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US 2006/0065241 A1Published application
Fuel injection system for internal combustion engine
AssigneeDenso Corporation
InventorYoshihisa Yamamoto
Life of this patent
Estimating the term…
Abstract
A control valve is constructed as a two-position three-way valve. A switching port of the control valve and a control chamber of a pressure intensifier are connected to the control valve through a reciprocation passage. Fuel pressure in the control chamber is controlled by the control valve. The reciprocation passage is formed of two fuel passages for connecting the switching port of the control valve with the control chamber in parallel. One fuel passage is provided with a check valve for preventing fuel from flowing from the control chamber to the control valve and the other fuel passage is provided with a hydraulic valve for preventing the fuel from flowing from the control valve to the control chamber and a restrictor.
Claims16
A fuel injection system for an internal combustion engine comprising:
- an accumulator accumulating fuel in a state of a predetermined pressure;
- a pressure intensifier having a control chamber of which hydraulic pressure is increased or decreased when the fuel flows into or flows out and a hydraulic piston moving according to an increase or a decrease in the hydraulic pressure in the control chamber, the pressure intensifier intensifying a pressure of the fuel to be supplied from the accumulator by a pressure intensifying action of the hydraulic piston;
- an injection nozzle having a backpressure chamber of which hydraulic pressure is increased or decreased when the fuel flows into or flows out and a needle moving according to an increase or a decrease in the hydraulic pressure in the backpressure chamber, the injection nozzles injecting the fuel supplied by the accumulator or the fuel having pressure intensified by the pressure intensifier with a valve opening action by the needle;
- a hydraulic pressure supply passage supplying fuel pressure in the accumulator to the control chamber and the backpressure chamber;
- a hydraulic pressure release passage releasing fuel pressure in the control chamber and the backpressure chamber to a low pressure side;
- and
- a control valve provided in common in the hydraulic pressure supply passage and the hydraulic pressure release passage, and having a valve body driven by a two-position actuator and selectively opens and closes the hydraulic pressure supply passage and the hydraulic pressure release passage by the valve body to control an action of the pressure intensifier and an action of the injection nozzle,
- wherein the fuel injection system has two fuel passages that connect the control valve with the control chamber in parallel, one fuel passage being provided with a first flow direction control means for preventing the fuel from flowing from the control chamber to the control valve to form a portion of the hydraulic pressure supply passage, the other fuel passage being provided with a second flow direction control means for preventing the fuel from flowing from the control valve to the control chamber to form a portion of the hydraulic pressure release passage.
5 more elements
A fuel injection system for an internal combustion engine, the fuel injection system comprising:
- an accumulator accumulating fuel in a state of a predetermined pressure;
- a pressure intensifier having a control chamber of which hydraulic pressure is increased or decreased when the fuel flows into or flows out and a hydraulic piston moving according to an increase or a decrease in the hydraulic pressure in the control chamber, the pressure intensifier intensifying pressure of the fuel to be supplied from the accumulator by a pressure intensifying action of the hydraulic piston;
- an injection nozzle having a backpressure chamber of which hydraulic pressure is increased or decreased when the fuel flows into or flows out and a needle moving according to an increase or a decrease in the hydraulic pressure in the backpressure chamber, the injection nozzle injecting the fuel supplied by the accumulator or the fuel having pressure intensified by the pressure intensifier with a valve opening action by the needle;
- a hydraulic pressure supply passage supplying fuel pressure in the accumulator to the control chamber and the backpressure chamber;
- a hydraulic pressure release passage releasing fuel pressure in the control chamber and the backpressure chamber to a low pressure side;
- a first control valve provided in the hydraulic pressure supply passage and having a valve body driven by a two-position actuator, the first control valve opening or closing the hydraulic pressure supply passage by the valve body;
- and
- a second control valve provided in the hydraulic pressure release passage and having a valve body driven by a two-position actuator, the second control valve opening or closing the hydraulic pressure release passage by the valve body,
- wherein the first control valve and the second control valve control an action of the pressure intensifier and an action of the injection nozzle.
6 more elements
Dependencies are inferred from the claim text.