JP2008006713A - Manufacturing method for double-sided toothed belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a double-sided toothed belt causing few failures which can align the position of the tooth part of an inner and outer peripheral surface in such a state that the position between a rubber sheet composing the belt and a mold is determined, and can match the position and a pitch of the tooth part of a belt sleeve whole periphery by positioning one time. <P>SOLUTION: The manufacturing method molds a belt sleeve S where an inner tooth part is formed on the inner peripheral surface by winding, heating, and pressurizing, on a cylindrical inner mold 50 having protruded and recessed portions 51 for forming the tooth form on the outer peripheral surface. Thee belt sleeve is inserted into the cylindrical outer mold 54 which has an inside diameter larger than a belt size and protruded and recessed portions 55 for forming the tooth form on the inner peripheral surface in such a state that the belt sleeve is mounted to the inner mold 50. The belt sleeve is held with the outer mold 54 in such a state that the pitches of the inner tooth and the recessed and protruded portions 51, 55 of the inner surface of the outer mold, and both are relatively rotated while being heated and pressurized, and the outer tooth part is formed on the outer surface of the belt sleeve. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a double-sided toothed belt having teeth on both inner and outer peripheral surfaces of the belt, and more specifically, when forming teeth on the belt, it is easy to match the period of the teeth on the inner and outer surfaces. The present invention relates to a method for manufacturing a double-sided toothed belt excellent in workability.

  The double-sided toothed belt is a belt having tooth portions on the inner surface and the outer surface, and usually the upper and lower tooth portions are provided at the same pitch. Double-sided toothed belts are used for office equipment, OA equipment, conveying devices, etc., and are also used as belts for continuously variable transmissions.

  The belt used in the belt type continuously variable transmission is used by being wound around a transmission pulley that changes the effective diameter of the pulley by adjusting the V groove width of the pulley and adjusts the transmission gear ratio. Because the side pressure from the belt increases, the belt must withstand a large side pressure. In addition to a continuously variable transmission, a belt that can withstand a high load needs to be used for a high load transmission where the life of a normal rubber belt is too short.

  Among such belts, there is a high-load transmission belt in which a block is fixed to the center belt to increase the strength in the belt width direction. The specific structure is that the core is made of rubber or other rubber. In the center belt embedded in the center belt, a fixing material such as a bolt or a rivet is used to fix and fix a block that is relatively harder than the rubber used for the center belt. There is a belt having a groove on the surface and a pair of center belts fitted in the groove provided on the side surface.

  The center belt used for such a belt is a member that bears tension, and a high-strength and low-stretch core wire is embedded in rubber, and a recess for fitting with a block is formed on the inner and outer peripheral surfaces of the center belt. It is a double-sided toothed belt in which convex portions are provided alternately. For example, convex portions are provided in the grooves on both sides of the block at positions corresponding to the concave portions of the center belt, and the blocks do not move in the traveling direction of the high-load transmission belt with respect to the center belt by fitting with each other. It is fixed.

  Conventionally, as shown in Patent Document 1, an unvulcanized rubber sheet is wound around a cylindrical inner mold having a tooth profile on the outer peripheral surface, and has a toothed portion on the inner peripheral surface in a cylindrical shape. By forming the outer mold around the inner mold, the unvulcanized rubber is heated and pressed between the inner mold and the outer mold to mold and vulcanize the teeth on both the inner and outer surfaces, and can be divided. There is a manufacturing method in which the outer sleeve is disassembled and the belt sleeve is removed.

  In addition, in the manufacture of double-sided toothed belts having teeth on both sides of the inner and outer peripheral surfaces of the belt, the rubber is flowed by first wrapping an unvulcanized rubber sheet around a cylindrical mold having a tooth shape and applying heat and pressure. First, a belt sleeve having a tooth portion on the inner peripheral surface is formed, and then the belt sleeve is removed from the mold, and a pair of flat surfaces having a tooth shape on one side is formed. Using a mold, a part of the belt sleeve is brought into contact with the mold to form a tooth profile on the outer peripheral surface side and vulcanize, and the position for molding and vulcanization is moved forward to move the belt in a plurality of operations. The outer teeth of the entire sleeve were molded and vulcanized. Thereafter, the production of the double-sided toothed belt was completed by cutting the belt sleeve to a predetermined width as required. A belt manufacturing method according to such a procedure is described in, for example, Patent Document 2.

