Two-piece brake disc for a vehicle and method for its manufacture

Abstract

The invention relates to a two-part brake disc (1) for a vehicle comprising a brake pot (2) formed from a sheet metal by forming and having external teeth (3) on an outer circumferential surface, and a friction ring (4) formed from gray cast iron by primary forming and having internal teeth (5) on an inner circumferential surface which engage in the external teeth (3) on the brake pot (2) for a rotationally fixed connection, wherein the friction ring (4) has several axial recesses (6) and the brake pot (2) has several plug-in elements (7), wherein each recess (6) receives a plug-in element (7) which extends from a first end face of the friction ring (4) through the respective recess (6) to the second end face of the friction ring (4) and is designed for axially fixing the friction ring (4) to the brake pot (2).

Description

[0001] The invention relates to a two-piece brake disc for a vehicle. Furthermore, the invention relates to a method for producing such a two-piece brake disc. The invention also relates to a vehicle with such a two-piece brake disc.

[0002] One-piece cast brake discs are commonly known, in which both the friction ring and the brake chamber are made of a single cast material. The disadvantage of such a one-piece design is its high weight. To reduce weight, two-piece composite brake discs have been developed, featuring a brake chamber made of steel or aluminum and a friction ring made of gray cast iron.

[0003] For example, EP 2 673 525 A1 discloses a two-part composite brake disc for a motor vehicle, comprising a brake disc chamber and at least one associated brake ring, which are joined together by means of a joining process. In a joining region, an inner brake ring tooth profile engages with a brake disc chamber tooth profile. The brake disc chamber tooth flanks of the brake disc chamber tooth profile and the brake ring tooth flanks of the brake ring tooth profile have different fits in the joining region. The brake disc chamber has a conical basic shape before the joining process. The inner brake ring tooth profile and / or the brake disc chamber tooth profile are elastically-plastically deformed at least in the region of the respective tooth flanks due to the joining process.

[0004] Furthermore, FR 2 931 219 A1 discloses a two-part brake disc with a rotor comprising a friction ring with a centrally symmetrical axis of rotation and a cylindrical inner wall to which a projection structure oriented toward the central axis is attached, separating two radial slots. A shell has a cylindrical outer wall on which tabs define an axial slot. The tabs engage in the respective radial slots and bear against the projection, allowing the projection to slide radially in the axial slot. The outer wall is formed by stamping a metal sheet. A method for manufacturing a rotor for a disc brake is also disclosed.

[0005] Furthermore, DE 44 20 758 A1 discloses a brake disc consisting of a friction ring and a bowl-shaped retaining part made of sheet metal, which is positively connected to the friction ring. The friction ring is provided on its inner edge region with radially inwardly open recesses, which divide the inner edge region into radially inwardly projecting teeth. The retaining part is provided on its outer edge region with securing tongues and stop tongues, which are alternately distributed over the circumference. Ends of the securing tongues, which are flanged radially outward, engage in the recesses of the friction ring in a positively locking manner. Ends of the stop tongues, which are bent radially outward, engage the teeth of the friction ring and form a stop for the positive engagement of the friction ring at least in one axial direction.

[0006] The object of the present invention is to provide an alternative two-piece brake disc for a vehicle. In particular, the manufacturing process for such a brake disc is to be optimized. This object is achieved by a two-piece brake disc having the features of independent patent claim 1. Advantageous embodiments are the subject of the dependent claims, the following description, and the figures.

[0007] A two-part brake disc for a vehicle according to the invention comprises a brake pot which is formed from a metal sheet by forming and has an external toothing on an outer circumferential surface, and a friction ring which is formed from a gray cast iron by primary forming and has an internal toothing on an inner circumferential surface which engages in the external toothing on the brake pot for a rotationally fixed connection, wherein the friction ring has a plurality of axial recesses and the brake pot has a plurality of plug-in elements, wherein each recess receives a plug-in element which extends from a first end face of the friction ring through the respective recess to the second end face of the friction ring and is designed for the axial fixing of the friction ring to the brake pot.

[0008] The rotationally fixed connection for torque transmission between the brake chamber and the friction ring is thus achieved by the engagement of the internal and external teeth, which are axially inserted into one another during assembly of the two-part brake disc. The internal and external teeth are designed as splines with radially formed teeth and tooth gaps. The teeth and tooth gaps of the respective toothing alternate in the circumferential direction. In particular, the teeth of the external toothing complement the tooth gaps of the internal toothing, while the teeth of the internal toothing complement the tooth gaps of the external toothing.

