Electromechanical brake with motor housing manufactured by cup extrusion process

Abstract

The invention relates to an electromechanical brake with a motor housing manufactured by a cup extrusion process, the electromechanical brake (10) for a motor vehicle and comprising an electric motor (18) which drives a spindle drive unit (50) arranged in a brake caliper housing (22) in rotation, so that a brake adjuster (66) is movable in an axial direction (62) of the brake caliper housing (22) for applying a brake force. A motor housing (14) arranged at the brake caliper housing (22) accommodates the electric motor (18), and a controller housing (78) of a controller (82) controlling the electric motor (18) is arranged at the motor housing (14). The motor housing (14) is made of a metallic material, which forms a cup-shaped accommodation cavity (70) in which the electric motor (18) is accommodated. The motor housing (14) is closed by the controller housing (78), and the motor housing (14) is formed by a cup extrusion process.

Description

Technical Field

[0001] The present invention relates to an electromechanical brake for a motor vehicle and a motor vehicle having such an electromechanical brake. Background Technology

[0002] Service brakes are typically used to brake a vehicle by pressing the brake piston and brake pads against the brake disc via brake fluid. With the increasing electrification of assemblies in motor vehicles, service brakes should also be designed as electromechanical brakes, eliminating the need for brake fluid and its associated complex valve and piping systems. Such electromechanical brakes also significantly reduce maintenance costs.

[0003] Document WO 2023 / 166434 A1 describes a brake caliper for a disc brake. The caliper includes a caliper housing, on which a transmission housing is disposed. A controller housing is mounted on the back side of the transmission housing, and within the controller housing are housed an electric motor and a brake controller that controls the electric motor.

[0004] Document DE 10 2009 046 044 B4 describes an electromechanically operable disc brake for a motor vehicle. This electromechanically operable disc brake includes a caliper housing surrounding a brake disc. The caliper housing has a shell-shaped recess in which an electric motor for the brake is arranged. A transmission is arranged above the electric motor and the caliper housing, via which a main shaft drive unit arranged in the caliper housing is driven. Above the transmission is a circuit carrier for a control unit, via which the electric motor can be controlled. The circuit carrier and the transmission are sealed externally by a cover plate. Summary of the Invention

[0005] The object of the present invention is to provide an electromechanical brake for motor vehicles that can be manufactured more simply and economically, and that is better resistant to environmental factors such as dust and moisture.

[0006] This objective is achieved by an electromechanical brake having the subject matter of claim 1. Preferred embodiments can be derived from the dependent claims.

[0007] This invention proposes an electromechanical brake for motor vehicles. The electromechanical brake includes an electric motor that rotatably drives a main shaft drive unit arranged in a brake caliper housing, such that a brake adjuster can move axially along the brake caliper housing to apply braking force. A motor housing located in the brake caliper housing houses the electric motor, and a controller housing for controlling the electric motor is arranged in the motor housing. The motor housing is made of a metallic material and forms a cup-shaped receiving cavity in which the electric motor is received. The motor housing is closed by the controller housing and is formed by a cup-shaped stamping process.

[0008] A cup-shaped receiving cavity refers to a cavity that is open only at one axial end. According to the invention, the motor housing only needs to prevent the intrusion of dust and moisture at this axial end. This reduces the number of parts requiring sealing. At this axial end, the motor housing is closed by the controller housing. Therefore, a separate cover plate is not required to close the motor housing. This reduces the number of parts and the weight of the electromechanical brake. To further reduce weight, the motor housing is preferably made of aluminum.

[0009] In the cup-shaped part stamping process, the workpiece blank is cold-formed into the desired shape between the mattize and the punch. Therefore, no waste in the form of chips is generated during the manufacturing of the motor housing. This allows for more economical manufacturing of motor housings. Furthermore, this cup-shaped part stamping process achieves high dimensional and shape accuracy, thus typically eliminating the need for post-processing. Compared to machining, this process allows for higher throughput in the same amount of time when manufacturing motor housings. This also makes the manufacturing of motor housings more economical.

[0010] In a preferred embodiment of the invention, the motor housing is formed by a cup-shaped forward extrusion process. In this process, the material flow direction is the same as the punch movement direction. Compared to a cup-shaped transverse extrusion process, the cup-shaped forward extrusion process offers the advantage of a favorable microstructural orientation for the motor housing.

[0011] In an alternative embodiment of the invention, the motor housing is formed by a cup-shaped reverse extrusion process. In this process, the material flow direction is opposite to the punch movement direction. Compared to a cup-shaped transverse extrusion process, the cup-shaped reverse extrusion process offers the advantage of a favorable microstructural orientation for the motor housing.

[0012] In another alternative embodiment, the motor housing is formed by a cup-shaped transverse stamping process. In this process, the material flow direction is oriented transversely to the punch movement direction. This stamping process allows for advantageous microstructure orientations for specific applications.

[0013] In a favorable improvement, a seal is arranged between the edge of the receiving cavity and the controller housing. This seal between the controller housing and the edge of the receiving cavity also better prevents dust and moisture from entering the receiving cavity.

[0014] Advantageously, the seal is a wet seal. The advantage of a wet seal is that liquid does not accumulate in the sealing area in front of the seal, thus making it more robust in terms of preventing leakage compared to a solid seal.

[0015] In another advantageous embodiment, the seal is a resilient solid seal. The advantage of a solid seal is that no surface pretreatment, such as laser cleaning or plasma cleaning, is required before applying the silicone.

