DE102009030375A1 - Electromagnetic control device has housing and actuator pins, which are displaced between retracted rest position in housing and working position extended from housing independent of each other - Google Patents

Abstract

The electromagnetic control device (1) has a housing (2) and actuator pins (3,3.1,3.2,3.3,3.4), which are displaced between a retracted rest position in the housing and a working position extended from the housing independent of each other. The actuator pins are supported in the housing adjacent to each other, and are impinged with force from spring unit in extension direction. Two independently energizable electromagnets (19.1,19.2) are provided with reversible direction of the magnetic field and three actuator pins.

Description

Field of the invention

The The invention relates to an electromagnetic actuator with a housing and actuator pins that between a in the housing retracted rest position and one of the Housing extended working position independently moved from each other and stored side by side in the housing and are urged by spring means in the extension direction, and the actuator pins respectively associated locking pins, the hold the actuator pins by means of detents in the rest position and in the direction of movement of the actuator pins relative to these displaced are. In this case, the locking pins are remote from the actuator pins End sections with in the direction of travel two-pole magnetized permanent magnet provided and are electromagnetically powered to release the detents shifted in the retraction direction.

Background of the invention

Such a control device is particularly suitable for adjusting hubvariabler valve trains of internal combustion engines whose principle Funkti onsweise, for example, from DE 10 2004 021 376 A1 evident. The stroke variability of this valve train is based on a cam piece with two cams arranged directly adjacent thereto, whose different opening characteristics are selectively transmitted to a gas exchange valve by means of a conventionally rigid cam follower. For operating point-dependent adjustment of these opening courses, the cam piece is non-rotatably, but arranged longitudinally displaceable on a support shaft and has two spiral and oppositely extending sliding grooves, in which the end portions of the actuator pins of two actuators (each with an actuator pin) are alternately coupled. While the axial course of the sliding groove engaged with the associated actuator pin causes the cam piece to self-steer and camshaft angle shift from one to the other cam position, the radial extent of each slide groove is designed to become progressively flatter toward the end of the shifting operation is moved and the currently engaged actuator pin from its working position back to the rest position.

In case of in the DE 196 11 641 C1 proposed valve train with three adjacent cams and two arranged at a small distance actuator pins, it seems appropriate to integrate the actuator pins in a common housing.

An actuator with a group of independently movable actuator pins, which are mounted in a common housing and cooperate with electromagnetically kraftbeaufschlagten locking pins in the above manner, goes out of the DE 10 2006 051 809 A1 out. The electromagnetic force is applied to the locking pins by means of magnetic anchors attached thereto, each of which forms a Elektrohubmagneten associated with magnetic coils. In the case of two actuator pins thus two such Elektrohubmagneten are required at a correspondingly high cost of manufacture and installation of the actuator.

This consideration applies equally to an actuator according to the DE 10 2007 024 598 A1 to, if a group of actuator pins in a common housing to be summarized.

In the WO 03/021612 A1 is proposed an actuating device whose operation is based on the interaction of an electromagnet with a permanent magnet attached to the actuator pin. Due to its magnetic attraction of the spring-loaded in the extension direction actuator pin adheres to the de-energized electromagnet. To release the actuator pin from this rest position, only a pulse-shaped current loading of the electromagnet is required to overcome the magnetic attraction of the permanent magnet, the Aktuatorstift not only by the force of the spring means but also by the force of a magnetic repulsion effect between the permanent magnet and the energized electromagnet in the direction the working position is accelerated.

A constructive development of this functional principle is in the DE 20 2008 008 142 U1 disclosed. The actuator pin is held there only by the magnetic attraction force on a permanent magnet, so that a mutually eccentric arrangement of actuator pins and permanent magnets / electromagnets a compact design of the actuator with two or three actuator pins in a common housing is made possible.

apart from the common housing require all mentioned actuators with several actuator pins a considerable manufacturing and assembly costs, since cost synergy effects mainly only resulting from the common housing.

