JP2004284198A - Transmission belt manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt manufacturing method capable of manufacturing a cogged belt low in cost by simplifying the joining work of the cog ridge parts of a sheet for a compressed rubber and reducing the occurrence of the defective percent of the joining work. <P>SOLUTION: A reinforcing fabric 6 is placed on the surface of a mold 1 having ridge parts 4 and groove parts 5 alternately provided thereto and rod-shaped members 7 are fitted in the groove parts 5 to press the reinforcing fabric 6 and mechanically fixed to the bottom surfaces 8 of the groove parts to shape the reinforcing fabric 6. The sheet 10 for the compressed rubber is wound around the mold 1 to butt and join the cut surfaces 11 of the sheet 10 and, after a stickiness preventing material 15 is wound around the sheet 10 for the compressed rubber, the sheet 10 for the compressed rubber from which the respective rod-shaped members 7 are drawn out is heated under pressure to be shaped on the mold 1 and at least a core wire and a stretched rubber sheet are successively wound around the surface of the unvulcanized sheet 10 for the compressed rubber from which the stickiness preventing material 15 is removed to form a belt molded body 35. Thereafter, the belt molded body 35 is vulcanized and the obtained vulcanized sleeve is cut into a V-shape to produce the transmission belt. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a transmission belt, which is a cogged belt used as a transmission belt for snowmobiles, scooters, and general industry, and more particularly, to simplify a joining operation at a cog peak portion of a compressed rubber sheet, and to reduce a joining operation. The present invention relates to a method for manufacturing a power transmission belt capable of manufacturing a low-cost cogged belt with a reduced occurrence of a defective rate.
[0002]
[Prior art]
BACKGROUND ART Conventionally, in a scooter or a drive system of a general industrial machine field, a belt-type transmission that suspends a transmission belt between a drive pulley and a driven pulley, and changes the effective diameter of the pulley to change the speed has been used. The transmission belt used here has a cog portion in which a cog peak portion and a cog valley portion are alternately arranged on at least one of the compression rubber layer and the extension rubber layer, and the core wire is placed in the adhesive rubber layer. A low-edge cog belt such as a low-edge single cog belt or a low-edge double cog belt has been known.
[0003]
As the method (1) of the method for producing a low-edge cogged belt, an outer reinforcing cloth, a rubber sheet of an extension rubber layer, a cord, a rubber sheet of a compression rubber layer, and an inner reinforcing cloth are sequentially wound on a molding die. A method of molding a rubber sheet of a compressed rubber layer by inserting a cylindrical matrix having alternating protrusions and grooves, and then vulcanizing, by shrinking the inner reinforcing cloth by pressure during vulcanization. There is. (For example, disclosed in Patent Document 1.)
[0004]
Also, as (2), an unvulcanized rubber sheet is placed on a flat grooved mold longer than the belt circumference prepared in advance and heated and pressed by a press to produce a cog pad molded into a cog shape. I do. This cog pad is fitted into the protrusion and groove of the cylindrical mother die mounted on the forming drum, and the cut surfaces of the cog pad are butt-joined, then the core wire is wound, and another rubber layer and a reinforcing cloth are added to the cog pad. The molding was completed by winding from the top and moving to the vulcanization process. (For example, disclosed in Patent Document 2.)
[0005]
Further, as (3), a canvas placed on a flat grooved mold is molded with a pinion roll, and then a rubber sheet is placed and pressed by a press to produce a cog pad molded into a cog shape. I do. This cog pad is fitted into the protrusion and groove of the cylindrical mother die mounted on the forming drum, and the cut surfaces of the cog pad are butt-joined, then the core wire is wound, and another rubber layer and a reinforcing cloth are added to the cog pad. The molding was completed by winding from the top and moving to the vulcanization process. (For example, disclosed in Patent Document 3)
[0006]
[Patent Document 1]
U.S. Pat. No. 3,646,875 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2002-1691 [Patent Document 3]
JP-A-2002-188691
[Problems to be solved by the invention]
However, transmission belts for transmissions such as conventional scooters have been mainly composed of chloroprene rubber, but recently transmission belts having more heat resistance, lateral pressure resistance, and wear resistance have been required. . Therefore, in the method (1), when a belt having a small shrinkage is used as the core of the belt, the core does not shrink when the rubber sheet of the compression rubber layer and the inner canvas are press-fitted during vulcanization. There was a meandering defect.
