Mitsubishi Jidosha Kogyo Kabushiki Kaisha

Seijiro Kotooka

Susumu Kohketsu

Keiki Tanabe

A controller ( ) of an accumulator fuel-injection apparatus opens a selector valve ( ) for injection rate switching for a short time between auxiliary injection and main injection, the selector valve controlling high-pressure fuel supply from a high-pressure accumulator ( ) to a fuel passage ( ) on the downstream side of a check valve ( ), whereby a fuel pressure higher than an auxiliary injection pressure and lower than a main injection pressure is formed in the fuel passage on the downstream side of the selector valve ( ). By opening, in this state, an on-off valve ( ) for injection timing control to start the main injection, a proper pressure higher than the auxiliary injection pressure and lower than the subsequent main injection pressure is established in the initial stage of main injection, improving fuel economy and exhaust-gas characteristic.

Accumulator fuel-injection apparatus

An accumulator fuel injection system for controlling an injection rate according to the operating state of an engine comprises: a first accumulation chamber for containing high-pressure fuel supplied by a fuel supply pump a first electromagnetic valve device provided in a fuel passage which connects the first accumulation chamber with a fuel injection valve the first electromagnetic valve switching the fuel passage between a connected state or a disconnected state; a branch passage branched from the fuel passage at downstream side of the first electromagnetic device the branch passage having sufficiently lower constant fuel pressure than fuel pressure in the first accumulation chamber and a second electromagnetic valve device provided in a fuel return passage connecting the fuel injection valve with a fuel tank the second electromagnetic valve device switching fuel, which is injected from the fuel injection valve between an injected state and an uninjected state; and control means for opening the first electromagnetic valve device prior to the opening of the second electromagnetic valve device and then opening the second electromagnetic valve device

Accumulator fuel injection system

A fuel injector to be used with a low-pressure fuel source and a high-pressure fuel source to provide a two-stage fuel injection has superior responsiveness of fuel pressure control and ease of mounting to an engine. The fuel injector has a housing mounted to a cylinder head of an engine; a fuel injection valve fitted in a first end of the housing and having a first control valve for controlling injection of fuel to a combustion chamber of the engine; a first conduit formed in the housing and having one end connecting with the fuel injection valve and its other end opening in a second end of the housing and connected to a high-pressure fuel source storing high-pressure fuel; a second control valve, fitted to the housing, for controlling a supply of high-pressure fuel to the fuel injection valve by opening and closing the first conduit; a second conduit formed in the housing and having one end connecting with the first conduit downstream of the second control valve and its other end opening in the housing and connected to a low-pressure fuel source storing low-pressure fuel at a low-pressure than the fuel pressure of the high-pressure fuel source; and a check valve fitted in the housing and being disposed to the second conduit, for allowing the inflow of low-pressure fuel from the low-pressure fuel source to the first conduit side. As a result, the dead volume between the second control valve, the check valve and the fuel injection valve is minimized and the responsiveness of fuel pressure control can be improved.

Growing community of inventors

Yokohama, Japan

Seijiro Kotooka