High-pressure fuel pump

A high-pressure fuel pump comprising:

• a pressurizing chamber which is formed in a pump body;
• an outlet valve device which is disposed on an outlet passage side of the pressurizing chamber;
• a relief valve device which is disposed in a relief passage fluidly connecting an outlet passage to the pressurizing chamber, while bypassing the outlet valve device, wherein
• the relief valve device includes a relief valve and a relief valve seat against which the relief valve abuts,
• the pressurizing chamber includes a top wall forming the top of the pressurizing chamber, the top wall including a bottom surface facing the pressurizing chamber and an opposing top surface facing away from the pressurizing chamber, wherein the relief valve seat is disposed within a recess formed in the top surface,
• the pump body defines a cavity into which the relief valve is inserted, the cavity having a first longitudinal end and a second longitudinal end that is opposite to the first longitudinal end, the second longitudinal end is located at an outermost surface of the pump body, and
• the relief valve opens along a direction that is away from the second longitudinal end of the cavity.

A high-pressure fuel pump comprising:

• a pressurizing chamber which is formed in a pump body;
• an outlet valve device which is disposed on an outlet passage side of the pressurizing chamber;
• a relief valve device which is disposed in a relief passage fluidly connecting an outlet passage to the pressurizing chamber, while bypassing the outlet valve device, wherein
• the relief valve device includes a relief valve, a relief valve seat, and a relief spring configured to pull the relief valve toward the relief valve seat,
• the relief valve device includes a holder welded to the relief valve seat, the holder containing the relief spring therein,
• the holder is fixed within a mounting hole formed in the pump body, the mounting hole opening directly to an inlet passage of the pump,
• the relief valve being disposed in the mounting hole, the mounting hole having a first longitudinal end and a second longitudinal end that is opposite to the first longitudinal end, the second longitudinal end is located at an outermost surface of the pump body, and
• the relief valve opens along a direction that is away from the second longitudinal end of the cavity.