EP1135591A1 - Valve for controlling fluids - Google Patents
Valve for controlling fluidsInfo
- Publication number
- EP1135591A1 EP1135591A1 EP00972589A EP00972589A EP1135591A1 EP 1135591 A1 EP1135591 A1 EP 1135591A1 EP 00972589 A EP00972589 A EP 00972589A EP 00972589 A EP00972589 A EP 00972589A EP 1135591 A1 EP1135591 A1 EP 1135591A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- valve
- pressure chamber
- leakage
- chamber
- system pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M63/00—Other fuel-injection apparatus having pertinent characteristics not provided for in groups F02M39/00 - F02M57/00 or F02M67/00; Details, component parts, or accessories of fuel-injection apparatus, not provided for in, or of interest apart from, the apparatus of groups F02M39/00 - F02M61/00 or F02M67/00; Combination of fuel pump with other devices, e.g. lubricating oil pump
- F02M63/0012—Valves
- F02M63/0014—Valves characterised by the valve actuating means
- F02M63/0015—Valves characterised by the valve actuating means electrical, e.g. using solenoid
- F02M63/0026—Valves characterised by the valve actuating means electrical, e.g. using solenoid using piezoelectric or magnetostrictive actuators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
- F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
- F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M47/00—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure
- F02M47/02—Fuel-injection apparatus operated cyclically with fuel-injection valves actuated by fluid pressure of accumulator-injector type, i.e. having fuel pressure of accumulator tending to open, and fuel pressure in other chamber tending to close, injection valves and having means for periodically releasing that closing pressure
- F02M47/027—Electrically actuated valves draining the chamber to release the closing pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M61/00—Fuel-injectors not provided for in groups F02M39/00 - F02M57/00 or F02M67/00
- F02M61/16—Details not provided for in, or of interest apart from, the apparatus of groups F02M61/02 - F02M61/14
- F02M61/167—Means for compensating clearance or thermal expansion
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
- F02M2200/30—Fuel-injection apparatus having mechanical parts, the movement of which is damped
- F02M2200/304—Fuel-injection apparatus having mechanical parts, the movement of which is damped using hydraulic means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
- F02M2200/70—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger
- F02M2200/703—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic
- F02M2200/705—Linkage between actuator and actuated element, e.g. between piezoelectric actuator and needle valve or pump plunger hydraulic with means for filling or emptying hydraulic chamber, e.g. for compensating clearance or thermal expansion
Definitions
- the invention is based on a valve for controlling fluids according to the type defined in more detail in patent claim 1.
- DE 197 328 02 discloses a fuel injection device for internal combustion engines with a high-pressure fuel source.
- the fuel injector has two valve seats with sealing surfaces on a closing body
- Actuation by means of a piezo drive interact in a movement sequence, the closing body initially being in the closed position on the first valve seat, then being brought into an intermediate position between the valve seats in order to then return to the second valve seat in a closed position.
- Pressure level determines an opening or closing position of a valve needle in the force-balanced designed fuel injection device and thus the fuel injection is controlled.
- the fuel injection is made possible while the closing body is in an intermediate position between the two valve seats. In this way, fuel injection is implemented by means of a single excitation of the piezo drive.
- the loss times in the control of the known fuel injection device are advantageously relatively short.
- the invention has for its object to provide a valve for controlling liquids, with which the aforementioned disadvantages, in particular overshoots in the central position of the valve closing member, are avoided.
- valve according to the invention for controlling liquids with the features of claim 1 has the advantage that the actuating movements of the valve member are damped by means of steaming elements in such a way that the valve closing member is stabilized in its central position between the two valve seats.
- high-frequency injections of liquids, in particular fuel can also be carried out exactly by the valve according to the invention, without there being any fluctuations in the injection quantity due to overshoots of the valve closing element in an unfavorable intermediate position.
- valve according to the invention hydraulic forces are generated by the damping organs, which act briefly against the direction of movement of the valve closing member and thus brake it accordingly into a central position between the two valve seats. Accordingly, the valve closing member can reach its stable middle position without the occurrence of overshoots.
- a significant advantage of the invention is further that the hydraulic counter forces generated by the damping elements only act for a short time, so that the piezoelectric unit does not move the valve closing member against these damping forces m the closed position to the second valve seat.
- the piezoelectric unit can thus be dimensioned correspondingly small, as a result of which the production costs are reduced.
- Figure 1 is a schematic, partial representation of a first embodiment of the invention in a fuel injection valve for internal combustion engines in longitudinal section
- Figure 2 is a schematic, partial illustration of a second embodiment in a fuel injection valve in longitudinal section with a hollow drilled leakage pin
- FIG. 3 shows a diagram with diagrams for a leakage pin, a gap pressure and a gap width being plotted over a length of the pin.
- the first exemplary embodiment shown in FIG. 1 shows the use of the valve according to the invention in a fuel injection valve 1 for internal combustion engines of motor vehicles.
- the fuel injection valve 1 is designed here as a common rail injector, the fuel injection being controlled via the pressure level in a valve control chamber 12, which is connected to a high pressure supply.
- a valve member 2 is controlled via a piezoelectric unit designed as a piezoelectric actuator 3, which is arranged on the side of the valve member 2 facing away from the valve control chamber and combustion chamber.
- the piezoelectric actuator 3 is made up of several layers and has an actuator head 4 on its side facing the valve member 2 and an actuator foot 5 on its side facing away from the valve member, which is supported on a wall 26.
- An actuator piston 7 of the valve member 2 is in contact with the actuator head 4 via a support 6, the piston being of stepped diameter.
- the valve member 2 is axially displaceable in a bore 8 of a valve body 9 designed as an elongated bore and, in addition to the actuating piston 7, also comprises an actuating piston 10 actuating a valve closing member 13, the actuating piston 7 and the actuating piston 10 having different diameters.
- the actuating piston 7 and the actuating piston 10 are coupled to one another by means of a hydraulic transmission.
- the hydraulic transmission is designed as a hydraulic chamber 11, which transmits the deflection of the piezoelectric actuator 3.
- the hydraulic chamber 11 encloses a common compensation volume between the two pistons 7 and 10 delimiting it, of which the actuating piston 10 is designed with a smaller diameter and the actuating piston 7 with a larger diameter.
- the hydraulic chamber 11 is clamped between the actuating piston 7 and the actuating piston 10 in such a way that the actuating piston 10 of the valve member 2 makes a stroke which is increased by the ratio of the piston diameter when the larger actuating piston 7 is moved by the piezoelectric actuator 3 by a certain distance.
- the valve member 2 the
- the actuating piston 7, the actuating piston 10 and the piezoelectric actuator 3 lie one behind the other on a common axis.
- the filling of the hydraulic chamber 11 is not shown in FIG. 1. Tolerances based on temperature gradients in the component or different coefficients of thermal expansion of the materials used and any setting effects can be compensated for via the compensation volume of the hydraulic chamber 11, without a change in the position of the valve closing element 13 to be controlled thereby occurring.
- valve closing member 13 At the valve control chamber end of the valve member 2, the spherical valve closing member 13 is provided.
- the valve closing member 13 cooperates with valve seats 14, 15 formed on the valve body 9, the lower valve seat 15 being assigned a spring 27 which holds the valve closing member 13 on the upper valve seat 14 when the valve control chamber 12 is relieved.
- valve seats 14, 15 are formed in a valve low-pressure chamber 16 formed by the valve body 9, which is connected to a leakage drain channel 17 and to a compensation channel 19 leading to a valve system pressure chamber 18.
- the leakage drain channel 17 has a damping element designed as a throttle 20.
- the valve low-pressure chamber 16 has a connection, formed by the lower valve seat 15, to the valve control chamber 12, which is only indicated in FIG. 1, and a filling channel 21 which flows into the equalization channel 19.
- a movable valve control piston which is not shown in the drawing, is arranged in the valve control chamber 12.
- An injection nozzle of the fuel injection valve 1 is controlled in a manner known per se by axial movements of the valve control piston in the valve control chamber 12.
- An injection line, which supplies the injection nozzle with fuel, usually also flows into the valve control chamber 12.
- the injection line is one for multiple fuel injectors common high-pressure storage space (common rail) connected.
- the high-pressure storage space is fed in a known manner from a high-pressure fuel pump with high-pressure fuel from a storage tank.
- the compensation channel 19 leading to the valve system pressure chamber 18 has a spring-loaded pressure relief valve 22 regulating the system pressure in the valve system pressure chamber 18 on the valve low pressure chamber side and is equipped with a damping element designed as a throttle 24.
- the filling channel 21 is connected to the compensation channel 19 via a leakage pin 23 regulating the filling, which is fitted into a bore and enables a predetermined leakage.
