DE102010012471A1 - Positioning device e.g. double positioning device, for three speed stroke-variable valve train of combustion engine, has current signal lines passed through one of positioning pins whose outer ends are connected with plug pins - Google Patents

Abstract

The device (112) has positioning pins (110,111) that are moved between a resting position at which the pins are brought into a housing (13) and a working position at which the pins are driven out from the housing. Outer ends (114) of the pins adjust a cam position, such that the device provides an electrical output to detect the cam position. Electrically isolated current signal lines for an output voltage signal are passed through one of the positioning pins, and electrically insulated from the housing. Outer ends of the pins are connected with plug pins (P2, P5) arranged at the housing.

Description

Field of the invention

The invention relates to an adjusting device for a cam-side adjustable valve train of an internal combustion engine with variably actuated gas exchange valves. The adjusting device comprises a housing and one or more adjusting pins, which are movably mounted in the housing between a retracted into the housing rest position and a working position extended from the housing and whose extended from the housing, outer pin ends are used to adjust the cam position, and provides an electrical Output signal ready for detecting the cam position.

Background of the invention

In the context of the present invention, valve drives that can be adjusted on the cam are understood to mean those valve drives which generate the stroke variability on the gas exchange valve by means of axially displaceable cam pieces. These are provided with cam groups whose different cam lobes - depending on the axial cam position - are selectively engaged with a rigid cam follower. For axial adjustment of the cam piece is usually a stationary supported in the internal combustion engine actuator of the type mentioned with an actuating pin (or more) provided which couples in the extended working position in a spiralnutförmige Axialkulisse on the rotating cam piece and a displacement of the cam piece to the Axialhub Spiral groove enforces. The relevant operating principle goes in detail from the EP 0 798 451 B1 out.

In order to monitor the adjustment of the cam piece from a first to a second cam position, it is already proposed in the prior art, the actuator not only as an actuator in the form of the coupling into the axial slide pin but also as a detector for the state of motion of the actuating pin and, of it derived form for the position of the cam piece. In the considered as generic publications DE 10 2006 035 225 A1 and DE 10 2008 024 086 A1 In each case, an actuating device is disclosed whose operating principle is based on the interaction of a stationary magnet coil and a permanent magnet fixed to the actuating pin. The spiral groove-shaped Axialkulisse has a radially rising end portion, which decouples the adjusting pin with almost or completely shifted cam piece from the Axialkulisse, so that the permanent magnet is driven back in its adhering to the magnetic coil initial position. The output signal provided by the adjusting device in the form of a voltage induced in the magnetic coil and the course of the induced voltage evaluated in an evaluation unit provide information about the success of the displacement of the cam piece.

Object of the invention

The present invention has for its object to design an adjusting device of the type mentioned in terms of the fact that the cam position is already detectable before an adjustment of the cam piece.

Summary of the invention

The solution of this problem arises from the characterizing features of claim 1, while advantageous developments and refinements of the invention are the dependent claims can be removed. Accordingly, the actuator should have at least one electrically isolated current signal line for the output signal, wherein the current signal line passes over one of the adjusting pins, which is electrically isolated from the housing, and connects the outer pin end of this actuating pin with a housing disposed on the terminal contact.

A so configured adjusting device is suitable for cooperation with a cam-side adjustable valve train, which comprises a detection device in an electrical circuit which extends over the cam piece and the adjusting device. In this case, the circumference of the cam piece in the region of the Axialkulisse is provided with means for generating a variable with the rotational position of the cam piece current signal in the circuit, and forming with the rotation of the cam piece current waveforms are different from each other in each of the axial positions of the cam piece. The detection device connected to the connection contact of the actuating device is set up to evaluate the current signals and to associate with each of the current signal curves the associated instantaneous axial position of the cam piece, without requiring a prior adjustment of the cam piece. The detection device can arranged outside the adjusting device and be part of the engine control unit of the internal combustion engine, for example. But it can also be an integral part of the adjusting device, so that abut the already evaluated information about the current cam position at the connection contact.

The term current signal refers not only to the current, but also includes related variables such as voltage or ohmic resistance in the circuit.

Unlike in the cited prior art, it is therefore not necessary according to the invention to perform a displacement of the cam piece in order to determine only its axial position. Rather, this determination and transmission to the engine control unit already during the start of the internal combustion engine with the first revolution of the camshaft and without any necessary back shifting of the cam piece done in its original axial position, which is provided for the change of charge of the internal combustion engine at its current operating point. In addition, a displacement of the cam piece, which according to the known prior art merely serves to determine its (original) axial position, could lead to destruction of the valve drive as a result of colliding gas exchange valves, if in the displaced axial position no clearance between the frequently V-shaped relative to each other arranged inlet and outlet valves consists.

