Electromagnetic switching device and methods for its manufacture

Abstract

Electromagnetic switching device (10), with a magnetic armature (13), a pressure pin (19) movably guided in a bearing (21) along an axis (A), a yoke (16) and a bearing sleeve (11) which accommodates the bearing (21) and the magnetic armature (13), wherein an electromagnetic sheath (12) and the bearing sleeve (11) together, made of one material, are formed as a one-piece component (100), characterized in that the bearing sleeve (11) is closed on one side by a cover (23).

Description

[0001] The present invention relates to an electromagnetic switching device. More specifically, the invention relates to an electromagnetic switching device provided with a bearing sleeve that accommodates a magnet armature, a bearing, and a thrust pin guided over the bearing.

[0002] Furthermore, the invention relates to a method for producing an electromagnetic switching device. Background of the invention

[0003] In conventional electromagnetic switching devices, sealing is achieved, for example, by inserting O-ring seals or by overmolding the coil in a media-tight manner. A disadvantage of these prior art arrangements is that the additional components required result in increased assembly effort and thus higher costs. There is also the significant risk that fluctuations occurring during the overmolding process could lead to leaks.

[0004] DE 10 2006 015 233 B4 discloses an electromagnetic actuator in which the yoke section and the core section are realized as a single-piece yoke core element, eliminating the need for complex axial centering relative to each other. This creates a magnetic short circuit between the core and the yoke, which, due to additional geometric arrangements, has only a minor impact on efficiency, but does not completely reduce it. The bearing unit is mounted in the housing.

[0005] In DE 10 2007 061 862 A1, a bearing sleeve is integrated into the switchable magnet assembly using a welding process. All other parts are inserted into an injection mold and overmolded with plastic compound so that they are held firmly together. Pressure equalization in the magnet is to be achieved without compensating bores in the armature piston. For this purpose, it is proposed that the armature and / or the yoke and / or the conical guide body and / or the bearing be surrounded by a magnetically conductive, media-permeable material. Generic electromagnetic switching devices are disclosed in DE 22 55 272 A and US 2005 / 0 218 363 A1. DE 102 38 840 A1 shows another electromagnetic switching device.

[0006] The state-of-the-art devices therefore require increased assembly effort. Due to the overmolding process and the media-permeable material, complete and reliable sealing of the magnet from the environment cannot be achieved.

[0007] The object of the present invention is to provide an electromagnetic switching device which is simple and inexpensive to manufacture and yet has the required tightness with respect to the oil-wetted interior of the magnet and the environment.

[0008] This object is achieved by an electromagnetic switching device according to one of claims 1, 2, 3 or 4.

[0009] Another object of the invention is to provide a method for manufacturing an electromagnetic switching device which is simple and inexpensive.

[0010] The above object is achieved by a method for producing the electromagnetic switching device comprising the features of claim 6.

[0011] An electromagnetic switching device comprises at least one magnet armature, a yoke, a thrust pin movably guided in a bearing along an axis, and a bearing sleeve. The bearing sleeve accommodates at least the bearing and the magnet armature and, together with an electromagnet casing, forms a single-piece component.

[0012] According to claim 6, at least the electromagnet casing and the bearing sleeve are formed from a single material as a one-piece component by means of a forming process, preferably using deep-drawing technology. All other components still present in the electromagnetic switching device are inserted into the one-piece component, which comprises at least the electromagnet casing and the bearing sleeve. At least the magnet armature and the bearing, in which the pressure pin is guided along an axis, are inserted into the bearing sleeve. A coil, a coil carrier, an intermediate segment and, if appropriate, a pole core and / or a yoke are inserted between the electromagnet casing and the bearing sleeve. A sealing function is integrated into the bearing sleeve, thereby eliminating the need for additional components that form the sealing function. Furthermore, it is no longer necessary to overmold the components using an overmolding process.This reduces assembly effort and the risk of leaks that can occur during the overmolding process.

[0013] In a first embodiment of the invention, the bearing sleeve is closed at the end by a cover.

[0014] In a second embodiment of the electromagnetic switching device, the electromagnet casing, the bearing sleeve, and the pole core are formed as a single, integral component made of a single material. The pole core is formed on the outer diameter of the bearing sleeve. In this embodiment, the yoke is mounted as a separate component between the bearing sleeve and the electromagnet casing.

