KR920008193B1 - Method for fabricating clutch facing of nonasbestos system - Google Patents

Abstract

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Description

Manufacturing method of non-asbestos clutch facing

1A to 1D are schematic views for winding and shaping a friction material during a clutch facing manufacturing process.

Figure 2 is a graph of the test results showing the results of the comparative test by the constant speed friction test of the conventional asbestos clutch facing and the clutch facing according to the present invention.

The present invention relates to a method for manufacturing a non-asbestos clutch facing for delivering engine power for passenger cars and industrial vehicles.

Conventionally, such a clutch facing is made by adding cotton yarn to asbestos fibers which are not bag-like and spinning it to make a thick thread, and weaving this thick thread into a tape or twisting this thick thread together with a brass wire and gathering them in parallel. The tape is squeezed and immersed in a thermosetting resin liquid and dried, and immersed in a rubber liquid, and rubber is attached to the surface of the tape to dry. Then, the product was wound into a mold, heated, pressurized, vulcanized and finished to a predetermined thickness, or a product was made in the same manner using glass fiber instead of asbestos.

In the case of such products, as the former is used asbestos harmful to the human body and the latter uses glass fiber, the whole product is greatly distorted when the product is produced, tending to roughen the counterpart metal surface, which yields poor performance and friction. In addition, because of the glass fiber, the glass fiber was broken during handling during the manufacturing process, making it difficult to stab the worker.

The present invention eliminates these drawbacks and provides a formulation of the non-asbestos-based clutch facings that is better in performance and easier to manufacture, and a method of manufacturing the same.

The present invention is based on the following formulation and preparation method.

(1) fire retardant fibers and

20 to 70% by weight of fiber yarn or woven fabric blended with aromatic polyamide fibers

(2) 5-30% by weight of thermosetting resin

(3) 20 to 60% by weight of rubber

First, the yarn or woven fabric of 1 is manufactured by the following method.

Flame-retardant cotton or rayon yarns are kneaded with aromatic polyamide fibers and then woven into a yarn or tape (or cut into tape with a wide width), soaked in a thermosetting resin solution and dried in a rubber solution. It is dipped and dried by attaching rubber to the surface of yarn or woven fabric. In the case of a tape, it is wound in the shape of a clutch facing in the form of a vortex (Fig. 1a), or in the same manner as in the case of a seal, or wound in the form of a clutch facing, or a coil slightly smaller than the width of the clutch facing, to form a clutch facing shape. It is a manufacturing method in which a friction surface is ground to a predetermined thickness after a predetermined heat treatment time has elapsed by crushing it in a transverse direction, stacking a plurality of layers according to the product thickness, heating, pressing, and shaping. When the yarn is wound onto the coil with a clutch facing width, it may be wound larger depending on the type of clutch facing but as opposed to the case where the yarn is wound smaller than that. FIG. 1 (b) shows the coils wound and FIG. 1 (c) shows them pulled out and crushed.

First, in the composition 1, cotton or rayon is used, but it is necessary to perform flame retardant treatment. There are various methods of flame retardant treatment, but there are known methods of impregnating boric acid borax and the like followed by drying to perform flame retardant processing, or immersion in an aqueous amide phosphene solution, followed by drying and heat treatment.

Here, the use of cotton or rayon as a real material is changed to a coagulation product having heat resistance but viscousity due to frictional heat when other organic fibers such as polyester are used. Cotton and rayon were selected for the purpose of using a fibrous material which is easy to be carbonized. That is, any fiber can be used as long as it is carbonized without being plasticized by heat.

Examples of the aromatic polyamide fibers include Kevlar® Noomex® (trademark of DuPont, USA) and Cornones® (trademark of Teijin, Japan). Although any of these fibers may be used, the thickness of the yarn is preferably 20 or less.

Cotton or rayon and aromatic polyamide fibers subjected to the above flame retardant treatment are twisted. The method of twisting may be either right twisted yarns or left twisted yarns, and the number of twists is preferably three times or less per cm.

This thread may be sent as it is to the next process, or weaving a slightly coarse woven fabric with a warp per weft, less than 10 rows of wefts together, or a tape-like fabric about 1 cm wide. Moreover, you may mix a metal wire at the time of continuous shooting. The metal wires include copper wires, brass wires, aluminum wires, and the like, and any metal wires may be used.

Although a phenol type is generally used as a thermosetting resin, the modified resin of this resin is also used, but a liquid resin is preferable. Moreover, although not limited to a phenol resin, you may use an epoxy resin, a melamine resin, or these mixed resin, but a thermoplastic resin is not preferable.

As the rubber, many N.B.R-based rubbers having good heat resistance may be used. Depending on the conditions of use, S.B.R. may be used, or acrylic rubber, silicone rubber or fluorine rubber may be used.

