Showing papers by "Friedrich Boecking published in 1998"

Kraftstoffeinspritzvorrichtung für Brennkraftmaschinen

Abstract: Es wird eine Kraftstoffeinspritzvorrichtung fur Brennkraftmaschinen vorgeschlagen, bei der ein Kraftstoffeinspritzventil (1) durch den Druck in einem Druckraum (9), der auf eine Druckschulter (16) wirkt, in seiner Offnungs- und Schliesbewegung gesteuert wird. Die Druckzufuhr zum Druckraum (9) wird durch ein Steuerventilglied (23) gesteuert, das wiederum durch einen Druck in einem Arbeitsraum (31) bewegt wird. Der Druck im Arbeitsraum (31) wird durch ein Vorsteuerventil (55) gesteuert, das einen Schlieskorper (56) aufweist, der unter Einwirkung eines Piezoantriebs (73) von einem zweiten Ventilsitz (64) zu einem ersten Ventilsitz (60) bewegt wird und dabei eine Entlastungsleitung (50) des Arbeitsraumes (31) kurzzeitig offnet. Das hat ein Offnen des Steuerventilglieds (23) und eine Zufuhr von Kraftstoffhochdruck zum Druckraum (9) zwecks Einspritzung zur Folge. Dabei ergibt sich eine sehr kleine Voreinspritzmenge. Fur die Durchfuhrung einer Haupteinspritzmenge wird der Schlieskorper (56) in eine Mittelstellung zwischen den Ventilsitzen (64, 60) positioniert und somit eine langere Verbindung des Kraftstoffhochdruckzuflusses zum Druckraum (9) hergestellt.

Piezoelectrically actuated fuel injection valve

Abstract: A valve for controlling liquids which for its actuation is provided with a liquid-filled coupling chamber, which is disposed between an actuator piston of a piezoelectric actuator and a piston that actuates a valve member. To compensate for liquid losses suffered by the coupling chamber, which is briefly at high in each work cycle, the pressure difference that exists during the return stroke of the actuator piston between the coupling chamber and the opposite sides of the actuator piston and of the that actuates the valve member that are remote from the coupling chamber is utilized to achieve refilling in valveless fashion along gaps. The valve is used for use in fuel injection systems for internal combustion engines of motor vehicles.

Fuel injector for auto-ignition internal combustion engines

Abstract: The invention relates to a fuel injector for auto-ignition internal combustion engines. Said injector comprises a body (30) with a conical seat surface (32) from which injection openings (34) originate. It also comprises a valve needle which is slidably guided in the entry zone of the blind bore, through a guiding section, against a closing force and against the direction of fuel flow. The valve needle has a closing cone (12) disposed at the end of a valve spindle connected to the guiding section and co-operating with the seat surface (32). The valve spindle (10) circumferentially defines an annular space (40) for fuel feeding. The inventive injector is characterised in that a throttle device with a variable throttle cross section is placed in the transition zone between the valve spindle (10) and the closing cone (20). Said throttle device allows for a varying amount of injected fuel, depending on the axial displacement of the valve needle.

Fluid control valve

Abstract: The valve piston (25) moves in a guide bore (28) with a leak path formed between the surface of the piston and the bore wall The leak path connects a coupling chamber (30) to a low pressure chamber (18) containing a hydraulic pressure medium A filling valve (33) is provided in the connection, located on the piston, which actuates the valve member (22) Preferably a control chamber (41) is provided between coupling chamber and filling valve,

Liquid control valve

Abstract: The valve has a valve member (22) that has an operating piston (34) subjected from a pressure spring (24) in the closing direction of the valve member to the installation on a valve seat (20). The valve member forms a movable wall of a pressure chamber which is restricted from an actuator piston of a piezo-actuator. Movement of the piston results in a pressure increase in the pressure chamber, whereby the operating piston can be adjusted against the force of the pressure spring. The pressure chamber is restricted from two differently sized pressure surfaces, of which one is formed from a thin- walled membrane.

