Actuating device for brake system

Abstract

The invention relates to an actuating device (1) for a brake system (2), comprising: an electric motor (21), the rotor (22) of which is arranged in a rotationally fixed manner on a rotatably mounted drive shaft (23); a movably mounted pressure element (3); and a transmission device (26) by means of which the drive shaft (23) is operatively connected to the pressure element (3), the transmission device (26) having a movable threaded spindle (27), the anti-rotation element (35) being connected to the threaded spindle (27) in a rotationally fixed manner, and the anti-rotation element (35) being connected to the threaded spindle (27) in a rotationally fixed manner. The anti-rotation element (27) interacts with a housing (7) of the actuating device (1) and / or with an element of the actuating device (1) arranged fixedly relative to the housing in order to form an anti-rotation portion (44) for the threaded spindle (27). It is provided that the rotationally fixed connection of the anti-rotation element (35) to the threaded spindle (27) is formed by a form-fitting connection (36).

Description

Technical Field

[0001] The present invention relates to an operating device for a brake system, the operating device comprising: an electric motor, wherein a rotor of the electric motor is non-rotatably arranged on a rotatably supported drive shaft; a movably supported pressure element; and a transmission device, via which the drive shaft is effectively connected to the pressure element, wherein the transmission device has a movable threaded spindle, wherein an anti-rotation element is non-rotatably connected to the threaded spindle, and wherein the anti-rotation element interacts with a housing of the operating device and / or with an element of the operating device fixedly arranged relative to the housing to form an anti-rotation portion for the threaded spindle.

[0002] The invention also relates to a braking system. Background Art

[0003] The hydraulic brake system of a motor vehicle usually has a plurality of friction brake devices. The friction brake device is operatively connected to an operating device of the brake system so that the friction brake device can be operated by the operating device. With the increasing degree of electrification of motor vehicles, the operating devices of the brake system are also increasingly electrified. In this regard, it is known that the operating device for the brake system is equipped with an electric motor, wherein the rotor of the electric motor is arranged non-rotatably on a rotatably supported drive shaft. In order to enable the friction brake device to be operated by the operating device, the operating device also has a movably supported pressure element. The drive shaft is operatively connected to the pressure element via a transmission. Therefore, the transmission is configured to convert the rotation of the drive shaft into a translational movement of the pressure element. For this purpose, the transmission usually has a movable threaded spindle. In order to prevent the threaded spindle from rotating during the operation of the operating device, an anti-rotation element is usually non-rotatably connected to the threaded spindle. The anti-rotation element interacts with the housing of the operating device and / or with an element of the operating device that is arranged fixedly relative to the housing to form an anti-rotation portion for the threaded spindle. In previously known actuating devices, the anti-rotation element is usually welded to the threaded spindle, so that the rotationally fixed connection of the anti-rotation element to the threaded spindle is formed by a material connection. Summary of the invention

[0004] The actuating device according to the invention with the features of claim 1 has the advantage that the actuating device can be realized cost-effectively. To this end, it is provided according to the invention that the non-rotatable connection of the anti-rotation element to the threaded spindle is formed by a form-fit connection. When assembling the actuating device, the form-fit connection can be formed more easily than the aforementioned material connection, thereby reducing the assembly work. The manufacturing costs of the actuating device can thus be reduced. In addition, since the threaded spindle and the anti-rotation element do not have to be spatially accessible to a welding machine, the assembly of the actuating device is also facilitated. In particular, the non-rotatable connection of the anti-rotation element to the threaded spindle is formed only by plugging the two elements together. Preferably, the anti-rotation element is arranged on the threaded spindle in a non-rotatable manner. According to a preferred embodiment, the transmission device has a spindle transmission mechanism, wherein the spindle transmission mechanism has a threaded spindle. According to an alternative embodiment, the transmission device preferably has a ball screw transmission, wherein the ball screw transmission has a threaded spindle. Preferably, the threaded spindle is coupled to the pressure element in such a way that the pressure element can be moved by the threaded spindle. As an alternative to this, the threaded spindle preferably forms the pressure element.

