JPH0587341U - Wet friction plate - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To reduce the amount of friction material used and to reduce the cost of wet friction plates. [Structure] A friction material is segmentally fixed to the core plate. The total fixing area of the segment-shaped friction material is 1/4 or more and 4/5 or less of the area where the core plate 20 can be fixed. An oil groove is used between the segment-shaped friction members 34 and 36.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a wet friction plate used with a cooling liquid.

[0002]

[Prior Art]

 Conventionally, wet friction plates are manufactured by fixing (usually adhering) friction materials (various types such as those using paper as a base material and those using rubber as a base material) to the core plate. . In this case, it is natural that the friction material is arranged so as to cover almost the entire surface of the core plate. In order to provide a coolant (oil) flow path in such a wet friction plate, a grooved construction method, a wave construction method, or a method of arranging segment-shaped friction plates with an interval of 1.0 mm to 1.4 mm is used. However, even if there are grooves, waves, etc., there is no difference in the basic idea of arranging the friction material so as to cover almost the entire surface of the core plate.

[Background of the invention]

 However, when the behavior of oil on the friction surface is microscopically observed with a lubrication visual tester, uneven contact with the reaction plate and a cavity phenomenon due to cavitation occur on the surface of the friction material, and the entire area of the friction material does not necessarily work. It has been clarified that it is not doing.

[Device configuration]

 In consideration of the above facts, the present invention recognizes that it is not necessary to dispose the friction material so as to cover almost the entire surface of the core plate. The gist is that they are arranged so as to occupy 1/4 or more and 4/5 or less of the area where materials can be fixed. The number of segments may be 2 or more and 24 or less, and the material, shape, area, etc. of each segment of the friction material may be different from each other. Further, the arrangement is not particularly limited, including the front and back phases of the core plate. The gap between the segments thus configured can be used as a cooling oil flow path. Furthermore, if the end surface of the friction material is tapered, the formation of a squeeze oil film can be promoted. The friction material is often adhered to both surfaces of the core plate, but the above numerical values are, of course, per one surface of the core plate.

[Action]

 Although the details of what action the structure of the present invention produces are not clear, it is thought that the key to the wet friction plate is the interposition of an oil film. That is, since the friction plate is applied with torque while being pressed against the reaction plate, the cooling liquid (oil) interposed between them exerts pressure, that is, load capacity, by the so-called wedge film effect and squeeze film effect. It is thought that this causes the friction material to have a smaller surface area than the conventional one, but to fulfill the same function. Further, since there are many exposed core plates, the flow rate of the cooling liquid becomes large due to the arbitrary shape and arrangement of the friction material, which is disturbed, so that the cooling effect is promoted.

