Abstract: A fuel injection system for internal combustion engines with a fuel injector that can be supplied from a high-pressure fuel source has an injection valve, with injection nozzles pointing toward the combustion chamber, and coaxial inner and outer nozzle needles assigned to the injection nozzles are triggerable as a function of pressure to open and close various injection cross sections at the injection nozzles. Each of the nozzle needless is assigned a respective damping piston, and the damping pistons are movable relative to one another and act on a damping chamber which can be made to communicate with a low-pressure return system via an outlet throttle. In addition to the damping chamber, a closing chamber is provided, to which an end face of the outer nozzle needle is exposed in the closing direction.

Abstract: A fuel injection system includes a pressure chamber having a displacable piston 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 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. Provision is made 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 simply achieved.

Abstract: A fuel injection system includes a pressure booster having a displaceable piston which can be subjected to pressure via a pressure booster chamber on the low-pressure side for compressing the fuel in a pressure booster chamber on the high-pressure side to be delivered to an injector. The stroke of the piston is controllable by the pressure in a differential chamber of the pressure booster and is used to vary the fuel pressure delivered to the injector. Means 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 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 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 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 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 apparatus includes a shared pressure reservoir, an injector, a pressure intensifier, and valves for controlling the injection process and the pressure intensification. A modular design is produced by means of a pressure intensifier module, and a valve module, thereby reducing costs and increases flexibility in the manufacture of fuel injection apparatuses.

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: 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).

Abstract: In a pressure-controlled fuel injection system, a nozzle needle is subjected to pressure in the closing direction by a nozzle spring. A nozzle chamber for opening the nozzle needle is connectable to a pressure reservoir via a pressure line. A hydraulic device is embodied to reinforce the closing performance of the nozzle needle. As a result, a faster closing performance of the nozzle needle is achieved.

Abstract: A pressure booster for increasing the injection pressure in direct-injection internal combustion engines with a plurality of cylinders, in particular diesel engines, having a booster piston which has a relatively large end face that is subjected to a relatively low pressure and a relatively small end face at which in the pumping stroke an elevated injection pressure prevails, wherein on the side remote from the relatively large end face, because of the difference in size between the two end faces of the booster piston, an idle volume results. The idle volume is in communication with a cantilevered spring reservoir disposed locally for each individual cylinder or centrally for all the cylinders of the engine.

Abstract: A fuel injection system (1) for internal combustion engines has at least one stroke-controlled injector (10). A pressure booster (9) that has a movable piston (26) is connected between the at least one injector (10) and a high-pressure working medium source (5). The movable piston (26) divides a primary chamber (13), which can be connected to the high-pressure working medium source (5), from a pressure chamber (8) that communicates with the at least one injector (10) and is filled with fuel. The pressure booster (9) generates a first fuel system pressure in the injector (10), which is used for the injection. The fuel injection system (1) has means for furnishing a further, second fuel system pressure, and these means can be used for injection without activating the pressure booster (10).

Abstract: In a fuel injection system for an internal combustion engine, in which the fuel pumped by means of a high-pressure pump can be injected into the combustion chamber of the engine at at least two different, high fuel pressure via injectors, between the high-pressure pump and the injectors, at least one central pressure booster unit for all the injectors is provided. The pressure booster unit is triggerable in a targeted way as need, and as a result the fuel which is at the higher pressure can be better regulated in quantity, and the losses from friction can be reduced accordingly as well.