[0005] According to a preferred embodiment, the form-fit connection is formed by at least one radially protruding joint. A mechanically stable form-fit connection can be achieved by such a joint. In this case, the joint protrudes radially inwards or radially outwards, for example. Preferably, the threaded spindle and the anti-rotation element each have at least one radially protruding joint, wherein the joints interact with each other to form an anti-rotation device.

[0006] According to a preferred embodiment, the engagement toothing of the anti-rotation element meshes with the engagement toothing of the threaded spindle to form a positive connection. The engagement toothing has a plurality of toothed engagement portions arranged one after the other in the circumferential direction. The engagement toothing can achieve a particularly mechanically stable positive connection. In particular, it is achieved that during operation of the operating device, the torque transmitted from the threaded spindle to the anti-rotation element acts on the anti-rotation element in a uniformly distributed manner in the circumferential direction of the anti-rotation element.

[0007] According to a preferred embodiment, the anti-rotation element is made of plastic. By making the anti-rotation element from plastic, even complex geometries, such as joints, or more precisely, joint teeth, can be easily produced. In particular, the anti-rotation element is made of plastic by an injection molding process. Particularly preferably, the anti-rotation element is made of glass-fiber reinforced plastic. This material has a high strength, so that the anti-rotation element can be designed to be relatively small or slim. This saves material costs and installation space.

[0008] Preferably, the anti-rotation element is made of a metal material. Metal materials also have high strength, so that the anti-rotation element can be implemented relatively small, thus saving material costs and structural space. Particularly preferably, the anti-rotation element is made of steel. Preferably, the anti-rotation element is made of a metal material by a cold forming process (for example by cold stamping).

[0009] According to a preferred embodiment, the anti-rotation element is constructed in a skeletonized manner by means of grooves. In particular, when the anti-rotation element is made of glass fiber reinforced plastic or of a metal material, a large design of the anti-rotation element is not necessary in terms of sufficient mechanical strength. Therefore, the material costs can also be reduced by providing the grooves.

[0010] Preferably, the threaded spindle is manufactured by a cold forming process. The necessary structural parts of the threaded spindle, such as the thread or the engagement part, more precisely the engagement toothing, of the threaded spindle can be manufactured simultaneously by the cold forming process without the need for subsequent processing steps. This has the effect that the manufacturing costs of the threaded spindle can be reduced. Alternatively, the threaded spindle is only partially manufactured by a cold forming process. For example, a blank of the threaded spindle is first manufactured by a cold forming process. Then, the thread and / or the engagement part, more precisely the engagement toothing, are formed by a processing manufacturing process, such as impact or rolling.

[0011] According to a preferred embodiment, it is provided that the anti-rotation element is connected to the threaded spindle in an axially fixed manner with reference to the displacement axis of the threaded spindle. As a result, the fixing of the anti-rotation element to the threaded spindle is particularly mechanically stable, and the threaded spindle can be easily handled together with the anti-rotation element as a pre-assembled part, for example when assembling the actuating device. According to an alternative embodiment, it is preferably provided that the anti-rotation element has axial play relative to the threaded spindle.

[0012] According to a preferred embodiment, it is provided that the threaded spindle or the anti-rotation element has an undercut or an undercut portion, into which the anti-rotation element or the threaded spindle engages, so that the anti-rotation element is connected to the threaded spindle in an axially fixed manner. By engaging the anti-rotation element or the threaded spindle, in particular radially, in the undercut or the undercut portion, a mechanically stable, axially fixed connection of the anti-rotation element to the threaded spindle is achieved. Preferably, the undercut or the undercut portion extends over the entire circumference in the circumferential direction on the threaded spindle or the anti-rotation element. Such an undercut or such an undercut portion can be easily realized technically.

