Abstract: A fuel injector for the injection of fuel into the combustion chamber of an internal combustion engine includes a valve needle guided in a nozzle body, the valve needle being actuable by an actuator and acted upon by a restoring spring in such a manner that a valve-closure member which is in operative connection to the valve needle is retained in sealing contact against a valve-seat surface. Formed at a downstream-side end of the fuel injector is a projection which projects beyond the valve-closure member of the fuel injector.

Abstract: A fuel injector for fuel-injection systems of internal combustion engines having a piezoelectric or magnetostrictive actuator, includes a hydraulic coupler which actuates a valve-closure member (3) formed on a valve needle. The valve-closure member cooperates with a valve-seat surface to form a valve-sealing seat. The coupler includes a master piston and a slave piston which are guided in bores of a guide sleeve. Located between the master piston and the slave piston is a pressure chamber filled with a hydraulic fluid. A corrugated tube is positioned around the guide sleeve which is sealingly joined to the master piston at one end and to the slave piston at the other end, and which seals a supply chamber for the hydraulic fluid from a surrounding fuel chamber.

Abstract: A fuel injector, in particular a fuel injector for fuel-injection systems of internal combustion engines, includes a first magnetic coil cooperating with a first armature, a second magnetic coil cooperating with a second armature, and a valve needle which is in force-locking connection with the first armature via a first flange and to the second armature via a second flange, to actuate a valve-closure member. A restoring spring acts upon the valve needle in a closing direction of the fuel injector. A first positioning spring, situated between the first flange and the first armature, acts upon the first armature in the closing direction of the fuel injector, while a second positioning spring, situated between the second flange and the second armature, acts upon the second armature in an opening direction of the fuel injector.

Abstract: A fuel injector, in particular a fuel injector for fuel-injection systems of internal combustion engines, has a piezoelectric or magnetostrictive actuator which actuates, via a hydraulic coupler a valve-closure member formed on a valve needle, the valve-closure member cooperating with a valve-seat surface to form a sealing seat. The coupler is made up of a pressure cylinder, a pressure-cylinder support joined to the pressure cylinder, and a pressure piston guided in this pressure cylinder, which form a pressure chamber; and of a coupler spring element between the pressure piston and the pressure cylinder which generates a prestressing force that forces the pressure piston out of the pressure cylinder.

Abstract: A fuel injector for fuel-injection systems of internal combustion engines having a piezoelectric or magnetostrictive actuator, includes a hydraulic coupler which actuates a valve-closure member (3) formed on a valve needle. The valve-closure member cooperates with a valve-seat surface to form a valve-sealing seat. The coupler includes a master piston and a slave piston which are guided in bores of a guide sleeve. Located between the master piston and the slave piston is a pressure chamber filled with a hydraulic fluid. A corrugated tube is positioned around the guide sleeve which is sealingly joined to the master piston at one end and to the slave piston at the other end, and which seals a supply chamber for the hydraulic fluid from a surrounding fuel chamber.

Abstract: A fuel injector (1) for the injection of fuel into the combustion chamber of an internal combustion engine includes a valve needle (4) guided in a nozzle body (3), the valve needle (4) being actuable by an actuator (7) and acted upon by a restoring spring (9) in such a manner that a valve-closure member (5) which is in operative connection to the valve needle (4) is retained in sealing contact against a valve-seat surface (6). Formed at a downstream-side end (13) of the fuel injector (1) is a projection (14) which projects beyond the valve-closure member (5) of the fuel injector (1).

Abstract: A fuel injector (1), in particular a fuel injector (1) for fuel-injection systems of internal combustion engines, comprises a first magnetic coil (2) cooperating with a first armature (3), a second magnetic coil (4) cooperating with a second armature (5), and a valve needle (14) which is in force-locking connection with the first armature (3) via a first flange (12) and to the second armature (5) via a second flange (13), to actuate a valve-closure member. A restoring spring (17) acts upon the valve needle (14) in a closing direction of the fuel injector (1). A first positioning spring (15), situated between the first flange (12) and the first armature (3), acts upon the first armature (3) in the closing direction of the fuel injector (1), while a second positioning spring (16), situated between the second flange (13) and the second armature (5), acts upon the second armature (5) in an opening direction of the fuel injector (1).

