DE102009042888A1 - Electromagnetic proportional actuator has anchor which is guided into direction in axially displaceable manner, where direction is directed to pole core with control cone - Google Patents

Abstract

The electromagnetic proportional actuator (46) has an anchor (26) which is guided into the direction in axially displaceable manner. The direction is directed to a pole core (16) with a control cone (15). The outer diameter of the control cone is tapered by an inner diameter in the direction along an area. The outer diameter and the inner diameter expand in a subsequent end area.

Description

The invention relates to an electromagnetic proportional actuator according to the preamble of patent claim 1.

From the from Linsmeier, Klaus-Dieter, "Electromagnetic Actuators", 1995, ISBN 3-478-93134-7 an electromagnetic proportional actuator is already known, in which radially within a coil, an armature is guided axially displaceable in the direction of a pole core with a control cone direction. The outer diameter of the control cone is tapered in the armature-facing direction along a region of a constant inner diameter. On pages 30 ff. The function of this tax bonus is explained in detail.

The object of the invention is to provide an electromagnetic proportional actuator which, even with a larger magnet stroke, offers a large degree of freedom in the magnetic stroke characteristic-in particular with a linear force / displacement curve.

This object is achieved with the features of claim 1.

According to the invention a shaping of the control cone is proposed, which allows such a linear force / displacement curve and yet is technically finished. It has thus been found that a control cone which becomes very thin over a large axial length enables a linear force / displacement curve. However, such a control cone is associated with manufacturing disadvantages and space limitations. The shaping according to the invention with an end region which widens again both on the outer diameter and on the inner diameter has the same linear force / displacement profile. However, this "trumpet shape" according to the invention can be produced. For example, the control cone can be turned, milled, cross rolled or extruded. In addition, the control cone can be made in one piece with the pole core or in two parts of a tube and a ring.

With the trumpet shape, a combination of air gap controlled and cone cross section controlled magnetic characteristic can be realized. That is, in the claimed control cone shape, the magnetic flux is not controlled mainly by the change of the wall thickness of the control cone. Instead, the magnetic flux across the width of the air gap is controlled by the increasing distance between the control cone and armature.

By means of this trumpet-shaped control cone shape, it is also possible with larger magnetic strokes to create different yet precisely maintainable magnetic stroke characteristics.

A particularly linear force / displacement curve can be achieved when the trumpet-shaped end region expands with increasing slope. The wall thickness of the end region can remain constant in a particularly advantageous manner. In further embodiments, the wall thickness can also decrease.

• – regelbare Querdifferentialsperren,
• – regelbare Längsdifferentialsperren,
• – Torque Vectoring Systeme und
• – die Ankupplung einer zusätzlichen Achse bei einem zuschaltbaren Allradantrieb.

The control cone can be used in a particularly advantageous manner in an electromagnetic proportional actuator for a hydraulic actuator for actuating a multi-plate clutch, since the electromagnetic proportional actuator for such an actuator for applying the hydraulic pressure must be very large and dimensioned with a long linear stroke. Applications for such Lammellenkupplungen are particular

• - adjustable transverse differential locks,
• - adjustable longitudinal differential locks,
• - Torque Vectoring Systems and
• - The coupling of an additional axle in a switchable four-wheel drive.

Such applications are partially in the US 4,862,769 and the WO 2008/004974 A1 shown.

Here are to be regarded as a multi-plate clutch also Lameilenbremsen.

To compensate for leakage losses of the hydraulic fluid of this hydraulic pump, a corresponding device may be provided.

Further advantages of the invention will become apparent from the other claims, the description and the drawings.

The invention is explained in more detail with reference to an embodiment.

Show

1 an electromagnetic actuator with a pole core and

2 the pole core 1 in a view as an item.

1 shows a sectional view of a hydraulic actuator 1 with an electromagnetic proportional actuator 46 , The actuator 1 is attached to a receiving housing, not shown, and brings the hydraulic pressure for a multi-plate clutch, with the The rear axle of a standard front-wheel drive vehicle can be integrated into the drive.

