Electromechanical brake

Abstract

To provide an electromechanical brake for a motor vehicle.SOLUTION: An electromechanical brake has an electric motor, and the electric motor drives a spindle drive device through a transmission device unit, and a brake controller may move in an axial direction to brake through the spindle drive device. Further, a drive device housing which receives at least the transmission device unit and the spindle drive device is provided. The drive device housing is provided separately from a brake caliper for holding a brake disc and is connected to the brake caliper. The drive device housing is formed by two housing portions connected to each other. At least the transmission device unit is disposed in a first housing portion, and at least the spindle drive device is disposed in a second housing portion.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Generally, service brakes are brakes that brake a vehicle by pressing a brake piston together with brake linings against a brake disc via brake fluid. In contrast, parking brakes are configured as electromechanical brakes. As more and more devices in a vehicle are electrified, service brakes should also be configured as electromechanical brakes, thereby eliminating brake fluid and the associated expensive valve and piping structures. Likewise, such electromechanical brakes can significantly reduce maintenance costs.

[0003] Patent Document 1 discloses an electromechanical brake device for braking automobile wheels. The brake device has a brake caliper in which an electric motor is arranged. The electric motor drives a spindle drive, and via the spindle drive, brake linings arranged on the brake gripping portion of the brake caliper can abut against a brake disc for braking.

[0004] Patent Document 2 discloses an electromechanically operable brake that presses a brake lining against a brake disc for braking. The brake includes a spindle drive with a spindle and a spindle nut, the spindle connected to the brake lining. The spindle nut is rigidly connected to a sleeve that surrounds the spindle nut from the outside. The sleeve is rotatably arranged in a brake caliper via a bearing. A permanent magnet is arranged in the sleeve, forming the rotor of an electric motor. The sleeve is surrounded by a stator, which can drive the rotor. By correspondingly rotating the spindle nut, the brake lining can be moved axially to apply a braking force. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] European Patent No. 1030979 [Patent Document 2] European Patent No. 0944781 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION It is an object of the present invention to provide an electromechanical brake for a motor vehicle that is economical to manufacture and has low weight. [Means for solving the problem]

[0007] This problem is solved by an electromechanical brake having the subject matter of claim 1. Preferred embodiments are set forth in the dependent claims.

[0008] The present invention provides an electromechanical brake for a motor vehicle. The electromechanical brake includes an electric motor that drives a spindle drive via a transmission unit, via which a brake controller is axially movable for braking. A drive housing is provided that receives at least the transmission unit and the spindle drive. The drive housing is provided as a separate part from and connected to a brake caliper that grips a brake disc. The drive housing is formed by two interconnected housing parts, with at least the transmission unit arranged in the first housing part and at least the spindle drive arranged in the second housing part.

[0009] The part of the electromechanical brake that acts on the brake lining or that applies braking force to the brake disc may be interpreted as a brake controller. The part of the electromechanical brake that grips the brake disc like pliers may be interpreted as a brake caliper. According to the present invention, the drive housing and the brake caliper are provided as separate parts that can be connected to each other. Therefore, the brake caliper and the drive housing may be formed from different materials. Typically, the brake caliper is formed from a heavy cast material so that it can withstand high braking forces. In this case, the brake caliper is manufactured by a casting process. By separating the brake caliper and the drive housing, the drive housing can be manufactured from a lighter material, and the formation of the brake caliper is simplified during the casting process. This also allows the drive housing to be formed by a more economical manufacturing method compared to the casting process.

[0010] According to the present invention, the drive housing is additionally divided into two separate housing sections. In this case, the two separate sections of the drive housing can be configured according to their loads. The housing section containing the spindle drive is typically designed to receive braking forces and therefore must have greater strength. In contrast, the first housing section is designed to receive the transmission unit. This means that the first housing section is not subjected to braking forces. This allows the first housing section to be significantly thinner than the second housing section, thereby reducing the weight of the electromechanical brake. Similarly, the electromechanical brake can be manufactured more economically, since less material is required to form it. Furthermore, the divided drive housing has the advantage that the individual housing sections can be manufactured more easily.