[0008]
In the method of (2) for preparing a cog pad in advance, an unvulcanized rubber sheet cut into a predetermined length in advance is placed on a flat press and heated and pressed. It is necessary to cut to the required length, and the flat press requires die replacement, which results in a time loss in setup change and the like.
[0009]
In addition, the cutting of the molded cog pad is performed manually by a skilled worker, and the worker counts the number of cogs in advance according to the belt circumference and marks the cog valley to be cut with chalk. One cog peak (the top of the cog) was cut by a cutter, and the other cog peak was similarly cut.
[0010]
However, when the molded body obtained by this method is vulcanized, the outer canvas of the reinforcing cloth is stretched at the cog portion of the transmission belt due to the rubber flow due to the insufficient volume of the rubber located at the joint portion, and the inner fabric is stretched. The edges of the canvas were attracted, resulting in the inner canvas wrinkling in the cog valley. When this belt was run, the cog valleys became repetitive bending points, and cracks sometimes occurred early from the wrinkles. These grew and became cracks in the full-fledged cog valley, damaging the belt. Further, when the cog shape of the joint portion is not uniform and the volume is particularly large, stress is concentrated during running bending, and the joint portion may be damaged at an early stage.
[0011]
However, when the molded body obtained by this method is vulcanized, the outer canvas of the reinforcing cloth is stretched at the cog portion of the belt for belt transmission due to the flow of rubber due to insufficient volume of the rubber located at the joint portion. The edges of the inner canvas were attracted, resulting in the inner canvas wrinkling in the cog valley. When this belt was run, the cog valleys became repetitive bending points, and cracks sometimes occurred early from the wrinkles. These grew and became cracks in the full-fledged cog valley, damaging the belt.
[0012]
Further, in the methods (2) and (3), chloroprene and the like are easy to mold because of their high adhesiveness to the mold, but alkylated chlorosulfanated polyethylene, hydrogenated nitrile rubber, and hydrogen Rubber with excellent heat resistance, such as a mixed polymer of a nitrile rubber and an unsaturated metal salt of a carboxylic acid, has poor adhesiveness. Therefore, when molded using this rubber sheet and a reinforcing cloth treated with this rubber, the rubber is reinforced. The cloth and the rubber sheet peeled off and could not be molded. In particular, when a canvas is molded with a pinion roll, the reinforcing cloth sometimes floats in the air without following the mold. When the transmission belt thus molded was subjected to high load transmission, cracks were easily generated from the cog valleys of the compressed rubber.
[0013]
Therefore, the present invention can solve the above-mentioned problems, simplify the joining work at the cog ridges of the compressed rubber sheet, and reduce the occurrence of the defective rate of the joining work to produce a low-cost cogged belt. An object of the present invention is to provide a method for manufacturing a transmission belt.
[0014]
[Means for Solving the Problems]
According to the first aspect of the present invention, at least the compression rubber layer of the compression rubber layer and the extension rubber layer has a cog portion in which cog peaks and cog valleys are alternately arranged, and the core wire is embedded in the adhesive rubber layer. In the manufacturing method of the transmission belt formed as described above,
The reinforcing cloth is placed on the surface of the molding die having the protruding portions and the groove portions alternately, the rod-shaped member is fitted into the groove-shaped portion and pressed, and the bar-shaped member is mechanically fixed to the bottom of the groove-shaped portion. By doing, after molding the reinforcing cloth,
A sheet for compressed rubber that forms a compressed rubber layer is wound around a molding die, the cut surfaces are butt-joined,
After winding the anti-adhesive material around the surface of the compressed rubber sheet, the compressed rubber sheet from which the rod-shaped member has been removed is heated and pressurized and molded into the protrusions and grooves of the molding die,
An unvulcanized compressed rubber sheet from which the anti-adhesive material has been removed is wrapped with an expanded rubber sheet that forms at least a core wire and an expanded rubber layer on the surface of the unvulcanized compressed rubber sheet to form a belt molded body, and then vulcanized. A method for manufacturing a power transmission belt, comprising cutting a sulfurized sleeve into a V shape to produce a power transmission belt.
