DE102012012890B4 - injector - Google Patents

Abstract

Injector (1) with a solenoid actuator operated pilot valve (2), wherein the armature (7) of the actuator (3) in an armature space (9) on the injector (1) for displacing the valve member (12) of the pilot valve (2) is movable the injector (1) is designed to introduce pressurized gas into the armature space (9) in order to counteract leakage which can enter the armature space (9) via a leakage path, the injector (1) comprising at least one leakage discharge line (20, 29 ), via which the compressed gas and / or by means of the compressed gas displaced leakage from the armature space (9) can be discharged.

Description

The present invention relates to an injector.

Electromagnetically actuated injectors with pilot valve have the magnetic coil or the magnetic core of the actuator positioned as close to the nozzle to the moving masses low and the hydraulic paths to the control room, i. e. above the nozzle needle, to keep it short. In this case, it is regularly unavoidable that magnet and armature plate of the actuator are surrounded due to leakage at the anchor rod guide of fuel, whereby a movement of the armature plate is prevented by a high hydraulic resistance.

To reduce the hydraulic resistance, it is in the prior art from the document DE 10 2009 022 538 A1 , which relates to an electromagnet, is known to provide the armature with a penetration opening. However, flowable medium must also be moved during a displacement of the armature, accompanied by a limitation of the maximum possible displacement speeds of the armature and insofar the valve opening or closing speeds.

From the publication DE 36 90 391 T5 In addition, an injector is known, upon actuation of which a metered amount of fuel is delivered via pressurized air to an engine combustion chamber.

Proceeding from this, the object of the present invention is to provide an injector which overcomes the disadvantages of the prior art and enables an optimized pilot valve opening or closing characteristic, in particular a shortening of the opening or closing duration of a pilot valve which can be selectively opened via the armature.

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

According to the invention, an injector is proposed, in particular for a fuel injection device, furthermore in particular of a motor vehicle. The respective injector may preferably be provided for use in a common rail system, in particular also each having a single pressure accumulator, the injector is generally provided for use with internal combustion engines in the form of gasoline or diesel engines, especially large diesel engines and further in particular vehicle engines, z , In off-road or marine applications. Particularly preferably, the injector can be used with ships or commercial vehicles.

The proposed injector comprises a magnetaktuatorbetätigtes valve, wherein the armature of the actuator, preferably in the form of an anchor plate, in an armature space on the injector for displacing the valve member is movable. The armature space may preferably be formed in a valve housing of the injector, alternatively z. B. in a pressure accumulator housing or a different housing element of the injector. The magnetic packet of the actuator may be arranged adjacent to the armature space, in particular in a magnet space provided for this purpose. The armature in the armature space can be displaced in this case via the selectively energisable magnetic packet-preferably furthermore via a spring load provided by the actuator-and a valve member can thus be displaced via the armature in this respect. Magnetic space and armature space preferably together form a space or a volume.

According to the invention, the valve is a control valve or pilot valve of the injector. In the context of the present invention, the injector with a pressure unbalanced or pressure-loaded or with a non-pressure-loaded or pressure-balanced (solenoid) valve, z. B. formed as a 2/2-way valve, be executed. In the present case, a pressure-loaded valve is in particular a valve, on the valve member of which, when the high pressure or system pressure is present, acts on the injector in the closed position, axial pressure forces, d. H. in the opening direction of the valve member. In contrast, a pressure-compensated valve, in particular, denotes a valve whose valve member does not experience any axially effective pressure forces in the closed position.

About such a valve, the pressure conditions can be placed in a control chamber for the nozzle needle, generally their movement between open and closed positions are controlled with respect to a nozzle valve formed therewith. For this purpose, the valve member can interact with a valve seat in order to selectively release a flow path to the control chamber, which can be formed in a nozzle body of the injector, in particular to relieve the control chamber. Preferably, the valve member cooperate with a valve seat in the manner that results in a linear sealing contour.

