MXPA96002418A

MXPA96002418A - Friction material intended for use in a device that makes a dry friction, as well as the procedure for obtaining such friction material and the device in which it is provided

Info

Publication number: MXPA96002418A
Application number: MXPA/A/1996/002418A
Authority: MX
Inventors: Guerin Richard; Jacq Gerard
Original assignee: Valeo
Priority date: 1995-06-21
Filing date: 1996-06-20
Publication date: 1998-01-01

Abstract

The present invention relates to: A friction material for a dry friction device manufactured without the use of an organic solvent, said material being characterized in that it comprises a fiber mat impregnated with a thermosetting resin, the fibers an average length of 4 cm at 12cm, said mat additionally includes powder, wherein said mat is without an organic solvent.

Description

FRICTION MATERIAL INTENDED FOR USE IN A DEVICE WHICH MAKES A DRY FRICTION: AS WELL AS THE PROCEDURE FOR THE OBTAINING OF SUCH FRICTION MATERIAL AND THE DEVICE IN WHICH THIS IS PROVIDED The present invention aims at a friction material intended to be used < sree with a device that performs dry friction; as well as to the procedure for cib tHr.?-r said friction matt-Tial and the device e-n which is ready. M = =, particularly, said frictional m-ite is presented under the form of an annular piston, and the device in which it is provided is a clutch disc or a brake disc. ! • - > The dry friction materials that are used in The actuality of three main types: Matte materials based on yarns, materials based on woven yarns and yarns is molded. The materials based on yarns, or based on yarns - or tisu sides are constituted substantial almen e poc threads that have a reinforcing paper, impregnated with a tear-resistant resin, rubber and various loads. Matters] of such type present inconvenient div-ers. Its preparation makes it necessary to use -1-5 noxious solvents and must be provided for: • specific provisions in order to avoid any escaping solvt-nte into the natural environment. It has been proposed to replace the harmful solvents with water, but in this case it is also advisable to guarantee the purification of the water or the steam released at the end of the process of elaboration. They make onerous production procedures, they are also not fully integrated, and molded materials, which are generally obtained by wet process, following a mixing procedure, also require this same type. Additionally, the procedures used do not allow the use of anything other than relatively coarse reinforcing fibers (average length less than 5 mm), due to this, the molded friction materials present an insuffi The centrifugation, particularly hot, which makes them unsuitable for use in a dry clutch friction disc, is rotated at a rotational speed that can sec above 6,000. revolutions a minute The object of the present invention is to remedy the aforementioned drawbacks by proposing a dry friction material which has improved technical characteristics, a lower manufacturing cost of the known materials and whose processing not only involves the disposal of contaminants to the natural environment, J? O that allows recircuJar JOS raterjeíJJos de? We will use them, as well as the debris from the new friction surfaces. It also aims to propose a dry friction method that presents a coefficient of friction that is stable, as well as good resistance to wear. A dry friction material, according to the invention, is characterized in that it is constituted by an imitated fiber mat with a thermoenduible esible, and in that said fibers have a length of at least -mui. According to other characteristics taken separately or in combination: - the average length of the fibers, at most, is equal to 120 mm; - the fibers are selected from the group of fibers of air, viscrea, flax, polyacrylonitrile, pre-coiled polycycline, paca-aramid, meta-ara, of mineral fibers, for example, glass EC.-R, miperal wool, cer í? ii t; - glass is placed in the mat, in the form of silicon and / or fiberglass hiJcs and / or turquoise or valium; - the diameters of the glass fibers are between 6 and 21 micrometers; - the glass fibers have been selected for a process to make the inh r n s, an im m ation, a f ilic ion, a rubber im reg ation; - is it incorporated into the loading mat °? Dust that consists entirely of the following elements or compounds: copper, mineral wool, nitrile rubber powder, carbon black, hexa.i'fct íntentet raa i.na, gi sonson, litargo, resin Melamine, phenolic resin, sulfur, cardalite, zircanium silicate, iron oxide film, rubber, latex, used abrasives, reduced to dust, friction film re-dusting powders, zinc oxide. Fillers of short fibers can be incorporated into the mat, or be present in the J. The process for obtaining the dry friction material, according to the invention, is characterized by the following steps: a) a mixture of fibers of the same nature or of different components, such as a mixture, is obtained in a mixer. defined above, b) the mixture is carded to form a card veil, c) the card veil is formed to nap, d) it incorporates glass to the card veil at the time of day; it is pre-treated with needles or the ester 1 is condensed - between the steps b) and c) above, the pulverulent charges are sprinkled on the card web; : e carries out the label (.. or,!), or a type label for f > ** "" "has a mat up to a thickness of between 3 TG? / 10 r? *?, between different lenses; - The temperature is between 50 ° C and 50 ° C. C: - the pressure in between 1 baria and 10 bar m; g) is covered by the bands, in the seitido of your me hur < - the width of the bands is purchased between 100 mm and h) the bands thus chased are welded by means of sheets ca ef ctorae; - the temperature of the sheets is between 5 ° C and 12 ° C, - the coating of the welded strips is set at re 3 mai and 20 mm, (i) the welded strip is rolled in a rolled; j) said band is focma to a tube, whose inner diameter is obtained by means of a mandrel with an adjustable diapetro, and whose external diameter is obtained by means of a suitable anti-spinning yarn; it is comprised between 10 mm and 250 mm j - the outer diameter is compressed between LW mm and "+50 - the roller of said band is made in contact with the 3 heating elements; k) a ring of said tube thus obtained is cut; - the height of said ring is between 3 mm and 25 - the cutting of said ring is effected by means of blades d i viso e; 1) the ring is placed at the bottom of a mold; ) a pressure cooking is carried out in the mold; - the cooking temperature is co-limited between 150 ° C and 25 ° C * - the pressure applied to the material varies between 20 bar and 300 bar.Furthermore, the invention is aimed at a friction disc for rotating clutch, which effects a dry friction, comprising at least one friction lining and, preferably two, arranged on one side and another of a support, characterized in that said friction lining is formed from a defined friction material further back, obtained according to the procedure indicated above.Other characteristics and advantages of the product and the procedure will appear from reading the following description, from the examples of application and from the implementation of the invention, with respect to the attached drawings, which present: Figure 1, the outline of the principle of a first part of the installation intended to implement the product according to the invention; and Figure 2, the principle diagram of a second part of said installation. Three fiber mats (Examples A, B, C) are formed from the following fiber ions, indicated by weight: E.1JHPLQS FIBERS A B C PAN (poly i cr i ion and tri lo) or pre-oxidized PAN, parts 13 15 11 GLASS E 0? The average length of the fibers used is the same: PAN fibers: -2 muí; - glass fibers: "+0 mm The fibers or the mixture of fibers obtained above in a mixer, are introduced in the magazine 1 (figure 1) of a device of the imen tation 2 of a card 3 of the type for Jana, comprising a feed hopper 4. Powder loads are sprinkled at the outlet of the card 3, on the formed card web, by means of a sprinkling device 5.

