JP2007216394A - Manufacturing method of toothed belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent tooth shape molding failure based on the positional shift of canvas at the time of spinning of a core wire in a manufacturing method of a toothed belt. <P>SOLUTION: In the manufacturing method of the toothed belt provided with tooth parts and groove parts and having the canvas 1 bonded to its surface, first, the mutual end parts of the canvas 1 are sewn by a sewing machine to form a joint part 4 to form the canvas 1 into a cylindrical shape. Next, an insertion rod 10 is inserted in the joint part 4 and the cylindrical canvas 1 is mounted on a mold 11 to cover the mold 11. At this time, the insertion rod 10 is positioned with respect to the mold 11 so that the joint part 4 is positioned at one of mold groove parts 12a. Subsequently, the canvas 1 is pushed in the mold groove parts 12a by a shaping roll 51 equipped with shaping teeth 57 and the core wire 21 is further spirally wound around the canvas 1 from the outside. Thereafter, an unvulcanized rubber sheet is laminated on the canvas 1 from the outside of the core wire 21 and the whole is vulcanized and molded to form a belt sleeve and this belt sleeve is cut to obtained the toothed belt. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toothed belt comprising tooth portions and groove portions alternately arranged along the longitudinal direction, a back portion in which a core wire is disposed, and a reinforcing cloth adhered to the surfaces of the tooth portions and the groove portion. It relates to a manufacturing method.

  For example, Patent Document 1 discloses a method for manufacturing a toothed belt of this type. In the method for manufacturing a toothed belt disclosed in Patent Document 1, first, a locking rod is provided at both ends of a rubber elastic stretchable canvas (reinforcing fabric) having a predetermined width and length, and the sewing thread includes the locking bar. And endlessly jointed to form a cylindrical canvas with a locking bar. Next, the cylindrical canvas with the locking rod is inserted into the outer peripheral surface of the cylindrical toothed mold having a predetermined dimension, and the locking rod is arranged and fixed along the bottom of the mold tooth groove. Subsequently, a low-stretch, high-strength tensile rope (core wire) is wound around the spiral with a constant tension on the canvas wound around the outer peripheral surface of the mold. Further, the locking rod is removed from the joint portion, and an unvulcanized rubber sheet having a predetermined thickness is laminated and wound endlessly on the tensile rope. Then, a cylindrical rubber jacket is inserted on the outer peripheral surface, and the unvulcanized rubber sheet is caused to flow from between the tension ropes by applying pressure and heating from the outside, and the rubber stretchable canvas is stretched while not extending into the mold groove. A molded body (sleeve) is formed by filling and vulcanizing the vulcanized rubber. Next, the obtained sleeve is removed from the mold and cut into a predetermined width to obtain a toothed belt having a canvas joint on the upper surface of the tooth profile.

By this method, the joint portion of the canvas can be accurately positioned on the upper surface of the convex portion of the belt tooth by the locking rod, and the life of the belt can be extended.
Japanese Patent Publication No. 3-18821 (Claim 1, column of action, drawings, etc.)

Patent Document 2 discloses that it is effective to reduce the coefficient of friction of the tooth cloth surface in order to improve the tooth chip resistance of the toothed belt coated with the tooth cloth (reinforcing cloth). ing. Patent Document 2 further discloses a configuration in which a powder-like antifriction material containing fluororesin powder is focused between the front and back surfaces of a fiber fabric and between the fibers as one method for reducing the friction coefficient. According to this, the friction coefficient reduction effect can be reliably exhibited by increasing the chance that the fluororesin powder contained in a large amount is exposed to the friction surface.
Japanese Patent No. 3347095 (0008, FIG. 1 etc.)

  However, in the manufacturing method disclosed in Patent Document 1, in the spinning process in which the core wire is wound around the canvas fixed on the mold, the canvas may be displaced due to the core wire tension during spinning. In particular, when a canvas having a low friction coefficient specification such as that of Patent Document 2 is used, there is a high possibility that the canvas slides with respect to the mold and is displaced.

  On the other hand, in the joint portion, the canvas is restrained with respect to the mold by the locking rod. For this reason, extra tension is applied to the canvas between the position shift portion and the joint portion, and the tooth portion in the vicinity of the joint portion may not be accurately formed in the subsequent vulcanization molding process. Therefore, a tooth profile defect has occurred, causing problems such as abnormal noise.

  The present invention has been made in view of the above circumstances, and an object thereof is to manufacture a toothed belt that can prevent excessive tension from being applied to the reinforcing cloth during spinning of the core wire and can accurately form a tooth profile. There is to improve the method.

Means and effects for solving the problems

  The problems to be solved by the present invention are as described above. Next, means for solving the problems and the effects thereof will be described.

  According to the 1st viewpoint of this invention, the tooth part and groove part which are arrange | positioned alternately along a longitudinal direction, the back part which has arrange | positioned the core wire, and the reinforcement cloth stuck on the surface of the said tooth part and groove part, The following manufacturing method of a toothed belt provided with these is provided. That is, a step of attaching the endless reinforcing fabric to a mold having a shape corresponding to the tooth portion and the groove portion, a typing step of pushing the reinforcing fabric into the mold groove portion by a molding roll having a shaping tooth, and the reinforcing fabric A spinning step of spinning the core wire from outside, a step of laminating an unvulcanized rubber sheet from the outside of the core wire, a step of vulcanizing and molding the unvulcanized rubber sheet to produce a belt sleeve, including.