The displaceable by means of the armature valve member or closing element is formed or provided in particular on an anchor rod or by or by the anchor rod, more particularly at one end thereof. The valve member may form an annular sealing edge, for. B. in a pressure balanced valve. The valve member may be spherical or conical or on it be executed in various ways, for. B. at a druckunausgeglichenen valve, z. B. also flat. The anchor rod is preferably received in an anchor rod guide and displaceable therein, in particular in the axial displacement direction of the nozzle needle, wherein the anchor rod guide can also be formed in the valve housing or in the injector.

In order to allow in particular an advantageously fast movement of the armature in the armature space - along with shortened opening and closing times of the valve - in particular in the context of the intended operation of the injector, the injector is inventively designed for introducing pressurized gas into the armature space to against filling , in particular leakage, to act, in particular to drain or dry out the anchor space. As a result, a hydraulic resistance based on the leakage, which could otherwise experience the armature when moving in the armature space, reduced or minimized. Incorporated pressurized gas can act against leakage, which can occur, for example via the anchor rod guide in the armature space.

For introducing pressurized gas into the armature space, a compressed gas flow channel, in particular in the form of at least one bore, is preferably formed in the injector. About this, the armature space preferably communicate with a compressed gas inlet at the injector, which is for connection to a compressed gas, preferably a compressed air source, provided. In a preferred embodiment, a check valve in the compressed gas flow channel is arranged to preclude leakage affects a compressed gas supply.

According to the invention, the injector is further designed to remove introduced compressed gas via at least one leakage discharge line from the armature space, in particular by means of the compressed gas displaced leakage. It can be provided to discharge both compressed gas and leakage via a leakage discharge line from the anchor space, d. H. together, so that the injector is inexpensive to produce. The at least one leakage discharge line preferably discharges at a valve-side end, in particular at the downstream end, of the armature space.

In the context of the present invention, it is preferably also provided to design the injector in such a way that pressurized gas can be introduced into the armature space via a magnet space, wherein the magnet space communicates in particular with the armature space. In this way, filling medium or leakage, in particular in the form of fuel, can also be displaced out of the magnetic space or the entry into the same can be prevented, i. e. Both the armature space and the magnetic space can be drained by means of compressed gas.

A pressurized gas flow channel, in particular in the form of at least one bore, is in this case guided to the magnet space, so that the armature space can be acted upon by pressurized gas from the magnet space.

Also proposed is a device, in particular for a motor vehicle, wherein the device has at least one injector as described above, in particular also a plurality of injectors. The device preferably forms a fuel injection system. In general, the device is designed in particular for the pneumatic flow of the armature space of the at least one injector in order to act against the filling medium or leakage.

To be able to displace filling medium from the respective armature space or to prevent it from entering it, i. e. by means of sealing air, the device has at least one compressed gas source, for. B. also two or more sources of compressed gas. About the at least one compressed gas source, in particular a compressed air source, a respective armature space can be flowed or acted upon with compressed gas. Also, the device may provide suitable flow paths which are communicated to respective pressurized gas inlets, i. H. at Druckgasströmungskanäle respective injectors, are connected or connected.

Preferably, the respective armature space can be selectively flowed over by the device. For this purpose, the device may be designed to be able to activate the compressed gas source in particular by a control or regulating device, for. B. via one or more controllable valves, in particular also to set a desired pressure gas pressure level in the respective armature space.

The device can preferably be designed to prevent filling medium from entering a respective armature space, i. e. by means of sealing air, in particular during a first operating state of the injector and / or be designed to displace filling medium by means of introduced into the armature space compressed gas from the respective armature space, in particular during at least a second operating state of the injector.

The injector or the device are preferably usable in a motor vehicle, in particular a ship or a utility vehicle, in particular with those which provide an onboard compressed gas source. The on-board compressed gas source is within the scope of the present invention for the pneumatic flow of an armature space provided at least one injector. The compressed gas source can be used in ships z. B. by a compressed air network in commercial vehicles z. B. be provided by the compressed air braking system.

