Electromechanical brake

Abstract

The invention relates to an electromechanical brake (10) for a motor vehicle. The electromechanical brake (10) comprises an electric motor (54) which drives a spindle drive unit (34) arranged in a brake caliper housing (22) such that a brake actuator (38) can be moved axially, wherein a control unit (68) is provided by means of which the electric motor (54) can be controlled. The electric motor (54) is arranged coaxially with the spindle drive unit (34), and part of the control unit (68) extends from a control device housing (66) into the brake caliper housing (22) or into an electric motor housing (50) which accommodates the electric motor (54).

Description

[0001] Description

[0002] Title:

[0003] Electromechanical brake

[0004] The present invention relates to an electromechanical brake for a motor vehicle and a motor vehicle which has such an electromechanical brake.

[0005] State of the art

[0006] The service brake is typically a brake that uses brake fluid to press a brake piston and brake pad against a brake disc to slow the vehicle. The parking brake, on the other hand, is an electromechanical brake. With the increasing electrification of vehicle components, the service brake is also being considered for electromechanical brakes, thus eliminating the need for brake fluid and the associated complex valve and line system. Such an electromechanical brake could also significantly reduce maintenance requirements.

[0007] EP 1 030 979 B1 discloses an electromechanical braking device for braking a motor vehicle wheel. The braking device has a brake caliper in which an electric motor is arranged. The electric motor drives a spindle drive unit, via which brake pads arranged on a brake caliper of the brake caliper can be applied to a brake disc for braking.

[0008] German patent application DE 10 2018 211 443 A1 discloses a pressure generating device for a vehicle's braking system. US patent application 2019 / 0003535 A1 relates to a clamp for a brake unit for overlapping the outer surface of a tension disc in a cabin, comprising an electric motor driving a rotating shaft, a first continuous screw meshed with a first primary gear, and a second continuous screw meshed with a second primary gear.

[0009] The object underlying the invention is to provide an electromechanical brake for a motor vehicle which requires less installation space.

[0010] The problem is solved by an electromechanical brake for a motor vehicle according to claim 1. Preferred embodiments are described in the dependent claims.

[0011] Disclosure of the invention

[0012] The invention discloses an electromechanical brake for a motor vehicle. The electromechanical brake comprises an electric motor which drives a spindle drive unit arranged in a brake caliper housing, so that a brake lever is axially movable, and a control unit is provided by which the electric motor can be controlled. The electric motor is arranged coaxially with the spindle drive unit, and part of the control unit extends from a control unit housing into the brake caliper housing or into an electric motor housing that accommodates the electric motor.

[0013] A brake divider is a component that applies a braking force to a brake disc. The brake divider can, for example, include a brake pad. By coaxially arranging the electric motor with the spindle drive unit, a worm gear between the motor shaft and the spindle drive unit can be omitted, since the direction of rotation is also coaxial with the direction of rotation of the spindle drive unit. Furthermore, the installation space can be reduced in the radial direction. According to the invention, part of the control unit is thus provided in both the control unit housing and the brake caliper housing or the electric motor housing. This allows for better utilization of the available space in the brake caliper housing or the electric motor housing, and the size of the control unit housing can be reduced. An electromechanical brake designed in this way therefore requires less installation space.

[0014] In a preferred embodiment of the invention, the control unit extends between the electric motor and the spindle drive unit. This part of the control unit does not extend between the electric motor and a housing. As a result, the control unit housing can be mounted centrally on the brake caliper housing or the electric motor housing, so that the control unit housing does not extend beyond the end of the control unit housing. This allows the axial length of the electromechanical brake to be kept short, thus requiring minimal installation space.

[0015] In a further preferred embodiment of the invention, part of the control unit extends into the area of ​​a motor shaft bearing. This part of the control unit is thus arranged at the same axial position as the motor shaft bearing of the electromechanical brake. Since the radial dimensions of such a bearing are relatively small, the available installation space can be used for this part of the control unit. Therefore, the axial length of the electromechanical brake does not need to be increased to accommodate this part of the control unit. By such an arrangement, the installation space required for the electromechanical brake can thus be reduced.

