Friction pads, friction plates, and processes for manufacturing friction plates

Abstract

The present invention relates to a friction pad (5) having a fastening surface and a friction surface (9) facing away from the fastening surface and having a shape defined by a peripheral cutting edge (11). To improve the function of the friction pad (5), the friction pad (5) includes a base rim (12) extending along the peripheral cutting edge (11) and is more compressed than the friction pad (5) within the base rim (12).

Description

[Technical Field]

[0001] The present invention relates to a friction pad having a fastening surface and a friction surface facing away from the fastening surface and having a shape defined by a peripheral cutting edge. The present invention also relates to a friction plate having at least one such friction pad. The present invention also relates to a process for manufacturing such a friction plate. [Background technology]

[0002] German Patent Application No. 102017124330 discloses a wet-running multi-plate clutch having clutch plates connected non-rotatably but axially displaceably to a plate carrier having fluid passage openings, at least one of the clutch plates having at least one radially inward and / or radially outward recess that improves the flow rate through a nearby fluid passage opening in one of the plate carriers.German Patent Application No. 102013010651 discloses a wet clutch arrangement having a closed clutch housing and at least one clutch plate arranged in the clutch housing, the clutch housing having a plate carrier and at least two friction pads arranged on the plate carrier, the friction pads being spaced apart from one another in the circumferential direction and defining coolant ducts that extend at least substantially radially and are inclined in the circumferential direction in at least partial regions. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE INVENTION An object of the present invention is to provide an improved friction pad having a fastening surface and a friction surface facing away from the fastening surface and having a shape defined by a peripheral cutting edge. [Means for solving the problem]

[0004] This object is achieved by a friction pad having a fastening surface and a friction surface facing away from the fastening surface and having a shape defined by a peripheral cut edge, the friction pad having a base rim extending along the peripheral cut edge and being more compressed than the friction pad within the base rim. The friction pad is preferably formed from a friction lining material containing fibers. Friction lining materials with fibers are similar to the raw materials used in papermaking. Therefore, the friction lining material is also called paper material, or simply paper. During operation, the friction pad is contacted with a coolant such as oil. Therefore, the friction pad is also called a wet-running friction pad. Similarly, the paper from which the friction pad is formed is also called wet-running paper. The friction pad is separated from the friction lining material along its cut edge, for example, by perforation. However, the friction pad can also be cut out of the friction lining material in some other way. During cutting or perforation, for example, using inexpensive tools, the friction pad may tear or the fibers may be torn out of the wet-running paper. When a part and / or fiber of the friction pad attached to the carrier element separates, this is also called delamination. Due to the more strongly compressed base rim of the friction pad, delamination during operation of the friction plate equipped with the friction pad can be substantially prevented or at least significantly reduced. The strength of the friction pad is substantially increased because the damaged area on the cutting edge is reinforced and defect-free by the overall embossing. In addition, drag torque can be reduced during operation of the friction plate equipped with the friction pad, since it is the embossed rounded edge that comes into contact with, for example, a steel plate, rather than the fibrous cutting edge. In accordance with this configuration, the base area of ​​the friction pad can be enlarged by the base rim in a known manner.

[0005] A preferred exemplary embodiment of the friction pad is characterized in that the base rim has a base height that corresponds to at least one-fourth of the pad height of the friction pad. The dimensions of the friction pad in the direction transverse to the fastening or friction surface are referred to as the pad height and the base height, where the fastening surface is arranged parallel to the friction surface. The claimed base height also allows the friction pad to be attached to the carrier element in a sufficiently stable manner in the region of the base rim.

[0006] Another preferred exemplary embodiment of the friction pad is characterized in that the base rim has a base width at least as large as the pad height of the friction pad. The dimension of the base rim in the direction transverse to the cutting edge is referred to as width. Due to the claimed base width, a sufficiently stable attachment of the friction pad can also be ensured in the region of the base rim on the carrier plate.

