JP2008241035A - High load transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high load transmission belt preventing loose fitting between blocks and a center belt to prevent a failure such as cutting of the belt by suppressing wear and heat generation of a center belt side cover canvas caused by friction between the blocks and the center belt during the travel of the belt. <P>SOLUTION: The high load transmission belt 1 is provided with the center belt 3 with a tension member 5 spirally embedded in elastomer 4, and a plurality of blocks 2 along the longitudinal direction of the center belt 3, wherein the thickness of canvas 10 arranged on the lower side of the tension member at the bottommost part of a recess 16 on the lower face side of the center belt 3 accounts for 40-80% of the added thickness of the elastomer and canvas. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a high-load transmission belt in which blocks are fixed at a predetermined pitch along the longitudinal direction of a 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 continuously variable speed applications, it is necessary to use a belt that can withstand a high load especially for high load transmission applications where the life of conventional rubber belts is too short.

  Among such belts, there is a high-load transmission belt in which the block is fixed to the center belt and the strength in the belt width direction is increased. As a specific configuration, the core is made of an elastomer such as rubber. A block made of a relatively hard elastomer than the elastomer used for the center belt is secured to the center belt embedded in the center belt using a fastening material such as a bolt or a rivet. There is a belt having grooves on both side surfaces of the block, and a pair of center belts fitted into the grooves provided on the side surfaces.

  Such a tension transmission type high load transmission belt has a problem in that friction is always generated between the block and the center belt during running of the belt, and the center belt and the block are deteriorated due to stress concentration and heat generation. In addition, in the case of such a belt, since it is used as a continuously variable transmission as described above, it has a mechanism for shifting by changing the effective diameter of a pulley around which the belt is wound. It will be used with pulley diameter.

  Particularly when the belt is wound around a small pulley diameter, the lower surface side, which is the inner peripheral side of the center belt, is sandwiched between the blocks, stress is concentrated, and a large frictional force is generated, which constitutes the center belt. Deteriorated to cause cracks or cause belt cutting.

  In order to alleviate the concentration of stress applied to the center belt, Patent Document 2 sets so that the upper end of the convex portion provided on the lower surface of the center belt is positioned above the lower end position of the convex portion of the block. A belt has been proposed in which the convex portion of the center belt is not pinched by a block when the belt is wound around a pulley and bent.

  Further, in Patent Document 3, a gap between the block and the center belt is set by setting the curvature radius of the convex portion formed by the block smaller than the curvature radius of the concave portion formed on the inner peripheral surface of the center belt at the portion where the block and the center belt are fitted. A belt is disclosed which is provided with

Japanese Patent Laid-Open No. 63-34342 Japanese Patent Laid-Open No. 62-151646 Japanese Patent Laid-Open No. 9-25999

  By adopting the configuration described in Patent Document 2 and Patent Document 3, friction occurs between the block and the center belt due to the bending of the belt, and stress concentrates on the lower surface of the center belt, causing a crack in the center belt. In addition, it is possible to alleviate the occurrence of problems such as heat generation and melting of the canvas or deterioration of materials such as rubber.

  However, the center belt constrained by the block bends, especially by bending with a small pulley diameter, the friction between the block and the center belt is generated more strongly and heat is generated, and the lower surface is greatly compressed. However, the problem that internal heat generation occurs and leads to wear of the center belt cannot be solved.

  By using a high-strength aramid fiber as the material for the cover canvas as in Patent Document 4, it is possible to solve the problem that the canvas melts and cracks leading to the cutting of the belt. However, since the cutting occurs early when the canvas disappears due to wear, it is desirable to extend the life of the belt by further delaying the wear.

  Therefore, in the present invention, heat generation is prevented by reducing the friction generated between the block and the center belt during belt running, and the generated frictional force is small even when the belt is largely bent with a small pulley diameter. High load transmission belts that can prevent heat generation, prevent problems such as cutting the center belt, and extend the life of the belt by delaying the wear of the canvas. For the purpose of provision.