- the leakage pin 23 enables the realization of a small flow cross-section in a simple manner, however, of course, a precision bore can of course also serve as a filling device.
- the material of the leakage pin 23 has a greater coefficient of thermal expansion than the material of the
- Valve body 9 has that, with increasing temperature, a viscosity-related increase in the volume flow flowing around the leakage pin 23 is severely limited, an almost constant volume flow with temperature changes being achievable with an optimal choice of material.
- the valve system pressure chamber 18 connects to the piezo-side end of the bore 8 and is delimited on the one hand by the valve body 9 and on the other hand by a sealing element 25 connected to the actuating piston 7 of the valve member 2 and the valve body 9.
- the sealing element is designed as a bellows-like membrane 25 and prevents the piezoelectric actuator 3 from coming into contact with the fuel contained in the valve system pressure chamber 18.
- the sealing element can be used in others Versions can also be designed as a corrugated tube or the like.
- the fuel injection valve 1 according to FIG. 1 operates in the manner described below.
- Fuel can get into the valve low pressure chamber 16 from the valve control chamber 12 connected to the high pressure storage chamber and can then escape through the leakage drain channel 17.
- Diameter of the actuating piston 7 projecting into the hydraulic chamber 11 increases proportionally, the biasing force of the piezoelectric actuator 3 can be adjusted via the diameter of the actuating piston 7, with the largest possible piston diameter being advantageous. Values adapted to the individual case can be selected by the person skilled in the art.
- Valve body 9 occurs, the control piston 7 penetrates into the compensating volume of the hydraulic chamber 11 with an increase in temperature or withdraws from it when the temperature drops without this having any effect on the closed and open position of the valve member 2 and the fuel valve 1 as a whole.
- the piezoelectric actuator 3 If an injection is to take place through the fuel injection valve 1, the piezoelectric actuator 3 is energized, as a result of which its axial expansion increases abruptly. With such a rapid actuation of the piezoelectric actuator 3, it is supported on the wall 26, as a result of which the actuating piston 10 with the valve closing member 7 of the valve member 2 moves from its upper valve seat 14 into a central position between the two valve seats 14, 15. Due to the actuating movement of the valve member 2, the volume of the valve system pressure chamber 18 is reduced due to the moving membrane 25, as a result of which the system pressure in the valve system pressure chamber 18 increases accordingly. This pressure increase cannot be reduced immediately by the pressure relief valve 22, since the
- Throttle 24 briefly builds up the system pressure. As a result, a hydraulic counterforce acts on the diaphragm 25 against the actuating movement of the valve member 2. The actuating movement is accordingly damped, so that the valve closing member 13 is stabilized in the central position between the two valve seats 14, 15.
- valve closing member 13 can be moved into its closed position on the lower valve seat 15, as a result of which fuel can no longer penetrate from the valve control chamber 12 into the valve low pressure chamber 16. The fuel injection is then ended.
- FIG. 2 a second exemplary embodiment of fuel injector 1 is shown, in which:
- the fuel injection valve 1 shown here differs in that the throttle 24 arranged in the compensating channel 19 is replaced by a leakage pin 23, which is at least partially drilled hollow, for filling the valve system pressure chamber.
- the leakage pin 23 has a throttle area a and a leakage area b.
- the bore in which the leakage pin 23 ⁇ is arranged has an annular groove 28 which is connected to the pressure relief valve 22.
- the throttle 24 in the first exemplary embodiment is replaced here by a gap throttling, so that the mode of operation of the damping element of the fuel injector does not change.
- the throttle 20 arranged in the leakage discharge channel 17 was also dispensed with in the second exemplary embodiment.
- the leakage pin 23 ⁇ has a substantially greater coefficient of thermal expansion than the material of the valve body 9 in order to limit a viscosity-related increase in the temperature as the temperature increases.
- the damping elements designed as throttles 20, 24 or leakage pin 23 can alternatively or also be used side by side in the valve according to the invention. The operation of the valve can be further stabilized if several steaming elements are used side by side.
- FIG. 3 shows a diagram with diagrams, in which on the one hand a gap width s (x) and a gap pressure p (x) over the gap height or pin length x of the leakage pin 23 "can be seen.
- the pressure decrease takes place in the gap between the leakage pin 23 ⁇ and the surrounding bore linear if the bore and the leakage pin 23 ⁇ fitted into the bore are cylindrical, the maximum pressure corresponds to an internal pressure p_0 in the leakage pin 23 ⁇ and there is a minimum pressure in the gap at a maximum gap width s_0 ,
- the internal pressure p_0 in the hollow leakage pin 23 ⁇ is constant over the pin length x.
- the hydraulic medium for filling the hydraulic chamber 11 is the fuel, which is also injected into a combustion chamber of an internal combustion engine. With a suitable separation between the fuel supply and the discharge of the exiting in the hydraulic chamber 11 Hydraulic medium and a tracking of leakage losses, it is also possible to use separate 01 such as Motorol as the hydraulic medium.
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Fuel-Injection Apparatus (AREA)
- Electrically Driven Valve-Operating Means (AREA)
- Details Of Valves (AREA)
Abstract
The invention relates to a valve (1) for controlling a fluid, comprising a piezoelectric unit (3) for actuating an axially displaceable valve member (2) which can be positioned in the bore (8) of a valve body (9).One end of the bore (8) borders on a valve system pressure chamber (18) which is limited by a sealing element (25). The other end of said bore (8) borders on a valve low pressure chamber (16) having a run-off channel (17) for spillage. Said channel (17) is connected via a compensating channel (19) including a pressure limiting element (20, 23`) and a filling device (23, 23`) and comprising a valve system pressure chamber (18), to a valve low pressure chamber (16). A valve closing member (13) is connected to a valve member (2) which cooperates with at least two valve seats (14, 15), located in the valve low pressure chamber (16) and designed for opening and closing the valve (1), in such a way that said valve low pressure chamber (16) is separated from a high pressure valve control room (12). In an intermediate position between the valve seat (14, 15), said member fluidically connects the valve low pressure chamber (16) to the valve control chamber (12), whereby at least one damping element (20, 23`, 24) which generates a temporary opposing hydraulic force is provided in order to dampen the controlling movements of the valve member (2).
Description
Ventil zum Steuern von FlüssigkeitenValve for controlling liquids
Stand der TechnikState of the art
Die Erfindung geht von einem Ventil zum Steuern von Flussigkei- ten gemäß der in Patentanspruch 1 naher definierten Art aus.The invention is based on a valve for controlling fluids according to the type defined in more detail in patent claim 1.
Aus der DE 197 328 02 ist eine Kraftstoffeinspritzvorrichtung für Brennkraftmaschinen mit einer Kraftstoffhochdruckquelle bekannt. Die Kraftstoffeinspritzvorrichtung besitzt zwei Ventilsitze, die mit Dichtflachen eines Schließkorpers beiDE 197 328 02 discloses a fuel injection device for internal combustion engines with a high-pressure fuel source. The fuel injector has two valve seats with sealing surfaces on a closing body
Betätigung durch einen Piezoantrieb in einer Bewegungsabfolge zusammenwirken, wobei sich der Schließkorper anfanglich in Schließstellung an dem ersten Ventilsitz befindet, dann in eine Zwischenstellung zwischen die Ventilsitze gebracht wird, um anschließend wieder in eine Schließstellung an den zweiten Ventilsitz zu gelangen.Actuation by means of a piezo drive interact in a movement sequence, the closing body initially being in the closed position on the first valve seat, then being brought into an intermediate position between the valve seats in order to then return to the second valve seat in a closed position.
Auf diese Weise wird durch den Bewegungsablauf des Schließkorpers vom einen zum anderen Ventilsitz eine kurzzeitige Entlastung eines Ventilsteuerraumes erreicht, über dessenIn this way, a short-term relief of a valve control chamber is achieved through the movement sequence of the closing body from one valve seat to the other
Druckniveau eine Offnungs- bzw. Schließstellung einer Ventilnadel in der kraftausgeglichen ausgebildeten Kraftstoffeinspritzvorrichtung bestimmt und somit die Kraftstoffeinspritzung gesteuert wird. Die Kraftstoffeinspritzung
wird dabei ermöglicht, wahrend sich der Schließkorper in einer Zwischenstellung zwischen den beiden Ventilsitzen befindet. Auf diese Weise wird die Kraftstoffeinspritzung mittels einer einzigen Erregung des Piezoantriebes realisiert.Pressure level determines an opening or closing position of a valve needle in the force-balanced designed fuel injection device and thus the fuel injection is controlled. The fuel injection is made possible while the closing body is in an intermediate position between the two valve seats. In this way, fuel injection is implemented by means of a single excitation of the piezo drive.
