EP1163687A1

EP1163687A1 - Electromagnet

Info

Publication number: EP1163687A1
Application number: EP01942784A
Authority: EP
Inventors: Heinz Leiber; Dirk Dünkel; Frank KÄHNY; Ralf Hecker; Stefan Masak
Original assignee: Tyco Electronics AMP GmbH
Current assignee: TE Connectivity Germany GmbH
Priority date: 2000-01-22
Filing date: 2001-01-18
Publication date: 2001-12-19
Anticipated expiration: 2021-01-18
Also published as: EP1163687B1; DE50103445D1; WO2001054146A1; DE10002628A1

Abstract

Disclosed is an electromagnet. The yoke of said electromagnet is comprised of lamellae. The stack of lamellae is arranged between two bearing plates. The end plates are connected by means of two yoke side plates. The armature is mounted inside the bearing plates.

Description

electromagnet

The invention relates to electromagnets with the features of the preamble of claim 1.

Yokes of magnetic circuits for electromagnets are screwed together or are positively locked together by beads in the metal sheets. This is the common technique, e.g. B. for ignition transformers. Most of these yokes are also encapsulated with plastic. The problem is the internal stress of thin sheets, which act like disc springs, and very difficult to achieve with a tight bond, in which each sheet lies in the bond without play, by bracing with screws.

In addition, in the case of a so-called deep magnet, that is to say, for example, a magnet with a pivotable armature and with an armature which is broad in the direction of the pivot axis and corresponding yokes, as described in DE 19854020.5, there is a high magnetic force. This leads to a certain deflection of the yoke. This will reinforced by the tensioning of the yoke by the external tensioning screws. These shape the plate pack in a fan shape, ie an expansion takes place on the side opposite the screws, which manifests itself as a yoke deflection. This creates different air gaps in the middle of the package from the outside. In order to enable a small holding current and a correspondingly low loss conduction, however, a small and even air gap should be achieved.

When using the electromagnet, e.g. B. in an actuator for driving a valve of an internal combustion engine, this must have not only high rigidity but also small dimensions in order not to unnecessarily enlarge the cylinder head. It must also be possible to adapt it to different valve distances. The weight must also be very small.

The invention is based on the object of achieving great stiffness with small deformations, with small dimensions and low weight. In addition, the magnets on the anchor must be easily adjustable.

This object is solved by the features of claim 1.

Sub-claims 2 to 11 contain configurations that further support the task solution.

Claims 12 to 26 describe an application of the invention to an actuator in which the invention has a particularly favorable effect. Here, the actuators must be stable on the cylinder head or an actuator Carrier or a tub can be attached to absorb the relatively high forces.

The stiffness is mainly achieved by the yoke stiffeners, which not only have to absorb the magnetic forces, but also the bearing forces and the supporting torque of the torsion bar on the bearing plate when the actuator is designed with a pivotable armature and use of a torsion spring. Small dimensions are achieved by relatively thin bearing plates, which are also advantageous for the coil connections described later. The decisive factor is the good non-positive and / or positive connection between the bearing plates and the yoke packs, since the yoke stiffeners through the yoke side plates divert the forces from the bearing plate into it, so that complex, thick bearing plates are prevented. The rigidity is achieved by appropriate coordination of the yoke package with the yoke stiffeners and an appropriate design of the bearing plates.

Claim 29 describes a method for the inexpensive manufacture of the electromagnet or the actuator.

Exemplary embodiments of the invention are explained with the aid of the drawing.

Show it:

Fig. 1 shows the structure of an actuator for driving a valve of an internal combustion engine in

Sectional view, in whose electromagnet the invention is used; Figure 2 shows the partially shown actuator in perspective.

Fig. 3 shows a partially alternative training.

4 shows a view of the armatures of two neighboring actuators;

5 shows one of the bearing plates;

6 shows a detail of FIGS. 4 and 5.

