JP2008265031A - Manufacturing method for transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a transmission belt, which enables a material for a pile of a pile-implanted layer to be easily changed even if the type of the belt is changed, and which enables the transmission belt to be molded in a short time. <P>SOLUTION: After the formation of the pile-implanted layer 26 on a base material 56, the pile-implanted layer 26 separated from the base material 56 is wound around a rubber sleeve 24 for the manufacture of the rubber sleeve 24 with the pile-implanted layer. The rubber sleeve 24 with the pile-implanted layer is arranged between an inner mold 41 which is fitted with a flexible jacket 42, and an outer mold 46 which has a mold portion 45 engraved in the inner peripheral surface; a pre-molding body 21 is manufactured in such a manner that the flexible jacket 42 is expanded so that the rubber sleeve 24 can adhere to the engraved mold portion 45 of the outer mold; another sleeve 25 is manufactured in such a manner that at least a core wire is wound around the surface of the flexible jacket 42 of the inner mold separated from the outer mold 46; the inner mold 41 is installed in the outer mold 46; and a belt sleeve is manufactured by expanding the flexible jacket 42 and vulcanizing another sleeve 25 integrally with the pre-molding 21. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a transmission belt, and more particularly, to a method for manufacturing a transmission belt in which the material of a pile of a flocked layer can be easily changed even if the belt type is changed.

  2. Description of the Related Art Conventionally, a power transmission belt is known which is formed by laminating an adhesive rubber layer in which a core wire is embedded along the longitudinal direction of the belt and a compressed rubber layer having rib portions extending in the longitudinal direction of the belt and oriented short fibers in the width direction. It has been. In this method of manufacturing a transmission belt, generally, a sleeve formed by laminating an adhesive rubber layer having a core wire embedded in the longitudinal direction of the belt and a flat compressed rubber layer adjacent to the adhesive rubber layer is attached to a vulcanizing can. Then, a flat sleeve without a rib portion was vulcanized and molded, and the compressed rubber layer was shaved off with a polishing wheel, and was cut into rounds according to the required number of rib portions. However, a considerable amount of material loss has occurred because the rib portion is formed by grinding the compressed rubber layer of the sleeve.

  As a method for improving this, Patent Document 1 describes a power transmission member in which napping is provided on the contact surface of at least one of the power transmission side and the transmitted surface by electrostatic flocking to reduce noise during traveling. ing.

  Further, in Patent Document 2, a belt molded body is formed by providing a flocked layer on an unvulcanized rubber sheet forming a rib portion and pressing the rib portion on an outer mold engraved with the rib portion.

Japanese Patent Laid-Open No. 9-14361 JP 2004-249704 A

  However, in the conventional transmission belt manufacturing method, adhesive is applied to the surface of the rubber sleeve molded on the inner mold surface, and electrostatically implanted short fibers (pile) are electrostatically flocked. When manufacturing the belt, the flocking device has become large due to the large mold. In addition, when the pile type is exchanged, it is necessary to exchange all the piles in the apparatus. Furthermore, it is difficult to accurately measure the amount of pile pile.

  The present invention pays attention to such a problem, and as a result of earnest research, it provides a method for manufacturing a transmission belt that can easily change the material of the pile of the flocked layer even if the belt type changes and can be molded in a short time. For the purpose.

In order to achieve the above-mentioned object, the invention according to claim 1 of the present invention includes a rubber layer in which a core wire is embedded along the longitudinal direction of the belt, and a rib portion extending in the longitudinal direction of the belt adjacent to the rubber layer or the longitudinal direction of the belt. In the manufacturing method of the transmission belt in which the mold part made of the cog part provided at a predetermined interval is laminated,
After forming the flocked layer on the base material, the flocked layer peeled off from the base material is attached to the rubber sleeve to produce a rubber sleeve with a flocked layer,
The rubber sleeve is disposed between an inner mold fitted with a flexible jacket and an outer mold in which a mold part made of a rib mold or a cog mold is engraved on the inner peripheral surface,
The flexible jacket is inflated and the flocked layer of the rubber sleeve is tightly molded to the mold part engraved on the outer mold, and the existing air is discharged from the flocked layer to produce a vulcanized belt molded body. It is in the manufacturing method of a belt. In this way, if a flocked layer previously peeled off from the substrate is used, even if the belt type changes and the flocked layer is changed by this, it can be prepared by using a separately prepared flocked sheet.