Further features and advantages of the invention will become apparent from the following description of embodiments of the invention, with reference to the figures of the drawings, which show details 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.

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

1a an example of a schematic diagram of a structure of an injector according to a first possible embodiment of the invention;

1b an example of a schematic diagram of a structure of an injector according to a second possible embodiment of the invention;

2 exemplary and schematically a device with an injector according to a possible embodiment of the invention.

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

1a shows an injector 1 with a magnetaktuatorbetätigten, in particular not depressurized or not pressure balanced valve 2 , in particular in the form of a pilot or control valve 2 ,

The magnetic actuator 3 of the solenoid valve 2 is by means of a magnet package 4 formed, which in an injector 5 of the injector 1 , z. B. in the form of an accumulator housing, is received, ie in a magnetic space 6 , Furthermore, the actuator has 3 an anchor 7 in the form of an anchor plate, which in the axial direction, s. double arrow 8th in an anchorage 9 is relocatable.

With the anchor 7 firmly connected is an anchor rod 10 of the actuator 3 which in an anchor rod guide 11 at the injector 1 is guided. The anchor rod guide 11 is designed as a bore, which with the armature space 9 communicates, these being different from the anchor space 9 extends in the axial direction.

At the end of the anchor rod 11 , ie from the anchor room 9 Pointing away is a valve member 12 arranged to be with a corresponding valve seat 13 to cooperate, ie the pilot valve 2 to build.

The valve 2 can due to energization of the actuator 3 open, with the anchor plate 7 from the magnetic package 4 tightened and the closing force of a compression spring 14 of the actuator 3 is overcome. In de-energized state urges the compression spring 14 , which against the anchor 7 acts, the valve member 12 in the closed position, ie against the seat 13 ,

About the pilot valve 2 becomes the displacement or displacement of a nozzle needle 15 of the injector 1 , which in a nozzle body 16 of the injector 1 is included, ie together with a nozzle spring 17 and one the control room 18 defining sleeve 19 , For selectively opening the nozzle valve causes, ie in the context of the intended injection operations.

When opening the pilot valve 2 can the control room 18 of the injector 1 depressurized by high pressurized fuel from the control room 18 is controlled, ie one with the control room 18 communicating leakage discharge line or Absteuerleckageleitung 20 and the pilot valve 2 , The tailpipe leakage line 20 is through the pilot valve 2 selectively interruptible. Will the pilot valve 2 opened, is a fuel flow path over a first, in relation to the valve 2 upstream section 20a the line 20 which with the control room 18 communicates, and about another section 20b downstream of the valve 2 opened, allowing a discharge of the control room 18 via outflowing fuel (to a supply) is possible.

In the course of the pressure relief, the nozzle needle 15 this from the needle seat 21 take off and over the high pressure line 22 to the needle seat 21 leaked fuel from the spray holes of the nozzle emerge. The fuel is from a high-pressure accumulator 23 , z. B. a rail or a single pressure accumulator, wherein a quantity limiting valve 24 in the high pressure line 22 is provided.

When the valve is closed 2 is the next section 20b in the flow path through the valve 2 locked, ie a communication of the sections 20a and 20b prevented. In the control room 18 can high pressure over the high pressure line 22 and a branch 25 be built so that the nozzle needle 15 in the seat 21 urged, a fuel delivery or injection is thus prevented. In the closed position, the valve member 12 in this case at applied high pressure over the line section 20a (high) pressure loaded, ie in the opening direction 8th , throttle 37 control in the context of opening and closing operations.

About the anchor rod guide 11 is a leakage path in the injector 1 opens, ie in the sense of a creep path, over which leakage, ie highly pressurized fuel from the pilot valve 2 in the anchor room 9 can reach, ie the anchor space 9 can fill. Leakage is in this case in an annular gap between the wall of the guide 11 and the anchor rod 10 crowded.