Da eine zeitraubende Bewegungsumkehr des Schließkorpers wahrend der Kraftstoffeinspritzung nicht erforderlich ist, sind die Verlustzeiten bei der Ansteuerung der bekannten Kraftstoffeinspritzvorrichtung vorteilhafterweise relativ gering.Since a time-consuming reversal of the movement of the closing body during the fuel injection is not necessary, the loss times in the control of the known fuel injection device are advantageously relatively short.
Jedoch hat sich gezeigt, daß Uberschwingungen des Schließkorpers auftreten, wenn dieser in eine Mittelstellung zwischen den beiden Ventilsitzen gebracht werden soll. Sobald der Schließkorper zu weit in Richtung des ersten oder des zweiten Ventilsitzes schwingt, kann dies in nachteiliger Weise zu Ungenauigkeiten bei der Dosierung der Einspritzmenge fuhren.However, it has been shown that overshoots of the closing body occur when it is to be brought into a central position between the two valve seats. As soon as the closing body swings too far in the direction of the first or the second valve seat, this can disadvantageously lead to inaccuracies in the metering of the injection quantity.
Es ist möglich, die Mittelstellung des Schließkorpers zwischen den Ventilsitzen mittels Federkraft zu stabilisieren, jedoch hat dies den Nachteil, daß der Piezoantrieb entgegen der Federkraft in seine Schließstellung an dem zweiten Ventilsitz bewegt werden mußte. Demzufolge mußte der Piezoantrieb entsprechend groß dimensioniert werden, wodurch die Fertigungskosten und die konstruktiven Abmessungen der Einspritzvorrichtung negativ beeinflußt werden.It is possible to stabilize the central position of the closing body between the valve seats by means of spring force, but this has the disadvantage that the piezo drive had to be moved into its closed position on the second valve seat against the spring force. As a result, the piezo drive had to be dimensioned correspondingly large, as a result of which the manufacturing costs and the structural dimensions of the injection device are negatively influenced.
Der Erfindung liegt die Aufgabe zugrunde, ein Ventil zur Steuerung von Flüssigkeiten zu schaffen, mit dem die vorbezeichneten Nachteile, insbesondere Uberschwingungen in der Mittel- Stellung des Ventilschließglieds, vermieden werden.
Vorteile der ErfindungThe invention has for its object to provide a valve for controlling liquids, with which the aforementioned disadvantages, in particular overshoots in the central position of the valve closing member, are avoided. Advantages of the invention
Das erfindungsgemaße Ventil zur Steuerung von Flüssigkeiten mit den Merkmalen des Patentanspruchs 1 hat den Vorteil, daß die Stellbewegungen des Ventilgliedes derart mittels Dampfungsorga- nen gedampft werden, daß das Ventilschließglied in seiner Mittelstellung zwischen den beiden Ventilsitzen stabilisiert wird. Demzufolge können auch hochfrequente Einspritzungen von Flüssigkeiten, insbesondere von Kraftstoff, durch das erfin- dungsgemaße Ventil exakt vorgenommen werden, ohne daß es dabei zu Schwankungen bei der Einspritzmenge durch Uberschwingungen des Ventilschließgliedes in eine ungunstige Zwischenstellung kommt .The valve according to the invention for controlling liquids with the features of claim 1 has the advantage that the actuating movements of the valve member are damped by means of steaming elements in such a way that the valve closing member is stabilized in its central position between the two valve seats. As a result, high-frequency injections of liquids, in particular fuel, can also be carried out exactly by the valve according to the invention, without there being any fluctuations in the injection quantity due to overshoots of the valve closing element in an unfavorable intermediate position.
Bei dem erfindungsgemaßen Ventil werden durch die Dampfungsorga- ne hydraulische Kräfte erzeugt, die kurzzeitig gegen die Bewegungsrichtung des Ventilschließgliedes wirken und dieses somit entsprechend in eine Mittelstellung zwischen den beiden Ventilsitzen abbremsen. Demnach kann das Ventilschließglied seine stabile Mittelstellung ohne das Auftreten von Uberschwingungen erreichen.In the valve according to the invention, hydraulic forces are generated by the damping organs, which act briefly against the direction of movement of the valve closing member and thus brake it accordingly into a central position between the two valve seats. Accordingly, the valve closing member can reach its stable middle position without the occurrence of overshoots.
Ein bedeutender Vorteil der Erfindung besteht des weiteren darin, daß die von den Dampfungsorganen erzeugten hydraulischen Gegenkräften nur kurzzeitig wirken, so daß die piezoelektrische Einheit das Ventilschließglied nicht gegen diese Dampfungskrafte m die Schließstellung zum zweiten Ventilsitz bewegt. Somit kann die piezoelektrische Einheit entsprechend gering dimensioniert werden, wodurch die Fertigungskosten reduziert werden.A significant advantage of the invention is further that the hydraulic counter forces generated by the damping elements only act for a short time, so that the piezoelectric unit does not move the valve closing member against these damping forces m the closed position to the second valve seat. The piezoelectric unit can thus be dimensioned correspondingly small, as a result of which the production costs are reduced.
Weitere Vorteile und vorteilhafte Ausgestaltungen des Gegenstandes der Erfindung sind der Beschreibung, der Zeichnung und den Patentansprüchen entnehmbar.
ZeichnungFurther advantages and advantageous configurations of the subject matter of the invention can be gathered from the description, the drawing and the patent claims. drawing
Zwei Ausfuhrungsbeispiele des erfindungsgemaßen Ventils zur Steuerung von Flüssigkeiten sind in der Zeichnung dargestellt und werden in der folgenden Beschreibung naher erläutert. Es zeigenTwo exemplary embodiments of the valve according to the invention for controlling liquids are shown in the drawing and are explained in more detail in the following description. Show it
Figur 1 eine schematische, ausschnittsweise Darstellung eines erstes Ausfuhrungsbeispiels der Erfindung bei einem Kraftstoffeinspritzventil für Brennkraftmaschinen im Längsschnitt, Figur 2 eine schematische, ausschnittsweise Darstellung eines zweiten Ausfuhrungsbeispiels bei einem Kraftstoffeinspritzventil im Längsschnitt mit einem hohlgebohrten Leckagestift, undFigure 1 is a schematic, partial representation of a first embodiment of the invention in a fuel injection valve for internal combustion engines in longitudinal section, Figure 2 is a schematic, partial illustration of a second embodiment in a fuel injection valve in longitudinal section with a hollow drilled leakage pin, and
Figur 3 ein Schaubild mit Diagrammen zu einem Leckagestift, wobei ein Spaltdruck und eine Spaltbreite über eine Stiftlange aufgetragen sind.FIG. 3 shows a diagram with diagrams for a leakage pin, a gap pressure and a gap width being plotted over a length of the pin.
Beschreibung der AusfuhrungsbeispieleDescription of the exemplary embodiments
Das in der Figur 1 dargestellte erste Ausfuhrungsbeispiel zeigt eine Verwendung des erfindungsgemaßen Ventils bei einem Kraftstoffeinspritzventil 1 für Brennkraftmaschinen von Kraftfahrzeugen. Das Kraftstoffeinspritzventil 1 ist vorliegend als ein Common-Rail-Injektor ausgebildet, wobei die Kraftstoffeinspritzung über das Druckniveau in einem Ventilsteuerraum 12, welcher mit einer Hochdruckversorgung verbunden ist, gesteuert wird.The first exemplary embodiment shown in FIG. 1 shows the use of the valve according to the invention in a fuel injection valve 1 for internal combustion engines of motor vehicles. The fuel injection valve 1 is designed here as a common rail injector, the fuel injection being controlled via the pressure level in a valve control chamber 12, which is connected to a high pressure supply.
Zur Einstellung eines Einspritzbeginns, einer Einspritzdauer und einer Einspritzmenge über Kräfteverhältnisse in dem Kraftstoffe- inspritzventil 1 wird ein Ventilglied 2 über einen als piezoelektrischen Aktor 3 ausgebildeten piezoelektrischen Einheit angesteuert, welcher auf der ventilsteuerraum- und brennraumab- gewandten Seite des Ventilgliedes 2 angeordnet ist.
Der piezoelektrische Aktor 3 ist aus mehreren Schichten aufgebaut und weist auf seiner dem Ventilglied 2 zugewandten Seite einen Aktorkopf 4 sowie auf seiner dem Ventilglied abgewandten Seite einen Aktorfuß 5 auf, der sich an einer Wand 26 abstutzt. An dem Aktorkopf 4 liegt über ein Auflager 6 ein Stellkolben 7 des Ventilgliedes 2 an, welcher in seinem Durchmesser gestuft ausgeführt ist.In order to set an injection start, an injection duration and an injection quantity via the force relationships in the fuel injection valve 1, a valve member 2 is controlled via a piezoelectric unit designed as a piezoelectric actuator 3, which is arranged on the side of the valve member 2 facing away from the valve control chamber and combustion chamber. The piezoelectric actuator 3 is made up of several layers and has an actuator head 4 on its side facing the valve member 2 and an actuator foot 5 on its side facing away from the valve member, which is supported on a wall 26. An actuator piston 7 of the valve member 2 is in contact with the actuator head 4 via a support 6, the piston being of stepped diameter.
