In a high-pressure pump, a relief valve seating surrounds an opening of a relief valve passage of a valve seat main body in a first space, A relief valve member includes a relief valve main body and a relief valve seat portion. The relief valve main body has a rod shape. The relief valve seat portion is integrated with an end of the relief valve main body so as to be capable of contacting the relief valve seat. The relief valve urging member urges the relief valve member toward the relief valve seat. A support portion includes a support main body that slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve member in the axial direction.

In a high-pressure pump, a relief valve seating surrounds an opening of a relief valve passage of a valve seat main body in a first space, A relief valve member includes a relief valve main body and a relief valve seat portion. The relief valve main body has a rod shape. The relief valve seat portion is integrated with an end of the relief valve main body so as to be capable of contacting the relief valve seat. The relief valve urging member urges the relief valve member toward the relief valve seat. A support portion includes a support main body that slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve member in the axial direction.

A relief valve device includes: a valve housing that includes a communication passage, which communicates between a first pressure chamber and a second pressure chamber, and a relief chamber, which is configured to communicate with the second pressure chamber; a partition wall that is formed in an inside of the valve housing and partitions between the communication passage and the relief chamber; a first valve member that is configured to block and enable flow of fluid between the first pressure chamber and the communication passage; a first urging member that urges the first valve member; a second valve member that is configured to block and enable flow of the fluid between the second pressure chamber and the relief chamber; and a second urging member that urges the second valve member.

A relief valve device includes: a valve housing that includes a communication passage, which communicates between a first pressure chamber and a second pressure chamber, and a relief chamber, which is configured to communicate with the second pressure chamber; a partition wall that is formed in an inside of the valve housing and partitions between the communication passage and the relief chamber; a first valve member that is configured to block and enable flow of fluid between the first pressure chamber and the communication passage; a first urging member that urges the first valve member; a second valve member that is configured to block and enable flow of the fluid between the second pressure chamber and the relief chamber; and a second urging member that urges the second valve member.

In a high-pressure pump, a relief valve seat surrounds an opening of a relief valve passage of a valve seat main body in a first space. A relief valve member includes a relief valve main body and a relief valve seat portion. The relief valve main body has a rod shape. The relief valve seat portion is integrated with an end of the relief valve main body so as to be capable of contacting the relief valve seat. The relief valve member is provided in the first space so as to be reciprocable in an axial direction. A relief valve urging member urges the relief valve member toward the relief valve seat. A support portion includes a support main body that slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve member in the axial direction.

In a high-pressure pump, a relief valve seat surrounds an opening of a relief valve passage of a valve seat main body in a first space. A relief valve member includes a relief valve main body and a relief valve seat portion. The relief valve main body has a rod shape. The relief valve seat portion is integrated with an end of the relief valve main body so as to be capable of contacting the relief valve seat. The relief valve member is provided in the first space so as to be reciprocable in an axial direction. A relief valve urging member urges the relief valve member toward the relief valve seat. A support portion includes a support main body that slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve member in the axial direction.

Low-cost fuel injection systems for internal combustion engines, including vapor fuel engines are provided.

A unit for regulating or controlling a fluid pressure of a fluid has a housing with at least one housing part and an inlet and an outlet for the fluid. A switching film is connected to the housing part and switches at pressure differences of 1 to 250 mbar relative to an ambient pressure acting on the switching film. The switching film regulates, releases or blocks a flow of the fluid between the inlet and the outlet for the fluid. The switching film is made of thermoplastic synthetic material. An opening cross section of the housing part is closed off by the switching film. In a method for fluid-tightly connecting a switching film to a housing part of the unit, a radial outwardly positioned joining region of the switching film is fluid-tightly pressed against the housing part in the region of joining surface.

A unit for regulating or controlling a fluid pressure of a fluid has a housing with at least one housing part and an inlet and an outlet for the fluid. A switching film is connected to the housing part and switches at pressure differences of 1 to 250 mbar relative to an ambient pressure acting on the switching film. The switching film regulates, releases or blocks a flow of the fluid between the inlet and the outlet for the fluid. The switching film is made of thermoplastic synthetic material. An opening cross section of the housing part is closed off by the switching film. In a method for fluid-tightly connecting a switching film to a housing part of the unit, a radial outwardly positioned joining region of the switching film is fluid-tightly pressed against the housing part in the region of joining surface.

A valve member is movable with first and second partition member and opens and closes a first pressure chamber with respect to a return passage. The first partition member partitions the first pressure chamber from a second pressure chamber. The second partition member partitions the second pressure chamber from a third pressure chamber. The first, second, and third pressure chambers cause fuel from a fuel flow passage to flow therethrough. A switching unit switches an opening and closing state of the second pressure chamber and the third pressure chamber with respect to the fuel flow passage and the return passage.