US 12,253,055 B2
High-pressure fuel pump
Thomas Froihofer, Brackenheim (DE); Rainer Kornhaas, Stuttgart (DE); Guido Bredenfeld, Friedrichshafen (DE); and Stephan Wehr, Heiligenstadt (DE)
Assigned to Robert Bosch GmbH, Stuttgart (DE)
Appl. No. 18/291,719
Filed by Robert Bosch GmbH, Stuttgart (DE)
PCT Filed Jun. 8, 2022, PCT No. PCT/EP2022/065458
§ 371(c)(1), (2) Date Jan. 24, 2024,
PCT Pub. No. WO2023/006285, PCT Pub. Date Feb. 2, 2023.
Claims priority of application No. 10 2021 208 052.9 (DE), filed on Jul. 27, 2021.
Prior Publication US 2024/0344493 A1, Oct. 17, 2024
Int. Cl. F02M 59/46 (2006.01); F02M 63/00 (2006.01)
CPC F02M 59/46 (2013.01) [F02M 63/005 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A high-pressure fuel pump for a fuel system for an internal combustion engine, the high-pressure fuel pump comprising:
an inlet for supplying fuel;
an outlet for discharging compressed fuel;
a pump housing;
a delivery chamber which is disposed in the pump housing;
a pump piston which can be displaced in the pump housing along a longitudinal direction and delimits the delivery chamber;
an inlet valve, which is disposed between the inlet and the delivery chamber and which opens towards the delivery chamber;
an outlet valve, which is disposed between the delivery chamber and the outlet and which opens away from the delivery chamber;
an electromagnetic actuator, which acts on the inlet valve via a tappet;
a high-pressure region, which extends fluidically between the outlet valve and the outlet;
a low-pressure region, which extends fluidically between the inlet and the inlet valve; and
a pressure-limiting valve, which fluidically connects the high-pressure region to the low-pressure region and opens towards the low-pressure region, the pressure-limiting valve configured such that, when a pressure difference between fuel in the high-pressure region and fuel in the low-pressure region exceeds an opening pressure, the pressure-limiting valve opens towards an inlet valve region of the low-pressure region so as to fluidly connect the high-pressure region to the inlet valve region and enable fuel to flow out of the high-pressure region into the inlet valve region,
wherein:
the inlet valve region of the low-pressure region is geometrically located between the inlet valve and the electromagnetic actuator,
the outlet valve is fixed in an outlet valve bore of the pump housing,
the pressure-limiting valve is fixed in a pressure-limiting valve bore of the pump housing, and
the pressure-limiting valve bore is connected to the inlet valve region through a low-pressure connection bore located in the low-pressure region that extends from the inlet valve region to the low-pressure connection bore.