The proportional actuator 46 includes a coil 2 to which a supply voltage is applied via a connector, not shown. This supply voltage may in particular be a DC voltage. Likewise, an AC voltage via bridge rectifier, a pulse width modulated voltage or it can also dither signals are applied to a DC voltage. With the actuator 1 A hydraulic pressure can be generated which is largely proportional to the applied current and independent of the path. Responsible for this is mainly the shape of a Polkerns 16 or from its tax credit 15 ,

The sink 2 is with a coil carrier 3 made of non-conductive plastic completely encapsulated. In this case, the bobbin has 3 at the front end a thickened waistband 4 on, from the cast approaches 22 in a magnetizable reinforcement plate bushing 25 to grab. This reinforcement plate bushing 25 has at the rear end a radially inwardly bent collar 27 on. The reinforcement plate bush 25 and the coil carrier 3 are in common with the coil 2 in a set cup-shaped housing 5 made of magnetizable sheet steel. It is approximately at the rear third of the housing 5 paragraph 29 intended. At this paragraph 29 of the housing 5 lies one side of a pole disk 6 at. On the other side of the pole disk 6 the coil is supported 2 from. This pole disk 6 is very fat. This thickness h is necessary because a large diameter D _{A of} an anchor explained below 26 a small radial dimension r of the pole disk 6 necessary. However, such a small radial dimension r implies the transition region of the magnetic flux from the pole disk 6 to the anchor 26 a large area. About the thickness h is also the reinforcing plate bushing 25 on the lateral surface 31 the pole disk 6 to, said the federal government 27 in an annular recess of the pole disk 6 attacks.

Through a centric recess 8th the pole disk 6 protrudes a magnetizable steel sleeve 10 , This steel sleeve 10 relies on a paragraph 11 in the back on a pot bottom 9 the cup-shaped housing 5 pointing direction axially on the pole disk 6 from. The steel sleeve 10 is provided on the inner wall with a friction-reducing release layer, which may be, for example, a bonded coating, PTFE or a nickel-PTFE coating. Alternatively, the anchor can also be used 26 be provided on the lateral surface with such a separation layer.

On the front end of the steel sleeve 10 is a thin-walled non-magnetizable steel tube 13 attached, which at its other end to a cylindrical area 7 of the pole core 16 is plugged. For easier attachment of the steel pipe 13 and for linearization of the magnetic force is the steel sleeve 10 at the pole core 16 facing radially outward conically chamfered. An in an annular groove on the outer circumference of the annular disc 14 inserted O-ring 17 seals the annular disc 14 hydraulic pump 1 off, so no hydraulic fluid from the housing 5 can get.

The Polkern 16 has a radially rearward within the coil 2 extending tax bonus 15 and a forwardly extending connecting pin 18 on. This front end pin 18 is inserted in a manner not shown in a bore of said receiving housing and thus centered the actuator 1 opposite the receiving housing. Here is the actuator 1 about holes 32 on a flange 19 of the housing 5 firmly bolted to the receiving housing. For the preparation of this compound but also, for example, an axial circlip or a pin according to DE 10 2007 030 165 be used. Furthermore, the end pin 18 alternatively have an external thread and be screwed into the receiving housing.

In a position radially between the control cone 15 and the connecting pin 18 are equalization holes 20 . 21 provided an anchor space 28 when disengaging a piston 23 supply with coming from the tank T hydraulic fluid or this again when engaging the piston 23 into the tank T lead.

The piston protrudes 23 for producing the pressure in a high pressure area 30 axially in a centric continuous recess 38 of the pole core 16 , The piston 23 has a radial play to the pole core 16 on. The piston 23 is made of a non-magnetizable material and immovable with the anchor 26 connected. This is the piston 23 in a recess of the anchor 26 pressed. A one-sided opening sealing ring 24 is provided, which bridges the radial clearance and thus the pressure to be set high pressure area 30 against the front anchor space 28 within the tax bracket 15 seals. This is this sealing ring 24 in an annular groove at the end of the piston 23 used and is located on a cylinder bore or inner wall 42 the central recess 38 in the pole core 16 at.

As in 2 can be seen, the pole core 16 at the anchor room 28 facing side a double-slotted guide ring 39 on. This slotted guide ring 39 has 3 functions.

• – sich einerseits an einer stirnseitig in den Polkern 18 eingelassenen Ringnut 33 und
• – sich andererseits an einer stirnseitig in den Anker 26 eingelassenen Ringnut 34

abstützt. The first function is the guide ring 39 a helical compression spring 40 , Which

• - On the one hand on a front side in the pole core 18 taken in ring groove 33 and
• - On the other hand, on a front side in the anchor 26 taken in ring groove 34

supported.

