JP4104903B2 - Manufacturing method of toothed belt - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for manufacturing a toothed belt, and more particularly, a tooth in which a deviation of a reinforcing member adhered to the surface of a tooth portion is eliminated when pressurizing unvulcanized rubber along a gap between an outer mold and a core mold. The present invention relates to a method for manufacturing a belt with a belt.
[0002]
[Prior art]
The toothed belt is composed of a plurality of tooth portions provided along the longitudinal direction on the inner surface side thereof, and a back portion in which a core wire is embedded, along the surface of the tooth portion and the surface of the tooth bottom portion between adjacent tooth portions. The reinforcing member is attached. As the reinforcing member, a weft parallel to the longitudinal direction of the toothed belt and a woven fabric woven so as to intersect with the weft are used.
[0003]
In manufacturing such a toothed belt, the press-fitting method has been conventionally used. That is, after using a cylindrical vulcanization mold formed with a plurality of recesses for forming tooth portions on the outer periphery, a cylindrical reinforcing member is put on the outer periphery of the vulcanization mold, and then a core is formed on the outer side. A wire is wound in a spiral shape, and an unvulcanized rubber sheet is wound around the wire, and this is vulcanized with high-pressure steam. When heated with high-pressure steam in this way, the unvulcanized rubber of the rubber sheet can be pressed into the concave portion of the vulcanizing mold from the gap between the core wires with the steam pressure at that time, and the tooth portion can be molded. An attached belt can be manufactured.
[0004]
Further, when the unvulcanized rubber of the rubber sheet is pressed into the concave portion of the cylindrical mold to form the tooth portion, the reinforcing member is attached to the surface of the tooth portion and the surface of the tooth bottom portion between the tooth portions. Worn.
[0005]
[Problems to be solved by the invention]
However, in such a manufacturing method by the press-fitting method, in order to use a rubber sheet, it is necessary to roll the sheet to a predetermined thickness using a roll, which causes a problem in terms of material cost and the like. . In order to solve this, transfer molding has been proposed in which unvulcanized rubber is press-fitted into a cavity of a mold. In this molding method, flat belts made only of rubber are the mainstream, and when reinforcing members such as canvas are used, there is a problem that the reinforcing members are displaced, and the use of reinforcing members can be avoided. It was.
[0006]
The present invention has been made in view of the above points, and eliminates the displacement of the reinforcing member adhered to the surface of the tooth portion when the unvulcanized rubber is press-fitted along the gap between the outer mold and the core mold. An object of the present invention is to provide a method for manufacturing a toothed belt.
[0007]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a toothed belt manufacturing method in which tooth portions and groove portions are alternately arranged at predetermined intervals along the length direction, a core wire is embedded in the back portion, and the surface of the tooth portion is reinforced. In the manufacturing method of the toothed belt to which the member is adhered,
A cylindrical reinforcement member is attached to the outer periphery of this mold using a tooth mold as a core mold,
A fixing member is fitted into the groove provided on the end surface of the core mold, the end portion of the reinforcing member is installed and fixed , the end surface of the core mold is planar, and the upper end surface is a corner portion,
Spin the core on the reinforcing member,
Install the core mold in the outer mold, press the unvulcanized rubber into the cavity of the outer mold and the core mold, heat vulcanize,
It consists of a step of taking out the belt sleeve from the core die taken out from the outer die.
That is, in the present invention, since the end portion of the reinforcing member is mechanically fixed to the end surface of the core mold, even if unvulcanized rubber is press-fitted into the gap between the outer mold and the core mold, the reinforcing member is not displaced. In addition, since accurate teeth and back portions can be molded, it is not necessary to polish the back surface as in the prior art.
Further, this makes it possible to smoothly press-fit the unvulcanized rubber into the cavity between the outer mold and the core mold without remaining from the end face of the core mold.
[0009]
Invention of Claim 2 of this application exists in the manufacturing method of the toothed belt whose reinforcement member is a knitted fabric or a textile fabric.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
[0011]
FIG. 1 is a cross-sectional view of a toothed belt manufacturing apparatus, FIG. 2 is a cross-sectional view of the toothed belt manufacturing apparatus in operation, and FIG. FIG. 4 is a schematic view of the previous state, and FIG. 4 is a schematic view of the state after the end portion of the reinforcing member is installed and fixed to the core mold.
