DE102011121384A1 - Injector e.g. common rail fuel injector for e.g. diesel engine of vehicle, has actuators with actuating units which are displaced with respect to each other in specific directions - Google Patents

Abstract

The injector (1) has pilot valve (7) which is controlled by actuating unit (8) of first actuator (9) in open position, closed position and partially opened intermediate position. The actuating unit (8) and actuating unit (17) of second actuator (16) of injector are mechanically decoupled from each other in specific directions in response to pilot valve position. The actuating units of injector are displaced with respect to each other in opposite directions. The actuating units are self-resettable from the decoupled positions in opposite directions. An independent claim is included for method for manufacturing injector.

Description

The present invention relates to an injector for a fuel injection device according to the preamble of claim 1.

In the prior art, a fuel injector is known whose solenoid valve cooperates with another solenoid to enable switching of solenoid valve lift stages. As part of the switching of the lifting stages a gate valve is moved in response to excitation or de-excitation of the other solenoid. Such a solution shows z. B. the publication DE 696 26 097 T2 which the WO 97/008452 underlying.

The magnetically coupled to the other solenoid gate valve is supported here with a collar on a return spring, which on the other hand is supported on a magnetically magnetically coupled to the solenoid of the valve valve disc. This mechanical coupling via the return spring leads to an adverse susceptibility to vibration of the system.

A disadvantage of the known solution is further that the known arrangement is limited in terms of their functional stock, in particular insofar as the permanent taking a Teilhubstellung is not possible without a continuous energization of the other solenoid.

Proceeding from this, the present invention seeks to propose an injector, which overcomes the above-described disadvantages of the prior art.

This object is achieved by the features of claim 1. Advantageous developments and embodiments are specified in the subclaims.

The invention proposes an injector for a fuel injection device, in particular a common rail system, wherein the injector is generally provided for use with internal combustion engines in the form of gasoline or diesel engines, in particular vehicle engines, z. In off-road or marine applications.

The injector may be connected to the inlet side Kraftstoffbeaufschlagung with a pressure accumulator or a high pressure feed device, for. B. a fuel pump. To deliver the high-pressure fuel, the injector has a fuel dispenser, preferably a nozzle arrangement.

According to the invention, the injector comprises a pilot valve or control valve which can be actuated via an actuator of a first actuator of the injector, wherein the first actuator z. B. may be a piezoelectric actuator or preferably a magnetic actuator. The pilot valve is provided to suitably adjust or influence the pressure in a control chamber of the injector, in particular by relieving it in order to control a nozzle needle of the injector via the pressure conditions in the control chamber, i. e. their hub. For this purpose, in particular an outlet throttle on the part of the control chamber can be flowed through via the pilot valve.

The pilot valve is controllable in the context of the present invention via the actuator of a first actuator in an open position, a closed position and a partially open intermediate position, wherein the opening cross-section is reduced in the intermediate position relative to that of the open position, wherein a throttle effect can be achieved.

According to the invention, the injector on a second actuator with an actuator, which may also be formed as a piezo actuator or preferably as Magnetaktuator (woneben other actuator forms are conceivable), wherein the actuator of the first and the actuator of the second actuator in response to a valve position to be adopted by each other mechanically decoupled in particular opposite directions tax and against each other are displaced. Furthermore, the first and second actuator are in particular also in opposite directions mechanically decoupled from each other self-recoverable. By providing two mechanically decoupled actuators, it is advantageously possible according to the pilot valve to take and hold valve positions unaffected by the actuator of the further actuator by means of the actuator of the first actuator, i. e. largely free of vibration.

Advantageously, in the context of the present invention, this opens up the possibility of designing an injector such that the actuator of the first actuator is controlled or reset in any position of the pilot valve against a fixed stop and thus into a permanently stable position. A stop for the actuator of the first actuator in the open position of the pilot valve can be advantageously uncomplicated by the actuator body itself, z. B. a magnetic packet may be formed, a stop for the closed position preferably through the valve seat, alternatively z. B. the injector. Alternatively, it may be provided for each specially formed for this purpose stops.

In particular, the actuator of the second actuator in the intermediate position of the pilot valve form the fixed stop for the actuator of the first actuator. To take the intermediate position of the pilot valve, the actuators of the actuators are controlled against each other in contact with each other shifts, ie by energizing the respective actuators. The actuator of the second actuator is also controlled in this case in a permanently stable position, ie preferably before the first actuator is activated.