In the invention according to claim 2 of the present application, the belt molded body includes an outer mold in which a rubber sleeve with a flocking layer is attached, an inner mold in which a flexible jacket is mounted, and a mold portion made of a rib mold or a cog mold on the inner peripheral surface. Producing a preform so that the flexible jacket is inflated by placing it between the mold and the flocking layer of the rubber sleeve is in close contact with the stamped mold part of the outer mold,
A separate sleeve having at least a core wire wound around the flexible jacket surface of the inner mold is produced,
The inner mold is re-installed in the outer mold, the flexible jacket is expanded, and another sleeve is integrally vulcanized with the preform. In this method, after producing an unvulcanized preform, another sleeve around which the cord is wound is expanded and integrally molded, so that the extension of the cord can be suppressed. Can be molded.

  In the invention according to claim 3 of the present application, an adhesive layer and a flocked layer are sequentially formed on a substrate, and then a flocked layer with an adhesive layer peeled off from the release paper is attached to the rubber sleeve to produce a rubber sleeve with a flocked layer. .

  In the invention according to claim 4 of the present application, the substrate is made of a release paper, a mount, and a resin film.

  According to the above invention, after forming the flocked layer on the base material, if the flocked layer peeled off from the base material is wound around the rubber sleeve to produce a rubber sleeve with a flocked layer, the belt type is changed, thereby changing the flocked layer. Even if it exists, it can respond to preparation by using the flocking layer formed on the base material prepared separately, Furthermore, a transmission belt can be manufactured in a shorter time than the process of direct electrostatic flocking.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
In the present invention, a rubber sheet in which short fibers forming a compressed rubber layer are oriented in the width direction is produced. As a production method thereof, there are an extrusion method and a rolling method using a calendar. Of course, a rubber sheet containing no short fibers can also be used.

  In the following, as an example, when a rubber sheet in which fibers are oriented in the width direction is prepared by an extrusion method, 10 to 40 parts by mass of short fibers are previously added to 100 parts by mass of the polymer by an open roll and kneaded. Thereafter, the kneaded master batch is discharged once and cooled to 20 to 50 ° C. to prevent rubber scorching.

  When 1 to 10 parts by mass of a softening agent is added, the familiarity between the short fibers and the rubber is improved, and the dispersion into the rubber is improved. In addition, the short fibers themselves are prevented from being entangled and becoming cottony. In other words, the softener penetrates into the short fibers and acts as a lubricant for loosening the entanglement between the elementary fibers, prevents the short fibers from becoming cottony, and the familiarity between the short fibers and the rubber. Improves short fiber dispersion

  Subsequently, after the master batch is kneaded with an extrusion screw of a cylinder in an extruder, the temperature is usually adjusted to 40 to 100 ° C., the rubber mixed with short fibers is smoothly flowed to the rubber passage made of the environment expansion die, and the rubber While passing through the passage, it is extruded into a cylindrical molded body in which short fibers are oriented in the circumferential direction. Thereafter, the cylindrical molded body has a thickness of 1 to 10 mm in which short fibers are uniformly oriented in the circumferential direction from the inner layer to the outer layer, and is cut into one rubber sheet by a cutting means, followed by the rubber sheet. Cut the rubber sheet at predetermined intervals.

  The raw rubber for the rubber sheet used here is natural rubber, butyl rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, alkylated chlorosulfonated polyethylene, hydrogenated nitrile rubber, hydrogenated nitrile rubber and unsaturated carboxylic acid. A mixed polymer with an acid metal salt, a rubber material such as ethylene-α-olefin elastomer made of ethylene-propylene rubber (EPR) or ethylene-propylene-diene monomer (EPDM), or a mixture thereof is used. Examples of diene monomers include dicyclopentadiene, methylene norbornene, ethylidene norbornene, 1,4-hexadiene, cyclooctadiene, and the like.

  The rubber sheet is made of fibers such as aramid fiber, polyamide fiber, polyester fiber, and cotton, and the length of the fiber varies depending on the type of fiber, but a short fiber of about 1 to 10 mm is used, for example, an aramid fiber. About 3 to 5 mm, polyamide fibers, polyester fibers, and cotton are about 5 to 10 mm. The addition amount is 10 to 40 parts by mass with respect to 100 parts by mass of rubber.