[0015]
According to the present invention, the reinforcing cloth is placed on the surface of the molding die having the projecting portions and the groove portions alternately, the rod-like member is fitted into the groove-like portion and pressed, and the rod-like member is successively placed on the bottom of the groove-like portion. Mechanically, the reinforcing cloth can be easily and reliably mechanically molded. Further, the compressed rubber sheet is obtained by wrapping the compressed rubber sheet on the surface of the reinforcing cloth and joining the cut surfaces in abutting manner, winding the anti-adhesive material on the surface of the compressed rubber sheet, and removing all the rod-shaped members. By heating and pressurizing the mold and making contact with the protruding part and groove part of the molding die, the skilled worker eliminates the joint work of the rubber and the reinforcing cloth at the cog peak part, and the joint part is located The quality of the product can be stabilized by eliminating cracks and wrinkles of the reinforcing cloth, which are defects caused by insufficient volume of rubber, and can stabilize product quality. Furthermore, it is not necessary to prepare cog pads in advance, so work in process can be reduced. And the production can be inlined.
[0016]
In the invention according to claim 2 of the present application, the means for mechanically fixing each bar-shaped member to the groove-shaped portion bottom surface is a method of pressing each bar-shaped member to the reinforcing cloth against the groove-shaped portion bottom surface by a holding band. In the manufacturing method, the reinforcing cloth can be molded by a simple mechanical method.
[0017]
According to the third aspect of the present invention, there is provided a method of manufacturing a power transmission belt in which a holding band is an elastic member which is elastically fastened to a molding die.
[0018]
The invention according to claim 4 of the present application is a method for manufacturing a transmission belt in which a reinforcing cloth is wound around a molding die and then a joint portion is overlapped.
[0019]
The invention according to claim 5 of the present application is a method for manufacturing a transmission belt in which the reinforcing cloth is a tubular canvas that is highly elastic in the circumferential direction.
[0020]
According to the invention as set forth in claim 6 of the present application, there is provided a method for manufacturing a power transmission belt in which the ends of the compressed rubber sheet are butted on a bias cut surface, and the joint is heated and pressurized to be joined. can do.
[0021]
The invention according to claim 7 of the present application resides in a method for producing a power transmission belt in which the anti-adhesive is at least one resin film selected from polymethylpentene and polyethylene terephthalate, and a film having excellent heat resistance and excellent release properties. Can be used.
[0022]
In the invention according to claim 8 of the present application, an anti-adhesive material is wrapped around the surface of the compressed rubber sheet, the molding die covered with the jacket is placed in a vulcanized can, and the compressed rubber sheet is heated and pressed to form a molding die. The present invention is directed to a method of manufacturing a power transmission belt in which a protrusion and a groove are pressurized and molded, and an unvulcanized compressed rubber sheet can be molded by applying heat and pressure in an ordinary vulcanizer.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 shows a step of molding a reinforcing cloth on a molding die in the production method of the present invention, FIG. 2 shows a state in which the reinforcing cloth is molded on the surface of the molding die in the production method of the present invention, and FIG. FIG. 4 shows a process in which a rubber sheet is wound around a molding die and the cut surfaces are butt-joined. FIG. 4 shows a process in which an anti-adhesive material is wound around the surface of the compressed rubber sheet after each rod-shaped member is extracted. 5 shows a process in which the compressed rubber sheet is heated and pressurized so as to be in close contact with the protruding portions and the groove portions of the molding die, and FIG. 6 shows a state in which the compressed rubber sheet is molded.
[0024]
First, as shown in FIG. 1, a molding die 1 is prepared in which a cylindrical mother die 2 having alternately projecting portions 4 and groove portions 5 is mounted on a base die 3 having a perfect circular cross section. The untreated reinforcing cloth 6 is pulled out and placed on the surface of the rotatable molding die 1, and the molding die 1 is rotated so that a metal or resin rod-like member 7 such as iron or stainless steel is formed into a groove-shaped portion. After being fitted into and pressed into the groove 5, the bar-shaped member 7 is further mechanically fixed to the groove-shaped portion bottom surface 8 to mold the reinforcing cloth 6.
