A damper for a high-pressure pump includes a housing and a cover that can be coupled to the housing to form a damping space. The cover has an elevation including a plurality of concave regions and a plurality of convex regions, wherein the concave and convex regions are arranged about a central region of the elevation. Each of the concave regions is arranged between two of the convex regions in order to scatter sound.

An anti-reflection device for preventing the reflection of pressure waves inside a fuel injection valve. The anti-reflection device includes an essentially cylindrical base body with a first base side, a second base side, and an outer surface. The anti-reflection device also includes a longitudinal axis orientated parallel to a propagation direction of a pressure wave. The longitudinal axis penetrating the first base side and the second base side. The anti-reflection device also includes a flow path for fuel formed between the first base side and the second base side. The flow path forming a curve around the longitudinal axis.

An anti-reflection device for preventing the reflection of pressure waves inside a fuel injection valve. The anti-reflection device includes an essentially cylindrical base body with a first base side, a second base side, and an outer surface. The anti-reflection device also includes a longitudinal axis orientated parallel to a propagation direction of a pressure wave. The longitudinal axis penetrating the first base side and the second base side. The anti-reflection device also includes a flow path for fuel formed between the first base side and the second base side. The flow path forming a curve around the longitudinal axis.

A damper device arranged in a housing space formed between a device main body and a cover member includes a pair of damper bodies each having a plate and a diaphragm and having an enclosed space sealed with gas. A biasing device is provided between the pair of damper bodies arranged facing each other and configured to bias the damper bodies from one side of the device main body and the cover member to the other side of the device main body and the cover member, stay members each extending from an outer peripheral edge portion of each of the damper bodies and brought into contact with other side, and a frame member arranged on one side of the device main body and the cover member and having a stopper portion configured to restrict movement of the damper bodies in the direction of the other side.

A damper device arranged in a housing space formed between a device main body and a cover member includes a pair of damper bodies each having a plate and a diaphragm and having an enclosed space sealed with gas. A biasing device is provided between the pair of damper bodies arranged facing each other and configured to bias the damper bodies from one side of the device main body and the cover member to the other side of the device main body and the cover member, stay members each extending from an outer peripheral edge portion of each of the damper bodies and brought into contact with other side, and a frame member arranged on one side of the device main body and the cover member and having a stopper portion configured to restrict movement of the damper bodies in the direction of the other side.

A fuel supply device includes a sub-tank, a pump unit, a jet pump, and a connection structure connected with the pump unit and the jet pump. The connection structure has a guide part that is provided to the pump unit and guides the pressurized fuel toward the bottom in an axial direction, a pressurizing part that is provided to the jet pump and is fitted to the guide part from a side of the bottom in an axially slidable manner, to which the pressurized fuel is guided from the guide part, a shock-absorbing member that has a low spring constant that is predetermined and mitigates an axial impact between the guide part and the pressurizing part, and a sealing member that has a high spring constant higher than the low spring constant of the shock-absorbing member and radially seals a space between the guide part and the pressurizing part.

A fuel supply device includes a sub-tank, a pump unit, a jet pump, and a connection structure connected with the pump unit and the jet pump. The connection structure has a guide part that is provided to the pump unit and guides the pressurized fuel toward the bottom in an axial direction, a pressurizing part that is provided to the jet pump and is fitted to the guide part from a side of the bottom in an axially slidable manner, to which the pressurized fuel is guided from the guide part, a shock-absorbing member that has a low spring constant that is predetermined and mitigates an axial impact between the guide part and the pressurizing part, and a sealing member that has a high spring constant higher than the low spring constant of the shock-absorbing member and radially seals a space between the guide part and the pressurizing part.

A damper assembly of a high-pressure fuel pump for reducing fuel pulsation, which is capable of reducing the pulsation of a fuel transferred to the high-pressure fuel pump to stabilize the supply of the fuel, having a simplified structure to minimize an installation space and curtailing manufacturing costs, is provided. The damper assembly of the high-pressure fuel pump includes a damper including upper and lower bodies having flange portions formed along a circumference thereof to face each other in a vertical direction, a retainer ring including a curved portion configured to support the damper and a support portion extending from the curved portion in a longitudinal direction, and a cover member configured to surround the damper and the retainer ring. Here, the damper is fixed in a housing as the flange portion of the upper body, the flange portion of the lower body and the curved portion of the retainer ring are welded at welding portions at the same time.

A damper assembly of a high-pressure fuel pump for reducing fuel pulsation, which is capable of reducing the pulsation of a fuel transferred to the high-pressure fuel pump to stabilize the supply of the fuel, having a simplified structure to minimize an installation space and curtailing manufacturing costs, is provided. The damper assembly of the high-pressure fuel pump includes a damper including upper and lower bodies having flange portions formed along a circumference thereof to face each other in a vertical direction, a retainer ring including a curved portion configured to support the damper and a support portion extending from the curved portion in a longitudinal direction, and a cover member configured to surround the damper and the retainer ring. Here, the damper is fixed in a housing as the flange portion of the upper body, the flange portion of the lower body and the curved portion of the retainer ring are welded at welding portions at the same time.

An object of the present invention is to obtain a high pressure fuel supply pump capable of reducing pressure pulsation that occurs in a low pressure pipe, preventing damage to the low pressure pipe, or reducing noise due to vibrations of the low pressure pipe. The present invention provides a high pressure fuel supply pump of a type in which, from a fuel suction port connected to a low pressure pipe provided upstream of a fuel, a low pressure passage, an electromagnetic suction valve driven by an electromagnetic force, a pressurizing chamber in which the volume thereof is increased or reduced by a plunger that is reciprocatingly moved by being guided by a cylinder, and a discharge valve provided at an outlet of the pressurizing chamber are sequentially arranged, a fuel is sucked to the pressurizing chamber through the electromagnetic suction valve, the amount of a part of the fuel, which is sucked to the pressurizing chamber, to be returned to the low pressure passage side is adjusted so that the amount of the fuel to be discharged through the discharge valve is controlled, and the high pressure fuel supply pump includes a backflow suppression mechanism for suppressing backflow of fuel from the fuel from the fuel suction portion to the low pressure pipe side.