JP-A-1-171934 Japanese Patent Laid-Open No. 10-34767

  The manufacturing method using a split mold as the outer mold described in Patent Document 1 has the advantage that the tooth profile on the belt inner peripheral surface and the tooth profile on the belt outer peripheral surface can be formed in a single step. There are problems that the mold structure is complicated and the mold production cost is high, and that the belt tooth shape of the divided part of the divided mold is difficult to be a regular shape.

  On the other hand, in the manufacturing method in which the tooth portion on the inner peripheral side of the belt is formed with a cylindrical mold disclosed in Patent Document 2 and then the tooth shape on the outer peripheral surface is formed with a flat press, the above-mentioned Patent Document There is no problem like 1 but when forming the tooth profile on the inner peripheral surface, the cylindrical inner mold is used, and then when forming the tooth profile on the outer peripheral surface, the belt sleeve is removed from the inner mold. And it shape | molds using a pair of flat metal mold | die which has a tooth form. Therefore, it is necessary to align the positions of the tooth portions on the inner and outer peripheral surfaces and the tooth spaces between the tooth portions with the pair of upper and lower molds in the removed belt sleeve. Moreover, in order to form the tooth portion on the entire circumference of the belt sleeve, it is necessary to perform a plurality of presses, and it is also necessary to perform alignment when the tooth portion is provided on the outer peripheral surface. Further, in the case of a flat plate-shaped mold, it is difficult to align, and in particular, a sleeve having a long surface length is cut for alignment. In addition, since the relative position between the belt sleeve and the mold is not fixed until the moment of pressing between the upper and lower molds, there has been a problem that a displacement occurs in the pressing process.

  Therefore, in the present invention, the tooth portions on the inner and outer peripheral surfaces can be aligned in a state where the positions of the rubber sheet and the mold constituting the belt are determined, and the positions of the tooth portions on the entire circumference of the belt sleeve can be obtained by one alignment. Another object of the present invention is to provide a method for manufacturing a double-sided toothed belt that can be combined with a pitch and has few defects.

  In order to achieve the above object, in claim 1 of the present invention, in a method for manufacturing a double-sided toothed belt having teeth on both sides of a belt body made of vulcanized rubber, irregularities for forming a tooth profile on the outer peripheral surface A rubber sheet is wound around a cylindrical inner mold having a shape and heated and pressed to form a belt sleeve having an inner tooth portion formed on the inner peripheral surface, and then the belt sleeve is mounted on the inner mold. Inserted into a cylindrical outer mold having an inner diameter larger than the size and having irregularities for forming a tooth profile on the inner peripheral surface, and between the inner mold and the outer mold with the pitch of the irregularities on the inner surface of the outer mold matched It is characterized in that both are relatively rotated while being sandwiched and heated and pressed to form an external tooth portion on the outer surface of the belt sleeve.

  The double-sided toothed belt according to claim 2, wherein a rubber sheet constituting the outer tooth portion is wound around the surface of the belt sleeve having the inner tooth portion formed on the inner peripheral surface of the inner die, and the outer tooth portion is formed by the outer die. The manufacturing method.

  In claim 3, the outer mold has an inner diameter larger than the belt size, and a rubber sheet for external teeth is attached to the inner peripheral surface of a cylindrical outer mold having irregularities for forming a tooth profile on the inner peripheral surface. In the manufacturing method of the double-sided toothed belt, the belt sleeve having the inner teeth formed on the inner peripheral surface is inserted into the outer mold and the outer teeth are formed by the outer mold.

  The inner and outer teeth are kept in a state in which a rubber sheet is meshed with an outer mold having a size larger than the diameter of the belt while the belt sleeve having a tooth portion formed on the inner peripheral surface is mounted on the inner mold. By aligning the portions, the alignment process is facilitated and the occurrence of defects can be reduced.