In a further development of the invention, the adjusting pin over which the Strömsignalleitung runs to be stored in a thin-walled, retracted in the housing socket whose outer jacket is covered with an electrical insulator. This is expediently a ceramic sprayed layer on the socket.

• • den Stellstiften jeweils zugeordnete Federmittel, die die Stellstifte in die Ausfahrrichtung kraftbeaufschlagen,
• • den Stellstiften jeweils zugeordnete Sperrstifte, die die Stellstifte mittels Rastierungen in der Ruheposition halten und in Verfahrrichtung der Stellstifte relativ zu diesen verlagerbar sind,
• • den Sperrstiften jeweils zugeordnete weitere Federmittel, die die Sperrstifte in die Ausfahrrichtung kraftbeaufschlagen,
• • und den Sperrstiften jeweils zugeordnete Magnetspulen, die zum Lösen der Rastierungen die Sperrstifte mittels elektromagnetischer Kraftbeaufschlagung in die Einfahrrichtung verlagern.

In specifying the invention, the adjusting device should comprise the following:

• Spring means respectively assigned to the adjusting pins, which force the adjusting pins in the direction of extension,
• • the adjusting pins respectively assigned locking pins that hold the adjusting pins by means of detents in the rest position and are displaceable in the direction of travel of the adjusting pins relative to these,
• • the locking pins respectively associated further spring means which force the locking pins in the extension direction,
• • and the locking pins respectively associated magnetic coils that relocate the locking pins by means of electromagnetic force in the retraction to release the detents.

In this case, the current signal line extends over the coil core of one of the magnetic coils, which coil core is electrically insulated from the yoke plate of a magnetic coil. Preferably, the coil core of this magnetic coil is coated in the region of the yoke plate with an electrical insulator, and expediently, this insulator is also a ceramic sprayed layer on the coil core. Alternative insulators may be selected from the variety of known insulating materials (eg, insulating paints) and assemblies (eg, coatings or individual parts). It is also conceivable to dispense with the electrically insulating coatings or separate insulator components and to carry out, for example, the housing in the storage area of the adjusting pins in plastic.

In addition, it is provided that the adjusting device comprises at least two actuating pins mounted in a common housing and current signal lines extending over at least two of the adjusting pins. In this arrangement, hereinafter referred to as parallel signal evaluation, the current signals of several circuits are evaluated simultaneously and the corresponding axial position of the cam piece is assigned.

Alternatively, the adjusting device can also be designed so that it comprises a plurality of adjusting pins, but only a current signal line. In this arrangement, referred to as serial signal evaluation arrangement, the successive current signals of the single circuit are evaluated on the cam piece and associated with the corresponding axial position of the cam piece.

Brief description of the drawings

Further features of the invention will become apparent from the following description and from the drawings, in which an embodiment of the invention is shown. In this case, the first digit of the respective reference number refers to the corresponding figure, or the same or functionally identical features or components are provided with the same reference numerals. Show it:

1 an adjusting device according to the invention in longitudinal section;

1a the detail X out 1 ;

1b the detail Y out 1 ;

1c the adjusting device according to 1 with schematically drawn current signal line;

1d the pin assignment of the adjusting device according to 1 ;

1e the adjusting device according to 1 in perspective view;

2 a three-stage variable-stroke valve drive in conjunction with the circuit diagram of a detection device with parallel signal evaluation;

2a the section II according to 2 ;

2 B Section II-II according to 2 ;

3 a known valve train with a double-actuator and a Axialkulisse with two intersecting tracks and

4 a known valve train with two single-setting devices and two Axialkulissen each with a sliding track.

Detailed description of the drawings

The invention is based on 4 explains, in which the mechanical operating principle of a known variable-stroke valve drive of an internal combustion engine with movable cam pieces is shown. The valve train 401 includes a camshaft 402 with an externally toothed carrier shaft 403 and by means of a corresponding inner longitudinal toothing thereon rotationally fixed and in each case between two axial positions longitudinally displaceably arranged cam pieces 404 of which only one is shown. That in a camshaft bearing 405 the engine centrally mounted cam piece 404 has two groups of cams immediately adjacent cams 406a and 406b with different surveys, the operating point-dependent actuation of gas exchange valves 7 by means of drag levers 8th serve. The for selective activation of the respective cam 406a or 406b required displacement of the cam piece 404 on the carrier shaft 403 takes place via two at the ends of the cam piece 404 running axial scenes 409 in the form of spiral groove-shaped moving tracks 409a and 409b , which differ according to the direction of displacement in their orientation and in, depending on the instantaneous axial position of the cam piece 404 , respectively the outer pin end of pins 410 . 411 stationary in the internal combustion engine recorded electromagnetic actuators 412 is radially coupled to the cam piece 404 to move.

