The present disclosure relates to internal combustion engines. Various embodiments may include a fuel injection system for an internal combustion engine comprising: a high-pressure fuel pump with a pressure chamber and a pump piston; a high-pressure region downstream of the pump piston; and a valve arrangement connecting the pressure chamber to the high-pressure region. The valve arrangement includes an outlet valve and a pressure-limiting valve. The outlet valve and the pressure-limiting valve are mounted in two separate receptacle bores in a common valve housing. The receptacle bores extend along a longitudinal axis of the valve housing. The valve housing defines a central flow bore. The receptacle bores are each fluidly connected to the central flow bore by a bore intersection.

A fuel injector for an internal combustion engine is disclosed. The fuel injector is particularly suitable for use as a dual fuel injector, and comprises a generally tubular outer valve needle, an inner valve needle slidably received in the outer valve needle, and a nozzle body assembly comprising a tip part and a needle guide part. The tip part defines a seating region for the outer valve needle, and the needle guide part comprises a guide bore for slidably receiving the outer valve needle. In one embodiment, a lower bore region of the needle guide part defines a. cavity around the outer valve needle which houses a biasing spring for the outer valve needle and a fuel. A collar for seating the biasing spring can be dimensioned to allow free flow of the fuel from the cavity into an annular accumulator volume defined between the outer valve needle and the bore of the tip part.

A high-pressure fuel supply pump including an electromagnetically driven intake valve is configured such that a pressure equalizing hole is provided in the valve stopper positioned between the valve and a pressurizing chamber. The pressure equalization hole connects a spring storage space, provided between a valve and a valve stopper, with a surrounding fluid passage. The high-pressure fuel supply pump is further configured such that an opening of the pressure equalizing hole at the spring storage chamber side is open at a position at the inner side of a diameter of the spring. Since the pressure in the pressurizing chamber can be introduced into the inner side of the spring without traversing the spring, the unstable behavior of the spring or the valve due to the introduced pressure eliminated. Since the force applied to the valve when the valve closes is stabilized, the closing timing of the valve is stable.

The invention relates to a fuel injector, in particular a common-rail injector (1), comprising an injector housing (2), in which a nozzle needle (8), which is arranged in such a way that the nozzle needle can be moved in a reciprocating manner, is arranged in a high-pressure chamber (6) in order to open and close at least one injection opening (5), which nozzle needle bounds a control chamber (20) by means of one end face and interacts with a nozzle body seat (10) by means of the other end face in order to open and close the injection opening (5). The nozzle needle (8) has a first sleeve-shaped supporting element (14), to which force is applied in the closing direction of the nozzle needle (8). In addition, the nozzle needle (8) has a second sleeve-shaped supporting element, which surrounds the nozzle needle (8) and which is arranged in the direction of the end face of the nozzle needle (8) that is close to the control chamber. The second supporting element (16) is arranged at a distance from the first supporting element (14) axially in the closing direction of the nozzle needle (8). At least one of the stop surfaces (33, 34) of the first (14) sleeve-shaped supporting element or of the second (16) sleeve-shaped supporting element that face each other has at least one cut-out (36).

A mobile valve member designed to be arranged in the nozzle body of a fuel injector, extends along a main axis and includes a piston formed of a first male cylinder of effective diameter forming the top end of the mobile member and of a second cylinder provided with an internal cylindrical bore of the effective diameter and a shutoff member including a male cylindrical shaft of the effective diameter that fits slidingly in the internal bore, and of a member extending as far as a pointed end provided with a mobile seat and forming the bottom end of the mobile member. The mobile member is hydraulically balanced and the length between the top end and the bottom end thereof is variable as a result of the sliding of the cylindrical shaft in the internal bore of the piston.

The present disclosure relates to fluid injection valves. Various embodiments may include a valve assembly for a fluid injection valve and a fluid injection valve including: a valve body with a longitudinal axis; a valve needle; and a preloaded calibration spring for biasing the valve needle. The calibration spring is preloaded by press-fitting a fixing region of the calibration spring with a fixing element, wherein the fixing region of the calibration spring extends from the upper part. The calibration spring comprises an adjustment cap arranged around the upper part of the spring element and press-fitted with the fixing element. A circumferential side wall of the adjustment cap provides the fixing region.

A fuel injector (100) for an internal combustion engine is disclosed. The fuel injector is particularly suitable for use as a dual fuel injector, and comprises a generally tubular outer valve needle (130), an inner valve needle (140) slidably received in the outer valve needle (130), and a nozzle body assembly (112) comprising a tip part (120) and a needle guide part (118). The tip part (120) defines a seating region (120f) for the outer valve needle (130), and the needle guide part (118) comprises a guide bore (118e) for slidably receiving the outer valve needle (130). In one embodiment, the tip part (120) and the needle guide part (118) are made from different materials, and a biasing spring (148) for the outer valve needle (130) is housed in the nozzle body assembly (112).

A fuel pump system of a hybrid vehicle is provided. The fuel pump system prevents a fuel pump from continuing to operate when fuel is exhausted, whereby the fuel pump may be damaged. The pressure of fuel is measured in response to exhaustion of fuel, and when the pressure of fuel is low, fuel is circulated within the fuel pump instead of being supplied to the engine side, thereby preventing the fuel pump from being stuck due to frictional heat

A fuel pump system of a hybrid vehicle is provided. The fuel pump system prevents a fuel pump from continuing to operate when fuel is exhausted, whereby the fuel pump may be damaged. The pressure of fuel is measured in response to exhaustion of fuel, and when the pressure of fuel is low, fuel is circulated within the fuel pump instead of being supplied to the engine side, thereby preventing the fuel pump from being stuck due to frictional heat

The present disclosure relates to an injection valve. The valve may comprise a fluid inlet tube with a recess, a valve body, a valve needle, a spring element, and an elastic body. The valve body may have a central longitudinal axis and a cavity with a fluid outlet portion. The valve needle may be arranged in the recess of the fluid inlet tube and movable in the cavity. The spring element and elastic body may be arranged in the recess and interact with a portion of the valve body on one side and with a spring rest fixed to the valve needle on another side. The elastic body and the spring element are compressed as the valve needle is moved along the longitudinal axis away from its closing position. The elastic body, in the presence of a fluid pressure in the recess, exerts a fluid-pressure-dependent longitudinal force on the valve needle.