[0007] A further preferred exemplary embodiment of the friction pad is characterized in that the base rim is configured as a peripheral step, which in cross section has a first leg angled from the friction surface, from which a second leg is angled, the second leg representing the base rim. Thus, for example, the cutting edge generated when drilling the friction pad is angled from the end of the second leg facing away from the first leg. The shape of the friction pad can be implemented in almost any way. The peripheral step extends along the entire cutting edge on the friction pad.

[0008] Another preferred exemplary embodiment of the friction pad is characterized in that the angle between the friction surface and the first leg, as well as the angle between the first leg and the second leg, is between 90 and 120 degrees, which proves to be beneficial with regard to the desired functionality and with regard to the manufacture of the friction pad and the friction plate with the friction pad.

[0009] Another preferred exemplary embodiment of the friction pad is characterized in that a radius of curvature is formed between the friction surface and the first leg. This provides, among other things, the advantage that no fibrous cutting edges or sharp edges occur in the contact area or contact surface between the friction pad and the steel plate that comes into contact during operation of the friction plate and the friction clutch that includes the friction pad. As a result, wear of the friction pad during operation of the friction clutch, in particular a multi-plate clutch, can be substantially reduced.

[0010] Another preferred exemplary embodiment of the friction pad is characterized in that a radius of curvature is formed between the first and second legs, which has proven to be beneficial for the coolant flowing around the friction pad.

[0011] Another preferred exemplary embodiment of the friction pad is characterized in that the radius of curvature has a size of between one tenth and one millimeter, the claimed size of the radius of curvature advantageously relating to the radius of curvature between the friction surface and the first leg and between the first leg and the second leg.

[0012] The invention further relates to a friction plate having at least one friction pad as described above. The friction plate preferably comprises a carrier plate to which a plurality of friction pads as described above are adhered. Advantageously, all friction pads have a base rim. However, it is also possible that only some, i.e. not all, of the friction pads of the friction plate have a base rim.

[0013] In the process for manufacturing the friction plate described above, the above-mentioned object can alternatively or additionally be achieved by punching an intermediate pad product from the covering material in a punching process, then bonding the punched intermediate pad product to a carrier element in a subsequent bonding process, and embossing a base rim on the intermediate pad product during the bonding process. Fibers may be pulled out of the perforations at the cut edges, which is undesirable in itself because it results in pre-damage to the friction pad. By embossing the base edge, the pre-damaged area is advantageously compressed to the extent that open areas on or within the cut edges of the friction pad are closed. Due to the peripheral embossing created during bonding, the friction lining material, particularly the wet running paper, is significantly compressed or compressed in the areas damaged during perforation, increasing the strength of the friction pad on the carrier element. This results in an embossed contour without sharp cut edges on the contact surface or side of the friction pad that contacts the steel plate during operation. In this way, torque can be substantially reduced, while simultaneously lowering the risk of delamination. Among other things, the claimed solution offers the advantage that the groove pattern or groove configuration can be realized with smaller friction pads.

[0014] Further advantages, features and details of the invention will become apparent from the following description in which various exemplary embodiments are set forth in detail with reference to the drawings. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 shows a perspective view of a friction plate having a carrier element to which a friction pad having an embossed base rim is fastened. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] 1 shows a perspective representation of a friction plate 1 with a carrier element 2. The carrier element 2 has the shape of an annular disc. Radially inward, the carrier element 2 has internal toothing 3.

[0017] Internal toothing 3 on the carrier element 2 is used to provide a non-rotating connection with a plate carrier (not shown in FIG. 1 ), the multi-plate clutch of which has alternating friction plates 1 and steel plates, the steel plates being in frictional contact with the friction plates 1 to transmit torque. The structure and function of such a multi-plate clutch is known.

[0018] Friction pads 4, 5, 6, 7, 8 are attached to the carrier element 2. The friction pads 4 to 8 all have the same pentagonal shape. The friction pads 4 to 8 are arranged in two rows. The friction pads 4 to 8 are advantageously arranged in the same or similar manner as in WO 2018 / 171834 and WO 2018 / 171835.

