Electromechanically actuatable brake piston assembly

Abstract

The invention relates to an electromechanically actuatable brake piston assembly. The brake piston assembly comprises: a caliper housing (10) having a bridge portion (11), a bridge finger portion (12) and a brake piston bearing portion (13); a brake piston (50) axially displaceable in a first bore (20) of the brake piston bearing part (13), the first bore having a bore axis (21) and a first bore wall (22); a rotational-translational transmission (56), in particular a screw drive, mounted in the interior space (55) of the brake piston (50); and an anti-rotation mechanism (5) having a guide groove (40) and a guide element (58) which is guided by means of the guide groove in such a way that the brake piston (50) is limited to its degree of freedom of axial movement. The guide groove (40) is comprised by the brake piston bearing portion (13) and the guide element (58) is fixedly connected to the brake piston (50).

Description

Field of the Invention

[0001] The present invention relates to an electromechanically actuable brake piston assembly for a motor vehicle disc brake. The present invention also relates to a motor vehicle disc brake having a brake piston assembly of this type and having an electromechanical drive, and the present invention relates to a partial method in the manufacture of a brake piston assembly of the type in question. Background Art

[0002] This type of brake piston assembly is used to support the axial movement of the brake piston, which is received in a guide hole of a brake piston support portion of a brake caliper housing, and to provide the brake piston such that it can be actuated by an electromechanical drive. In this way, the brake piston can transmit a pressing force to a brake lining, which in turn can press against a brake rotor with the pressing force and can brake the brake rotor.

[0003] The prior art discloses an electromechanically actuable brake piston assembly for a motor vehicle disc brake, wherein a rotation-translation transmission is received in the brake piston, and wherein the brake piston is supported in a brake piston support portion of a brake caliper housing such that the brake piston is axially movable and can be actuated by an electromechanical drive. The prior art also discloses providing an anti-rotation mechanism for the brake piston in such a brake piston assembly such that when the brake piston assembly is actuated, the brake piston does not rotate but moves in the axial direction.

[0004] DE102022119398A1 relates to an electromechanically driven brake piston assembly and a corresponding motor vehicle disc brake. Summary of the Invention

[0005] It is an object of the present invention to provide an electromechanically actuable brake piston assembly for a motor vehicle brake, which can be manufactured more economically, assembled relatively easily and operate reliably. This object also applies to a corresponding motor vehicle disc brake. It is also an object of the present invention to propose a partial method in the context of manufacturing an electromechanically actuable brake piston assembly, for which low manufacturing costs and relatively easy assembly are possible.

[0006] The object is achieved by the brake piston assembly according to the invention, by the motor vehicle disc brake according to the invention and by the method according to the invention.

[0007] The electro-mechanically actuable brake piston assembly according to the invention is provided for a motor vehicle disc brake and has a brake caliper housing. When in the following description only the term "brake piston assembly" is used for better readability without the preceding expression "electro-mechanically actuable", this should always be understood to refer to the electro-mechanically actuable brake piston assembly. The brake caliper housing includes a bridge portion, bridge fingers, and a brake piston support portion. Since the brake caliper housing is known from the prior art, it is not necessary to describe the brake caliper housing in more detail here. Of course, the brake caliper housing of the present invention can be within the scope of known embodiments. For example, the brake caliper housing can be designed such that the brake piston support portion is connected to two bridge fingers via the bridge portion, the bridge fingers are located on the outer side of the associated motor vehicle disc brake, and the brake piston support portion of the brake caliper housing is oriented towards the inner side of the associated vehicle (i.e., towards the chassis).

[0008] The brake piston assembly further includes: a brake piston that can axially move in a first hole of the brake piston support portion, the first hole having a hole axis and a first hole wall; and a rotary-translatory transmission device that is installed in the internal space of the brake piston. The rotary-translatory transmission device is preferably a screw drive. The brake piston assembly further includes an anti-rotation mechanism. The anti-rotation mechanism has a guide groove included in the brake piston support portion and a guide element fixedly connected to the brake piston. The guide element is preferably pressed into the piston. In this case, the piston has a recess in its side surface, the guide element is inserted into the recess, and the guide element is held in the recess by a press fit, adhesive bonding, or some other type of connection (such as a threaded connection). The guide element is preferably a key, a groove block, or a guide pin. The guide element is guided by means of the guide groove such that the brake piston is restricted to its axial degree of freedom of movement. That is, the brake piston can move axially, in particular by actuation of the brake piston assembly. In contrast, the rotation of the brake piston is hindered or prevented by the anti-rotation mechanism. By introducing the guide groove into the brake piston support portion and coupling the guide element to the brake piston, better assembly is achieved.