According to this, in the toothed belt manufacturing apparatus 1 used in the present invention, the outer mold 2 provided with the accommodating portion 4 of the core mold 3 is disposed at the center, and the core mold 3 is installed below the outer mold 2. The cradle 5 is combined. The outer die 2 has a structure in which an exchangeable conical inner die 2a and an outer die 2b arranged inside are combined, and the inner die 2a is used when changing the outer peripheral length and thickness of the toothed belt formed together with the core die 3. Can be replaced. In addition, a heating unit 7 for putting a heat medium such as steam or oil is provided on the outer periphery of the outer mold 2.
[0012]
The core mold 3 is inserted into the housing portion 4, the core mold lower protrusion 8 is inserted into the recess 9 of the cradle 5, and the core mold 3 is stably installed, and between the outer mold 2 and the core mold 3. A cavity 10 is formed. On the other hand, the upper protruding portion 11 of the core mold 3 is positioned in the reservoir portion 12 in which the heated unvulcanized rubber 6 is accommodated. Then, when a flat plate-shaped upper mold 15 fitted with the press-fit piston 14 is placed on the upper surface of the outer mold 2 and the upper mold 15 is pressurized by a press machine, the unvulcanized rubber 6 accommodated in the reservoir 12 flows. The cavity 10 is filled. In this case, if the inside of the cavity 10 is evacuated, the flow of the unvulcanized rubber 6 can be improved, and the generation of voids can be prevented.
[0013]
As shown in FIG. 3, the core mold 2 has a belt molding portion 19 in which concave portions 17 and convex portions 18 are alternately arranged, and upper and lower protrusions 11 and 8 at both ends. A circular groove 21 is provided outside the protrusions 11 and 8. Then, as shown in FIG. 4, the fixing member 22 is fitted into the groove portion 21 so that the end portion 24 of the reinforcing member 23 is installed and fixed, and the reinforcing member 23 is prevented from generating wrinkles. And the core type | mold 3 with which the said reinforcement member 23 was mounted | worn is installed in a spinning apparatus, and the core wire 25 which consists of fiber cords is wound helically.
[0014]
In the toothed belt manufacturing method of the present invention, first, as shown in FIG. 3, the belt molding portion 19 of the core mold 3 is covered with a cylindrical reinforcing member 23 and the end portion 24 of the reinforcing member is attached to the end face 20. , 20, and after being inserted into the groove 21, the fixing member 22 is fitted into the groove 21 and fixed, and then the core wire 25 is wound. The end surface 20 after the fixing member 22 is inserted becomes a flat surface without unevenness, the unvulcanized rubber 6 is easy to flow smoothly, and the reinforcing member 23 does not generate wrinkles.
Further, a corner portion 27 is provided on the upper end surface 20 to facilitate the flow of the unvulcanized rubber 6 into the cavity 10.
[0015]
The reinforcing member 23 is attached to fix the end portion 24, and the lower projection 8 of the core mold 3 around which the core wire 25 is wound is fitted into the recess 9 of the cradle 5. After a predetermined amount of unvulcanized rubber 6 heated to 80 to 130 ° C. is stored in the reservoir 12 after being installed and fixed on the flat plate, the flat upper die 15 fixed to the press machine is lowered to insert the press-fit piston 14 into the core die. The cavity 10 is filled with the unvulcanized rubber 6 while being inserted into the upper projection 11 of the third. At this time, the unvulcanized rubber 6 flows into the concave portion 17 from the gap between the core wires, and at the same time, the reinforcing member 23 is pressed against the side wall of the concave portion 17 to be brought into close contact therewith.
[0016]
Then, a heat medium is poured into the heating part 7 provided in the outer peripheral part of the outer mold 2, and the outer mold 2 is heated at 150 to 170 ° C. for 15 to 25 minutes to vulcanize the unvulcanized rubber 6. In this case, a heater can be inserted into the core mold 3 for heating.
[0017]
When the vulcanization is completed, the upper die 15 is raised, the core die 3 is taken out from the cradle 5, the fixing member 22 is removed from the groove portion 21, and then the belt sleeve 29 is taken out from the core die 2. After the belt sleeve 29 is cooled, a toothed belt can be obtained by cutting the belt sleeve 29 into a predetermined width.
[0018]
The reinforcing member 23 is a base fabric selected from a woven fabric, a knitted fabric, a non-woven fabric, and the like. As the fiber material constituting the base fabric, known materials can be used. For example, natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamides, polyesters, polyethylenes, polyurethanes, polystyrenes, Examples include organic fibers such as fluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester, and aramid, and it is preferable to use a woven fabric in which these are woven into plain weave, twill weave, satin weave, or the like.