[0009] The friction ring is axially fixed to the brake chamber by the engagement of the plug-in elements in the recesses provided for this purpose. In particular, an end section of the respective plug-in element is formed in such a way that non-destructive removal of the plug-in elements from the recesses is impossible. For example, an end section of the respective plug-in element, in particular a free end of the respective plug-in element, is formed, in particular hot-stitched, crimped, or folded, in such a way that at least one positive and / or non-positive connection for axial fixation is established.

[0010] According to the invention, each plug-in element has three legs connected to one another in one piece. The first leg is designed for axial engagement with the first end face of the friction ring, the second leg is designed for arrangement in the respective recess on the brake housing, and the third leg is designed for axial engagement with the second end face of the friction ring. In particular, the first leg is connected in one piece to the collar on the brake housing, and the second leg is arranged between the first leg and the third leg and is connected in one piece to the first leg and the third leg.The friction ring is thus axially fixed between the first leg, against which the first end face of the friction ring comes into contact, and the third leg, against which the second end face of the friction ring comes into contact, wherein the second leg is guided axially through the respective recess and connects the first and third legs to one another in one piece.

[0011] According to a method according to the invention for producing the two-part brake disc, the brake pot is first formed by forming from a metal sheet, wherein an external toothing and a plurality of plug-in elements are formed on an outer peripheral surface of the brake pot. Preferably, the brake pot with the external toothing is formed by deep-drawing the metal sheet, and the plug-in elements are formed by bending flat webs on the outer peripheral surface of the brake pot. In particular, the brake pot is cylindrical, i.e. not conical, and thus has a substantially constant diameter. At the same time or at a later time, the friction ring can be formed by primary forming from gray cast iron, wherein the friction ring has an internal toothing on an inner peripheral surface, which engages with the external toothing on the brake pot for a rotationally fixed connection, and a plurality of axial recesses.The brake pot and the friction ring are then joined, with the brake pot being inserted axially through the friction ring in such a way that the external toothing and the internal toothing form a rotationally fixed connection and a plug-in element is guided axially through each recess from a first end face of the friction ring to the second end face of the friction ring. Each plug-in element has three legs that are connected to one another in one piece, with the first leg being designed to axially engage the first end face of the friction ring, the second leg being designed to be arranged in the respective recess on the brake pot, and the third leg being designed to axially engage the second end face of the friction ring. Finally, the brake pot and the friction ring are axially fixed by forming at least one end section, namely the third leg, of the respective plug-in element.

[0012] For example, the brake chamber is made of a steel material, in particular 35CrMn5. For example, the friction ring is made of cast iron with lamellar graphite, in particular EN-GJL-200 or EN-GJL-150.

[0013] According to one embodiment, at least three to a maximum of fourteen plug-in elements are formed substantially parallel to the outer circumferential surface of the brake pot. Preferably, at least four to a maximum of ten plug-in elements are formed substantially parallel to the outer circumferential surface of the brake pot. In particular, the plug-in elements on the brake pot, and thus also the recesses on the friction ring, are evenly distributed in the circumferential direction. This allows for uniform axial fixation. Substantially parallel to the outer circumferential surface of the brake pot means that the majority of the respective plug-in element extends parallel to the outer circumferential surface with a slight deviation of up to five degrees.

[0014] According to one embodiment, the plug-in elements are formed on a circumferential collar of the brake chamber. The collar extends radially outward and is provided as an axial stop surface for the friction ring. In particular, the friction ring rests axially on the collar all the way around.

[0015] According to one embodiment, the first leg and the third leg are formed substantially perpendicular to the second leg. In particular, the first leg and the third leg are formed substantially perpendicular to the outer peripheral surface of the brake pot. For example, the third leg is angled from the second leg in such a way that the resulting shape resembles a plug, in particular, it is T-shaped.

[0016] According to one embodiment, the friction ring has a circumferential recess on at least one of the two end faces in the region of the recesses. For example, the circumferential recess is arranged on the second end face. The brake chamber protrudes axially from the second end face and thus extends along a rotational axis. Alternatively or additionally, the circumferential recess is arranged on the first end face. In particular, the at least one recess is provided for improved ventilation of the friction ring.