[0011] According to a preferred embodiment of the invention, the first and second housing parts are made of different materials. In particular, the second housing part is made of a harder material than the first housing part. A lighter and less expensive material can be used for the first housing part, corresponding to lower loads. This further reduces the weight of the electromechanical brake, thereby improving the driving comfort of electromechanical brakes arranged on unsprung vehicle wheels.

[0012] According to another preferred embodiment of the invention, the first housing part is formed by deep drawing, stamping and / or bending. This manufacturing method has the advantage that it is inexpensive to carry out. Machining steps can also be partially or completely omitted. This allows the first housing part to be produced economically in large quantities.

[0013] In a preferred embodiment, the first housing part is joined to the second housing part via shrink fitting, slip fitting, welding, gluing, and / or brazing. This type of joining allows the two housing parts to be joined together quickly, easily, and inexpensively. In particular, no additional fastening means are required to fasten the first housing part to the second housing part. Furthermore, joining the two housing parts in this way has the advantage that dimensional tolerances can be compensated for by sliding the two housing parts relative to each other. This allows the electromechanical brake to be manufactured more precisely.

[0014] In a preferred variant, the second housing part is rotationally symmetrical, with the exception of the anti-rotation slot for the spindle drive. By designing the component rotationally symmetrically, it can be manufactured more economically, and therefore requires less machining volume. This also allows the second housing part to be manufactured more quickly.

[0015] In a preferred embodiment, the first housing part forms the connection surfaces for the electric motor and the control unit, which allows the electric motor and the control unit to be mounted directly to the first housing part. Therefore, no additional parts are required to fasten the control unit and the electric motor to the first housing part. This simplifies the fastening of the control unit and the electric motor.

[0016] According to another preferred embodiment, the first housing part is made up of at least two parts, which are arranged radially opposite one another in the drive housing. Radial can be interpreted as being radial to the extension direction of the drive housing. In other words, the two housing parts are arranged side by side, not one after the other, in the axial direction. The two housing parts are thus connected to the second housing part. Having the first housing part made up of at least two parts offers the advantage, compared to a one-part design, that each housing part can be deep-drawn in the radial direction. This allows for the formation of other radially formed components that cannot be formed in the axial deep-draw direction. This simplifies the production of the first housing part, and does not require subsequent attachment of other components to the housing, for example, via welding.

[0017] According to a preferred configuration, the two parts of the first housing part are joined to one another by welding, gluing and / or brazing. By joining the two parts of the first housing part in this way, fastening means, such as a screw connection, can be dispensed with. Additionally, the joining of the two parts can be simplified.

[0018] According to another preferred embodiment, one of the two parts of the two-part first housing part forms a bearing receptacle for the transmission unit. A bearing for the drive shaft of the transmission unit can be arranged in this bearing receptacle. This improves the bearing support of the drive shaft in the first housing part. By forming the bearing receptacle in the first housing part, the subsequent fixing of this bearing receptacle is eliminated. This allows the first housing part to be manufactured economically.

[0019] Preferably, each section of the two-part first housing section is deep-drawn in a radial direction. In this case, the radial direction is determined by the extension direction of the drive housing or the rotation axis of the spindle drive. The deep-drawing tool then deep-draws the sections of the first housing section in a radial direction relative to this rotation axis or extension direction, depending on the mounting position of each section. This allows corresponding radially oriented components to be formed in the sections of the first housing section. This allows for an improved first housing section to be constructed.

