High-pressure fuel pump

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;
• delivery chamber disposed in the pump housing;
• a pump piston, which is displaceable in the pump housing along a longitudinal direction and which 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, the outlet valve opening away from the delivery chamber;
• 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 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 fluidically connects the high-pressure region to the low-pressure region and opens towards the low-pressure region to enable fuel to flow out of the high-pressure region into the low-pressure region,
• wherein the outlet valve is disposed in an outlet valve bore of the pump housing and the pressure-limiting valve is disposed in a pressure-limiting valve bore of the pump housing,
• wherein the inlet is formed as an inlet port fixed to the pump housing and an inlet port chamber of the low-pressure region is formed between the pump housing and the inlet port,
• wherein the pressure-limiting valve fluidically connects the high-pressure region to the inlet port chamber of the low-pressure region and opens towards the inlet port chamber, such that fuel flows out of the high-pressure region into the inlet port chamber when the pressure difference between fuel in the high-pressure region and fuel in the low-pressure region exceeds the opening pressure,
• wherein the pressure-limiting valve bore and the outlet valve bore are oriented geometrically parallel to each other, and
• wherein a low-pressure connection bore extends from the inlet port chamber of the low-pressure region to the pressure-limiting valve bore unidirectionally in a direction parallel with the inlet port.