An electromagnetic actuator 1 for valve actuation of an internal combustion engine is partially shown in FIGS. 1 and 2. The actuator 1 has two electromagnets 2 and 3 consisting of two-pole yokes 2a and 3a and one winding 2b and 3b each. The electromagnets 2 and 3 work together with a lever 4 which is connected to an anchor tube 4a. This anchor tube 4a is pivotally mounted about an axis 5. Arranged in the interior of the anchor tube 4a is a torsion spring 6 in the form of a torsion bar, which is rigidly clamped at one end and is connected at its other end to the anchor tube 4a. The torsion bar 6 generates, for. B. both spring forces acting on the lever 4. The lever 4 carries an armature 7, which cooperates with the electromagnets 2 and 3 and generates the pivoting movement. The right end 4b of the lever 4 acts on a valve stem, not shown.

FIG. 2 shows that the yoke 2a is composed of lamellae 2a ^λ made of magnetic material. It is for

Improved clarity shown only part of the plate pack 2a. In practice, the entire space between the bearing plates 8 is filled with lamellae 2a ^Λ . In the bearing plates 8, the bearing of the lever 4 and thus the armature 7 is accommodated by means of the bearing tube 4a. The two bearing plates 8 are connected to one another by two yoke side plates 9 and 10, the side plates 9 and 10 being welded into the bearing plates 8. The lamellae 2a ^λ have small bulges 2a ^{λ λ} , via which they are suspended in the side plates 8, 9. The side plates 9 and 10 can be made of non-magnetic material and they can be electrically insulated from the slats 2a ^Λ by insulation 11. This isolation can also be done through an air gap. The side plate 10 is designed as a profile so that it can encompass the winding 2 b. The profile also increases the bending stiffness of the side plate 10 in the transverse direction. The two side plates 9 and 10 are attached to the upper end of the yoke, the bulge of which has little magnetic flux and thus also generates low eddy currents.

The electromagnet 2 is assembled in the following way: First, the side plates 9, 10 are only loosely connected to the bearing plates 8. The slats 2a are suspended in the side plates 9, 10. The armature is brought into the end position shown in FIG. 1 and the slats or the plate pack with the side plates are moved as a stable connection so that the slats rest directly on the armature 7 or lie with a predetermined small air gap to the armature 7. Now the yoke, e.g. B. pressed by magnetic force on the armature and in addition the two bearing plates 8 are pressed onto the disk pack 2a and then the side plates 9, 10 are connected to the bearing plates at 12, for. B. welded, soldered or caulked. If necessary, additional tension is generated on the side plates.

To connect the plate pack, the plates can have mutually fitting toothings and / or, for example, near the poles, eg. B. with 13 welds of the lamellae 2 to each other, and / or an overmolding of the plate pack can be provided. The lamellae are preferably welded to the side plates, the lamella packet being able to be pressed together beforehand with a defined force.

The electromagnet 3 can be assembled in an equivalent manner.

1 and 2 show that the entire actuator is arranged on common bearing plates 8. You can also extend the bearing plates 8 to the right and arrange a further actuator in these extensions of the bearing plates 8 in the same way, but rotated by 180 °, taking care to ensure that the lever ends 4b and the valves driven by them in the direction of the To move the paper plane against each other.

FIG. 3 shows an exemplary embodiment in which the left side plate 10 is designed as in FIGS. 1 and 2. In contrast, the right side plate 19 covers the side surface of the yoke 2a to a much greater extent than the side plate 9 of FIGS. 1 and 2. This side plate 19 is welded along its edges 20 to at least part of the slats 2a. This side plate can be made of non-magnetic material; with the exception of the welded edges 20, it can be electrically insulated from the lamellae 2a ^Λ . This can also be designed so that the side plate is inserted into the slats as shown in the right half of the picture. Again, the fins 2a ^Λ have the bulge 2a ^Λ to be able to attach to the slats. Alternatively, the side plate can be magnetically conductive and bear against the yoke without insulation, which supports the magnetic flux. At the ends, this side plate 19 is also connected to the bearing plates 8.

