JPS62110029A - Clutch facing - Google Patents

Abstract

PURPOSE:To improve the strength of the peripheral wall part of a rivet hole by making the composition ratio of a binder to a base material of the peripheral wall part of said rivet hole larger. CONSTITUTION:30% base material made of asbestos, 30% binder made of phenolic resin, 20% calcium carbonate as a friction adjusting agent, and 20% metal powder are well mixed and thermoformed for 3min using a metal mold consisting of an upper mold 2 having a projected part 21 and a lower mold 3 having a recessed part 31. Thereby, the composition ratio of a binder to a base material of the peripheral wall of a rivet hole becomes larger than the composition ratio of the binder to base material of the inside of a clutch facing base body, improving the strength of the peripheral wall part of the rivet hole.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to improvements in clutch facings for clutch disks used in automobiles and the like that connect and disconnect power transmission, and particularly relates to dry clutch facings with excellent burst strength.

[Prior Art] In automatic vehicles, clutch facings are used as parts of clutch discs that connect and disconnect power between an engine and a transmission. This clutch facing 1
Generally, it has a stringy donut shape as shown in Figure 2, and
As shown in the figure, it is attached to both sides of the disc spring 4 and is pressed against a mating member such as a pressure plate to transmit assistance. This clutch facing is made of inorganic fibers such as asbestos, carbon fibers, and glass fibers, or composite fibers of the inorganic fibers and organic fibers such as polyamide fibers, a thermosetting resin as a binder, a rubber material, and a processed material. Resin mold type products are known, which are formed by mixing a sulfur agent, a friction modifier, etc., injecting the mixture into a mold, and heating and pressurizing the mixture. In addition, this I! The material is impregnated with a mixed solution of binders such as thermosetting resin, rubber material, vulcanizing agent, and friction modifier. Cut this into an appropriate shape,
Woven type fabrics are formed by laminating them into a desired circular shape and then heating and pressurizing them.Also, the fibers are formed into a string shape, impregnated with a mixed solution containing a binder, and then spirally formed.
Alternatively, semi-mold type materials are also known, which are formed by rolling up the material into a thermoid shape, molding it into a desired shape, and heating and pressurizing it.

[Problems to be Solved by the Invention] In attaching clutch facings to both sides of a disc spring, as shown in FIG.
This is achieved by inserting a metal rivet into a rivet hole 11 coaxially communicating the clutch facing 1 and the disc spring 4 and caulking the metal rivet. In order to provide the rivet holes 11 in the clutch facing 1, after forming the clutch facing by thermoforming,
This was done by machining using a drill or the like.

By the way, one of the measures for evaluating the performance of clutch facing is burst strength. This burst strength is given by the rotation speed at which the clutch facing is rotated at high speed while gradually increasing the rotation speed until it breaks, and it is determined that the larger the value, the better the strength. It is also generally known that during this burst strength test, stress concentration acts on the rivet holes, causing failure starting from the rivet holes.

In conventional clutch facings, the rivet holes are formed by machining, so micro-cracks Jfi may occur on the peripheral wall surface of the rivet holes due to machining, and fibers may be exposed, causing stress concentration. It was easy.

The present invention has been made in view of this problem, and it is an object of the present invention to provide a clap facing that is even more immersed in burst strength.

[First Step to Solve the Problems] The clutch facing of the present invention has a substantially disc shape and is mainly composed of a base material such as asbestos and a binder such as a thermosetting resin, and has a shape that penetrates parallel to the axial direction. In a clutch facing that has a shear rivet hole and can be attached to a mounting member such as a clutch spring through the rivet hole, the composition ratio of the binder in the peripheral wall of the rivet hole to the base material is as follows: It is characterized in that the composition ratio of the binder inside the binder to the base material is greater than that of the base material.

The base material used for the clutch facing of the present invention includes asbestos, carbon m mt, N machine fibers such as glass fiber braid,
Or, it is composed of composite fibers made by mixing these inorganic fibers with polyamide fibers and fats.