An electromagnetic actuator of the type mentioned is from the unpublished DE 10 2009 010 949 A1 the applicant. This actuator has two actuator pins, which in conjunction with a bidirectional we kenden Axialkulisse with two intersecting sliding grooves according to the DE 10 2007 051 739 A1 allow a shift of the cam piece in a maximum of three stages.

Object of the invention

Of the The present invention is therefore based on the object, an adjusting device of the aforementioned type so that the adjusting device for use in four- or higher-level lifting variables Valve drives with displaceable cam pieces are suitable and is designed as compact as possible.

Summary of the invention

The Solution to this problem arises from the features of Claim 1, while advantageous developments and refinements the dependent claims are removable. Accordingly, the task becomes achieved in that the adjusting device at least two independently energized electromagnets with each reversible direction of the magnetic field and at least three Having actuator pins. The electromagnets should each force two directly adjacent permanent magnets whose Polungen are aligned opposite to each other.

Opposed to the quoted DE 10 2006 051 809 A1 The adjusting device according to the invention is not merely a combination of three or more identical individual actuators in a common housing. In view of a small number of components and in favor of a compact design, it is rather provided that each of the electromagnets are each associated with two actuator pins, so that the number of electromagnets is always smaller than the number of actuator pins. In this case, at least three actuator pins are provided, which according to the DE 10 2007 051 739 A1 a four-stage stroke variability allow a valve train with sliding cam pieces.

The opposite orientation of the magnetic poles of two directly adjacent Permanent magnet leads to the fact that when energized the respectively assigned Electromagnets the same from this magnetic field generated the first Tightens permanent magnet and repels the second permanent magnet. In connection with the direction reversal of the magnetic field - this is the electromagnet for reversing the current direction electrically umzupolen - is so only one solenoid required to connect two actuator pins to drive alternatively. This shifts with the first Permanent magnet connected locking pin in the direction of the electromagnet, d. H. in the retraction direction of the associated first actuator pin, which is now released detent and optionally by the force of another spring means in its working position relocated. In contrast, remain with the second Permanent magnet connected locking pin and the associated second Aktuatorstift and the third and possibly further Actuator pins in their rest position.

at opposite poled energization of the electromagnet reverses the effect of the magnetic field, so that now the second permanent magnet is attracted while the first permanent magnet repelled becomes. The starting point for this is again the state that the actuator pins by means of the detents in their rest positions are held. In an analogous way, now displaces the second Aktuatorstift in its working position, while the rest Actuator pins remain in their rest position.

In Development of the invention, the electromagnets by a Housing wall of magnetically conductive material from each other be separated. The magnetically conductive housing wall between The magnetic coils of the electromagnets generates a magnetic Short circuit and prevents the magnetic field from being energized Magnetic coil to the adjacent, non-energized magnetic coil propagates and generates a voltage as a result of the field induced there. These Tension would not just (in an undesirable way) retroactively on the control unit of the adjusting device but also lead to the risk of mishandling, by the permanent magnet of a currently not operated Locking pin is tightened and the associated actuator pin inadmissible moves into its working position. To avoid this, so each solenoid has its own closed coil jacket made of magnetically conductive material. Its high conductivity causes the magnetic Field lines not the way across the adjacent solenoid, but take through the housing wall.

According to one later explained first embodiment The invention can use two electromagnets and four actuator pins be provided. In a second embodiment the adjusting device comprises two electromagnets and three actuator pins, wherein the middle permanent magnet of both electromagnets force becomes.

• – eine im Aktuatorstift verlaufende Längsbohrung zur Aufnahme des Sperrstifts und eine oder mehrere die Längsbohrung schneidende Querbohrungen,
• – eine am Sperrstift ausgebildete erste Stützfläche und eine im Gehäuse ausgebildete zweite Stützfläche, wobei zumindest eine der Stützflächen gegenüber der Verfahrrichtung geneigt verläuft,
• – und einen oder mehrere Rastkörper, die in den Querbohrungen beweglich angeordnet und in der Ruheposition zwischen den Stützflächen eingespannt sind.