  Furthermore, a softener, a reinforcing agent composed of carbon black, a filler, an anti-aging agent, a vulcanization accelerator, a vulcanizing agent, and the like are added to the rubber sheet.

  Examples of the softening agent include general rubber plasticizers, for example, phthalates such as dibutyl phthalate (DBP) and dioctyl phthalate (DOP), adipates such as dioctyl adipate (DOA), and dioctyl sebacate (DOS). Sebacates, phosphates such as tricresyl phosphate, etc., or general petroleum softeners are included.

  Subsequently, as shown in FIG. 1, the outer peripheral surface of the flexible jacket 42 made of vulcanized rubber attached to the inner mold 41 is made of release paper or a resin film such as polyterafluoroethylene, polyester, polyamide, or polycarbonate. After a release sheet (not shown) is wound, a rubber sheet 22 with short fibers oriented is wound, and wrapped or butt jointed to produce an unvulcanized rubber sleeve 24.

  Next, the adhesive layer 23 is provided by applying an adhesive to the surface of the rubber sleeve 24 by a known method such as a spray method or a dip method while rotating the inner mold 41 placed on the base 30. Examples of the adhesive include organic solvents such as toluene and methyl ethyl ketone, rubber adhesives, RFL (resoricin-formaldedo-latex) adhesives, urethane emulsions, acrylic emulsions, vinyl acetate emulsions, and styrene emulsions. The RFL liquid is obtained by mixing an initial condensate of resorcin and formaldehyde in a latex. Examples of the latex used here include chloroprene, styrene-butadiene-vinylpyridine terpolymer, hydrogenated nitrile, NBR, ethylene. This is an α-olefin-diene copolymer rubber latex. An isocyanate compound can also be added to the RFL solution.

  In addition, before apply | coating an adhesive agent, the surface treatment of the rubber material 22 can also perform pre-processing, such as cleaning processes, such as alcohol wiping, and a primer process. Although the thickness of the contact bonding layer 23 is not specifically limited, In order to make a short fiber favorable, it is about 10 micrometers-100 micrometers.

  Subsequently, as shown in FIG. 2, it is composed of a release paper, a mount, a resin film, etc., and preferably an adhesive is applied to the surface of the substrate 56 made of a release paper by a known method such as a spray method or a dip method. An adhesive layer 29 is provided. Then, using a known electrostatic flocking machine, a pile made by electrodeposition treatment of a surface made of rayon, cotton, polyester, nylon, aramid, vinylon, carbon fiber, polytetrafluoroethylene, etc. is supplied and allowed to fly. A flocking layer 26 is provided. In particular, it is not necessary to provide the adhesive layer 29 on the surface of the flocked layer 26.

  The thickness of the flocked layer 26 is 0.5 to 3 mm. When the thickness is less than 0.5 mm, the amount of short fibers decreases, and the effect of sound generation countermeasures is reduced by falling off the belt surface in a short time. However, if it exceeds 3 mm, the amount of short fibers increases, air permeability is impaired, and air after molding tends to be inherent.

The length of the pile is preferably 0.1 to 5.0 mm, and the aspect ratio (length Lmm / thickness diameter Dmm is 30 to 300. Further, the density of the flocked yarn contributes to the friction coefficient and sound during running. The speed of the belt is about 10,000 to 500,000 / cm ^2, which is a recent transmission belt used today.

  Then, after peeling the flocking layer 26 with the adhesive layer 29 from the base material 56 as shown in FIG. 3, the sheet-like flocking layer 26 is wound around and adhered to the surface of the rubber sleeve 24 as shown in FIG. .

  Next, as shown in FIG. 5, the inner mold 41 on which the rubber sleeve 24 with the flocked layer 26 is mounted is placed on the base with a certain gap inside the outer mold 46. Since the inner mold 41 is moved from another molding process, the medium distribution port A and the medium feeding / discharging path B are separated. After the inner mold 41 is placed on the base, the medium distribution port A is Connect to the pipe with joint J.

  The medium feeder is operated to feed high-pressure air or high-pressure steam into the flexible jacket 42 through the medium inlet / outlet passage B and the medium circulation port A. Since the upper and lower portions of the flexible jacket 42 are hermetically fixed on the inner mold 41, air is filled between the inner surface of the flexible jacket 42 and the outer surface of the inner mold 41. It gradually expands. Then, the flocked rubber sleeve 24 mounted on the outer peripheral surface is uniformly expanded in the radial direction, and contacted with the rib mold 45 of the outer mold 46 heated to 100 to 160 ° C. with a heater or high temperature steam for 30 to 120 seconds. Let me.