[0015] In a third embodiment of the electromagnetic switching device, the electromagnet casing, the bearing sleeve, the yoke, and the pole core are formed as a single, integral component made of a single material. The pole core and the yoke are formed on the outer diameter of the bearing sleeve. A yoke plate connects to the yoke formed on the bearing sleeve.

[0016] According to the fourth embodiment of the electromagnetic switching device, the one-piece component is deep-drawn.

[0017] The magnet armature can be mounted and / or guided inside the bearing sleeve. This can be achieved, for example, by a plain bearing provided between the magnet armature and the interior of the bearing sleeve. A magnetically non-conductive sliding layer can also be provided between the magnet armature and the interior of the bearing sleeve.

[0018] In a further embodiment of the electromagnetic switching device according to the invention, the electromagnet casing and the bearing sleeve are formed as a single, integral component made of a single material. The pole core and the yoke are mounted as separate components on the outer diameter of the bearing sleeve.

[0019] In the embodiments in which the pole core and / or yoke are mounted as separate components on the outer diameter of the bearing sleeve, these are preferably deep-drawn, extruded, machined or sintered.

[0020] The space of the magnet armature within the bearing sleeve is sealed at the bottom by pressing in flux guides. By creating a desired magnetic saturation at an intermediate segment located on the outer diameter of the bearing sleeve, the two flux guide segments, pole core and yoke, of the soft iron circuit are separated from each other.

[0021] The following exemplary embodiments will explain the invention and its advantages in more detail with reference to the accompanying figures. The proportions in the figures do not always correspond to the actual proportions, as some shapes are simplified and others are shown enlarged relative to other elements for better illustration. These show: Fig. 1 is a sectional view of an electromagnetic switching device according to the prior art, Fig. 2a is a sectional view of a first embodiment of the electromagnetic switching device, in which the electromagnet casing, bearing sleeve and pole core are formed as a single component, Fig. 2b a sectional view of the one-piece component according to the first embodiment, Fig. 2c a three-dimensional sectional view of the one-piece component according to the first embodiment, Fig. 3a is a sectional view of a second embodiment of the electromagnetic switching device, in which the electromagnet casing, bearing sleeve, pole core and yoke are formed as a single component, Fig. 3b a sectional view of the one-piece component according to the second embodiment, Fig. 3c a three-dimensional sectional view of the one-piece component according to the second embodiment, Fig. 4a a sectional view of a third embodiment of the electromagnetic switching device, in which the electromagnet casing and bearing sleeve are formed as a one-piece component and the pole core and yoke are separate components. Fig. 4b a sectional view of the one-piece component according to the third embodiment, Fig. 4c a sectional view and a three-dimensional view of the pole core, which is mounted as a separate component on the bearing sleeve.

[0022] Fig. 1 shows an electromagnetic switching device 10 according to the prior art. The bearing sleeve 11, which contains the magnet armature 13, is connected to the cup-shaped housing part 50 by welding and is thus a component of the electromagnetic switching device 10. The coil 14, coil carrier 15, and yoke 16 are arranged outside the bearing sleeve 11. The bearing sleeve 11, cup-shaped housing part 50, coil 14, coil carrier 15, and yoke 16 are inserted into an injection mold and overmolded with a plastic compound 52, so that they are fixed in their position in the electromagnetic switching device 10. The cup-shaped housing part 50 is closed by a conical guide body 51 in which a pressure pin 19 is guided. The pressure pin 19 is axially movable along an axis A.

[0023] Fig. 2a shows an electromagnetic switching device 10 according to the invention, according to a first embodiment. Fig. 2b and Fig. Figure 2c shows the one-piece component 100 manufactured from a single material by means of a forming process. This component consists of the electromagnet casing 12, the bearing sleeve 11, and the pole core 17. The pole core 17 is formed on the outer diameter 22 of the bearing sleeve 11. The coil 14, the coil carrier 15, the yoke 16, and an intermediate segment 18, by which the pole core 17 and the yoke 16 are separated from one another, are inserted between the bearing sleeve 11 and the electromagnet casing 12. The bearing 21, in which the pressure pin 19, which is movable along the axis A, is guided, and the movably mounted magnet armature 13, which is sealed by pressing in flux guides 40, are inserted into the interior 24 of the bearing sleeve 11. The bearing sleeve 11 is closed on one side by a cover 23, which is also formed by the forming process.

