DE102007061862A1 - Switchable magnet arrangement as an actuating element for a valve or other functional elements - Google Patents

Abstract

A switchable magnet arrangement (1) as an actuating element or actuator for a valve or other functional elements with a magnetizable housing, an excitation coil (4) arranged at least partially in the magnetizable housing, an armature (6) axially movable in a bearing when current is applied to the exciter coil (4) ), which comprises a directed in the direction of actuation of the actuator, guided in a bearing axial ram (7), one of the end faces of the housing final yoke (5) and a the other end face of the housing final cone-shaped guide body (9), wherein the Guide body (9) has an axial passage for the plunger (7) should be improved so that the pressure balance in the magnet can be realized without compensation holes in the anchor piston and / or in the cone. For this purpose, it is proposed that the armature (6) and / or the yoke (5) and / or the cone-shaped guide body (9) and / or the bearing is at least surrounded by or surrounds a magnetically conductive, media-permeable material.

Description

The The invention relates to a switchable magnet arrangement as an actuating element or actuator for a valve or other functional elements with a magnetizable housing, one at least partially in the magnetizable housing arranged exciter coil, an axially energized upon energization of the excitation coil Anchor, an anchor piston and one in the direction of actuation the actuator directed axial actuating rod comprises, a one of the end faces of the housing final Yoke and one the other end of the housing final conical guide body, wherein the Guide body an axial penetration for having the actuating rod.

Such a magnet arrangement is for example from DE 102 38 840 A1 known as camshaft adjuster.

At the connections of electromagnetically driven valves There are certain connection pressures. these can unwanted repercussions on the position of Valve have. To prevent this, one leads the pressure level a connection into the magnet and ensures that that the surfaces on which the pressure acts are the same size, so that a pressure equalization is possible. For transmission this pressure into the interior of the anchor space are the inside of the magnet arranged parts, such as the armature piston and / or the Cone and sometimes the yoke, with longitudinal and / or transverse bores Mistake. The preparation of these pressure equalization holes, in particular in the anchor piston and the cone, is complicated and expensive. Another additional disadvantage may be that if the Transverse holes are not arranged symmetrically, this is unbalanced Force effects of the electromagnet and thus increased switching hysteresis can lead.

such Electromagnets are z. B. in the automotive industry as a proportional magnet used for camshaft adjustment. The proportional, speed-dependent Adjustment of intake / exhaust camshaft used in car engines for torque increase at low speeds and for pollutant and consumption reduction. The proportional solenoid used is in conjunction with a 4/2-way proportional valve in the engine compartment bolted directly to the cylinder head.

The The input signal of the magnet is the pulse width modulated supply voltage of the electrical system. By changing the duty cycle the voltage becomes the valve piston position via the proportional solenoid, or the oil volume flow variably controlled.

By the change of the volume flow will be the inlet and Exhaust camshaft adjusted relative to the crankshaft. This adjustment influences the timing of the exhaust and intake valves. The main advantage A camshaft adjustment is the reduction of exhaust emissions and the improvement of the torque curve.

Of the Proportional magnet is characterized by a low number of components and by simple assembly.

From the EP 1 667 177 A1 It is known to make the anchor piston partly from a sintered material. This applies in particular to the axial region of the armature piston, which serves as a cover for the anchor rod. It is proposed a material combination of sintered non-magnetic with magnetic iron material, so as to obtain the magnetic properties (extension of the flux guide in the armature) and at the same time improved properties against wear for the anchor rod. A possible pressure equalization is in the EP 1 667 177 A1 not mentioned or suggested.

outgoing From this prior art, it is the object of the invention, the Pressure equalization in the magnet without compensation holes in the anchor piston and / or to realize in the cone.

The The object is achieved by the features of claim 1. Instead of machining from solid material produced anchor piston, yoke or cone is inventively at least one of these components of a magnetically conductive Surround the material for media such as air or oil (Gases or liquids) permeable to pressure equalization is. Where is the thickness and / or area of the cover depending on the required pressure compensation and application area.

It But it is also possible, the anchor piston and / or the yoke and / or the bearings and / or the cone-shaped guide body from the magnetically conductive, media-permeable Material to ensure optimal pressure equalization.

It has proven to be advantageous if the magnetically conductive, media-permeable material an open-pored, magnetic conductive, foam-like material, for example sintered Metal is.