  In order to achieve the above-mentioned problem, in claim 1 of the present invention, a core body is embedded in an elastomer, a cover canvas is laminated on the surface, and a ridge and a ridge are formed at a predetermined pitch along the longitudinal direction. In a high-load transmission belt comprising a center belt formed alternately and a plurality of blocks fitted and disposed in the concave portion of the center belt, the lower side of the core at the bottom of the concave portion on the lower side of the center belt The thickness of the canvas disposed on the occupant occupies 40 to 80% of the total thickness of the elastomer and the canvas.

  According to a second aspect of the present invention, the cover canvas on the lower side of the center belt is the high load transmission belt according to the first aspect, which is made of an aramid fiber.

  According to a third aspect of the present invention, the cover canvas on the lower side of the center belt is a high load transmission belt according to the first aspect in which a canvas having a low wear fiber layer disposed at least on the side in contact with the block is used.

  According to a fourth aspect of the present invention, the low wear fiber layer is a high load transmission belt according to the third aspect of the present invention, which is made of fluororesin fibers.

  According to a fifth aspect of the present invention, the high load transmission belt according to the fourth aspect is provided, wherein the fluororesin fiber disposed on the cover canvas is a non-woven fabric and the basis weight is within a range of 10 to 200 g / m2.

  According to a sixth aspect of the present invention, the cover canvas is a high-load transmission belt according to any one of the fourth to fifth aspects, wherein the cover fabric is formed by laminating fluororesin fibers on the surface of a base fabric made of fibers other than fluororesin.

  In Claim 7, it is set as the high load power transmission belt of Claims 4-6 whose fluororesin is PTFE resin (tetrafluoroethylene resin).

  In Claim 8, it is set as the high load power transmission belt of Claim 3 in which a low abrasion fiber layer consists of a fiber made from a polyarylate resin.

  According to a ninth aspect of the present invention, the cover canvas is the high load transmission belt according to the eighth aspect, wherein the cover canvas is configured by laminating a polyarylate resin fiber on a surface of a base fabric made of a fiber other than the polyarylate resin.

  In claim 1, since the thickness of the cover canvas is set to be 40 to 80% with respect to the sum of the thickness of the elastomer located below the center body of the center belt and the canvas, the wear allowance is set. However, although the canvas wears, the time until it is worn can be delayed.

  According to the second aspect, the cover canvas provided on the lower surface of the center belt is a canvas made of aramid canvas, and wear can be further reduced.

  In claim 3, the cover canvas on the lower side of the center belt has a low wear fiber layer disposed at least on the side in contact with the block, and wears even if friction occurs with the block because the friction coefficient is low. In addition, since the heat generation is reduced, it is possible to prevent the problem that the cover canvas is worn or melted and cut.

  According to the fourth aspect, the fluororesin fibers are disposed as the low wear fiber layer, and the fluororesin fibers have a low coefficient of friction, so that they do not wear even when friction occurs between the blocks and generate less heat. Therefore, it is possible to prevent the problem that the cover canvas is melted and cut.

  In Claim 5, the fluororesin fiber to be used is a non-woven fabric, and the basis weight thereof is limited to a predetermined range, so that the effect of suppressing wear resistance and heat generation can be raised to a higher level.

  According to a sixth aspect of the present invention, the cover canvas has a structure in which fluororesin fibers are laminated on the surface of a base cloth made of fibers other than the fluororesin fibers, and the strength of the cover canvas is ensured by providing the base cloth and the center belt. Adhesive strength with an elastomer such as rubber that constitutes can be made sufficient.

  In claim 7, the fluororesin is PTFE resin (tetrafluoroethylene resin), and the effect of suppressing wear resistance and heat generation is high among fluororesins.