[0025]
That is, when each of the rod-shaped members 7 is mechanically fixed to the groove-shaped portion bottom surface 8, the rubber and the coil spring mounted on both ends of the base die 3 immediately after the rod-shaped members 7 are fitted into the groove-shaped portions 5 and pressed. The reinforcing cloth 6 is elastically pressed against the groove-shaped portion bottom surface 8 by being locked to a pair of holding bands 9 made of an elastic member such as the like. The rod-shaped member 7 is fitted and pressed to be similarly locked to the holding band 9. After the reinforcing cloth 6 is wound in one ply in this manner, the reinforcing cloth 6 is cut by a cutter to complete the molding. This molding step is performed in an environment in which the molding die 1 is heated to room temperature or about 80 ° C.
[0026]
When the reinforcing cloth 6 is laminated in several plies, the reinforcing cloth 6 is wound around the surface of the molding die 1 by several plies, and then the bar-shaped member 7 is fitted into the groove-shaped portion 5 and pressed. The reinforcing cloth 6 can be molded by mechanically fixing the reinforcing cloth 6 to the bottom surface 8.
[0027]
The reinforcing cloth 6 is made of cotton, polyester fiber, nylon, or the like, and is a cloth woven in a plain weave, a twill weave, a satin weave, or the like, and may be a wide-angle canvas in which the warp and the weft have a crossing angle of about 90 to 120 °. After the reinforcing cloth 6 is subjected to the RFL treatment, the rubber composition is subjected to fiction coating to obtain a canvas with rubber. The RFL solution is obtained by mixing a latex with an initial condensate of resorcinol and formaldehyde, and the latex used herein includes chloroprene, styrene-butadiene-vinylpyridine terpolymer, hydrogenated nitrile, NBR and the like.
[0028]
As the other reinforcing cloth 6, a tubular canvas with a sewing machine joint can be used. In this case, the weft in the longitudinal direction of the belt is an aramid fiber, a polyamide fiber such as 6 nylon, 6.6 nylon, 12 nylon, a polyester fiber, a polyvinyl alcohol fiber, and the like. It is a multifilament yarn, a spun yarn made of meta-aramid fiber, and a twisted yarn of three types of urethane elastic yarn. In addition, other weft constructions include a multi-filament yarn of para-aramid fiber, an aliphatic fiber yarn (6 nylon, 6.6 nylon, polyester, polyvinyl alcohol, etc.), and a twist yarn of three types of urethane elastic yarn. It may be something. The warp is made of a filament yarn such as aramid fiber, polyamide such as 6 nylon, 6.6 nylon, and 12 nylon. Preferably, when a multifilament yarn in which the filament yarn of the aramid fiber is formed by converging the filament yarn of the para-based aramid fiber to the weft 2 is used, the rigidity is balanced and the canvas has a uniform thickness.
[0029]
Subsequently, as shown in FIG. 3, both end faces of the unvulcanized compressed rubber sheet 10 having a predetermined thickness, on which a compressed rubber layer is formed in advance, are cut in a bias shape. After the compressed rubber sheet 10 is wound around the molding die 1 on which the reinforcing cloth 6 is formed, and the cut surface 11 is abutted, the surface of the sheet 10 where the cut surface 11 is located is lightly lightened with a pressing jig (not shown). After pressing and joining, the joint is further formed by heating and pressing with a heating press 12 to form a joint portion 13. The heating and pressing conditions are a temperature of 80 to 120 ° C., a surface pressure of 1 to ² kg / cm ² , and a time of 10 to 30 seconds.
[0030]
The rubber of the compressed rubber sheet 10 used here includes natural rubber, butyl rubber, styrene-butadiene rubber, chloroprene rubber, ethylene / α-olefin rubber, alkylated chlorosulfanized polyethylene (ACSM), and hydrogenated nitrile rubber (H -NBR), a rubber material such as a mixed polymer of a hydrogenated nitrile rubber and an unsaturated metal carboxylate, or a mixture thereof.