In a preferred embodiment, the detents should each be formed by the following features:

• A longitudinal bore extending in the actuator pin for receiving the locking pin and one or more transverse bores cutting the longitudinal bore,
• - A formed on the locking pin first Stützflä che and a housing formed in the second support surface, wherein at least one of the support surfaces relative to the direction of travel is inclined,
• - And one or more locking body, which are arranged movably in the transverse bores and clamped in the rest position between the support surfaces.

at such, based on form or frictional engagement detent only small effective areas are required to the respective Keep actuator pin securely in its rest position. In contrast to the producible holding forces are the required Forces to release the detent by a multiple less, where appropriate, in addition to the force of the locking pin acting further spring means only between the locking bodies and the friction surfaces acting on the support surfaces to be overcome.

Of the or the latching bodies are preferably designed as spheres, as a mass-produced extremely low-cost product Wälzkörperfertigung be removed. It can three balls and three evenly over provided the periphery of the actuator pin distributed transverse bores be. This arrangement is compared to only one locking body insofar advantageous as either identical dimensioning the locking body greater holding forces can be produced or smaller dimensions of the locking body - accordingly a further reduced space requirement of Rastierung - the possibly already sufficient holding force only a detent body can be generated. On the other hand, the arrangement of circumferentially distributed by 120 ° Balls for a mechanically favorable, centered support of the locking pin in the longitudinal bore of the Aktuatorstifts. Yet are of course also arrangements with only one, two, four or more balls possible.

Furthermore The balls can be self-locking between the support surfaces be clamped, the support surfaces a constant or decreasing in the retraction distance to each other. For example, the second support surface run parallel to the direction of movement of the actuator pin and part a production-wise continuous cylindrical longitudinal guide be for the actuator pin. In the design interpretation The support surfaces are natural both the spring forces and the friction conditions to consider at the ball support surface contacts so that for a perfect function of the detent required range of self-locking on these contacts not will leave.

there It is expedient that the first support surface at the locking pin in the extension radially tapers and that the support surfaces are parallel to each other. In the case of rotationally symmetrical support surfaces then the support surfaces circular frustum-shaped educated. This embodiment allows a special low-wear sliding or rolling contact between the balls and the support surfaces when the actuator pin leaves the resting position and reaches it again.

Brief description of the drawings

Further Features of the invention will become apparent from the following description and from the drawings, in which embodiments an electromagnetic actuator are shown. Provided not otherwise stated, are the same or functionally identical Components or features provided with the same reference numbers. Show it:

1 a first embodiment of an actuator with four actuator pins in longitudinal section;

2 the adjusting device according to 1 in the lower view;

3 a second embodiment of an actuator with three actuator pins in longitudinal section;

4 the adjusting device according to 3 in the lower view and

5a C the adjusting device according to 3 with their different Bestromungszuständen for corresponding actuation of the actuator pins.

Detailed description the drawings

The 1 and 2 disclose an electromagnetic actuator 1 , which serves to control a five-stage variable stroke valve train with sliding cam pieces, as in principle from the cited above DE 196 11 641 C1 is known. At the actuator 1 it is a unit which can be mounted in the cylinder head of an internal combustion engine and has a housing 2 and arranged side by side in alignment, hollow cylindrical actuator pins 3 , The four trained as equal parts actuator pins 3.1 to 3.4 are in longitudinal guides 4 of the housing 2 stored side by side (see also the in 2 illustrated bottom view of the actuator 1 ) and can independently between one in the housing 2 retracted NEN rest position (as shown) and one from the housing 2 extended working position (not shown) back and forth.

The actuator pins 3 are in the working position in engagement with one on the cam piece formed, bidirectional axial slide with two intersecting sliding grooves to move the cam piece by the amount of a cam width. The relevant operating principle is from the cited above DE 10 2007 051 739 A1 known and can be summarized to the effect that always only one of the Aktuatorstifte 3 extends into the axial slide and, depending on the current initial position of the cam piece cooperates with one of the two displacement grooves to move the cam piece in one or the other axial direction. An immediate successive extension of the same actuator pin 3 causes a back and forth shift of the cam piece, while a successive extension of directly adjacent actuator pins 3 leads to a successive displacement of the cam piece in the same axial direction. In this arrangement, there are a number of n-1 actuator pins 3 (Present four actuator pins) to illustrate an n-stage stroke variability of the valve train (in this case five stages) sufficient.

