Daimler-benz Ag

Mercedes-benz Aktiengesellschaft

Daimler Chrysler Ag

Dr. Ing. H.c. F. Porsche Aktiengesellschaft

Mercedes-benz Ag and Robert Bosch Gmbh

Ulrich Augustin

Volker Schwarz

Hermann Hiereth

Alois Raab

Klaus Binder

Heinz Rathmayr

Gerhard Fraenkle

Kurt Oberklammer

Peter Reisenbichler

Michael Schittler

Klaus-Juergen Thiele

Ekkehard Koehler

Claus-Juergen Schimmeyer

Bernd Busenthur

Wolfgang Notz

A piezoelectric injector for fuel-injection systems of internal combustion engines has a piezoactuator guided with spring pretensioning in a valve housing. The actuator presses a sealing piece onto its valve seat through an actuating part, with the actuating part consisting of a pressure pin passing through the piezoactuator and having a head part resting on piezoactuator. The pressure pin and piezoactuator are of the same length and are made of the same ceramic material, in operation the sealing piece is lifted off its valve seat by piezoactuator which is expanded when in the charged state.

Piezoelectric injector for fuel-injection systems of internal combustion

An accumulator fuel injection system for a multi-cylinder internal combustion engine with solenoid controlled fuel injection valves each including a spring loaded fuel injection nozzle needle to which fuel under pressure is supplied under the control of a solenoid controlled piston with a valve structure at one end for controlling fuel supply to the nozzle needle, the control piston has at its end an axial projection extending into a fuel supply cavity to restrict the fuel passage from the fuel supply cavity through the valve structure to the nozzle needle upon initial lifting of the control piston but permitting unrestricted flow after a predetermined lifting stroke, that is, solenoid energization period, and the solenoid is energized by a first energization pulse of a duration t.sub.1 and, after an interruption period t.sub.2 by a main energization pulse t.sub.2 during which the control piston is fully lifted for unrestricted fuel flow to the nozzle needle.

Accumulator injection system

In a fuel injector for direct fuel injection into a cylinder of an internal combustion engine under the control of an electromagnetic valve, wherein an injector housing has a control piston and a valve body disposed in a cylindrical opening formed therein whereby the high pressure fuel supply to a nozzle valve at one end of the injector is controlled, the valve body forms a valve whose downstream end is in communication, by way of a throttle structure, with a low pressure fuel return line through whichfuel under pressure can be released, the discharge of fuel from the downstream end of the valve body to the return line being further controlled such that fuel can be discharged to the fuel return line only when the nozzle valve is closed.

Fuel injector with magnetic valve control for a multicylinder internal

In a magnetic valve controlled fuel injector for a storage fuel injection system of a multi-cylinder internal combustion engine wherein the injector includes an upper housing part with a control piston, a lower housing part with a valve piston, a nozzle body with a spring loaded needle valve, and a fuel supply passage extending through the lower housing part to the valve piston and through the valve and control pistons to a control chamber from which fuel can be released under the control of a magnetic valve disposed on top of the upper housing part. The fuel supply passage further extends from the valve piston to a pressure chamber around the nozzle needle which when unseated by opening the magnetic control valve permits ejection of fuel from the pressure chamber. The valve and control piston which are disposed in the lower and respectively, upper housing parts are disposed in engagement with each other in the area of the jointure of the upper and the lower housing parts.

Magnetic valve-controlled injector for a storage fuel injection system

In a magnetic valve controlled fuel injector for a multi-cylinder internal combustion engine with a nozzle needle movably disposed in the injector housing and spring-biased onto a nozzle needle seat wherein high pressure fuel supplied to the nozzle needle through a fuel admission passage lifts the nozzle needle off its seat for discharging fuel therefrom, a control piston with a valve portion is disposed in the injector housing and controlled by an electromagnetic valve for admitting fuel under pressure to the fuel admission passage and a pressure piston is movably disposed in a pressure space formed at one end of a space receiving the nozzle needle spring which, with one end biases the nozzle needle toward its closed position and is supported at its other end by the pressure piston and a throttled communication passage extends between the fuel admission passage and the pressure space for moving the pressure piston toward the nozzle needle when the pressure in the fuel admission passage remains because of a defect in the injector so as to move the nozzle needle onto the nozzle needle seat to interrupt the fuel discharge from the injector.