Abstract: A fuel injector (1), in particular a fuel injector for fuel-injection systems of internal combustion engines has a piezoelectric or magnetostrictive actuator (14) which actuates, via a hydraulic coupler (35a) a valve-closure member (3) formed on a valve needle (2), the valve-closure member (3) cooperating with a valve-seat surface (5) to a sealing seat (6). The coupler (35a) is made up of a pressure cylinder (34), a pressure-cylinder support (35) joined to the pressure cylinder (34), and a pressure piston (33) guided in this pressure cylinder (35), which form a pressure chamber (37); and of a coupler spring element (38) between the pressure piston (33) and the pressure cylinder (34) which generates a prestressing force that forces the pressure piston (33) out of the pressure cylinder (34).

Abstract: The valve has a seat valve with a hollow cone-shaped valve seat (28) and a closing member in the form of a segment of a ball. The valve seat is centrally fed by an influx bore that communicates with a pressure fluid inlet. A tappet that has the closing member is engaged by a magnet armature that acts on the seat valve in the closing direction and by a restoring spring that acts on it in the opening direction. The valve, which is embodied as an on-off valve, can be controlled in stable intermediary positions because of the following measures: the sealing diameter of the valve seat has at least 1.3 times the diameter of the influx bore; the cone angle of the valve seat is at most 110.degree.

Abstract: The valve has a seat valve with a hollow conical valve seat and a closing member in the form of a ball segment. The valve seat is centrally fed by an influx bore that communicates with a pressure fluid inlet. A tappet that has the closing member is engaged by a magnet armature that acts on the seat valve in the closing direction and a restoring spring that acts in the opening direction. The valve, which is embodied as an on-off valve, can be controlled into stable intermediary positions because of the following measures: The diameter of the influx bore virtually corresponds to the seal diameter of the valve seat; the cone angle of the valve seat is at most 90.degree.

Abstract: An apparatus and a method for driving a solenoid valve, which includes a coil and a movable armature. To move the armature, current and/or voltage is applied to the coil in a clocked manner. By varying the driving, the solenoid valve can be operated optionally as a control valve or as a relief valve.

Abstract: An electromatically operated valve for automatic setting of a reduced flow cross section effective for a closed position of the valve is to be achieved. The valve has, in a valve dome, a longitudinally movable magnet armature with a separate valve push-rod which carries a closing element of a first seat valve which is open in the rest position. The first seat valve is located in a valve chamber from which a first pressure medium passage leads to a control chamber remote from the closing element and a second pressure medium passage leads to a control chamber, near the closing element, of the magnet armature. In addition, a second valve formed from the magnet armature and the valve push-rod is provided by means of which a connection between the first pressure medium passage and the second control chamber can be switched on and off.

Abstract: An electromagnetic valve having a magnet armature which can be moved longitudinally in a valve dome and the valve tappet of which carries a closing member of a first seat valve, which valve is open in the rest position. The first seat valve is situated in a valve chamber, from which first and second pressure-medium passages lead to first and second chambers arranged axially at both ends of the magnet armature. The connection between the first control chamber, which is remote from the closing member, and the second chamber, which is close to the closing member, is controlled by the magnet armature by a second seat valve, which is open in the rest position. When the second seat valve assumes its closed position, the pressure in the first control chamber, which is remote from the closing member, brings about a displacement of the magnet armature counter to the force of a return spring, resulting in a reduction in the cross section of flow of the first seat valve.

Abstract: An electromagnetic valve having a magnet armature which can be moved longitudinally in a valve dome includes a valve tappet which carries a closing member of a first seat valve, which is open in the rest position. The first seat valve is situated in a valve chamber, from which first and second pressure-medium passages lead to ends of the magnet armature, which is sealed off at the circumference. The connection between the first pressure-medium passage and a control chamber between that end of the magnet armature which is remote from the closing member and the valve dome is controlled by a second seat valve (54), which is closed in the rest position. When the second seat valve (54) assumes its open position, the pressure in the control chamber (46), which is remote from the closing member, brings about a displacement of the magnet armature counter to the force of a return spring, resulting in a reduction in the cross section of flow of the first seat valve.