[0019]
The form of the fiber is not limited to a spun yarn, a multifilament yarn, a monofilament yarn, etc. Good wear resistance and tooth chipping resistance. In addition, it is an effective means for reducing the surface friction coefficient to lower the weave density or to use a fiber having a large diameter.
In the case of the present invention, shrinkage is required in the weft direction of the base fabric because of the press-fitting method. For this reason, it is preferable to use a crimped 6 nylon, 66 nylon, or a composite yarn twisted with a urethane elastic yarn as the weft along the longitudinal direction of the belt body. When monofilament yarn is used for the base fabric, it is desirable to use it for warp yarn so as not to affect the shrinkage in the weft direction.
[0020]
The base fabric is immersed in a resorcin-formalin-latex liquid (RFL liquid) according to a known technique, and then friction is applied by rubbing the unvulcanized rubber into the base cloth. Immerse in the liquid. Moreover, you may perform an adhesion | attachment process only with RFL liquid.
[0021]
The RFL liquid is a mixture of resorcin and formalin initial condensate and rubber latex, and the molar ratio of resorcin and formalin is preferably 1: 0.5 to 3 in order to increase the adhesive force. The initial condensate of resorcin and formalin is mixed with the latex so that the resin content is 10 to 100 parts by weight with respect to 100 parts by weight of the latex rubber, and the total solid concentration is 5 to 40. % Concentration is adjusted. The RFL solution may be appropriately mixed with a carbon black solution to blacken the treatment, or a known surfactant may be added in an amount of 0.1 to 5.0% by weight.
Examples of the latex include styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer, EPDM, and the like. Latex.
[0022]
The unvulcanized rubber 6 used here is natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene (ACSM), nitrile. A rubber selected from rubber (NBR), hydrogenated nitrile rubber (H-NBR), hydrogenated nitrile rubber blended with unsaturated carboxylic acid metal salt, ethylene propylene diene monomer (EPDM), butyl rubber (IIR), etc. Or blended. Alternatively, it is possible to use polyurethane rubber in addition to these rubbers. In particular, in the case of a toothed belt, it is desirable to use a rubber having improved heat aging resistance. In the case of a hydrogenated nitrile rubber, the hydrogenation rate is 80% or more, and the heat resistance and ozone resistance characteristics are exhibited. For that purpose, 90% or more is more preferable. Hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance.
[0023]
In the unvulcanized rubber 6, a reinforcing agent such as carbon black, a filler, a softening agent, an anti-aging agent, a vulcanizing aid, a vulcanizing agent such as sulfur or an organic peroxide, and the like are added. Mixed. When an organic oxide is blended as a crosslinking agent, 0.2 to 10 mass of organic peroxide is added to 100 mass parts of the polymer component in order to ensure a predetermined modulus (tensile modulus) and elongation at break. It is necessary to mix partly and crosslink. The organic peroxide is not particularly limited. In addition to such organic peroxides, metal oxides, sulfur compounds, oxime nitroso compounds, monomers, and polymers that are commonly used as co-crosslinking agents may be added in appropriate amounts.
[0024]
The core wire 25 is a cord made of polyparaphenylene benzobisoxazole fiber (PBO fiber), aramid fiber, and glass fiber, and the composition of the glass core wire may be either E glass or S glass (high strength glass), filament It is not limited to the thickness of the fiber, the number of filaments converged and the number of strands. Further, it is not limited to a sizing agent, RFL, overcoat agent or the like used as an adhesive treatment agent or a protective material for a glass filament during bending.
[0025]
The core wire 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 a resorcin-formalin-latex (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 also a method of performing a pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.
[0026]
【Example】
Next, the present invention will be specifically described with reference to examples.
[0027]
Chloroprene rubber composition (100 parts by mass of chloroprene, 4 parts by mass of magnesia, 15 parts by mass of zinc, 2 parts by mass of vulcanization accelerator, 0.5 parts by mass of sulfur, 2 parts by mass of anti-aging agent, carbon black as unvulcanized rubber 65 parts by mass and 8 parts by mass of oil) were used. As the base fabric, 210d / 1 nylon filament yarn for warp and double twisted yarn consisting of 40d / 5 wooly nylon yarn for weft are used, and weaving structure (warp 140 / 3cm, weft 100 / 3cm) A 2/2 twill canvas consisting of After weaving, the canvas is vibrated in water to shrink it to about half the width during weaving, and then the rubber composition using the unvulcanized rubber is dissolved in methyl ethyl ketone at a predetermined ratio. After being immersed in the rubber paste and dried, vulcanized at 153 ° C. for 30 minutes, and 0.9 mm treated canvas was used as a tooth cloth. In this case, the canvas used the weft direction in the longitudinal direction of the belt.
