JP6668707B2 - Friction material for sliding parts and method of manufacturing the same - Google Patents

Description

  The present invention relates to a friction material for a sliding component used for a sliding surface of a sliding component such as a synchronizer ring, and a method for manufacturing the same.

  Conventionally, a carbon friction material used for a synchronizer ring is composed of a composite material obtained by solidifying carbon particles, carbon fiber, wollastonite, and copper alloy particles with a phenol resin.

  The carbon friction material in which the particles are solidified is superior in durability to friction materials made of copper alloy synchro, resin synchro, molybdenum sprayed synchro, and the like, and has been increasingly used recently.

JP 05-24747 A JP 2005-163011 A JP 2013-155330 A Japanese Patent No. 5516828

  However, the weak point of this carbon friction material is that when a high load such as a jump shift is applied and the film surface becomes 300 ° C. or more, the phenol resin is thermally degraded, and the film is broken down and abnormally worn. .

  In other words, wollastonite, which has poor heat conductivity, is used as a reinforcing material for the conventional carbon friction film, and short fibers are used for the carbon fiber. Is difficult to escape and heat is stored. For this reason, there is a problem that the temperature of the film becomes high, the phenol resin deteriorates, the composite material is broken, and abnormal wear occurs.

  Therefore, an object of the present invention is to solve the above-mentioned problems and to provide a friction material for a sliding component that can release heat even when the film surface becomes high temperature and hardly cause deterioration of a resin, and a method of manufacturing the same. is there.

  In order to achieve the above object, the present invention provides a friction material for a sliding component, wherein the friction material is made of a carbon cloth obtained by plain weaving a carbon fiber tow.

  The carbon cloth is made by plain weaving a tow in which 3000 to 6000 carbon fibers each having a single fiber thickness of 7 to 15 μm are bundled.

  The present invention also provides a friction material for a sliding part, wherein a plurality of plain-woven carbon cloths are laminated on the surface of the sliding part using a phenol resin, and heated and pressed to form a friction material. It is a manufacturing method.

  The carbon cloth is formed by plain weaving a tow in which 3000 to 6000 carbon fibers each having a single fiber thickness of 7 to 15 μm are bundled.

  It is preferable that high thermal conductive particles are coated on the surface of the plain-woven carbon cloth, and two or three carbon sheets coated with the high thermal conductive particles are laminated.

  The high thermal conductive particles are preferably made of 100-500 μm mille-foil spherical carbon.

  After applying an adhesive mixed with carbon nanotubes to the surface of the sliding component, the carbon cloth is overlaid, and the surface of the carbon cloth is coated with a phenol resin and the high thermal conductive particles are coated. After laminating a plurality of carbon cloths coated with high thermal conductive particles, it is preferable that the adhesive and the phenol resin are semi-cured, and then heated and pressed by a molding jig to form a friction material.

  ADVANTAGE OF THE INVENTION This invention demonstrates the outstanding effect that it can be set as a friction material which has good thermal conductivity and does not deteriorate resin by using a plain weave carbon cloth as a friction material.

FIG. 3 is a schematic view showing details of a carbon cloth used for the friction material of the present invention. It is a figure showing one embodiment of a manufacturing method of a friction material of the present invention. It is a partial sectional view of a synchronizer ring to which the friction material of the present invention is applied.

  Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  First, referring to FIG. 3, a synchronizer ring 10 as a sliding component to which the friction material of the present invention is applied will be described.

  A spline 12 that meshes with a gear cone (not shown) is formed on an outer peripheral surface of the ring main body 11, and a friction material 14 is adhered to a tapered surface 13 on an inner peripheral surface of the ring main body 11 to form the synchronizer ring 10. .

  Now, the friction material 14 of the present invention is constituted by a plain-woven carbon cloth 15 as shown in FIG.

  The carbon cloth 15 is formed by plain weaving a tow 16 in which 3000 to 6000 carbon fibers each having a carbon fiber thickness of φ7 to 15 μm are bundled.