[0013] According to a preferred embodiment, the anti-rotation element is connected to the threaded spindle in an axially fixed manner by caulking the anti-rotation element and / or by caulking the threaded spindle. The anti-rotation element and / or the threaded spindle are thus formed by caulking so that the anti-rotation element is connected to the threaded spindle in an axially fixed manner. This allows a mechanically particularly stable force-transmitting connection and / or a form-fitting connection to be achieved. Preferably, the anti-rotation element is deformed by caulking so that it engages particularly radially in an undercut or undercut of the threaded spindle. Alternatively or additionally, the threaded spindle is preferably deformed by caulking so that it engages particularly radially in an undercut or undercut of the anti-rotation element.

[0014] According to a preferred embodiment, it is provided that the threaded spindle has a first end section facing the pressure element, and the anti-rotation element is arranged at this first end section. The first end section is easily accessible for the arrangement of the anti-rotation element, so that the arrangement at the first end section is preferred. The arrangement of the anti-rotation element at the first end section also brings the following advantages: the position of the first end section in the radial direction is particularly accurately defined, which is advantageous for the reliable transmission of axial forces from the threaded spindle to the pressure element.

[0015] According to a preferred embodiment, the anti-rotation element has an annular section and the threaded spindle is inserted into a channel in the annular section. This advantageously enables a positive connection between the anti-rotation element and the threaded spindle. Preferably, the inner side of the anti-rotation element, which forms the channel, has a toothing of the anti-rotation element for this purpose. Preferably, the outer side of the threaded spindle, which is arranged radially opposite to the inner side, has a toothing of the threaded spindle. Preferably, at least one of the aforementioned grooves is formed in the annular section. Particularly preferably, the annular section has at least one annular groove and / or at least one groove in the shape of an annular section.

[0016] Preferably, the anti-rotation element has at least one radial protrusion which radially engages in a radial recess of the housing of the operating device to form the anti-rotation portion. Thus, the anti-rotation element interacts with the housing of the operating device to form the anti-rotation portion. A particularly reliable anti-rotation portion is thereby formed. Preferably, the anti-rotation element has a plurality of radial protrusions which radially engage in corresponding other radial recesses of the housing to form the anti-rotation portion. Particularly preferably, the anti-rotation element has two radial protrusions which are arranged to be offset by 180° in the circumferential direction of the anti-rotation element. Preferably, at least one of the aforementioned grooves is formed in the radial protrusion. Particularly preferably, the radial protrusion has one or more prismatic grooves.

[0017] Preferably, a sliding pad is arranged on the radial projection. The sliding pad brings about a low-friction guidance of the radial projection in the radial recess.

[0018] Preferably, the housing is a cylindrical extruded profile. Extruded profiles can generally be produced cost-effectively, so that by constructing the housing as an extruded profile, the manufacturing costs of the operating device are also reduced. The element of the cylindrical construction has a side wall that is at least substantially closed in the circumferential direction, wherein the side wall forms or surrounds the axial channel of the cylindrical element. Correspondingly, the cylindrical extruded profile also has such a side wall and such an axial channel, wherein the axial channel forms the interior of the housing of the extruded profile. However, the term "cylindrical" does not mean a cross-section with a specific shape. On the contrary, the cross-section of the extruded profile can have different shapes. However, the axial channel preferably has a cross-section that is at least substantially circular. The extruded profile is preferably made of aluminum. Constructing the housing as an extruded profile also provides the following advantages: the above-mentioned radial recess can be realized without the need for additional processing steps, and the radial protrusion of the anti-rotation element radially engages in the radial recess. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be explained in more detail below with reference to the accompanying drawings, wherein:

[0020] Figure 1 A cross-sectional view showing an operating device of a brake system;

[0021] Figure 2 Another cross-sectional view of the operating device is shown;

[0022] Figure 3 A cross-sectional view showing a transmission of a manipulation device; and

[0023] Figure 4 A top view of the anti-rotation element of the actuating device is shown. DETAILED DESCRIPTION

[0024] Figure 1 The longitudinal section of an actuating device 1 for a brake system 2 (not shown in detail) of a motor vehicle is shown. The actuating device 1 has a movably mounted pressure element 3, which in the present case is designed as a push rod 3. The pressure element 3 can be moved along a displacement axis 4 in a first direction 5 and in a second direction 6 opposite to the first direction 5. The displacement axis 4 corresponds to the longitudinal center axis of the pressure element 3.