To the anchor room 9 to be able to drain, ie the hydraulic resistance, the anchor plate 7 during a movement in the anchor room 9 otherwise could learn to lower, especially to eliminate, points the injector 1 a compressed gas line or a compressed gas channel 26 on which of an inlet 27 at the injector 1 to the magnet room 6 is guided. About the compressed gas channel 26 can the anchor space 9 - via the communicating with this magnetic space 6 - With compressed gas, in particular compressed air, flowed through, in particular also flows through, so that leakage from the armature space 9 both displaced and prevented from entering it. In the compressed gas channel 26 Here is a check valve 28 upstream of the magnetic space 6 arranged, which can prevent fuel or leakage enters the compressed gas supply system. The check valve is closed when no pressurized gas to the armature space 9 is supplied.

Leakage from the armature room 9 , which by means of the anchor space 9 introduced compressed gas is displaced, this case on the leadership 11 and the leakage discharge line 20 of the injector 1 dissipated, in particular their section 20b which one over the leadership 11 with the anchor room 9 communicated. In addition, a (in 1a dashed lines shown) additional leakage discharge line 29 be provided, which with the anchor space 9 on the one hand and with the leakage discharge line 20 or their section 20b on the other hand communicates. About the leak discharge line (s) 20 (and 29 ), the compressed gas can be advantageously removed in this case. Preferably, the optional leakage line branches or opens 29 at the armature end of the armature guide 11 from this, ie such that a lubrication of the anchor rod 10 is guaranteed, or alternatively z. B. at a valve-side end of the armature space 9 from the same.

According to 1a points the injector 1 still a check valve 30 which is in a separate leakage line 31 is arranged, which with the magnetic space 6 and the leakage discharge line 20 respectively. 20b communicated. This arrangement is suitable to prevent the fuel in case of failure of the pressurized gas supply in the armature space is (aging). When approaching the armature space 9 with compressed gas is the check valve 30 closed here, otherwise open.

1b illustrates another embodiment of the injector 1 , which in contrast to the embodiment according to 1a a particularly pressure balanced, solenoid actuator operated valve or pilot valve 2 has, the valve member 12 in the closed position no axial in the opening direction 8th acting compressive forces, ie with adjacent high pressure at the injector 1 ,

The injector 1 here has a chamber 38 on which the nozzle-near anchor rod end 10a or a section adjacent to it. About the leadership 11 over which the anchor rod 10 axially movable in the chamber 38 is conducted, the chamber communicates 38 with the anchor room 9 or the magnetic space 6 , ie via an annular gap between the wall of the guide 11 and the anchor rod 10 ,

The anchor rod 10 in this case forms a valve member 12 in the form of an annular sealing or biting edge at the nozzle near end 10a , Over the valve member 12 or the valve 2 is a mouth section of the pipe section 20b the leakage discharge line 20 lockable, which in the chamber 38 empties. In the chamber 38 is still the line section 20a with the chamber 38 (and at the other end with the control room 18 ) communicating, wherein the line section 20a radially into the chamber 38 empties.

With applied high pressure and closed valve 2 becomes the chamber 38 over the line 20a pressurized via high pressurized fuel, wherein the valve member 12 the mouth of the pipe 20b obstructed, in particular experiences no axially acting load by high-pressure fuel. Opens the valve 2 , the anchor rod moves 10 or the valve member 12 away from the mouth opening or the valve seat surface, ie in the axial direction, and the mouth opening of the line section 20b will be released. This allows the chamber 38 over the line section 20b relieved of pressure, ie associated with a discharge of the control room 18 ,

To the anchor room 9 to be able to drain, ie the hydraulic resistance, the anchor plate 7 during a movement in the anchor room 9 otherwise could learn to lower, especially to eliminate, points the injector 1 as in the embodiment described above 1a a compressed gas line or a compressed gas channel 26 on which of an inlet 27 at the injector 1 to the magnet room 6 is guided. About the compressed gas channel 26 can the anchor space 9 - via the communicating with this magnetic space 6 - With compressed gas, in particular compressed air, flowed through, in particular also flows through, so that leakage from the armature space 9 both displaced as can also be prevented from entering it. In the compressed gas channel 26 Here again is a check valve 28 upstream of the magnetic space 6 arranged, which can prevent fuel or leakage enters the compressed gas supply system. The check valve is closed when no pressurized gas to the armature space 9 is supplied.