  In claim 2, the rubber sheet as a material constituting the external tooth portion is arranged on the belt sleeve side attached to the inner mold, and by aligning the irregularities of the inner mold with the irregularities of the outer mold, A double-sided toothed belt in which the position of the tooth portion and the pitch coincide with each other on the inner and outer peripheral surfaces of the belt can be obtained.

  In the third aspect of the present invention, the position of the tooth portion on the inner and outer peripheral surfaces of the belt can be adjusted by aligning the concave and convex portions of the inner die and the outer die with the material constituting the outer tooth portion attached to the inner surface of the outer die. A double-sided toothed belt with matching pitch can be obtained.

  FIG. 1 is a perspective sectional view of a double-sided toothed belt manufactured by the method of the present invention. FIG. 2 is a schematic perspective view showing an example of a high load transmission belt 1 using a center belt having teeth on both sides manufactured by the method of the present invention, and FIG. 3 is a side view of the high load transmission belt. .

  A toothed belt 1 shown in FIG. 1 has a plurality of external teeth 2 and internal teeth 3 arranged along the length direction, and a core wire 4 is arranged between the teeth 2 and 3, A cover canvas 5 is covered on the surfaces of the tooth portions 2 and 3. A rubber layer 6 is usually coated on the inside of the cover canvas 5.

  The raw rubber used for both the inner and outer teeth 2, 3 is hydrogenated nitrile rubber, chloroprene rubber, chlorosulfonated polyethylene, alkylated chlorosulfonated polyethylene and other rubbers with improved heat aging resistance, natural rubber Tolyl rubber or the like is used for rubber, styrene butadiene rubber, or the like. In the above rubber, carbon black, zinc white, stearic acid, plasticizer, anti-aging agent, etc. are added as compounding agents, and sulfur and organic peroxides are added as vulcanizing agents. The vulcanizing agent is not particularly limited.

  As the core wire 4, a glass rope treated with an RFL solution or rubber paste, or an organic fiber such as an aramid fiber rope treated with an adhesive such as an RFL solution, an epoxy solution, an isocyanate solution and rubber paste, or the like. Used.

  FIG. 2 shows a high-load transmission belt 11 using a center belt having teeth on both sides manufactured by the manufacturing method of the present invention, and a rope-like core wire 15 is embedded in a spiral in a rubber 14. The two center belts 13a and 13b having the same width and the block 12 having grooves 16 and 17 for fitting the center belts 13a and 13b on the side surfaces 12a and 12b.

  Teeth portions 20 and 21 are formed on the upper and lower surfaces 18 and 19 of the center belts 13a and 13b at a predetermined pitch, and the concave strip portions 22 and 23 between the tooth portions 20 and 21 are formed in the grooves 16 and 17 of the block 12. As will be described later in FIG. Both block side surfaces 12a and 12b of the block 2 are inclined surfaces that engage with the V-grooves of the pulleys, and receive the power from the driven pulleys, and are locked and fixed to the center belts 13a and 13b. The power of the driving pulley is transmitted to the driven pulley. Cover canvases 22 and 23 are laminated on the upper and lower surfaces of the center belts 13a and 13b.

  As shown in FIG. 2, the block 12 includes an upper beam portion 24 and a lower beam portion 25, and a center pillar 26 in which the central portions of the upper and lower beam portions 24 and 25 are connected to each other. Grooves 16 and 17 into which the center belts 13a and 13b are fitted are formed. Further, as shown in FIG. 3, on the upper and lower surfaces of the groove in the groove 16, a convex strip portion 27 that engages a concave strip portion 22 provided on the upper surface 18 of the center belt 13 and a concave strip portion 23 provided on the lower surface 19 28 is provided, whereby the block 12 and the center belts 13a and 13b are locked and fixed.

  As the block resin, polyamide resin, polyamideimide (PAI) resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polyimide (PI) resin, polyethersulfone (PES) resin, Synthetic resins such as polyetheretherketone (PEEK) resin are used, but among them, they have low friction coefficient, excellent wear resistance, rigidity and elasticity against bending, and can be easily damaged. Resin which does not end up is good, and it can be said that polyamide resin, especially 4,6-nylon is preferable.