The spring means - here helical compression springs 5 - In the extension direction kraftbeaufschlagten actuator pins 3 are held by detents in the rest position. A release of the detents is done by controllable locking pins 6 , also as equal parts 6.1 to 6.4 formed and relative to the Aktuatorstiften 3 are displaced in the direction of travel.

The mutually identical detents are each by a in Aktuatorstift 3 extending longitudinal bore 7 and these cutting cross holes 8th , one at the locking pin 6 trained first support surface 9 and one in the housing 2 trained second support surface 10 and three locking bodies in the form of balls 11 educated. The in the evenly on the circumference of the Aktuatorstifts 3 distributed transverse bores 8th movably arranged balls 11 are in the rest position of the actuator pin 3 between the support surfaces 9 and 10 clamped. For this purpose, the tapered in the longitudinal bore 7 extending end portion 12 of the locking pin 6 conical in the extension direction of the actuator pin 3 so that the first support surface 9 forms the outer circumferential surface of a circular truncated cone. The second support surface 10 in the case 2 runs at a constant distance to and thus forms the inner circumferential surface of a circular truncated cone.

The locking pins 6 are each by another spring means - here a helical compression spring 13 - Also subjected to force in the extension direction. The angle of inclination of the supporting surfaces 9 . 10 opposite the direction of travel of the actuator pin 3 is taking into account the on the locking pin 6 and the actuator pin 3 acting spring forces and the friction conditions on the ball-support surface contacts chosen so that the balls 11 self-locking between the support surfaces 9 . 10 are clamped and so the actuator pin 3 secure in the rest position. The inclination angle is presently about 5 °.

The mutually concentric helical compression springs 5 . 13 supported on the one hand in the housing 2 pressed bushes 14 and on the other hand on annular end faces 15 and 16 the actuator pins 3 or the locking pins 6 from. The locking pins 6 are electromagnetically kraftbeaufschlagt to release the detents in the retraction of the actuator pins 3 shifted and are for this purpose at their the actuator pins 3 remote end portions 17 with permanent magnets attached thereto 18 Mistake. According to the invention, these are magnetized in a double pole axially, in the direction of travel of the actuator pins 3 with respect to their north and south poles designated N and S alternately oriented opposite to each other and in pairs each of the magnetic field of a single electromagnet 19 exposed.

Essential components of the likewise formed as equal parts and through a housing wall 20 of magnetically conductive material separated electromagnets 19 are each a magnetic coil 21 and a stationary core area 22 , The reversible DC power supply of the solenoid coils 21 via a connector 23 , The coaxial in the solenoid 21 extending core area 22 points on the part of the permanent magnets 18 a shoulder on which has a flat contact surface 24 for the locking pins 6 forms. A strongly adhering system of permanent magnets 18 at the contact surfaces 24 This avoids the end sections 17 the locking pins 6 opposite the permanent magnets 18 raised and this always a corresponding minimum distance to the contact surface 24 exhibit.

To the operation of the actuator 1 : Starting point is their de-energized state, in which all actuator pins 3 locked in their rest position. Is attached to the one electromagnet 19.1 Voltage applied with a first polarity (+/-) - the electromagnet 19.2 remains de-energized - so the resulting with the marked SN alignment magnetic field pulls the rectified poled permanent magnet 18.2 and abuts the oppositely poled permanent magnet 18.1 from. While the ejected permanent magnet 18.1 , the associated locking pin 6.1 and consequently also the associated actuator pin 3.1 due to the associated undissolved detent remain at rest, the with the permanent magnet 18.2 tightened locking pin 6.2 up to the contact surface 24 shifted in the retraction. The associated detent detaches itself by the clamping effect of the balls 11 opposite the support surfaces 9 . 10 canceled becomes. While the balls 11 the inclination of the second support surface 11 in the case 2 follow and move radially inward in the cross holes 8th shift, becomes the actuator pin 3.2 by the force of the helical compression spring 5 driven into his working position. The electromagnet 19.1 is then de-energized, so that the tightened locking pin 6.2 by the force of the helical compression spring 13 returns to its original position.