[0016] According to a suitable implementation, the edges of the receiving cavity are machined. For example, this machining can provide a receiving portion for a sealing part. Furthermore, the height of the edge can be adjusted by machining according to the size of the electric motor used. Therefore, only one type of motor housing is needed for electric motors of different sizes. Thus, only one die and one punch are required to form different motor housings. Because the manufacturing cost of such dies and punches is relatively high, motor housings of different sizes can also be manufactured economically.

[0017] According to another suitable embodiment, the housing not only houses the electric motor but also the parking brake device. The parking brake device secures the electromechanical brake in the braking position. Thus, even when the motor is off, the vehicle remains stationary in a power-deprived state. Since the parking brake device is housed within the housing, a separate housing for the parking brake device is eliminated. This reduces the number of parts required for the mechanical brake.

[0018] The present invention also proposes a motor vehicle having such an electromechanical brake. The aforementioned advantages and characteristics can all be achieved through such a motor vehicle. Attached Figure Description

[0019] Embodiments of the present invention are shown in the accompanying drawings and explained in more detail in the following description. Wherein:

[0020] Figure 1 A cross-sectional view of an electromechanical brake according to an embodiment of the present invention is shown; and

[0021] Figure 2 A cross-sectional view of the motor housing according to the present invention is shown. Detailed Implementation

[0022] Figure 1A cross-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 18 disposed in a motor housing 14. The motor housing 14 is disposed here at a brake caliper housing 22 of the electromechanical brake 10. The electromechanical brake 10 also includes a brake caliper portion 26 that spans across a brake disc 30 and is connected to the brake caliper housing 22. The electric motor 18 includes a worm gear 38 disposed at a motor shaft 34 that extends into the brake caliper housing 22 and drives a worm wheel 42. The worm wheel 42 is disposed at a main shaft 46 of a main shaft drive unit 50 disposed in the brake caliper housing 22. Thus, the main shaft 46 is rotatably driven. The main shaft 46 is rotatably supported in the brake caliper housing 22 by a bearing 54. By rotating the main shaft 46, the main shaft nut 58 of the main shaft drive unit 50 can be moved in the axial direction 62.

[0023] In the illustrated embodiment, the spindle drive unit 50 is configured as a ball screw drive. A brake adjuster 66 is arranged at the spindle nut 58; in this embodiment, the brake adjuster is configured as a brake bushing. By moving the spindle nut 58 and the brake bushing 66, the brake bushing can be brought into contact with the brake disc 30 to perform braking.

[0024] Figure 2 A cross-sectional view of a motor housing 14 according to the invention is shown. The motor housing 14 is made of a metallic material to form a cup-shaped receiving cavity 70 in which an electric motor 18 is housed. The motor housing 14 is manufactured by a cup-shaped stamping process. This manufacturing process significantly reduces the amount of waste in the form of chips compared to cutting the motor housing 14. The motor housing 14 is open at one axial end, allowing the electric motor 18 to be installed through this end. In the illustrated embodiment, in addition to the electric motor 18, a parking brake device 74 is also arranged in the receiving cavity 70. This eliminates the need for a separate housing for the parking brake device 74.

[0025] The motor housing 14 is closed at its open axial end by a controller housing 78, in which a controller 82 for controlling the electric motor 18 is arranged. Therefore, the motor housing 14 does not require a separate cover for closure. Additionally, the amount of wiring work between the electric motor 18 and the controller 82, and between the controller 82 and the parking brake device 74, can also be reduced. A seal 86 is provided between the controller housing 78 and the motor housing 14 to prevent dust and moisture from entering the receiving cavity 70. The seal 86 is located in a groove 94 formed by the edge 90 of the motor housing 14.

Claims

1. An electromechanical brake (10) for a motor vehicle, the electromechanical brake comprising an electric motor (18) that rotatably drives a main shaft drive unit (50) arranged in a brake caliper housing (22), such that a brake adjuster (66) is movable along the axial direction (62) of the brake caliper housing (22) to apply braking force, wherein, A motor housing (14) disposed at the brake caliper housing (22) accommodates the electric motor (18), and a controller housing (78) for controlling the electric motor (18) is disposed at the motor housing (14). The motor housing (14) is characterized in that it is made of metal material and forms a cup-shaped receiving cavity (70) in which the electric motor (18) is accommodated. The motor housing (14) is closed by the controller housing (78), and the motor housing (14) is formed by a cup-shaped stamping process.

2. The electromechanical brake (10) according to claim 1, characterized in that, The motor housing (14) is formed by a cup-shaped forward extrusion process.

3. The electromechanical brake (10) according to claim 1, characterized in that, The motor housing (14) is formed by a cup-shaped reverse stamping process.

4. The electromechanical brake (10) according to claim 1, characterized in that, The motor housing (14) is formed by a cup-shaped part transverse stamping process.

5. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, A sealing portion (86) is arranged between the edge (90) of the receiving cavity (70) and the controller housing (78).

6. The electromechanical brake (10) according to claim 5, characterized in that, The sealing part (86) is a wet sealing part.

7. The electromechanical brake (10) according to claim 5, characterized in that, The sealing part (86) is an elastic solid sealing part.

8. The electromechanical brake (10) according to any one of claims 5 to 7, characterized in that, The edges (90) of the receiving cavity (70) are machined.

9. The electromechanical brake (10) according to any one of the preceding claims, characterized in that, In addition to accommodating the electric motor (18), the cavity (70) also accommodates the parking brake device (74).

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

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