Fig. 4 shows a section through a double actuator, as indicated above. A laminated anchor 25 is shown in the upper half of the figure. This is connected to an anchor tube 21 shown in section, in which a torsion bar 22 extends. The bearing 23 and 23a of the anchor tube in the bearing plate are also shown. This bearing 23 and 23a can be realized by plain or roller bearings. On the left side, the torsion bar 22 is connected to the anchor tube 21 and on the right side to a torsion bar receptacle 24 fixed to the housing, which in turn is connected to a lever 24a, which acts as an extension, welded to the bearing plate 25 _r approximately at the center thereof at S. is. This welding enables precise adjustment of the torsion bar force by bringing the armature into the closed position of the valve shown in FIG. 2 and then turning the torsion bar lever 24a until the corresponding force is reached. The welding then takes place. It is advantageous to connect a hydraulic lash adjuster directly to the armature 25 and the pressure oil required for it, e.g. B. via a valve actuation lamella 25a of the armature 25 to the clearance compensation element (not shown) arranged between the armature and the valve. For this purpose, an oil connection 26 is necessary, which preferably connects the engine lubricating oil to a pressure line of a pump. pump is connected. So that the pressure oil does not emerge from the bearing 23a, a sealing element 26a is arranged behind this bearing. The pressure oil reaches the channel 27 in the valve actuation lamella 25a via the anchor tube 21. The valve actuation plate 25a is arranged off-center. The corresponding lamella of the neighboring actuator (under half of the figure) is labeled 25a ^λ . The distance between the fins 25a and 25a corresponds to the valve distance. The advantage of this arrangement can be seen from this, since it can be adapted to the valve distances in a wide range. The valve actuation plates 25 a and 25 a are embedded in the armature package.

The bearing bushes 28 are welded or soldered into the bearing plates 25 _L and 25 _r . This is done in a corresponding device for precise alignment. By means of angle pieces, of which the angle piece for the bearing plate 25 _{L is} shown in FIG. 6, the actuator is connected to the cylinder head 35 with screws 29. The bearing plates are relatively thin (about 1.5 to 2mm thick). The end slats are approx. 3mm thick, the other slats approx. 0.3mm.

The lower half of FIG. 4 shows the corresponding elements of the adjacent actuator. On the lower half of the figure, part of the anchor package 25 is cut away on the left and the plate package 30 of a yoke with a thicker end plate 31 is visible. The outer yoke reinforcement is effected by the side plate 32, which is welded to the bearing plate at S ₃ . The side plate 33 serves to reinforce the inner yoke. This corresponds to the structure shown in FIGS. 1 and 3. Here the inner reinforcement projects through the yoke side plate 33 the bearing plate 25 and is welded to it at S ₂ .

Fig. 5 shows a side view of the bearing plate 25 _L. 4 shows the view in the y direction shown. Here, the yoke side plates 32 and 33 are shown in dashed lines and dimensioned somewhat differently compared to FIGS. 1 and 2, and the implementation of the side plate 33 through a recess in the bearing plate 25 _L with the corresponding welding points S ₂ can also be seen. The torsion bar receptacle 24 and the lever 24a can also be seen here. The elements of the actuator adjacent to the parts 24 and 24a are arranged diagonally opposite one another on the bearing plate 25 _r . This means that the same parts can be used. The fastening screw 29 can also be seen. The coils 34 protrude through corresponding recesses in the bearing plates 25 _L and 25 _r . Their connections 34a are thus easily accessible for contacting the connecting cable. The yoke plate pack can also be screwed together with any additional welding or gluing or other connection options. The screw connections 37 and 37a shown on the left in FIG. 5 have the advantage of a simple adjustment. It can e.g. B. only the upper magnet can be screwed and the lower one welded.