[0009] The expression "axial" or in the "axial direction" relates to the orientation of the hole axis. That is, "axial" means parallel to the hole axis or extending along the axis.

[0010] Preferably, the brake caliper housing is a monolithic casting. This design of directly introducing the guide groove into the casting results in an economically manufacturable brake piston assembly.

[0011] Preferably, the brake piston has a side surface that directly contacts the first hole wall for guiding the brake piston. That is, here there is no need for an additional guide element, such as a guide bushing, to support and guide the brake piston. This also has a favorable impact on the manufacturing cost.

[0012] Preferably, the rotation-translation drive is a screw drive, and more preferably, a ball screw drive without self-locking. In this case, the brake piston has a cylindrical inner wall that delimits the inner space of the brake piston. That is to say, the inner space of the brake piston is delimited by the cylindrical inner wall. The inner space can be delimited by additional wall regions, for example, by the end wall of the brake piston, which faces the brake lining or the brake disc when the brake piston assembly is installed in a motor vehicle disc brake. The brake piston is in the form of a nut, and one or more threads are formed in the inner wall. In the case of a ball screw drive, one or more corresponding ball races are formed in the inner wall. This design also helps to reduce manufacturing costs, similar to the guiding grooves introduced into the brake piston support part and similar to the use of the first hole wall to guide the brake piston, because more functions are achieved with fewer components. Preferably, one or more ball races cooperate directly with a screw placed in the brake piston through corresponding balls, and the screw can also have one or more ball races.

[0013] Preferably, guiding grooves are formed in the first hole wall and accordingly recess the first hole wall. Regarding the resulting advantages, reference is made to the previous paragraphs in which the advantages have been given.

[0014] Preferably, the guiding grooves are in the form of elongated holes, and the longitudinal axis of the elongated holes is oriented parallel to the hole axis of the first hole. In this case, the guiding grooves in the form of elongated holes penetrate the brake piston support part from the outside of the brake piston support part in a radial direction towards the hole axis to reach the first hole. The guiding element is at least partially received in the guiding grooves. The outside of the brake piston support part faces the surroundings of the brake caliper housing and is formed by a corresponding surface. Thus, the outside of the brake piston support part is located at a position where the brake caliper housing is delimited towards the surroundings in the region of the brake piston support part. Such penetrating guiding grooves, especially in the form of elongated holes, are relatively easy to manufacture and thus help to reduce costs.

[0015] Preferably, the brake piston support part has a recess that is introduced into the outside of the brake piston support part (the term "outside" is described in the previous paragraphs), and the recess has a recess bottom that sinks into the brake piston support part and a recess wall that connects the recess bottom and the outside, such that the guiding grooves form a through-hole between the recess bottom and the first hole, and the recess is closed outwardly by a cover. During the assembly of the brake piston assembly, the recess can be closed with such a cover. The cover protects the anti-rotation mechanism and thus also protects the brake piston, the rotation-translation drive, and the first hole from contaminants, and thus ensures reliable operation during the operation of the brake piston assembly and the associated motor vehicle disc brake.

[0016] Preferably, the recess wall is cylindrical with a first inner diameter (Di1).

[0017] Preferably, the lid has a lid edge, and at least one slit is engraved in the lid edge, extending from the lid edge and towards the lid center, such that the diameter of the lid edge is elastically variable.

[0018] Preferably, the lid has a lid edge, and at least five slits are engraved in the lid edge, extending from the lid edge and towards the lid center, such that the diameter of the lid edge is elastically variable, and the at least five slits are spaced apart from each other, particularly evenly distributed within a range of 360°.

[0019] Preferably, the lid has a planar inner lid portion that covers the guide groove in the mounted state, wherein the lid edge surrounds the inner lid portion and projects from the inner lid portion by means of at least one first bending portion, and wherein the at least one slit or the at least five slits are at least partially engraved in the bending portion. With an elastic lid edge of this type, in particular by virtue of the nature of the slits cooperating with the bending portion, the lid can be easily inserted into the recess and still held firmly in the recess.