[0017] According to one embodiment, each recess on the second end face of the friction ring has a pocket designed as a depression for receiving an end portion of the respective plug-in element. For example, an end portion of the respective plug-in element, in particular a free end of the respective plug-in element, is reshaped, in particular hot-stitched, crimped and / or folded, in such a way that at least one positive and / or non-positive connection for axial fixation is established. This reshaped end portion of the respective plug-in element comes into contact with the friction ring and forms the third leg of the plug-in element. If a pocket is formed on the respective recess, the reshaped material of the end portion of the respective plug-in element can be received in the pocket and thus does not protrude beyond the second end face of the friction ring.

[0018] A vehicle according to the invention comprises at least one two-part brake disc according to the invention. In particular, a two-part brake disc according to the invention is arranged on each vehicle wheel. The vehicle is preferably designed as a motor vehicle. The above definitions as well as statements regarding technical effects, advantages, and advantageous embodiments of the transmission according to the invention also apply mutatis mutandis to the drive unit according to the invention and the vehicle according to the invention.

[0019] Advantageous embodiments of the invention, which are explained below, are illustrated in the drawings, wherein identical or similar elements are provided with the same reference numerals. They show: Fig. 1 a highly abstracted schematic perspective view of a two-part brake disc according to the invention according to a first embodiment; Fig. 2 a detailed section of the two-part brake disc according to the first embodiment; Fig. 3 is an exploded view of the two-part brake disc according to the first embodiment; Fig. 4 a detailed section of the friction ring of the two-part brake disc according to the first embodiment; Fig. 5 a detailed section of the brake pot of the two-part brake disc according to the first embodiment; Fig. 6 a detailed section of the two-part brake disc according to the first embodiment; Fig. 7 a highly abstracted schematic perspective view of a two-part brake disc according to the invention according to a second embodiment; Fig. 8 a detail of the two-part brake disc according to the second embodiment; and Fig. 9 a highly abstracted schematic view of a vehicle with several two-part brake discs according to the invention.

[0020] Fig. 1 shows the two-part brake disc 1 according to the invention for a vehicle 100, which is Fig. 9. The two-part brake disc 1 consists of a brake chamber 2 and a friction ring 4. Fig. 2 shows a detailed section of the two-part brake disc 1 according to the invention from Fig. 1. The brake pot 2 is formed by forming from a steel sheet and has an external toothing 3 on an outer circumferential surface. The friction ring 4 is formed by primary forming from a gray cast iron and has an internal toothing 5 on an inner circumferential surface. The internal toothing 5 engages in a form-fitting manner in the external toothing 3 on the brake pot 2 for the rotationally fixed connection of the brake pot 2 and the friction ring 4, as shown in particular in Fig. 2 is clearly shown. The internal gearing 5 and the external gearing 3 are designed as splines and enable torque transmission between the brake pot 2 and the friction ring 4.

[0021] How particularly good Fig. 3, which shows an exploded view of the two-part brake disc 1, the friction ring 4 has a total of eight axial recesses 6. Furthermore, the brake pot 2 has a total of eight plug-in elements 7, of which only six plug-in elements 7 are visible due to the perspective view. In the assembled state of the two-part brake disc 1, the brake pot 2 is inserted axially through the friction ring 4 in such a way that the external toothing 3 and the internal toothing 5 form a rotationally fixed connection and a plug-in element 7 is guided axially through each recess 6 from a first end face of the friction ring 4 to the second end face of the friction ring 4. The brake pot 2 and the friction ring 4 are axially fixed by forming, in particular bending through 90°, an end section of the respective plug-in element 7 so that the respective end section comes to rest on the second end face of the friction ring.For example, the end section of the respective plug-in element 7 can be produced by hot-staking, crimping or folding.

[0022] Furthermore, the friction ring 4 has a circumferential recess 9 on the second end face in the region of the recesses 6, which is designed to improve the ventilation of the friction ring 4. When the two-part brake disc 1 is mounted on the vehicle, in particular on the vehicle wheel, the two-part brake disc 1, i.e. the brake chamber 2 and the friction ring 4, rotates about a common axis of rotation 11. The vehicle is decelerated when a braking torque is introduced at the friction ring 4 via brake shoes of a braking device (not shown in detail).