It is also conceivable that the thicker yoke plates 31 z. B. for the two magnets below are connected in a kind of bridge to allow easier assembly and to achieve further stiffening of the bearing plates. The actuator of FIGS. 4 and 5 can also be embedded in the cylinder head 35 for better heat dissipation, as shown in FIG. 5 below, the installation Tolerances of the air gap can be compensated for by thermally conductive fillers. It is also conceivable to improve the heat dissipation for the upper magnets by using a heat conducting plate 36 which dissipates the heat from the top of the magnets to the cylinder head.

The bearing plates 25Lχ and 25 _r have to be non-magnetic or only weakly magnetic in order to produce only a small shunt, at least in the area of the armature. The material can be magnetic in the adjacent areas. The non-magnetic material, e.g. B. V2A costs a multiple of the magnetically conductive material. It is therefore conceivable to carry out a separation at 25 _LT in such a way that the middle part 25 _{LM is} non-magnetic and the adjacent part above 25 _L 0 and correspondingly below it is magnetic.

In order to generate good heat dissipation, the actuator should be mounted or adjusted flush with the bearing plates 25 _L and 25 _r .

5 and 6 show the fastening of the actuator by means of the fastening screw 29 on the cylinder head 35.

As an alternative to the screw 29, a shaft screw 29a can be used according to FIG. 6 with a hexagon at the upper end. This version has assembly advantages in terms of accessibility when mounting on the cylinder head.

Claims

claims

1) Electromagnet (2, 3) with an electrical one

Yoke (2a, 3a) having winding (2b, 3b) and an armature (7) opposite the poles of the yoke (2a, 3a), the yoke (2a, 3a) being composed of lamellae (2a) and means (8, 9, 10) are provided for holding the plate pack (2a) together, characterized in that the plate pack (2a) is arranged between end plates, in particular bearing plates (8), that these are provided by rigid side plates, in particular yoke side plates, running along the plate pack (2a) (9, 10) are connected to each other, and that the storage of the armature (7) is housed in the bearing plates (8).

2) Electromagnet according to claim 1, characterized in that the lamellae (2a ') have bulges (2a ^λ ) which allow the lamellae (2a ^λ ) to be suspended between the yoke side plates (9, 10).

3) Electromagnet according to one of claims 1 to 3, characterized in that bulges (2a ^{Λ λ} ) are provided in the vicinity of the end of the yoke (2a) facing away from the poles of the yoke (2a).

4) Electromagnet according to one of claims 1 to 3, characterized in that the connection through non-positive or positive joining process (e.g. welding, soldering, gluing, caulking or fitting).

5) Electromagnet according to one of claims 1 to 4, characterized in that the yoke side plates (8,

9) are made of non-magnetic material.

6) Electromagnet according to one of claims 1 to 5, characterized in that the yoke side plates (9,

10) are electrically insulated (11) with respect to the plate pack (2a).

7) Electromagnet according to one of claims 1 to 6, characterized in that at least one side plate (10) has a profile.

8) Electromagnet according to one of claims 1 to 7, characterized in that adjacent lamellae are connected to one another by a toothing (eg so-called punched packaging).

9) Electromagnet according to one of claims 1 to 8, characterized in that the lamellae (2a ^Λ ), in particular near the poles, are at least partially additionally connected to one another by welding or soldering (at 13).

10) Electromagnet according to one of claims 4 to 9, characterized in that the connection of the yoke side plates (9, 10) to the bearing plates (8) is carried out with tensioning of the disk pack (2a ^λ ). 11) Electromagnet according to one of claims 1 to 10, characterized by its use as part of an electromagnetic actuator (1), in which the armature (7) by magnetic force (2, 3) in conjunction with two oppositely directed spring forces (6) in two Is brought end positions and in which the armature movements in the two end positions is used to drive a valve of an internal combustion engine (via extension 4b).