Das Ventilglied 2 ist axial verschiebbar in einer als Langsboh- rung ausgeführten Bohrung 8 eines Ventilkorpers 9 angeordnet und umfaßt neben dem Stellkolben 7 noch einen ein Ventilschließglied 13 betätigenden Betatigungskolben 10, wobei der Stellkolben 7 und der Betatigungskolben 10 unterschiedliche Durchmesser aufweisen. Der Stellkolben 7 und der Betatigungskolben 10 sind mittels einer hydraulischen Übersetzung miteinander gekoppelt.The valve member 2 is axially displaceable in a bore 8 of a valve body 9 designed as an elongated bore and, in addition to the actuating piston 7, also comprises an actuating piston 10 actuating a valve closing member 13, the actuating piston 7 and the actuating piston 10 having different diameters. The actuating piston 7 and the actuating piston 10 are coupled to one another by means of a hydraulic transmission.
Die hydraulische Übersetzung ist als Hydraulikkammer 11 ausgebildet, die die Auslenkung des piezoelektrischen Aktors 3 übertragt. Die Hydraulikkammer 11 schließt zwischen den beiden sie begrenzenden Kolben 7 und 10, von denen der Betatigungskolben 10 mit einem kleineren Durchmesser und der Stellkolben 7 mit einem größeren Durchmesser ausgebildet ist, ein gemeinsames Ausgleichsvolumen ein.The hydraulic transmission is designed as a hydraulic chamber 11, which transmits the deflection of the piezoelectric actuator 3. The hydraulic chamber 11 encloses a common compensation volume between the two pistons 7 and 10 delimiting it, of which the actuating piston 10 is designed with a smaller diameter and the actuating piston 7 with a larger diameter.
Die Hydraulikkammer 11 ist derart zwischen dem Stellkolben 7 und dem Betatigungskolben 10 eingespannt, daß der Betatigungskolben 10 des Ventilgliedes 2 einen um das Übersetzungsverhältnis des Kolbendurchmessers vergrößerten Hub macht, wenn der größere Stellkolben 7 durch den piezoelektrischen Aktor 3 um eine bestimmte Wegstrecke bewegt wird. Das Ventilglied 2, derThe hydraulic chamber 11 is clamped between the actuating piston 7 and the actuating piston 10 in such a way that the actuating piston 10 of the valve member 2 makes a stroke which is increased by the ratio of the piston diameter when the larger actuating piston 7 is moved by the piezoelectric actuator 3 by a certain distance. The valve member 2, the
Stellkolben 7, der Betatigungskolben 10 und der piezoelektrische Aktor 3 liegen dabei auf einer gemeinsamen Achse hintereinander. Die Befullung der Hydraulikkammer 11 ist in Figur 1 nicht weiter dargestellt .
Über das Ausgleichsvolumen der Hydraulikkammer 11 können Toleranzen aufgrund von Temperaturgradienten im Bauteil oder unterschiedlichen Temperaturausdehnungskoeffizienten der verwendeten Materialien sowie eventuelle Setzeffekte ausgeglichen werden, ohne daß dadurch eine Änderung der Position des anzusteuernden Ventilschließgliedes 13 auftritt.The actuating piston 7, the actuating piston 10 and the piezoelectric actuator 3 lie one behind the other on a common axis. The filling of the hydraulic chamber 11 is not shown in FIG. 1. Tolerances based on temperature gradients in the component or different coefficients of thermal expansion of the materials used and any setting effects can be compensated for via the compensation volume of the hydraulic chamber 11, without a change in the position of the valve closing element 13 to be controlled thereby occurring.
An dem ventilsteuerraumseitigen Ende des Ventilgliedes 2 ist das kugelartige Ventilschließglied 13 vorgesehen. Das Ventilschließglied 13 wirkt mit an dem Ventilkorper 9 ausgebildeten Ventilsitzen 14, 15 zusammen, wobei dem unteren Ventilsitz 15 eine Feder 27 zugeordnet ist, die das Ventilschließglied 13 bei Entlastung des Ventilsteuerraums 12 am oberen Ventilsitz 14 halt.At the valve control chamber end of the valve member 2, the spherical valve closing member 13 is provided. The valve closing member 13 cooperates with valve seats 14, 15 formed on the valve body 9, the lower valve seat 15 being assigned a spring 27 which holds the valve closing member 13 on the upper valve seat 14 when the valve control chamber 12 is relieved.
Die Ventilsitze 14, 15 sind in einem vom Ventilkorper 9 gebildeten Ventilniederdruckraum 16 ausgebildet, der mit einem Leckageablaufkanal 17 und mit einem zu einem Ventilsystemdruck- räum 18 fuhrenden Ausgleichkanal 19 verbunden ist. Der Leckageablaufkanal 17 weist ein als Drossel 20 ausgebildetes Dampfungsorgan auf. Darüber hinaus weist der Ventilniederdruckraum 16 eine durch den unteren Ventilsitz 15 gebildete Verbindung zu dem in Figur 1 lediglich angedeuteten Ventilsteuerraum 12 und einen in den Ausgleichkanal 19 mundenden Befullkanal 21 auf.The valve seats 14, 15 are formed in a valve low-pressure chamber 16 formed by the valve body 9, which is connected to a leakage drain channel 17 and to a compensation channel 19 leading to a valve system pressure chamber 18. The leakage drain channel 17 has a damping element designed as a throttle 20. In addition, the valve low-pressure chamber 16 has a connection, formed by the lower valve seat 15, to the valve control chamber 12, which is only indicated in FIG. 1, and a filling channel 21 which flows into the equalization channel 19.
In dem Ventilsteuerraum 12 ist ein bewegbarer Ventilsteuerkolben angeordnet, der in der Zeichnung nicht weiter dargestellt ist. Durch axiale Bewegungen des Ventilsteuerkolbens in dem Ventil- steuerraum 12 wird eine Einspritzdüse des Kraftstoffeinspritzventils 1 auf an sich bekannte Weise gesteuert. In den Ventilsteuerraum 12 mundet üblicherweise auch eine Einspritzleitung, welche die Einspritzdüse mit Kraftstoff versorgt. Die Einspritzleitung ist mit einem für mehrere Kraftstoffeinspritzventile
gemeinsamen Hochdruckspeicherraum (Common-Rail) verbunden. Der Hochdruckspeicherraum wird dabei in bekannter Weise von einer Kraftstoffhochdruckforderpumpe mit Kraftstoff hohen Druckes aus einem Vorratstank gespeist.A movable valve control piston, which is not shown in the drawing, is arranged in the valve control chamber 12. An injection nozzle of the fuel injection valve 1 is controlled in a manner known per se by axial movements of the valve control piston in the valve control chamber 12. An injection line, which supplies the injection nozzle with fuel, usually also flows into the valve control chamber 12. The injection line is one for multiple fuel injectors common high-pressure storage space (common rail) connected. The high-pressure storage space is fed in a known manner from a high-pressure fuel pump with high-pressure fuel from a storage tank.
Der zum Ventilsystemdruckraum 18 fuhrende Ausgleichkanal 19 weist ventilniedruckraumseitig ein den Systemdruck in dem Ventilsystemdruckraum 18 regulierendes, federbelastetes Überdruckventil 22 auf und ist mit einem als Drossel 24 ausgebildeten Dampfungsorgan ausgerüstet. Der Befullkanal 21 ist mit dem Ausgleichkanal 19 über ein die Befullung regulierenden Leckagestift 23 verbunden, der in eine Bohrung eingepaßt ist und eine vorbestimmte Leckage ermöglicht. Der Leckagestift 23 ermöglicht auf einfache Weise die Realisierung eines geringen Stromungsquerschnittes, jedoch kann abweichend selbstverständlich auch eine Prazisionsbohrung als Befulleinrichtung dienen.The compensation channel 19 leading to the valve system pressure chamber 18 has a spring-loaded pressure relief valve 22 regulating the system pressure in the valve system pressure chamber 18 on the valve low pressure chamber side and is equipped with a damping element designed as a throttle 24. The filling channel 21 is connected to the compensation channel 19 via a leakage pin 23 regulating the filling, which is fitted into a bore and enables a predetermined leakage. The leakage pin 23 enables the realization of a small flow cross-section in a simple manner, however, of course, a precision bore can of course also serve as a filling device.