[0016] Preferably, the control unit housing is arranged radially inwards on the brake caliper housing or electric motor housing, relative to the brake disc being braked. The control unit housing thus faces a wheel axle of the vehicle. Since the brake caliper is located on a radially outer edge of the brake disc, the wheel rim is situated radially above the brake caliper. Therefore, there is usually very little installation space above the brake caliper to accommodate the control unit housing. By appropriately orienting the control unit housing, the unused space radially below the brake caliper can be utilized. Such an arrangement allows for optimal use of the available installation space.

[0017] In a further advantageous design, the control unit housing is attached to the brake caliper housing or electric motor housing using an adhesive. This eliminates the need for fasteners such as screws. Similarly, no mounting points, such as eyelets, are required on the control unit housing for attachment. Consequently, this method of attaching the control unit housing reduces the weight of the electromechanical brake. Furthermore, the design of the control unit housing is simplified, as mounting points are no longer necessary. This results in a lighter and more economical electromechanical brake.

[0018] Advantageously, the part of the control unit that protrudes into the brake caliper housing or electric motor housing includes at least one printed circuit board (PCB). Thus, at least one PCB of the control unit extends into the brake caliper housing or electric motor housing. The electrical components of the control unit are arranged on this PCB. Due to the large number of electrical components, the PCB has large dimensions, which typically determine the size of the control unit housing. By arranging at least part of the PCB within the brake caliper housing or electric motor housing, the control unit housing can therefore be made smaller. Consequently, the installation space required for such an electromechanical brake can be reduced.

[0019] In a further advantageous embodiment, the circuit board extends into the brake caliper housing or electric motor housing in such a way that a position sensor mounted on the circuit board, for detecting the position of the electric motor rotor, is positioned in the area of ​​a position sensing disk. The position sensor is thus mounted directly on the circuit board. This eliminates the need for wiring between the position sensor and the circuit board. Detecting the rotor's position is therefore easily accomplished. This allows for the provision of an electromechanical brake that is simpler to manufacture and requires less installation space.

[0020] According to a practical embodiment, a connector receptacle is formed on the control unit housing. This receptacle is located on a side of the control unit housing aligned axially with the spindle drive unit, with the side facing away from the spindle drive unit. In other words, the side with the connector receptacle points axially towards the spindle drive unit. However, the side does not point towards the spindle drive unit, but away from it. Thus, the side points towards the interior of the vehicle. Consequently, a cable coming from inside the vehicle can be more easily connected to the connector receptacle.

[0021] The invention further specifies a motor vehicle which has such an electromechanical brake. Such a motor vehicle has the properties and advantages described above.

[0022] Exemplary embodiments of the invention are shown in the drawing and explained in more detail in the following description. It shows:

[0023] Figure 1 Sectional view of an electromechanical brake after a

[0024] Exemplary embodiment of the invention, and

[0025] Figure 2 Rear view of the electromechanical brake from Figure 1.

[0026] Figure 1 shows a sectional view of an electromechanical brake 10 according to an embodiment of the invention. The electromechanical brake 10 comprises a brake caliper 14 which surrounds a brake disc 18. The electromechanical brake 10 also includes a brake caliper housing 22, which in the embodiment shown here is formed in multiple parts. The brake caliper housing 22 is formed by a bore 26 in the brake caliper 14 and by a housing part 30 attached to the brake caliper 14. A spindle drive unit 34 is arranged in the brake caliper housing 22, which axially displaces a brake lever 38 for braking.

[0027] The brake caliper housing 22 additionally incorporates a spindle drive bearing 42 for the spindle drive unit 34 and a planetary gear 46. The housing part 30 of the brake caliper housing 22 is surrounded by an electric motor housing 50, which, like the housing part 30, is attached to the brake caliper 14. An electric motor 54 is arranged between the housing part 30 and the electric motor housing 50, which drives a motor shaft 62 connected to a sun gear 58 of the planetary gear 46. The electric motor 54 is arranged coaxially with the spindle drive unit 34. A control unit housing 66, for receiving a control unit 68, is attached to the electric motor housing 50 by means of an adhesive. The control unit housing 66 is mounted radially inwards on the electric motor housing 50.

