Electromechanical brake with transmission housing as extrusion

Abstract

The invention relates to an electromechanical brake (10) for a motor vehicle. The electromechanical brake (10) comprises an electric motor (14) which rotationally drives a spindle drive unit (38) arranged in a caliper housing (50) by means of a transmission (26) such that a brake actuator (62) for applying a braking force can be axially adjusted. According to the invention, the transmission (26) is arranged in a transmission housing (18) separate from the caliper housing (50), which transmission housing is connected to the caliper housing (50), the transmission housing (18) being designed as a pressure element.

Description

TECHNICAL FIELD

[0001] The invention relates to an electromechanical brake for a motor vehicle. The invention furthermore relates to a motor vehicle having such an electromechanical brake. BACKGROUND

[0002] Service brakes are generally brakes with which a brake piston together with brake pads is pressed onto a brake disc by brake fluid in order to brake a vehicle. In the course of the increasing electrification of assemblies in motor vehicles, service brakes should also be configured as electromechanical brakes, so that the brake fluid and the complex valve and line structure associated therewith can be dispensed with. By means of such electromechanical brakes, maintenance costs can also be significantly reduced.

[0003] The document WO 2020 / 230000 A1 describes an electromechanical disc brake which has a brake caliper housing in which a pressure device is arranged which applies a pre-load to the brake pads. The pressure device comprises a screw drive unit having a screw spindle and an axially movable screw nut. The screw nut is here connected to a speed reduction transmission. Furthermore, an angular contact ball bearing is provided which rotatably supports the screw nut and takes up the axial forces of the screw nut.

[0004] The document EP 1 030 979 B1 discloses an electromechanical brake device for braking a motor vehicle wheel. The brake device has a brake caliper in which an electric motor is arranged. The electric motor drives a screw drive unit by means of which brake pads arranged on brake caliper jaws of the brake caliper can be brought to bear against a brake disc in order to brake.

[0005] Although electromechanical brakes are widely known in the prior art, there is still an ongoing effort to provide an electromechanical brake which is lighter in weight and less expensive to manufacture than competing electromechanical brakes. For example, the economic efficiency of an electromechanical brake can be improved in such a way that material costs are reduced, the number of parts is reduced, the parts are easier to manufacture or the electromechanical brake is easier to assemble. SUMMARY

[0006] The invention is based on the object of providing an electromechanical brake for a motor vehicle which can be manufactured more easily and more economically.

[0007] This object is achieved by an electromechanical brake having the subject matter of claim 1. Preferred embodiments result from the dependent claims.

[0008] The invention provides an electromechanical brake for a motor vehicle. The electromechanical brake comprises an electric motor, which rotates a screw drive unit arranged in a brake caliper housing via a transmission, so that a brake adjuster for applying a brake force can be adjusted axially. The transmission is arranged in a transmission housing separate from the brake caliper housing, which is connected to the brake caliper housing, wherein the transmission housing is configured as an extruded part.

[0009] According to the invention, the brake caliper housing and the transmission housing are configured as separate housings, which are connected to one another in the assembled state. Accordingly, the brake caliper housing and the transmission housing can also be formed by different manufacturing processes. According to the invention, the transmission housing is configured as an extruded part. The housing is thus manufactured by extrusion. This manufacturing process has the advantage that the transmission housing can be manufactured in a single manufacturing step. In order to be able to manufacture the transmission housing by means of extrusion, the transmission housing is correspondingly adapted. The manufacture of the housing can thus be faster and more convenient. Accordingly, the transmission housing and thus the entire electromechanical brake can be manufactured more economically.

[0010] In a preferred embodiment of the invention, the transmission housing is formed from an aluminum material. The use of an aluminum material for the transmission housing has the advantage that this material is easily processed by extrusion. Furthermore, aluminum has a low weight, so that the weight of the electromechanical brake can be reduced. Since aluminum has a high thermal conductivity, the heat generated during the long-term use of the electromechanical brake can be better dissipated outward.

[0011] In another preferred embodiment of the invention, the transmission housing has a machined region. This machining can be carried out here, for example, by milling or turning. By means of the machining, unnecessary material of the transmission housing can be removed here, so that the weight of the transmission housing can additionally be reduced.

[0012] Preferably, the transmission housing is configured on the outside with a retaining geometry, by means of which a mounting can be fastened to the transmission housing. By forming this retaining geometry from extrusion, the retaining geometry can be formed in the same manufacturing step as the transmission housing. Thus, the retaining geometry can be formed without additional costs. Advantageously, the retaining geometry can be used to fasten a mounting, so that, for example, a cable can be more conveniently fixed to the transmission housing.

[0013] In an advantageous improvement, the transmission housing is constructed with mounting surfaces for the electric motor and / or for a control unit that controls the electric motor. These mounting surfaces allow the electric motor and control unit to be secured to the transmission housing without additional components. This eliminates the need for components used to secure the electric motor to the transmission housing. The mounting surfaces also provide sufficient area for the electric motor and control unit to abut. Consequently, the manufacturing cost of these additional components can be reduced, allowing for more economical manufacturing of the electromechanical brake.