[0020] When the term "bending portion" is used in connection with the present invention, such a bending portion may include a simple change in the direction of the lid edge relative to the inner lid portion; however, it may also include one or more additional changes in the direction of the lid edge of the bending portion relative to the already bent portion of the lid edge. For example, a first portion of the lid edge may project from the planar inner lid portion at an angle (e.g., a 90° angle), and an additional portion of the lid edge may in turn project at an angle (e.g., a 90° angle) relative to the already bent first portion of the lid edge. The foregoing description of the bending member is based on a half-sectional view of the lid edge or the lid, in which the lid edge can be seen in the contour. The term "bending portion" is also not an indication of a particular method for manufacturing the lid and the lid edge; rather, it is used to describe the shape of the lid edge. Thus, the term "bending portion" here also includes a bending portion extending along a preferably circular lid edge.

[0021] Preferably, the lid edge is shaped such that: the lid edge can be inserted into the recess due to elastic deformation of the lid edge, and can only be pulled out against the insertion direction in the case of plastic deformation of the lid edge.

[0022] Preferably, the recess has an annular groove with a groove base, or the recess has a hole offset portion with a second hole wall, the groove base or the second hole wall having a second inner diameter (Di2) greater than the first inner diameter (Di1), and the lid is held in the annular groove or the hole offset portion in a form-locking manner by its lid edge shape in the inserted state, and at this position, the outer diameter of the lid edge is greater than the first inner diameter (Di1).

[0023] Preferably, the lid edge has a first outer diameter (Da1) when not inserted into the recess and a second outer diameter (Da2) that is smaller than the first outer diameter (Da1) when inserted into the recess, and the lid edge is clamped in the recess wall when inserted into the recess. In such a clamped situation, the lid edge can also be pressed into the recess wall. The lid (especially the lid edge, optionally the bent part) can be designed such that the clamping force increases as the axial force acting in the insertion direction of the lid increases.

[0024] Preferably, the brake piston assembly includes a seal that, together with the lid, isolates the first hole from the surroundings of the brake piston assembly. The sealing protection of the anti-rotation mechanism and thus also the protection of the brake piston, the rotary-translatory drive, and the first hole from contaminants can be achieved in this way, and thus reliable operation is ensured during the operation of the brake piston assembly and the associated motor vehicle disc brake.

[0025] Preferably, the seal is made of an elastomer that can be elastically deformed, especially rubber.

[0026] Preferably, in the installed state, the seal exerts a force on the lid due to elastic deformation. Particularly preferably, in the installed state, the seal exerts a force on the lid due to elastic deformation in the axial direction. This contributes to the ideal sealing of the lid and the fixing of the position of the lid. Therefore, this results in easy assembly and reliable operation of the brake piston assembly and the associated motor vehicle disc brake.

[0027] Preferably, the seal is annular and has a cross-section that is circular or oval or polygonal (e.g., rectangular). The seal is placed between the recess bottom and the first bent part or between the recess bottom and the second bent part included by the lid edge, and the second bent part is located between the first bent part and the inner lid part. Similar to the above possible designs of the first bent part, the second bent part can also include a first and additional change in the direction of a part of the lid edge.

[0028] Preferably, at least most of the inner lid part is planar. In this case, the second bent part includes an annular disc-shaped part, and the annular disc-shaped part of the second bent part and the planar inner lid part are oriented parallel to each other.

[0029] Preferably, the seal is annular and has a cross-section that is circular or oval or polygonal (e.g., rectangular). The seal is placed between the recess wall and the first bent part or between the recess wall and the second bent part included by the lid edge, and the second bent part is located between the first bent part and the inner lid part.

[0030] Preferably, the seal is disc-shaped and arranged between the bottom of the recess and the cover, preferably between the bottom of the recess and the inner cover part. Alternatively, the seal is disc-shaped and arranged between the bottom of the recess and the pressure plate, which is included by the electromechanically actuable brake piston assembly and abuts against the cover.

[0031] In all embodiments of the cover, the cover is preferably made of a plate, more preferably made of a metal plate. Such a cover is economical and contributes to the cost optimization of the brake piston assembly.

[0032] The motor vehicle disc brake according to the invention comprises a brake carrier, an electromechanical drive and a brake piston assembly having the corresponding components, features and advantages according to the foregoing embodiments, the electromechanical drive having a transmission assembly and an electric motor, and the brake piston assembly being actuable by the electromechanical drive.