  In this way, by shaping the reinforcing cloth into a corrugated shape in the shaping process before the spinning process, the tension of the reinforcing cloth can be prevented from increasing even if the reinforcing cloth is displaced in the spinning process. During the formation, unvulcanized rubber can flow smoothly to form teeth with an accurate shape. As a result, a toothed belt with good quality can be manufactured.

  According to the 2nd viewpoint of this invention, the manufacturing method of the following toothed belts is provided. That is, a step of sewing the end portions of the reinforcing cloth together to form a joint portion and making it endless, and a step of inserting an insertion rod inside the joint portion and outside the reinforcing fabric Attaching the reinforcing cloth to a mold having a shape corresponding to the tooth part and the groove part, attaching the insertion rod to the mold so that the joint part is located in the mold groove part, and forming with a shaping tooth A step of pressing the reinforcing cloth into the mold groove by a roll; a spinning process of spinning the core wire from the outside of the reinforcing cloth; a step of laminating an unvulcanized rubber sheet from the outside of the core wire; Vulcanizing and molding a vulcanized rubber sheet to produce a belt sleeve.

  Thus, by reinforcing the reinforcing cloth into a corrugated shape in the molding process before the spinning process, the tension of the reinforcing cloth (especially the tension of the reinforcing cloth in the vicinity of the joint portion) is reduced even if the reinforcing cloth is displaced in the spinning process. It can be prevented from increasing, and the unvulcanized rubber can be smoothly flowed in when the tooth profile is formed by vulcanization molding to form a tooth having an accurate shape. As a result, a toothed belt with good quality can be manufactured.

  According to the 3rd viewpoint of this invention, the manufacturing method of the following toothed belts is provided. That is, a step of attaching the endless reinforcing cloth to a mold having a shape corresponding to the tooth part and the groove part, and a thickness corresponding to the volume of the mold groove part or a volume lower than the outer part of the reinforcing cloth. A step of laminating the first unvulcanized rubber sheet, a molding step of pushing the reinforcing cloth and the first unvulcanized rubber sheet into a mold groove by a molding roll having a molding tooth, and a step of forming the first unvulcanized rubber sheet. A spinning step of spinning the core wire from the outside, a step of laminating the second unvulcanized rubber sheet from the outside of the core wire, and the first unvulcanized rubber sheet and the second unvulcanized rubber sheet are integrated. And vulcanizing and forming a belt sleeve.

  In this way, by shaping the reinforcing cloth into a corrugated shape in the shaping process before the spinning process, the tension of the reinforcing cloth can be prevented from increasing even if the reinforcing cloth is displaced in the spinning process. Shaped teeth can be formed. As a result, a toothed belt with good quality can be manufactured.

  According to the 4th viewpoint of this invention, the manufacturing method of the following toothed belts is provided. That is, a step of sewing the end portions of the reinforcing cloth together to form a joint portion and making it endless, and a step of inserting an insertion rod inside the joint portion and outside the reinforcing fabric Attaching the reinforcing cloth to a mold having a shape corresponding to the tooth part and the groove part, and attaching the insertion rod to the mold so that the joint part is located in the mold groove part, and an outer side of the reinforcing cloth. The reinforcing cloth and the first unvulcanized rubber sheet by a step of laminating a first unvulcanized rubber sheet having a thickness corresponding to the volume of the mold groove or a volume below the mold groove, and a molding roll having a molding tooth. A molding step of pushing into the mold groove, a spinning step of spinning the core wire from the outside of the first unvulcanized rubber sheet, and a second unvulcanized rubber from the outside of the core wire. And a step of laminating a sheet, and a step of fabricating a belt sleeve by vulcanizing molding integrally the first unvulcanized rubber sheet and the second unvulcanized rubber sheet.

  Thus, by reinforcing the reinforcing cloth into a corrugated shape in the molding process before the spinning process, the tension of the reinforcing cloth (especially the tension of the reinforcing cloth in the vicinity of the joint portion) is reduced even if the reinforcing cloth is displaced in the spinning process. It is possible to prevent the teeth from increasing, and teeth having an accurate shape can be formed during vulcanization molding. As a result, a toothed belt with good quality can be manufactured.

  In the method for manufacturing the toothed belt, it is preferable that at least a surface of the reinforcing cloth facing the mold has a powder-like antifriction material. Moreover, it is preferable that the said powder-form antifriction material is a fluororesin powder.

  Or it can also comprise so that it may have a fluorine-type fiber in the surface of the side facing the said mold of the said reinforcement cloth at least.

  That is, the above manufacturing method is particularly suitable when a reinforcing cloth subjected to anti-friction processing is used, that is, when the positional deviation of the reinforcing cloth with respect to the mold is likely to occur.

  In the manufacturing method of the above-mentioned toothed belt, it is preferable to do as follows. That is, the spinning process is performed while the core wire is wound around a touch roll that rotates independently of the mold roll. The mold forming process and the spinning process are performed in parallel by feeding the mold application roll and the touch roll in the axial direction while rotating the mold.

  Thereby, since two processes, a shaping | molding process and a spinning process, can be performed in a short time, the manufacturing cost of a toothed belt can be reduced.

  In the manufacturing method of the toothed belt, it is preferable that the shaping roll and the touch roll are arranged concentrically.

  Thereby, a shaping | molding process and a spinning process can be performed with a simple apparatus.

  In the manufacturing method of the toothed belt, it is preferable that the tip side of the shaping tooth is formed in an arc shape.

  Thereby, since a reinforcement cloth can be shape | molded in circular arc shape, a tooth profile can be shape | molded smoothly at a vulcanization molding process.