  According to claim 8, polyarylate resin fibers are arranged as the low wear fiber layer, and the polyarylate resin fibers have a low coefficient of friction and excellent wear resistance, and therefore wear even if friction occurs between the blocks. Since the heat generation is reduced, the problem that the cover canvas melts and cuts can be prevented.

  According to a ninth aspect of the present invention, the cover canvas has a structure in which polyarylate resin fibers are laminated on the surface of the base cloth made of fibers other than the polyarylate resin fibers, and the strength of the cover canvas is ensured by providing the base cloth. At the same time, the adhesive strength with an elastomer such as rubber constituting the center belt can be made sufficient.

  FIG. 1 is a schematic perspective view showing an example of a high load transmission belt 1 according to the present invention, and FIG. 2 is a side sectional view thereof. The high load transmission belt 1 of the present invention is attached to two center belts 3 of the same width formed by embedding a rope-like core body 5 in an elastomer 4 in a spiral shape, and attached to the center belt 3 at a predetermined pitch. It is composed of a plurality of blocks 2. The side faces 6 and 7 of the block have fitting grooves 8 and 9, and the center belt 3 is mounted in the fitting grooves. Both side surfaces 6 and 7 of the block 2 are inclined surfaces that come into contact with the V-grooves of the pulley, receive power from the driven pulley, pull the center belt 3 that is locked and fixed, and drive pulley Is transmitted to the driven pulley. A cover canvas 10 which is a feature of the present invention is laminated on the surface of the center belt 3 integrally with the center belt 3.

  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. As described above, the fitting grooves 8 and 9 of the center belt 3 are formed, and the groove upper surface and the groove lower surface in the fitting grooves 8 and 9 are formed on the groove 15 and the lower surface provided on the upper surface of the center belt 3. Convex ridges 17 and 18 that engage with the provided concave ridges 16 are provided, and they are engaged with each other by irregularities.

  FIG. 3 is an example of another belt, and a pair of side pillars 22 and 23 extend upward from both ends of the beam portion 21, and the upper ends of the side pillars 22 and 23 respectively extend toward the center of the block 2. The extending lock portions 24 and 25 are provided to face each other. The beam portion 21, the side pillars 22 and 23, and the lock portions 24 and 25 form a fitting groove 20 into which the center belt 3 is fitted. The center belt 3 is inserted into the fitting groove 20 through the opening between the lock portions 24 and 25 and attached. Further, convex portions 27 are respectively provided on the side of the fitting grooves 20 of the lock portions 24 and 25, and the convex portions 27 are fitted to the concave strip portions 26 provided on the center belt 3 at a predetermined pitch. To do. As a result, the center belt 3 is not easily removed from the block 2 after being mounted. A cover canvas 10 is laminated on the surface of the center belt 3 integrally with the center belt 3.

  The cover canvas 10 disposed on both the upper and lower sides of the center belt 3 protects the center belt from friction between the center belt and the block that occurs during belt running. In the present invention, at least the thickness of the cover canvas 10 disposed on the lower surface of the center belt is set within a range of 40 to 80% with respect to the sum of the thickness of the elastomer located below the center body 5 of the center belt and the thickness of the canvas 10. ing. It is set relatively thicker than a normal belt. As the belt travels, it rubs between the block and the center belt, and the canvas on the surface wears in the concave portion of the center belt where the block is fitted. When it disappears, the internal elastomer cracks and leads to cutting of the belt. By increasing the thickness of the canvas as in the present invention, a large amount of wear can be ensured, and although the canvas is worn, the time until it is worn can be delayed.

  When the thickness t of the cover canvas 10 is less than 40% with respect to the total thickness T of the elastomer and the canvas positioned below the center body 5 of the center belt 3, the canvas is worn out at an early stage. Will lead to cutting. Further, if it exceeds 80%, the thickness of the elastomer portion becomes thin and the cushion effect for protecting the core body 5 becomes too small, and the bending fatigue of the core body 5 is promoted, which is not preferable. .