[0033] A partial method according to the invention for manufacturing an electromechanically actuable brake piston assembly according to the foregoing embodiments at least comprises the following method steps:

[0034] a) Introducing a guide groove, preferably milling out the guide groove, preferably in the form of a slot which starts from the outside of the brake piston support part and reaches a first hole in the radial direction towards the hole axis;

[0035] b) Drilling, spindle turning or milling out a recess, or drilling, spindle turning or milling out a recess and an annular groove or a hole offset section;

[0036] c) Inserting the seal into the first recess or mounting the seal on the cover;

[0037] d) Inserting the cover into the recess and locking the cover edge in the annular groove or the hole offset section, or inserting the cover into the recess and clamping the cover edge into the first recess wall.

[0038] Alternatively, the partial method according to the invention at least comprises the following method steps:

[0039] According to the method steps a) to d) of the foregoing paragraph, method step b) is carried out before method step a).

[0040] The advantages of the partial method according to the invention are that the guide groove can be manufactured easily and economically. In addition, the assembly sequence is particularly advantageous. Description of the Drawings

[0041] Other features, advantages and possible applications of the invention result from the following description of the exemplary embodiments and from the schematic Figures 1 to 11It is clear. For the sake of clarity, not all elements shown in the figures are always provided with reference numerals. However, the corresponding elements or regions are subsequently at least marked in another figure and the meaning can be derived therefrom. Also, in the figures, the same reference numeral can denote the same or similar objects.

[0042] Figure 1 The design of the brake piston assembly is shown in an overall view, presenting a first exemplary embodiment of the present invention.

[0043] Figure 2 Details of the brake piston assembly according to the present invention are shown.

[0044] Figure 3 Two illustrations of a second exemplary embodiment of the brake piston assembly according to the present invention are shown.

[0045] Figure 4 Another illustration of a second exemplary embodiment of the brake piston assembly according to the present invention is shown.

[0046] Figure 5 An illustration of a third exemplary embodiment of the brake piston assembly according to the present invention is shown.

[0047] Figure 6 Two illustrations of a fourth exemplary embodiment of the brake piston assembly according to the present invention are shown.

[0048] Figure 7 Another illustration of a fourth exemplary embodiment of the brake piston assembly according to the present invention is shown.

[0049] Figure 8 An illustration of a fifth exemplary embodiment of the brake piston assembly according to the present invention is shown.

[0050] Figure 9 An illustration of a sixth exemplary embodiment of the brake piston assembly according to the present invention is shown.

[0051] Figure 10 Two illustrations of a seventh exemplary embodiment of the brake piston assembly according to the present invention are shown.

[0052] Figure 11 An illustration of an exemplary embodiment of a motor vehicle disc brake according to the present invention is shown. Detailed Description

[0053] Figure 1 and Figure 2Shows a design of a brake piston assembly 1 according to the present invention. In the shown state of the brake piston assembly 1, the area of the anti-rotation mechanism 5 is not enclosed outwardly, so that the anti-rotation mechanism 5 is visible. The brake piston assembly 1 includes a brake caliper housing 10, which has: a bridge portion 11, two bridge finger portions 12, and a brake piston support portion 13. A brake disc shaft 16 is located between the bridge finger portions 12 and the brake piston support portion 13. When the brake piston assembly 1 and the associated motor vehicle disc brake 100 are installed on a vehicle or a vehicle axle, a brake disc is placed in this brake disc shaft and can rotate. The brake piston support portion 13 is part of the integral brake caliper housing 10 produced as a casting. The brake piston support portion 13 has a first hole 20, which has a hole axis 21 and a hole wall 22. The brake piston 50 is axially movably supported in the first hole 20. The brake piston 50 departs from the brake piston support portion 13 on the side of the brake piston support portion 13 oriented towards the brake disc shaft 16, that is, from the brake caliper housing 10, so that the brake piston can apply a driving force to the brake lining and the brake disc by means of its end wall 54. The brake piston 50 has a side surface 51 that is in sliding contact with the hole wall 22.