  Next, embodiments of the invention will be described. FIG. 1 is a perspective view showing an overall configuration of a toothed belt according to an embodiment of the present invention, FIG. 2 is a perspective view showing a state of a canvas in which end portions are connected to form a joint portion, and FIG. It is a cross-sectional enlarged view of canvas. FIG. 4 is a perspective view showing a state where the insertion rod is inserted into the joint portion, and FIG. 5 is an enlarged sectional view of the joint portion. FIG. 6 is a plan view showing how the canvas is attached to the mold, and FIG. 7 is a perspective view showing a through hole formed in the flange portion of the mold for attaching the insertion rod. FIG. 8 is a perspective view showing a molding process and a spinning process, FIG. 9 is a cross-sectional view showing the molding roll and the spinning roll, and FIG. 10 is an explanatory view showing a state in which the canvas is pushed into the mold groove by the molding roll. FIG. 11 is a cross-sectional view showing a state in which an unvulcanized rubber sheet is wound from the outside of the core and covered with a jacket.

  FIG. 1 shows a perspective view of a toothed belt manufactured by the method of this embodiment. The toothed belt 20 has a configuration in which a plurality of tooth portions 22 and groove portions 23 are alternately arranged at predetermined equal intervals along the longitudinal direction. A back portion 24 is continuous with the tooth portion 22, and a core wire 21 is embedded in the back portion 24. A canvas (reinforcing cloth) 1 is provided so as to cover the surfaces of the tooth portion 22 and the groove portion 23.

  The said back part 24 and the tooth | gear part 22 comprise the belt main body, and this belt main body is formed with the rubber compound. The canvas 1 is composed of a fiber fabric formed by weaving weft yarns 2 extending in the longitudinal direction of the belt and warp yarns 3 extending in the width direction.

  FIG. 2 shows a perspective view of the cylindrical canvas 1 used when the toothed belt 20 is manufactured. The canvas 1 can employ any one of nylon, aramid, polyester, polyenoxazole, cotton, or a combination thereof. The form of the fibers constituting the weft 2 and the warp 3 may be either a filament yarn or a spun yarn, and may be any one of a single composition twisted yarn, a mixed twisted yarn, or a mixed spun yarn. In addition, the woven structure of the canvas 1 can be appropriately selected from plain woven fabric, twill woven fabric, satin woven fabric, and the like.

  And the textile fabric which comprises the said canvas 1 impregnates the 1st process liquid which added and disperse | distributed at least fluororesin powder to the resorcin-formalin-rubber latex (RFL) process liquid, Then, between a pair of pressure rolls To adjust the amount of adhesion. Then, it heat-drys at 150 to 200 degreeC for 1 minute-3 minutes.

  In the canvas 1 thus obtained, as shown in FIG. 3 as an enlarged cross-sectional view, a fluororesin powder (powder antifriction material) is provided between the front and back surfaces of the fiber fabric formed by weaving the weft 2 and the warp 3 and the fiber. ) 63 is impregnated with a mixture 64 of the rubber component 61 and the resin-based adhesive component 62 so that the particles 63 converge.

  The rubber component 61 is a rubber solid obtained by treating and drying a rubber latex, and the resin adhesive component is an initial condensate of resorcin and formalin. The rubber component 61 and the resin-based adhesive component 62 are solid contents remaining after the RFL treatment liquid is dried and heated.

  The resin adhesive component 62 is bonded to the fibers of the weft 2 and the warp 3. Further, a fluororesin powder 63 is dispersed and mixed in a matrix composed of the rubber component 61 and the resin adhesive component 62. The fluororesin powder 63 is not bonded to the rubber component 61 and the resin adhesive component 62.

  The RFL treatment liquid is a mixture of resorcin and formalin initial condensate and rubber latex. In this case, the molar ratio of resorcin and formalin is 3/1 to 1/3 in order to increase the adhesive strength. Is preferred. The initial condensate of resorcin and formalin is mixed with rubber latex so that the resin content is 5 to 50 parts by mass with respect to 100 parts by mass of the rubber component of the rubber latex, and further contains all fluororesin powder. The solid concentration is adjusted to a concentration of 10% to 40%.

  Examples of the rubber latex that forms the rubber component 61 include styrene-butadiene-vinylpyridine terpolymer (VP), styrene butadiene copolymer (SBR), chloroprene (CR), acrylonitrile butadiene copolymer (NBR), hydrogen. One kind or a blend of two or more kinds of added NBR (H-NBR), chlorosulfonated polyethylene (CSM), natural rubber and the like is used.

  The fluororesin powder 63 that does not bind to the rubber component 61 or the resin-based adhesive component 62 is polytetrafluoroethylene, polytrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, tetrafluoroethylene-perfluoroalkoxyethylene. It is one or more of a copolymer and a tetrafluoroethylene-ethylene copolymer. The greater the ratio of the number of fluorine atoms in the fluororesin powder 63, the greater the friction coefficient reducing effect. Therefore, assuming the same amount of adhesion to the fiber fabric, among the fluororesin powder 63, polytetrafluoroethylene has the largest effect of reducing the friction coefficient and has a long tooth-breaking life. However, other fluororesins are also effective in proportion to the proportion of the number of fluorine atoms in the molecule.