The moving tracks 409a . 409b extend not only in the axial but also in the radial direction such that the adjusting pins 410 . 411 Towards the end of the shifting process by radially rising ejection ramps from the moving tracks 409a . 409b decoupled and in their non-engaging rest position in the adjusting devices 412 to be brought.

In the likewise known valve train 301 according to 3 has the cam piece 304 two groups of cams, each with three immediately adjacent cams 306a . 306b and 306c on. For shifting the cam piece 304 between its three axial positions is merely an axial backdrop 309 with two intersecting moving tracks 309a and 309b and only one actuator 312 with two pins 310 and 311 provided, the outer pin ends depending on the direction of displacement of the cam piece 304 alternately or successively in the axial slide 309 inject. The drag levers according to 4 are here by their cam rollers 8th symbolizes.

An embodiment of an adjusting device according to the invention 112 is in 1 disclosed. The adjusting device 112 includes two in a common housing 13 recorded and spaced around a cam width mounted pins 110 . 111 and is intended, according to a cam piece with a two intersecting sliding tracks having Axialkulisse 3 to move. The adjusting pins move to adjust the cam piece 110 . 111 between one in the housing 13 retracted rest position (as shown) and one out of the housing 13 extended working position back and forth, taking out the case 13 extended and coupled into the Axialkulisse outer pin ends 114 that's it support supporting axial slide to a cam width. The inner ends of the pencil 15 are as spring support for spring means in the form of helical compression springs 116 formed the stamper 110 . 111 in the extension direction kraftbeaufschlagen.

The housing 13 is from an upper housing part 17 and a housing lower part fixed therein 18 composed. In the case upper part 17 it is a Blechumformteil, while the lower housing part 18 made of steel material. As well as from the perspective view of the actuator 112 in 1e shows, is the upper housing part 17 with a mounting flange 19 and a sealing ring 20 for the sealed fastening of the adjusting device 112 provided in the cylinder head of an internal combustion engine. For longitudinally movable mounting of the adjusting pins 110 . 111 serve in the housing base 18 retracted sockets 21 made of thin-walled steel, whose outer circumferential surfaces for the purpose of electrical insulation of the hardened steel pins 110 . 111 opposite the lower housing part 18 with a ceramic sprayed layer 22 are provided. This is in 1b illustrated with the detail Y.

In the housing inner end portion of the sockets 21 are aluminum guides 23 with several circumferentially distributed overflow channels 24 attached. The aluminum guides 23 serve for longitudinal guidance and as axial stop of locking pins 25 holding the hollow cylindrical pins 110 . 111 hold by means of detents in the rest position and in the direction of travel of the adjusting pins 110 . 111 relative to these are relocatable. The locking pins 25 each have a circular frustoconical first end portion, which serves as the first support surface 26 for three trained as balls detent body 127 serves. The balls 127 are in evenly over the circumference of the adjusting pins 110 . 111 distributed transverse bores arranged movably and are supported on a circular cone-shaped second support surface 28 the socket 21 from.

The second end portion of each locking pin 25 is provided with a hollow cylindrical recess into which a pressure piece 29 made of aluminum and also as a helical compression spring 30 trained further spring means that the locking pin 25 subjected to force in the extension direction, are used longitudinally movable.

The pressure pieces 29 rest on the coil cores 31 two of the locking pins 25 assigned and in the upper housing part 17 plastic molded pickup magnetic coils 32 from which are selectively energized to release the detents and respectively the associated, at the second end portion in diameter expanded locking pin 25 electromagnetically force and against the force of the helical compression spring 30 shift in the retraction direction.

Releasing the detent causes the balls 127 no longer in its latched position from the first support surface 26 at the locking pin 25 be supported, but can move in a radially inward direction, while the by the helical compression spring 116 force-loaded adjusting pin 110 or 111 together with the balls 127 extends into its working position. The energization of the magnetic coil 32 is turned off at this time, so that the locking pin 25 until the stop on the aluminum guide 23 also shifted in the extension direction.

