The fuel injection valve has a hydraulic control device for controlling the axial movement of the injection valve member. The stem of the intermediate valve member of mushroom-shaped configuration of the intermediate valve is guided in the guide recess of the intermediate part. In the open position, the intermediate valve member opens up a second connection between a high-pressure fuel inlet and a valve chamber and, in the closed position, the intermediate valve member shuts off the second connection between the high-pressure fuel inlet and the valve chamber. In the closed position of the intermediate valve member, the head of the intermediate valve member lies with a side facing toward the intermediate part against the intermediate valve seat via a first sealing surface, which runs around the stem or the guide recess at a first radial spacing so as to form a first annular sealing surface which is continuous in the circumferential direction.

Provided is a discharge valve mechanism capable of improving responsiveness when a discharge valve is opened, and a high-pressure fuel supply pump including the discharge valve mechanism.

A discharge valve mechanism 500 includes a valve seat portion 51 having a primary-side flow path, a valve body 52 which can be seated on and separated from the valve seat portion 51, and a guide portion 542a which is formed to be slidable on an outer surface of the valve body 52 and guides movement of the valve body 52 in a contacting/separating direction with respect to the valve seat portion 51. The guide portion 542a includes a portion in which a gap from the outer surface of the valve body 52 is set to a predetermined value or less. A first secondary-side flow path 545 which allows an internal space 541a on an upstream side of the guide portion 542a to communicate with an external flow path 2g is formed to allow the fluid to flow out to a side in a moving direction of the valve body 52, and a second secondary-side flow path 546 which allows an internal space 543a on a downstream side of the guide portion 542a to communicate with the external flow path 2g is formed to allow the fluid to flow out to the side in the moving direction of the valve body 52.

A fuel cell system is provided having a fuel cell and a jet pump control valve unit connected to an anode chamber with an intake connection and a pressure connection. A fuel gas control valve connecting a fuel gas source and the jet pump has a valve seat with a first sealing surface and at least two through-flow channels, and a moveable valve body with a second sealing surface. The valve body can be moved into a blocking position and a through-flow position using a valve body actuator. The sealing surfaces rest on one another in a common sealing plane and form a seal in the blocking position. A stroke gap is formed between the sealing surfaces in the through-flow position. The first or second sealing surface is arranged on a raised sealing level. A volume flow of a drive jet can be controlled by the valve body actuator.

A valve assembly for a fluid injection valve has a longitudinal axis and includes a valve seat and a valve disc. The valve seat has an orifice that is laterally offset from the longitudinal axis. The valve disc has a fluid passage which, in a first angular position of the valve disc, is positioned in such fashion that it overlaps the orifice at an interface of the valve disc and the valve seat to establish a fluid path through the valve disc and the valve seat for dispensing fluid from the valve assembly. The valve disc is rotatable around the longitudinal axis with respect to the valve seat from the first angular position to a second angular position, wherein the valve seat and the valve disc mechanically interact to seal the orifice in the second angular position.

The invention relates to a pressure regulator for a high-pressure ramp of a system for injecting fuel into an internal combustion engine, comprising a solenoid valve element (10) which receives an electromagnet (40). The electromagnet controls a needle (20) that closes a valve seat (30) which is connected to a high-pressure inlet and opens into a discharge chamber (13), said discharge chamber communicating with a liquid recirculation system (5) by means of outlet openings (14). The rear face (12) of the solenoid valve element (10) receives a coil (40) which controls the opening process of an armature (41) that is rigidly connected to the needle (20) and is subject to a closing return spring (25). The discharge chamber (13) is located on the front face (11) of the solenoid valve element (10) on the axis (XX) of the needle (20), and the discharge chamber surrounds the needle. A cavity (15) passes through the discharge chamber, said cavity receiving an inlet valve element (50), and a bore (51) which opens into the valve seat (30) passes axially through the inlet valve element. The discharge chamber (13) through which the needle (20) passes axially and the outlet openings (14) which are connected to the liquid recirculation system open transversally into a wall (131) in the discharge chamber (13) .sub.in below the upper part (132) of the chamber. The regulator is characterized that the regulator comprises an annular expansion (70) of the discharge chamber (13) below the outlet openings (14) along the extension of a conical surface (31), which forms the valve seat (30) and an annular dead volume (70), above the surface (54) of the valve element (50), which forms the base of the discharge chamber (13) and has the valve seat (30) in the center of the valve element.

A fuel injector nozzle assembly includes a two-piece outlet check having a timing control piece and a rate control piece. A nozzle passage is formed between a nozzle body and a two-piece outlet check, and a sac cavity is formed by the rate control piece and the nozzle body and fluidly connects a through-hole in the rate control piece to nozzle outlets. A starting-flow clearance is formed by the rate control piece and the timing control piece, and is opened by moving the timing control piece relative to the rate control piece. Moving the rate control piece relative to the nozzle body opens a main-flow seat. The nozzle assembly provides a slow starting injection rate shape in a common rail or similar fuel system and improved controllability over minimum delivery quantities.

A high-pressure fuel supply pump includes a plunger, a valve member, a valve seat, a pressurizing chamber, and a fuel passage. The fuel passage includes a gap passage portion formed in a gap between the valve seat and the valve member. The fuel passage also includes a bent passage portion extending in a bent direction with respect to the gap passage portion, on the downstream side of the gap passage portion. The inner surface of the valve member, on a side thereof that faces the valve seat, has a convex shape in an area of the valve member that is between the bent passage portion and the gap passage portion.

The present invention relates to a fuel pump for pumping fuel, comprising a piston (2) and a diaphragm seal element (3), which seals on an inner annular seal seat (4) and an outer annular seal seat (5), wherein the following equation is satisfied: (Ra.sup.2−ra.sup.2)/(ri+L).sup.2=ra/ri, where ri is the inner radius of the inner seal seat (4), ra is the inner radius of the outer seal seat (5), Ra is the outer diameter of the piston (2) and L is a difference between an outer radius (Ria) of the inner seal seat (4) and the inner radius (ri) of the inner seal seat (4). The invention further relates to a method for operating a fuel pump.

A high-pressure fuel pump for a fuel delivery system of an internal combustion engine includes a pressure limiting valve positioned between an outlet and an inlet of the pump. The valve includes a spring-loaded closing element and a closing body that radially holds the closing element in place, and that has a concave receiving portion configured to at least partially receive the closing element. The receiving portion has a radially outer first area with a first opening angle, and a radially inner second area with a second opening angle larger than the first opening angle. The first area and the second area are located outside of a contact region between the closing element and the closing body.

Provided is a high-pressure fuel pump that ensures oil tightness even at high fuel pressure and has a small and lightweight inexpensive discharge valve structure. Therefore, a high-pressure fuel pump according to the present invention includes: a discharge valve arranged on a discharge side of a pressurizing chamber; a discharge valve seat on which the discharge valve is seated; and a facing member configured independently as a separate member from the discharge valve seat and located on an opposite side of the discharge valve seat with the discharge valve interposed therebetween, in which a stroke direction regulating portion that regulates displacement of the discharge valve in a stroke direction is formed on a tapered surface of the facing member.