  The friction material 14 is formed on the surface of the carbon cloth 15 by using a carbon cloth 15 in which mill-foil spherical carbon particles 17 are dispersed as high heat conductive particles.

  FIG. 2 shows a method of manufacturing the friction material 14 bonded to the tapered surface 13 of the ring main body 11.

  Spherical carbon particles 17 having an internal structure such as a mille-feuille shape are dispersed on the surface of a plain-woven carbon cloth 15, and a thin liquid phenol resin is applied and heated to 80 ° C. to be semi-cured. The carbon cloths 15a, 15b, and 15c in which the spherical carbon particles 17 are dispersed are laminated, and heated and pressed to produce the friction material 14 having a predetermined thickness.

  Since the carbon fibers of the carbon cloth 15 are continuous in the circumferential direction and in the width direction, the deterioration of the film can be prevented by quickly releasing frictional heat of the synchro surface generated under a high load such as a jump shift.

  The carbon cloth 15 having a thickness of about 0.2 mm can be obtained by weaving a tow 16 in which 3000 to 6000 carbon fibers having a fiber thickness of 7 to 15 μm are bundled. The weaving method of the carbon cloth 15 is a twill weave, which is flexible, but the crossed tows are easily displaced, and by using a plain-woven carbon cloth 15 weaving the vertical and horizontal tows alternately one by one, The film strength can be improved.

  The reason for applying the spherical carbon particles 17 is that the carbon cloth 15 transmits heat well in the fiber direction, but is difficult to transmit because of the presence of a resin in the thickness direction of the laminated film. Therefore, heat is transmitted also in the thickness direction by applying the spherical carbon particles 17 so that the carbon cloth 15 and the carbon cloth 15 are connected by the spherical carbon particles 17, and the heat is transferred to the iron base of the ring body 11 of the synchronizer ring. You will run away to the lumber.

  The reason for using the woven carbon cloth 15 is that, since the surface is wavy due to weaving the tow 16, the unevenness of the surface is large, and there is an effect of being excellent in running out of oil (oil drainage) at the time of synchronization. There is an effect that the mille-feuille-shaped spherical carbon particles 17 are fitted into the concave portions formed at the intersections of the vertical and horizontal tows so that they are less likely to shift.

  The particle size of the mille-feuille-shaped spherical carbon particles 17 dispersed in the carbon cloth 15 is such that the thickness of the carbon cloth 15 is about 0.2 mm, and if it is 100 μm to 500 μm, it is preferable that the diameter fits into the concave portion at the intersection. .

The dispersion amount of the spherical carbon particles is set to 10 to 150 particles in a square area of 1 cm ² .

  In FIG. 2, three carbon cloths 15 are laminated, but two or four or more carbon cloths may be laminated.

  Next, a specific example of manufacturing the friction material 14 by laminating the carbon cloth 15 coated with the mill-feuille-shaped spherical carbon particles 17 will be described.

(A) Pretreatment of carbon cloth (1) As pretreatment of carbon cloth, acetone is spray-sprayed on the surface of the carbon cloth. As a result, the acetone penetrates into the details, and the oil and resin components in the carbon cloth are removed.

  (2) Spray a 10-25% phenol resin dilution on the carbon cloth pretreated in (1). After evenly spraying the whole, the surface is extended with a brush or the like.

  (3) The carbon cloth of (2) is placed on a wire mesh formed in an arch shape according to the diameter of the tapered surface of the synchro ring, and heat treated at 140 to 150 ° C. for 30 minutes.

  (4) Cut with scissors or the like into a predetermined shape according to the tapered surface of the synchro ring.

(B) A blasting process is performed in advance on the joining surface that is the tapered surface of the resin ring main body of the joining surface of the synchronizer ring. A 30-75% diluted phenol resin to which 1-6% of VGCF (registered trademark) is added as a carbon nanotube is brush-coated on this joint surface. The addition of 1 to 6% of VGCF is for preventing aggregation of the phenol resin component.

