JP2006168356A - Manufacturing method of center belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a center belt which can certainly give a concavo-convex shape to a canvas when a concavo-convex pitch is small and even when the stiffness of a canvas is high, can eliminate the cause of the difficulty of meeting to irregularity of the canvas, and can certainly form a concavo-convex shape of a center belt. <P>SOLUTION: The manufacturing method of a center belt for a high-load transmission belt consisting of blocks fixedly fitted in which a cover canvas overlies its front face comprises a process, wherein a cover canvas 25 is arranged on a mold 100 having a concavo-convex shape, the cover canvas 25 is made to meet the concavo-convex shape of the mold 100 by a pressure member 104, and vulcanization is carried out by overlying the rubber sheet 107 and adding heat and pressure after removing the pressure member 104. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is a method for manufacturing a center belt for a high load transmission belt used for applications such as a continuously variable transmission such as an automobile, a motorcycle or an agricultural machine in which blocks are arranged in the longitudinal direction on the center belt. The present invention also relates to a method of manufacturing a center belt that can reliably form the uneven shape of the center belt.

  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. Protrusions 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. A cover canvas is laminated on the surface of the center belt for reinforcement.

  A manufacturing method of such a center belt includes a cover sheet and a rubber sheet that are overlapped and pressed to produce a composite sheet provided with concavities and convexities on one side to engage with a block, and the composite sheet is formed into a cylindrical mold. Wrap it around the core wire in a spiral shape, wrap around the rubber sheet and vulcanize.

  After vulcanization, the rubber sheet is taken out from the mold, and a rubber sheet is laminated on the back side. Subsequently, a center belt having irregularities on both sides can be obtained by cutting and finishing to a predetermined width.

  The movement of the center belt and the block in the longitudinal direction of the block is controlled by the engagement by these unevennesses, and if the unevenness of the center belt is not formed as designed, it leads to loosening between the center belt and the block, There was a problem in that movement occurred between the two, leading to heat generation due to wear and friction of the center belt and the block, and finally the center belt was cut to cause failure at an early stage.

  In order to prevent wear of the center belt, it is conceivable to use high-strength fibers such as aramid fiber as the material for the cover belt of the center belt, but canvas made of aramid fiber is highly rigid and has an uneven shape on the mold. Difficult to follow. Therefore, the uneven shape of the center belt is hardly formed.

  In Patent Document 2, in a method for manufacturing a toothed belt, a suction hole is provided in a mold, and a canvas placed on the tooth surface of the toothed belt is sucked to form a tooth shape of the mold. A technique is disclosed in which a toothed belt in which the tooth profile of a belt is reliably formed can be manufactured by winding a core wire or a rubber sheet and performing vulcanization molding.

Japanese Patent Laid-Open No. 63-34342 JP 62-7532 A

  By forming a suction hole in the mold as described in Patent Document 2 and sucking the canvas, the formation of the tooth profile is greatly improved. However, when the size of each uneven shape is small or the rigidity of the canvas is high. If that is not enough.

  Therefore, in the present invention, in the belt in which the center belt and the block are engaged with each other, the uneven shape of the center belt can be surely formed, the looseness between the belt and the block is less likely to occur, and failures such as belt cutting are reduced and the life of the belt is reduced. The purpose is to provide a long high load transmission belt.

  In order to achieve the above object, in claim 1 of the present invention, a center belt in which a core is embedded in rubber, and at least one surface of the center belt has irregularities at a predetermined pitch along the longitudinal direction. And a center belt used for a high load transmission belt comprising the unevenness and a fixed block, and a center belt made of rubber having a cover canvas laminated on the surface thereof. The cover canvas is made to conform to the uneven shape of the mold by the pressing member, and after removing the pressing member, a rubber sheet is stacked and vulcanized by heating and pressurizing.

  According to a second aspect of the present invention, a suction hole is provided in at least the concave portion of the mold, and the center belt is manufactured by sucking the cover canvas pressed against the mold by the pressing member and holding the uneven shape of the cover canvas.

  According to a third aspect of the present invention, the suction hole is provided at the bottom of the concave portion of the mold, and a rubber protrusion is formed on the convex portion of the center belt by molding the center belt while sucking. 2. The manufacturing method of the center belt described in 2.

  According to a fourth aspect of the present invention, the center belt manufacturing method is configured such that suction is not performed in a suction hole in which no canvas is arranged.