The second function is performed by the guide ring 39 the function of an anti-stick disc, as he is in the on the anchor 26 pointing direction is tapering so that only a small magnetic adhesive surface for the anchor 26 is available. It benefits that the anchor 26 in the usual operating range of the actuator 1 only rarely and then strongly damped to stop the guide ring 39 comes.

The third function is provided by slots 35 in the guide ring 39 for that the high pressure area 30 with a correspondingly inclined installation position of the actuator 1 with piston engaged 23 is vented and on the other hand as a safety function in case of interruption of the power supply, the multi-plate clutch free of pressure.

The piston 23 is with a blind hole 36 and a transverse bore 37 provided so that the anchor space 28 about a centric in the anchor 26 incorporated channel 41 with the room 43 behind the anchor 26 is connected, so that a pressure equalization of the armature space 28 with the room 43 is made.

Radially outside the piston 23 and the helical compression spring 40 is the tax bonus 15 , This tax bonus 15 extends from the annular disk 14 starting axially over the end face facing it 44 of the anchor 26 out.

This forms an overlap area which has a sufficiently high starting force of the armature 26 ensures.

Starting from the ring disk 14 indicates the outer diameter of the control cone 15 First, the consistently cylindrical area 7 on which the steel pipe 13 and the covenant 4 are set up. This first area 7 closes axially behind another area 8th on, which is in the anchor 26 pointing direction at the outer diameter of the control cone 15 rejuvenated. By contrast, the inner diameter remains the same over this taper. From the end of this taper - ie after about ¾ of the total distance - the outer diameter and the inner diameter widen in a subsequent end region 45 back up. Over the length of the widening outer and inner diameter thereby increasing the slope. The wall thickness of the trumpet-shaped widening end region 45 thus remains constant until the end.

By means of this special shape is achieved that the force of the armature increases almost linearly over the axial displacement.

The wall thickness of the end area does not have to remain constant. Alternatively, the pitch of the inner diameter may increase to a greater extent than the pitch of the outer diameter. Such a configuration has the consequence that the wall thickness of the trumpet-shaped widening end region 45 decreases towards the end.

The non-magnetizable steel components may in particular consist of an austenitic steel. However, these components can also be made of another non-magnetizable material, such as brass. Also, a Reibwertvermindernde coating or release layer may be provided on the piston and / or the inner wall of the pole core. Or it can be used a plastic.

The piston can also be axially resistant to the armature. Ie. radial and / or rotational relative mobility would be possible. A possible connection of the piston with the armature is a snap ring, which engages on the one hand in a rounded circumferential outer annular groove of the piston and on the other hand in a rounded circumferential inner annular groove of the armature. For such a connection, instead of a snap ring and a closed circumferential hose spring can be used, as such is already known from radial shaft seals. Such a hose spring is considerably softer and less sharp than a snap ring. Thus, even a piston made of a brittle material, such as a thermosetting plastic can be used without the risk of chipping of parts of the plastic piston during assembly. A practical thermoset plastic is commercially available under the brand name Vyncolit.

The piston can also be designed as a plunger and does not end in the recess of the pole core but can stand beyond the pole core.

The electromagnetic proportional actuator need not be associated with an electro-hydraulic unit. It is also possible to operate a non-hydraulic piston directly with the electromagnetic proportional actuator. Such designed as a solenoid solenoid proportional actuator is for example in the and from Linsmeier, Klaus-Dieter, "Electromagnetic Actuators", 1995, ISBN 3-478-93134-7 shown.

Also in the application of the electromagnetic proportional actuator for a hydraulic unit, this must not be designed as an actuator for a multi-plate clutch. It is also possible to use the electromagnetic proportional actuator for a valve such as a volumetric flow control valve, a pressure regulating valve or a cartridge valve. For example, a consumer to be hydraulically controlled by a valve is a vane-type camshaft phaser.

Instead of the slots 35 can also be provided other forms of recesses, such as holes or holes.

The pole core does not have to be made in one piece. It can be made in particular of two parts, with a rather tubular part is inserted into a rather annular part. This makes a post-processing necessary.

The described embodiments are only exemplary embodiments. A combination of the described features for different embodiments is also possible. Further, in particular not described features of the device parts belonging to the invention are to be taken from the geometries of the device parts shown in the drawings.