According to the invention machined the running surfaces of the anchor piston mechanically be.

Especially the switchable magnet arrangement can be a lifting magnet, for example a proportional magnet.

In Particularly advantageously, the open-pored, magnetically conductive, foamy material sintered, ferrous, possibly with more Alloy elements contain mixed material.

The switchable magnet arrangement can according to the invention as Proportional magnet for camshaft adjustment or as actuator for a variable throttle is used. They are acting as an actuator used in pneumatic, hydraulic and air conditioning systems.

The Invention is described below with reference to the drawing Embodiments explained in more detail. Show it:

1 a proportional magnet according to the invention and

2 a further embodiment of a proportional magnet according to the invention.

In the 1 is a switchable magnet arrangement according to the invention 1 , For example, a proportional solenoid for camshaft adjustment, with a magnetizable cup-shaped housing part 2 in which one, on a bobbin 3 For example, plastic mounted excitation coil 4 is arranged. A substantially plate-shaped magnetizable yoke 5 closes in the axial direction of the open cup-shaped housing part 2 from. In the center of the exciter coil 4 is an axially movable anchor 6 stored. Central in the anchor 6 is a pestle 7 arranged as an actuating rod, the front, out of the magnet assembly out end 8th as actually switching element for other functional parts, such as a valve spool, is used.

The pestle 7 is also in a firmly fitted guide body 9 held axially movable. This is cone-shaped and in the axial direction below at a distance to axially extending flange portions 10 of the yoke 5 held.

The guide body 9 is in a recess 11 in the bottom part of the cup-shaped housing part 2 held and radially closes directly to the edge region 12 the recess 11 at. This ensures the magnetic flux between these parts.

Due to the axial distance between the cone-shaped guide body 9 and the flange areas 10 of the yoke 5 This results in an air gap to be bridged for the magnetic field lines. With energization of the exciter coil 4 an axial force acts on the armature 6 so that it executes a stroke and during this movement the plunger pressed with it 7 entrains, for example, acts on a valve spool and this adjusted.

The anchor 6 with the ram held therein 7 and the cone-shaped guide body 9 are in a pressure-tight anchor space 13 held. This is through a thin-walled sleeve 14 sealed. The sleeve 14 is on the the recess 11 surrounding edge area 12 of the cup-shaped housing part 2 axially fixed, for example, welded by a laser welding process, and thus enables the direct radial contacting of cup-shaped housing part 2 and cone-shaped guide body 9 to ensure an uninterrupted magnetic flux.

The connection between the sleeve 14 and the cup-shaped housing part 2 is in the DE 102 38 840 A1 described in detail. The sleeve 14 itself may consist of a non-magnetizable stainless steel or the like. It has only a mechanical and sealing, but usually no magnetic function. The sleeve 14 is with a shoulder 15 provided, on the one hand in the pressure-tight anchor space 13 the cone-shaped guide body 9 and on the other hand in the outer space of the coil carrier 3 support.

The thus assembled parts can be inserted into an injection mold and by molding with plastic compound 16 firmly held together. In this case, one or more hold-down devices are provided in the injection molding device, through which the yoke 5 on the cup-shaped housing part 2 be pressed so that in the thus manufactured magnet assembly 1 no interruption of the magnetic flux between said parts can arise. By embedding in the plastic compound 16 one obtains a stable magnet arrangement 1 with low weight.

In the manufacture of the upper part of the housing by means of the plastic compound produced by injection molding 16 can simultaneously a connection flange for the entire magnet arrangement 1 be sprayed, whereby by appropriate design of the injection mold attachment approaches 17 , such as holes for mounting screws in the plastic compound 16 be formed. A cast-in metal reinforcement 18 in the fastening lugs 17 can increase their stability. In addition to the mechanical fastening approaches 17 will also be a plug 19 for an electrical contacting of the exciter coil 4 in the plastic mass 16 integrated. This results in a particularly compact design using a minimum of components. Even in an externally vibration-prone continuous operation a stable contention of all cast parts is guaranteed. The plastic mass 16 additionally isolated the current-charged parts from and to the outside.