Piezoelectric actuator used e.g. for a fuel injection valve, a hydraulic valve, a micro-pump or an electrical relay

Abstract: A piezoelectric actuator has internal electrodes (7) alternately contacting different ones of two external electrode groups (3-6) on different side faces A piezoelectric actuator has: (a) a stack of piezoelectric plates (2) of polarization direction perpendicular to the plate plane; (b) a control voltage source (11) with two connections (12a, b); (c) two groups of external electrodes (3-6) electrically connected to respective control voltage source connections and applied to different side faces of the stack; and (d) internal electrodes (7) arranged between the plates and alternately contacting different external electrodes Preferred Features: The piezoelectric material is a lead zirconate-titanate (PZT)

Injection valve for a fuel system of a vehicle

Abstract: An injection valve for a fuel injection system, for multistage control of the effective cross section of an injection opening. A spring/stop system with a first compression spring for a control valve for a control chamber, whose pressure determined the position of the valve shaft of an injection valve member. When a valve opens, the spring/stop system allows its valve tappet a first axial stroke, which is limited by a primary stop on an axially movable adapter. The axial mobility of the adapter allows the valve tappet, counter to the compressive force of a first compression spring, an additional, second axial stroke, which is limited by an end stop structurally connected to the housing. The valve tappet is urged in the closing direction of the control valve by a second compression spring braced against the housing of the injection valve, and in the closed state of the control valve the spring force of the second compression spring is less than that of the first compression spring. Applicable to a control valve of a common rail injector.

A fuel injection device for internal combustion engines

Abstract: The fuel injection system includes a HP fuel storage (1) with a pressure sensor (6). A fuel injection valve (9) controlled by a control unit (8) is supplied with fuel, and has an element (14), the opening and closing of which, is determined by a pressure, acting on this valve element in a control chamber (24). The valve element must be relieved, for carrying out an injection of the pressure in the control chamber. A control valve (31) sequentially controls two different discharge cross-sections of a discharge duct (49) of the control chamber, one after the other facilitating a matched opening of the fuel injection valve element, for a first and a main injection of fuel.

Valve including a step-up piston for controlling fluids

Abstract: A valve for controlling liquids for its actuation is provided with a liquid-filled coupling chamber, which is disposed between a step-up piston, actuatable by a piezoelectric actuator, and a piston that actuates a valve member. To compensate for leakage in the coupling chamber that is at high pressure, a filling valve is provided. The filling valve is disposed between the step-up piston and the piezoelectric actuator. Upon each return stroke of the piezoelectric actuator, the step-up piston follows the piezoelectric actuator with a time lag, so that the filling valve opens briefly and allows filling of the coupling chamber. The valves intended for use in fuel injection systems for internal combustion engines of motor vehicles.

Piezoelectric actuated valve with membrane chamber

Abstract: A valve for controlling fluids, which in order to be actuated, cooperates with a fluid-filled membrane actuator. A coupling chamber provided in the membrane actuator is sealed by two membranes as dividing walls. In order to compensate for fluid losses produced by pressure acting on the membrane actuator, a filling valve is provided, which is disposed in the region of one of the two membranes. A refilling of the membrane actuator during the closed phase of the control valve is assured by way of the filling valve. A filling of this kind can also compensate for length changes of the piezoelectric actuator, the valve, or the valve housing. The valve is designated for use in fuel injection devices for internal combustion engines of motor vehicles.

Fuel injection apparatus

Abstract: A fuel injection system for an internal combustion engine has a three-way valve (40) between the high pressure fuel feed (8) and the injection valve. The control valve opens and closes the injection valve by switching between two stable settings. The control valve has a valve element (42) with conical valve seals (46,47) at each end, and with the upper end of the valve element connected by a shaft to a piston (45) and to a servo drive (59) e.g. a solenoid. The relative sizes of the piston, the connecting shaft and the fuel feeds are such that when the valve is lifted, to close the high pressure fuel feed, and to vent the control side of the injection valve to the fuel sump (6), the pressure of the high pressure fuel feed (53) holds the valve in this position until the servo drive pushes the valve back into the open position, where it is also held by the pressure of the fuel.

In line fuel control valve for fuel injector has a two stage opening action with a limited amount of fuel injected prior to the main injection pulse

Abstract: An in line fuel control valve (1) is fitted between the fuel pump and the separate injectors of an IC engine. It operates in a mechanical-hydraulic manner and requires no external servo force. The valve has a limited flow duct (11) to provide a progressively increasing small fuel flow followed by the full valve open setting for the main fuel pulse. Two control springs and two valve elements are fitted in line, with the limited fuel flow duct through the main valve element.