Provided here is to control the actuator of the second actuator against another stop or to relocate, which is advantageously unobtrusive preferably formed by the actuator body of the second actuator itself, z. B. a magnetic package, alternatively z. B. against a separately formed stop. The provision of the intermediate position is provided in particular from respective reset positions.

By measures proposed above, the tendency of the system to oscillate can be further reduced when defining stable positions for the actuators, in particular an advantageously stable intermediate position.

In the defined intermediate position, the pilot valve, as already noted, represent a further resistance to the outlet throttle. This is particularly advantageous for the precise allocation of smallest injection quantities, for which a flat flow rate characteristic in the front ballistic nozzle needle area is required. In the context of the present invention, it has been recognized that a flattening of the characteristic curve can be achieved by a moderate, even slow opening of the nozzle needle, in particular combined with a fast closing. By providing a defined intermediate position, a reproducibly higher flow resistance for the medium to be displaced in the control chamber can be achieved, so that the control chamber empties more slowly, d. H. the nozzle needle advantageously opens slowly. From the intermediate position of the pilot valve, which corresponds to a Teilhubstellung of the actuator of the first actuator, the pilot valve can also close quickly.

While the actuators for controlled displacement of the actuators can be energized, in the case of using magnetic actuators preferably for generating a magnetic force which can act on the actuators, is provided for taking the reset positions or for self-provision, the actuators preferably each with at least one spring element to burden, in particular by means of a separate spring. The springs are preferably coil springs, in particular helical compression springs, woneben z. B. also elastomeric materials are conceivable.

In the context of the present invention, a reset position can be assumed here, in particular independently of the further actuator, if the respective actuator is de-energized or deactivated.

In accordance with a further aspect of the invention, the injector is designed to shift the actuator of the second actuator in a controlled manner against the actuator of the first actuator, compared to the prior art, by accelerating taking a closed position of the pilot valve, in particular proceeding from the open position of the pilot valve , e. such that a force acts against the first actuator in the closing direction. As a result of the resulting greatly accelerated assumption of the closed position, an improved minimum quantity capability of the injector can be formed insofar as a flatter flow rate characteristic curve can be achieved.

In particular, in the context of the use of Magnetaktuatoren here is provided to energize the second actuator already at a time at which the first actuator is still activated, d. H. whose actuator is in a Vollhubstellung. Thus, after elimination of the energization of the first actuator, in particular a self-induction-induced release resistance, which its actuator learns by providing a biasing force can be overcome quickly.

It is preferably provided here that the force, in particular a magnetic force, by means of which the actuator of the second actuator is urged or displaced to take the closed position against the first actuator, is significantly greater, for. B. by a factor> 2, as one on the actuator of the first actuator, i. e. in the open position, acting self-restoring force, with a high biasing force can be achieved.

In the context of the present invention, a method is also proposed for execution with an injector as described above, wherein the actuator of the second actuator is displaced controlled against the actuator of the first actuator to accelerate overcoming the release resistance, which experiences the first actuator in the open position , in particular before a deactivation of the first actuator.

It is further provided that the pilot valve is controlled to deliver small amounts to the intermediate position, wherein the pilot valve acts in particular as a throttle.

Further features and advantages of the invention will become apparent from the following description of embodiments of the invention, based the figures of the drawings showing essential to the invention, and from the claims. The individual features can be realized individually for themselves or for several in any combination in a variant of the invention.

Exemplary embodiments of the invention are explained below with reference to the accompanying drawings. Show it:

1 an example and schematically a broken view of an injector according to a possible embodiment of the invention;

2a to 2c exemplary and schematic views illustrating the interaction of the first and second Akutators or their actuators according to a possible embodiment of the invention; and

3 exemplary and schematically the course of each flow rate characteristic for an open position and the defined intermediate position of the pilot valve.

In the following description and the drawings, the same reference numerals correspond to elements of the same or comparable function.

The 1 shows a broken view of an injector 1 for a fuel injection device, in particular an internal combustion engine of a motor vehicle. The injector 1 includes a housing 2 , inside which a nozzle needle 3 is arranged, whose stroke, inter alia, on the pressure conditions in a control room 4 can be adjusted. The nozzle needle 3 opens or closes the discharge openings of a fuel dispenser 5 of the injector 1 , which is preferably formed by means of at least one nozzle, depending on their stroke selectively.

With the control room 4 in fluid communication is an outlet throttle 6 , which has a pilot valve 7 of the injector 1 as a function of which position can be flowed through. It can be seen corresponding to the respective valve position of the pilot valve 7 thus a pressure ratio in the control room 4 and thus the stroke of the nozzle needle 3 be controlled or adjusted.