The required after the displacement of the cam piece reset the actuator pin 110 or 111 in its retracted rest position is known to take place by the moving tracks of the Axialkulisse, which is a radially elevating and the adjusting pin 110 or 111 have back driving ejection ramp. Shortly before reaching the resting position the balls hit 127 on the first end portion of the locking pin 25 and lift it in the direction of the solenoid 32 at. Finally, the now released in radially outward direction balls 127 back in their latching position to the second support surface 28 relocated. As explained later, it is important that the adjusting pins 110 . 111 also in their retracted rest position and locking locked further in the retracting direction are displaced. This additional Einfahrweg done by the stalks 110 . 111 against the force of the helical compression spring 116 and on the part of the locking pins against the force of the helical compression spring 30 ,

To power the solenoid coils 32 serves a 6-pin electrical connector 33 made of plastic, whose pin assignment 1d evident. The connector pins P2 and P5 are terminal contacts, each with the coil cores 31 are electrically connected. The locking pins 25 opposite sides of the coil cores 31 are by means of an electrical insulator in the yoke plate 34 of the magnetic coils 32 edged. As it is from the detail X according to 1a As can be seen, the insulator is also a ceramic sprayed layer 35 that the coil cores 31 at one of the yoke plate 34 covered diameter step covers.

As it is in 1c is schematically illustrated, by the aforementioned isolation measures, two electrically isolated current signal lines in the form of current paths shown in dashed lines 136 and 137 created, each via the control pin 110 . 111 run and the outer ends of the pencil 114 via balls 127 , Locking pin 25 , Pressure piece 29 and spool core 31 and / or via jack 21 , Aluminum guide 23 , Locking pin 25 , Pressure piece 29 and spool core 31 connect to the connection contacts P2 or P5.

The function of the current signal lines will be described below with reference to 2 explained. The valve train 201 includes a detection device that allows, even before a displacement operation of the cam piece 204 , For example, immediately after the start of the internal combustion engine to determine its instantaneous cam position. The detection device is by the adjusting device 212 with the pins 210 and 211 and an evaluating logic unit 38 is formed as part of the engine control unit and is in two electrical circuits 39 and 40 connected, starting from a voltage source (not shown, mass of an accumulator of the internal combustion engine) via the camshaft bearing 205 , the carrier wave 203 , the cam piece 204 in the actuator 212 formed current signal lines 236 and 237 and the logic unit 38 back to the voltage source (phase of the accumulator) runs.

The axial slide shown schematically 209 corresponds to the in 3 illustrated axial scenery 309 with the two intersecting railways 309a and 309b , In the illustrated instantaneous cam position, the middle cam operates 206b the cam roller 8th of the finger lever, and accordingly runs in each retracted rest position of the adjusting pin 210 above the left portion of the axial slide 209 while the adjusting pin 211 above the right section of the axial slide 209 runs. As can be seen from the sectional views through the left and right section of the axial slide 209 in the 2a and 2 B becomes clear, is the circumference of the cam piece 204 in the area of the axial backdrop 209 with local (and clearly exaggerated) surveys 41 . 42 and 43 Mistake. These each generate one with the rotational position of the cam piece 204 changing voltage signal in the current signal lines 236 and 237 by only the surveys 41 . 42 . 43 the outer ends of the pencil 214 the adjusting pins 210 respectively. 211 contact and so the circuits 39 and 40 Temporarily close while the adjusting pins 210 . 211 on the peripheral area outside the elevations 41 . 42 . 43 around one the circuits 39 . 40 interrupting air gap 44 from the cam piece 204 run at a distance. The when driving over the surveys 41 . 42 . 43 required and previously explained compliance of the adjusting pins 210 . 211 in the direction of retraction is by the springs shown schematically 216 and ratchet body 227 symbolizes.

The changing voltage signals are applied to the connector pins P2 and P5 as output signals and are in parallel signal sequence of the logic unit 38 supplied, which evaluates the signals by means of symbolically represented logic links and the instantaneous cam position of the cam piece 204 assigns. This is done according to the following scheme, with signal A from the survey 41 and signal B from the two surveys 42 and 43 results. The state that the logic unit 38 no current signal due, for example, to an interruption in the circuits 39 . 40 receives is interpreted as an error. Signal P2 Signal P5 Cam Survey No. no signal no signal System error or defect no signal Signal A 206a Signal A Signal B 206b Signal B no signal 206c

Not shown are the right cam position, in which the left cam 206a the cam roller 8th operated, and the left cam position, in which the right cam 206c the cam roller 8th actuated.

In the right cam position is the adjusting pin 210 permanently out of engagement with the axial slide 209 and according to the circuit 39 permanently open, so that no output signal is present at the connection contact P2. The adjusting pin 211 however, the survey takes effect 41 so that the output signal A is present at the connection contact P5. This state becomes the instantaneous cam lobe according to the scheme above 206a assigned.