The pulverulent charges μr *. * - nt < ? The unique composition and co-operation of the fish, with respect to the parts of the nested fibers - > ? pba > : CHARGES E1EMPLQS PULVERULENTAS A B C Residual dust from the lining rectification i *? friction 34.5 34.5 l ') Resin fen lica 33.3 14.0 33.3 Nitric rubber 7.5 9.0 7.5 Ca do 1 to 3.7 3. 7 zuf e 0.4 2.0 0.4 Carbon Black 4.7 H to Otratramine O.3 Lit rga 4.6 25 Resin de me la ina 1 .3 Zinc oxide 0.3 ? Powder of colare 4 .6 The vidna was injected into the card veil formed by an average of a fixation plate 7 »The glass has the following composition 'composition by weight, in relation to the parts by weight of the above-mentioned powdered arqas with antiority): E.IEMPL? S GLASSES A B c of the icon 7 3. 5 textu r i zado 3 The glass used is E glass, whose diameter or medium is: - continuous glass thread (silicone): 9 micrometers; - glass thread desribed: .12 ic ró et ros. Next, the card veil is covered by a napper 6; and the nap thus formed is subjected to a pre-treatment with needles in the roller 3. The non-woven mat, thus formed, is carried, in the example shown, to a determined thickness between the heating plates 9. The mat thus compressed in the example represented, is cut by a guillotine in the direction of its width 10. The bands cut in the example shown are welded by a heating foil, and is rolled to a roll 11, at the exit of the first part of the installation. The roll 1 1 is taken, in a second part of the installation, and is divided for the co-operation of the procedure for the removal of the friction material (Fig. A tube 14 is shown, in the example rep ces The internal diameter of the tube 14 is defined by means of a mandrel, of adjustable diameter by means of rings 15. The outer diameter of the hub 14 is defined by means of a mandrel, by means of contact with cylindrical tubes. The length of the rings is 15 mm, and each tube is cut in a mold which, according to the equipment, is placed in a mold. The friction material must be de-invested, it has a grooved or ungrooved bottom plate, and the mold is made under pressure, the mold is opened and the ring thus obtained is cooled. OJar.Turn ring in a tunnel, according to a cycle of treatment at different temperatures. The annealed ring is subjected to dimensioning operations in the thickness, drilling and rolling. The residues of the operations of thicknessing, drilling and rolling are recovered, so that they can be used again. Three series of two friction discs for clutch, obtained in accordance with the invention from the compositions of the above exemplary axes A, B, C, are subjected to resistance tests in the same conditions indicated above. 3e place two discs of the same series, which correspond to the same embodiment, in a machine that analyzes the ti or defined by the ECF 07005 standard. The analysis comprises four series of cycles. Each cycle consists of braking to stop a mass of inertia previously carried at a rotation speed of 3,000 revolutions per mi. ñuto. The first series comprises 500 cycles, the inert mass being 43 kD. The second series comprises 1,000 cycles, the inert mass being 43 k3. The t r series consists of 1,000 cycles, the inert mass being 62 kD. The fourth series comprises 500 cycles, the inert mass being 31 kD. The following table shows the evolution of the coefficient of dynamic friction of each of the three samples, during the cycles of resistance c iornados a riba.