  In the present invention, it is possible to mix a fibrous reinforcing material and a whisker-shaped reinforcing material in the synthetic resin forming the block as described above, and the fibrous reinforcing material is blended in the range of 15 to 40% by weight. To do. If it is less than 15% by weight, there is a problem that the reinforcing effect is small and the wear resistance of the block is not sufficient, and if it exceeds 40% by weight, it becomes difficult to mix with resin or injection molding becomes difficult. Because there is a problem, it is not preferable.

  Examples of the fibrous reinforcing material to be blended with the synthetic resin include aramid fibers, carbon fibers, glass fibers, polyamide fibers, and polyester fibers. Among them, the resin that constitutes the block described above is a preferable example of using 4,6-nylon and carbon fiber in combination with carbon fiber to improve the water-absorbing defect of 4,6-nylon and greatly improve the rigidity. It is possible to make use of the wear resistance, impact resistance and fatigue resistance of 4,6-nylon.

  Moreover, you may mix | blend inorganic fibers, such as a zinc oxide whisker, a potassium titanate whisker, an aluminum borate whisker other than said organic fiber as said fibrous reinforcement.

  Moreover, since the zinc oxide whisker has a high specific gravity and high rigidity, it is possible to reduce vibration during contact with the pulley and to reduce noise generation. In addition, when there are few compounding quantities of this zinc oxide whisker, the added effect is not expressed, and when too large, it cannot knead | mix and it becomes difficult to shape | mold.

  By adopting such a material structure, it has strength such as rigidity and toughness that can sufficiently withstand the side pressure received when it comes into contact with the pulley, has excellent wear resistance, and further, with respect to heat generated during friction. The power received from the pulley can be efficiently transmitted to the center belts 13a and 13b as a tensile force, and a tension transmission type high load transmission belt can be configured.

  In addition to these, the lubricity of the block 12 can also be improved by mixing at least one selected from molybdenum disulfide, graphite, and fluororesin. Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), polyfluorinated ethylene propylene ether (PFPE), tetrafluoroethylene hexafluoropropylene copolymer (PFEP), polyfluorinated alkoxyethylene (PFA), and the like. .

  What is used as the rubber 14 of the center belts 13a and 13b is a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, rubber appropriately blended with these materials, polyurethane rubber, or the like. Can be mentioned. As the core body 15, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used.

  The canvas used as the belt cover canvas is 6-nylon, 6,6-nylon, polyester, aramid fiber, etc., and may be used alone or in combination. The warp and weft yarns of the cover canvas are also filament yarns or spun yarns of the fibers, and the woven constitution may be any of plain fabrics, twill fabrics, and satin fabrics. In addition, it is preferable to use a part of elastic urethane elastic yarn for the weft.

  In the manufacturing method of a toothed belt having teeth on both the inner and outer surfaces as described above, in the present invention, as shown in FIG. 4, a cylindrical inner mold having irregularities 51 for forming teeth on the outer peripheral surface. 50, the cover canvas 5 and the core wire 4 are wound in a spiral shape, and then a rubber sheet 52 for constituting the tooth portion of the inner peripheral surface of the belt is wound, and the teeth are formed using a vulcanizing can (not shown). The belt sleeve S is formed by forming the portion and vulcanizing or semi-vulcanizing to form the tooth portion only on the inner peripheral surface (FIG. 5). In the case of semi-vulcanization, when it approaches that state, the internal pressure and temperature of the vulcanizer can be lowered so that vulcanization does not proceed any further. The semi-vulcanization means a state in which each physical property value reaches 1 to 5% when each physical property value such as tensile strength, modulus, and elongation at the time of optimal vulcanization is 100. In this case, as a guideline for optimum vulcanization, the tensile strength is a point slightly beyond the maximum value, the modulus is a point slightly before the maximum value, and the elongation is a point slightly before the minimum value. Judged from the curve.