[0020] The present invention additionally provides a motor vehicle having such an electromechanical brake, which has the advantages and features described above. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a cross-sectional view of an electromechanical brake according to one embodiment of the present invention. [Figure 2] 2 is a cross-sectional view of first and second housing portions of a drive housing according to one embodiment of the present invention. FIG. [Figure 3] 1 is a perspective view of a first housing portion according to a first embodiment of the present invention; FIG. [Figure 4] FIG. 10 is a plan view of a first housing portion according to another embodiment of the present invention. [Figure 5] FIG. 2 is a perspective view of a first portion of the first housing section. [Figure 6] FIG. 10 is a perspective view of a second portion of the first housing portion. DETAILED DESCRIPTION OF THE INVENTION

[0022] Several embodiments of the invention are shown in the drawings and are described in detail below.

[0023] 1 shows a cross-sectional view of an electromechanical brake 10 according to one embodiment of the present invention. The electromechanical brake 10 has a drive housing 14 connected to a brake caliper 18, which grips a brake disc 22. The drive housing 14 protrudes through a brake caliper opening 26 and is fixed to the brake caliper 18 via a threaded connection 34 in the region of an inner side 30 of the brake caliper 18. The drive housing 14 forms a step 38 that abuts an outer side 42 of the brake caliper 18.

[0024] The drive housing 14 comprises a first housing part 46 and a second housing part 50, which are connected to one another and arranged axially opposite one another. The second housing part 50 is connected to the brake caliper 18. A transmission unit 54 is arranged in the first housing part 46 and is formed by a worm 62 and a worm gear 66, which are driven by an electric motor 58. A spindle drive 70 is arranged in the second housing part 50 and, in the illustrated embodiment, is configured as a ball screw transmission.

[0025] The spindle drive 70 has a spindle 74 that extends into the first housing part 46 so that the worm gear 66 can be fixed to one end of the spindle 74. The spindle drive 70 is therefore driven via the worm gear 66. The spindle drive 70 additionally has a spindle nut 78, at the axial end of which a brake controller 82 is arranged, and the brake controller 82 is axially movable together with the spindle nut 78. This allows the brake controller 82 to slide toward the brake disc 22. To receive the axial force, an angular contact ball bearing 86 is arranged in the second housing part 50, and the angular contact ball bearing 86 interacts with a spindle shoulder 90.

[0026] FIG. 2 shows a cross-sectional view of the first and second housing portions 46, 50 of the drive housing 14 according to one embodiment of the present invention. As shown in the drawing, the second housing portion 50 has an axially oriented anti-rotation slot 94 for locking the spindle nut 78 against rotation. Additionally, the second housing portion 50 is shown to be rotationally symmetrical, excluding the anti-rotation slot 94. This simplifies the manufacture of the second housing portion 50. The first housing portion 46 has a fastening opening 98 through which the electric motor 58 can be fastened. Additionally, a shaft opening 102 is formed in the first housing portion 46, through which the drive shaft of the worm 62 extending from the electric motor 58 projects. A contact opening 106 is also provided, through which the electric motor contacts can be introduced into the electric motor 58.

[0027] 3 shows a perspective view of the first housing part 46 according to one embodiment of the present invention. This view also shows the various openings 98, 102, 106 in the first housing part 46. The first housing part 46 further defines a connection surface 110 for the electric motor 58 and a connection surface 114 for the control unit. This eliminates the need for additional parts to secure the electric motor 58 and the control unit to the first housing part 46.

[0028] FIG. 4 shows a plan view of a first housing portion 46 according to another embodiment of the present invention. This embodiment differs from the embodiments shown in the previous figures in that the first housing portion 46 is formed not from one piece but from two pieces 46a, 46b. The two pieces 46a, 46b of the first housing portion 46 abut one another radially, as viewed in the extension direction of the drive housing 14. As a result, each piece 46a, 46b also abuts the second housing portion 50. Due to this configuration of the first housing portion 46, the first housing portion 46 does not need to be formed as a whole. Rather, each piece 46a, 46b of the first housing portion 46 is formed separately. Unlike the previous embodiment, in which the first housing portion 46 is formed axially by a deep drawing process, each piece 46a, 46b of the first housing portion 46 can be formed radially by a deep drawing process.