  At this time, the implanted rubber sleeve 24 is pressed against the rib mold 45 of the outer mold 46 by the expansion pressing force of the flexible jacket 42, and a plurality of V-shaped projections 27 are formed on the surface as shown in FIG. The unvulcanized preformed body 21 is formed. Then, the implanted short fibers are exposed to the surface without being embedded in the rubber by the rubber flow, and are firmly bonded to the flocked layer 23.

  Thereafter, the valve is switched to the vacuum pump, the air filled in the flexible jacket 42 is exhausted, and then the flexible jacket 42 is returned to its original position by suction.

  Then, the inner die 41 is removed from the outer die 46, and a reinforcing wire 47, an adhesive rubber 49, and a cord 48 made of a cord are sequentially wound around the outer peripheral surface of the flexible jacket 42 of the inner die 41 to provide another sleeve 25. Form. Thereafter, the inner die 41 is reinstalled in the outer die 46 as shown in FIG. 7, and then the flexible jacket 42 is inflated as shown in FIG. 8, and the other sleeve 25 is uniformly inflated in the radial direction. Then, the belt sleeve 51 is vulcanized in close contact with the preformed body 21 attached to the mold part 45 of the outer mold 46 which is heated to 100 to 180 ° C. with a heater or high-temperature steam. Make it. At this time, the air existing between the outer mold 46 and the flocked layer 26 is discharged through the flocked layer 26 as a passage, so that the surface of the rib portion is formed into a flat surface without any depressions or protrusions. The

  By molding the unvulcanized preform 21 as in the above manufacturing method, the extension amount of the other sleeve 25 due to the expansion of the flexible jacket 42 is suppressed during molding, and the core wire 48 is arranged flat. And a V-ribbed belt having excellent dimensional stability can be produced.

  After vulcanization, the flexible jacket 42 is contracted as shown in FIG. 9 and the inner die 41 is removed from the outer die 46, and then the vulcanized belt sleeve 51 attached to the outer die 46 is pulled out. On the surface of the die-attached portion 27 of the vulcanized belt sleeve 51, short fibers (planted yarn) are fixed to the surface layer 23 of the die-attached portion 27, raised at various angles, and exposed.

  Furthermore, while the vulcanized belt sleeve 51 is inserted into another one- or two-axis drum and rotated, it is cut into a predetermined width in the circumferential direction, taken out from the drum and reversed, so that the circumference is constant. A V-ribbed belt 1 in which V-shaped ribs were accurately formed was obtained. When the outer mold 46 is a split mold, the unvulcanized sleeve can be easily inserted and the vulcanized sleeve can be easily removed, and the split surface can function as a kind of air vent to further enhance the V-shaped rib. It can be formed accurately.

  The embodiment described above can be implemented with the following modifications.

  First, as described above, it is not necessary to stack and integrate the unvulcanized preform and another sleeve. That is, at least a core wire is wound around the inner flexible jacket surface, and an unvulcanized rubber sleeve having a short fiber implanted on the surface layer is laminated thereon to finish a belt molded body. It is placed between the outer mold with a rib or cog mold on the peripheral surface, and the flexible jacket is inflated so that the belt molding is in close contact with the stamped mold of the outer mold. Vulcanized belt sleeves can also be made.

  In addition, the base material to which the flocking layer is attached is superimposed on the rubber sheet surface, heated and pressurized, then the base material is peeled off, and the flocking layer is transferred to the rubber surface to produce a rubber sheet with a flocking layer. You may produce from a rubber sheet to a rubber sleeve. Furthermore, when a release paper is used as a base material, heating and pressurization is not necessary, and the flocked layer can be transferred to the rubber surface by peeling the base material.

  Further, as described above, it is not necessary to contain short fibers in the rubber sheet forming the compressed rubber layer.

  Alternatively, a surface layer obtained by baking a rubber sleeve with a heater may be formed while the inner mold is placed on a rotary table and rotated, and the flocked layer may be transferred onto the surface layer. The surface layer is heated at 350 to 500 ° C. for about 1 to 4 seconds to become a partially vulcanized skin layer. Even after vulcanization, the rubber flow is suppressed and the flocked yarn is not embedded in the rubber. . The thickness of the surface layer is about 0.1 to 1 mm.