[0025] The pressure element 3 is arranged at least partially in a housing 7 of the actuating device 1. In the present case, the housing 7 is a cylindrical extruded profile 7. In this respect, the housing 7 has a side wall 8 which is closed in the circumferential direction. The side wall 8 forms or surrounds an axial channel 9 of the housing 7, wherein the axial channel 9 forms a housing interior 10 of the housing 7. In the present case, the axial channel 9 has a circular cross section. The pressure element 3 is arranged in the housing 7, more precisely in the housing interior 10, so that the displacement axis 4 is oriented perpendicular to the cross section of the housing 7.

[0026] The master brake cylinder 11 of the actuating device 1 is arranged fixedly on the housing 7 relative to the housing. In the present case, the master brake cylinder 11 is arranged at the first end side 12 of the side wall 8. A first hydraulic piston 13 and a second hydraulic piston 14 are supported in the master brake cylinder 11 so as to be movably supported, that is, so as to be movably supported in the first direction 5 and the second direction 6. The master brake cylinder 11 has a plurality of hydraulic couplings 15, 16. If the actuating device 1 is installed in the brake system 2 as intended, the hydraulic couplings 15, 16 are fluidically connected to the slave cylinders of the friction brake device of the brake system 2. In this case, the friction brake device can be actuated by moving the hydraulic pistons 13 and 14 in the first direction 5. The pressure element 3 is coupled to the hydraulic pistons 13 and 14 so that the hydraulic pistons 13 and 14 can be moved in the first direction 5 by the pressure element 3. Therefore, the friction brake device can be actuated by moving the pressure element 3.

[0027] A housing plate 17 is also arranged fixedly relative to the housing 7. In the present case, the housing plate 17 is arranged at a second end face 18 of the side wall 8 facing away from the first end face 12. The housing plate 17 at least partially closes the axial channel 9.

[0028] The operating device 1 also has a drive unit 19. Figure 2 The embodiment of the drive unit 19 is explained in more detail. To this end, Figure 2 The cross section of the operating device 1 is shown. The drive unit 19 has a motor housing 20, in which an electric motor 21 is arranged. An annular rotor 22 of the electric motor 21 is arranged on a drive shaft 23 in a rotationally fixed manner, wherein the drive shaft 23 is mounted rotatably about an axis of rotation 24. An annular stator 25 of the electric motor 21 is arranged on the motor housing 20 in a manner fixed to the housing and radially surrounds the rotor 22 with reference to the axis of rotation 24. The motor housing 20 is fixed to the housing 7.

[0029] The drive shaft 23 is coupled to the pressure element 3 via a transmission 26 , so that the pressure element 3 can be moved by the motor 21 . Figure 3A sectional view of a transmission 26 is shown. The transmission 26 has a threaded spindle 27, which can be moved in a first direction 5 and in a second direction 6. The threaded spindle 27 is coupled to the pressure element 3 so that the pressure element 3 can be moved at least in the first direction 5 by the threaded spindle 27. The threaded spindle 27 has a thread 28. The thread 28 forms a drive toothing of the threaded spindle 27. The threaded spindle 27 is part of a transmission mechanism 29 of the transmission 26, which is designed to convert a rotation of the threaded spindle 27 into a translational movement. In the present case, the transmission mechanism 29 is designed as a spindle transmission mechanism 29. In addition to the threaded spindle 27, the spindle transmission mechanism 29 also has a spindle nut 30 that is rotatably supported. The spindle nut 30 and the threaded spindle 27 are arranged coaxially with each other. The driven toothing 60 of the spindle nut 30 meshes with the thread 28 of the threaded spindle 27, so that the threaded spindle 27 can be moved by rotating the spindle nut 30. According to another embodiment, the transmission 29 is not designed as a spindle transmission, but as a ball screw transmission.