12) Electromagnet according to one of the preceding claims, characterized in that at least one end of the side plates (9, 10) is connected to the corresponding end plate (8) by pressing together the disk pack (2a ^λ ) and the end plates (8).

13) Electromagnet according to one of the preceding claims, characterized in that in the bearing plates (8) the bearing of the lever (4) and thus the armature (7) is accommodated via its bearing tube (4a).

14) Actuator according to claim 11 to 13, characterized in that the yoke side plates (9, 10) of two electromagnets are attached to the bearing plates (8) and that this arrangement of the actuator constitutes an assembly unit.

15) Actuator according to claim 14, characterized in that the end plates (31) of the plate pack (30) are thicker in comparison to the other plates (factor 5 to 10) and are connected to the bearing plates (25 _r , 25 _L ) and that the bearing plates (25 _L , 25 _r ) are relatively thin (1, 5 to 2mm).

16) Actuator according to one of claims 11 to 15, characterized in that the armature (7) is pivotally mounted in the bearing plates (8) and a torsion spring (5) connected to the armature supplies at least part of the spring forces.

17) Actuator according to one of claims 11 to 16, characterized in that it forms, together with a further actuator, a unit which has bearing plates (25 _r , 25 _L ) common to both actuators, the actuators being opposite one another (Fig. 4, Fig. 5).

18) Actuator arrangement according to claim 17, characterized in that the opposing actuators have actuating elements for the valves attached to the armature eccentrically and are arranged rotated by 180 ° relative to one another (FIG. 4).

19) Actuator arrangement according to claim 17 or 18, characterized in that the common bearing plates

(25 _r , 25 _L ) are attached to a cylinder head or actuator bracket.

20) Actuator arrangement according to one of claims 17 to 19, characterized in that the bearing play is eliminated during the adjustment in that the bearing (4a) is preferably pressed in the direction of the magnet (2 and 3). 21) Actuator arrangement according to one of claims 18 to 20, characterized in that the two bearing plates (25 _r , 25 _L ) are connected to one another by screws (37, 37a).

22) Actuator arrangement according to Claim 21, characterized in that the yoke side plates (32, 33) are additionally connected (for example welded, glued, soldered) to the bearing plates (25 _r , 25 _L ).

23) Actuator arrangement according to one of claims 18 to 22, characterized in that the bushings (23) for mounting the armature (25) are positively and / or positively inserted into the bearing plates (25 _r , 25 _L ).

24) Actuator arrangement according to claim 23, characterized in that the bearing bushes (23) are arranged at least approximately on the center line of the bearing plates (25 _r , 25 _L ).

25) actuator arrangement according to one of claims 18 to

24, characterized in that for the adjustment of the torsion bar the armature is brought into at least one end position (e.g. resting on the magnet 2), that the torsion bar is pretensioned to a certain value by means of a lever (24a) and that the Lever (24a) is fixed (welded).

26) actuator arrangement according to one of claims 18 to

25, characterized in that the end plates (31) of two plate packs are at least partially connected to one another by a bridge. 27) Actuator arrangement according to one of claims 18 to 26, characterized in that the bearing plates (25 _r , 25 _L ) are composed of several partial plates (25 _LO , 25 _LM ), that one of the partial plates (25 _LM ) consists of largely non-magnetic material and that this partial plate (25 _LM ) is arranged in the area of the armature (25).

28) Actuator according to one of claims 18 to 27, characterized in that the bearing plates (25 _E , 25 _L ) are connected, in particular screwed, to an actuator carrier or the cylinder block (35) by means of an angle piece.

29) Method for producing an actuator arrangement, according to claims 18 to 27, characterized in that the armature (25) is brought into the end position near the poles, that the plate pack is adjusted to the armature (25) with a minimal air gap, so that the Lamella pack is pressed together and that the connections between the bearing plates (25 _r , 25 _L ) and the side plates (32, 39) are then preferably produced simultaneously on both sides.