[0019] The friction pad 5 has a friction surface 9 located at the top in Figure 1. The friction pad 5 is glued to the carrier element 2 with the fastening surface 10 facing away from the friction surface 9. The friction pad 5 is a perforated paper-like friction lining material.

[0020] The cutting edge 11 created during drilling defines, for example, the pentagonal shape of the friction pad 5. The friction pad 5 has a base rim 12 along the cutting edge 11. In the region of the base rim 12, the friction pad 5 is more compressed than inside the base rim 12.

[0021] Figure 2 shows an enlarged cross-sectional view taken along line II-II of Figure 1. The base height is indicated by double-headed arrow 13 in the cross-sectional view of Figure 2. The pad height is indicated by double-headed arrow 14. The base width is indicated by double-headed arrow 15.

[0022] The pad height 14 is significantly greater than the base height 13 in the region of the base rim 12 which is more compressed. The friction pad 5 has a circumferential step which represents the base rim 12 when viewed in cross section.

[0023] The step includes a first leg 16 that is angled from the friction surface 9. A second leg 17 is angled from the first leg 16. The second leg 17 serves to represent the base rim 12. The cutting edge 11 is also angled from the second leg 17.

[0024] The friction surface 9 is arranged parallel to the base rim 12. The second leg 17 is arranged parallel to the cutting edge 11 when viewed in the cross section shown. A right angle is formed between the friction surface 9 and the first leg 16. A right angle is also formed between the two legs 16, 17.

[0025] A radius of curvature 18 is provided between the friction surface 9 and the first leg 16. A radius of curvature 19 is provided between the first leg 16 and the second leg 17. [Explanation of symbols]

[0026] 1 friction plate 2. Career Elements 3 Internal teeth 4 friction pads 5 friction pads 6 friction pads 7 friction pads 8 friction pads 9 Friction surface 10 Fastening Surface 11 Cutting edge 12 Base rim 13 Base Height 14 Pad height 15 base width 16 First Leg 17 Second Leg 18 radius of curvature 19 Radius of curvature

Claims

1. A process for manufacturing a friction plate (1), comprising:

1. A process for forming a friction pad (5) by a stamping process from a lining material, the process comprising: forming an intermediate pad product made of paper material, the intermediate pad product having a fastening surface (10) and a friction surface (9) facing away from the fastening surface (10) and having a shape defined by a peripheral cut edge (11); and during a bonding process of bonding the stamped intermediate pad product to a carrier element (2), forming by embossing a base rim (12) extending along the peripheral cut edge (11) and being more compressed than the friction surface (9) on its inner side, thereby forming a friction pad (5).

2. 2. The process according to claim 1, characterized in that the base rim (12) has a base height (13) corresponding to at least one-fourth of the pad height (14) of the friction pad (5).

3. 3. The process according to claim 2, characterized in that the base rim (12) has a base width (15) at least as large as the pad height (14) of the friction pad (5).

4. 4. The process according to claim 1, wherein the base rim (12) is configured as a peripheral step, which in cross section has a first leg (16) angled from the friction surface (9), from which a second leg (17) is angled, the second leg (17) representing the base rim (12).

5. 5. The process according to claim 4, characterized in that the angle between the friction surface (9) and the first leg (16) and the angle between the first leg (16) and the second leg (17) are configured as angles between 90 and 120 degrees.

6. 6. A process according to claim 4 or 5, characterized in that a radius of curvature (18) is formed between the friction surface (9) and the first leg (16).

7. A process according to any one of claims 4 to 6, characterized in that a radius of curvature (19) is formed between the first leg (16) and the second leg (17).

8. A process according to claim 6 or 7, characterized in that the radii of curvature (18, 19) have a size between one tenth and one millimeter.

9. A process according to any one of claims 1 to 8, characterized in that the intermediate padding product is formed by being punched out of a lining material in a punching process.

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