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US 5,558,068 AGranted
Solenoid valve unit for fuel injection apparatus
AssigneeZexel Corporation
InventorsAkira Kunishima, Tomiaki Hasebe, Hideya Kikuchi, Etsuro Hozumi, Takeo Kushida
Life of this patent
Estimating the term…
Abstract
A solenoid valve unit for a fuel injection apparatus suppresses fuel vaporization when the engine is being started or restarted when hot and enhances the reliability of engine operation by providing a stable fuel delivery during engine startup.
Claims24
A fuel injection apparatus comprising:
- a low-pressure pump that supplies fuel at low pressure from a fuel tank,
- an injector, a high-pressure pump that is connected with and that receives the low-pressure fuel from the low-pressure pump and that supplies the fuel at high pressure to the injector that injects the fuel at high pressure into an engine,
- a solenoid valve unit comprising:
- a unit housing provided with a high-pressure lead-in port from the injector, a low-pressure lead-out port to the fuel tank, a return port from the high-pressure pump, a high-pressure passage in communication with the lead-in port, a low-pressure passage in communication with the lead-out port, and a return port passage in communication with the return port,
- a pressure control valve that opens and closes the high-pressure and low-pressure passage in accordance with pressure at the lead-in port, and
- solenoid valves able to communicate with the lead-in port and lead-out port via the pressure control valve and able to open and close communication between the high-pressure passage and the low-pressure passage, and between the low-pressure passage and the return port passage,
- wherein the solenoid valves are controlled to open communication between the high-pressure passage and the low-pressure passage and close communication between the low-pressure passage and the return port passage during engine startup, and to close communication between the high-pressure passage and the low-pressure passage, and open communication between the low-pressure passage and the return port passage during normal engine operation.
4 more elements
A fuel injection apparatus comprising:
- a low-pressure pump that supplies fuel at low pressure from a fuel tank,
- an injector, a high-pressure pump that is connected with and that receives the low-pressure fuel from the low-pressure pump and that supplies the fuel at high pressure to the injector that injects the fuel at high pressure into an engine,
- a solenoid valve unit comprising:
- a unit housing provided with a high-pressure lead-in port from the injector, a low-pressure lead-out port to the fuel tank, a high-pressure passage in communication with the lead-in port, and a low pressure passage in communication with the lead-out port,
- a high-pressure control valve that opens and closes the high-pressure passage and low-pressure passage in accordance with pressure at the lead-in port,
- a solenoid valve that is able to communicate with the lead-in port and lead-out port via the high-pressure control valve and can open and close communication between the high-pressure passage and the low pressure passage,
- a check valve arranged between the low-pressure passage and the fuel tank, and
- a low-pressure control valve arranged between the high-pressure pump and the fuel tank,
- wherein an opening pressure of the low-pressure control valve is set at a higher pressure than the valve opening pressure of the check valve and the solenoid valve is controlled to open communication between the high-pressure passage and the low-pressure passage during engine startup, and to close communication between the high-pressure passage and the low-pressure passage during normal engine operation.
6 more elements
A fuel injection apparatus comprising:
- a low-pressure pump that supplies fuel at low pressure from a fuel tank,
- an injector, a high-pressure pump that is connected with and that receives the low-pressure fuel from the low-pressure pump and that supplies the fuel at high pressure to the injector that injects the fuel at high pressure into an engine,
- a solenoid valve unit comprising:
- a unit housing provided with a high-pressure lead-in port from the injector, a low-pressure lead-out port to the fuel tank, a high-pressure passage in communication with the lead-in port, and a low-pressure passage in communication with the lead-out port,
- a high-pressure control valve that opens and closes the high-pressure passage and low-pressure passage in accordance with pressure at the lead-in port,
- a solenoid valve that is able to communicate with the lead-in port and lead-out port via the pressure control valve and can open and close communication between the high-pressure passage and the low-pressure passage, and
- a low-pressure control valve arranged between the high-pressure pump and the fuel tank,
- wherein the orifice in the high-pressure passage is of a diameter that allows the valve opening pressure of the low-pressure control valve to be set at a higher pressure than the pressure in the high-pressure passage when the solenoid valve is set at open and the solenoid valve is controlled to open communication between the high-pressure passage and the low-pressure passage during engine startup, and to close communication between the high-pressure passage and the low-pressure passage during normal engine operation.
5 more elements
A fuel injection apparatus comprising:
- a low-pressure pump that supplies fuel at low pressure from a fuel tank,
- an injector, a high-pressure pump that is connected with and that receives the low-pressure fuel from the low-pressure pump and that supplies the fuel at high pressure to the injector that injects the fuel at high pressure into an engine,
- a solenoid valve unit comprising:
- a unit housing provided with a high-pressure lead-in port from the injector, a low-pressure lead-out port to the fuel tank, a high-pressure passage in communication with the lead-in port, and a low-pressure passage in communication with the lead-out port, said high-pressure passage having an orifice formed therein,
- a high-pressure control valve that opens and closes the high-pressure passage and low-pressure passage in accordance with pressure at the lead-in port, and
- a solenoid valve that can open and close communication between the high-pressure passage and the low-pressure passage,
- wherein the solenoid valve and the high-pressure control valve are integrated by making common use of a valve element thereof.
4 more elements
Dependencies are inferred from the claim text.