Further, a small amount of metal fiber or the like can also be used together.

As a binder, phenolic resin, phenoxy T6
Thermosetting resins such as A1111, epoxy resins, and unsaturated polyester resins can be used.

Phenolic resin refers to a resin obtained by condensing one or more phenols such as phenol and cresol with formaldehyde or a compound that is a source thereof. Modified phenolic resins modified with cashew nut oil, polyvinyl butyral, vegetable oil, melamine, 1-boxy compounds, etc. may also be used. Note that unmodified phenol resin is good in terms of heat resistance.

Furthermore, in general, a relatively large amount of rubber is used together with a vulcanizing agent for clutch facings, and the amount of rubber used can be selected depending on the composition of raw materials, vJ, and usage.

Other ingredients include inorganic powders such as barium sulfate, diatomaceous earth, alumina, dolomite, calcium carbonate, calcium hydroxide, and graphite, organic powders such as cashew dust and rubber dust, and metal powders such as aluminum, iron, and zinc. I9! l! ! ! Modifiers can also be used.

The clutch facing of the present invention is formed into a substantially disk shape from the above-mentioned raw materials.

For example, resin mold type products are made by mixing a base material and a binder and press-molding the mixture using a mold, or the above-mentioned fibers are made into a felt, mat, or woven fabric and impregnated with a mixed solution containing a binder, etc. Either a woven material is used, in which a silk-like base material is impregnated with a mixed solution, rolled up 11 times, preformed, and then aged in a semi-molded material.

The greatest feature of the present invention lies in the configuration of the rivet holes. The rivet holes are provided in parallel to the axial direction and are exposed in a uniform plane from the surface of the clutch facing.

Generally, a plurality of them are provided along the peripheral edge of the clutch facing.

In the peripheral wall of the rivet hole, the composition ratio of the binder to the base material is larger than in the inside of the clutch facing. Here, it is desirable that the composition ratio of the binder to the base material in the peripheral wall of the rivet hole is 1.4 to 7.

If this ratio is smaller than 1.degree. 4, the burst strength cannot be expected to increase much, and if it is larger than 7, the friction characteristics and the holding strength by the rivet will be poor. The composition ratio of the binder to the base material is preferably such that the peripheral wall of the rivet hole is 1.4 to 7 times larger than the inside of the clutch facing base. Within this range, burst strength is excellent and frictional properties are maintained sufficiently.

To do this, for example, for woven clutch facings, two types of base materials with different amounts of binder impregnated are prepared, and during preforming, the parts surrounding the rivet holes are filled with the base material with a higher amount of binder impregnated. This can be achieved by placing materials. However, in this case, the number of man-hours increases, and drilling by machining may sometimes cause minute cracks.

In order to eliminate such problems, it is desirable to form the rivet holes at the same time as the clutch facing is thermoformed. Conventionally, it is known that in thermoformed clutch facings, the composition of the surface part where heat is most transmitted is higher in binder component than the composition of the inner part. Therefore, it is effective to actively utilize this effect on the peripheral wall of the rivet hole. If the raw materials are appropriately selected and the rivet holes are formed using this method, the composition ratio of the rivet hole peripheral wall will satisfy the above ranges.

To form a rivet hole in this way, for example, in a resin mold system, a convex part to form a rivet hole in the mold,
13 and a recess, respectively.

Furthermore, woven and semi-molded types can be formed by providing a convex portion and four portions on two heating plates that sandwich the preform during thermoforming. If you do it like this,
During thermoforming, rivets 1 to holes are simultaneously formed, and the heat during thermoforming is applied to the peripheral wall surface of the rivet hole as well as both surfaces of the clutch facing. 3. Therefore, the composition of the peripheral wall of the rivet hole is almost the same as that of both surfaces of the clutch facing, and has a larger binder component than the inside of the clutch facing.