Magnetic valve controlled fuel injector

In a fuel injection system for a multi-cylinder internal combustion engine with magnetic valve controlled direct injection fuel injectors of which each comprises a housing consisting of several parts, one part having an injection nozzle with a spring loaded nozzle needle and another part including a control piston with a valve structure having an integral valve seat for controlling high pressure fuel admission to a fuel supply passage extending through the housing to the injection nozzle, a control chamber is formed at the other end of the control piston and is in communication with the high pressure fuel supply, and a magnetic valve arranged adjacent the control chamber controls communication of the control chamber with a drain line for releasing pressurized fuel from the control chamber to permit unseating of the control piston so as to establish communication between the pressurized fuel supply and the injection nozzle past a lug extending from the control piston into a fuel admission bore.

Fuel injection system for a multi-cylinder internal combustion engine

In a process for regulating the injection quantities of injectors which are fluidically connected with a common pressure line in a common-rail injection system of an internal-combustion engine, a fuel pump provides fuel in the pressure line under a static nominal pressure. Control signals for opening and closing within individual injection periods for achieving respective identical injection quantities are supplied to the injectors by a regulator unit. In the case of different flow rates of the individual injectors respective identical injection quantities are achieved by the regulator unit by changing the respective injection period on the basis of a measuring signal. For this purpose, a pressure gauge inserted into the pressure line generates a measuring signal from a measurement of the static measuring pressure in the pressure line in each case after the closing of an injector. From the difference between the nominal pressure before the injection and the differential pressure after the injection, the regulator unit determines the fuel quantity taken from the pressure line during the injection. In case of a deviation from a known desired value, the regulator causes a corresponding change of the injection period of the diagnosed injector.

Process for regulating the injection quantities of injectors of a

A control for an injection system of a multicylinder internal combustion engine has a high pressure pump connected to a distributor element provided with outlet openings from which branch lines lead separately to groups of injection valves. The distributor element has first and second spring biased pistons that are operable to block selectively fuel to the branch lines, each of the pistons having a throttle point situated therein. When a major leak develops downstream from the distributor element, the branch line in which the leak has occurred is automatically shut off by the associated piston in the distributor element, due to the imbalance in pressure which results. When a minor leak develops, one of the branch lines is automatically closed by a control unit shutting off the injection valves associated with the other branch line, while the high pressure pump continues to deliver for at least one operating cycle. The other branch line and associate injection valves operate once again, with an adjustment of the fuel volume supplied when elimination of the leak is detected. When, however, it is determined that the leak still exists, injection valves that have been shut off are activated once again without delivering new fuel, and one branch line and associated injection valves continues to operate while adjusting the amount of fuel delivered.

Control of an injection system for a multicylinder internal combustion

In a fuel injection system for a multi-cylinder internal combustion engine with magnetic valve controlled direct injection fuel injectors of which each includes a housing having an injection nozzle with a nozzle needle biased into a closed position by a spring disposed in a spring chamber, and a magnetic valve controlled control piston having a valve structure at one end for controlling high pressure fuel admission to a fuel supply passage leading to the needle nozzle, the spring chamber is in communication with the fuel supply passage by a communication passage including a throttle structure permitting limited fuel flow to the spring chamber such that, upon failure of the injector resulting in a continuous pressurization of the fuel supply passage, the pressure in the spring chamber builds up to seat the nozzle needle thereby interrupting fuel ejection from the injector.