With the magnet arrangement 1 can be a rule be formed organ, wherein the valve spool now no longer than unity with the anchor 6 the magnet arrangement 1 trained, but is decoupled from this. As a result, the axial height can be significantly reduced. The valve spool can from the plunger 7 be acted upon in the printing operation against a return spring. For sealing the connection between magnet arrangement 1 and valve can be an O-ring 20 serve.

According to the invention can now anchor 6 , the yoke 5 and / or the bearings 24 respectively. 26 and / or the cone-shaped guide body 9 , which are usually made in a spanender manner of solid material, be at least partially made of an open-pored, magnetically conductive, foam-like material, which is in particular media-permeable. This can be achieved, for example, by the fact that these components, the anchor 6 , the yoke 5 and / or the guide body 9 to be created by sintering.

By virtue of the fact that these components obtain an open-pored structure due to the use of a material produced in a sintering process, internal pressure compensation in the armature space is ensured, which can take place inside the components without additional bores having to be introduced. Required treads for the anchor 6 can be edited if necessary. The impact speed of the mobile anchor 6 at its impact surfaces is mainly dependent on the pore size of the porous material used.

As a suitable open-pored, magnetically conductive, foam-like material, for example, the known from a brochure of the company Hoeganaes with the note 0001-AsPA sintered iron-containing material in a phosphorus alloy with the trade name Ancorsteel ^® can be used, which may be provided for use in such magnet ,

In the 2 is another embodiment of a switchable magnet arrangement according to the invention 21 represented, for example, may be a proportional solenoid for camshaft adjustment. The magnetizable pot-shaped housing part 2 , the coil carrier 3 and the exciter coil 4 as well as the subject matter 1 be constructed. A cup-shaped magnetizable yoke 22 closes the open pot-shaped housing part 2 in the axial direction, the yoke 22 and the cup-shaped housing part 2 are held in the axial direction at a distance. A pestle 23 is in the center of the cup-shaped magnetizable yoke 22 from a sintered warehouse 24 held in an opening of a protruding bearing bush 25 is introduced. Furthermore, the plunger 23 in one in the middle of the cone-shaped guide body 9 arranged abutment 26 made of sintered material. An anchor 27 surrounds the plunger 23 and is connected to it, for example, by welds. The anchor 27 points in his the yoke 22 facing an annular, the plunger 23 surrounded depression in which the above bearing bush 25 intervenes.

In this embodiment, the switchable magnet arrangement 21 becomes the pestle 23 only in the cone-shaped guide body 9 and in the yoke 22 in the two sintered bearings 24 and 26 stored. One of the two sintered bearings 24 or 26 is in a sintered yoke 22 stored, produced in a sintering process in which iron-containing material is sintered, and wherein the sintered materials used are media-permeable, ie, gas and / or liquid-permeable. During the axial stroke of the armature and thus the movement of the plunger 23 becomes the anchor space 13 between the anchor 27 and the housing part 2 changed, with the pressure in this anchor space 13 if necessary to the sintered bearing 24 changed. Through this pumping movement oil can be pumped back and forth, possibly even through the sintered yoke 22 therethrough. It is important to ensure that the porosity of the sintered material may not be particularly large, since certain magnetic properties are required here. The combination of sintered bearings 24 and 26 and sintered yoke 22 lead to improved oil lubrication of the sintered bearings 24 and 26 , and thus to an increase in the service life. The sintered counter bearing 26 can in his pores in the contact area to the plunger 23 Store oil, thereby ensuring oil lubrication of the rod-rod bearing in the first place. The porous sintered yoke 22 however, it ensures the exchange of oil from the anchor space 13 of the anchor 27 to the rear sintered bearing 24 , Without this arrangement, the sintered bearing would have 24 just the gap between sintered bearings 24 and anchor rod 23 for replacement / pressure compensation available.

Due to the embodiments of the switchable magnet assembly according to the invention to obtain a robust bearing having a higher durability due to improved mating a hard piston wall with the sintered bronze. Also, the switchable magnet assembly gets better hysteresis due to reduced friction of the armature 6 or 27 and / or the plunger 7 or 23 ,

additionally you get a solid yoke with improved magnetic Efficiency, so that with the same magnetic force, the installation height of the magnet can be reduced.

By doing that, the material of anchor 6 or 27 , Yoke 5 or 22 and / or cone-shaped guide body 9 According to the invention is formed medially permeable, the components receive an open porous structure, which provides an internal pressure equalization in the armature space 13 ensures. The desired pressure compensation can take place inside the components. Required treads for the anchor 6 or 27 can be edited if necessary.