  In addition, it is sufficient to apply a brush but only to cover the joints. If the thickness is too large, the resin component flows into the carbon cloth, which is not preferable. After applying this adhesive, heat treatment is performed at 100 to 120 ° C. for 30 minutes.

(C) Application of carbon cloth bonding resin The carbon cloth pieces cut in the pretreatment of (A) are formed on the tapered surface of the ring main body 11 as a lower carbon cloth 15a, an intermediate carbon cloth 15b, and an upper carbon cloth 14c. I do.

  At this time, a 30-75% diluted VGCF-containing phenol resin is applied to the tapered surface, and a 10-50% phenol resin is applied to the surface of each of the carbon cloths 15a, 15b, and 15c with a brush. Millfeuille-shaped spherical carbon particles are applied to the resin surface. Thereafter, the carbon cloths 15a, 15b, and 15c each coated with a 10% to 50% phenol resin and coated with the mille-feuille-shaped spherical carbon particles 17 are laminated on the tapered surface to which the adhesive has been applied. Heat treatment at 120 ° C for 30 minutes.

  The spherical carbon particles 17 applied to the lower carbon cloth 15a and the intermediate carbon cloth 15b are for the purpose of improving the thermal conductivity in the thickness direction of the film, and the spherical carbon particles 17 applied to the upper carbon cloth 15c in contact with the gear cone are This is for adjusting the coefficient of friction.

  By the heat treatment at 110 ° C. for 30 minutes, the carbon cloths 15a, 15b, and 15c are temporarily joined to the tapered surface of the ring main body.

(D) Molding of friction material In (C), the ring main body 11 to which the carbon cloths 15a, 15b and 15c are temporarily joined is transferred to a molding jig and set on a heating press. At this time, the upper and lower top plates of the heating press are set at about 190 ° C., and are kept in a state where no pressure is applied.

Next, when the temperature of the ring main body reaches 110 ° C. (jig temperature is 140 ° C.), pressure is applied by the upper and lower top plates so that the pressure receiving portion becomes 50 to 150 kg / cm ² .

  After 30 minutes have passed since the ring body temperature exceeded 170 ° C., the pressure was released and the jig was removed.

  Thereafter, after removing the burrs, after-curing is performed at 190 ° C. for 2 hours to complete the friction material.

  As described above, in the present invention, since a structure in which fibers are connected is formed by forming a film in which carbon cloth is laminated, a friction material having high film strength and excellent wear resistance can be obtained. Further, since the carbon fibers are connected in the circumferential direction and the ring thickness direction, heat is quickly released and the resin is hardly deteriorated.

  Further, by applying carbon particles between carbon cloths, heat is released in the film thickness direction, so that heat storage of the film can be suppressed.

  The carbon cloth is a cloth-like cloth obtained by plain weaving a tow obtained by bundling carbon fibers, and can improve the film strength.

  There are PAN-based and pitch-based carbon fibers. Particularly, the use of the pitch-based material improves the thermal conductivity of the friction material. In addition, a PAN-based material mainly having abrasion resistance is good.

11 Ring body 14 Friction material 15 Carbon cloth 16 Toe

Claims (1)

A method for manufacturing a friction material for a sliding component, comprising: laminating a plurality of plain-woven carbon cloths on the surface of the sliding component using a phenolic resin, and heating and pressing this to form a friction material.
After applying an adhesive mixed with carbon nanotubes to the surface of the sliding component, the carbon cloth is overlaid, a phenol resin is applied to the surface of the carbon cloth, and high heat conductive particles are applied. After laminating a plurality of carbon cloths coated with conductive particles, the adhesive and the phenol resin are semi-cured, and then heated and pressed by a molding jig to form a friction material. Manufacturing method of friction material for parts.

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