[0028]
Further, about 600 glass fiber filaments having a strand diameter of about 9 μm are bundled as a core wire to form a strand. About 4,000 parts by weight of latex, 1,100 parts by weight of SBR latex, 5,500 parts by weight of water, dried at 200 ° C. for 2 minutes, and then twisted with 16.0 times / 10 cm twist number A 0.3 mm cord was used.
[0029]
Then, an endless cylindrical base fabric having a weft thread in the circumferential direction is attached to the core mold so that the warp runs along the width direction of the belt, and the end portion of the base fabric is bent at the end surface of the core mold to form a ring shape. After entering the groove, the fixing member was fitted into the groove and fixed. And the core type | mold was installed in the spinning apparatus and the said core wire was wound from on the base fabric.
[0030]
After the core mold is inserted into the outer mold and installed, the unvulcanized rubber heated at 130 ° C. is stored in the reservoir, and then the flat upper mold fixed to the press is lowered and the unvulcanized rubber is pressed by the press-fit piston. The cavity was filled while pressurizing. Then, the pressurized steam was put into the heating part of the outer mold, and the outer mold was heated at 165 ° C. for 20 minutes to complete the vulcanization process. Then, after removing the core mold from the outer mold, it was taken out from the core mold, and a belt sleeve having a tooth profile S3M having 70 teeth, a pitch of 3 mm, and a circumferential length of 210 mm was obtained.
[0031]
As a result, the tooth portion of the belt sleeve appeared accurately and no wrinkles of the base fabric were generated.
[0032]
【The invention's effect】
As described above, the manufacturing method of the toothed belt according to the present invention claims that the tooth mold is used as a core mold, and a cylindrical reinforcing member is mounted on the outer periphery of the mold, and is fixed to the groove provided on the end surface of the core mold. Fit the member, install and fix the end of the reinforcing member, spin the core wire on the reinforcing member, install the core mold in the outer mold, and unvulcanized rubber between the outer mold and the core mold This is a process of removing the belt sleeve from the core taken out from the outer mold by press-fitting into the cavity of the core and mechanically fixing the end of the reinforcing member to the end face of the core mold. Even if it press-fits into the gap between the mold and the core mold, an accurate tooth portion can be molded without causing the displacement of the reinforcing member.
[0033]
In addition, the end portion of the reinforcing member is fixed by fitting the fixing member into the groove portion provided on the end surface of the core mold, and the end surface of the core mold is planarized, whereby the unvulcanized rubber is removed from the core mold. There is an effect that it can be smoothly press-fitted into the cavity of the outer mold and the core mold without remaining from the end face.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an apparatus for manufacturing a toothed belt used in the present invention.
FIG. 2 is a cross-sectional view when the toothed belt manufacturing apparatus shown in FIG. 1 is operated;
FIG. 3 is a schematic view of a state before the end portion of the reinforcing member is installed and fixed to the core mold.
FIG. 4 is a schematic view of a state after the end portion of the reinforcing member is installed and fixed to the core mold.
FIG. 5 is a perspective view of the obtained belt sleeve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus of a toothed belt 2 Outer mold | type 2a Internal mold | type 2b External mold | type 3 Core type | mold 4 Accommodating part 5 Receptacle 6 Unvulcanized rubber 7 Heating part 10 Cavity 12 Reserving part 21 Groove part 22 Fixing member 23 Reinforcement member 24 End part 25 Core 29 belt sleeve

Claims (2)

In the method for manufacturing a toothed belt in which teeth and grooves are alternately arranged at predetermined intervals along the length direction, the core wire is embedded in the back, and a reinforcing member is attached to the surface of the tooth,
The tooth mold is a core mold, and a cylindrical reinforcing member is attached to the outer periphery of the mold.
A fixing member is fitted into the groove provided on the end surface of the core mold, the end portion of the reinforcing member is installed and fixed , the end surface of the core mold is planar, and the upper end surface is a corner portion,
Spin the core on the reinforcing member,
Install the core mold in the outer mold, press the unvulcanized rubber into the cavity of the outer mold and the core mold, heat vulcanize,
Take out the belt sleeve from the core mold taken out from the outer mold,
The manufacturing method of the toothed belt characterized by the above-mentioned.   The method for producing a toothed belt according to claim 1, wherein the reinforcing member is a knitted fabric or a woven fabric.

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