  Such a fluororesin powder 63 is added to 30 to 200 parts by mass (more preferably 50 to 200 parts by mass) with respect to 100 parts by mass of the rubber component in the RFL treatment liquid to obtain a uniformly dispersed treatment liquid. There is a need. Also, the fiber fabric is dipped in the treatment liquid and dried, and adjusted so that the solid mixture 64 containing the fluororesin powder 63 has an adhesion amount of 5% to 40% with respect to the weight of the fiber fabric before immersion. Is preferred. When the fluororesin powder is less than 30 parts by mass or less than 5%, the total amount of the fluororesin powder entangled with the fiber fabric is small, and the effect of reducing the friction coefficient is hardly recognized. On the other hand, when the fluororesin powder exceeds 300 parts by mass or exceeds 40%, the total amount of the fluororesin powder entangled with the fiber fabric is too large, and the adhesion of the fiber fabric to the belt main body or the like decreases, resulting in a decrease in belt performance. Come.

  In addition, powder-type anti-friction materials other than fluororesin powder that can be used simultaneously include layered graphite, molybdenum disulfide, glass beads, ceramic powder, spherical phenol resin powder and aramid, polyamide, polyester, polybenzoxazole, fiber One or more types of cut yarn or powder can be exemplified. In particular, graphite is familiar with the rubber component and further improves the durability of the belt. The powder-like antifriction material is 30 to 200 parts by mass with respect to 100 parts by mass of the rubber component in the RFL treatment liquid, and it is preferable to increase the amount of the fluororesin powder added. However, the mixing ratio of the fluororesin powder and the powdered antifriction material is not particularly limited.

  In addition, what is necessary is just to use the following methods, when measuring the adhesion amount to the textile fabric of the said mixture. That is, the mass of the fiber fabric before the immersion treatment is weighed and the mass (W1) is measured, and then the fiber fabric is immersed in the RFL treatment liquid in which the fluororesin powder is dispersed, and then the fiber fabric is placed in an oven to keep the mass constant. Drying is continued until the final mass (W2) is measured, and the adhesion amount is calculated according to the formula ((W2-W1) / W1) × 100 (%).

  In order to entangle a large amount of fluororesin powder 63 to the inside of the fiber fabric, it is pulverized or granulated and its average particle diameter is 100 μm or less (more preferably 10 μm or less). Is used. If the particle diameter exceeds 100 μm, the fluororesin powder settles in the RFL treatment liquid and becomes difficult to disperse uniformly, and the surface area of the fluororesin powder in the mixture is further reduced, reducing the friction coefficient reducing effect. . From such a viewpoint, the fluororesin powder preferably has a particle size as small as possible, for example, 10 μm or less.

  A rubber paste can be further adhered to the fiber fabric subjected to the adhesion treatment of the fluororesin powder. In the example of FIG. 3, the rubber compound of the same kind as the isocyanate compound and the belt main body is dissolved and mixed in a solvent such as methyl ethyl ketone (MEK) and toluene to form a first rubber paste. After the first rubber paste is impregnated with the fiber fabric, the amount of the first rubber paste is adjusted between a pair of pressure rolls. Thereafter, the first rubber layer 7 is formed by heating and drying at 150 to 180 ° C. for 1 to 3 minutes.

  The isocyanate compound used here is to improve the adhesive force between the fiber woven fabric with the fluororesin powder adhered thereto and the belt body. Specific examples thereof include 4,4′-diphenylmethane diisocyanate and tolylene 2,4. -Diisocyanate, polymethylene polyphenyl diisocyanate, hexamethylene diisocyanate, polyaryl polyisocyanate (for example, PAPI under the trade name) and the like. This isocyanate compound is also used by mixing with an organic solvent such as toluene or methyl ethyl ketone. In addition, blocked polyisocyanates in which the isocyanate group of the polyisocyanate is blocked by reacting the isocyanate compound with a blocking agent such as phenols, tertiary alcohols, and secondary alcohols can also be used.

  Examples of the epoxy compound include polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, reaction products of polyalkylene glycols such as polyethylene glycol and halogen-containing epoxy compounds such as epichlorohydrin, resorcin, bis (4 -Hydroxyphenyl) dimethylmethane, reaction products with polyhydric phenols such as phenol / formaldehyde resin, resorcin / formaldehyde resin, and halogen-containing epoxy compounds. The epoxy compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone.

  Further, in the configuration of FIG. 3, the second rubber paste is adhered. Specifically, a fluororesin powder or an antifriction material other than the above-mentioned fluororesin powder is blended in the same rubber compound as that of the belt body, dissolved in a solvent such as methyl ethyl ketone (MEK), toluene, etc., and mixed. Use rubber glue. Then, after the fiber fabric on which the first rubber layer 7 is formed is impregnated and adhered to the second rubber paste, the amount of the second rubber paste is adjusted between a pair of pressure rolls. Thereafter, the outermost second rubber layer (outermost rubber layer) 8 is adhered by heating and drying at 80 to 150 ° C. for 1 to 3 minutes. In this case, the addition amount of the fluororesin powder or the antifriction material other than the fluororesin powder is preferably 50 to 400 parts by mass with respect to 100 parts by mass of the rubber component of the rubber compound. As a result, the second rubber layer 8 of the canvas 1 is provided with an antifriction material such as fluororesin powder.

  And as shown in FIG. 2, the both ends of the canvas 1 are joined by the joint part 4, and are comprised in endless form (cylindrical shape). The joint portion 4 is obtained by stitching the ends of the canvas 1 together with a sewing thread 6 made of polyamide yarn such as 6 nylon, 6, 6 nylon, 12 nylon, etc., polyester twisted yarn such as polyester, polypropylene, aramid, or monofilament yarn.