[0023] In Fig. Figure 4 shows a section of the friction ring 4 of the two-part brake disc 1, with the focus here being on the internal toothing 5, designed as a spline, and the recesses 6. The internal toothing 5 consists of radially formed teeth and tooth gaps arranged alternately in the circumferential direction. All recesses 6 are identically designed as angular openings, i.e., holes. The respective recess 6 extends axially through the entire friction ring 4, i.e., from the first end face to the second end face of the friction ring 4.

[0024] In Fig. Figure 5 shows a section of the brake chamber 2 of the two-part brake disc 1, with the focus here being on the external toothing 3 designed as a plug-in toothing and the plug-in elements 5. The external toothing 3 consists of radially formed teeth and tooth gaps that are arranged alternately in the circumferential direction. The teeth of the external toothing 3 are designed complementarily to the tooth gaps of the internal toothing 5, wherein the tooth gaps of the external toothing 3 are designed complementarily to the teeth of the internal toothing 5. All plug-in elements 7 are designed identically and are arranged on a circumferential collar 8 of the brake chamber 2. As can be seen particularly well from Fig. 6, the collar 8 is designed as an axial stop, with the first end face of the friction ring 4 coming into axial contact therewith. Each plug-in element 7 has three legs 7.1, 7.2, 7.3 connected to one another in one piece, with the first leg 7.1 being designed for axial contact with the first end face of the friction ring 4, with the second leg 7.2 being designed for arrangement in the respective recess 6 on the brake chamber 2, with the third leg 7.3 being designed for axial contact with the second end face of the friction ring 4. The third leg 7.3 is designed as the free end of the plug-in element 7 and, for the axial fixing of the friction ring 4 to the brake chamber 2, only comes into axial contact with the second end face of the friction ring 4 in the fully assembled state of the two-part brake disc 1, as can be seen from Fig. 6. The plug-in elements 7 are formed essentially parallel to the outer circumferential surface of the brake pot 2. As can be seen in particular from Fig. 6, the first leg 7.1 and the third leg 7.3 are formed substantially perpendicular to the second leg 7.2 and thus also perpendicular to the outer circumferential surface of the brake pot 2.

[0025] To manufacture the two-part brake disc 1, the brake chamber 2 and the friction ring 4 are first formed or prepared. The brake chamber 2 is formed by deep drawing from a steel sheet, with the external toothing 3 and several plug-in elements 7 being formed on the outer peripheral surface of the brake chamber 2. In particular, the plug-in elements 7 are formed by bending flat webs by 90° on the outer peripheral surface of the brake chamber 2, in this case on the collar 8. The friction ring 4 is formed by primary forming from a gray cast iron, with the internal toothing 5 and several axial recesses 6 being formed in the process. Thereafter, the brake pot 2 is inserted axially through the friction ring 4 in such a way that the external toothing 3 and the internal toothing 5 form a rotationally fixed connection and a plug-in element 7 of the brake pot 2 is guided axially through each recess 6 of the friction ring 4 from a first end face to the second end face of the friction ring 4.The axial fixation of the brake chamber 2 and the friction ring 4 is achieved by forming an end section of the respective plug-in element 7 and forming the third leg 7.3, which is essentially perpendicular to the second leg 7.2. Finally, a final fine adjustment or finishing of the two-piece brake disc 1 can be performed. This manufacturing process reduces production costs and assembly effort. In particular, it allows for the production of a lightweight yet robust two-piece brake disc 1.

[0026] Fig. 7 and Fig. 8 show a second embodiment of the two-part brake disc 1 according to the invention. The two-part brake disc 1 according to the second embodiment essentially corresponds to the two-part brake disc 1 according to the first embodiment. The difference between these two embodiments is the formation of pockets 10 in the region of the recesses 6 on the second end face of the friction ring 4 and the accommodation of the end section of the respective plug-in element 7, i.e., the third leg 7.3, in these pockets 10. In other words, the end section of the respective plug-in element 7 is formed in such a way that it essentially fills the recess of the pocket 10 and, in particular, does not protrude from the pocket 10. For example, the end section of the respective plug-in element 7 is essentially plug-shaped or T-shaped for particularly reliable and robust axial securing. This works particularly well Fig. 8 stands out.