LIST OF REFERENCE NUMBERS

1

actuator

2

Kitchen sink

3

coil carrier

4

Federation

5

casing

6

pole disk

7

cylindrical area

8th

another area

9

pot base

10

steel sleeve

11

paragraph

12

13

steel tube

14

washer

15

control cone

16

pole core

17

O-ring

18

connection thread

19

flange

20

compensating bore

21

compensating bore

22

cast approaches

23

piston

24

seal

25

Support panel socket

26

anchor

27

Federation

28

armature space

29

paragraph

30

High pressure area

31

lateral surface

32

drilling

33

end-face annular groove

34

end-face annular groove

35

slot

36

Blind hole

37

cross hole

38

Recess of the pole core 16

39

guide ring

40

Helical compression spring

41

channel

42

inner wall

43

room

44

face

45

end

46

electromagnetic proportional actuator

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

• US 4862769 [0010]
• WO 2008/004974 A1 [0010]
• DE 102007030165 [0023]

Cited non-patent literature

• Linsmeier, Klaus-Dieter, "Electromagnetic Actuators", 1995, ISBN 3-478-93134-7 [0002]
• Linsmeier, Klaus-Dieter, "Electromagnetic Actuators", 1995, ISBN 3-478-93134-7 [0039]

Claims (11)

Electromagnetic proportional actuator ( 46 ), in which radially inside a coil ( 2 ) an anchor ( 26 ) into a pole core ( 16 ) with a tax bonus ( 15 ) pointing direction axially displaceable, wherein the outer diameter of the control cone ( 15 ) in the on the anchor ( 26 ) pointing direction along a region ( 8th ) tapered over a constant inner diameter, characterized in that the outer diameter and the inner diameter in a subsequent end region ( 45 ) expand. Electromagnetic proportional actuator according to claim 1, characterized in that the outer diameter and the inner diameter in the end region ( 45 ) with increasing slope. Electromagnetic proportional actuator according to claim 2, characterized in that over the end region ( 45 ) the wall thickness is at least almost constant. Electromagnetic proportional actuator according to one of the preceding claims, characterized in that the region ( 8th ), over which the outer diameter tapers, longer than the widening end portion ( 45 ). Electromagnetic proportional actuator according to one of the preceding claims, characterized in that the proportional actuator ( 46 ) is associated with an electro-hydraulic unit and the armature ( 26 ) is supported on a plunger which axially into a central recess ( 38 ) of a pole core ( 13 protrudes. Electromagnetic proportional actuator according to claim 5, characterized in that the electromagnetic unit as a hydraulic actuator ( 1 ) and the plunger as a piston ( 23 ), wherein the armature ( 26 ) has a diameter which is greater than the diameter of the axially fixed with this anchor ( 26 ) connected piston ( 23 ), one on an inner wall ( 42 ) of the recess ( 38 ) fitting gasket ( 24 ) so that in the fluid-filled centric recess ( 38 ) A hydraulic pressure can be produced. Electromagnetic proportional actuator according to claim 6, characterized in that in the pole core ( 16 ) a channel (compensation holes 21 . 22 ), one between the pole core ( 16 ), the anchor ( 26 ) and a non-magnetic socket ( 13 ) enclosed space ( 28 ) connects to a tank (T), the seal ( 24 ) is designed to open on one side, so that hydraulic fluid along this seal ( 24 ) from the room ( 28 ) in one of the piston ( 23 ) under pressure to be set high pressure area ( 30 ), but of the seal ( 24 ) in the from the high pressure area ( 30 ) to the room ( 28 ) pointing direction is locked, provided that the piston ( 23 ) is not in its maximum engaged position. Electromagnetic proportional actuator according to one of the claims 5 to 7, characterized in that the plunger coaxial with a helical compression spring ( 40 ) is arranged, on the one hand at the pole core ( 16 ) and on the other hand at the anchor ( 26 ) is supported. Electromagnetic proportional actuator according to claim 8, characterized in that the helical compression spring ( 40 ) on a guide ring ( 39 ), the recesses (slots 35 ) for guiding hydraulic fluid from an area in front of the ram to a room ( 28 ) within the proportional actuator ( 1 ) having. Electromagnetic proportional actuator according to one of the preceding claims, characterized in that the magnetic flux at the front end of the proportional actuator ( 46 ) over the pole core ( 16 ), in a central area via a magnetic housing ( 5 ) and behind the coil ( 2 ) via a pole disk ( 6 ), wherein the pole disk ( 6 ) has a thickness (h) which is greater than the wall thickness of the magnetic housing ( 5 ). Electromagnetic proportional actuator according to claim 2, characterized in that over the end region, the pitch of the inner diameter increases to a greater extent than the pitch of the outer diameter.

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