Sulfur is often used as a rubber vulcanizing agent as a rubber additive, but a peroxide or polyol vulcanizing agent may be used. In addition, carbon black may use any particle size. In addition, anti-aging agents, vulcanization accelerators and the like are mixed. As a friction improving agent, kashshudst and rubberdst are mixed in the rubber. In addition, depending on the required frictional performance, an inorganic powder having a Mohs hardness of 7 or less or a whisker-like inorganic fiber may be mixed in the rubber material. Representative examples of the inorganic powder or the inorganic fiber include wortite, potassium titanate fiber, magnesium carbonate and calcium carbonate, and a small amount of aluminum oxide may be incorporated.

Toluene is used a lot as a rubbery solvent.

In the manufacturing method, a woven fabric of thread or foot is immersed in a thermosetting resin solution and then dried. The resin liquid at this time has a specific gravity of 1 or less, and preferably 0.9 or less.

The rubber liquid is mixed with various fillers in accordance with the required friction performance as described above, immersed in a rubber liquid of 30% or less of the rubber powder, and then dried. After drying, it is wound as shown in FIG. 1 (a). In Fig. 1 (a), 1 denotes a thread or tape-like fiber infiltrated with a resin and rubber is attached, 2 denotes an inner diameter of the clutch facing, 3 denotes an outer diameter, and as shown in Fig. 1 (b), The core is wound in a spherical shape, and then the core is removed and crushed into a flat plane as shown in FIG. 1 (c), and pushed into a clutch mold as shown in FIG. Nest the.

Next, pressurized heating shaping is performed for several minutes at a surface pressure of 50 kg / cm 2 or more in a temperature range of 150 ° to 170 °. This is taken out, and it heats at 140 degreeC-190 degreeC for 30 to 300 minutes, grinds to predetermined thickness, and forms it.

Example 1

1. Make one thick thread by twisting the No. 20 cotton yarn, No. 10 Conex fiber and brass wire which were flame retarded by service. This is infiltrated into a phenol resin solution having a specific gravity of 0.85, which is a thermosetting resin solution, and dried. The infiltration rate was 26%.

2. This resin impregnated yarn is dipped in the rubber solution of the following formulation and dried.

100 parts of NBR rubber

20 parts of carbon black

Sulfur 8

Barium Sulfate Part 30

Cashew Dust Part 20

Vulcanization accelerator 1 part

Antioxidant Part 1

These were dissolved in a toluene solution to make a 20% solution. The adhesion amount of the said rubber compounding agent was 46%.

3. Wind this thread as shown in FIG.

Example 2

In the same process as in Example 1, the rubber-coated yarn was wound as shown in FIG. 1 (d), and the subsequent steps were carried out as in Example 1.

Example 3

The same thread as in Example 1 was made of the fabric on the following tape.

3 incl./10mm

Weft 3 book / 10mm

This tape was infiltrated into the resin liquid as in Example 1, and then the rubber liquid was attached, heat-pressurized, heat-treated and cut to make a product.

The product of the present invention thus produced was subjected to a comparative test by performing a constant friction test with a test piece like a conventional asbestos product.

The test results are the same as those in FIG. 2, and compared with the conventional asbestos clutch facings, the friction coefficient at high temperature is reduced, the wear rate is low, and the good results are obtained.

Claims (4)

In the manufacture of semi-molded clutch facings made of woven fabric and rubber material, flame retardant treatment of vegetable fibers such as cotton rayon is performed, followed by mixing with aromatic polyamide fibers, etc. to make a thick coarse yarn or a foot-woven fabric. It is characterized in that the interwoven yarn or foot-woven fabric is made, and the interwoven yarn or woven fabric is infiltrated and dried by the thermosetting resin liquid, and then the yarn or woven fabric to which the heat resistant rubber liquid is attached is wound on a clutch facing and molded by pressing and heating it. A method for manufacturing a non-asbestos clutch facing for a passenger car or an industrial vehicle. The method for producing a non-asbestos clutch facing according to claim 1, wherein a frictional performance enhancer is incorporated in the immersion-attached rubber liquid. The flame-retardant treatment according to claim 1 or 2, which is flame-retardant and twisted with aromatic polyamide fibers, infiltrated and dried in a thermosetting resin solution, and then wound a coarse thread to which a heat-resistant rubber solution is adhered to a coil spring and crushed in a plane. A method for producing a non-asbestos clutch facing, characterized in that it is made in the form of a clutch, and is formed by superimposing a single layer or a plurality of layers under pressure heating. The method for producing a non-asbestos clutch facing according to claim 1 or 2, wherein a metal wire is twisted together when said flame retardant treatment yarn and said fiber of aromatic polyamide are twisted together.

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