Disclosed herein are devices, systems, and methods relating to high-pressure fuel pump designs and features. A high-pressure fuel pump assembly includes a body, a camshaft, and an embossment. The body has a forward end and a rearward end opposite thereof and configured to couple to a low-pressure fuel pump. The camshaft is received and secured within a central bore of the body so as to be rotationally movable within the central bore. A coupler end of the camshaft is configured to couple to a drive shaft of the low-pressure fuel pump. The embossment includes at least one fastener boss configured to receive a fastener to couple the low-pressure fuel pump to the high-pressure fuel pump assembly. The embossment is formed at the rearward end of the body such that thermal stresses that cause geometrical deformations at the embossment are reduced through a range of engine temperature operating conditions.

A plunger is provided for reciprocating inside the barrel of a fuel pump. The plunger has a proximal end and a distal end. The proximal end of the plunger includes a cavity that defines a depressed volume within the plunger. A volume filler is disposed in the cavity, where the volume filler is constrained in the cavity by a retaining element.

A plunger is provided for reciprocating inside the barrel of a fuel pump. The plunger has a proximal end and a distal end. The proximal end of the plunger includes a cavity that defines a depressed volume within the plunger. A volume filler is disposed in the cavity, where the volume filler is constrained in the cavity by a retaining element.

A high pressure fuel pump includes: a pump body that forms a suction passage and a pressurizing chamber and slidably supports a plunger; and a control valve that opens a connection between the suction passage and the pressurizing chamber in a suction stroke, during which the plunger is driven toward a suction side for suctioning fuel into the pressurizing chamber, while the control valve controls closing timing, at which the connection between the suction passage and the pressurizing chamber is closed by the control valve in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber. The pump body forms a release passage that is communicated with the suction passage. The release passage relieves the fuel, which is pressurized by the plunger, from the pressurizing chamber before the closing timing during the delivery stroke.

A high pressure fuel pump includes: a pump body that forms a suction passage and a pressurizing chamber and slidably supports a plunger; and a control valve that opens a connection between the suction passage and the pressurizing chamber in a suction stroke, during which the plunger is driven toward a suction side for suctioning fuel into the pressurizing chamber, while the control valve controls closing timing, at which the connection between the suction passage and the pressurizing chamber is closed by the control valve in a delivery stroke, during which the plunger is driven toward a delivery side for delivering the fuel out of the pressurizing chamber. The pump body forms a release passage that is communicated with the suction passage. The release passage relieves the fuel, which is pressurized by the plunger, from the pressurizing chamber before the closing timing during the delivery stroke.

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.

A fuel pump module for a vehicle, which is formed in a low-floor type fuel pump module capable of being easily installed in a fuel tank with a reduced vertical height. The fuel pump module includes a head plate to be mounted in an opening of a fuel tank, a reservoir cup to which the head plate is pivotably coupled through a pair of connecting bars and which is to be installed in the fuel tank in a state of being coupled to the head plate, a fuel pump disposed in the reservoir cup in a state of being laid and to deliver fuel in the reservoir cup to an outside of the fuel tank, and a jet pump installed in the reservoir cup and to suction fuel outside the reservoir cup and discharge the fuel into the reservoir cup.

A fuel pump module for a vehicle, which is formed in a low-floor type fuel pump module capable of being easily installed in a fuel tank with a reduced vertical height. The fuel pump module includes a head plate to be mounted in an opening of a fuel tank, a reservoir cup to which the head plate is pivotably coupled through a pair of connecting bars and which is to be installed in the fuel tank in a state of being coupled to the head plate, a fuel pump disposed in the reservoir cup in a state of being laid and to deliver fuel in the reservoir cup to an outside of the fuel tank, and a jet pump installed in the reservoir cup and to suction fuel outside the reservoir cup and discharge the fuel into the reservoir cup.

A high pressure fuel pump includes (i) a pump housing, (ii) a pump piston, (iii) a high pressure seal which is disposed between the pump piston and the pump housing and seals the pump piston with respect to a high pressure region, and (iv) an annular guide element which guides the pump piston in a sliding fit and which is disposed towards the high pressure region when seen from the high pressure seal. The annular guide element has at least one fluid connection which fluidically connects a first region to a second region. The first region is adjacent to a first end face of the guide element. And the second region is adjacent to a second end face of the guide element.

A seal ring is in contact with an outer peripheral surface of a plunger. A biasing ring is made of a material having a lower fuel resistance than the seal ring, and is provided radially outwardly with respect to the seal ring in a seal chamber so as to bias the seal ring against the plunger. An axial position of a portion of the seal ring where a surface pressure on the plunger is maximum is defined as a maximum surface pressure position. The seal ring has diameter changing portions in both axial directions with respect to the maximum surface pressure position. The diameter changing portions are formed so as to have an outer diameter smaller than that of the portion corresponding to the maximum surface pressure position.