[0054] A guiding element 58 in the form of a cylindrical body is provided in the brake piston 50, in particular in the side surface 51. Figure 1 and Figure 2 This is shown in a basic form. The guiding element 58 can be fastened in the brake piston 50 in different ways. It is preferably screwed into the brake piston 50. But it can also be fastened in the brake piston 50 in any other way. The guiding element 58 is part of the anti-rotation mechanism 5, by which the rotation of the brake piston 50 is prevented, but the axial movement of the brake piston 50 is allowed and realized. Therefore, the guiding element 58 acts as a guiding block or a slot block guided in a corresponding guiding slot 40. The guiding slot 40 is formed or recessed into the brake piston support portion 13 of the brake caliper housing 10 in the form of a slotted hole. Therefore, the guiding slot 40 is shaped and oriented to translate the guiding element 58 and thus translate the brake piston 50.

[0055] Where the anti-rotation mechanism 5 is located, there is also a recess 30 introduced into the exterior 14 of the brake piston support portion 13. The recess 30 is in the form of a cylindrical depression and radially depresses from the exterior 14 towards the hole axis 21. Therefore, the recess 30 has a recess bottom 31 and a recess wall 32, and the recess bottom 31 is closer to the first hole 20 or the hole axis 21 of the first hole than the exterior 14. In the current case, the recess wall 32 is a cylindrical recess wall having a first inner diameter Di1. A detailed description of the recess 30 will be given in the following description.

[0056] The elongated hole forming the guide groove 40 forms a through hole between the recess bottom 31 and the hole wall 22. The elongated hole 40 penetrates the brake piston support portion 13 in the radial direction. The longitudinal axis 41 of the elongated hole 40 is oriented parallel to the hole axis 21 of the first hole 20. Such a guide groove can be machined relatively simply from the outside 14 of the brake piston support portion 13 because this area is easily accessible to the corresponding tools. The guide element 58 extends into the guide groove 40 and is guided by the straight side walls of the elongated hole 40 such that the brake piston 50 can only move in the axial direction 3.

[0057] Figures 3 to 11 A further exemplary embodiment of the invention is shown. The focus is on the design of the recess 30 and the cover 60. The brake piston assembly 1 generally corresponds to the exemplary embodiment of the brake piston assembly 1 already described above based on Figure 1 and Figure 2 Since the drawings contain schematic views, the seal 80 is not always shown in its actual shape. Thus, the material overlaps that may be shown in the illustration are also only the result of the drawing and do not occur in reality in this way.

[0058] Figure 3 and Figure 4 Each shows a part of a second exemplary embodiment of the brake piston assembly 1 according to the invention. The recess 30 has a recess bottom 31 and a cylindrical recess wall 32. The elongated hole 40 forms a through hole between the recess bottom 31 and the hole wall 22. An annular groove 33 is formed in the recess wall 32, and the groove base 34 of the annular groove has a second inner diameter Di2 that is larger than the first inner diameter Di1 of the cylindrical recess wall. A cover 60 is inserted into the recess 30.

[0059] The cover 60 is a plate-like structure made of a metal plate and has a flat in-plane cover portion 64. A cover edge 61 extends around the inner cover portion 64. The cover edge 61 has two curved portions 65 and 75, the shapes of which are as follows. The first curved portion 65 is formed by a flange 66 that points radially outward and is oriented substantially parallel to the inner cover portion 64. The flange is adjacent to a plate-like portion that extends in the axial direction and is oriented perpendicular to the flange 66. The junction between the flange 66 and the plate-like portion extending in the axial direction is formed as a radius. The second curved portion 75 is located between the first curved portion 65 and the inner cover portion 64. The second curved portion is adjacent to the above-mentioned plate-like portion extending in the axial direction via a junction formed as a radius. The second curved portion 75 has an annular disc-like portion 76 that is oriented parallel to the inner cover portion 64 and is connected to the inner cover portion 64 by another plate-like portion that extends in the axial direction. All junctions between the respective plate-like portions or curved portions are in the form of a radius.

[0060] A plurality of slits 63 (each slit extending in the radial direction 2) are cut into the cover edge 61 at the outermost contour of the cover edge 61. The slits 63 cut the cover edge 61 into the first bending portion 65. The slits 63 are evenly distributed within the 360° range of the cover edge 61. The slits 63 form separate cover edge sections, and thus the outer diameter of the cover edge 61 can be elastically deformed, in particular, can be elastically reduced in size, resulting in favorable mountability of the cover.