  An aramid fiber can be used as a material for the cover canvas 10 disposed on the lower surface side of the center belt. The aramid fiber is a fiber having excellent wear resistance, and is combined with the configuration in which the thickness of the canvas is set large as described above. It is possible to make the time during which the wear occurs longer. The cover canvas 10 to be used may be entirely composed of aramid fibers, but may be used in combination with other fibers such as polyamide fibers.

  Further, a low wear fiber layer is disposed on at least the side of the cover canvas 10 disposed on the lower surface side of the center belt in contact with the block 2, and examples of the low wear fiber layer include a fluororesin fiber or a polyarylate resin fiber. Is mentioned. In particular, the arrangement on the lower surface of the center belt that generates a large amount of heat is an indispensable requirement. Of course, not only the lower surface of the center belt but also the cover canvas 10 on the upper surface can be configured in the same manner, and the effects described below can be further improved. It can be said that this is a preferable form. The low wear fiber layer made of fluororesin or polyarylate resin itself is a material having a low friction coefficient, and even if it rubs against the block 2, it is not easily worn, and heat generated by friction is extremely small. If there is movement between the block and the center belt while the belt is running, the cover canvas on the center belt side will be worn or melted due to heat, resulting in a problem such as cutting the center belt. It was connected. However, placing the fluororesin fiber on the side of the cover canvas that is in contact with the block 2 eliminates the problems of wear and heat generation, and prevents the center belt from being cut due to them, and consequently the belt failure, thus extending the service life. Is something that can be done.

  The fluororesin that can be used as the fluororesin fiber is tetrafluoroethylene resin (PTFE), tetrafluoroethylene / perfluoroalkoxyethylene copolymer resin (PFA), tetrafluoroethylene / hexafluoropropylene copolymer Combined resin (PFEP), tetrafluoroethylene / ethylene copolymer resin (PETFE), vinylidene fluoride resin (PVDF), vinyl fluoride resin (PVF), chlorotrifluoroethylene resin (CTFE), ethylene / chlorotrifluoro Examples thereof include ethylene resin (ECTFE) and ethylene / tetrafluoroethylene copolymer resin (PETFE). Among these, it is preferable to use tetrafluoroethylene resin (PTFE) in terms of reducing wear resistance and heat generation. Examples of the form include various forms such as a woven fabric and a non-woven fabric.

  As the polyarylate resin fiber, a fiber made of a polyarylate (fully aromatic polyester) resin such as Kuraray's trade name Vectran can be used.

  The fibers arranged on the lower surface side of the cover canvas 10 may be a canvas made of only a fluororesin fiber or a polyarylate resin fiber, but not only that, but a base fabric made of a fiber other than the fluororesin as shown in FIG. 10a may be formed by laminating and arranging fluororesin fibers or polyarylate as a low wear fiber layer 10b on the surface of 10a. By providing the base fabric 10a, the cover canvas 10 of the center belt 3 has high strength. In addition, although the fluororesin generally has poor adhesiveness, it can be bonded to the elastomer 4 such as rubber constituting the center belt 3 by using fibers other than the low wear fiber layer 10b as the base fabric 10a. The power can be high enough. In that case, as the base fabric 10a, polyamide fibers such as 6,6-nylon, polyester fibers such as PET, aramid fibers, cotton, and polyparaphenylene benzobisoxazole fibers can be generally used. Can be used. Examples of the canvas composition include plain weaves, twill weaves and satin weaves.

  The low abrasion fiber layer 10b is laminated on the base fabric 10a. For example, the low abrasion fiber layer 10b can be laminated by the following method. A fiber of about 5 to 50 mm in fiber length made of fluororesin or polyarylate resin is entangled in a web shape and compressed into a sheet-like nonwoven fabric, which is laminated and integrated with the base fabric 10a by hydroentangling The cover canvas 10 in which the non-woven fabric made of low wear fibers is arranged on one side can be obtained.

