JP2010230146A - Transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission belt whose flexibility is held in a good state without employing cover sailcloth in a tensile rubber layer and whose vibration is reduced to lengthen its operating life and which is better suited for compact design. <P>SOLUTION: The transmission belt 1 is arranged with a compressible rubber layer 6 and an extendable rubber layer 5 adjacently to an adhered rubber layer 2 embedded with a core wire 3, wherein the compressive rubber layer 6 has a cog portion 12 arranged alternately with a cog ridge portion 9 and a cog trough portion 8, and the cover sailcloth is not arranged on a backside of the belt. Then, the extendable rubber layer 5 is embedded with at least one reinforced layer 13 composed of fiber reinforced resin arranged with fiber in the width direction of the belt 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a power transmission belt, and more particularly to a power transmission belt used as a high-load transmission belt in a snowmobile, a scooter and a general industrial belt.

  Conventionally, in a drive system of a scooter, buggy, snowmobile (snowmobile), or general industrial machinery field, a transmission belt is suspended between a drive pulley and a driven pulley, and a belt that changes speed by changing the effective diameter of the pulley. A type transmission is used. The power transmission belt used here has a cog that has cog crests and cog troughs alternately arranged on both the compressed rubber layer and the stretched rubber layer or on the rubber layer of the compressed rubber layer. It has a configuration embedded in a rubber layer and is known as a low-edge cogged belt such as a low-edge double cogged belt or a low-edge single cogged belt.

  Since these belts receive a large lateral pressure from the pulleys while the belt is running, the belt may be deformed such as a dishing phenomenon in which the cross-sectional shape is curved downwardly like a dish. When dishing occurs, there are problems such as slipping of the belt and peeling of members such as a core wire constituting the belt. Therefore, it is conceivable to reinforce with a material such as fiber so that the belt does not deform. For example, if the entire surface of the belt is covered with a cover canvas, an effect is obtained in the sense that the belt is prevented from being deformed and the shape is maintained, but on the other hand, the flexibility is impaired, so when used with a small-diameter pulley In addition, there are problems that the belt runs in a state where the belt is not sufficiently along the pulley and causes slip, or that the belt is cracked on the back side of the belt by forcibly bending. Various devices have been made to improve the flexibility.

  In the case of a double cogged belt, as disclosed in Patent Document 1 and Patent Document 2, a cover canvas is not laminated on the surface of the stretched rubber layer on the back surface, and rubber is exposed, or disclosed in Patent Document 3 and Patent Document 4. As shown in the figure, there was a cover canvas laminated on the surface of the stretch rubber layer on the back.

  Those with no cover canvas are superior in terms of belt flexibility, but are inferior in bell shape retention, causing vibration during running, leading to faster wear and poor transmission efficiency. There was a problem, in particular, the vibration on the loose side of the belt wound around the pulley was large, which prevented the belt case in the engine from being made compact.

  On the other hand, in the case of the cover canvas laminated on the back of the belt, the belt shape is stable and vibration during running can be greatly reduced, but the belt bends repeatedly to deteriorate the flexibility. As a result, there was a problem that the surface cracked and caused cutting.

  Patent Document 5 seems to improve the lateral pressure resistance and wear resistance against the excessive side pressure received from the pulley by embedding the belt width direction not only in the compressed rubber layer of the belt but also in the stretched rubber layer. Belts are disclosed.

JP 2001-41292 A JP 2001-263432 A JP 2001-263431 A JP 2001-317596 A JP 2006-153038 A

  Improving the shape retention of the belt to prevent vibration of the running belt and improving the flexibility of the belt to prevent the occurrence of cracks are contradictory performances as described above. If one of the performances is satisfied, that is, if the performance of one is improved, the performance of the other will be reduced.

  Therefore, in the present invention, for transmission with a high shape retaining property that can maintain high transmission efficiency during belt running without impairing the flexibility of the belt and prevent vibration of the belt to reduce noise generation. The purpose is to provide a belt.

