Pressure storage fuel injection system
AssigneeMitsubishi Jidosha Kogyo Kabushiki Kaisha
InventorAkio Ishida
Life of this patent
Estimating the term…
Abstract
A pressure storage (common rail) fuel injection system for an engine is provided, in which the fuel injection pressure rise response when quickly accelerating the engine is improved, engine output shortage is prevented, engine noise is reduced, and improvement is made with respect to soot generation and exhaust gas particulation. A booster is provided to boost pressurized fuel fed out from a pressure storage with a directional control valve for piston operation. Low pressure fuel injection in which fuel from the pressure storage is fed directly to fuel injection valve for injection, and high pressure fuel injection in which fuel having been boosted by the booster is fed to the fuel injection valve for injection, are switched one over to the other by a directional control valve for fuel injection control.
Claims19
A pressure storage fuel injection system comprising:
- fuel feeding means for feeding fuel of a predetermined pressure;
- a pressure storage for storing fuel fed out from the fuel feeding means in a pressurized state;
- a fuel feeding line for feeding fuel from the pressure storage to a fuel pool provided in a fuel injection valve for fuel to be injected;
- a fuel control line branching from the fuel feeding line and leading to a fuel chamber formed for needle valve on-off control in the fuel injection valve;
- a first directional control valve provided for fuel injection control in the fuel control line, the first directional control valve being operable to apply a fuel pressure to the fuel chamber so as to close the needle valve in the fuel injection valve and cease application of the fuel pressure to the fuel chamber so as to open the needle valve;
- a first cylinder chamber formed in the fuel feeding line;
- a boosting piston provided in the first cylinder chamber and operable for reducing a volume of the first cylinder chamber so as to boost the fuel pressure on the downstream side of the first cylinder chamber;
- a fuel supply circuit for supplying fuel from said pressure storage to said fuel feeding line and to the boosting piston;
- a second directional control valve provided for operating the boosting piston in the fuel supply circuit and operable to on-off switch application of fuel pressure to the boosting piston, thus driving the boosting piston;
- and
- a controller for providing control signals to the first directional control valve for the fuel injection control and the second directional control valve for operating the boosting piston to control the on-off control of the needle valve and operation of the boosting piston.
A pressure storage fuel injection system comprising:
- fuel feeding means for feeding fuel of a predetermined pressure;
- a pressure storage for storing fuel fed out from the fuel feeding means in a pressurized state;
- a fuel feeding line for feeding fuel from the pressure storage to a fuel pool provided in a fuel injection valve for fuel to be injected;
- operating fluid feeding means for feeding pressurized operating fluid;
- a valve control line for supplying the operating fluid from the operating fluid feeding means to an operating fluid chamber formed for on-off control of a needle valve in the fuel injection valve;
- a first directional control valve provided for fuel injection control in the valve control line, the first directional control valve being operable to apply an operating fluid pressure to the operating fluid chamber so as to close the needle valve in the fuel injection valve and cease application of the operating fluid pressure to the operating fluid chamber so as to open the needle valve;
- a first cylinder chamber formed in the fuel feeding line;
- a boosting piston provided in the first cylinder chamber and operable for reducing a volume of the first cylinder chamber so as to boost fuel pressure on a downstream side of the first cylinder chamber;
- a boosting piston control line for supplying the operating fluid from the operating fluid feeding means to the boosting piston;
- a second directional control valve provided for operating the boosting piston in the boosting piston control line and operable to on-off switch application of operating fluid to the boosting piston, thus driving the boosting piston;
- and
- a controller for providing control signals to the first directional control valve for the fuel injection control and the second directional control valve for operating the boosting piston to control the on-off control of the needle valve and operation of the boosting piston.
Dependencies are inferred from the claim text.