Fuel pump controlling apparatus for internal combustion engine

Abstract

Abstract PURPOSE:To prevent excessive supply of fuel through provision of a trouble detecting circuit consisting of a means for producing an operation signal by detecting operation of a fuel injection valve, a means for producing a trouble signal by judging whether the operation is normal or not and a means for stopping operation of a fuel pump in response to said trouble signal. CONSTITUTION:In case that a solenoid 3a of an injection valve 3 is earthed at the side of a transistor Tr1 or its collector and emitter are short-circuited by some reason or other, the collector voltage Vb is reduced to zero independently of the input to the transistor Tr1. Resultantly, a transistor Tr2 is turned ON and a signal Vc takes a level of ''1'' and held at the level thereafter. In this state, if the level of an instruction signal Sa is changed from ''0'' to ''1'', the output of an exclusive OR circuit 21 is reduced to zero and the output of an NAND- circuit 22 takes a value ''1''. Immediately after then, if a rising pulse of an output signal Ve of an NAND-circuit 28 produced by the change of the signal S is impressed on an input terminal C of a flip-flop 23, the output ''1'' of the NAND- circuit 22 is put into an input terminal D and the flip-flop 23 is set.

Inventors

• 👤 Shunpei Hasegawa
• 👤 俊平 長谷川
• 👤 Kunro Umesaki
• 👤 梅咲　薫郎

Bibliographic Details