[0061] An O-ring, i.e., an annular seal 80 having a circular cross-section, is arranged between the annular disc-shaped portion 76 and the recess bottom 31. The seal isolates the first hole 20, the anti-rotation mechanism 5, the rotation-translation transmission 56, and other parts from the surrounding environment. The seal 80 contacts the annular disc-shaped portion 76, the recess bottom 31, and the recess wall 32 of the cover 60 and is pressed between these elements by means of the assembly process, thereby achieving a sealing effect and reliable positioning of the cover, because in this way, the cover edge 61 is pressed against the groove wall of the annular groove 33 in a form-locked manner.

[0062] Figure 5 A part of a third exemplary embodiment of the brake piston assembly 1 according to the present invention is shown. The third exemplary embodiment differs from the second exemplary embodiment only in the cross-sectional shape of the seal 80. Here, the cross-section is not circular but square or rectangular (depending on the compression state). This embodiment of the seal 80 provides a higher preloading force, which acts on the cover 60 when the seal 80 is compressed. The design of the brake piston assembly 1 is the same as that of the second exemplary embodiment in other aspects and does not need to be described again here.

[0063] Figure 6 and Figure 7 Each shows a part of a fourth exemplary embodiment of the brake piston assembly 1 according to the present invention. The fourth exemplary embodiment differs from the second exemplary embodiment in that the recess 30 does not have an annular groove. That is, the recess 30 is formed by the recess bottom 31 and the recess wall 32. In addition, the cover edge 61 of the cover 60 only has the first bending portion 65. The first bending portion 65 has an annular disc-shaped portion 76, which is parallel and offset from the inner cover portion 64, and the annular disc-shaped portion is connected to the inner cover portion 64 by an axially extending plate-like portion. Towards the outside, the annular disc-shaped portion 76 is adjacent to a flange 66 that extends in both the radial direction and the axial direction, so that through the flange 66, the outermost contour of the cover edge 61 is pressed and clamped into the recess wall 32. The shape of the cover 60 in this fourth exemplary embodiment is less complex and is therefore more economical than the shape of the second exemplary embodiment. The situation of the recess 30 is similar. Similarly, in the cover 60 of this fourth exemplary embodiment, the slits 63 are cut into the cover edge 61. The more detailed description of the slits and their arrangement corresponds to the description of the slits in the second exemplary embodiment.

[0064] An O-ring, i.e., an annular seal 80 with a circular cross-section, is arranged between the annular disc-shaped part 76 and the bottom 31 of the recess. The seal isolates the first hole 20, the anti-rotation mechanism 5, the rotation-translation transmission 56 and other parts from the surrounding environment. The seal 80 contacts the annular disc-shaped part 76 of the cover 60, the bottom 31 of the recess and the recess wall 32. The seal 80 is pressed between these elements by means of the assembly process, thus achieving a sealing effect and reliable positioning of the cover, since the cover edge 61 is pressed against and pressed into the recess wall 32.

[0065] Figure 8 A part of a fifth exemplary embodiment of the brake piston assembly 1 according to the present invention is shown. The difference between this fifth embodiment and the fourth embodiment lies only in the cross-sectional shape of the seal 80. Here, the cross-section is not circular, but square or rectangular (depending on the compression state). The design of the brake piston assembly 1 is the same as that of the fourth exemplary embodiment in other aspects and does not need to be described again here.

[0066] Figure 9 A part of a sixth exemplary embodiment of the brake piston assembly 1 according to the present invention is shown. In this exemplary embodiment, the seal 80 between the substantially or at least mainly axially oriented plate part of the first bent part 65 of the cover edge 61 and the recess wall 32 or the annular groove provided in the recess wall 32 isolates the first hole 20, the anti-rotation mechanism 5, the rotation-translation transmission 56 and other parts from the surrounding environment of the brake piston assembly 1. The cover edge 61 is held in the annular groove 33 provided in the recess by a flange 66 that points radially outwards and abuts the substantially or at least mainly axially oriented plate part. In this exemplary embodiment, the size of the annular groove 33 ensures the position of the cover 60.

