| 摘要 |
1. Electronic-hydraulic timing control system for injection pumps (2) of fuel injection internal-combustion engines, particularly for fuel injection in diesel engines, comprising a processor (54) having a memory for the programme to be performed and data inputs (55) to which are connected sensors for the rpm command or accelerator pedal position, resp., and for operating data of the engine such as temperatures and pressures as well as engine speed and optionally engine torque, and outputs, to which are connected solenoid valves for a hydraulic actuator (4, 17) in the form of a single-acting cylinder to be fed from a pressure source comprising a pump driven by the internal-combustion engine, said actuator engaging the transmission mechanism (3, 9-12) for driving the injection pump(s) (2) against spring action (13), the working chamber of said actuator being connectable to the pressure source or to a return pipe (32, 34) via a solenoid valve arrangement (23, 24, 56, 57), and a pressure reservoir (47) being connected to the pressure source via a check valve (46) opening to the pressure reservoir (47), characterised in that the working chamber of the actuator (4, 17) is connectable via at least one solenoid valve (23, 56, 57) either through a throttle (48) to the pressure source or to the pressure reservoir, and via a further solenoid valve (24) to the return pipe (32, 34), whereat all of the solenoid valves (23, 24, 56, 57) are controllable separately and in the electrical power-off condition the solenoid valve (23, 57) providing the connection to the throttle (48) is open and the solenoid valve (24) providing the connection to the return pipe (32, 34) is closed. |