【Example】

 The first embodiment will be described with reference to FIG. 1. The segment friction material 30 is arranged on the core plate 20 of the friction plate 10 so that the friction materials are spaced at intervals of 45 degrees. In the case of the figure, the total area of each segment of the friction material is the area of the core plate where the friction material can be fixed (the area enclosed by the concentric circles obtained by extending the outer diameter and the inner diameter of the friction material along the circle). It becomes 1/2. The number of segments according to the present invention is preferably 2 or more and 24 or less, and the total area of each segment is preferably 1/4 or more and 4/5 or less of the friction material adherable area of the core plate. If the total area of the friction material is less than 1/4 of the area where the friction material can be fixed on the core plate, the load capacity is considered insufficient. Also, when this exceeds 4/5, there is no great difference from the conventional product. 2 to 4 show examples of other friction plates. The friction plate 12 of the second embodiment shown in FIG. 2 is such that, for example, a rectangular segment friction member 32 obtained from a roll material or a sheet material at a yield of 100% is arranged on the core plate 20. In the conventional friction plate, only the friction material formed into a fan shape was adhered according to the shape of the core plate, but according to the findings of the present invention, it is not necessary to form the friction material into a fan shape. A rectangular (or trapezoidal) shape is sufficient, and thus the yield of the friction material can be 100%. Further, in this manner, the exposure of the core plate around the friction material can be increased, and the cooling effect by heat transfer can be promoted. In the friction plate 14 of the third embodiment shown in FIG. 3, the first friction material 34 and the second friction material 36 are arranged on the core plate 20. The first friction material 34 and the second friction material 36 have different shapes, and the materials are the same or different. With such a configuration, multiple friction performances can be obtained. In the friction plate 16 of the fourth embodiment shown in FIG. 4, the friction material 38 is arranged on the core plate 20 so that the gaps between adjacent segments or the positions in the radial direction are different from each other, which promotes the turbulent flow of the cooling oil. The cooling effect is increased. 5 and 6 show still another embodiment. As shown in FIG. 5, when the end surface of the friction material 40 is adhered to the core plate 20 so as to have a taper (the angle is not particularly limited), formation of a squeeze oil film is promoted between the mating plates during operation. The tapered shape does not necessarily have to be formed on all the end faces of each segment, but it is desirable to form it on all the end faces. Further, FIG. 6 shows that the friction members 42 and 44 are arranged with the phases shifted on the front and back sides of the core plate 20. As described above, the friction material according to the present invention comprises 2 or more and 24 or less, preferably 3 to 10 segments, and each segment does not have to have the same material, the same shape, and the same area. , Can be placed at any position. In the friction plate used with the same pressing force regardless of the friction area, the product of the present invention inevitably receives a high surface pressure because it works on a small friction surface, but as described above, the shear force due to the load capacity of the oil film is applied. Since the torque is increased and the generated torque is received by this shearing force, there is no decrease in capacity. Further, there is no problem in the heat resistance of the friction material itself due to the cooling oil supplied from a wider gap than before. The friction plate of the present invention can be used not only in the multi-plate friction engagement device but also in the single-plate friction engagement device.

[Experimental example] Fig. 7 shows the friction area that can be fixed to the friction material on the core plate by 48% (first embodiment product), Fig. 8 by 64% (second embodiment product), and Fig. 9 by 100% (conventional product). It is the result of the durability test for the clutch facing with the material adhered, and the change in friction coefficient is expressed as a function of the number of cycles up to 10,000 cycles, and the amount of wear after the completion of the test is measured. Each test is shown by the average value of N (number of samples) = 2. From the results of this test, it can be seen that the wear amount of both of the implemented products is slightly higher than that of the conventional product. However, considering that the allowable wear amount in this durability test is 80 μm, the product of the present invention has Although it was higher than the conventional one, the same effect was obtained in terms of performance, and it was proved that the durability has no problem in use.

[Effect of the device]

 The amount of friction material used can be greatly reduced compared to the conventional one, resulting in cost reduction. Furthermore, the yield of the material can be made 100% by forming each segment into a square shape or the like. Since the exposed area of the core plate is large and the segments disturb the cooling liquid, the cooling effect is promoted. Composite friction performance can be realized by arranging segments made of different materials and different shapes on the same core plate.

[Brief description of drawings]

FIG. 1 is a plan view of a first embodiment.

FIG. 2 is a plan view of a second embodiment.

FIG. 3 is a plan view of a third embodiment.

FIG. 4 is a plan view of a fourth embodiment.

FIG. 5 is a cross-sectional view of another embodiment.

FIG. 6 is a sectional view of still another embodiment.

FIG. 7 is a graph showing a result of a durability test of the first embodiment product.

FIG. 8 is a graph showing a result of a durability test of a second embodiment product.

FIG. 9 is a graph showing a result of a durability test of a conventional product.

[Explanation of symbols]

10, 12, 14, 16 Friction plate 20 Core plate 30, 32, 34, 36, 38, 40, 42, 44 Friction material

Claims (6)

[Scope of utility model registration request] 1. A friction plate in which a plurality of segment-shaped friction members are fixed to a core plate, wherein the total area of the friction members is 1/4 or more of the area where the friction members can be fixed on the core plate.
A wet friction plate characterized by occupying 5 or less. 2. The wet friction plate according to claim 1, wherein the friction material is composed of 2 to 24 segments. 3. The wet friction plate according to claim 1 or 2, wherein the end surface of each segment of the friction material has a tapered shape. 4. The wet friction plate according to claim 1 or 2, wherein the segments include those having different shapes. 5. The wet friction plate according to claim 1 or 2, which includes those having different gaps or radial positions between the segments. 6. The wet friction plate according to claim 1 or 2, wherein the segments include those made of different materials.