Nippondenso Co., Ltd.

Hidetoshi Dohshita

Yoshiya Ishii

Nobuyuki Fujitani

Yoshihisa Yamamoto

Hiroshi Okazaki

A stopping device for an engine supplied with fuel by a fuel injection pump including a change-over valve, and an actuator for actuating the change-over valve in response to an engine shutdown operation. The change-over valve is movable between a first position to which it moves at engine startup to connect a fuel tank with an inlet of a fuel supply pump driven by the engine and connect an outlet of the fuel supply pump with an inlet of the fuel injection pump, and a second position to which it moves in response to an engine shutdown operation to connect the inlet of the fuel injection pump with the inlet of the fuel supply pump and connect the outlet of the fuel supply pump with the fuel tank. The actuator includes a solenoid and a key switch operative to energize the solenoid to move the change-over valve to the first position in response to an engine startup operation, hold the change-over valve in the first position during engine operation, and de-energize the solenoid to move the change-over valve to the second position in response to an engine shutdown operation.

Stopping device for engine supplied with fuel by fuel injection pump

An electromagnetic selector valve for changing the fuel paths between the fuel tank, fuel supply pump and fuel injection pump of an engine is energized by an energization control unit including a monostable multivibrator only for a predetermined time interval just after the engine key switch has been turned off. An on-off valve disposed in the pipe line between the fuel tank and the electromagnetic selector valve or the pipe line between the electromagnetic selector valve and the fuel injection pump, is opened during the time the engine is operating. When necessary, the on-off valve is continuously opened by another energization control unit including a monostable multivibrator for a predetermined time interval just after the engine key switch has been turned off.

Engine stop apparatus

A fuel injection system for an internal combustion engine of the type so-called unit injector wherein the overflow of fuel under high pressure from a plunger chamber defines the fuel injection cut-off. In order to perform the sharp cut-off, an overflow passage is increased in cross sectional area, and in order to prevent the overflow from the plunger chamber while the fuel is being charged into it, a flow control means such as a spool type directional control valve is inserted into the overflow passage so that when the fuel is being charged into the plunger chamber the communication between the overflow passage and a fuel tank may be positively interrupted. In addition, in order to prevent the fuel recharge with the resulting secondary injection, a flow control means such as a solenoid operated directional control valve is inserted into a fuel supply line communicating between a fuel delivery source and the plunger chamber such that as long as the fuel injection continues or when the fuel injection is zto be completed, the communication between the plunger chamber and the fuel delivery source may be completely cut off.

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Okazaki, Japan

Hidetoshi Dohshita