A high-pressure fuel pump has an inlet valve and a pressure-limiting valve which fluidically connects a high-pressure region to an inlet valve region located, in terms of geometry, between the inlet valve and an electromagnetic actuator of the high-pressure fuel pump, which acts upon the inlet valve via a tappet.

The disclosure relates to a control method for controlling at least one injector valve in a fuel injection system of an internal combustion engine. An opening time of the injector valve is selected such that, in a fault situation in the fuel injection system, an opening time of the injector valve is situated in a pressure valley of a pressure oscillation prevailing in a high-pressure region of the fuel injection system.

An automotive fuel pump having a body with an inlet, an outlet, and an elongated chamber therebetween. A relief valve, relief valve housing, and check valve are respectively disposed in the chamber between the inlet and the outlet. The relief valve housing has a portion which extends across the chamber so that a first axial end of the relief valve housing forms a valve seat for the check valve while the other axial end forms a valve seat for the relief valve. The check valve permits fluid flow from the body chamber to the outlet while the relief valve exhausts excess fluid pressure at the outlet back into the body chamber.

Embodiments relate to an operating method for operating a fuel injection system of an internal combustion engine, wherein, upon a detection of a fault in the fuel injection system, and wherein a predefined pressure is overshot in a high-pressure region of the fuel injection system, an overrun mode of the internal combustion engine is deactivated, such that the internal combustion engine is operated exclusively in an injection mode.

In a high-pressure pump, a relief valve main body has a rod shape. A relief valve seat portion is integrated with an end of a relief valve main body so as to be capable of contacting a relief valve seat. The relief valve main body is inserted into a guide hole portion of a support portion. The guide hole portion slidably supports an outer wall of the relief valve main body so as to guide a reciprocating movement of the relief valve main body in the axial direction. A fuel guide portion is provided at an end portion of the relief valve main body facing the pressurizing chamber and can guide a flow of the fuel in a direction radially outward of the relief valve main body on the way from the pressurizing chamber toward the valve seat portion.

A pressure limiting valve for a fuel injection system may include a sleeve, a fixing pin, a spring, a sealing element, and a seat. The sleeve may have a longitudinal axis. The fixing pin protruding through a cavity enclosed by the sleeve. The spring may have a first end supported on the sleeve and a second end supported by the sealing element. The seat may provide a sealing surface for the sealing element to block a fluid flow through the valve when closed position, and allow this flow to pass in other positions. The outer circumference of the sleeve may vary within predefined tolerances along the longitudinal axis. The fixing pin may be shaped to plastically deform by a movement of the fixing pin along the longitudinal axis, in order to press the sleeve into the housing.

An engine fuel system includes a fuel delivery system including a first fuel pump that is coupled to a pressure relief valve that is arranged in parallel with a second fuel pump. The first fuel pump is disposed to deliver pressurized fuel to the second fuel pump and the pressure relief valve, and the second fuel pump is disposed to deliver pressurized fuel to the fuel rail. A controller characterizes the first fuel pump to determine a relationship between a fuel pump speed and a fuel pump current at a setpoint pressure for the pressure relief valve. A feed-forward pump speed command is determined based upon a target fuel pressure and a fuel flowrate. A closed-loop pump speed is commanded based upon the characterization of the fuel pump. The first fuel pump is controlled to deliver fuel to the second fuel pump based thereon.

Methods and systems are provided for adjusting operation of fuel injectors of an internal combustion engine to reduce injector ticking noise during direct injection fuel rail pressure release. The method includes first reducing a significant part of the direct injection fuel rail pressure via a mechanical high pressure pump relief valve and only if further pressure relief is required then intermittently activating the direct injector to inject in small amount of fuel. Due to the reduced frequency of activation and small pulse-widths, the impact force transmitted from injectors to cylinder head is small thereby reducing the objectionable ticking noise.

A fuel injection system for a reciprocating engine, comprising injectors for injecting pressurized fuel into the cylinders of the engine, a high pressure pump for pressurizing fuel to be injected, a supply pipe for feeding fuel from the high pressure pump toward the injectors and feed pipes for feeding fuel from the supply pipe to the injectors. The first ends of the feed pipes are connected to the injectors and the second ends to the supply pipe. Each fuel injector is provided with a pressure accumulator.

A valve (4, 4) for a fuel system for a combustion engine: A ball retainer (26) is provided with a cavity (28) to accommodate a ball (22). The ball (22) has a first seal surface (30) to cooperate with and abut sealingly against a seat (32). The ball retainer (26) has a secondary seal surface (34) to cooperate with and abut sealingly against the seat (32) when the ball (22) is not in the ball retainer (26). Also, a method for controlling a fuel system for a combustion engine.