[0030] According to the embodiment shown in the figures, the transmission 26 also has a worm gear 31 with a worm shaft 32 and a worm wheel 33. In this case, the worm shaft 32 is formed by the drive shaft 23. In the present case, the worm wheel 33 is arranged on the spindle nut 30 in a rotationally fixed manner. According to another embodiment, the spindle nut 30 and the worm wheel 33 are designed integrally with each other.

[0031] An anti-rotation element 35 is arranged on a first end section 34 of the threaded spindle 27 which faces toward or is associated with the pressure element 3 . Figure 4 The anti-rotation element 35 is shown in a top view, wherein the viewing direction corresponds to the second direction 6. The anti-rotation element 35 is connected to the threaded spindle 27 in a rotationally fixed manner. The rotationally fixed connection of the anti-rotation element 35 to the threaded spindle 27 is formed by a form-fit connection 36.

[0032] According to the embodiment shown in the figure, the anti-rotation element 35 has an annular section 61 with a channel 37. The threaded spindle 27 is inserted into the channel 37. The inner side 38 of the anti-rotation element 35, which forms or surrounds the channel 37, has a first engaging tooth portion 39, which has a first engaging portion 40 with a plurality of tooth shapes. The first engaging portion 40 protrudes radially inward from the inner side 38. The outer side 41 of the threaded spindle 27, which is arranged radially opposite to the inner side 38, has a second engaging tooth portion 42, which has a second engaging portion 43 with a plurality of tooth shapes. The second engaging portion 43 protrudes radially outward from the outer side 41. The first engaging tooth portion 39 meshes with the second engaging tooth portion 42 to form a shape-fitting connection 36.

[0033] The anti-rotation element 35 interacts with the housing 7 to form an anti-rotation portion 44 for the threaded spindle 27. According to another embodiment, the anti-rotation element 35 does not interact with the housing 7, but with an element fixed relative to the housing. In the present case, the anti-rotation element 35 has two radial projections 45, which project radially outward from the annular segment 61. However, there may also be a different number of radial projections 45. In the present case, the radial projections 45 are arranged offset by 180° in the circumferential direction of the anti-rotation element 35. The radial projections 45 radially engage in corresponding other radial recesses 46 of the housing 7 to form the anti-rotation portion 44. In the present case, a sliding pad 48 is arranged at the radial outer end 47 of the radial projection 45. Low-friction guidance of the radial projection 45 in the radial recess 46 is ensured by the sliding pad 48.

[0034] In the present case, the anti-rotation element 35 is made of glass fiber reinforced plastic, for example, by an injection molding process. The strength of this material makes a large design of the anti-rotation element 35 unnecessary. In order to reduce material costs, the anti-rotation element 35 is provided with a groove 49, so that the anti-rotation element 35 is constructed in a skeletonized manner. In the present case, the annular segment 61 has two annular segment-shaped grooves 49a. The radial protrusion 45 has a plurality of prismatic grooves 49b respectively. According to another embodiment, the anti-rotation element 35 is preferably made of a metal material, for example, by a cold forming process. The anti-rotation element 35 also preferably has a groove 49 when made of a metal material. The threaded spindle 27 including the thread 28 and the second engaging tooth portion 42 is preferably manufactured by a cold forming process.

[0035] The anti-rotation element 35 is also connected axially fixedly to the threaded spindle 27. In the present case, the threaded spindle 27 has an undercut 50 for this purpose. The undercut 50 extends along the threaded spindle 27 over the entire circumference in the circumferential direction of the threaded spindle 27. The anti-rotation element 35 is deformed by caulking so that the anti-rotation element 35 engages radially into the undercut 50. As an alternative to this, the anti-rotation element 35 is preferably connected axially fixedly to the threaded spindle 27 by a locking connection. For example, the anti-rotation element 35 has for this purpose at least one locking projection, which engages radially into the undercut 50. According to another embodiment, the anti-rotation element 35 has an undercut 50 and the threaded spindle 27 engages radially into the undercut 50 so that the anti-rotation element 35 is connected axially fixedly to the threaded spindle 27.