  When the nonwoven fabric is used for the low wear fiber layer 10b, the basis weight is preferably in the range of 10 to 200 g / m2. If it is less than 10 g / m 2, the wear resistance tends to be insufficient, and if the belt is run for a long time, the amount of wear increases and the block 2 and the center belt 3 are loosely fitted. Further, if the weight per unit area exceeds 200 g / m2, the thickness increases, and the belt is compressed between the block 2 and the center belt 3 while the belt runs for a long period of time. Absent.

  A material used as the elastomer 4 of the center belt 3 is a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, chlorosulfonated polyethylene, alkylated chlorosulfonated polyethylene or the like. And rubber or polyurethane rubber blended appropriately. And as the core 5, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used. The core body 5 may be made of a woven fabric, a knitted fabric, a metal thin plate, or the like of the above-mentioned fiber other than a rope embedded in a spiral shape.

  Adhesion treatment is performed to laminate and bond the cover canvas 10 having such a configuration to the surface of the center belt 2. Examples of the adhesion treatment include treatment with an RFL solution, an isocyanate solution, or an epoxy solution. The RFL solution is a mixture of an initial condensate of resorcin and formalin mixed with latex. Examples of latex used here include styrene / butadiene / pyridine terpolymers, hydrogenated nitrile rubber, chlorosulfonated polyethylene, epichlorohydrin, and the like. The latex. Further, a pasting process in which a rubber paste dissolved in a solvent is attached to the surface of the cover canvas 10 can also be cited as an adhesive process.

  In these adhesion treatments, by adding a friction coefficient reducing material to an adhesion treatment agent such as an RFL solution, an isocyanate solution, an epoxy solution, or rubber glue, the friction coefficient between the block 2 and the cover canvas 10 of the center belt 3 is further increased. Wear and heat generation due to friction between the block 2 and the center belt 3 can be prevented in combination with the arrangement of the fluororesin fibers. Specific examples of the friction coefficient reducing material include tetrafluoroethylene resin, ethylene trifluoride resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, and tetrafluoroethylene-perfluoroalkoxyethylene copolymer resin. Fluorine resin such as tetrafluoroethylene-ethylene copolymer resin, ceramic powder, glass beads, ultra high molecular weight polyethylene, graphite, molybdenum disulfide, phenol resin, glass fiber, carbon fiber, aramid fiber, etc. , At least one of these, preferably ceramic powder, glass beads, ultrahigh molecular weight polyethylene, graphite, molybdenum disulfide, tetrafluoroethylene resin (PTFE) resin or other fluororesin, or phenol resin More preferably ethylene tetrafluoride tree It is preferable to use a fluorocarbon resin (PTFE resin) and the like.

  The block 2 may be made of a resin composition or a reinforcing material having the same shape as that of a block made of metal or the like and having a resin composition coated on the surface. The block with reinforcement is superior in strength and has a stable shape and is not easily deformed even when stressed, but it has the disadvantage of increasing the weight and centrifugal force during belt running. Have On the other hand, the block that does not have a reinforcing material is light in weight, so it has the advantage that the centrifugal force generated during belt running is small and suitable for use at high speeds, but it is easily deformed when stressed. There are disadvantages such as.

  The resin material constituting the block 2 has a relatively large coefficient of friction and excellent wear resistance, and has higher rigidity than the elastomer 4 constituting the center belts 3a and 3b. Specifically, the hardness is 90 ° JIS A or higher. Hard rubber, hard polyurethane resin, liquid crystal resin, thermosetting resin such as phenol resin, epoxy resin, polyester resin, acrylic resin, methacrylic resin, polyamide resin such as 4,6-nylon, 9, T-nylon, polyamide Thermoplastic resins such as imide (PAI) resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin, polyimide (PI) resin, polyether sulfone (PES) resin, polyether ether ketone (PEEK) resin are used. It is done.