  FIG. 10 is a cross-sectional view of the obtained V-ribbed belt. The V-ribbed belt 100 has a cord 102 made of a cord having high strength and low elongation embedded in an adhesive rubber layer 103, and has a compression rubber layer 104 as an elastic body layer below the cord. The compressed rubber layer 104 is provided with a plurality of rib portions 106 (molded portions) having a substantially triangular cross section extending in the longitudinal direction of the belt, and the short fibers 109 are arranged in a wave shape on the inner layer 110 of the rib portion so that the lateral pressure resistance of the belt is increased. Further, the flocked short fibers 108 are fixedly exposed on the surface layer 111 of the rib portion. The surface layer 111 includes an adhesive layer 107.

  The rubber used for the adhesive rubber layer 103 is similar to the rubber compound of the compressed rubber layer 104 excluding short fibers. Of course, short fibers may be included.

  As the core wire 102, a polyester fiber, an aramid fiber, and a glass fiber are used. Among them, the total number of deniers obtained by twisting together polyester fiber filaments having ethylene-2,6-naphthalate as a main constituent unit is 4,000 to 8, A cord subjected to adhesion treatment of 000 is preferable in order to keep the belt slip ratio low and extend the belt life. Further, the core wire 102 is subjected to an adhesion treatment for the purpose of improving the adhesion to rubber. As such an adhesion treatment, it is common to immerse the fiber in an RFL solution and then heat-dry to form a uniform adhesion layer on the surface. However, the present invention is not limited to this, and there is a method of performing a pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.

  The core wire 102 can be finished into a belt having a high modulus by setting the spinning pitch, that is, the winding pitch of the core wire to 0.9 to 1.3 mm. If it is less than 0.9 mm, the cord cannot ride on the adjacent cord and cannot be wound, while if it exceeds 1.3 mm, the modulus of the belt gradually decreases.

  The back reinforcing material 105 is selected from a woven fabric, a knitted fabric, a non-woven fiber material, or a rubber material, and a more preferable one is a non-woven fabric. Examples of the constituent fiber material include natural fibers such as cotton, hemp, and rayon, and organic fibers such as polyamide, polyester, polyethylene, polyurethane, polystyrene, polyfluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester, and aramid. Can be mentioned. The canvas is immersed in an RFL solution according to a known technique and then subjected to friction by rubbing unvulcanized rubber against the back reinforcing material 105, or is immersed in a soaking solution in which the rubber is dissolved in a solvent after being immersed in the RFL solution.

  In such a V-ribbed belt, the short fibers 108 are uniformly adhered to the surface of the rib portion and become a flat surface, reducing noise during belt running and further preventing cracks from occurring on the surface of the rib portion.

  The embodiment described above can be implemented with the following modifications.

  First, in the said embodiment, although the compression rubber layer demonstrated by the type containing the short fiber oriented in the width direction, the compression rubber layer which does not contain a short fiber for cost reduction may be sufficient. Even for compressed rubber layers that do not contain short fibers, sleeves are laminated and vulcanized while maintaining the alignment of the core wires while maintaining the flow of the compressed rubber layer along the ribs. Can do.

  Instead of short fibers, a solid lubricant can be blended in the compressed rubber layer. This solid lubricant is selected from hexagonal or scaly graphite, diverted molybdenum, and polytetrafluoroethylene, and the amount added is 10 to 100 parts by weight, preferably 100 parts by weight of raw rubber. Is less than 10 parts by mass, and when the amount is less than 10 parts by mass, if the amount exceeds 10 parts by mass, the elongation of the rubber properties is reduced and the belt life is shortened.

  The rubber sleeve 24 can be a compressed rubber layer alone, and the other sleeve 25 can be a laminate with an adhesive rubber layer. In this case, the flow along the rib is only the compressed rubber layer, and the entire adhesive rubber layer is isolated from this flow, so that the alignment state of the core wire 48 is further ensured. However, an appropriate material is selected so that the vulcanization joining of the compressed rubber layer and the adhesive rubber layer in a heated and pressurized state can be reliably performed.

  Moreover, it can also be set as the transmission belt of the type which does not laminate | stack a back surface reinforcing material. Specifically, as shown in FIG. 11, the V-ribbed belt 100 is not provided with an adhesive rubber layer, is composed of a rubber composition that does not contain short fibers as the compressed rubber layer 104, and is provided with a back flocking layer 115 on the surface. It may be.