In einer sehr vorteilhaften Ausfuhrung kann auch vorgesehen sein, daß das Material des Leckagestiftes 23 einen derart größeren Wärmeausdehnungskoeffizienten als das Material desIn a very advantageous embodiment, it can also be provided that the material of the leakage pin 23 has a greater coefficient of thermal expansion than the material of the
Ventilkorpers 9 aufweist, daß bei zunehmender Temperatur eine viskositatsbedingte Zunahme des den Leckagestift 23 umströmenden Volumenstroms stark begrenzt wird, wobei mit optimaler Materialwahl eine nahezu konstanter Volumenstrom bei Temperaturanderun- gen erzielbar ist.Valve body 9 has that, with increasing temperature, a viscosity-related increase in the volume flow flowing around the leakage pin 23 is severely limited, an almost constant volume flow with temperature changes being achievable with an optimal choice of material.
Der Ventilsystemdruckraum 18 schließt an das piezoseitige Ende der Bohrung 8 an und ist einerseits durch den Ventilkorper 9 und andererseits durch ein mit dem Stellkolben 7 des Ventilgliedes 2 und dem Ventilkorper 9 verbundenes Dichtelement 25 begrenzt. Das Dichtelement ist als faltenbalgartige Membran 25 ausgebildet und verhindert, daß der piezoelektrischen Aktor 3 mit dem in dem Ventilsystemdruckraum 18 enthaltenen Kraftstoff in Kontakt kommt. Selbstverständlich kann das Dichtelement in anderen
Ausfuhrungen auch als Wellrohr oder dergleichen ausgebildet sein.The valve system pressure chamber 18 connects to the piezo-side end of the bore 8 and is delimited on the one hand by the valve body 9 and on the other hand by a sealing element 25 connected to the actuating piston 7 of the valve member 2 and the valve body 9. The sealing element is designed as a bellows-like membrane 25 and prevents the piezoelectric actuator 3 from coming into contact with the fuel contained in the valve system pressure chamber 18. Of course, the sealing element can be used in others Versions can also be designed as a corrugated tube or the like.
Das Kraftstoffeinspritzventil 1 nach Figur 1 arbeitet dabei in nachfolgend beschriebener Weise.The fuel injection valve 1 according to FIG. 1 operates in the manner described below.
In geschlossenem Zustand des Kraftstoffemspritzventils 1, d.h. bei unbestromtem piezoelektrischen Aktor 3 wird das Ventilschließglied 13 des Ventilglieds 2 in Anlage an dem ihm zugeordneten oberen Ventilsitz 14 gehalten, so daß keinWhen the fuel injection valve 1 is closed, i.e. when the piezoelectric actuator 3 is not energized, the valve closing member 13 of the valve member 2 is held in contact with the upper valve seat 14 assigned to it, so that none
Kraftstoff aus dem mit dem Hochdruckspeicherraum verbundenen Ventilsteuerraum 12 in den Ventilniederdruckraum 16 gelangen und dann durch den Leckageablaufkanal 17 entweichen kann.Fuel can get into the valve low pressure chamber 16 from the valve control chamber 12 connected to the high pressure storage chamber and can then escape through the leakage drain channel 17.
Da sich die Federrate der hydraulischen Feder mit zunehmendemAs the spring rate of the hydraulic spring increases with increasing
Durchmesser des in die Hydraulikkammer 11 ragenden Stellkolbens 7 proportional erhöht, kann die Vorspannkraft des piezoelektrischen Aktors 3 über den Durchmesser des Stellkolbens 7 eingestellt werden, wobei ein möglichst großer Kolbendurchmesser vorteilhaft ist. Es können vom Fachmann an den Einzelfall angepaßte Werte gewählt werden.Diameter of the actuating piston 7 projecting into the hydraulic chamber 11 increases proportionally, the biasing force of the piezoelectric actuator 3 can be adjusted via the diameter of the actuating piston 7, with the largest possible piston diameter being advantageous. Values adapted to the individual case can be selected by the person skilled in the art.
Im Falle einer langsamen Betätigung, wie sie bei einer temperaturbedingten Langenanderung des piezoelektrischen Aktors 3 oder weiterer Ventilbauteile wie z.B. des Ventilglieds 2 oder desIn the case of slow actuation, as occurs when the length of the piezoelectric actuator 3 or other valve components such as e.g. of the valve member 2 or
Ventilkorper 9 auftritt, dringt der Stellkolben 7 mit Temperaturerhöhung in das Ausgleichsvolumen der Hydraulikkammer 11 ein oder zieht sich bei Temperaturabsenkung daraus zurück, ohne daß dies Auswirkungen auf die Schließ- und Offnungsstellung des Ventilgliedes 2 und des Kraftstoffventils 1 insgesamt hat.Valve body 9 occurs, the control piston 7 penetrates into the compensating volume of the hydraulic chamber 11 with an increase in temperature or withdraws from it when the temperature drops without this having any effect on the closed and open position of the valve member 2 and the fuel valve 1 as a whole.
Wenn eine Einspritzung durch das Kraftstoffemspritzventil 1 erfolgen soll, wird der piezoelektrische Aktor 3 bestromt, wodurch dieser seine axiale Ausdehnung schlagartig vergrößert.
Bei einer derartigen schnellen Betätigung des piezoelektrischen Aktors 3 stutzt sich dieser an der Wand 26 ab, wodurch sich der Betatigungskolben 10 mit dem Ventilschließglied 7 des Ventilgliedes 2 von seinem oberen Ventilsitz 14 in eine Mittelstellung zwischen den beiden Ventilsitzen 14, 15 bewegt. Durch die Stellbewegung des Ventilgliedes 2 wird aufgrund der sich bewegenden Membran 25 das Volumen des Ventilsystemdruckraumes 18 verringert, wodurch sich der Systemdruck in dem Ventilsystemdruckraum 18 entsprechend erhöht. Diese Druckerhohung kann nicht sofort durch das Überdruckventil 22 abgebaut werden, da dieIf an injection is to take place through the fuel injection valve 1, the piezoelectric actuator 3 is energized, as a result of which its axial expansion increases abruptly. With such a rapid actuation of the piezoelectric actuator 3, it is supported on the wall 26, as a result of which the actuating piston 10 with the valve closing member 7 of the valve member 2 moves from its upper valve seat 14 into a central position between the two valve seats 14, 15. Due to the actuating movement of the valve member 2, the volume of the valve system pressure chamber 18 is reduced due to the moving membrane 25, as a result of which the system pressure in the valve system pressure chamber 18 increases accordingly. This pressure increase cannot be reduced immediately by the pressure relief valve 22, since the
Drossel 24 den Systemdruck kurzzeitig aufstaut. Dadurch wirkt eine hydraulische Gegenkraft auf die Membran 25 gegen die Stellbewegung des Ventilgliedes 2. Somit wird die Stellbewegung entsprechend gedampft, so daß das Ventilschließglied 13 in der Mittelstellung zwischen den beiden Ventilsitzen 14, 15 stabilisiert wird.Throttle 24 briefly builds up the system pressure. As a result, a hydraulic counterforce acts on the diaphragm 25 against the actuating movement of the valve member 2. The actuating movement is accordingly damped, so that the valve closing member 13 is stabilized in the central position between the two valve seats 14, 15.
Nach Abbau des Systemdruckes durch das Überdruckventil 22 kann das Ventilschließglied 13 in seine Schließstellung an den unteren Ventilsitz 15 bewegt werden, wodurch kein Kraftstoff mehr aus dem Ventilsteuerraum 12 in den Ventilniederdruckraum 16 eindringen kann. Die Kraftstoffeinspritzung ist dann beendet.After the system pressure has been reduced by the pressure relief valve 22, the valve closing member 13 can be moved into its closed position on the lower valve seat 15, as a result of which fuel can no longer penetrate from the valve control chamber 12 into the valve low pressure chamber 16. The fuel injection is then ended.