  Also, in these resins, cotton yarn, woven fabric made of chemical fiber such as polyamide fiber and aramid fiber, glass fiber, metal fiber, carbon fiber, filler, zinc oxide whisker, potassium titanate whisker, aluminum borate whisker, etc. Made of reinforced resin mixed with inorganic materials such as whisker, silica and calcium carbonate.

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

  Reinforcing material is a reinforcing material that provides the side pressure resistance and bending rigidity of block 2, and materials such as aluminum alloy, ceramics, composite material of ceramics and aluminum, carbon fiber reinforced resin and iron are used. Can be mentioned.

  In terms of imparting lateral pressure resistance and bending rigidity, a metal material is preferable. Among the metal materials, the elastic modulus of an aluminum alloy is 7000 kgf / mm 2 and the specific gravity is 2.8, whereas iron has an elastic modulus of 22000 kgf / It is said that the specific gravity is 7.8 mm2 and iron is higher in strength. However, for belts that rotate at high speed, the weight of the belt greatly affects the life, so an aluminum alloy that is advantageous in terms of weight reduction should be used. It is preferable to use it.

  The lower beam of the block 2 must be allowed to be bent so that the belt can be wound around the pulley, and an inclined surface is provided on at least one of the front and rear surfaces in the belt traveling direction. By providing the inclined surface, the belt can be bent without buffering between the blocks.

  In the present embodiment, the case where the two center belts 3 are used and mounted in the fitting groove 20 of the block 2 has been described. However, another center belt may be used. .

  The present invention can be applied to the manufacture of belts that change the effective diameter of pulleys and transmit large torque, such as continuously variable transmissions for automobiles, motorcycles, and agricultural machines.

It is a principal part perspective view of the high load power transmission belt of this invention. It is a side view of the high load power transmission belt of the present invention. It is a perspective view of the high load transmission belt which shows another example of this invention. It is a principal part side view of a cover canvas.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 High load power transmission belt 2 Block 3 Center belt 4 Elastomer 5 Core body 6 Side surface 7 Side surface 8 Fitting groove 9 Fitting groove 10 Cover canvas 10a Base fabric 10b Low wear fiber layer 11 Upper beam portion 12 Lower beam portion 13 Center pillar 15 Concave line part 16 Concave line part 17 Convex line part 18 Convex line part

Claims (9)

  A center belt in which a core body is embedded in an elastomer and a cover canvas is laminated on the surface, and a ridge portion and a ridge portion are alternately formed at a predetermined pitch along the longitudinal direction, and the center belt is fitted into the ridge portion of the center belt. In a high-load transmission belt composed of a plurality of blocks arranged together, the thickness of the canvas disposed below the core at the bottom of the concave portion on the lower surface side of the center belt is 40-80, which is the combined thickness of the elastomer and the canvas. High load transmission belt, characterized by   The high load transmission belt according to claim 1, wherein the cover canvas on the lower side of the center belt is made of aramid fiber.   The high load transmission belt according to claim 1, wherein the cover canvas on the lower side of the center belt is a canvas having a low wear fiber layer disposed on at least a side in contact with the block.   4. The high load transmission belt according to claim 3, wherein the low wear fiber layer is made of a fluororesin fiber. Heavy duty power transmission belt according to claim 4, wherein the fluorine resin fibers arranged in the cover canvas is in the range is basis weight nonwoven of 10 to 200 g / m ^2.   6. The high load transmission belt according to claim 4, wherein the cover canvas has a configuration in which fluororesin fibers are laminated on the surface of a base fabric made of fibers other than fluororesin.   The high load transmission belt according to claim 4, wherein the fluororesin is PTFE resin (tetrafluoroethylene resin).   4. The high load transmission belt according to claim 3, wherein the low wear fiber layer is made of a polyarylate resin fiber.   9. The high load transmission belt according to claim 8, wherein the cover canvas has a configuration in which polyarylate resin fibers are laminated on the surface of a base fabric made of carbon fibers.

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