In the left cam position is the adjusting pin 210 permanently out of engagement with the axial slide 209 and according to the circuit 40 permanently open, so that no output signal is present at connection contact P5. The adjusting pin 210 however, the surveys intervene 42 and 43 off, so that at the connection contact P2 the Output signal B is present. This state becomes the instantaneous cam lobe according to the scheme above 206c assigned.

LIST OF REFERENCE NUMBERS

1

valve train

2

camshaft

3

carrier wave

4

cam piece

5

Camshaft bearing

6

cam

7

Gas exchange valve

8th

Drag lever / cam roller

9

Axial slotted / sliding track

10

setting rod

11

setting rod

12

locking device

13

casing

14

outer pin end of the pin

15

inner pin end of the pin

16

Spring means / helical compression spring

17

Housing top

18

Housing bottom

19

mounting flange

20

seal

21

Rifle

22

ceramic spray coating / electrical insulator

23

aluminum guide

24

overflow

25

locking pin

26

first support surface

27

Ball / detent body

28

second support surface

29

Pressure piece

30

Helical compression spring / further spring means

31

Plunger

32

solenoid

33

plug

34

yoke plate

35

ceramic spray coating / electrical insulator

36

Current signal line

37

Current signal line

38

logic unit

39

circuit

40

circuit

41

survey

42

survey

43

survey

44

air gap

P1 to P5

Connector pin / terminal contact

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

• EP 0798451 B1 [0002]
• DE 102006035225 A1 [0003]
• DE 102008024086 A1 [0003]

Claims (7)

Adjusting device ( 12 ) for a cam-side adjustable valve train ( 1 ) an internal combustion engine with variably operated gas exchange valves ( 7 ), comprising a housing ( 13 ) and one or more adjusting pins ( 10 . 11 ), which between one in the housing ( 13 ) retracted rest position and one from the housing ( 13 ) extended working position movable in the housing ( 13 ) are stored and their from the housing ( 13 ) extended outer pin ends ( 14 ) serve to adjust the cam position, wherein the adjusting device ( 12 ) provides an electrical output signal for detecting the cam position, characterized in that the actuating device ( 12 ) at least one electrically isolated current signal line ( 36 . 37 ) for the output signal, wherein the current signal line ( 36 . 37 ) via one of the adjusting pins ( 10 . 11 ) extending from the housing ( 13 ) is electrically isolated, and the outer pin end ( 14 ) of this adjusting pin ( 10 . 11 ) with one on the housing ( 13 ) arranged connecting contact (P2, P5) connects. Adjusting device according to claim 1, characterized in that the one adjusting pin ( 10 . 11 ) in a thin-walled, in the housing ( 13 ) retracted socket ( 21 ) whose outer jacket is provided with an electrical insulator ( 22 ) is coated. Adjusting device according to claim 2, characterized in that the electrical insulator ( 22 ) a ceramic sprayed layer on the socket ( 21 ). Adjusting device according to claim 1, characterized in that it further comprises: • the adjusting pins ( 10 . 11 ) each associated spring means ( 16 ), which the adjusting pins ( 10 . 11 ) in the extension direction, • the adjusting pins ( 10 . 11 ) associated locking pins ( 25 ), which the adjusting pins ( 10 . 11 ) by means of detents ( 27 ) in the rest position and in the direction of travel of the adjusting pins ( 10 . 11 ) are displaceable relative to these, • the locking pins ( 25 ) associated with each other spring means ( 30 ), which the locking pins ( 25 ) in the extension direction, • the locking pins ( 25 ) associated with each solenoid coils ( 32 ), which are used to release the detents ( 27 ) the locking pins ( 25 ) by means of electromagnetic force in the retraction direction, wherein the current signal line ( 36 . 37 ) over the spool core ( 31 ) one of the magnetic coils ( 32 ), which spool core ( 31 ) of the yoke plate ( 34 ) of a magnetic coil ( 32 ) is electrically isolated. Adjusting device according to claim 4, characterized in that the coil core ( 31 ) of a magnetic coil ( 32 ) in the region of the yoke plate ( 34 ) with an electrical insulator ( 35 ) is coated. Adjusting device according to claim 5, characterized in that the electrical insulator ( 35 ) a ceramic sprayed layer on the spool core ( 31 ). Adjusting device according to claim 1, characterized in that the adjusting device ( 12 ) at least two in a common housing ( 13 ) mounted parking pins ( 10 . 11 ) and at least two of the adjusting pins ( 10 . 11 ) current signal lines ( 36 . 36 ).

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