[0027] Fig. Figure 9 shows a vehicle 100 with a first axle 101 with two vehicle wheels R1, R2 and a second axle 102 with two vehicle wheels R3, R4. In this case, the first axle 101 is designed as the rear axle of the vehicle 100. A drive unit 103 is arranged on the second axle 102, i.e., on the front axle of the vehicle 100, and is drivingly connected to the vehicle wheels R3, R4 of the second axle 102. A two-part brake disc 1 is arranged on each of the four vehicle wheels R1, R2, R3, R4 and is configured to brake the respective vehicle wheel R1, R2, R3, R4. Reference symbol 1 brake disc 2 brake pot 3 External gearing on the brake pot 4 friction ring 5 Internal teeth on the friction ring 6 recess 7 plug-in element 7.1 first leg of the plug-in element 7.2 second leg of the plug-in element 7.3 third leg of the plug-in element 8 collars 9 Deepening 10 bags 11 Rotation axis 100 vehicles 101 first axis 102 second axis 103 Drive motor R1 vehicle wheel R2 vehicle wheel R3 vehicle wheel R4 vehicle wheel

Claims

[1] A two-part brake disc (1) for a vehicle (100) comprising a brake chamber (2) formed by forming from a metal sheet and having an external toothing (3) on an outer circumferential surface, and a friction ring (4) formed by primary forming from a gray cast iron and having an internal toothing (5) on an inner circumferential surface, which engages in the external toothing (3) on the brake chamber (2) for a rotationally fixed connection, wherein the friction ring (4) has a plurality of axial recesses (6) and the brake chamber (2) has a plurality of plug-in elements (7), wherein each recess (6) receives a plug-in element (7) which extends from a first end face of the friction ring (4) through the respective recess (6) to the second end face of the friction ring (4) and is designed for the axial fixing of the friction ring (4) on the brake chamber (2), characterized bythat each plug-in element (7) has three legs (7.1, 7.2, 7.3) which are connected to one another in one piece, the first leg (7.1) being designed for axial engagement with the first end face of the friction ring (4), the second leg (7.2) being designed for arrangement in the respective recess (6) on the brake pot (2), the third leg (7.3) being designed for axial engagement with the second end face of the friction ring (4). [2] Brake disc (1) according to claim 1, wherein at least three to a maximum of fourteen plug-in elements (7) are formed substantially parallel to the outer peripheral surface of the brake pot (2). [3] Brake disc (1) according to one of the preceding claims, wherein the plug-in elements (7) are formed on a circumferential collar (8) of the brake pot (2). [4] Brake disc (1) according to one of the preceding claims, wherein the first leg (7.1) and the third leg (7.3) are formed substantially perpendicular to the second leg (7.2). [5] Brake disc (1) according to one of the preceding claims, wherein the friction ring (4) has a circumferential recess (9) on at least one of the two end faces in the region of the recesses (6). [6] Brake disc (1) according to one of the preceding claims, wherein each recess (6) on the second end face of the friction ring (4) has a pocket (10) designed as a depression for receiving an end portion of the respective plug-in element (7). [7] Method for producing a two-part brake disc (1) according to one of the preceding claims, comprising the method steps: • Forming a brake pot (2) by forming it from a metal sheet, wherein an external toothing (3) and a plurality of plug-in elements (7) are formed on an outer peripheral surface of the brake pot (2), • Forming a friction ring (4) by primary forming from a grey cast iron, wherein the friction ring (4) has an internal toothing (5) on an inner circumferential surface, which engages in the external toothing (3) on the brake pot (2) for rotationally fixed connection, and a plurality of axial recesses (6), • Joining the brake pot (2) and the friction ring (4), wherein the brake pot (2) is inserted axially through the friction ring (4) in such a way that the external toothing (3) and the internal toothing (5) form a rotationally fixed connection and a plug-in element (7) is guided axially through each recess (6) from a first end face of the friction ring (4) to the second end face of the friction ring (4), wherein each plug-in element (7) has three legs (7.1, 7.2, 7.3) connected to one another in one piece, wherein the first leg (7.1) is designed for axial contact with the first end face of the friction ring (4), wherein the second leg (7.2) is designed for arrangement in the respective recess (6) on the brake pot (2), wherein the third leg (7.3) is designed for axial contact with the second end face of the friction ring (4), • axially fixing the brake pot (2) and the friction ring (4) by forming at least the third leg (7.3) of the respective plug-in element (7). [8] Method according to claim 7, wherein the brake pot (2) with the external toothing (3) is formed by deep drawing the metal sheet and the plug elements (7) are formed by bending flat webs on the outer peripheral surface of the brake pot (2). [9] Vehicle (100) comprising at least one two-part brake disc (1) according to one of claims 1 to 6.

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