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.

A high-pressure fuel pump includes a pump housing, a receiving space in the pump housing, a pressure pulsation damper in the form of a diaphragm cell having two diaphragms, which pressure pulsation damper is arranged in the receiving space, and a holding device for holding the diaphragm cell in the receiving space. The holding device includes a connection portion, which is connected to the pump housing rigidly both in an axial direction and in a radial direction. The connection portion is fastened to the pump housing, both in the axial direction and in the radial direction, to an inner lateral surface of the pump housing that delimits the receiving space.

A testing apparatus for a fuel injector includes an upper mount for receiving an inlet of the fuel injector; a lower mount located beneath the upper mount for receiving a nozzle end of the fuel injector; and at least one of a removable inlet adaptor and a removeable outlet adapter. The inlet of the fuel injector fits into the inlet adaptor to allow a flow of fluid to be delivered through the inlet adaptor to the fuel injector and removable from the upper mount. The removable outlet adaptor removable from the lower mount.

A pulse damper constructed in accordance to one example of the present disclosure includes a first housing member, a second housing member, a diaphragm and a valve. The first housing member defines a fuel chamber at an internal space thereof. The first housing member can further have a fuel inlet and a fuel outlet. The second housing member can define a pressurized chamber. The diaphragm can be disposed between the first and second housing. The diaphragm separates the fuel chamber and the pressurized chamber. The valve can be disposed on the second housing and be configured to selectively pass air into and out of the pressurized chamber corresponding to a desired predetermined pressure within the pressurized chamber. Increased pressure within the pressurized chamber will resist movement of the diaphragm into the pressurized chamber.

A fuel pump includes a housing, a pump section disposed within the housing on a first side thereof, a motor section disposed within the housing on a second side thereof and communicating with the pump section, and an upper body closing an end of the housing on the second side. A fuel chamber, into which fuel flows from the pump section through the motor section toward the second side of the housing, and a first branch fuel path, which is connected to the fuel chamber, are provided between the upper body and a motor. A discharge port is connected to the fuel chamber. A supply port is connected to the first branch fuel path, and the fuel in the fuel chamber is provided to the supply port through the first branch fuel path.

A diaphragm includes a flange and a protrusion provided to protrude to one side of the flange, wherein the protrusion has at least two annular curved portions provided annularly on a ceiling portion having a flat surface-like shape and an outer side in a radial direction of the ceiling portion, in a state where pressure on an outer wall side of the protrusion and pressure on an inner wall side of the protrusion are the same, the at least two annular curved portions are each formed to be curved in a cross-section of the diaphragm obtained by cutting the diaphragm by a virtual plane including a center line of the diaphragm, the centers of curvature of the curved portions being arranged at different positions on a side opposite to a protruding direction of the protrusion, and the diaphragm is formed of a sheet metal.

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.

A discharge valve of a high-pressure pump is placed in a discharge passage and is openable to enable flow of fuel from a pressurizing chamber to a discharge outlet in response to a fuel pressure difference between the pressurizing chamber side and the discharge outlet side. A relief is placed in a relief passage. The relief passage communicates between a branching portion, which is located on a side of the discharge valve where the discharge outlet is placed in the discharge passage, and a return portion, which merges with a damper chamber. The relief valve is openable to enable flow of the fuel from the branching portion to the return portion in response to a fuel pressure difference between the branching portion side and the return portion side. A discharge passage orifice is placed between the discharge valve and the branching portion in the discharge passage and constricts a flow passage cross-sectional area of the discharge passage.

When fuel injections into Otto-engines are carried out, pressure pulsations occur in the entire fuel injection system. These prevent detailed information about the fuel injection to be deduced from the pressure signals measurable in the system. When specially designed dampers for these pressure pulsations are employed, pressure difference signals over the pulsation damper can readily be employed for instantaneous volume flow rate measurements. Furthermore, the inserted pressure pulsation dampers also allow the pressure reduction in the Common-Rail, due to the fuel injections, to be employed to measure the instantaneous fuel injection volume flow rates, in running Otto-engines. The authors' development work in this field is described in this paper and results of verification measurements are presented.