The injector 1 according to 1b points to the discharge of leakage from the armature space 9 , which by means of the anchor space 9 introduced compressed gas is displaced, an additional leakage discharge line 29 next to the leak discharge line 20 respectively. 20b on which with the anchor space 9 on the one hand (about the leadership 11 ) and with the leakage discharge line 20 or their section 20b on the other hand communicates. The additional leakage line 29 allows, even during the closed state of the valve 2 Leakage from the armature room 9 be able to dissipate by means of compressed gas, ie in the case in which the mouth opening of the line section 20b at the chamber 38 is locked. About the leak discharge line (s) 20 (and 29 ), the compressed gas can be advantageously removed in this case. The leakage line 29 opens at the armature end of the anchor guide 11 from this, ie such that a lubrication of the anchor rod 10 is guaranteed, or alternatively z. B. at a valve side or near the nozzle end of the armature space 9 from the same.

2 shows a device 32 , in particular for a motor vehicle, the device 32 an injector 1 and a pressurized gas source 33 has, in particular a compressed air source. The compressed air source 33 is with the inlet end 27 of the compressed gas channel 26 connected, ie via a pressurized gas supply line 34 ,

To compressed gas as needed to the injector 1 to supply, instructs the device 32 furthermore a control device 35 as well as one in the supply line 34 arranged, via the control device 35 controllable valve 36 on. Depending on the control of the valve 36 can the decor 32 thus different pressure gas pressure levels in the armature space 9 of the injector 1 to adjust. The control device 35 may be a control unit of a fuel injection device, wherein the device 32 preferably such a fuel injection system forms (not shown), in particular for a motor vehicle.

The device 32 is further formed by means of the compressed gas flow or flow through the armature space 9 both a penetration of fuel into the armature space 9 to prevent, ie by means of continuously introduced compressed gas (sealing air), in particular during a first operating state of the injector 1 , as well as to fuel from the anchor space 9 to displace, in particular during at least a second operating state of the injector.

This will be described below in conjunction with the embodiment of the injector 1 according to 1b explained by an example.

In a first operating state, corresponding to z. B. a resting state (ie the injector 1 does not inject) becomes the anchor rod guide 11 at the valve end z. B. with injection system pressure or high pressure (about 2500 bar) applied, resulting in a permanent leak. So that the fuel is not in the anchor space 9 penetrates, sealing air (compressed gas) is on the armature space 9 given. The air pressure or the pressure gas pressure level is set for this purpose on average always higher than the leakage pressure.

For a second operating state corresponding to z. B. an injection process opens the pilot valve 2 for a short duration of z. B. max. 5 ms. During this time, the pressure at the valve end of the anchor rod guide decreases 11 Although from, the pressure in the leakage system of the injector 1 However, it briefly increases up to about 10 bar, causing fuel to enter the armature space 9 comes, ie via the leakage discharge line 29 , Since this pressure increase is comparatively short compared to the rest periods during combustion and the charge cycle, the fuel input into the armature space 9 very low. The air pressure or the compressed gas pressure level in the armature space 9 is therefore such that the briefly introduced fuel in the break until the next injection event again completely displaced and also as little air is entered into the leakage system, ie via the leakage discharge line 29 ,

For the case described, in which the injector 1 z. B. when the engine is running, ie B. in a motor vehicle, is operated by the intermittent intrusion and displacement of the fuel from the armature space 9 At almost balanced mean pressures advantageous also the lubrication of the anchor rod 11 ensured.

When stopping the engine, ie falling pressure, the armature space 9 and the magnet room 6 filled. Starting the engine can still be done advantageously without delay in the context of the present invention. The still fuel filled anchor space 9 can be emptied via the injected compressed gas within a few seconds. For rapid emptying, a pressure gas pressure level can be increased, ie via the controller 35 (or regulation). Alternatively it can be provided, the armature space 9 initially to pressurize with an elevated pressure gas pressure level until emptying has taken place and then to start the engine.