[0031]
The compressed rubber sheet 10 is made of aramid fiber, polyamide fiber, polyester fiber, cotton, or other fiber in rubber, and the length of the fiber varies depending on the type of fiber, but short fibers of about 1 to 10 mm are used. Aramid fibers of about 3 to 5 mm and polyamide fibers, polyester fibers and cotton of about 5 to 10 mm are used. When the direction of the short fibers in the rubber layer is 90 ° that is perpendicular to the longitudinal direction of the belt, most of the short fibers are oriented in the range of 70 ° to 110 °. It is desirable.
[0032]
After a single ply of a resin film made of polymethylpentene or polyethylene terephthalate, which is an anti-adhesive material, and having excellent heat resistance and releasability is wound around the surface of the compressed rubber sheet 10 and joined together, and then joined together. Move to the molding process.
[0033]
A vulcanizing can can be used for the molding step. In this case, after covering the outside of the anti-adhesion material 15 with a rubber jacket 17 which is a vapor blocking material, this is set in a vulcanizing can, and the temperature is 160 to 180 ° C., and the external pressure is only 0.8 to 0.9 Mpa. Molding is performed for about 5 to 10 minutes to form an unvulcanized compressed rubber layer 20. Even if it is molded with a vulcanizing can, cracking of the joint portion 13 of the compressed rubber layer 20 does not occur. Needless to say, the molding can be performed by heating and pressing while pressing the outside of the compressed rubber sheet 10 with a pressing band instead of the vulcanizing can.
[0034]
FIG. 7 shows a state in which a belt molded body has been produced on the surface of the molded compressed rubber sheet. The molding die 1 is mounted on a molding machine (not shown), and polyester fiber, aramid fiber, glass fiber, etc. Is wound spirally, and an adhesive rubber sheet 31, which forms an adhesive rubber layer, an expanded rubber sheet 33, which forms an expanded rubber layer, and a reinforcing cloth 34, are sequentially wound to form a belt molded body 35. I do. Then, the molding die 1 taken out of the molding machine is set on a support table and a jacket (not shown) is fitted.
[0035]
The belt molded body 35 is transferred to a vulcanizer and vulcanized by a usual method. After vulcanization, the jacket, and then the cylindrical belt sleeve are extracted from the cylindrical mother die 2 of the molding die 1, and the belt sleeve is cut into a predetermined width to form a transmission belt 40 which is a cogged belt as shown in FIG. Is prepared.
[0036]
The stretched rubber sheet 33 uses the same rubber composition as the compressed rubber sheet 10, and the adhesive rubber sheet 31 is the same as the compressed rubber sheet 10, and may include the above-mentioned short fibers, but preferably does not include it.
[0037]
The transmission belt 40 has a core 42 made of a cord of polyester fiber, aramid fiber, glass fiber, or the like embedded in an adhesive rubber layer 41, and an extension rubber including a reinforcing cloth 43 on the upper and lower parts of the adhesive rubber layer 41, respectively. It has a layer 44 as well as a compressed rubber layer 45 containing a reinforcing cloth 43. The compression rubber layer 45 is provided with cog portions 48 in which cog valley portions 46 and cog ridge portions 47 are alternately arranged at a constant pitch along the belt longitudinal direction. Of course, a cog portion can also be provided on the surface of the stretched rubber layer 44.
[0038]
【Example】
Hereinafter, the effects of the present invention will be confirmed by more specific examples.
[0039]
As a reinforcing cloth, a wide angle plain woven canvas using a 50:50 weight ratio of twisted yarn of aramid fiber (trade name: Twaron) and polyethylene terephthalate fiber was prepared, and the canvas was immersed in an RFL solution, and then immersed in 150 ° C. C. for 2 minutes, and then the chloroprene rubber composition was subjected to friction coating to obtain a canvas with rubber.