  In addition, as shown in FIG. 6, this canvas 1 is used by covering it with a cylindrical mold 11 for forming the toothed belt 20. On the outer peripheral surface (mold surface) of the mold 11, elongated mold groove portions 12 a having a shape corresponding to the tooth portions 22 of the toothed belt 20 and elongated mold crest portions 12 b having a shape corresponding to the groove portions 23 are alternately arranged. Prepared at intervals.

  The strength of the sewing machine of the joint part 4 shown in FIG. 2 is measured by a resistance value for pushing the insertion rod between the sewing thread of the sewing machine seam and the canvas, and usually this measured value is in the range of 1 to 5 kg. Set as follows.

  In this measuring method, a sewing sewing strength measuring jig (not shown) in which an insertion rod having a length of 200 mm to 500 mm and a diameter of 1 mm to 3 mm, such as stainless steel whose tip is in a needle state, is attached to a tension gauge by welding or the like. ) To measure the mechanical resistance at the time of insertion. Specifically, the jig is inserted about 100 mm to 400 mm between the sewing thread on the outer side of the cylindrical canvas and the canvas, and the maximum mechanical resistance value, which is an indentation pressure, is quantitatively measured with a tension gauge. To do. When the strength of the sewing machine is small, the mechanical resistance value is small. Conversely, when the strength of the sewing machine is large, the mechanical resistance value is large.

  In the present embodiment, when the sewing machine is weak and the mechanical resistance value is less than 1 kg, the sewing thread is stretched, and unvulcanized rubber may overflow from the joint portion 4 in the vulcanization molding process described later. Absent. On the other hand, when the sewing machine is strong and the resistance value exceeds 5 kg, the joint portion 4 is pushed up. When this is used, the raised portion of the joint portion 4 is buried inside the tooth portion 22 and the use is started. Even at an early stage later, cracks are likely to occur from this portion, resulting in cracking during belt running.

  4 and 5 show a state in which the insertion rod 10 is inserted into the joint portion 4. Specifically, the insertion rod 10 is inserted into the joint portion 4 at a position outside the canvas 1. That is, the insertion rod 10 is inserted between the sewing thread 6 and the canvas 1 located on the outer side of the cylindrical canvas 1. In the present embodiment, the insertion rod 10 is made of a rigid metal or synthetic resin, has a sharp tip, and has a circular or elliptical cross section, for example. As the insertion rod 10, for example, an elongated wire can be adopted. The insertion bar 10 has a length that spans the entire width of the canvas 1.

  In this embodiment, the insertion rod 10 has a thickness (cross-sectional area) that can sufficiently enter the inside of the mold groove 12a (FIG. 6), but the cross-sectional area is usually the volume of the mold groove 12a. Preferably it is less than 30%. When it is 30% or more, the insertion rod 10 is difficult to be pulled out from the joint portion 4, and the sewing thread 6 is stretched, so that the joint portion 4 is likely to be deformed or cut.

  FIG. 6 shows a state in which the cylindrical canvas 1 with the insertion rod 10 inserted is put on the mold 11. As shown in FIG. 6 and FIG. 7 as an enlarged perspective view of the mold 11, a flange portion 13 is provided at one axial end of the mold 11, and a through hole 15 is formed in the flange portion 13. . The through hole 15 is disposed at a position corresponding to the center of the mold groove 12a. For this reason, by inserting the end portion of the insertion rod 10 into the through hole 15, the insertion rod 10 (and thus the joint portion 4) can be accurately positioned at the center position in the mold groove portion 12a.

  Next, the cylindrical canvas 1 is pressed into the mold groove portion 12a and molded, and the core wire 21 as a tensile body is wound in a spiral shape.

  Although the said core wire 21 is not specifically limited, Generally a glass core wire and an aramid core wire are used. Further, any twisted cord composed of polybenzoxazole, polyparaphenylene naphthalate, polyester, acrylic, carbon, and steel can be used. The composition of the glass core wire may be either E glass or S glass (high strength glass), and does not limit the thickness of the filament, the number of converged filaments and the number of strands. Further, the sizing agent, RFL, overcoat agent and the like used as an adhesive treatment agent and a glass filament protective material at the time of bending are not limited. On the other hand, the aramid core wire is not limited by the difference in the molecular structure of the material, the configuration of the core wire, the size of the filament, or the difference in the adhesive treatment agent. Similarly, there is no particular limitation on the twisted cords of the cords made of other compositions.

  In the present embodiment, the above-described molding process and spinning process are performed using a molding spinning apparatus 50 that includes a molding roll 51 and a touch roll 52 side by side, as shown in FIGS. The mold spinning apparatus 50 includes an electric motor (not shown) that rotationally drives the mold 11 on which the canvas 1 is mounted, the mold roll 51 and the touch roll 52 disposed near the outer peripheral surface of the mold 11, and the mold roll 51 and the touch. An unillustrated feeding device for feeding the roll 52 along the mold axis direction.

  As shown in FIG. 9 and the like, the mold spinning device 50 includes a support bracket 53, and a support shaft 54 disposed horizontally is fixed to the support bracket 53 in a cantilever manner. The touch roll 52 is rotatably supported by the support shaft 54 via a bearing 55, and the shaping roll 51 is rotatably supported by a bearing 56.