  In order to achieve the above-mentioned object, the invention described in the claims of the present application includes a compression rubber layer and a stretch rubber layer adjacent to the adhesive rubber layer in which the core wire is embedded, and at least the compression rubber layer has a cog mountain portion and a cog valley portion. In a transmission belt having cogs that are alternately arranged, a reinforcing layer made of a fiber reinforced resin is embedded in the stretched rubber layer or laminated on the surface of the stretched layer, and the fiber constituting the fiber reinforced resin Is oriented in the belt width direction.

  In Claim 2, the fiber constituting the fiber reinforced resin used as the reinforcing layer is a carbon fiber.

  According to a third aspect of the present invention, the resin constituting the fiber reinforced resin used as the reinforcing layer is a thermosetting resin.

  According to a fourth aspect of the present invention, there is provided the transmission belt according to the third aspect, wherein the thermosetting resin constituting the fiber reinforced resin used as the reinforcing layer is an epoxy resin.

  According to a fifth aspect of the present invention, the transmission belt according to any one of the first to fourth aspects, wherein no cover canvas is disposed on the stretched rubber layer.

  In the power transmission belt of the present invention, the reinforcing layer made of fiber reinforced resin is embedded in the stretched rubber layer or laminated on the surface of the stretched rubber layer, so that the belt has excellent shape retention and does not cause dishing. Therefore, it is possible to provide a transmission belt that can increase transmission efficiency and also can suppress generation of vibration during traveling.

  According to claim 2, the fiber used for the reinforcing layer is limited to the carbon fiber, the strength and wear resistance of the reinforcing layer can be improved, and it can withstand a large side pressure from the pulley even under high load conditions. And the effect of reducing wear on the side surface of the belt can be expected.

In claim 3, the resin used for the reinforcing layer is limited to a thermosetting resin, and in claim 4, the thermosetting resin is limited to an epoxy resin, and the strength and wear resistance of the reinforcing layer are high, and the belt resistance. Side pressure, shape retention and wear resistance can also be improved.

  According to the fifth aspect of the present invention, the stretch rubber layer is intended for a belt in which no cover canvas is disposed, and the belt is apt to be deteriorated in its belt shape, and is reinforced with a fiber reinforced resin in which fibers are oriented in the belt width direction. By embedding the layer in the stretched layer, the shape can be sufficiently retained, and the flexibility of the belt is not significantly impaired.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a partial front view of a transmission belt according to the present invention, and FIG. 2 is a partial front view of another transmission belt according to the present invention.

  The power transmission belt 1 of the present invention has a core wire 3 made of a fiber cord embedded in an adhesive rubber layer 2, and has an extended rubber layer 5 in a state where the rubber is exposed on the back surface above the adhesive rubber layer 2. In the lower part, there is a compressed rubber layer 6 in which a cover canvas 4 is laminated. The compressed rubber layer 6 is provided with lower cog portions 12 in which cog valley portions 8 and cog mountain portions 9 are alternately arranged at a constant pitch along the belt longitudinal direction. In the stretched rubber layer 5, a single reinforcing layer 13 is embedded in the rubber at a position near the center in the height direction.

  The transmission belt 1 shown in FIG. 1 does not have a cover canvas on the back surface in order to give the belt excellent flexibility. In general, a belt without a cover canvas is easily deformed, and the belt is bent or twisted not only in the longitudinal direction but also in the lateral direction, so that the shape retainability is not high. Therefore, there is a problem in that belt vibration is generated due to deformation during belt running. However, especially when a cover canvas is arranged on the back of the belt, the flexibility of the belt is lowered, and therefore cracks are likely to occur due to repeated bending.