Fuel injection system for a multicylinder internal combustion engine

In a fuel injector for a fuel injection system of an internal combustion engine including an injector housing with an injection nozzle controlled by a valve needle extending through a cylindrical fuel pressure space from which fuel under pressure is supplied to the fuel injection nozzle, the fuel pressure space includes a flow limiting piston with a seating surface at its end adjacent the needle tip and the injector housing has a valve seat disposed opposite the piston seating surface for blocking fuel flow to the injector nozzle when the flow limiting piston is seated on the valve seat and the flow limiting piston is spring-biased away from the valve seat with a force which is sufficient to normally hold the flow limiting piston away from the valve seat, but which permits closing of the valve when the fuel flow to the injector nozzle becomes excessive.

Fuel injector

In a fuel injection control system for a multi-cylinder internal combustion engine including a high pressure fuel pump for supplying fuel under pressure to the fuel injection valves of the various cylinders through a distribution line including a fuel distribution element dividing the fuel supply to two groups of fuel injection valves, the fuel distribution element includes a piston disposed in a cylinder and adapted to interrupt fuel flow to any one of the two groups in which a leak occurs such that fuel supply to the other group of fuel injection valves can be maintained for an emergency operation of the engine. If small leaks are detected by the electronic engine operating control, the valves of one of the groups are momentarily deactivated to cause the distribution element to interrupt the fuel supply to the other group of fuel injection valves. If this action eliminates the leakage, the leakage is determined to be in the supply to the other group of fuel injection valves and the fuel supply to the other group of fuel injection valves remains interrupted while the fuel injection valves of the one group are reactivated to permit operation of the engine on an emergency basis.

Fuel injection control system for a multi-cylinder internal combustion

An injector with solenoid-valve control provided for diesel internal-combustion engines has a lateral fuel delivery conduit into a pressure accumulator reaching, on one hand, as far as the needle seat of a nozzle needle and on the other hand as far as a piston arranged on the rear side of the nozzle needle. A control space in the injector is connected by a controllable solenoid valve to the pressure accumulator or, for pressure relief, to a low-pressure conduit. A fuel filter is arranged in the pressure accumulator in the mouth region of the fuel delivery conduit.

Injector with solenoid-valve control for fuel injection into diesel

In a method of controlling the operation of an internal combustion engine with fuel injection by way of a common high pressure (common rail) fuel supply line to which high pressure fuel is supplied by a high pressure fuel pump and from which fuel is admitted to the various cylinders of the internal combustion engine by valve controlled fuel injection nozzles, the fuel pressure in the common fuel supply line between the end of an injection and the start of a fuel supply period is monitored at distinct timely spaced measurement points and, if a pressure difference between the measurement points is sensed in excess of a predetermined limit value indicating an injector malfunction, the high pressure fuel supply to the common fuel supply line is interrupted by deactivating the high pressure fuel pump while fuel injection through the operative nozzles is maintained so as to rapidly reduce the pressure in the common fuel supply line.

Method of controlling an internal combustion engine upon detection of a

In a method of recognizing operating errors in the fuel injection system of an internal combustion engine wherein fuel is supplied by a fuel pump via a common fuel supply line to a number of fuel injectors, the fuel pressure in the common fuel supply line is determined at least at two predetermined points in time between which the pressure should not change when the system is properly operating and an operating error is indicated if a difference in pressure is determined which exceeds a predetermined threshold value.

Method of recognizing operating errors in a fuel injection system of an

In a method of injection fuel for Diesel engine comprising a high pressure injection pump with a fuel supply line for supplying high pressure fuel to fuel injection nozzles wherein a fuel control line extends between the pump and a low pressure fuel supply line for discharge in excess fuel thereto under the control of a magnetic valve which is closed to end the discharge of excess fuel and initiate pumping of fuel, the magnetic valve is opened at the end of fuel pumping at a point corresponding to a piston stroke length h after the upper dead center of the piston such that, when communication between the pump and the low pressure fuel line is established, pressure pulses in the low pressure fuel line are avoided.

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Kernen, Germany

Ulrich Augustin