[0067] In Figure 10 In the seventh exemplary embodiment shown, the seal 80 is in the form of a disc-shaped element that is placed on the bottom 31 of the recess and covers the bottom of the recess and the guide groove 40. Here, the cover 60 has the same design as in the fourth and fifth exemplary embodiments. There is a pressing disc 85 between the inner cover part 64 and the seal 80. The resulting sealing set including the cover 60, the pressing disc 85 and the seal 80 provides sealing. The cover 60 is held by the elastic cover edge 61 in the same way as in the previously described exemplary embodiments and does not need to be described again here.

[0068] Figure 11An exemplary embodiment of a motor vehicle disc brake according to the present invention is shown. The brake caliper housing 10 and thus the brake piston assembly 1 are supported for axial movement relative to the brake carrier 101 and are connected to the brake carrier. An electromechanical drive 105 including a transmission assembly 106 and an electric motor 107 is coupled to the brake piston assembly 1, in particular to the brake piston support portion 13 of the brake caliper housing 10, and is used to actuate the brake piston 50.

Claims

1. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100), the brake piston assembly comprising: A brake caliper housing (10) having a bridge portion (11), a bridge finger portion (12) and a brake piston support portion (13); a brake piston (50) which can move axially in a first hole (20) of the brake piston support portion (13), the first hole having a hole axis (21) and a first hole wall (22); a rotational-translational transmission (56), in particular a screw drive, which is installed in the interior space (55) of the brake piston (50); as well as an anti-rotation mechanism (5) having a guide groove (40) and a guide element (58) which is guided by means of the guide groove (40) in such a way that the brake piston (50) is restricted in its axial freedom of movement, It is characterized in that the guide groove (40) is comprised by the brake piston bearing part (13) and that the guide element (58) is fixedly connected to the brake piston (50), in particular is pressed into the brake piston (50).

2. The electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to claim 1, wherein: The brake caliper housing (10) is an integral casting.

3. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of the preceding claims, wherein: The brake piston (50) has a side surface (51) which is in direct contact with the first hole wall (22) for guiding the brake piston (50), and / or wherein the rotational-translational transmission device (56) is a screw drive, in particular a non-self-locking ball screw drive, wherein the interior space (55) of the brake piston (50) is defined by a cylindrical inner wall (52), and wherein the brake piston (50) is in the form of a nut, one or more threads (53) of the nut or one or more ball raceways (53) of the nut being formed in the inner wall (52).

4. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of the preceding claims, wherein: The guide groove (40) is formed in the first hole wall (22) and correspondingly recesses the first hole wall (22).

5. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of the preceding claims, wherein: The guide groove (40) is in the form of an elongated hole, the longitudinal axis (41) of which is oriented parallel to the hole axis (21) of the first hole (20), and the elongated hole penetrates the brake piston support part (13) from the outside (14) of the brake piston support part (13) in a radial direction (2) toward the hole axis (21) to reach the first hole (20), wherein the guide element (58) is at least partially accommodated in the guide groove (40).

6. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of the preceding claims, wherein: The brake piston support part (13) has a recess (30), which is introduced into the exterior (14) of the brake piston support part (13), and the recess has a recess bottom (31) sunken into the brake piston support part (13) and a recess wall (32) connecting the recess bottom (31) and the exterior (14), so that the guide groove (40) forms a through hole between the recess bottom (31) and the first hole (20), wherein the recess (30) is closed to the outside and / or can be closed to the outside by a cover (60).

7. The electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to claim 6, wherein: The recess wall (32) is cylindrical with a first inner diameter (Di1).

8. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of the preceding claims, wherein: The cover (60) has a cover edge (61) engraved with at least one slit (63) starting from the cover edge and extending towards the cover center (62), so that the diameter of the cover edge (61) is elastically variable, and / or The cover (60) has a cover edge (61) on which at least five slits (63) are engraved, starting from the cover edge and extending toward the cover center (62), so that the diameter of the cover edge (61) is elastically variable, and the at least five slits are spaced apart from each other, in particular, evenly distributed within a range of 360°.

9. The electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to claim 8, wherein: The cover (60) has a planar inner cover part (64) which covers the guide groove (40) in the installed state, wherein the cover edge (61) surrounds the inner cover part (64) and protrudes from the inner cover part by means of at least one first curved part (65), wherein the at least one slit (63) or the at least five slits (63) are at least partially engraved into the at least one first curved part (65).

10. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 8 to 9, wherein: The cover edge (61) is shaped such that it can be inserted into the recess (30) due to elastic deformation and the cover (60) can be pulled out counter to the insertion direction only with plastic deformation of the cover edge and / or the cover.

11. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 8 to 10, wherein: The recess (30) has an annular groove (33) having a groove base (34), or the recess (30) has a hole offset portion (33) having a second hole wall (34), wherein the groove base (34) or the second hole wall (34) has a second inner diameter (Di2) greater than the first inner diameter (Di1), and In which the cover (60) is held in the annular groove (33) or in the hole offset portion (33) in a form-locked manner via its cover edge (61) in the inserted state, and in which, in this position, the outer diameter of the cover edge (61) is greater than the first inner diameter (Di1).

12. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 8 to 10, wherein: The cover edge (61) has a first outer diameter (Da1) when not inserted into the recess (30), and has a second outer diameter (Da2) smaller than the first outer diameter (Da1) when inserted into the recess (30), wherein the cover edge (61) is clamped and / or pressed into the recess wall (32) when inserted into the recess (30).

13. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 6 to 12, wherein: The electromechanically actuatable brake piston assembly (1) comprises a seal (80) which, together with the cover (60), isolates the anti-rotation mechanism (5) and the first hole (20) from the surrounding environment of the electromechanically actuatable brake piston assembly (1).

14. The electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to claim 13, wherein: The sealing member (80) is made of an elastically deformable elastomer, in particular rubber.

15. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to claim 13 or 14, wherein: In the installed state, the seal (80) exerts a force on the cover (60) due to elastic deformation, in particular due to elastic deformation in the axial direction (3).

16. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 13 to 15, wherein: The seal (80) is annular and has a circular, oval or polygonal, especially rectangular, cross section. The seal (80) is placed between the bottom of the recess (31) and the first curved portion (65) or between the bottom of the recess (31) and a second curved portion (75) included by the cover edge (61), and the second curved portion is located between the first curved portion (65) and the inner cover portion (64).

17. The electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to claim 16, wherein: At least a majority of the inner cover portion (64) is planar, wherein the second curved portion (75) comprises an annular disc-shaped portion (76), and Wherein, the annular disk-shaped portion (76) of the second curved portion (75) and the planar inner cover portion (64) are oriented parallel to each other.

18. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 13 to 16, wherein: The seal (80) is annular and has a circular, oval or polygonal, especially rectangular, cross section, and The seal (80) is placed between the recess wall (32) and the first curved portion (65) or between the recess wall (32) and a second curved portion (75) comprised by the cover edge (61), the second curved portion being located between the first curved portion (65) and the inner cover portion (64).

19. An electromechanically actuatable brake piston assembly (1) for a motor vehicle disc brake (100) according to any one of claims 13 to 16, wherein: The seal (80) is disc-shaped and is arranged between the recess bottom (31) and the cover (60), in particular between the recess bottom (31) and the inner cover part (64), and / or The seal (80) is disc-shaped and is arranged between the recess bottom (31) and a pressure plate (85) which is included in the electromechanically actuatable brake piston assembly (1) and is placed against the cover (60).

20. A motor vehicle disc brake (100), comprising a brake support (101), an electromechanical drive (105) and a brake piston assembly (1) according to any one of claims 1 to 19, wherein the electromechanical drive has a transmission assembly (106) and an electric motor (107), and the brake piston assembly can be actuated by the electromechanical drive (105).

21. A partial method for producing an electromechanically actuatable brake piston assembly (1) according to any one of claims 1 to 19, the partial method comprising at least the following method steps: a) introducing the guide groove (40), preferably milling the guide groove (40), in particular the guide groove (40) is in the form of an elongated hole, which starts from the outer part (14) of the brake piston bearing part (13) and reaches the first hole (20) in a radial direction (2) towards the hole axis (21); b) drilling, spindle turning or milling the recess (30), or drilling, spindle turning or milling the recess (30) and the annular groove (33) or the hole offset portion (33); c) inserting the sealing member (80) into the first recess (30), or installing the sealing member (80) on the cover (60); d) inserting the cover (60) into the recess (30) and locking the cover edge in the annular groove (33) or in the hole offset portion (33), or inserting the cover (60) into the recess (30) and clamping the cover edge to the first recess wall (32), or A partial method for producing an electromechanically actuatable brake piston assembly (1) according to any one of claims 1 to 19 comprises at least the following method steps: a) to d), where: Method step b) is carried out before method step a).

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