  When the cover canvas provided on the surface of the center belt as in claim 1 is made to conform to the concave and convex shape of the mold with the pressing member and then the rubber is laminated and heated and pressed, Even if the canvas has a high rigidity, it is possible to make the canvas have an irregular shape, so the cause of the difficulty along the irregularity of the canvas is eliminated, so that the uneven shape of the center belt is surely formed. become.

  In the second aspect, in addition to the molding of the canvas by the pressing member in the first aspect, a suction hole is provided in the mold so that the canvas is sucked with the uneven shape and is attracted to the mold. The uneven shape is more reliably formed.

  According to a third aspect of the present invention, the suction hole is provided at the bottom of the concave portion of the mold, and a rubber protrusion is formed on the convex portion of the center belt by forming the center belt while sucking. Thus, the fitting force between the center belt and the block can be increased.

  Claim 4 employs a configuration in which suction is not performed in the suction holes in which the canvas is not yet arranged. There is a problem that if suction is performed including suction holes where no canvas is placed, air will be sucked from those suction holes, and the suction force at the suction holes where the canvas is placed must be reduced. A sufficient suction force can be secured by sucking only the place where the is disposed.

  FIG. 1 is a schematic perspective view showing an example of a high-load transmission belt 1 using a center belt manufactured by the method of the present invention, and FIG. 2 is a cross-sectional view of the center belt. A high load transmission belt 1 using a center belt manufactured by the method for manufacturing a center belt for a high load transmission belt according to the present invention has the same width formed by embedding a rope-shaped core body 5 in a spiral shape in a rubber 4. The block 2 has two center belts 3a and 3b and grooves 14 and 15 into which the center belts 3a and 3b are fitted on the side surfaces 2a and 2b.

  The center belts 3a and 3b are locked and fixed in the grooves 14 and 15 of the block 2 to the concave strips 18 and 19 formed on the upper and lower surfaces 22 and 23 of the center belt 3a and 3b at a predetermined pitch. . Both block side surfaces 2a and 2b 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 by the center belts 3a and 3b. The power of the driving pulley is transmitted to the driven pulley. Cover canvases 24 and 25 are laminated on the upper and lower surfaces of the center belts 3a and 3b.

  As shown in FIG. 1, the block 2 includes an upper beam portion 11 and a lower beam portion 12, and a center pillar 13 in which the central portions of the upper and lower beam portions 11 and 12 are connected to each other. Grooves 14 and 15 into which the center belts 3a and 3b are fitted are formed. Further, as shown in FIG. 2, the groove upper surface 16 and the groove lower surface 17 in the groove 15 are projected on the groove 18 provided on the upper surface 22 of the center belt 3 and on the groove 19 provided on the lower surface 23. Portions 20 and 21 are provided, whereby the block 2 and the center belts 3a and 3b are locked and fixed. Concave portions 19 are formed at a predetermined pitch on the lower surface 23 of the center belt, and of course there are convex portions 26 between them.

  As shown in FIG. 2, the center belts 3a and 3b have a core 5 embedded in the center of the center belt in the thickness direction, and are composed of an inner layer 4a located on the inner circumference side and an outer layer 4b located on the outer circumference side. It has become.

  In the present invention, as a method of manufacturing such a center belt, first, as shown in FIG. 3, the convex strips 101a, 101b, 101c, and 101d that form the concave strip 19 and the convex strip 26 on the lower surface 23 of the center belt, The cover canvas 25 is disposed on the mold 100 in which the concave portions 102a, 102b, 102c, and 102d are alternately disposed. Next, the cover canvas 25 is pressed against the concave strips 102a, 102b, 102c, and 102d of the mold 100 using a pressing member 104 having a convex strip 103 having the same shape as the concave strip 102 of the mold as shown in FIG. And type. The cover canvas 25 is pushed into the recess 102 by pressing against the recess 102. If the cover canvas 25 is simultaneously pressed against the adjacent concave strips 102a and 102b, the length may be insufficient if the cover canvas 25 does not have sufficient slack within that range. Therefore, it is preferable to perform the pressing operation one by one in order, for example, pressing the concave strip portion 102a, pressing the concave strip portion 102b, and pressing the concave strip portion 102c. By doing so, the cover canvas 25 can be surely conformed to the shape of the concave portion. It is also possible to use a plain weave canvas or the like that does not have elasticity.