  The molding roll 51 and the touch roll 52 are arranged concentrically while being adjacent to each other, and are rotatable independently of each other. A plurality of shaping teeth 57 are formed at equal intervals on the outer periphery of the shaping roll 51. Each of the shaping teeth 57 is formed in a semicircular shape, and the tip side is formed in an arc shape. With this configuration, as shown in FIGS. 8 and 10, by rotating the mold 11 in a state where the mold teeth 57 and the mold groove 12a are engaged, the mold roll 51 is also driven to rotate, and the mold teeth 57 are moved to the canvas. 1 is pushed into the mold groove 12a. As a result, the canvas 1 is waved.

  Further, the core wire 21 is wound around the outer peripheral surface of the touch roll 52, contacts with the outer peripheral surface of the canvas 1, and is rotated following the rotation of the mold 11. As a result, the core wire 21 can be wound around the outer peripheral surface of the canvas 1 while applying an appropriate tension.

  At the same time as the mold 11 is driven to rotate, the mold roll 51 and the touch roll 52 are fed at a constant speed in the direction along the support shaft 54 (direction A in FIG. 8). Accordingly, the canvas 1 is gradually molded by the mold roll 51 from one end in the width direction of the canvas 1 toward the other end. The core wire 21 is spirally wound at a predetermined pitch from the one end in the width direction to the other end by the touch roll 52.

  Further, a mold roll 51 is disposed on the leading side in the feeding direction (A direction), and the touch roll 52 is disposed immediately on the subsequent side. Accordingly, the canvas 1 is first molded by the molding roll 51 from one end to the other in the width direction, and then the core wire 21 is wound around the outside of the canvas 1. Thus, in this embodiment, the molding process and the spinning process are performed in parallel.

  Here, as described above, the canvas 1 according to the present embodiment is subjected to the anti-friction treatment on the surface. Therefore, even when the canvas 1 is attached to the mold 11, the canvas 1 is easy to slide with respect to the mold 11. Therefore, generally, when winding the core wire 21 in the spinning process, the canvas 1 is likely to be displaced in the circumferential direction with respect to the mold 11 due to the tension of the core wire 21. On the other hand, since the joint portion 4 is positioned on the mold 11 via the insertion rod 10, a strong tension is generated in the canvas 1 particularly in a portion located near the joint portion 4 with the positional deviation of the canvas 1. easy. The excessive tension of the canvas 1 hinders the flow of unvulcanized rubber into the mold groove 12a in the subsequent vulcanization process, causing a tooth profile defect.

  In this regard, in the present embodiment, before the spinning process, a molding process (FIG. 10) is performed in which the canvas 1 is pushed into the mold groove portion 12a to form a waveform. Therefore, even if the above-described positional deviation occurs in the canvas 1 in the subsequent spinning process, the deviation is absorbed by the corrugated portion, and the tension of the canvas 1 hardly increases.

  Subsequently, as shown in FIG. 11, an unvulcanized rubber sheet 25 forming the tooth portion 22 and the back portion 24 is laminated from the outside of the core wire 21, and then the insertion rod 10 is pulled out from the joint portion 4. FIG. 11 shows a state in which the insertion rod 10 has been removed.

  Examples of the unvulcanized rubber sheet 25 include hydrogenated nitrile rubber, hydrogenated nitrile rubber added with a metal salt of unsaturated carboxylic acid, chlorosulfonated polyethylene (CSM), alkylated chlorosulfonated polyethylene ( ACSM) and rubbers with improved heat aging resistance such as chloroprene rubber are preferred. The hydrogenated nitrile rubber has a hydrogenation rate of 80% or more, and 90% or more is preferable for exhibiting heat resistance and ozone resistance. Hydrogenated nitrile rubber having a hydrogenation rate of less than 80% is extremely deteriorated in heat resistance and ozone resistance.

  And this is covered with a jacket 26 and placed in a vulcanizing can for vulcanization. In this vulcanization molding step, the unvulcanized rubber sheet 25 is pressurized and heated from the outside through the jacket 26, and thus exhibits a fluid state and flows into the mold groove 12a through the gap between the core wires 21, A tooth portion 22 is formed. In this way, a belt sleeve can be produced.

  As described above, since the canvas 1 is wave-shaped over the entire circumference of the mold 11 before vulcanization molding as shown in FIG. 10 and the like, the tension of the canvas 1 is not excessive in the vulcanization molding process. The unvulcanized rubber spreads the canvas 1 smoothly and adheres to the surface of each mold groove 12a. That is, since the tension of the canvas 1 hardly inhibits the flow of the unvulcanized rubber, the molding of the tooth portion 22 by the mold groove portion 12a is surely performed, and the belt sleeve having good shape (as a result, the toothed belt 20). ) Can be obtained.

  Further, since the joint portion of the canvas 1 is positioned at the center position of the mold groove portion 12a by the insertion rod 10 until the pre-vulcanization molding stage, the joint portion 4 is reliably positioned at the center of the tooth portion 22 during the vulcanization molding. (See FIG. 1). As a result, it is possible to prevent the tooth portion 22 from being worn or cracked and to extend the life of the toothed belt 20.

  The vulcanized belt sleeve is extracted from the mold 11 and attached to two shafts of a cutting machine (not shown). And the toothed belt 20 shown in FIG. 1 is producible by cut | disconnecting to predetermined width with a cutter, giving tension in a cutting machine and rotating.

  As described above, the toothed belt 20 of the present embodiment includes the tooth portions 22 and the groove portions 23 that are alternately arranged along the longitudinal direction, the back portion 24 on which the core wire 21 is disposed, and the tooth portions 22 and the groove portions. 23, and a canvas 1 attached to the surface of 23. The toothed belt 20 includes a step of attaching the cylindrical canvas 1 to a mold 11 having a shape corresponding to the tooth portion 22 and the groove portion 23 (FIG. 6), and the canvas 1 Is pushed into the mold groove 12a and the core wire 21 is spun (FIG. 8), the unvulcanized rubber sheet 25 is laminated thereon (FIG. 11), and the unvulcanized rubber sheet 25 is vulcanized. And manufacturing a belt sleeve.