It is found that the friction material according to the invention has a remarkable stability of the coefficient of friction of the material. It is further verified that the friction material according to the invention has only suffered a very b wear (AJO.

Claims

NOVELTY of the INVENTION CLAIMS .1. - Friction material intended to be used in a diaphragm that performs a dry friction »more particularly a clutch or brake disc, bristling face because it is constituted by an esteri of fibers i. impregnated with an ibl thermoset resin, and said fibers have a length of at least 40 mm.
2. Friction material according to claim 1, further characterized in that the length of the fibers is at most 120 mm. 3. Friction material according to claim 1 or 2, further characterized in that the fibers are selected from the group of cotton fibers, linen viscose, polyac. ri ry ion, of polyacid ion, the pre-oxidized, of para-aramid, of meta-aramid, of mineral fibers such as glass E-C-R, mineral wool, ceramics. 4. Friction material in accordance with claim 3, curly face further because glass is incorporated into the esteriJJa in the form of silicone and / or wick and / or textuizado or voluized. 5.- Friction material in accordance with claim 4, further characterized by the diameters of m The glass fibers are omitted between 3 and 21 minutes. 3. Friction material according to claim 5, further characterized in that the glass fibers are subjected to a bonding process, to an i. Prenatally with phenolic resin, or with a phenolic resin with a halo. 7. Friction material in accordance with any of claims 1 to 3, also characterized in that powder loads are incorporated in the mat.
3. Friction material according to claim 7, further characterized in that the powder charges consist totally or partially of the following elements or compounds: copper, mineral wool, nitrile rubber powder, carbon black, hexamethine lens, gilsonite , litargo, melamine resin, phenolic resin, sulfur, cardolite, zirconia silicate, iron sulfide, alumina, latex, used clutch liners, reduced to dust, friction linings rectification powders, zinc oxide. 9.- Procedure for obtaining a friction material for dry friction, characterized in that it comprises the following stages: a) a mixture of fibers of the same nature or of different natures is obtained in a mixer, such as the def go to claims 1 to 3; b) the card is carved to form a card veil; c) the card view is formed to nappa; d) glass is incorporated into the card web in the course of the nappa formation; e) it is previously treated with needles or the latter is condensed. 10. Procedure according to claim 9, further characterized in that among the steps b) and c) powdered loads are sprinkled on the card web, such as those defined in claim 3. 11.- Agreed procedure can the claim 9, character i. Also, because the carding is carried out by means of a card of the wool type. .12.- Procedures in accordance with the rei indication 10 or 11, further characterized in that the mat is brought to a thickness between 3 mm and 10 mm, between hot plates. 13. Procedure according to claim 12, further characterized in that the temperature is within the range of 50 ° C and 100 ° C, and the pressure is between 1 baria and 10 bar. 14.- Procedure according to the claim 12 or 13, further characterized in that the ribbon is cut in the widthwise direction. 15. Process according to the rei indication 14, bristling face also because the width of the bands is between 100 and 450 mm. 13.- Procedure according to the rei iication .14 or 15, also characterized because the bands thus cut are welded by heating sheets. 1. 7. - Process according to Claim 13, also characterized in that the temperature of the sheets is between 50 ° C and 100 ° C, and the coating of the bands welded is between 3 mm and 20 mm. 13. Method according to claim 13 or 1.7, further characterized in that the welded strip is wound on a winder; and said band is formed to a tube whose inner diameter is obtained by means of a mandrel of adjustable diameter, and whose outer diameter is obtained by an appropriate length of unraveling. 19. Procedure of agreement n the rediction 13, further characterized in that a ring is cut in the tube forpiated. 20. Procedure according to the rei indication 19, further characterized in that the ring is placed in the bottom of a mold and a low pressure cooking is carried out in the mold. 21. Process according to claim 20, further characterized in that the cooking temperature is between 150 ° C and 250 ° C, and because the pressure applied to the material varies between 20 bars and 300 bars. 22.- friction disc for rotating clutch, which performs a dry friction, comprising at least one friction lining, characterized in that said friction lining is obtained from a friction material according to any one of claims 1 to 3. 23.- Friction disk for rotating clutch, according to claim 22, characterized in that the friction material is obtained according to the method of any of claims 9 to 21.