  Moreover, a low edge cog belt can also be shape | molded with the manufacturing method of the power transmission belt using the type | mold apparatus mentioned above. This belt includes a core wire embedded in a spiral shape in the longitudinal direction of the belt in an adhesive rubber layer, a stretched rubber layer laminated on the upper side (belt outer peripheral side) of the core wire, and a lower side (belt) of the core wire It is composed of a compressed rubber layer laminated on the inner peripheral side, and the compressed rubber layer has cogs having alternating concave and convex portions provided at predetermined intervals. Reinforcing cloth is provided on the back surface of the stretch rubber layer and the cog portion surface of the compression rubber layer.

  When molding this belt, the outer mold 46 may be provided with a mold portion 45 corresponding to a cog mold extending in the longitudinal direction of the outer mold 46 at a predetermined interval along the inner peripheral direction of the main body. The structure of the other mold devices remains unchanged.

  The transmission belt manufacturing method and the transmission belt of the present invention can be applied to transmission belts such as a V-ribbed belt and a low-edge V-belt that reduce noise during belt travel and reduce belt elongation.

It is sectional drawing which shows the state which wound the rubber sleeve around the inner type | mold. It is sectional drawing of the state which made the flock layer adhere to the surface of a base material. It is a figure which shows the state of the flocked layer peeled from the surface of the base material. It is a figure which shows the state which wound the flocking layer around the surface layer of the rubber sleeve. It is a longitudinal cross-sectional view of the state which shape | molds a preforming body. It is sectional drawing of a state after producing a preforming body. It is sectional drawing of the state before producing a sleeve. It is sectional drawing of the state which has vulcanized the sleeve. It is sectional drawing of a state after vulcanizing a sleeve. It is sectional drawing of the V-ribbed belt obtained with the manufacturing method of this invention. It is sectional drawing of the other V-ribbed belt obtained with the manufacturing method of this invention.

Explanation of symbols

21 Pre-molded body 22 Rubber material 23 Surface layer 24 Rubber sleeve 25 Another sleeve 26 Flocking layer 27 Molding portion 41 Inner die 42 Flexible jacket 45 Mold portion 46 Outer die 51 Belt sleeve 56 Base material 100 V-ribbed belt 102 Core wire 102
103 Adhesive rubber layer 104 Compressed rubber layer 106 Rib part 107 Adhesive layer 108 Flocked short fiber 110 Inner layer 111 Surface layer

Claims (4)

Laminate a rubber layer with a core wire embedded in the belt longitudinal direction and a die-attached portion consisting of a rib portion extending in the longitudinal direction of the belt adjacent to the rubber layer or a cog portion provided at a predetermined interval in the belt longitudinal direction. In the manufacturing method for the transmission belt,
After forming the flocked layer on the base material, the flocked layer peeled off from the base material is attached to the rubber sleeve to produce a rubber sleeve with a flocked layer,
The rubber sleeve is disposed between an inner mold fitted with a flexible jacket and an outer mold in which a mold part made of a rib mold or a cog mold is engraved on the inner peripheral surface,
The flexible jacket is inflated and the flocked layer of the rubber sleeve is closely molded to the stamped mold part, and the existing air is discharged from the flocked layer to produce a vulcanized belt molded body.
A method of manufacturing a power transmission belt characterized by the above. The belt molded body is
A belt sleeve with a flocking layer is placed between an inner mold with a flexible jacket and an outer mold with a rib or cog mold on the inner peripheral surface to expand the flexible jacket. A preform is produced so that the flocked layer of the rubber sleeve is in close contact with the stamped mold part of the outer mold,
A separate sleeve having at least a core wire wound around the flexible jacket surface of the inner mold is produced,
The transmission belt according to claim 1, wherein the inner mold is re-installed in the outer mold, the flexible jacket is expanded, and another sleeve is integrally vulcanized with the preform. Production method.   The power transmission belt according to claim 1 or 2, wherein an adhesive layer and a flocked layer are sequentially formed on a substrate, and then the flocked layer with an adhesive layer peeled off from the release paper is attached to the rubber sleeve to produce a rubber sleeve with a flocked layer. Manufacturing method.   The method for manufacturing a transmission belt according to any one of claims 1 to 3, wherein the base material is selected from a release paper, a mount, and a resin film.

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