[0024] Fig. 3a shows an electromagnetic switching device 10 according to a second embodiment of the invention. Fig. 3b and Fig. Figure 3c shows the one-piece component 100 manufactured from a single material by means of a forming process. In this embodiment, the component consists of the electromagnet casing 12, the bearing sleeve 11, the pole core 17, and the yoke 16. The pole core 17 and the yoke 16 are formed on the outer diameter 22 of the bearing sleeve 11. Since the yoke 16 in this embodiment is formed directly on the outer diameter 22 of the bearing sleeve 11, the one-piece component 100 is closed at the upper end by a yoke plate 31. A bearing, advantageously a plain bearing 30, can also be provided in the bearing sleeve 11, which serves to support or guide the magnet armature 13. All other components still present in the magnetic switching device 10 are positioned as in the previous embodiment.

[0025] Fig. 4a shows an electromagnetic switching device 10 according to a third embodiment of the invention. Fig. Figure 4b shows the one-piece component 100, manufactured from a single material by means of a forming process. In this embodiment, the component consists of the electromagnet casing 12 and the bearing sleeve 11. Fig. Figure 4c shows the pole core 17, which in this embodiment is mounted as a separate component on the outer diameter 22 of the bearing sleeve 11. All other components still present in the magnetic switching device 10 are positioned as in the previous embodiments. List of reference symbols 10 electromagnetic switching device 11 Bearing sleeve 12 Electromagnet casing 13 Magnet armature 14 coil 15 coil carriers 16 yoke 17 pole cores 18 Intermediate segment 19 Push pin 21 camps 22 outer diameter 23 lids 24 Inside the bearing sleeve 30 plain bearings 31 yoke plate 40 River guide 50 pot-shaped housing part 51 conical guide body 52 plastic compound 100 one-piece component A axis

Claims

[1] Electromagnetic switching device (10), with a magnetic armature (13), a pressure pin (19) movably guided in a bearing (21) along an axis (A), a yoke (16) and a bearing sleeve (11) which accommodates the bearing (21) and the magnet armature (13), wherein an electromagnet casing (12) and the bearing sleeve (11) are formed together from one material as a one-piece component (100), characterized by that the bearing sleeve (11) is closed on one side by a cover (23). [2] Electromagnetic switching device (10) according to the preamble of claim 1, wherein a conical pole core (17) is formed on the bearing sleeve (11) from the material of the electromagnet casing (12) and the bearing sleeve (11), characterized by that the yoke (16) is mounted on the outer diameter of the bearing sleeve (11). [3] Electromagnetic switching device (10) according to the preamble of claim 1, wherein a conical pole core (17) and a conical yoke (16) on the bearing sleeve (11) are formed from the material of the electromagnet casing (12) and the bearing sleeve (11). [4] Electromagnetic switching device (10) according to the preamble of claim 1, characterized by that the one-piece component (100) is deep-drawn. [5] Electromagnetic switching device (10) according to the preamble of claim 2, wherein the pole core (17) and the yoke (16) are separated from each other by a magnetically saturated intermediate segment (18). [6] A method for manufacturing an electromagnetic switching device (10), comprising the following steps, - forming a one-piece component (100) from a material by means of deep drawing, wherein the one-piece component (100) comprises at least one bearing sleeve (11) and an electromagnet casing (12); - inserting a magnet armature (13), a pressure pin (19) and a bearing (21) into the bearing sleeve (11); and - Inserting a coil (14) with coil carrier (15) and a yoke (16) between the bearing sleeve (11) and the electromagnet casing (12) of the one-piece component (100). [7] Method according to claim 6, wherein a pole core (17) is formed on the bearing sleeve (11) during deep drawing of the one-piece component (100). [8] Method according to claim 6, wherein during deep drawing of the one-piece component (100) a pole core (17) and a yoke (16) are formed on the bearing sleeve (11).

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