Danach wird die Bestromung des piezoelektrischen Aktors 3 unterbrochen, wodurch das Ventilglied wieder in die Mittelstellung zwischen die beiden Ventilsitze 14, 15 gebracht wird und eine Kraftstoffeinspritzung erfolgt. Durch den unteren Ventilsitz kann Kraftstoff in den Ventilniederruckraum 16 eindringen. Durch die in dem Leckageablaufkanal 17 angeordnete Drossel 20 kann der Druck nicht sofort abgebaut werden. Die kurzzeitige Druckerhohung in dem Ventilniederdruckraum 16 bewirkt eine hydraulische Gegenkraft, welche die Stellbewegung des Ventilgliedes 2 derart abbremst, daß das Ventilschließglied 13 in seiner Mittelstellung zwischen den beiden Ventilsitzen 14, 15
stabilisiert wird und wieder Kraftstoffeinspritzung realisiert wird. Nach dem Druckabbau in dem Ventilniederdruckraum 16 durch den Leckageablauf anal 17 bewegt sich das Ventilschließglied 13 in seine Schließstellung zum oberen Ventilsitz 14. Somit wird durch jede Ansteuerung (Bestromen oder Beenden des Bestromens) der piezoelektrischen Einheit eine Kraftstoffeinspritzung ermöglicht .Thereafter, the current supply to the piezoelectric actuator 3 is interrupted, as a result of which the valve member is brought back into the middle position between the two valve seats 14, 15 and fuel injection takes place. Fuel can penetrate into the valve low-pressure chamber 16 through the lower valve seat. Due to the throttle 20 arranged in the leakage discharge channel 17, the pressure cannot be reduced immediately. The brief pressure increase in the valve low pressure chamber 16 causes a hydraulic counterforce which brakes the actuating movement of the valve member 2 in such a way that the valve closing member 13 in its central position between the two valve seats 14, 15 is stabilized and fuel injection is realized again. After the pressure in the valve low-pressure chamber 16 has been reduced by the leakage drain anal 17, the valve closing member 13 moves into its closed position to the upper valve seat 14. Thus, each activation (energizing or stopping the energizing) of the piezoelectric unit enables fuel injection.
Bezug nehmend auf Figur 2 ist ein zweites Ausfuhrungsbeispiel des Kraftstoffeinspritzventils 1 dargestellt, bei der ausReferring to FIG. 2, a second exemplary embodiment of fuel injector 1 is shown, in which:
Gründen der Übersichtlichkeit funktionsgleiche Bauteile mit den Figur 1 verwendeten Bezugszeichen bezeichnet sind.For the sake of clarity, functionally identical components are designated with the reference numerals used in FIG. 1.
Gegenüber der Ausfuhrung nach Figur 1 unterscheidet sich das hier gezeigte Kraftstoffeinspritzventil 1 darin, daß die in dem Ausgleichkanal 19 angeordnete Drossel 24 durch einen zumindest abschnittsweise hohlgebohrten Leckagestift 23 zur Befullung des Ventilsystemdruckraumes ersetzt ist. Der Leckagestift 23 weist einen Drosselbereich a und einen Leckagebereich b auf. Die Bohrung, in dem der Leckagestift 23 λ angeordnet ist, weist eine Ringnut 28 auf, die mit dem Überdruckventil 22 verbunden ist. Die Drossel 24 bei dem ersten Ausfuhrungsbeispiel wird hier durch eine Spaltdrosselung ersetzt, so daß sich die Wirkungsweise des Dampfungsorgans des Kraftstoffeinspritzventils nicht verändert. Selbstverständlich sind auch andere konstruktiveCompared to the embodiment according to FIG. 1, the fuel injection valve 1 shown here differs in that the throttle 24 arranged in the compensating channel 19 is replaced by a leakage pin 23, which is at least partially drilled hollow, for filling the valve system pressure chamber. The leakage pin 23 has a throttle area a and a leakage area b. The bore in which the leakage pin 23 λ is arranged has an annular groove 28 which is connected to the pressure relief valve 22. The throttle 24 in the first exemplary embodiment is replaced here by a gap throttling, so that the mode of operation of the damping element of the fuel injector does not change. Of course, other are constructive
Ausgestaltungen des Leckagestifts 23 λ möglich. Darüber hinaus wurde bei dem zweiten Ausfuhrungsbeispiel auch auf die in dem Leckageablaufkanal 17 angeordnete Drossel 20 verzichtet.Embodiments of the leakage pin 23 λ possible. In addition, the throttle 20 arranged in the leakage discharge channel 17 was also dispensed with in the second exemplary embodiment.
Bezuglich der Materialwahl für den Leckagestift 23 Λ kann auch hier vorgesehen sein, daß dieser einen wesentlich größeren Wärmeausdehnungskoeffizienten als das Material des Ventilkorpers 9 aufweist, um bei zunehmender Temperatur eine viskositatsbe- dingte Zunahme des zu begrenzen.
Selbstverständlich können die als Drosseln 20, 24 bzw. Leckagestift 23 ausgebildeten Dampfungsorgane alternativ oder auch nebeneinander bei dem erfindungsgemaßen Ventil verwendet werden. Bei der Verwendung von mehreren Dampfungsorganen nebeneinander kann die Arbeitsweise des Ventils weiter stabilisiert werden.With regard to the choice of material for the leakage pin 23 Λ, it can also be provided here that it has a substantially greater coefficient of thermal expansion than the material of the valve body 9 in order to limit a viscosity-related increase in the temperature as the temperature increases. Of course, the damping elements designed as throttles 20, 24 or leakage pin 23 can alternatively or also be used side by side in the valve according to the invention. The operation of the valve can be further stabilized if several steaming elements are used side by side.
In Figur 3 ist ein Schaubild mit Diagrammen ersichtlich, bei denen einerseits eine Spaltweite s (x) und ein Spaltdruck p(x) über die Spalthohe bzw. Stiftlange x des Leckagestifts 23" ersichtlich sind. Die Druckabnahme erfolgt in dem Spalt zwischen dem Leckagestift 23 Λ und der ihn umgebenden Bohrung linear, wenn die Bohrung und der in die Bohrung eingepaßte Leckagestift 23 Λ zylindrisch ausgebildet sind, wobei der maximale Druck einem Innendruck p_0 in dem Leckagestift 23 λ entspricht und eine minimaler Druck in dem Spalt bei einer maximalen Spaltweite s_0 vorliegt .3 shows a diagram with diagrams, in which on the one hand a gap width s (x) and a gap pressure p (x) over the gap height or pin length x of the leakage pin 23 "can be seen. The pressure decrease takes place in the gap between the leakage pin 23 Λ and the surrounding bore linear if the bore and the leakage pin 23 Λ fitted into the bore are cylindrical, the maximum pressure corresponds to an internal pressure p_0 in the leakage pin 23 λ and there is a minimum pressure in the gap at a maximum gap width s_0 ,
Wie dem mittleren Diagramm zu entnehmen ist, ist der Innendruck p_0 in dem hohlgebohrten Leckagestift 23 Λ über die Stiftlange x konstant .As can be seen from the middle diagram, the internal pressure p_0 in the hollow leakage pin 23 Λ is constant over the pin length x.
Beides zusammen fuhrt dazu, daß die Wandung des hohlgebohrten Leckagestifts 23 λ aufgeweitet wird und die Leckage geringer wird bzw. langsamer ansteigt. Dabei ist sichergestellt, daß bei relativ niedrigen Common-Rail-Drucken eine ausreichende Befullung des Ventilsystemdruckbereichs gewahrleistet ist, wahrend die Leckage bei hohen Common-Rail-Drucken begrenzt wird.Both together leads to the fact that the wall of the hollow drilled leakage pin 23 λ is widened and the leakage becomes smaller or increases more slowly. This ensures that adequate filling of the valve system pressure range is ensured at relatively low common rail pressures, while the leakage at high common rail pressures is limited.
In beiden beschriebenen Ausfuhrungen ist das Hydraulikmedium zur Befullung der Hydraulikkammer 11 der Kraftstoff, welcher auch in einen Brennraum einer Brennkraftmaschine eingespritzt wird. Bei einer geeigneten Trennung zwischen der Kraftstoffzufuhrung und der Abfuhrung des in der Hydraulikkammer 11 austretenden
Hydraulikmediums sowie einer Nachfuhrung von Leckageverlusten ist es auch möglich, separates 01 wie z.B. Motorol als Hydraulikmedium einzusetzen.
In both embodiments described, the hydraulic medium for filling the hydraulic chamber 11 is the fuel, which is also injected into a combustion chamber of an internal combustion engine. With a suitable separation between the fuel supply and the discharge of the exiting in the hydraulic chamber 11 Hydraulic medium and a tracking of leakage losses, it is also possible to use separate 01 such as Motorol as the hydraulic medium.
