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.

The invention relates to a pressure regulating valve for regulating pressure in a high-pressure fuel accumulator for an internal combustion engine, comprising a valve piston (5) accommodated axially displaceably in a bore (1) in a valve housing (2), acting on a valve closing member (3) in the direction of a valve seat (4), said valve piston being connected at the end thereof facing away from the valve seat (4) to an armature (6) of a magnetic assembly (7) for actuating the pressure regulating valve, wherein the armature (6) is accommodated in an armature chamber (8) and the valve closing member (3) is accommodated in a valve chamber (9). According to the invention, the valve chamber (9) and the armature chamber (8) are hydraulically connected via at least one groove (10) and/or bore (11) formed in the valve housing (2), valve piston (5) and/or in the armature (6), as well as at least one choke point (12).

A control device is applied for an internal combustion engine which is provided with a high-pressure fuel pump driven by a driving shaft of the internal combustion engine to discharge a fuel pressurized in a pressurizing chamber, an accumulator accumulating a high-pressure fuel discharged from the high-pressure fuel pump, and a relief valve which is opened when a fuel pressure in the accumulator is higher than a specified pressure in order to return the fuel in the accumulator to a specified chamber where a fuel has lower pressure than a fuel in the pressurizing chamber. An idle speed of the internal combustion engine is increased to a specified speed when the fuel pressure in the accumulator has been higher than a determination pressure, which is lower than the specified pressure, for a first period or longer.

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.

In a pressure regulator, a valve element nozzle is supported by a diaphragm, which partitions between an inlet portion and an outlet portion. The outlet portion includes an inner cover and an outer cover. The inner cover receives an adjusting spring in an inside space of the inner cover. A primary communication hole is formed in the inner cover to oppose the valve element nozzle, and a secondary communication hole is formed in the inner cover at a location, which is on a radially outer side of the primary communication hole. The outer cover covers the inner cover and thereby forms a fuel space, which is communicated with the inside space through the primary and secondary communication holes, at a location between the inner cover and the outer cover.

A high-pressure injection device for an internal combustion engine to which engine segment times are assigned, having a high-pressure pump, a rail connected to the high-pressure pump via a high-pressure fuel line, at least one injector, a digital pressure reduction valve connected to the rail, a fuel return line connected to the pressure reduction valve, and a control unit. The control unit is configured to switch the pressure reduction valve into the transmissive state only in predetermined engine segment times, and to maintain said transmissive state of the pressure reduction valve for a time period which is greater than the duration of one engine segment time.

A fuel pump has a low pressure fuel inlet (40) and a single piston pumping chamber (10) for supplying high pressure fuel through a pump outlet to an inlet side of a common rail (16). The fuel pump comprises a primary pressure relief valve (12) having an inlet side in hydraulic communication with the inlet side of the common rail (16) and an outlet side in fluid communication with the pumping chamber (10); and an auxiliary pressure relief valve (19) having an inlet side (35) in hydraulic communication with the pumping chamber (10) and an outlet side in direct fluid communication with a fuel passage (37) at the low pressure of the pump inlet (40).