[Operation J3 and Effects of the Invention] In the clutch facing of the present invention, the composition ratio between the binder and the base material in the peripheral wall of the rivet hole is larger than the composition ratio between the binder and the base material inside the clutch facing base. ing. Therefore, the strength of the peripheral wall of the rivet hole is improved, resulting in excellent burst strength. In addition, most parts of the clutch facing have the same composition as conventional ones,
The friction characteristics are almost the same as before. Furthermore, if the rivet holes are formed at the same time as the thermoforming, the machining of the holes can be omitted, reducing the number of man-hours and preventing the occurrence of minute cracks on the peripheral wall of the rivet holes. This results in even better burst strength.

[Example] The following is a concrete explanation using Examples. Note that the percentages described below mean multilayer percentages unless otherwise stated.

(Example) 30% base material made of asbestos, 30% binder made of phenolic resin, 20% calcium carbonate as a friction modifier, and 20% metal powder (brass powder) were thoroughly mixed, As shown in FIG. 1, the upper mold 2 has a protrusion 21.
and a lower mold 3 having a recess 31.
Thermoforming was carried out for 3 minutes at 0°C and a pressure of 110K (1 cm). (As shown in Figure 2, the molded product had multiple rivet holes 11 with an inner diameter of 6IllIll, It was a donut-shaped resin molded clutch facing 1 with a diameter of 224 + 11111.inner diameter 1 (3Q mm).

The composition of the inside of this clutch facing 1 and the peripheral wall of the rivet hole 11 was measured by fluorescent X-ray analysis, and the results are shown in the table.

(Conventional Example) Except for using a mold that does not have a mold surface for forming rivet holes, the same raw materials as in the example were used, and the molded product without rivet holes was obtained by thermoforming under the same conditions. Ta. Next, a 6φ rivet hole was drilled in this molded body, and a clutch facing having the same shape as the example was manufactured. The composition of the inside of the clutch facing and the peripheral wall of the rivet hole of this conventional example was measured in the same manner as in the example, and the results are shown in the table.

(Test Example) The burst strength was measured for each of the above two types of clutch facings. As a result, the number of rotations at which the clutch facing was destroyed was 1670 Orp in the example.
m, that of the conventional example was 1500 Orpm, and the clutch facing of the embodiment of the present invention had improved burst strength by about 10% compared to the conventional clutch facing.

(Evaluation) It is clear from the table that there are more organic matter (binder) stones in the peripheral wall of the rivet hole of the clutch facing of the example than in the inside. Further, in the conventional clutch facing, the inner wall portion of the rivet hole and the inside have the same composition. Therefore, it is clear that the difference in strength of the clutch facing of the embodiment is due to the composition of the peripheral wall of the rivet hole.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing thermoforming of a clutch facing according to an embodiment of the present invention, and FIG. 2 is a perspective view of clutch facings according to an embodiment and a conventional example. FIG. 3 is a cross-sectional view showing the clap facing attached to the tardage disk. 1...Clutch facing 11...Rivet hole 2...Upper mold 21...Protrusion 3...Lower mold 31...Fourth part 4...Clutch spring Fig. 1

Claims (4)

[Claims] (1) It has an approximately disk shape and is mainly composed of a base material such as asbestos and a binder such as a thermosetting resin, and has rivet holes that penetrate parallel to the axial direction, through which clutch springs, etc. can be attached. In a clutch facing that can be attached to a member, the composition ratio of the binder to the base material in the peripheral wall of the rivet hole is larger than the composition ratio of the binder to the base material inside the clutch facing base body. A clutch facing featuring (2) The clutch facing according to claim 1, wherein the rivet holes are formed during thermoforming of the clutch facing. (3) The clutch facing according to claim 1, wherein the composition ratio of the binder to the base material in the peripheral wall of the rivet hole is 1.4 to 7. (4) The clutch facing according to claim 1, wherein the composition ratio of the binder to the base material is 1.4 to 7 times larger in the peripheral wall of the rivet hole than in the inside of the clutch facing base.