Claims
1. Ventil zum Steuern von Flüssigkeiten, mit einer piezoelektrischen Einheit (3) zur Betätigung eines in einer Bohrung (8) eines Ventilkorpers (9) axial verschiebbaren Ventilglieds (2), welches eine als Toleranzausgleichselement zum Ausgleich von1. Valve for controlling liquids, with a piezoelectric unit (3) for actuating a valve member (2) which is axially displaceable in a bore (8) of a valve body (9) and which is used as a tolerance compensation element for compensating
Langungstoleranzen der piezoelektrischen Einheit (3) ausgebildete hydraulische Übersetzung (11) aufweist, wobei an ein Ende der Bohrung (8) ein durch ein Dichtelement (25) begrenzter Ventilsystemdruckraum (18) und an ihr anderes Ende ein einen Leckageab- laufkanal (17) aufweisender Ventilniederdruckraum (16) grenzt, welcher über einen Ausgleichkanals (19) , der ein Druckbegrenzungsorgan (20, 23 ~) und eine Befulleinrichtung (23, 23 ' ) aufweist, mit dem Ventilsystemdruckraum (18) verbunden ist, wobei dem Ventilglied (2) ein Ventilschließglied (13) zugeordnet ist, welches mit wenigstens zwei in dem VentilniederdruckraumElongation tolerances of the piezoelectric unit (3) formed hydraulic ratio (11), wherein at one end of the bore (8) a valve system pressure chamber (18) delimited by a sealing element (25) and at its other end a leakage drain channel (17) Valve low pressure chamber (16), which is connected to the valve system pressure chamber (18) via a compensating channel (19), which has a pressure limiting member (20, 23 ~) and a filling device (23, 23 '), the valve member (2) Valve closing member (13) is assigned, which with at least two in the valve low pressure chamber
(16) angeordneten Ventilsitzen (14, 15) zum Offnen und Schließen des Ventils (1) derart zusammenwirkt, daß es in einer Schließstellung den Ventilniederdruckraum (16) von einem unter Hochdruck stehenden Ventilsteuerraum (12) trennt und in einer Zwischenstellung zwischen den Ventilsitzen (14, 15) den Ventilniederdruckraum (16) mit dem Ventilsteuerraum (12) stromungsmaßig verbindet, wobei wenigstens ein kurzfristig hydraulische Gegenkräfte erzeugendes Dampfungsorgan (20, 23 * , 24) zum Dampfen der Stellbewegungen des Ventilgliedes (2) vorgesehen ist.(16) arranged valve seats (14, 15) for opening and closing the valve (1) cooperate in such a way that in a closed position it separates the valve low pressure chamber (16) from a high pressure valve control chamber (12) and in an intermediate position between the valve seats ( 14, 15) connects the valve low pressure chamber (16) with the valve control chamber (12) in terms of flow, at least one damping element (20, 23 * , which briefly generates hydraulic counterforces), 24) is provided for steaming the actuating movements of the valve member (2).
2. Ventil nach Anspruch 1, dadurch gekennzeichnet, daß wenig- stens ein erstes Dampfungsorgan (23', 24) in dem Ausgleichkanal (19) angeordnet ist.2. Valve according to claim 1, characterized in that at least one first damping element (23 ' , 24) is arranged in the compensation channel (19).
3. Ventil nach Anspruch 1 oder 2, dadurch gekennzeichnet, daß wenigstens ein zweites Dampfungsorgan (20) in dem Leckageablauf- kanal (17) angeordnet ist.3. Valve according to claim 1 or 2, characterized in that at least a second damping element (20) is arranged in the leakage drain channel (17).
4. Ventil nach einem der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß das Dampfungsorgan eine Drossel (20, 24) ist.4. Valve according to one of claims 1 to 3, characterized in that the damping element is a throttle (20, 24).
5. Ventil nach einem der Ansprüche 2 bis 4 dadurch gekennzeichnet, daß das erste Dampfungsorgan ein Leckagestift (23 ) mit einem Drosselbereich (a) und einem Leckagebereich (b) zum Befullen des Ventilsystemdruckraumes (18) ist.5. Valve according to one of claims 2 to 4, characterized in that the first damping element is a leakage pin (23) with a throttle area (a) and a leakage area (b) for filling the valve system pressure chamber (18).
6. Ventil nach Anspruch 5, dadurch gekennzeichnet, daß der Leckagestift (23Λ) abschnittsweise hohlgebohrt ist.6. Valve according to claim 5, characterized in that the leakage pin (23 Λ ) is partially drilled.
7. Ventil nach einem der Ansprüche 1 bis 6, dadurch gekennzeichnet, daß das Druckbegrenzungsorgan ein federbelastetes Uber- druckventil (22) zum Einstellen des Systemdruckes in dem Ventilsystemdruckraum (18) ist.7. Valve according to one of claims 1 to 6, characterized in that the pressure limiting member is a spring-loaded pressure relief valve (22) for adjusting the system pressure in the valve system pressure chamber (18).
8. Ventil nach einem der Ansprüche 1 bis 7, dadurch gekennzeichnet, daß die Befulleinrichtung mit einem Leckagestift (23, 23λ) ausgebildet ist, mittels dem der Ventilsteuerraum (12) stro- mungsmaßig mit dem Ventilsystemdruckraum (18) verbindbar ist.8. Valve according to one of claims 1 to 7, characterized in that the filling device is formed with a leakage pin (23, 23 λ ) by means of which the valve control chamber (12) can be connected in terms of flow to the valve system pressure chamber (18).
9. Ventil nach Anspruch 8, dadurch gekennzeichnet, daß das Material des Leckagestiftes (23, 23λ) einen derart größeren Wärmeausdehnungskoeffizienten als das Material des Ventilkorpers (9) aufweist, daß bei zunehmender Temperatur eine viskositatsbe- dingte Zunahme des den Leckagestift (23, 23λ) umströmenden Volumenstroms wenigstens teilweise begrenzt wird.9. Valve according to claim 8, characterized in that the material of the leakage pin (23, 23 λ ) such a larger one Thermal expansion coefficient as the material of the valve body (9), that with increasing temperature a viscosity-related increase in the volume flow flowing around the leakage pin (23, 23 λ ) is at least partially limited.
10. Ventil nach einem der Ansprüche 1 bis 9, dadurch gekennzeichnet, daß das den Ventilsystemdruckraum (18) begrenzende Dichtelement als faltenbalgartige Membran (25) ausgebildet ist, die derart mit dem Ventilglied (2) und mit dem Ventilkorper (9) verbunden ist, daß die piezoelektrische Einheit (3) vor einem Kontakt mit der zu steuernden Flüssigkeit geschützt ist.10. Valve according to one of claims 1 to 9, characterized in that the sealing element which delimits the valve system pressure chamber (18) is designed as a bellows-like membrane (25) which is connected in this way to the valve member (2) and to the valve body (9), that the piezoelectric unit (3) is protected from contact with the liquid to be controlled.
11. Ventil nach einem der Ansprüche 1 bis 10, gekennzeichnet durch seine Verwendung als Bestandteil eines Kraftstoffein- spritzventils für Brennkraf maschinen, insbesondere eines Common-Rail-Injektors (1). 11. Valve according to one of claims 1 to 10, characterized by its use as a component of a fuel injection valve for internal combustion engines, in particular a common rail injector (1).
