US 11,852,094 B2
Fuel pressure control system
Takahiro Kondo, Kariya (JP); and Ryohei Sano, Kariya (JP)
Assigned to DENSO CORPORATION, Kariya (JP)
Filed by DENSO CORPORATION, Kariya (JP)
Filed on May 2, 2023, as Appl. No. 18/310,990.
Application 18/310,990 is a continuation of application No. PCT/JP2021/037589, filed on Oct. 11, 2021.
Claims priority of application No. 2020-184739 (JP), filed on Nov. 4, 2020.
Prior Publication US 2023/0272757 A1, Aug. 31, 2023
Int. Cl. F02D 41/22 (2006.01); F02D 1/02 (2006.01); F02M 59/46 (2006.01)
CPC F02D 41/22 (2013.01) [F02D 1/02 (2013.01); F02M 59/46 (2013.01); F02D 2041/226 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A fuel pressure control system for a fuel supply system that supplies fuel to an injector of an engine, the fuel pressure control system comprising:
a booster pump for increasing a high-pressure system fuel pressure as a fuel pressure of a high-pressure system as a part of the fuel supply system by discharging the fuel to the high-pressure system;
a pressure reducing valve for reducing the high-pressure system fuel pressure; and
a control device for controlling the booster pump and the pressure reducing valve, wherein:
the control device includes a valve opening necessity determination unit for determining whether the pressure reducing valve needs to be opened;
the control device executes a valve opening control for opening the pressure reducing valve to release the high-pressure system fuel pressure to an outside of the high-pressure system under a condition that the valve opening necessity determination unit determines that the pressure reducing valve needs to be opened;
the control device further includes a restriction execution unit for performing a valve opening restriction control in the valve opening control for opening the pressure reducing valve with restricting a valve opening degree of the pressure reducing valve to prevent a pressure exceeding a predetermined target portion threshold pressure from being applied to a target portion as a release destination or a release passage of the high-pressure system fuel pressure in the valve opening control;
the control device further includes a protection necessity determination unit that determines whether it is in a protection-required state as a predetermined state in which there is a risk that the pressure exceeding the target portion threshold pressure is applied to the target portion unless the valve opening restriction control is executed in the valve opening control;
the control device executes a normal valve opening control in the valve opening control without performing the valve opening restriction control when the valve opening necessity determination unit determines that the pressure reducing valve needs to be opened and the protection necessity determination unit determines that it is not in the protection-required state; and
the control device executes the valve opening restriction control using the restriction execution unit to restrict the valve opening degree of the pressure reducing valve compared to a case where the valve opening restriction control is not executed when the valve opening necessity determination unit determines that the pressure reducing valve needs to be opened and the protection necessity determination unit determines that it is in the protection-required state.