A high-pressure pump includes a pressurizing chamber forming portion, a suction passage forming portion, a seat member, a valve member, a cylindrical member, a needle, a movable core, a biasing member, a fixed core, and a coil including a winding portion. The coil generates an attractive force between the fixed core and the movable core when the winding portion is energized. The coil includes an outer cylindrical surface and multiple inner cylindrical surfaces that have different diameters. The multiple inner cylindrical surfaces are arranged in order of increasing diameter in a direction toward a pressurizing chamber. The movable core has an end surface that faces the fixed core, and the end surface of the movable core is located between a center, in an axial direction, of a smallest diameter one of the plurality of inner cylindrical surfaces and a center, in an axial direction, of the outer cylindrical surface.

A communication port opens at a shifted position of a fuel passage that is positionally shifted from an inside residual pressure holding valve toward an outside residual pressure holding valve. The fuel passage includes an outside passage part through which the fuel to be discharged into an internal-combustion engine flows from the communication port toward the outside residual pressure holding valve, and an inside passage part that throttles a flow of fuel flowing from the communication port toward the inside residual pressure holding valve more than the outside passage part. When a passage cross-sectional area of the inside passage part is converted into a passage cross-sectional area of a circular pipe, D which is a passage diameter of the circular pipe, and L which is a length of the inside passage part satisfy a relational expression of L/D≧3.

There is provided a damper unit that allows a plurality of damper bodies to be installed by simple work. The damper unit includes at least two damper bodies that are installed in a housing space so as to be stacked and include hermetically sealed spaces therein. The damper unit further an elastic member 7 that is disposed between the damper bodies, and a stopper that is installed across outer peripheral edge portions of the damper bodies positioned at both ends.

A high-pressure pump includes a pressurizing chamber forming portion, a suction passage forming portion, a seat member, a valve member, a cylindrical member, a needle, a movable core, a biasing member, a fixed core, and a coil including a winding portion. The coil generates an attractive force between the fixed core and the movable core when the winding portion is energized. The coil includes an outer cylindrical surface and multiple inner cylindrical surfaces that have different diameters. The multiple inner cylindrical surfaces are arranged in order of increasing diameter in a direction toward a pressurizing chamber. The movable core has an end surface that faces the fixed core, and the end surface of the movable core is located between a center, in an axial direction, of a smallest diameter one of the plurality of inner cylindrical surfaces and a center, in an axial direction, of the outer cylindrical surface.

A pressure damping device for a fluid circuit includes a lower body having a fluid inlet port and a fluid outlet port. An upper cover attaches to the body. An elastically deformable membrane is interposed between the body and the cover, and a circular cup is arranged on the membrane. A spring is interposed between the cup and a bottom of the cover. The body includes a support member for supporting the membrane, with the support member projecting from the first bottom and including a free upper end on which the membrane is adapted to be supported.

A high-pressure fuel supply pump for a fuel system that supplies a high-pressure fuel injection (GDI) apparatus and a low-pressure fuel injection (PFI) apparatus incorporates an inlet check valve to isolate a low-pressure fuel feed channel in the pump from pressure fluctuations at the inlet of an inlet control valve. Upstream of the inlet check valve, the low-pressure fuel feed channel is connected to a seal chamber surrounding the pumping plunger. Circulating fresh low-pressure fuel through the seal chamber ensures that the pumping plunger and the clearance between the plunger and the pump bore are cooled and lubricated with fuel, even when high pressure fuel is not produced by the high-pressure pump. The low-pressure fuel feed channel is connected to the low-pressure PFI outlet downstream of the seal chamber. This pump configuration provides stable source of low-pressure fuel for a PFI system.

A high-pressure pump includes a pressurizing chamber forming portion, a suction passage forming portion, a seat member, a valve member, a cylindrical member, a needle, a movable core, a biasing member, a fixed core, and a coil including a winding portion. The coil generates an attractive force between the fixed core and the movable core when the winding portion is energized. The coil includes an outer cylindrical surface and multiple inner cylindrical surfaces that have different diameters. The multiple inner cylindrical surfaces are arranged in order of increasing diameter in a direction toward a pressurizing chamber. The movable core has an end surface that faces the fixed core, and the end surface of the movable core is located between a center, in an axial direction, of a smallest diameter one of the plurality of inner cylindrical surfaces and a center, in an axial direction, of the outer cylindrical surface.

A fuel system includes a low-pressure fuel delivery unit and a high-pressure fuel delivery unit which has a low-pressure region and a high-pressure region such that the low-pressure region supplies fuel to the high-pressure region which supplies the fuel to a plurality of high-pressure fuel injectors. A low-pressure fuel rail supplies fuel to low-pressure fuel injectors. A low-pressure fuel injector line is connected at a first end directly to the high-pressure fuel delivery unit and receives fuel from the low-pressure region and is connected at a second end directly to the low-pressure fuel rail, thereby providing fluid communication from the low-pressure region to the low-pressure fuel rail. A device is located between the low-pressure region and the low-pressure fuel rail and reduces fuel pressure pulsations.

A fuel supply device includes a fuel supply passage, a fuel pump, a pressure-regulating valve, and a housing. The fuel supply passage is in communication with the fuel injector. The fuel pump pumps the fuel to the fuel supply passage. The pressure-regulating valve regulates the pressure of the fuel in the fuel supply passage. The housing is disposed in the fuel tank. The housing accommodates the fuel pump and the pressure-regulating valve. The fuel supply passage is formed within the housing. The pressure-regulating valve is connected to an end portion of the fuel supply passage formed in the housing. The volume of the end portion of the fuel supply passage in the housing is configured to increase with increasing pressure of the fuel.

Provided is a metal diaphragm that can be easily processed and manufactured at low cost. Therefore, a metal diaphragm (91, 92) of the present invention is configured such that a curvature radius r1 of a first curved portion 911 located on the outermost side in the radial direction (outer side in the left-right direction in FIG. 5) is minimized among a flange portion (91a, 92a) and curved portions (911, 912) that are located on the radially inner side of the flange portion (91a, 92a) and curved from the flange portion (91a, 92a) to one side (upper side in FIG. 5).