The pilot valve 7 is about an actuator 8th a first magnetic actuator 9 of the injector 1 operable, which with a control rod 10 is formed. The control rod 10 forms the valve member 11 the pilot valve 7 which is spherically formed, wherein alternatively conceivable, a valve member 11 indirectly via the control rod 10 or the actuator 8th to press. The valve member 11 acts with a valve seat 12 the pilot valve 7 together, which is correspondingly formed in the form of a hollow cone.

To the valve 7 starting from the in 1 shown position, which in the context of the present invention, the closed position of the pilot valve 7 corresponds, by means of the first actuator 9 or its actuator 8th to be able to control in an open position, which in the context of the present invention, a full or maximum stroke position of the actuator 8th corresponds, 2c , assigns the actuator 8th Furthermore, a parking plate or an anchor 13 on which at the control rod 10 is fixed.

The parking plate 13 is suitable for a controlled displacement of the actuator 8th with a magnetic package 14 of the first actuator 9 acting together, which is formed by means of a solenoid or an electromagnet, and provides an actuator body. When energized, ie activation of the first actuator 9 can the parking plate 13 and thus the control rod 10 , ie, the actuator 8th , by the adjusting magnetic force of the magnetic packet 14 of the actuator 8th be tightened, ie the pilot valve 7 open, with the actuator 8th in the direction of the valve seat 12 towards the magnetic package 14 emotional. As 1 it can be seen, is the magnetic package 14 , which forms an actuator body, in this case immovably on the injector 1 supported, ie the housing 2 ,

The first actuator 9 also has a return spring 15 in the form of a helical compression spring, which for self-return of the actuator 8th is provided and which at - in particular controlled - elimination of the energization of the actuator 9 , ie deactivating it, the actuator 8th towards the valve seat 12 relocated. This way, the pilot valve can 7 take the closed position de-energized and hold, 2c , The return spring 15 is on the one hand at a fixed point in the injector 1 , in particular on the housing 2 , and on the other hand on the shelf 13 supported.

Like that 1 to 2c can still be seen, the injector 1 a second actuator 16 with an actuator 17 on, by means of which the pilot valve 7 can be controlled in a partially opened, in particular defined intermediate position, 2 B , The intermediate position corresponds to a partial stroke position of the actuator 8th of the first actuator 9 in which the pilot valve 7 opened but not fully opened.

Corresponding to the formation of the first actuator 9 also indicates the actuator 17 of the second actuator 16 an adjusting rod 18 on and a fixed thereto anchor or a control plate 19 , Also corresponding to the actuator 9 points the second actuator 16 a magnetic package 20 on, which in turn is formed by means of a solenoid or an electromagnet. Like that 1 to 2c it can be seen, is the second actuator 16 compared to the first actuator 9 in particular smaller dimensions, which allows shorter response times when activated.

The parking plate 19 is intended for energization or activation of the second actuator 16 towards its magnetic package 20 ie towards the valve seat 12 be attracted, ie magnetically, wherein the actuator body 20 again suitable at the injector 1 is immovably supported, in particular its housing 2 , In other words, the actuator 17 of the second actuator 16 energized in one direction, + A, controlled displaceable, which is opposite to the direction, -A, set in which the actuator 8th controlled controlled during control or energization. Here are the adjusting rods 10 and 18 coaxially aligned and brought in the course of a shift against each other to the plant.

For a self-resetting of the actuator 17 in particular controlled removal of the energization or deactivation of the second actuator 16 points the second actuator 16 a return spring 21 again in the form of a helical compression spring. The helical compression spring 21 is on the one hand at a fixed point in the injector 1 , in particular on the housing 2 , and on the other hand on the shelf 19 supported.

Now again in particular with reference to the 1 such as 2a to 2c becomes the functionality of the injector 1 explained in more detail.

Starting from a in 1 and 2a shown closed position, the pilot valve 7 of the injector 1 in an intermediate position according to 2 B or in an open position according to 2c be controlled, including the actuator 8th of the first actuator 9 each controlled is relocatable or is relocated. It is remarkable in the context of the present invention that the actuator 8th of the first actuator 9 in all positions of the pilot valve 2 , ie, in the closed position, the intermediate position and the open position, advantageously in permanently stable positions can be brought, in particular ever in contact with a stop element. In this way, the tendency to oscillate is minimized.