Since the material itself ensures the desired pressure equalization, expensive and therefore expensive manufacturing processes, such as the introduction of transverse bores, can be dispensed with. An attachment of other components, such as spacers, etc., is still possible. Blind hole, in the anchor 6 or 27 , in the guide body 9 or yoke 5 respectively. 22 Anti-adhesive discs are mounted, can even be created directly in the sintering process itself, so that reduces the cost of reworking.

In particular, with respect to the storage of the projecting from the anchor ram 7 or 23 As an operating rod arise in the use of open-pore material significant advantages. Additional bearings or wear protection layers can be dispensed with, at least for hydraulic applications, since the open-pored structure of the surface allows to store lubricants which, after consumption, escape from spaces inside the armature 6 or 27 , the leadership body 9 or the yoke 5 respectively. 22 can be replenished.

A material that has been produced in a sintering process can only be used in such a way that the anchor 6 or 27 , the leadership body 9 and possibly also the yoke 5 or 22 only partially surrounded by porous material. Depending on the required pressure compensation and field of application, the coverage of the non-sintered parts must be selected.

1

magnet assembly

2

cup-shaped housing part

3

coil carrier

4

excitation coil

5

yoke

6

anchor

7

tappet

8th

The End

9

guide body (Cone)

10

flange of the yoke

11

recess

12

border area

13

armature space

14

shell

15

shoulder

16

Plastic compound

17

fastening lugs

18

metal reinforcement

19

plug

20

O-ring

21

magnet assembly

22

yoke

23

tappet

24

camp

25

bearing bush

26

thrust bearing

27

anchor

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 10238840 A1 [0002, 0025]
• - EP 1667177 A1 [0008, 0008]

Claims (9)

Switchable magnet arrangement ( 1 . 21 ) as an actuator or actuator for a valve or other functional elements with a magnetizable housing, an at least partially disposed in the magnetizable housing exciter coil ( 4 ), one upon energization of the exciting coil ( 4 ) axially in a bearing ( 24 ) movable anchor ( 6 . 27 ), one in the direction of actuation of the actuator directed, in a warehouse ( 26 ) guided axial plunger ( 7 . 23 ), one of the end faces of the housing final yoke ( 5 . 22 ) and a the other end of the housing final cone-shaped guide body ( 9 ), wherein the guide body ( 9 ) an axial passage for the plunger ( 7 . 23 ), characterized in that the armature ( 6 . 27 ) and / or the yoke ( 5 . 22 ) and / or the conical guide body ( 9 ) and / or the bearing ( 24 . 26 ) is at least surrounded by or surrounds a magnetically conductive, media-permeable material. Switchable magnet arrangement ( 1 . 21 ) according to claim 1, characterized in that the armature ( 6 . 27 ) and / or the yoke ( 5 . 22 ) and / or the conical guide body ( 9 ) and / or the bearing ( 24 . 26 ) consists of the magnetically conductive, media-permeable material. Switchable magnet arrangement ( 1 . 21 ) according to claim 1 or 2, characterized in that the magnetically conductive, media-permeable material is an open-pored, magnetically conductive, foam-like material. Switchable magnet arrangement ( 1 . 21 ) according to claim 3, characterized in that the open-pored material is sintered metal. Switchable magnet arrangement ( 1 . 21 ) according to one of claims 1 to 4, characterized in that the running surfaces of the armature ( 6 . 27 ) are mechanically processed. Switchable magnet arrangement ( 1 . 21 ) according to any one of claims 3 to 5, characterized in that the open-pored, magnetically conductive, foam-like material is a sintered, iron-containing, optionally mixed with other alloying elements material. Switchable magnet arrangement ( 1 . 21 ) according to one of claims 1 to 6, characterized in that the switchable magnet arrangement ( 1 . 21 ) is a proportional magnet. Switchable magnet arrangement ( 1 . 21 ) according to one of claims 1 to 7, characterized in that it is used as an actuator of a variable throttle for hydraulic, pneumatic and similar systems. Switchable magnet arrangement ( 1 . 21 ) according to one of claims 1 to 8, characterized in that it is used as a proportional magnet for camshaft adjustment.