A high-pressure fuel pump includes a pump housing, a pressurizing member, a suction valve seat, a suction valve body, and a suction valve chamber. The suction valve seat includes a first projected wall section that is projected to an upper side in a vertical direction. The pump housing includes a second projected wall section that is directed to the upper side in the vertical direction. A height of the lowest position in a portion of the second projected wall section that is projected to the upper side in the vertical direction is higher than a height of the lowest position in a portion of the first projected wall section that is projected to the upper side in the vertical direction. A first initial fuel pool is provided on an downstream side of the second projected wall section and on the upstream side of the suction valve seat.

A high-pressure fuel pump includes a pump body, a plunger, a retainer, a spring that is configured to energize the plunger in a direction opposite to a direction of the pressurizing chamber, and a tappet covering the retainer from a side of an end portion of the retainer and the plunger. The retainer is provided with a projection portion protruding to a side of the tappet. The projection portion is separated from the tappet by a predetermined distance along an axial direction of the plunger.

A high-pressure fuel pump includes a pump body, a plunger, a retainer, a spring that is configured to energize the plunger in a direction opposite to a direction of the pressurizing chamber, and a tappet covering the retainer from a side of an end portion of the retainer and the plunger. The retainer is provided with a projection portion protruding to a side of the tappet. The projection portion is separated from the tappet by a predetermined distance along an axial direction of the plunger.

A method for testing a high-pressure pump, particularly a high-pressure pump which is provided to inject fuel into a combustion engine, the method including filling the high-pressure pump with a fluid prior to switching it on.

A method for testing a high-pressure pump, particularly a high-pressure pump which is provided to inject fuel into a combustion engine, the method including filling the high-pressure pump with a fluid prior to switching it on.

A pump body of a high pressure fuel pump defines a compression chamber in fluid communication with a first recess dug in a first outer face. A second recess is dug in a second outer face of the body. An inlet channel opens in a conduit extending between the first recess and the second recess.

A metering valve supplies fuel to and block fuel from a pressurizing chamber by moving a valve body by switching between energization and de-energization of an electromagnetic unit. An energization control unit performs a valve closing control and a valve opening control to reduce operating sound in one opening and closing period in which the valve body opens and closes. A time control unit controls, on determination that the energizing period of the electromagnetic unit exceeds the upper limit value, a moving speed of the valve body when the valve body moves to a valve closing side, such that the energization period of the electromagnetic unit in the one opening and closing period does not exceed the upper limit value, thereby to cause the energization control unit to perform both the valve closing control and the valve opening control in the one opening and closing period.

To suppress the possibility that a body-side holding member comes into contact with a joint portion 92 of a damper mechanism 9. damper cover that is arranged on an upstream side of a pressurizing chamber and is attached to a body to form a damper chamber, a damper mechanism that is arranged in the damper chamber, and a body-side holding member that holds the damper mechanism from the body side are provided. The body-side holding member includes a bottom surface in contact with the body and a flexible portion formed along an urging direction by being urged downward from the damper cover toward the body.

To suppress the possibility that a body-side holding member comes into contact with a joint portion 92 of a damper mechanism 9. damper cover that is arranged on an upstream side of a pressurizing chamber and is attached to a body to form a damper chamber, a damper mechanism that is arranged in the damper chamber, and a body-side holding member that holds the damper mechanism from the body side are provided. The body-side holding member includes a bottom surface in contact with the body and a flexible portion formed along an urging direction by being urged downward from the damper cover toward the body.

A fuel pump for a liquid fuel water injection system of a motor vehicle is provided. The fuel pump includes a low-pressure pump that mixes water from a water tank of the motor vehicle with liquid fuel from a fuel tank of the motor vehicle to a liquid fuel water emulsion and provides the liquid fuel water emulsion at a low pressure. A high-pressure pump is in fluid communication with the low-pressure pump and compresses the liquid fuel water emulsion from the low pressure to a high pressure for injecting the liquid fuel water emulsion into an internal combustion engine of the motor vehicle via an injection rail of the motor vehicle. A pump drive drives the low-pressure pump and the high-pressure pump synchronously with a pump frequency independently from an engine speed of the internal combustion engine of the motor vehicle.