  Next, with the belt sleeve S having the tooth portion formed only on the inner peripheral surface attached to the inner mold, the rubber sheet 53 and the cover canvas for forming the tooth portion of the belt outer peripheral surface are wound around the surface. And it inserts in the heated outer mold | type 54 which has an internal diameter larger than the size of a belt (FIG. 6). The outer mold 54 has irregularities 55 for forming teeth on the outer peripheral surface of the belt on the inner surface. The rubber sheet 53 is poured into the unevenness 55 by pressing the inner mold 50 against the outer mold 54 while the positions of the unevenness 51 on the outer surface of the inner mold 50 and the unevenness 55 on the inner surface of the outer mold 54 are aligned. The tooth portion of the outer peripheral surface of the belt sleeve S is formed.

  FIG. 7 is a view in which teeth are formed on the outer peripheral surface of the center belt used in the high load transmission belt shown in FIG. The belt sleeve S is rotated by rotating the inner mold 50 within the outer mold 54 or rotating the outer mold 54 around the inner mold 50 while sandwiching the belt sleeve S between the inner mold 50 and the outer mold 54 in this manner. Complete the formation and vulcanization of the teeth on the outer peripheral surface all around.

  By forming teeth on the inner and outer peripheral surfaces of the belt in this way, the inner and outer circumferences of the belt sleeve S are entirely aligned by first aligning the concave and convex portions of the cylindrical inner mold and the outer mold. Since the alignment of the tooth portions of the surface can be performed, the alignment operation can be performed relatively easily and the occurrence of defects due to the alignment failure can be greatly reduced.

  In the method described above, after forming the teeth on the inner peripheral surface of the belt with the inner mold, a rubber sheet for forming the outer teeth is wound around the outer surface of the belt sleeve S and inserted into the outer mold. The teeth are molded and vulcanized, but a rubber sheet for forming the outer teeth is attached to the inner surface of the outer mold, and the belt sleeve S attached to the inner mold is inserted into the outer mold. It is also possible to adopt such a method.

  Similarly, in the method in which a rubber sheet for forming an external tooth portion is attached to the inner surface of the outer mold in advance, the rubber sheet is sandwiched between the outer mold and the inner mold with a certain pressure. By rotating the inner mold or rotating the outer mold around the inner mold, the formation and vulcanization of the outer teeth of the entire circumference of the sleeve can be completed. The alignment of the inner and outer tooth portions over the entire circumference of the belt sleeve S can be performed by first performing the alignment of the concave and convex portions of the outer mold only once.

  When providing a cover canvas on the surface of the tooth portion, use a canvas using a spanned yarn having elasticity as the weft which is the longitudinal direction of the belt, and place it on the mold side of the rubber sheet forming the inner and outer tooth portions, When rubber has fluidity by heating and pressurizing and flows into the recess of the mold, the weft is stretched by the pressure of the rubber and is arranged on the tooth surface along the unevenness of the mold.

  The cover canvas 5 is treated only with the RFL solution, and the solid content of the RFL solution obtained by drying the RFL solution is 30 to 50% by mass. The solid content of the RFL liquid is composed of a solid content of resin and latex. This RFL liquid is obtained by mixing an initial condensate of resorcin and formalin in latex, and the mass% ratio of the initial condensate of resorcin and formalin and latex is 1: 1-10. The latex used here is a latex of styrene-butadiene-vinylpyridine terpolymer, hydrogenated nitrile rubber, chlorosulfonated polyethylene, epichlorohydrin, or the like.

  As a specific treatment method for the cover canvas 5, the canvas is dipped in an RFL solution, dipped with a pair of rolls at a squeezing pressure of about 0.3 to 0.8 kgf / cm (gauge pressure), and then dried. The same RFL liquid was applied, and the solid content adhesion amount of the RFL liquid adhering to the canvas was adjusted to 10 to 50% by mass. If the amount of solid content of the RFL liquid is less than 10% by mass, the contact portion between the warp and weft of the canvas becomes easy to move, and the opening expands. May be exposed to the surface of the part. On the other hand, if the solid content adhesion amount of the RFL liquid exceeds 50%, there is a problem that the solid content adhesion amount increases and the shape of the tooth portion of the belt does not appear accurately.

