Pressure accumulator device for a motor vehicle fuel injection system, and method for operating a pressure accumulator device of said type
AssigneeCPT Group GmbH
InventorsDaniel Anetsberger, Tet Kong Brian Chia, Walter Sassler
Life of this patent
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Abstract
An electrically driven solenoid coupled to a spring-operated valve, regulates pressure in an accumulator by opening when a predefined threshold pressure in a pressure accumulator is exceeded. The solenoid provides an assistive force to a spring-closed valve, reducing the amount of pressure required to open the valve responsive to the amount of current provided to the solenoid. The threshold pressure at which the valve opens is thus determined by the amount of current provided to the solenoid. Increasing the current decreases the threshold pressure; decreasing the current increases the threshold pressure.
Claims7
A method for operating a pressure accumulator device for a motor vehicle fuel injection system, the method comprising:
- applying fuel at a high pressure, to a pressure accumulator, by a fuel pump;
- removing pressure from the accumulator by a controllable, pressure reduction valve, the controllable pressure reduction valve comprising a solenoid-operated valve, configured to open responsive to an applied pressure, the applied pressure at which the solenoid-operated valve opens being determined by an amount of current provided to a solenoid coil of the solenoid-operated valve;
- automatically opening the pressure reduction valve in the event of a predetermined threshold pressure in the pressure accumulator being exceeded;
- checking pressure regulation of the pressure accumulator, comprising increasing the threshold pressure of the pressure reduction valve, determining whether fluid pressure in the pressure accumulator changes following increasing the threshold pressure of the pressure reduction valve, and determining whether a fault exists in the pressure regulation of the pressure accumulator based upon determining whether the fluid pressure in the pressure accumulator changes, wherein determining whether a fault exists determines a fault selected from the group comprising the pressure accumulator exceeding the predetermined threshold pressure thereof, and at least one of a leak and inefficient operation of the fuel pump existing;
- and
- prior to checking the pressure regulation of the pressure accumulator, monitoring the fluid pressure in the pressure accumulator;
- comparing the monitored pressure with a predetermined setpoint pressure;
- and comparing a difference between the fluid pressure and the setpoint pressure with a difference threshold value, wherein the checking of the pressure regulation of the pressure accumulator is performed responsive to the differential threshold value being exceeded.
Dependencies are inferred from the claim text.