[0029] FIG. 5 shows a perspective view of the first part 46a of the first housing part 46. This part 46a, like the first housing part 46 of the previous embodiment, also forms the contact opening 106. The first part 46a forms a bearing receptacle 118, in particular for the drive shaft of the worm 62. A bearing is arranged in the bearing receptacle 118, and one end of the drive shaft is supported by this bearing. Such a component can be formed by a radial deep drawing step. An additional work step for providing such a bearing receptacle 118 can be omitted compared to the embodiment of FIGS. 1 to 3.

[0030] 6 shows a perspective view of the second portion 46b of the first housing part 46. This portion 46b may also be fabricated by a radial deep drawing step. This second portion 46b forms the stationary opening 98, the axial opening 102, and the contact openings 106, as previously described with respect to FIGS. 2 and 3. [Explanation of symbols]

[0031] 10 Electromechanical brake 14 Drive unit housing 18 Brake caliper 22 Brake disc 26 Brake caliper opening 30 Inside 34 Threaded Connection 38 Step section 42 Outside 46 first housing part 46a First Part 46b Second part 50 second housing part 54 Transmission unit 58 Electric motor 62 Warm 66 Worm Gear 70 Spindle drive unit 78 Spindle nut 82 Brake controller 86 Angular contact ball bearing 90 Spindle step 94 Anti-rotation slit 98 Fixed aperture 102 shaft opening 106 Contact opening 110 Connection surfaces for electric motors 114 Connection surface for control unit 118 Bearing housing

Claims

1. 1. An electromechanical brake (10) for a motor vehicle, comprising an electric motor (58) which drives a spindle drive (70) via a transmission unit (54), via which a brake controller (82) is axially movable for braking, and a drive housing (14) for receiving at least the transmission unit (54) and the spindle drive (70), 1. An electromechanical brake (10) comprising: a drive housing (14) provided as a separate part from, and connected to, a brake caliper (18) that grips a brake disc (22); the drive housing (14) being formed by two interconnected housing parts (46, 50), with at least the transmission unit (54) arranged in the first housing part (46) and at least the spindle drive (70) arranged in the second housing part (50).

2. The electromechanical brake (10) of claim 1, wherein said first and second housing portions (46, 50) are formed from different materials.

3. 3. The electromechanical brake (10) according to claim 1 or 2, characterized in that the first housing part (46) is formed by deep drawing, stamping and / or bending.

4. 4. The electromechanical brake (10) according to claim 1, wherein the first housing part (46) is joined to the second housing part (50) via shrink fitting, slip fitting, welding, gluing and / or brazing.

5. 5. The electromechanical brake (10) according to claim 1, wherein the second housing part (50) is rotationally symmetrical with the exception of a rotation prevention slot (94) for the spindle drive (70).

6. 6. The electromechanical brake (10) according to claim 1, wherein the first housing part (46) forms connection surfaces (110, 114) for an electric motor (58) and a control unit.

7. 7. The electromechanical brake (10) according to claim 1, wherein the first housing part (46) is made up of at least two parts (46a, 46b), the two parts (46a, 46b) being arranged radially opposite each other in the drive housing (14).

8. 8. The electromechanical brake (10) according to claim 7, characterized in that the two parts (46a, 46b) of the first housing part (46) are joined to each other via welding, gluing and / or brazing.

9. 9. An electromechanical brake (10) according to claim 7 or 8, characterized in that one of the two parts (46a) of the first housing part (46) consisting of two parts forms a bearing receptacle (118) for the transmission unit (54).

10. 10. The electromechanical brake (10) according to any one of claims 7 to 9, characterized in that each part (46a, 46b) of the two-part first housing part (46) is radially deep-drawn.

11. A motor vehicle comprising an electromechanical brake (10) according to any one of claims 1 to 10.

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