As mentioned above, the engaged actuator pin 3.2 pushed back into its rest position by a radially rising outlet region of the sliding groove extending on the cam piece and locked there again. This is done by making the balls 11 the inclined course of the first support surface 9 at the locking pin 6.2 follow, radially outward in the cross holes 8th shift and under self-locking between the support surfaces 9 . 10 be clamped.

The actuation of the directly adjacent actuator pin 3.1 is initiated by the fact that to the electromagnet 19.1 Voltage is applied with the second polarity (- / +) reversed to the first polarity (+/-). The electromagnet 19.2 remains again without power. The reverse direction of action of the now developing magnetic field with opposite to the representation of opposite NS alignment abuts the then oppositely poled permanent magnet 18.2 and pull the then rectified poled permanent magnet 18.1 at. The further control curve of the actuator pin 3.1 takes place in an identical manner as above for the Aktuatorstift 3.2 explained.

The actuation of the other two actuator pins 3.3 and 3.4 is done by energizing the electromagnet 19.2 and otherwise in the same way as for the actuator pins 3.1 and 3.2 explained.

The 3 and 4 show an actuator 1' , which also has two electromagnets 19 , but only three actuator pins 3 having. Also this adjusting device 1' is for use in a variable stroke valve train with sliding cam pieces and - the number of actuator pins 3 accordingly - four-stage stroke variability provided. The adjusting devices 1 and 1' have identical to each other detents of the actuator pins 3 essentially differ only in that in the adjusting device 1' the middle permanent magnet 18.2 in the magnetic sphere of influence of both electromagnets 19 is and depending on their energization of one or both electromagnets 19 is charged with force. This dependence is in the 5a to 5c illustrated. As a contact surface for the middle locking pin 6.2 serves one between the core areas 22 running stop 25 that with the flat contact surfaces 24 flees.

The actuation of the actuator pin 3.1 takes place according to 5a by energizing the electromagnet 19.1 with a first polarity (+/-) while the electromagnet 19.2 remains energized. The resulting with the marked NS orientation magnetic field pulls the rectified poled permanent Magne th 18.1 and abuts the directly adjacent thereto permanent magnet 18.2 due to its opposite polarity. The application of force to the permanent magnet 18.3 remains due to the housing wall made of magnetically conductive material 20 between the electromagnets 19 (magnetic short circuit) and the magnetic shielding effect by the permanent magnet 18.2 negligible small.

The actuation of the actuator pin 3.2 takes place according to 5b by energizing both electromagnets 19 with a polarity opposite to the first polarity (+/-) (- / +). The resulting corresponding with the marked SN alignment magnetic fields pull the rectified poled permanent magnet 18.2 and abut the on both sides adjacent permanent magnets 18.1 and 18.3 due to their oppositely directed polarity.

The actuation of the actuator pin 3.3 takes place according to 5c , In this case, the electromagnet 19.2 energized with the first polarity (+/-) while the electromagnet 19.1 remains energized. The magnetic field generated with the marked NS alignment now pulls the rectified poled permanent magnet 18.3 and abuts the directly adjacent permanent magnet 18.2 due to its opposite polarity. Analogously to 5a Now remains the application of force to the permanent magnet 18.1 due to the magnetically conductive housing wall 20 between the electromagnets 19 and the magnetic shielding effect by the permanent magnet 18.2 negligible small.