With the invention, a shortening of the pilot valve opening duration by approximately 50% and a shortening of the closing duration, depending on the spring design, of approximately 40% can advantageously be achieved during engine operation. The invention can be used with different valves 2 are executed, in particular with a 3/2-way valve (not shown).

LIST OF REFERENCE NUMBERS

1

injector

2

Valve

3

actuator

4

magnet set

5

injector

6

magnetic space

7

anchor

8th

arrow

9

armature space

10

anchor rod

11

Anchor rod guide

12

valve member

13

valve seat

14

compression spring

15

nozzle needle

16

nozzle body

17

nozzle spring

18

control room

19

shell

20

Leakage discharge pipe

21

needle seat

22

High-pressure line

23

Storage

24

Flow regulator

25

branch

26

Compressed gas channel

27

inlet

28

check valve

29

Leakage discharge pipe

30

check valve

31

leakage line

32

Facility

33

Compressed gas source

34

Pressure gas supply line

35

control device

36

Valve

37

throttle

38

chamber

Claims (12)

Injector ( 1 ) with a solenoid actuator operated pilot valve ( 2 ), the anchor ( 7 ) of the actuator ( 3 ) in an anchor space ( 9 ) at the injector ( 1 ) for displacing the valve member ( 12 ) of the pilot valve ( 2 ) is movable, wherein the injector ( 1 ) for introducing pressurized gas into the armature space ( 9 ) is designed to act against leakage, which via a leakage path in the armature space ( 9 ), the injector ( 1 ) at least one leakage discharge line ( 20 . 29 ), via which the pressurized gas and / or by means of the compressed gas displaced leakage from the armature space ( 9 ) is dissipatable. Injector ( 1 ) according to claim 1, characterized in that the injector ( 1 ) at least one channel ( 26 ) for introducing pressurized gas into the armature space ( 9 ) having. Injector ( 1 ) according to one of the preceding claims, characterized in that the injector ( 1 ) is formed, compressed gas via a magnetic space ( 6 ) in the anchor space ( 9 ). Injector ( 1 ) according to claim 2 with 3, characterized in that the channel ( 26 ) for introducing pressurized gas into the magnet space ( 6 ) opens. Injector ( 1 ) according to one of the preceding claims, characterized in that the armature ( 7 ) as an anchor plate of a magnetic actuator ( 3 ) is formed. Facility ( 32 ), characterized in that the device ( 32 ) at least one injector ( 1 ) according to one of the preceding claims, wherein the device ( 32 ) to the pneumatic flow of the armature space ( 9 ) of the at least one injector ( 1 ) is designed to act against leakage. Facility ( 32 ) according to claim 6, characterized in that the device ( 32 ) at least one compressed gas source ( 33 ), over which a respective armature space ( 9 ) is pressurized with compressed gas. Facility ( 32 ) according to claim 7, characterized in that the at least one compressed gas source ( 33 ) by a control or regulating device ( 35 ) of the institution ( 32 ) is activated. Facility ( 32 ) according to one of claims 6 to 8, characterized in that the device ( 32 ) for setting variable pressure gas pressure levels in a respective armature space ( 9 ) is trained. Facility ( 32 ) according to one of claims 6 to 9, characterized in that the device ( 32 ), leakage at the entrance into a respective armature space ( 9 ) and / or formed leakage into the armature space ( 9 ) introduced compressed gas from the respective armature space ( 9 ) to displace. Facility ( 32 ) according to one of claims 6 to 10, characterized in that the device ( 32 ) forms a fuel injection system. Motor vehicle, characterized in that the motor vehicle is an onboard compressed gas source ( 33 ), which with at least one injector ( 1 ) according to one of claims 1 to 5 for the pneumatic flow of an armature space ( 9 ) of the same cooperates.

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