[0036] The actuating device 1 further comprises an actuating element 51 which is movably supported in an axial passage 52 of the threaded spindle 27. A first end 53 of the actuating element 51 is coupled or can be coupled to a brake pedal of the brake system 2 via an input rod 54, so that the actuating element 51 can be moved by actuating the brake pedal. A second end 55 of the actuating element 51 is coupled to the pressure element 3, so that the pressure element 3 can be moved by the actuating element 51. The friction brake device can also be actuated by actuating the brake pedal.

Claims

1. An operating device for a brake system, the operating device comprising: A motor (21), wherein The rotor (22) of the electric motor (21) is arranged in a rotationally fixed manner on a rotatably supported drive shaft (23); a movably supported pressure element (3); and a transmission (26), via which the drive shaft (23) is operatively connected to the pressure element (3), wherein the transmission (26) has a movable threaded spindle (27), wherein an anti-rotation element (35) is non-rotatably connected to the threaded spindle (27), and wherein the anti-rotation element (27) interacts with a housing (7) of the operating device (1) and / or with an element of the operating device (1) which is arranged fixedly relative to the housing to form an anti-rotation portion (44) for the threaded spindle (27), It is characterized in that the rotationally fixed connection of the anti-rotation element (35) to the threaded spindle (27) is formed by a form-fitting connection (36).

2. The operating device according to claim 1, characterized in that The form-fit connection (36) is formed by at least one radially protruding engagement portion (40, 43).

3. An operating device according to any one of the preceding claims, characterized in that The engaging toothing (39) of the anti-rotation element (35) meshes with the engaging toothing (42) of the threaded spindle (27) to form the form-fitting connection (36).

4. An operating device according to any one of the preceding claims, characterized in that The anti-rotation element (35) is made of plastic, in particular glass-fiber reinforced plastic.

5. The operating device according to any one of claims 1 to 3, characterized in that The anti-rotation element (35) is made of a metal material, in particular by a cold forming process.

6. An operating device according to any one of the preceding claims, characterized in that The rotation-protection element (35) is embodied in a skeletonized manner by means of a groove (49).

7. An operating device according to any one of the preceding claims, characterized in that The threaded spindle (27) is manufactured by a cold forming process.

8. An operating device according to any one of the preceding claims, characterized in that The anti-rotation element (35) is axially fixedly connected to the threaded spindle (27).

9. The operating device according to claim 8, characterized in that The threaded spindle (27) or the anti-rotation element (35) has an undercut (50) or an undercut portion, into which the anti-rotation element (35) or the threaded spindle (27) engages, so that the anti-rotation element (35) is axially fixedly connected to the threaded spindle (27).

10. The operating device according to any one of claims 8 and 9, characterized in that The anti-rotation element (35) is connected to the threaded spindle (27) in an axially fixed manner by shimming the anti-rotation element (35) and / or by shimming the threaded spindle.

11. An operating device according to any one of the preceding claims, characterized in that The threaded spindle (27) has a first end section (34) facing the pressure element (3), and the anti-rotation element (35) is arranged at the first end section (34).

12. An operating device according to any one of the preceding claims, characterized in that The anti-rotation element (35) has an annular section (61), and the threaded spindle (27) is inserted into a channel (37) of the annular section (61).

13. An operating device according to any one of the preceding claims, characterized in that The anti-rotation element (35) has at least one radial projection (45) which radially engages in a radial recess (46) of a housing (7) of the operating device (1) to form the anti-rotation portion (44).

14. The operating device according to claim 13, characterized in that A sliding pad (48) is arranged on the radial projection (45).

15. An operating device according to any one of the preceding claims, characterized in that The shell (7) is a cylindrical extruded profile (7).

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