internal combustion engine wherein the plunger has first and second portions with different diameters from each other, defining first and second pump working chambers, respectively. A communication passageway is arranged for communicating the second pump working chamber with fuel delivery passageways leading to respective fuel injection valves of the engine. A drain passageway is arranged for communicating the communication passageway with a zone under a lower pressure of the pump, and is selectively closed and opened by a selector valve. An electronic control unit is responsive to operating conditions of the engine for driving the selector valve to selectively assume closed and open positions. Fuel is pressure delivered to the fuel injection valves from one or both of the first and second pump working chambers, depending upon whether the selector valve assumes the closed position or the open position. The pump is so constructed that the plunger has an increased delivery stroke, when the selector valve is controlled by the control means to assume a predetermined one of the closed position and the open position and at the same time the control sleeve assumes a predetermined position relative to the plunger.
|