  The pressing member 104 may have one ridge 103 as shown in FIG. 4, but the member 104 having such one ridge 103 as shown in FIG. It is also possible to use a structure in which many pitches are connected so that the pitch of the concave stripes 102a, 102b, 102c, 102d of the mold 100 matches the pitch of the mold 100. When used, the scroll 103 is turned so that the ridge 103 faces outward, and the cover canvas 25 is pressed against the recess 102 a at the end of the mold 100 using the first ridge 103, so that the scroll is The cover canvas 25 is pressed against the concave portion 102b by the second convex portion 103, which is sequentially unwound. In this way, the cover canvas 25 can be pressed against the concave strips 102c and 102d to be molded.

  A suction hole 105 is provided in at least the concave portions 102a, 102b, 102c, and 102d of the mold 100. The suction hole 105 is connected to a vacuum pump or the like so that the cover canvas 25 is brought into close contact with the mold 100 and the molded shape is not broken even after the molded cover canvas 25 is sucked and the pressing member 104 is removed. Can do.

  When the suction hole 105 is sucked with the cover canvas 25 disposed, the cover canvas 25 is surely brought into close contact with the mold and good molding can be performed. However, if the suction is not performed yet, the suction hole 105 is sucked. As a result, air is sucked in any amount, and the suction force at the suction hole in which the cover canvas 25 is disposed is also reduced. Therefore, the cover canvas 25 can be brought into close contact with the mold 100 by providing an opening / closing valve or the like in the suction hole 105 so that suction is not performed in the suction hole in which the cover canvas 25 is not provided, Better molding can be performed.

  The cover canvas 25 pressed and molded by the pressing member 104 in this manner is sucked and brought into close contact with the mold 100, and the rubber sheet 107 is placed from above and pressed by the press plate 108 to thereby form the concave portion 19 on one side. A composite sheet 109 with a canvas, which becomes the inner layer 4a having irregularities including, is produced (FIG. 6). The composite sheet 109 is cut so as to have a predetermined circumference, and is wound around a cylindrical mold 111 using, for example, a spinning device as shown in FIG. A layer (not shown) is wound and vulcanized to form a sleeve.

  Further, the rubber sheet 114 to be the outer layer 4b and the cover canvas 24 are laminated (FIG. 8). Pressing between the lower mold 100 having an uneven shape meshing with the unevenness produced above and the upper mold 116 having an uneven shape for providing unevenness on the newly laminated rubber sheet 114, the outer mold side is pressed. As well as forming concaves and convexes including the concave portions 18, the rubber is vulcanized (FIG. 9). The entire circumference of the belt sleeve can be vulcanized by vulcanizing the unvulcanized portion in order. Then, the center belt can be manufactured by cutting to a predetermined width.

  By providing the position of the suction hole 105 at the bottom of the concave portions 102a, 102b, 102c, 102d of the mold 100, a protrusion made of rubber is formed on the top of the convex portion 26 of the completed center belt. be able to. By doing so, the fitting force when the center belt is fitted into the block 2 can be strengthened, and the movement between the center belt and the block can be prevented.

  In the present invention, as described above, the cover canvas 25 is pressed by the pressing member so that the rubber sheet is overlapped and formed after being aligned with the uneven shape of the mold. Even in the case of a strip or when a material having a high rigidity such as an aramid fiber is used as a material for a cover canvas, irregularities according to the mold can be formed reliably.

  The mold 100 used here may be a cylindrical one. When the cover canvas 25 is wound around the cylindrical mold 100, the ends need to be joined to each other. It can be joined by joining by means of superposition heat, ultrasonic waves, etc. with an allowance of about 1 to 3 mm. Thereafter, the unvulcanized rubber sheet 114 is wound and heated and pressed to form a composite sheet 109 with a canvas having irregularities formed thereon.

  The high load transmission belt 1 can be finally obtained by fitting the block 2 into the concave portions 18 and 19 of the center belt obtained as described above.

  Further, either a block in which an insert material made of, for example, an aluminum alloy is embedded in the block or a block in which no insert material is embedded can be used.

  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 nylon 46 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 as a tensile force to the center belts 3a and 3b, and a tension transmission type high load transmission belt can be configured.