1

locking device

2

casing

3

actuator pins 3.1 to 3.4

4

longitudinal guide

5

Helical compression spring

6

locking pins 6.1 to 6.4

7

longitudinal bore

8th

cross hole

9

first support surface

10

second support surface

11

Bullet

12

end of the locking pin

13

Helical compression spring

14

Rifle

15

face on the actuator pin

16

face at the locking pin

17

end of the locking pin

18

permanent magnets 18.1 to 18.4

19

electromagnets 19.1 and 19.2

20

housing wall

21

solenoid

22

stationary core area

23

Connectors

24

contact surface at the core area

25

attack

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 102004021376 A1 [0002]
• - DE 19611641 C1 [0003, 0028]
• - DE 102006051809 A1 [0004, 0012]
• DE 102007024598 A1 [0005]
• WO 03/021612 A1 [0006]
• - DE 202008008142 U1 [0007]
• - DE 102009010949 A1 [0009]
• - DE 102007051739 A1 [0009, 0012, 0029]

Claims (11)

Electromagnetic actuator ( 1 . 1' ) with a housing ( 2 ) and actuator pins ( 3 ), which between one in the housing ( 2 ) retracted rest position and one from the housing ( 2 ) extended working position independently movable and side by side in the housing ( 2 ) and spring devices ( 5 ) are subjected to force in the extension direction, as well as the actuator pins ( 3 ) associated locking pins ( 6 ), the actuator pins ( 3 ) hold by means of detents in the rest position and in the direction of movement of the actuator pins ( 3 ) are displaceable relative to these, wherein the locking pins ( 6 ) at the actuator pins ( 3 ) facing away from end portions ( 17 ) with two-pole magnetized in the direction of travel permanent magnet ( 18 ) are provided and released to release the detents electromagnetically kraftbeaufschlagt in the retraction direction, characterized in that the adjusting device ( 1 . 1' ) at least two independently energizable electromagnets ( 19 ) with reversible direction of the magnetic field and at least three actuator pins ( 3 ), wherein the electromagnets ( 19 ) two directly adjacent permanent magnets ( 18 ) force, the polarity of which are aligned opposite to each other. Adjusting device ( 1 . 1' ) according to claim 1, characterized in that the electromagnets ( 19 ) by a housing wall ( 20 ) are separated from each other from magnetically conductive material. Adjusting device ( 1 ) according to claim 1, characterized in that two electromagnets ( 19 ) and four actuator pins ( 3 ) are provided. Adjusting device ( 1' ) according to claim 1, characterized in that two electromagnets ( 19 ) and three actuator pins ( 3 ) are provided, wherein the middle permanent magnet ( 18.2 ) of both electromagnets ( 19 ) is subjected to force. Adjusting device ( 1 . 1' ) according to claim 1, characterized in that the locking pins ( 6 ) of other spring means ( 13 ) are subjected to force in the extension direction. Adjusting device ( 1 . 1' ) according to claim 1, characterized in that the detents are each formed by the following features: - one in Aktuatorstift ( 3 ) extending longitudinal bore ( 7 ) for receiving the locking pin ( 6 ) and one or more of the longitudinal bore ( 7 ) intersecting transverse bores ( 8th ), - one on the locking pin ( 6 ) formed first support surface ( 9 ) and one in the housing ( 2 ) formed second support surface ( 10 ), wherein at least one of the support surfaces ( 9 . 10 ) inclined relative to the direction of travel, - and one or more locking body ( 11 ) in the transverse bores ( 8th ) and in the rest position between the support surfaces ( 9 . 10 ) are clamped. Adjusting device ( 1 . 1' ) according to claim 6, characterized in that the detent body ( 11 ) are formed as balls. Adjusting device ( 1 . 1' ) according to claim 7, characterized in that three balls ( 11 ) and three evenly over the circumference of the Aktuatorstifts ( 3 ) distributed transverse bores ( 8th ) are provided. Adjusting device ( 1 . 1' ) according to claim 7, characterized in that the balls ( 11 ) self-locking between the support surfaces ( 9 . 10 ) are clamped, wherein the support surfaces ( 9 . 10 ) have a constant or a decreasing distance in the retraction direction to each other. Adjusting device ( 1 . 1' ) according to claim 9, characterized in that the first support surface ( 9 ) radially tapered in the extension direction and that the support surfaces ( 9 . 10 ) parallel to each other. Adjusting device ( 1 . 1' ) according to claim 10, characterized in that the support surfaces ( 9 . 10 ) are formed truncated circular.