VALVE-TYPE FUEL INJECTION NOZZLE Russian patent published in 2004 - IPC

FIELD: mechanical engineering; fuel equipment of internal combustion engines. SUBSTANCE: invention is aimed at prevention of undesirable too long delivery of fuel for injection at malfunctioning of nozzle in operation which precludes breakage of engine caused by overfuelling. Internal combustion engine with valve-type nozzle is furnished with high-pressure fuel accumulator into which fuel is fed by high-pressure pump and which is connected by pressure line with pressure space of valve-type nozzle provided with needle. In direction of opening, needle is loaded by pressure prevailing in pressure space acting onto conical surface against closing force, and in direction of closing it is loaded at least mediately by pressure prevailing in distributing space and acting onto movable wall connected with needle of valve-type nozzle and limiting said distributing space. Force created by first pressure prevailing in distributing space builds up closing force which exceeds force acting onto conical surface in direction of opening of valve-type nozzle needle, also provided with distributing valve operated by electric drive. Valve opens drain channel connecting distributing space with relief space to decrease pressure prevailing in distributing space to value of second pressure at which closing force is built whose value is less than force acting in direction of opening. Safety valve is installed in pressure line by means of which high- pressure fuel accumulator is connected with pressure space at the moments which fuel injection should take place and is closed during separate phases of injection. Distributing space is connected with high-pressure fuel accumulator through first restrictor. Distributing valve with electric drive is made in form of 2/2 distributor. Said distributing space can be connected with relief space second restrictor whose passage section exceeds passage section of first restrictor. EFFECT: improved reliability of fuel injection. 21 cl, 10 dwg