  In addition to these, the lubricity of the block 2 can be improved by mixing at least one selected from molybdenum disulfide, graphite, and fluorine-based resin. Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), polyfluorinated ethylene propylene ether (PFPE), tetrafluoroethylene hexafluoropropylene copolymer (PFEP), polyfluorinated alkoxyethylene (PFA), and the like. .

  As the rubber 4 of the center belts 3a and 3b, a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, or rubber or polyurethane rubber obtained by appropriately blending these materials is used. Can be mentioned. And as the core 5, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used.

  Further, the cover canvas is made of aramid fiber, nylon fiber, polyester fiber, etc., and a canvas using a yarn in which these are mixed and a canvas using warp and weft can be used. If it is the method of this invention, the elasticity of cover canvas itself is not required, and a plain-weave canvas can be used. However, twill canvas and satin canvas can also be used.

  FIG. 10 shows an example of another belt to which the center belt obtained by the manufacturing method of the present invention can be applied. A pair of side pillars 32 and 33 extend upward from both ends of the beam portion 31. The lock portions 34 and 35 extending from the upper ends of the side pillars 32 and 33 toward the center of the block 2 are provided so as to face each other. The beam portion 31, the side pillars 32 and 33, and the lock portions 34 and 35 form a fitting groove 30 into which the center belts 3a and 3b are fitted. The center belts 3a and 3b are inserted into the fitting groove 30 through the opening between the lock portions 34 and 35 and attached. Further, a convex portion 37 is provided on each of the lock portions 34 and 35 on the fitting groove 30 side, and this convex portion 37 is fitted into the concave portion 36 provided at a predetermined pitch on the center belts 3a and 3b. To do. As a result, the center belts 3a and 3b are not easily removed from the block 2 after being mounted.

  INDUSTRIAL APPLICABILITY The present invention is used as a method for manufacturing a center belt that is a belt tension body used for driving automobiles, motorcycles, general industrial machines, agricultural machines, and the like.

It is a perspective schematic diagram showing an example of the high load transmission belt concerning the present invention. It is a sectional side view of a high load power transmission belt. It is sectional drawing of the place which put the cover canvas in the metal mold | die. It is sectional drawing when the unevenness | corrugation of the inner layer side was shape | molded with the metal mold | die. It is a front view which shows the example of a press member. It is sectional drawing of the place which has shape | molded the rubber sheet put on the cover canvas. It is a schematic diagram of spinning the core. It is sectional drawing of the place which laminated | stacked the rubber sheet and cover canvas of the outer layer side. It is sectional drawing of the place which shape | molds the unevenness | corrugation of the outer layer side with a metal mold | die. It is a perspective schematic diagram showing other examples of the high load power transmission belt concerning the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High load power transmission belt 2 Block 3a Center belt 3b Center belt 4 Rubber | gum 4a Inner layer 4b Outer layer 5 Core 11 Upper beam part 12 Lower beam part 13 Center pillar 14 Groove 15 Groove 16 Groove upper surface 17 Groove lower surface 18 Groove part 19 Groove Section 20 Projection section 21 Projection section 25 Cover canvas 100 Mold 101a Projection section 101b Projection section 101c Projection section 101d Projection section 102a Indentation section 102b Indentation section 102c Indentation section 102d Indentation section 103 Projection Part 104 Pressing member 106 Rubber sheet 110 Composite sheet 111 Mold 112 Core wire 113 Sleeve 114 Rubber sheet 116 Mold

Claims (4)

  Used for a high load transmission belt comprising a center belt in which a core body is embedded in rubber, and at least one surface of the center belt has irregularities with a predetermined pitch along the longitudinal direction, and the irregularities are fitted and fixed to the blocks. In the manufacturing method of a center belt made of rubber having a cover belt laminated on the surface, the cover canvas is arranged on a mold having an uneven shape, and the cover canvas is aligned with the uneven shape of the mold by a pressing member. And a step of vulcanizing by laminating the rubber sheets and heating and pressurizing them after removing the pressing member.   The center belt manufacturing method according to claim 1, wherein a suction hole is provided in at least a concave portion of the mold, and the cover canvas pressed against the mold by the pressing member is sucked to hold the uneven shape of the cover canvas.   3. The center belt according to claim 2, wherein the suction hole is provided in the bottom of the concave portion of the mold, and a rubber protrusion is formed on the convex portion of the center belt by forming the center belt while sucking. Manufacturing method. The center belt manufacturing method according to claim 2, wherein suction is not performed in a suction hole in which no canvas is arranged.

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