Abstract: A pressure booster of a fuel injection system includes a displaceable piston unit (30a, 31a), which on one end can be subjected to pressure via a pressure booster chamber on the low-pressure side and on the other end has a pressure booster chamber on the high-pressure side for fuel compression. The piston unit has a further piston cross section, which is reduced compared to the first piston cross section provided for imposing pressure, for embodying a differential chamber that is connectable to a leak fuel line. At least one control conduit connects the pressure booster chamber on the low-pressure side to the differential chamber, whose opening is closed or opened as a function of the motion of at least parts of the piston unit.

Abstract: A fuel injection system for internal combustion engines includes an injector supplied from a high-pressure fuel source and with a pressure booster device, in which the closing piston can be acted upon by fuel pressure to attain a force exerted on the closing piston in the closing direction, and in which the closing pressure chamber and the return chamber of the pressure booster device are formed by a common closing pressure return chamber, and all the portions of the closing pressure return chamber communicate with one another permanently for exchanging fuel, so that despite a low pressure boost by the pressure booster device, a relatively low injection opening pressure is attainable.

Abstract: A fuel injection apparatus for injecting fuel into the combustion chambers of an internal combustion engine includes a high pressure accumulator, a pressure booster, and a metering valve. The pressure booster includes a working chamber and a control chamber that are separated from each other by an axially movable piston. A pressure change in the control chamber produces a pressure change in a compression chamber that acts on a nozzle chamber via a fuel inlet. The nozzle chamber encampasses a nozzle needle. A nozzle spring chamber that acts on the injection valve element can be filled on the high-pressure side via a line that leads from the compression chamber and contains an inlet throttle restriction. On the outlet side, the nozzle spring chamber is connected to a chamber of the pressure booster via a line that contains an outlet throttle restriction.

Abstract: A fuel injection system for internal combustion engines having a fuel injection valve communicating with a high-pressure source includes a control valve, which has a valve body with a longitudinally displaceably guided control piston. The control piston is guided in a bush, which is surrounded at least partly inside the valve body by an annular chamber, which communicates with the high-pressure source.

Abstract: A device for injecting fuel into the combustion chamber an internal combustion engine including a high-pressure storage chamber, a pressure booster, and a metering valve. The pressure booster includes a work chamber and a control chamber separated from one another by an axially movable piston. A pressure change in the control chamber causes a pressure change in a compression chamber of the pressure booster. The compression chamber acts upon a nozzle chamber in the nozzle body. A pressure relief valve (40) is in a control line between the control chamber of the pressure booster and a 2/2-way metering valve, the pressure relief valve includes a valve body that acts upon at least one hydraulic chamber and can be made to communicate with the pressure prevailing in the high-pressure storage chamber.

Abstract: A fuel injection system for internal combustion engines has at least one stroke-controlled injector. A pressure booster that has a movable piston is connected between the at least one injector and a high-pressure working medium source. The movable piston divides a primary chamber, which can be connected to the high-pressure working medium source, from a pressure chamber that communicates with the at least one injector and is filled with fuel. The pressure booster generates a first fuel system pressure in the injector, which is used for the injection. The fuel injection system has means for furnishing a further, second fuel system pressure, and these means can be used for injection without activating the pressure booster.

Abstract: A fuel injection system has a pressure booster unit (1), disposed between a pressure reservoir chamber and a nozzle chamber, which unit has a displaceable piston unit (4) for boosting the pressure of the fuel to be supplied to the nozzle chamber. For controlling the pressure booster unit (1), the piston unit (4) has a transition from a larger to a smaller piston cross section and a differential chamber (2) formed thereby, which is connected to the pressure reservoir chamber via a filling path (13) having a filling valve (10). A reduction in the control quantity during the triggering of the pressure booster unit (1) and the performance of a rapid restoration of the piston unit (4) are attained.

Abstract: A pressure booster of a fuel injection system includes a displaceable piston unit (30a, 31a), which on one end can be subjected to pressure via a pressure booster chamber on the low-pressure side and on the other end has a pressure booster chamber on the high-pressure side for fuel compression. The piston unit has a further piston cross section, which is reduced compared to the first piston cross section provided for imposing pressure, for embodying a differential chamber that is connectable to a leak fuel line. At least one control conduit connects the pressure booster chamber on the low-pressure side to the differential chamber, whose opening is closed or opened as a function of the motion of at least parts of the piston unit.

Abstract: A fuel injection system for internal combustion engines includes an injector supplied from a high-pressure fuel source and a pressure booster device, in which the pressure booster device has a movable pressure booster piston that disconnects a chamber that is connectable to the high-pressure fuel source from a high-pressure chamber communicating with the fuel injector, and by filling a return chamber of the pressure booster device with fuel and by evacuating the return chamber of fuel, the fuel pressure in the high-pressure chamber can be varied, and the fuel injector has a movable closing piston, for opening and closing injection openings, which protrudes into a closing pressure chamber, so that the closing piston can be subjected to fuel pressure to attain a force acting in the closing direction on the closing piston, and the closing pressure chamber and the chamber are formed by a common work chamber, and all the portions of the work chamber communicate permanently with one another for exchanging fuel.