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19946828 | 1999-09-30 | ||
DE19946828A DE19946828C1 (en) | 1999-09-30 | 1999-09-30 | Valve for controlling liquids |
PCT/DE2000/003136 WO2001023741A1 (en) | 1999-09-30 | 2000-09-09 | Valve for controlling fluids |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1135591A1 true EP1135591A1 (en) | 2001-09-26 |
Family
ID=7923811
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP00972589A Withdrawn EP1135591A1 (en) | 1999-09-30 | 2000-09-09 | Valve for controlling fluids |
Country Status (7)
Country | Link |
---|---|
US (1) | US6427968B1 (en) |
EP (1) | EP1135591A1 (en) |
JP (1) | JP2003510504A (en) |
KR (1) | KR20010101057A (en) |
CZ (1) | CZ20011880A3 (en) |
DE (1) | DE19946828C1 (en) |
WO (1) | WO2001023741A1 (en) |
Families Citing this family (31)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19939520C2 (en) * | 1999-08-20 | 2001-06-07 | Bosch Gmbh Robert | Injection system and method for operating an injection system |
DE10002270C1 (en) * | 2000-01-20 | 2001-06-28 | Bosch Gmbh Robert | Valve for controlling liquids has electronic control unit that defines piezoelectric valve element actuating unit drive voltage depending on leakage loss in low pressure region |
DE10019764B4 (en) * | 2000-04-20 | 2004-09-23 | Robert Bosch Gmbh | Length measuring device for measuring dimensions of bodies, particularly inner- and outer diameters, used in mechanical drive- and transmission elements and in circular body, has carrier element, which is adapted to body to be measured |
DE10019766A1 (en) * | 2000-04-20 | 2001-10-31 | Bosch Gmbh Robert | Valve for controlling liquids has solid body enclosed by gap in filler chamber, high pressure connection line at one end and leakage line at other, branch in line to hydraulic chamber |
DE10037388A1 (en) * | 2000-08-01 | 2002-02-21 | Bosch Gmbh Robert | Valve arrangement, in particular for a fuel injection system of an internal combustion engine |
DE10046662B4 (en) * | 2000-09-20 | 2004-09-30 | Robert Bosch Gmbh | Fuel injection valve with a pressure control valve |
DE10118053A1 (en) * | 2001-04-11 | 2002-10-24 | Bosch Gmbh Robert | Valve for controlling liquids e.g. for vehicle fuel injection system, has hydraulic chamber that transfers control piston movement to actuating piston, which is in hydraulic force equilibrium with valve element closed |
DE10131617A1 (en) * | 2001-06-29 | 2003-01-23 | Bosch Gmbh Robert | Fuel injector switching valve for pressure relief / loading of a control room |
DE10136186A1 (en) * | 2001-07-25 | 2003-02-06 | Bosch Gmbh Robert | Valve for controlling liquids, has transition region between second piston and intermediate piston arranged in region with lower pressure than in system pressure region |
US6595189B2 (en) * | 2001-08-10 | 2003-07-22 | Caterpillar Inc | Method of reducing noise in a mechanically actuated fuel injection system and engine using same |
DE10148594A1 (en) * | 2001-10-02 | 2003-04-10 | Bosch Gmbh Robert | Fuel injection valve has corrugated tube around guide sleeve with sealed connections to pistons that seals storage chamber for hydraulic fluid with respect to enclosing fuel chamber |
DE10157419A1 (en) * | 2001-11-23 | 2003-06-12 | Bosch Gmbh Robert | Leakage-reduced pressure supply for fuel injectors |
DE10160191A1 (en) * | 2001-12-07 | 2003-06-26 | Bosch Gmbh Robert | Fuel injector with remotely operated actuator, optimized system pressure supply has coupling chamber connected to high pressure side via shunt line, system pressure maintaining unit |
DE10162045B4 (en) * | 2001-12-17 | 2005-06-23 | Siemens Ag | Device for translating a deflection of an actuator, in particular for an injection valve |
DE10232193A1 (en) * | 2002-07-16 | 2004-02-05 | Robert Bosch Gmbh | Fuel injector |
DE10254749A1 (en) * | 2002-11-23 | 2004-06-17 | Robert Bosch Gmbh | Fuel injection device with a 3/3-way control valve for injection course shaping |
DE10332874A1 (en) * | 2003-07-19 | 2005-02-10 | Robert Bosch Gmbh | Hydraulic coupler and fuel injector |
DE102004027752A1 (en) * | 2004-06-08 | 2006-01-05 | Leybold Optics Gmbh | lock device |
EP1834078B1 (en) * | 2005-01-07 | 2011-03-23 | Delphi Technologies Holding S.à.r.l. | Fuel injection apparatus |
DE102005026967B4 (en) * | 2005-06-10 | 2014-09-25 | Siemens Aktiengesellschaft | Valve, in particular servo valve |
DE102005028601B4 (en) * | 2005-06-21 | 2007-08-23 | Volkswagen Mechatronic Gmbh & Co. Kg | Injection valve, in particular pump nozzle |
CA2600323C (en) * | 2007-09-20 | 2009-12-29 | Westport Power Inc. | Directly actuated valve with a strain-type actuator and a method of operating same |
US7885754B2 (en) * | 2007-12-07 | 2011-02-08 | General Electric Company | Fuel injection system and method of operating the same for an engine |
FI123386B (en) * | 2010-12-10 | 2013-03-28 | Waertsilae Finland Oy | Fuel injection device, piston engine and method of operating a piston engine |
DE102011079468A1 (en) * | 2011-07-20 | 2013-01-24 | Continental Automotive Gmbh | piezoinjector |
DE102012212614A1 (en) | 2012-07-18 | 2014-01-23 | Continental Automotive Gmbh | Piezo injector with hydraulically coupled nozzle needle movement |
DE102012222509A1 (en) | 2012-12-07 | 2014-06-12 | Continental Automotive Gmbh | piezoinjector |
CN102996838B (en) * | 2012-12-13 | 2015-07-08 | 浙江师范大学 | Intelligent large-flow electro-hydraulic valve |
DE102012223934B4 (en) | 2012-12-20 | 2015-10-15 | Continental Automotive Gmbh | piezoinjector |
US10570863B1 (en) | 2018-09-18 | 2020-02-25 | Caterpillar Inc. | Fuel injector having cam-actuated plunger and plunger cavity metering edge for valvetrain noise suppression |
KR102105949B1 (en) * | 2018-09-20 | 2020-05-06 | 인지컨트롤스 주식회사 | Solenoid valve for vehicle |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4560871A (en) * | 1983-12-22 | 1985-12-24 | Marquest Medical Products, Inc. | Actuator for control valves and related systems |
DE19624001A1 (en) * | 1996-06-15 | 1997-12-18 | Bosch Gmbh Robert | Fuel injection device for internal combustion engines |
US5779149A (en) | 1996-07-02 | 1998-07-14 | Siemens Automotive Corporation | Piezoelectric controlled common rail injector with hydraulic amplification of piezoelectric stroke |
DE19708304C2 (en) * | 1997-02-28 | 1999-09-30 | Siemens Ag | Movement transmission device and injection valve with a movement transmission device |
DE19709794A1 (en) * | 1997-03-10 | 1998-09-17 | Bosch Gmbh Robert | Valve for controlling liquids |
DE29708369U1 (en) * | 1997-05-09 | 1997-07-10 | FEV Motorentechnik GmbH & Co. KG, 52078 Aachen | Controllable injection valve for fuel injection on internal combustion engines |
DE19732802A1 (en) * | 1997-07-30 | 1999-02-04 | Bosch Gmbh Robert | Fuel injection device for internal combustion engines |
DE19742943C1 (en) * | 1997-09-29 | 1999-04-22 | Siemens Ag | Coupling device between actuator and valve setting element |
DE19746143A1 (en) * | 1997-10-18 | 1999-04-22 | Bosch Gmbh Robert | Valve for controlling liquids |
-
1999
- 1999-09-30 DE DE19946828A patent/DE19946828C1/en not_active Expired - Fee Related
-
2000
- 2000-09-09 EP EP00972589A patent/EP1135591A1/en not_active Withdrawn
- 2000-09-09 CZ CZ20011880A patent/CZ20011880A3/en unknown
- 2000-09-09 JP JP2001527099A patent/JP2003510504A/en active Pending
- 2000-09-09 WO PCT/DE2000/003136 patent/WO2001023741A1/en not_active Application Discontinuation
- 2000-09-09 US US09/831,219 patent/US6427968B1/en not_active Expired - Fee Related
- 2000-09-09 KR KR1020017006488A patent/KR20010101057A/en not_active Application Discontinuation
Non-Patent Citations (1)
Title |
---|
See references of WO0123741A1 * |
Also Published As
Publication number | Publication date |
---|---|
DE19946828C1 (en) | 2001-07-12 |
KR20010101057A (en) | 2001-11-14 |
WO2001023741A1 (en) | 2001-04-05 |
JP2003510504A (en) | 2003-03-18 |
CZ20011880A3 (en) | 2002-04-17 |
US6427968B1 (en) | 2002-08-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
DE19946828C1 (en) | Valve for controlling liquids | |
EP1185787B1 (en) | Valve for controlling liquids | |
DE19946833C2 (en) | Valve for controlling liquids | |
DE19946827C1 (en) | Valve for controlling liquids | |
DE10001099A1 (en) | Control valve for injector of fuel injection system for internal combustion engine; has regulator connected to pressure piston to separate control chamber from control valve and increase pressure | |
DE19946831C1 (en) | Valve for controlling liquids | |
DE10019765B4 (en) | Valve for controlling liquids | |
DE10019764B4 (en) | Length measuring device for measuring dimensions of bodies, particularly inner- and outer diameters, used in mechanical drive- and transmission elements and in circular body, has carrier element, which is adapted to body to be measured | |
WO2001023747A1 (en) | Valve for controlling liquids | |
WO2001081755A1 (en) | Valve for regulating fluids | |
EP1276983B1 (en) | Valve for controlling liquids | |
WO2002020978A1 (en) | Hydraulically translated valve | |
WO2002029254A2 (en) | Valve for controlling fluids | |
DE19939478C1 (en) | Valve for regulation of fluids, e.g. for fuel injection valves has separate hydraulic converter with third piston element between pressure chambers | |
EP1360407A2 (en) | Valve for controlling liquids | |
EP1165956A1 (en) | Valve for controlling liquids | |
WO2004018865A1 (en) | Valve for controlling liquids | |
DE10152253A1 (en) | Valve for controlling liquids |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE |
|
17P | Request for examination filed |
Effective date: 20011005 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20040401 |