[0014] Advantageously, the interface between the transmission housing and the brake caliper housing is circular. The interface is understood here as the area where the two housings connect to each other. Because the interface is circular, the position of the transmission housing relative to the brake caliper housing is not fixed. Accordingly, the transmission housing can rotate relative to the brake caliper housing before being fastened to it. Therefore, the position of the transmission housing relative to the brake caliper housing can be flexibly selected according to the available mounting space. This eliminates the need for additional variations with different angles between the transmission housing and the brake caliper housing. Consequently, this electromechanical brake can be manufactured more economically and used more flexibly.

[0015] The present invention also provides a motor vehicle having such an electromechanical brake. This motor vehicle can achieve the advantages and features described above. Attached Figure Description

[0016] Embodiments of the invention are illustrated in the accompanying drawings and described in more detail below. Wherein:

[0017] Figure 1 A longitudinal cross-sectional view of an electromechanical brake according to an embodiment of the present invention is shown;

[0018] Figure 2 A perspective view of an embodiment of the transmission device housing is shown;

[0019] Figure 3 A side view of an electromechanical brake according to an embodiment is shown; and

[0020] Figure 4 A perspective view of the transmission device housing according to an embodiment is shown. Detailed Implementation

[0021] Figure 1A longitudinal sectional view of an electromechanical brake 10 according to an embodiment of the present invention is shown. The electromechanical brake 10 includes an electric motor 14 disposed outside a transmission housing 18 of the electromechanical brake 10. The electric motor 14 drives a transmission device 26 disposed in the transmission housing 18 via a motor shaft 22. The transmission device 26 is formed by a worm (not shown here) constructed on the motor shaft 22, which meshes with a worm wheel 30. The worm wheel 30 is non-rotatably fastened to a lead screw 34 of a lead screw drive unit 38. Thus, the lead screw 34 can be rotated by the worm wheel 30. The electromechanical brake 10 additionally has an angular contact ball bearing 42 by which the lead screw 34 is rotatably supported.

[0022] A pinion 46 is additionally arranged at the axial end of the lead screw 34, through which a parking brake function can be formed. The transmission housing 18 is connected to a brake caliper housing 50, which is separate from the transmission housing 18. According to the invention, the transmission housing 18 is constructed as an extrusion. This makes it easier to manufacture the transmission housing. The brake caliper housing 50 is connected to the brake caliper jaws 54 of the electromechanical brake 10. A lead screw drive unit 38, configured here as a ball screw drive, is arranged in the brake caliper housing 50. By rotating the lead screw 34, the lead screw nut 58 of the lead screw drive unit 38, and thus the brake adjuster 62 arranged at the lead screw nut 58, can be axially displaced. To prevent rotation of the lead screw nut 58, the lead screw nut has radial anti-rotation tabs 66 that engage with an anti-rotation groove 70.

[0023] Figure 2 A perspective view of an embodiment of the transmission housing 18 is shown. As can be seen in the figure, a retaining geometry 74 is constructed on the transmission housing 18, by which the mounting member can be fastened to the transmission housing 18. This retaining geometry 74 can also be conveniently formed by extrusion. Furthermore, a control unit 82 (see [reference]) is constructed on the transmission housing 18. Figure 3 The transmission housing 18 has a mounting surface 78a for the motor shaft 22 and a mounting surface 78b for the electric motor 14. The transmission housing 18 is additionally provided with a hole 86 for the motor shaft 22. This hole 86 is introduced into the transmission housing 18 through a manufacturing step following extrusion.

[0024] Figure 3 A side view of an electromechanical brake 10 according to an embodiment of the present invention is shown. In this figure, a control unit 82 is fastened to a mounting surface 78a. It is also shown that the transmission housing 18 has a machined area 90 after extrusion, thereby reducing the weight of the transmission housing 18. The mounting surfaces 78a, 78b and the machined area 90 are also... Figure 4As shown in the figure, the interface 94 between the transmission housing 18 and the brake caliper housing 50 is circular. Therefore, the transmission housing 18, and consequently the control unit 82 and the electric motor 14, can rotate relative to the brake caliper housing 50 according to space requirements.

Claims

1. An electromechanical brake (10) for a motor vehicle, the electromechanical brake comprising an electric motor (14) that drives a screw drive unit (38) arranged in a brake caliper housing (50) via a transmission device (26) to rotate, such that a brake adjuster (62) for applying braking force can be axially adjusted. Its features are, The transmission device (26) is arranged in a transmission device housing (18) that is separate from the brake caliper housing (50) and connected to the brake caliper housing (50), wherein the transmission device housing (18) is configured as an extrusion.

2. The electromechanical brake (10) according to claim 1, characterized in that, The housing (18) of the transmission device is made of aluminum.

3. The electromechanical brake (10) according to claim 1 or 2, characterized in that, The housing (18) of the transmission device has a machined area (90).

4. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, The transmission housing (18) has a retaining geometry (74) on its outer side, through which the mounting component can be fastened to the transmission housing (18).

5. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, The transmission housing (18) is provided with a mounting surface (78b) for the electric motor (14) and / or a mounting surface (78a) for the control unit (82) for controlling the electric motor (14).

6. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, The interface (94) between the transmission housing (18) and the brake caliper housing (50) is circular.

7. A motor vehicle, said motor vehicle comprising an electromechanical brake (10) according to any one of the preceding claims.

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