A rubber composition composed of chloroprene rubber containing aramid short fibers was prepared for the compressed rubber sheet and the extended rubber sheet, and a rubber composition composed of chloroprene rubber containing short fibers also for the adhesive rubber layer. The thickness of the compressed rubber sheet is 6.6 mm, and the thickness of the stretched rubber sheet is 3.2 mm.
[0040]
A rubber composition composed of chloroprene rubber containing aramid short fibers was prepared for the compressed rubber sheet and the extended rubber sheet, and a rubber composition composed of chloroprene rubber containing short fibers also for the adhesive rubber layer. The thickness of the compressed rubber sheet is 6.6 mm, and the thickness of the stretched rubber sheet is 3.2 mm.
[0041]
As a core wire, 1,500 denier aramid fiber (trade name: Twaron) is twisted in the upside down direction at 19.7 turns / 10 cm and the bottom twist number 15.8 turns / 10 cm in the upside down direction, and 2 × 3 twist. An unprocessed cord having a total denier of 9,000 was prepared. Next, the untreated cord was pre-dipped with an isocyanate-based adhesive, dried at about 170 to 180 ° C., immersed in an RFL solution, and stretch-heat-set at 200 to 240 ° C. to obtain a treated cord.
[0042]
A molding die equipped with a cylindrical mother die having alternating protrusions and grooves is mounted on a spindle, and a reinforcing cloth is pulled out and placed on the surface of the molding die, A pair of vulcanized rubber is formed by rotating the molding die, fitting an iron rod-shaped member slightly longer than the surface length of the molding die into each groove, pressing the rod-shaped member on each end of the base die. And pressed against the bottom surface of the groove-shaped portion, and wound up with one ply of laminate to complete the molding.
[0043]
Subsequently, a compressed rubber sheet whose end face was cut with a bias was wound on a reinforcing cloth of a molding die, butted against the end faces, and the joints were lightly joined with a stitcher. ２2 kg / cm 2 for 15 seconds).
[0044]
Then, a 0.05-mm-thick polymethylpentene film is wrapped around the surface of the compressed rubber sheet by one ply, further covered with a rubber jacket, placed in a vulcanizer in that state, and heated and pressurized (temperature: 170 ° C., The compressed rubber sheet was molded into the protruding portion and the groove portion of the cylindrical mother die by an external pressure of only 0.8 Mpa for about 7 minutes.
[0045]
Further, the core wire, the adhesive rubber sheet, and the stretched rubber sheet are sequentially wound to form a belt molded body, a jacket is covered, a molding die is set in a vulcanized can, and vulcanized under normal conditions to obtain a belt sleeve. Was. This sleeve was cut into a V shape by a cutter to complete a low-edge cogged belt for a scooter.
[0046]
In the obtained low-edge cogged belt, the position of the joint of the compressed rubber layer could not be specified on the appearance, no cracks occurred, the shape of the cog peak was uniform over the entire circumference, and at the overlap of the reinforcing cloth No wrinkles occurred. Further, in the method of the present invention, since the reinforcing cloth is not molded using an adhesive such as rubber glue on the surface of the molding die, deterioration of the working environment due to volatilization of the organic solvent can be prevented.
【The invention's effect】
As described above, in the invention described in the claims of the present application, the reinforcing cloth is placed on the surface of the molding die having the projecting portions and the groove portions alternately, the rod-shaped member is fitted into the groove portions and pressed, and By successively mechanically fixing the rod-shaped member to the bottom of the groove, the reinforcing cloth can be easily and reliably mechanically molded, and the compressed rubber sheet is wound around the surface of the reinforcing cloth and cut. The surfaces of the compressed rubber sheet are butt-joined, and an anti-adhesive material is wound around the surface of the compressed rubber sheet. Then, the compressed rubber sheet from which each rod-shaped member has been removed is heated and pressed to form a projection and a groove of the molding die. The close contact with the mold eliminates the need for skilled workers to join the rubber and reinforcing cloth at the cog peaks, and also causes cracking and wrinkling of the reinforcing cloth due to insufficient volume of the rubber at the joint. Stabilize product quality by eliminating occurrence Can, even in advance since it is not necessary to prepare a Kogupaddo, have excellent effects such as inlining production allows reduction of work in process becomes possible.