  Accordingly, in the present invention, the cover canvas is not disposed on the surface on the back side of the belt, and a reinforcing layer made of fiber reinforced resin is embedded in the stretched rubber layer 5 or laminated on the surface, and the fibers constituting the fiber reinforced resin Are oriented in the belt width direction. By doing so, the lateral rigidity of the belt can be given, so that shape retention can be improved, and the fact that the fibers are oriented in the width direction also contributes to not hindering the flexibility of the belt. ing. In FIG. 1, the reinforcing layer 13 is arranged at the approximate center in the thickness direction in the stretched rubber layer 5, but it may be provided in such a manner that it is laminated on the back surface of the belt as shown in FIG. 2. When priority is given to the bending of the belt, it is preferable to carefully embed it in rubber, but it is more advantageous to laminate it on the surface in order to protect the back of the belt.

  The reinforcing layer 13 can be embedded not only in the stretched rubber layer 5 but also in the compressed rubber layer 6 as shown in FIG. By disposing the reinforcing layer 13 in the compressed rubber layer 6 as well, the belt shape retention can be further improved, and the occurrence of vibration during belt running can be further reduced.

  By using fiber reinforced resin as the reinforcing layer 9, the side pressure resistance and shape retention of the belt can be greatly improved. Examples of fibers used for the fiber reinforced resin include carbon fibers, and examples of the thermosetting resin impregnated in the fibers of the reinforcing layer 9 include epoxy resins. The fibers used for the reinforcing layer are preferably aligned in the belt width direction for the purpose of improving the lateral pressure resistance and shape retention of the belt. For example, as shown in FIG. 4, a plurality of reinforcing layers 9 may be arranged so that fibers of all the reinforcing layers are arranged in the belt width direction, or a combination of fibers arranged in the width direction and the longitudinal direction is used. It is also possible to do. However, orienting the carbon fibers in the longitudinal direction of the belt inhibits the bendability of the belt, so that all preferred forms are oriented in the width direction.

  As a method for embedding and arranging the reinforcing layer 9 made of such a fiber reinforced resin in the stretched rubber layer, an unvulcanized rubber sheet for forming the compressed rubber layer 6 is wound around a cylindrical mold, and then, Wrap a rope to be the core 3, an unvulcanized rubber sheet to be the adhesive rubber layer 2, an unvulcanized rubber sheet to be the stretch rubber layer 5, and impregnate the fiber with a semi-cured thermosetting resin. Prepare prepregs, laminate them, wrap a rubber sheet from above, vulcanize the rubber along the shape of the mold by heating and pressurizing, and complete the thermosetting resin of the prepreg in the stretch rubber layer And can be integrally disposed in the belt. By disposing the rubber sheet on the prepreg, the rubber layer can be laminated on the surface of the stretched rubber layer 5.

  By embedding such a reinforcing layer 9 in the stretched rubber layer 5 or laminating on the surface, it is possible to improve the lateral pressure resistance and shape retention of the belt, preventing dishing during belt running and reducing transmission efficiency, Generation of vibration and noise can also be reduced.

  As the core wire 3, a polyester fiber, an aramid fiber, and a glass fiber are used, and the total number of deniers obtained by twisting together polyester fiber filament groups mainly composed of ethylene-2,6-naphthalate is 4,000 to 8, A cord subjected to adhesion treatment of 000 is preferable in order to reduce the belt slip ratio and extend the belt life. The number of upper twists of this cord is 10 to 23/10 cm, and the number of lower twists is 17 to 38/10 cm. When the total denier is less than 4,000, the modulus and strength of the cord are too low. When the total denier is more than 8,000, the belt becomes thick and the bending fatigue property is deteriorated.

  Ethylene-2,6-naphthalate is usually synthesized by condensation polymerization of naphthalene-2,6-dicarboxylic acid or an ester-forming derivative thereof with ethylene glycol in the presence of a catalyst under appropriate conditions. At this time, if one or more appropriate third components are added before the polymerization of ethylene-2,6-naphthalate is completed, a copolymer polyester is synthesized.