Abstract: A fuel injector for injecting fuel into a combustion chamber of an internal combustion engine, having a pressure booster in which the piston divides a work chamber, acted upon permanently by fuel via a pressure source, from a pressure-relievable differential pressure chamber. A pressure change in the differential pressure chamber is effected via an actuation of a servo valve. The control chamber of the servo valve can be pressure-relieved via a relief valve and which opens or closes a hydraulic connection of the differential pressure chamber with a return. For closing the servo valve piston, the control chamber can be acted upon by a fuel volume diverted from the differential pressure chamber. The action of fuel on the control chamber is effected via lines that contain throttle restrictions. A pressure relief of the control chamber is effected via a relief valve into a return on the low-pressure side.

Abstract: An injection nozzle of a stroke-controlled fuel injection device has a control chamber for triggering a nozzle needle and also has a nozzle chamber connectable to a pressure booster. The communication between a differential chamber of the pressure booster and a leakage line and the communication between a control chamber and a leakage line are controllable with the aid of a common valve.

Abstract: A fuel injection system includes a pressure chamber. The pressure chamber has a displaceable piston (24), which can be subjected to pressure via a low-pressure-side pressure booster chamber, for compressing the fuel in a high-pressure-side pressure booster chamber to be delivered to an injector. The stroke of the piston (24) is controllable essentially by the pressure in a differential chamber of the pressure chamber and is used to vary the fuel pressure delivered to the injector. Means (24, 25) for enlarging the cross section of the outlet cross section out of the differential chamber of the pressure chamber are provided. The fuel pressure during the injection can be varied. A pressure increase can be achieved with simple means.

Abstract: A fuel injection system has one or more unit fuel injectors or pump-line-nozzle units, corresponding in number to the cylinders, for compressing the fuel. The fuel injection system includes means for generating two different injection pressures during the injection and at least one valve for controlling the injection with a cross sectional control. The fuel injection with the aid of the unit fuel injector or a pump-line-nozzle unit can be achieved over a wide rpm range with great precision.

Abstract: A method for injecting fuel at at least two different high fuel pressures via injectors into the combustion chamber of an internal combustion engine. The fuel injection at the higher fuel pressure takes place by pressure-controlled features, during the fuel injection, at least one lower fuel pressure is generated. To that end, a fuel injection system has one local diversion unit for each injector, and the diversion unit can be activated or deactivated via a valve unit.

Abstract: A fuel injection system for internal combustion engines, having a fuel injector that can be supplied from a high-pressure fuel source and having a pressure booster device is proposed, in which the pressure booster device has a movable pressure booster piston that disconnects a chamber that is connectable to the high-pressure fuel source from a high-pressure chamber communicating with the fuel injector, and by filling a return chamber of the pressure booster device with fuel and by evacuating the return chamber of fuel, the fuel pressure in the high-pressure chamber can be varied, and the fuel injector has a movable closing piston, for opening and closing injection openings, which protrudes into a closing pressure chamber (12; 112), so that the closing piston can be subjected to fuel pressure to attain a force acting in the closing direction on the closing piston, and the closing pressure chamber (12; 112) and the chamber (26; 126) are formed by a common work chamber, and all the portions (12, 47, 26; 112, 130

Abstract: A fuel injection system for internal combustion engines, with a fuel injector that can be supplied from a high-pressure fuel source and with a pressure booster device, is proposed in which the closing piston (13; 113) of the injector protrudes into a closing pressure chamber (12; 112), so that the closing piston can be acted upon by fuel pressure to attain a force exerted on the closing piston in the closing direction, and in which the closing pressure chamber (12; 112) and the return chamber (27; 127) of the pressure booster device are formed by a common closing pressure return chamber (12, 27, 41; 112, 127, 141), and all the portions (12, 27; 112, 127) of the closing pressure return chamber communicate (41; 141) with one another permanently for exchanging fuel, so that despite a low pressure boost by the pressure booster device, a relatively low injection opening pressure is attainable.

Abstract: In a fuel injection system for an internal combustion engine, in which fuel at at least two differently high fuel pressures can be injected via injectors into the combustion chamber of the engine, parallel to a bypass line a hydraulic pressure booster is provided for generating the higher fuel pressure; the pressure booster is actuatable and deactuatable via a valve unit. Since the pressure booster is not constantly in operation, and the losses from friction are also reduced, the efficiency is improved.

Abstract: A fuel injection system includes a pressure booster. The pressure booster has a displaceable piston (24), which can be subjected to pressure via a pressure booster chamber on the low-pressure side, for compressing the fuel, to be delivered to an injector, in a pressure booster chamber on the high-pressure side. The stroke of the piston (24) is controllable essentially by the pressure in a differential chamber of the pressure booster and is used to vary the fuel pressure delivered to the injector. Means (24, 25) for continuously variable definition of the inlet cross section to the pressure booster chamber of the pressure booster on the low-pressure side or of the outlet cross section from the differential chamber of the pressure booster are provided.

Abstract: A fuel injection is effected by means of a high-pressure pump (2) and a pressure reservoir chamber (6) for generating and storing a first system pressure. This system pressure is not used for injection; instead, by means of the pressure booster unit (9), a higher injection pressure is generated during the injection, and this injection pressure can be reduced to shape the course of injection. By means of this invention, an improved capability of metering the fuel injection and an improved execution of fast switching times are achieved.

Abstract: A pressure-controlled fuel injection system (1) has a common pressure reservoir, one injector (3) per cylinder, and one local pressure booster (4) assigned to each injector (3). A 2/2-way valve (14) is provided for metering fuel to the injector (3).