In the closed position according to the 1 and 2a is the actuator 8th of the first actuator 9 by the return spring 15 self-resetting in the direction of the valve seat 12 urged while the first actuator 9 is de-energized. The actuator 8th gets into abutment against a stop 22 passing through the valve seat 12 is formed. The second actuator 16 is also de-energized, with its actuator 17 through the further return spring 21 in the return direction + A of the first actuator 8th opposite direction -A is reset. The actuators 8th respectively. 17 are not in contact with each other.

Now to take the intermediate position, z. B. to dose small amounts, 2 B , first becomes the second actuator 16 energized, whereby in the course of the onset of magnetic force, the magnetizable actuator plate 19 and thus the actuator 17 towards the valve seat, ie towards + A against a stop 23 is attracted, which the stationary arranged magnetic packet 20 forms. The actuator 17 thereafter remains magnetically conditioned in a stable position.

In a subsequent energization of the first actuator 9 , in the course of which now the parking plate 13 of the actuator 8th from the magnetic package 14 is tightened, ie in the direction -A, forms the control rod 18 Consequently, due to their magnetic locking a firm stop 24 for the control rod 10 the first actuator which abuts against it in the course of the controlled displacement, 2 B ie the actuator 17 forms a positive stop for the actuator 8th and thus defines the intermediate position of the pilot valve 7 ,

Be seen here in the context of the present invention from each other mechanically decoupled actuators 8th . 17 for taking the intermediate position of each other actuator 17 . 8th unaffected or independently relocated.

To take the open position starting from the intermediate position, z. B. 2c , can the energization of the second actuator 16 are set, whereupon the return spring 21 the actuator 17 shifted to the reset position, ie the fixed stop 24 from the actuator 17 moved away. Now, the first actuator 8th through the energized magnetic package 14 magnetic force unhindered occupy the Vollhubstellung, ie in turn mechanically decoupled. It should be noted that the open position can also be taken directly from the closed position, including the second actuator 16 remains energized. Like from the 2c it can be seen, the first actuator passes 8th also in the open position in contact with a stop 25 , ie the magnetic package 14 , so that a fixed stop for the first actuator is available for all stroke positions or valve positions.

To the pilot valve 7 advantageous to quickly transfer from the open position to the closed position, is the injector 1 beyond that, the actuator is designed 17 of the second actuator 16 controlled against the actuator 8th of the first actuator 9 to relocate. By providing a biasing force or a pulse, a release resistor, which the actuator 8th of the first actuator 9 learns to be overcome faster. To accelerate taking the closed position is the second actuator 16 preferably already energized, while also the first actuator 9 still energized. As a result, the actuator passes 17 in contact with the actuator 8th and applies to this a force which acts in the closing direction + A and which is suitable, the release resistance, which the actuator 8th must overcome, after adjusting the energization of the first actuator 9 to overcome faster.

In particular, it is provided that the second actuator 16 generates a magnetic force which is significantly greater than one on the actuator 8th of the first actuator 9 acting self-restoring force.

To control the first 9 and second actuator 16 is provided in the context of an electrical series connection, that the internal resistance of the second magnetic packet 20 is so low that at a normal Bestromungsprofil, z. B. with a boost / holding current, only the first actuator 9 is operated starting from the closed position, ie corresponding to a full stroke.

To activate the partial stroke, the normal boost current may be preceded by a "boost peak", which is the second actuator 16 activated. Since this in the context of the present invention, preferably smaller and lighter than the first actuator 9 is, arrives its actuator plate 19 in plant, before the actuator 8th of the first actuator 9 on the actuator 17 of the second actuator 16 meets. Advantageously, in this case only one supply line is required.

Alternatively it can be provided, the actuators 9 . 16 independently to activate or to control. For this purpose, the actuators 9 . 16 or their magnetic packages 14 . 20 each have their own electrical connection, which high flexibility can be achieved. For example, a switching operation can be carried out in two stages if, after reaching the intermediate position from the closed position, the second actuator 16 is deactivated. Conversely, when closing from the open position or full stroke during deactivation of the first actuator 9 the second actuator 16 be activated to the actuator 8th to impose an additional closing impulse.

By the described training of the injector 1 in which the actuators 9 . 16 one unaffected by the other actuator 8th . 17 independently controlled displaceable and resettable actuator 17 . 8th have, ie mutually mechanically decoupled actuators, insofar as regards their actuators 9 . 16 an independent or mutually mechanically decoupled movement is made possible, in which the first actuator 8th In addition, in any valve position in a stable position can be moved, is the injector 1 able to take and maintain the valve positions with little vibration.