  The inner surface of the cover canvas 5 treated with the RFL solution is spread with a rubber paste in which a rubber composition mainly composed of raw rubber used for the inner and outer teeth 2 and 3 is dissolved in a solvent. The rubber layer 36 having a thickness of 0.1 to 0.3 mm is formed by drying at a temperature of 100 to 160 ° C. for 30 to 60 seconds. When the thickness of the rubber layer 36 is less than 0.1 mm, the unvulcanized rubber sheet oozes out to the surface of the cover canvas during press vulcanization, and when the thickness exceeds 0.3 mm, the cover canvas of the unvulcanized rubber sheet Even if oozing to the surface is prevented, the outer and inner PLD values are different. This is because the rubber layer 6 is deformed in order to wrap the core wire 3 around the rubber layer 6 of the inner cover canvas 5. In addition, it is preferable to coat the rubber layer 6 on the inner surface of the cover canvas 5 coated on the surfaces of both the inner and outer teeth in order to make the PLD values of both the inside and outside coincide.

  FIG. 7 is a view showing a manufacturing process of a center belt having teeth on both surfaces used for the high load transmission belt 11 shown in FIGS. A center belt having teeth on both sides is made through these steps, and the block 12 is fitted into the recesses 22 and 23 of the obtained center belt, so that the block 12 is finally meshed with the entire circumference. Thus, a high load transmission belt 11 can be obtained.

  The present invention easily matches the pitch of the tooth portion of a double-sided toothed belt or a normal double-sided toothed belt as a tension body of a belt equipped with a block used for driving an automobile, a motorcycle, a general industrial machine, an agricultural machine, etc. It can be used as a manufacturing method with less occurrence of defects.

It is a perspective schematic diagram showing an example of the high load transmission belt concerning the present invention. It is a side view of a high load power transmission belt. It is a side view of a double-sided toothed belt. It is the side view of the place which wound the material for shape | molding a tooth | gear part on an inner peripheral surface to an inner type | mold. It is a side view when the tooth part is formed on the inner peripheral surface of the inner mold. FIG. 6 is a side view of an inner mold and an outer mold where a belt sleeve is sandwiched to form a tooth portion on the outer peripheral surface. It is the side view of the place which formed the tooth | gear part of the outer peripheral surface of the center belt used for the belt of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toothed belt 2 External tooth part 3 Internal tooth part 4 Core wire 5 Cover canvas 6 Rubber layer 11 High load transmission belt 12 Block 12a Side surface 12b Side surface 13a Center belt 13b Center belt 14 Rubber 15 Core wire 16 Groove 17 Groove 18 Upper surface 19 Lower surface 20 Tooth part 21 Tooth part 22 Concave part 23 Concave part 24 Upper beam part 25 Lower beam part 26 Center pillar 27 Convex part 28 Convex part 50 Inner mold 51 Concavity and convexity 52 Rubber sheet 53 Outer mold 55 Concavity and convexity S sleeve

Claims (3)

  In a method of manufacturing a double-sided toothed belt having teeth on both sides of a belt body made of vulcanized rubber, a rubber sheet is wound around a cylindrical inner mold having an uneven shape that forms a tooth profile on the outer peripheral surface and heated and pressurized. A belt sleeve having an inner tooth portion formed on the inner peripheral surface, and then having an inner diameter larger than the belt size while the belt sleeve is mounted on the inner mold and having an unevenness forming a tooth profile on the inner peripheral surface. The outer surface of the belt sleeve is inserted into a cylindrical outer mold and sandwiched between the inner mold and the outer mold in a state where the uneven pitch of the inner surface of the outer mold is matched, and both are rotated relatively while being heated and pressurized. A method for producing a double-sided toothed belt, wherein an external tooth portion is formed on the belt.   2. A double-sided toothed belt according to claim 1, wherein a rubber sheet constituting the outer tooth portion is wound around the surface of a belt sleeve having an inner tooth portion formed on the inner peripheral surface of the inner die, and the outer tooth portion is formed by the outer die. Manufacturing method. The rubber sheet for external teeth is attached to the inner peripheral surface of the cylindrical outer mold that has an inner diameter larger than the belt size and has irregularities for forming the tooth profile on the inner peripheral surface. The method for manufacturing a double-sided toothed belt according to claim 1, wherein a belt sleeve having an inner tooth portion is inserted into the outer mold and the outer tooth portion is formed by the outer mold.

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