[0028] A printed circuit board 70 is arranged in the control unit housing 66, extending from the control unit housing 66 into the electric motor housing 50. The printed circuit board 70 is thus positioned in both the control unit housing 66 and the electric motor housing 50. In the illustrated embodiment, the printed circuit board 70 extends in the area of ​​a bearing 74 of the motor shaft 62. Since the bearing 74 of the motor shaft 62 has only a small outer diameter, no additional height is required for the printed circuit board. The printed circuit board 70 is arranged between the electric motor 54 and the spindle drive unit 34.

[0029] In the embodiment shown here, a position sensing disk 78 is additionally attached to the motor shaft 62 between the circuit board 70 and the electric motor 54. Accordingly, the circuit board 70 extends below the position sensing disk 78. To detect the position of a rotor 82 of the electric motor 54, a position sensor 86 is arranged on the circuit board 70 in the area below the position sensing disk 78. This eliminates the need for wiring between the position sensor 86 and the circuit board 70.

[0030] Figure 2 shows a rear view of the electromechanical brake 10 from Figure 1. The brake caliper 14 and the electric motor housing 50 attached to the brake caliper 14 are visible in this figure. The brake disc 18, shown with dashed lines, is also shown. This figure shows that the control unit housing 66 is mounted on the electric motor housing 50, oriented radially inwards with respect to the brake disc 18. This allows the control unit housing 66 to utilize a radially inner area adjacent to the electric motor housing 50.

[0031] A connector receptacle 90 is provided on one side 88 of the control unit housing 66 for a connector, via which the control unit 68 can be connected to a vehicle bus. The connector receptacle 90 is aligned axially with the electric motor 54 or the spindle drive unit 34. Additionally, the connector receptacle 90 points away from the electric motor 54 and the spindle drive unit 34. This simplifies and saves space when making electrical contact with the control unit 68.

Claims

Claims 1. Electromechanical brake (10) for a motor vehicle comprising an electric motor (54) which drives a spindle drive unit (34) arranged in a brake caliper housing (22) so that a brake divider (38) is axially movable, wherein a control unit (68) is provided by which the electric motor (54) can be controlled, characterized in that the electric motor (54) is arranged coaxially with the spindle drive unit (34) and a part of the control unit (68) extends from a control unit housing (66) into the brake caliper housing (22) or into an electric motor housing (50) accommodating the electric motor (54).

2. Electromechanical brake (10) according to claim 1 , characterized in that the part of the control unit (68) extends between the electric motor (54) and the spindle drive unit (34).

3. Electromechanical brake (10) according to claim 1 or 2, characterized in that the part of the control unit (68) extends in the area of ​​a bearing (74) of a motor shaft (62).

4. Electromechanical brake (10) according to one of the preceding claims, characterized in that the control unit housing (66) is arranged radially inwards on the brake caliper housing (22) or electric motor housing (50) with respect to a brake disc (18) to be braked.

5. Electromechanical brake (10) according to one of the preceding claims, characterized in that the control unit housing (66) is attached to the brake caliper housing (22) or electric motor housing (50) by means of an adhesive.

6. Electromechanical brake (10) according to one of the preceding claims, characterized in that the brake caliper housing (22) or Electric motor housing (50) protruding part of the control unit (68), comprising at least one circuit board (70).

7. Electromechanical brake (10) according to claim 6, characterized in that the circuit board (70) extends into the brake caliper housing (22) or electric motor housing (50) such that a position sensor (86) arranged on the circuit board (70) for detecting a position of a rotor (82) of the electric motor (54) is positioned in the area of ​​a position sensing disk (78).

8. Electromechanical brake (10) according to one of the preceding claims, characterized in that a plug receptacle (90) is formed on the control unit housing (66), which is arranged on a side (88) of the control unit housing (66) oriented in the axial direction of the spindle drive unit (34), wherein the side (88) is facing away from the spindle drive unit (34).

9. Motor vehicle comprising an electromechanical brake (10) according to any of the preceding claims.

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