  More specifically, the toothed belt 20 includes a step (FIG. 2) in which the end portions of the canvas 1 are sewn together to form the joint portion 4 to form an endless shape (FIG. 2), and the inside of the joint portion 4. The insertion rod 10 is inserted into a position outside the canvas 1 (FIG. 4), the canvas 1 is attached to the mold 11, and the joint rod 4 is positioned in the mold groove 12a. 10 is attached to the mold 11 (FIG. 6), a mold-setting step (FIGS. 8 and 10) is performed by pressing the canvas 1 into the mold groove portion 12a by a mold roller 51 including the mold teeth 57, and a core is formed from the outside of the canvas 1. A spinning step (FIG. 8) for spinning the wire 21; a step of laminating the unvulcanized rubber sheet 25 from the outside of the core wire 21; Are produced by a method comprising the steps of preparing a chromatography blanking, the.

  In this way, by shaping the canvas 1 into a waveform in the shaping process before the spinning process, even if the canvas 1 is displaced from the mold 11 in the spinning process, the tension of the canvas 1 (particularly the joint portion). (Tension of the canvas 1 near 4) can be prevented from increasing. Thereby, when the tooth profile is formed by vulcanization molding, the unvulcanized rubber can be smoothly flown to form the tooth portion 22 having an accurate shape, and the toothed belt 20 with good quality can be manufactured.

  Further, the toothed belt 20 of the present embodiment has a fluororesin powder (powder antifriction material) on at least the surface of the canvas 1 facing the mold 11. In the case of the canvas 1 subjected to the anti-friction process in this manner, positional displacement with respect to the mold 11 in the spinning process is likely to occur. However, according to the present embodiment that can suppress an increase in the tension of the canvas 1, the tooth having an accurate shape is used. The portion 22 can be formed.

  Further, in the spinning process of this embodiment, the core wire 21 is wound around the touch roll 52 that rotates independently of the mold roll 51. And it is comprised so that the said shaping | molding process and the said spinning process may be performed in parallel by sending the said shaping | molding roll 51 and the touch roll 52 to an axial direction, rotating the said mold 11. FIG. As a result, the molding step and the spinning step can be performed in a short time, and the manufacturing cost can be reduced. Further, since the molding roll 51 rotates independently of the touch roll 52, the rotation of the touch roll 52 does not affect the rotation of the molding roll 51, and the canvas 1 can be molded smoothly and reliably.

  Furthermore, in the manufacturing method of this embodiment, the said shaping | molding roll 51 and the said touch roll 52 are arrange | positioned concentrically. Therefore, a simple configuration of the molding spinning device 50 is realized.

  The tip side of the shaping tooth 57 is formed in an arc shape. Therefore, it is possible to smoothly perform the molding without damaging the canvas 1 in the molding process. Furthermore, since the canvas 1 can be molded into an arcuate waveform, the tooth portion 22 can be smoothly molded by the flow of unvulcanized rubber in the vulcanization molding process.

  In addition, after attaching the canvas 1 to the mold 11, an unvulcanized rubber sheet may be wound around the canvas 1 before the molding step and the spinning step. The unvulcanized rubber sheet (first unvulcanized rubber sheet) wound at this time preferably has a thickness equal to or smaller than the volume of the mold groove 12a. In the molding process and the spinning process, the canvas 1 and the first unvulcanized rubber sheet are stacked in a wave shape with the molding teeth 57 of the molding roll 51, and further the core wire 21 is wound thereon. Become. Thereafter, an unvulcanized rubber sheet (second unvulcanized rubber sheet) 25 is wound from the outside, and the two unvulcanized rubber sheets are integrally vulcanized and molded. Even in this case, the toothed belt 20 having a good tooth shape can be manufactured.

  Further, on the surface of the canvas 1 facing the mold 11 side (inner peripheral surface of the cylindrical canvas 1), in addition to or instead of the powdered antifriction material, fluorine-based fibers (having a low friction coefficient and wear resistance). (Good fiber) may be provided.

  Although the preferred embodiment and the modification of the present invention have been described above, the above configuration is an example, and can be modified as follows, for example.

  The molding roll 51 and the touch roll 52 are not limited to being concentrically arranged adjacent to each other, and can be changed to a configuration in which the molding roll 51 and the touch roll 52 are installed on two support brackets that are arranged independently, for example. .

  Moreover, the manufacturing method of the toothed belt of the present invention can be similarly applied even when the canvas 1 is not subjected to the anti-friction treatment.

The perspective view which showed the whole structure of the toothed belt which concerns on one Embodiment of this invention. The perspective view which shows the mode of the canvas which connected the edge parts and formed the joint part. The cross-sectional enlarged view of canvas. The perspective view which shows a mode that the insertion stick | rod was inserted in the joint part. The expanded sectional view of a joint part. The top view which shows a mode that a canvas is mounted | worn to a mold. The perspective view which shows the through-hole formed in the flange part of a mold in order to attach an insertion rod. The perspective view which shows a shaping | molding process and a spinning process. Sectional drawing which shows a shaping | molding roll and a spinning roll. Explanatory drawing which shows a mode that a canvas is pushed into a mold groove part with a shaping roll. Sectional drawing which shows the state which wound the unvulcanized rubber sheet from the outer side of the core wire, and covered the jacket.

