JPH034780B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a facing material used primarily for a clutch disk of a dry clutch. [Prior Art] Dry clutches are interposed between the engine and transmission gears in automobiles equipped with manual transmission gears, etc., and provide intermittent driving force. It has an abutting pressure plate and a flywheel. The clutch disk has a structure in which clutch facings are fixed to both sides of a metal center plate. Conventional clutch facings use asbestos strings impregnated with binding resin, coated with various additives, and then rolled into a disk shape. However, since reports emerged that asbestos is harmful to the human body, research into clutch facing materials that do not contain asbestos has been underway. For example, Japanese Patent Application Laid-Open No. 57-85876 describes clutch facing materials containing 3 to 60% inorganic fibers other than asbestos, 5 to 50% vegetable fibers and organic synthetic resins.
%, friction performance improver 5-40%, inorganic matter 3-50%
%, metal powder 5 to 50%, and binder 5 to 25% are mixed in a Henshil mixer, etc., press-formed into a preliminary shape, and then completed through thermoforming, heat treatment, and polishing processes. An asbestos-based friction material is disclosed. [Problems to be Solved by the Invention] However, since the clutch facing material disclosed in the above-mentioned publication is a molded type friction material, it has a drawback of insufficient burst strength. The present invention was made in view of the above-mentioned conventional clutch facing materials, and it does not contain asbestos and has high burst strength and excellent properties suitable for use in high-speed, high-output vehicles. The present invention provides a clutch facing material. [Means for Solving the Problems] In order to solve the above problems, the clutch facing material to which the present invention is applied contains at least 15 to 40 parts by weight of aromatic polyamide fibers and 10 to 40 parts by weight of rock fibers.
A base material containing a friction modifier in which parts by weight of short glass fibers, 5 to 20 parts by weight of short glass fibers, and 15 to 25 parts by weight of long glass fibers are twisted together is impregnated with a thermosetting resin. The above-mentioned rock fibers can have a fiber diameter of about 3 to 8 μm and an average fiber length of about 30 mm. The long glass fibers have a fiber diameter of about 3 to 11 μm, and are continuous fibers in an elongated state that has not been bulked as they are spun. The shapes of other fiber components (aromatic polyamide fibers, short glass fibers), etc. are arbitrary. Friction modifiers include, for example, cashew dust, fillers, diatomaceous earth, potassium titanate, barium sulfate, calcium carbonate, silica powder, and the like. Thermosetting resins include, for example, phenolic resins, modified (melamine modified, oil modified, cashew modified, etc.)
Phenol resin, epoxy resin, and melamine resin can be used. For each of the above weight ratios, if the amount of aromatic polyamide fiber is small, the abrasion resistance and burst strength will be poor.
If there is too much, the specific gravity will be reduced, but it will be expensive. If there are too few rock fibers, wear will increase and at the same time the coefficient of friction at high temperatures will decrease.On the other hand, if there are too many rock fibers, although it is cheap, the specific gravity will increase and the burst strength will decrease.
If there is too little glass short fiber, wear will increase and the coefficient of friction at high temperatures will decrease; if there is too much, the specific gravity will increase and the burst strength will decrease. Furthermore, if there is too little long glass fiber, the burst strength will decrease and problems with string breakage will occur during the manufacturing process, while if there is too much, the specific gravity will increase and at the same time the coefficient of friction at low temperatures will become too high. In addition, you can optionally use wire diameters such as wire, metal wire (e.g. brass, copper wire, aluminum wire, zinc wire, steel wire, stainless steel wire, etc.)
A continuous length of 120 to 150 μm) can be mixed. If there is a large amount of cotton, it will be cheaper, but it tends to lack heat resistance. If the number of metal wires is too small, the burst strength will be reduced, as well as the heat dissipation property will be reduced and wear will increase, and if there are too many metal wires, the specific gravity will become large. [Function] The clutch facing material of the present invention has the above-mentioned components that improve wear resistance (life), burst strength,
Contributes to stabilizing the coefficient of friction and increasing the tensile strength of the base material. In particular, aromatic polyamide fibers, rock fibers, short glass fibers, and long glass fibers are effective for improving wear resistance. Aromatic polyamide fibers and long glass fibers are effective in improving burst strength. The coefficient of friction is stable up to about 500℃, and aromatic polyamide fibers, rock fibers, short glass fibers, and long glass fibers are effective. In particular, rock fibers, short glass fibers, and long glass fibers effectively contribute to stabilizing the coefficient of friction at 400 to 500°C. Furthermore, long glass fibers are effective in increasing the tensile strength of the base material. [Example] Hereinafter, specific examples of clutch facing materials will be described in detail. Examples 1 to 5 are typical examples to which the present invention is applied, and Comparative Examples 1 to 8 are examples to which the present invention is not applied. Tables 1 and 2 show the blending ratio (% by weight) of the base material (sliver) in each example. Tables 3 and 4 also show the performance of clutch facings made from the base materials of each example. The base materials of the clutch facing materials of Examples 1 to 5 of the present invention are obtained using the raw materials in Table 1, and the base materials of the clutch facing materials of Comparative Examples 1 to 8 are obtained using the raw materials of Table 2. The method will be explained with reference to FIG. First, aromatic polyamide fiber, Cotton,
Short fiber components such as short glass fibers are uniformly mixed and then continuous, and cashew dust and filler are mixed in to form a thin sliver 1. The sliver 1 and the unbulked long glass fibers 2 are twisted together in a Z twist to obtain a single yarn A. Further, the sliver 1, the long glass fiber 2, and the metal wire 3 are twisted together in the same Z-twist to obtain a single yarn B. Next, add 2 pieces of single yarn A.
By twisting the book and one single yarn B into an S twist, a doubled yarn string (base material) 5 is obtained. This doubling string 5 is impregnated with a thermosetting resin (modified phenolic resin) and then heated (120 to 135°C, 5°C).
Pre-dry for 1 minute) and roll into a disk. The clutch facing is obtained by heat-pressing, heat-treating, polishing, and drilling the necessary holes.

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〔Effect of the invention〕

As explained above, the clutch facing material to which the present invention is applied has a reduced wear rate, has a long life, and has high burst strength. Furthermore, the coefficient of friction is stable from low to high temperatures. Performance is well balanced overall. In particular, because the base material has a high tensile strength, problems due to string breakage do not occur during the manufacturing process of clutch facings. Therefore, a clutch using the clutch facing material of the present invention is most suitable for use in high-speed, high-output vehicles. Moreover, it is easy to manufacture,
Mass production becomes possible at low cost.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating a method for manufacturing a base material of a clutch facing material. 1...Sliver, 2...Long glass fiber, 3...
Metal wire, 5... Doubling string, A, B... Single thread.

Claims (1)

[Claims] 1 At least 15 to 40 parts by weight of aromatic polyamide fiber, 10 to 40 parts by weight of rock fiber, and 5 to 20 parts by weight of short glass fiber.
1. A clutch facing material characterized in that a thermosetting resin is impregnated into a base material containing a friction modifier made by twisting parts by weight of long glass fibers and 15 to 25 parts by weight of long glass fibers.