3 shows exemplary characteristic curves, as these result in dependence on the valve position, wherein the injection amount is indicated over the Bestromungsdauer. As 3 can be seen, results in partial lift TH and the partially opened intermediate position a flatter characteristic curve over that at full lift VH and the open position. This clarifies that an improved minimum quantity capability in the partial stroke can be achieved as described above.

By means of the invention, a leveling of the nozzle needle opening and closing characteristics over a large injection pressure range can be achieved. The emptying of the control chamber, due to the combustion chamber side acting on the needle, greatly different system pressure can be controlled by the position or Hubumschaltung the pilot valve such that the nozzle needle opens at high pressure almost as fast and closes as at low system pressure.

LIST OF REFERENCE NUMBERS

1

injector

2

casing 1

3

nozzle needle 1

4

control room 1

5

Krafstoffabgabevorrichtung 1

6

outlet throttle

7

pilot valve 1

8th

actuator 9

9

first actuator 1

10

control rod 9

11

valve member 7

12

valve seat 7

13

adjusting plate 8th

14

magnet set 9

15

feather 9

16

second actuator 1

17

actuator 16

18

control rod 16

19

adjusting plate 17

20

magnet set 16

21

feather 16

22

attack

23

attack

24

attack

25

attack

+ A, -A

directions

TH

partial stroke

VH

Full lift

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 69626097 T2 [0002]
• WO 97/008452 [0002]

Claims (10)

Injector ( 1 ) for a fuel injection device, wherein the injector ( 1 ) a pilot valve ( 7 ), which via an actuator ( 8th ) of a first actuator ( 9 ) of the injector ( 1 ) in an open position, a closed position and a partially open intermediate position is controllable, characterized in that the actuator ( 8th ) of the first and an actuator ( 17 ) of a second actuator ( 16 ) of the injector ( 1 ) in response to a valve position to be taken mechanically decoupled from each other in particular opposite directions (+ A, -A) tax and against each other are displaced and in particular opposite directions (-A, + A) mechanically decoupled from each other self-resettable. Injector ( 1 ) according to claim 1, characterized in that the actuator ( 8th ) of the first actuator ( 9 ) in any position of the pilot valve ( 7 ) against a fixed stop ( 22 . 24 . 25 ) and thus taxable or recoverable in a permanently stable position. Injector ( 1 ) according to claim 2, characterized in that the actuator ( 17 ) of the second actuator ( 16 ) in the intermediate position of the pilot valve ( 7 ) the fixed stop ( 24 ) for the actuator ( 8th ) of the first actuator ( 9 ). Injector ( 1 ) according to one of the preceding claims, characterized in that the actuators ( 8th . 17 ) of the actuators ( 9 . 16 ) in the intermediate position of the pilot valve ( 7 ) are displaced against each other in abutment against each other, in particular from respective reset positions, wherein the actuator ( 17 ) of the second actuator ( 16 ) is controlled in a permanently stable position, in particular against a stop ( 23 ) on the second actuator ( 16 ). Injector ( 1 ) according to one of the preceding claims, characterized in that the injector ( 1 ) is formed, in particular accelerated taking the closed position, the actuator ( 17 ) of the second actuator ( 16 ) controlled against the actuator ( 8th ) of the first actuator ( 9 ) to relocate. Injector ( 1 ) according to one of the preceding claims, characterized in that at least one actuator ( 9 . 16 ) is a Magnetaktuator, in particular all, or a piezoelectric actuator. Injector ( 1 ) according to one of the preceding claims, characterized in that the actuators ( 8th . 17 ) are each spring-loaded for self-resetting, in particular by means of one each opposite the spring ( 15 . 21 ) of the further actuator ( 17 . 8th ) separate spring ( 21 . 15 ). Injector ( 1 ) according to claim 5 to 7, characterized in that a force, in particular a magnetic force, by means of which the actuator ( 17 ) of the second actuator ( 16 ) for taking the closed position against the actuator ( 8th ) of the first actuator ( 9 ) is greater than one on the actuator ( 8th ) of the first actuator ( 9 ) acting self-restoring force. Method of execution with an injector ( 1 ) according to one of the preceding claims, characterized in that in the course of taking the closed position of the pilot valve ( 7 ) for overcoming the release resistance, which the actuator ( 8th ) of the first actuator ( 9 ) in the open position, the actuator ( 17 ) of the second actuator ( 16 ) against the actuator ( 8th ) of the first actuator ( 9 ) is controlled, in particular before deactivation of the first actuator ( 9 ). Internal combustion engine, characterized by an injector ( 1 ) according to one of claims 1 to 8.

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