[Brief description of the drawings]
FIG. 1 shows a step of molding a reinforcing cloth into a molding die in the production method of the present invention.
FIG. 2 shows a state in which a reinforcing cloth is molded on the surface of a molding die in the production method of the present invention.
FIG. 3 shows a step of winding a sheet for compressed rubber around a molding die and joining the cut surfaces in abutting manner in the production method of the present invention.
FIG. 4 shows a step of winding an anti-adhesive material around the surface of the compressed rubber sheet in the production method of the present invention.
FIG. 5 shows a step of heating and pressurizing a compressed rubber sheet into a protruding portion and a groove-shaped portion of a molding die in the manufacturing method of the present invention so as to form a mold.
FIG. 6 shows a state in which a sheet for compressed rubber is molded in the production method of the present invention.
FIG. 7 shows a state in which a belt molded body is produced on the surface of a compressed rubber sheet molded in the production method of the present invention.
FIG. 8 is a partial front view of a cogged belt obtained by the manufacturing method of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Molding die 2 Cylindrical mother die 3 Base mold 4 Protrusion part 5 Groove part 6 Reinforcement cloth 7 Bar-shaped member 8 Groove part bottom surface 9 Retaining band 10 Compressed rubber sheet 11 Cut surface 12 Heat press 13 Joint part 15 Adhesion Inhibitor 17 Jacket 20 Compressed rubber layer 30 Core wire 31 Adhesive rubber sheet 34 Reinforcement cloth 35 Belt molding

Claims (8)

Manufacture of a power transmission belt in which at least a compression rubber layer of a compression rubber layer and an extension rubber layer has a cog portion in which cog peaks and cog valleys are alternately arranged, and a core wire is formed to be embedded in the adhesive rubber layer. In the method,
The reinforcing cloth is placed on the surface of the molding die having the protruding portions and the groove portions alternately, the rod-shaped member is fitted into the groove-shaped portion and pressed, and the bar-shaped member is mechanically fixed to the bottom of the groove-shaped portion. After molding the reinforcing cloth by doing
A sheet for compressed rubber that forms a compressed rubber layer is wound around a molding die, the cut surfaces are butt-joined,
After winding the anti-adhesive material around the surface of the compressed rubber sheet, the compressed rubber sheet from which the rod-shaped member has been removed is heated and pressurized and molded into the protrusions and grooves of the molding die,
An unvulcanized compressed rubber sheet from which the anti-adhesive material has been removed is wrapped with an expanded rubber sheet that forms at least a core wire and an expanded rubber layer on the surface of the unvulcanized compressed rubber sheet to form a belt molded body, and then vulcanized. A method for manufacturing a power transmission belt, comprising cutting a sulfuric sleeve into a V shape to produce a power transmission belt. 2. The method for manufacturing a power transmission belt according to claim 1, wherein the means for mechanically fixing each rod-shaped member to the bottom of the groove-shaped portion is a method of pressing the reinforcing cloth against the bottom of the groove-shaped portion by using a holding band. The method according to claim 1, wherein the holding band is an elastic member that is elastically fastened to a molding die. The method for manufacturing a power transmission belt according to any one of claims 1 to 3, wherein the joint portion is overlapped after winding the reinforcing cloth around the molding die. The method for producing a transmission belt according to any one of claims 1 to 3, wherein the reinforcing cloth is a tubular canvas that is highly elastic in a circumferential direction. The method for manufacturing a power transmission belt according to any one of claims 1 to 5, wherein ends of the compressed rubber sheet are butted at a bias cut surface, and the joined portion is joined by heating and pressing. 2. The method according to claim 1, wherein the anti-adhesion material is at least one resin film selected from polymethylpentene and polyethylene terephthalate. An anti-adhesive material is wrapped around the surface of the compressed rubber sheet, the molding die covered with the jacket is placed in a vulcanizing can, and the compressed rubber sheet is heated and pressurized to apply the protrusions and grooves to the molding die. The method for manufacturing a power transmission belt according to claim 1, wherein the power transmission belt is molded by pressing.

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