Explanation of symbols

1 Canvas (reinforcing cloth)
DESCRIPTION OF SYMBOLS 4 Joint part 6 Sewing thread 10 Insertion rod 11 Mold 12a Mold groove part 15 Through-hole 20 Toothed belt 21 Core wire 22 Tooth part 23 Groove part 24 Back part 25 Unvulcanized rubber sheet 51 Molding roll 52 Touch roll 57 Modeling tooth

Claims (10)

In a manufacturing method of a toothed belt comprising: tooth portions and groove portions alternately arranged along the longitudinal direction; a back portion on which a core wire is disposed; and a reinforcing cloth adhered to the surfaces of the tooth portions and the groove portion.
Attaching the endless reinforcing fabric to a mold having a shape corresponding to the tooth and groove;
A molding step of pushing the reinforcing cloth into the mold groove by a molding roll having a molding tooth;
A spinning step of spinning the core wire from the outside of the reinforcing cloth;
Laminating an unvulcanized rubber sheet from the outside of the core wire;
A step of vulcanizing and molding the unvulcanized rubber sheet to produce a belt sleeve;
The manufacturing method of a toothed belt characterized by including. In a manufacturing method of a toothed belt comprising: tooth portions and groove portions alternately arranged along the longitudinal direction; a back portion on which a core wire is disposed; and a reinforcing cloth adhered to the surfaces of the tooth portions and the groove portion.
A step of sewing the end portions of the reinforcing cloth together to form a joint portion and making it endless;
Inserting an insertion rod inside the joint part and outside the reinforcing cloth;
Attaching the reinforcing cloth to a mold having a shape corresponding to the tooth part and the groove part, and attaching the insertion rod to the mold so that the joint part is located in the mold groove part;
A molding step of pushing the reinforcing cloth into the mold groove by a molding roll having a molding tooth;
A spinning step of spinning the core wire from the outside of the reinforcing cloth;
Laminating an unvulcanized rubber sheet from the outside of the core wire;
Vulcanizing the unvulcanized rubber sheet to produce a belt sleeve;
The manufacturing method of a toothed belt characterized by including. In a manufacturing method of a toothed belt comprising: tooth portions and groove portions alternately arranged along the longitudinal direction; a back portion on which a core wire is disposed; and a reinforcing cloth adhered to the surfaces of the tooth portions and the groove portion.
Attaching the endless reinforcing fabric to a mold having a shape corresponding to the tooth and groove;
Laminating a first unvulcanized rubber sheet having a thickness corresponding to the volume of the mold groove or a volume lower than the volume of the mold groove on the outside of the reinforcing cloth;
A molding step of pushing the reinforcing cloth and the first unvulcanized rubber sheet into a mold groove by a molding roll having a molding tooth;
A spinning step of spinning the core wire from the outside of the first unvulcanized rubber sheet;
Laminating a second unvulcanized rubber sheet from the outside of the core wire;
A step of integrally vulcanizing and molding the first unvulcanized rubber sheet and the second unvulcanized rubber sheet to produce a belt sleeve;
The manufacturing method of a toothed belt characterized by including. In a manufacturing method of a toothed belt comprising: tooth portions and groove portions alternately arranged along the longitudinal direction; a back portion on which a core wire is disposed; and a reinforcing cloth adhered to the surfaces of the tooth portions and the groove portion.
A step of sewing the end portions of the reinforcing cloth together to form a joint portion and making it endless;
Inserting an insertion rod inside the joint part and outside the reinforcing cloth;
Attaching the reinforcing cloth to a mold having a shape corresponding to the tooth part and the groove part, and attaching the insertion rod to the mold so that the joint part is located in the mold groove part;
Laminating a first unvulcanized rubber sheet having a thickness corresponding to the volume of the mold groove or a volume lower than the volume of the mold groove on the outside of the reinforcing cloth;
A molding step of pushing the reinforcing cloth and the first unvulcanized rubber sheet into a mold groove by a molding roll having a molding tooth;
A spinning step of spinning the core wire from the outside of the first unvulcanized rubber sheet;
Laminating a second unvulcanized rubber sheet from the outside of the core wire;
A step of integrally vulcanizing and molding the first unvulcanized rubber sheet and the second unvulcanized rubber sheet to produce a belt sleeve;
The manufacturing method of a toothed belt characterized by including.   The method for manufacturing a toothed belt according to any one of claims 1 to 4, wherein the reinforcing cloth has a powder-like antifriction material on at least a surface facing the mold. Manufacturing method of toothed belt.   6. The method for manufacturing a toothed belt according to claim 5, wherein the powdery antifriction material is a fluororesin powder.   The method for manufacturing a toothed belt according to any one of claims 1 to 4, wherein the reinforcing cloth has fluorine-based fibers on at least a surface facing the mold. A method for manufacturing a belt. It is a manufacturing method of the toothed belt according to any one of claims 1 to 7,
The spinning step is configured to be performed while the core wire is wound around a touch roll that rotates independently of the mold roll,
A method for manufacturing a toothed belt, wherein the mold forming step and the spinning step are performed in parallel by feeding the mold roll and the touch roll in an axial direction while rotating the mold.   The method for manufacturing a toothed belt according to claim 8, wherein the shaping roll and the touch roll are arranged concentrically. A method for producing a toothed belt according to any one of claims 1 to 9,
A manufacturing method of a toothed belt, wherein a tip side of the shaping tooth is formed in an arc shape.

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