  The cord subjected to the bonding treatment can be finished into a belt having a high modulus by setting the spinning pitch, that is, the winding pitch of the core wire to 1.0 to 1.3 mm. If the length is less than 1.0 mm, the cord cannot ride on the adjacent cord and cannot be wound. On the other hand, if the length exceeds 1.3 mm, the modulus of the belt gradually decreases.

  In the other transmission belt 1 shown in FIG. 5, the stretched rubber layer 5 also has the upper cog portions 11 in which the cog mountain portions 9 and the cog valley portions 8 are alternately arranged so that the reinforcing layer 13 follows the cog shape. It is embedded in the stretched rubber layer 6 in a curved state. The reinforcing layer 13 is also embedded in the compressed rubber layer 5. As a result, the compression rubber layer 6 and the stretched rubber layer 5 have increased lateral pressure resistance without embedding short fibers in the belt width direction.

  The rubber composition to be the compression rubber layer 6 and the stretch rubber layer 5 is natural rubber, butyl rubber, styrene-butadiene rubber, chloroprene rubber, ethylene-propylene rubber, alkylated chlorosulfanated polyethylene (ACSM), hydrogenated nitrile rubber. A rubber material such as a mixed polymer of hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt alone or a mixture thereof is used, and carbon black, plasticizer, anti-aging agent, processing aid, which are usually used for this, It can be used together with pressure-sensitive adhesives, vulcanization accelerators, short fibers and the like.

  The cover canvas 4 is not necessarily provided. If the arrangement of the cover canvas is omitted, the flexibility of the belt is positive, and even when used with a small pulley diameter, the belt bends well, causing cracks from the belt surface or slipping between the pulleys. Can be improved. However, in general, a belt without a cover canvas is easily deformed, and the belt is bent or twisted not only in the longitudinal direction but also in the lateral direction, so that it cannot be said that the shape retaining property is high. Therefore, there is a problem in that belt vibration is generated due to deformation during belt running. In the present invention, since the reinforcing layer made of fiber reinforced resin is embedded in the compressed rubber, it has the effect of improving the lateral pressure resistance of the belt and reinforcing against deformation such as torsion. The belt shape retention can be improved while reducing the decrease as much as possible.

  The cover canvas 4 is made of cotton, polyester fiber, nylon, or the like, and is woven into plain weave, twill weave, satin weave, or the like, and may be a wide angle canvas in which the crossing angle between the warp and the weft is about 90 to 120 °. The reinforcing cloth 4 is subjected to RFL treatment, and then the rubber composition is subjected to fiction and coaching to obtain a canvas with rubber. The RFL liquid is obtained by mixing an initial condensate of resorcin and formalin into a latex. Examples of the latex used here include chloroprene, styrene / butadiene / vinylpyridine terpolymer, hydrogenated nitrile, NBR, and the like.

Further, the RFL liquid has a solids mass ratio of resorcin / formaldehyde initial condensate and rubber latex of 1/1 to 1/5, and the solid content of the RFL liquid is 3 to 10% by mass. It is preferable for enhancing the effect of adhesive force. If it exceeds 1/1, the cohesive force of the short fibers becomes large and the dispersibility becomes poor. Conversely, if it becomes less than 1/5, the adhesive strength between the rubber and the short fibers decreases, and the tensile strength also decreases. Further, when the solid content adhesion amount of the RFL liquid exceeds 10% by mass, the treatment liquid is hardened and it becomes difficult to split the filaments of the short fibers. The improvement effect of strength cannot be expected. Rubber latex includes styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer, EPDM, CSM. And latex such as ACSM.
Hereinafter, the effects of the present invention will be confirmed by more specific experimental examples.

Example 1
As Example 1, a cogged belt in which a compression rubber layer has a cog portion and a reinforcing layer made of a fiber reinforced resin is disposed in the stretched rubber layer at a position 1/2 the thickness above the core wire was prepared. The fiber reinforced resin was a prepreg obtained by impregnating carbon fiber with an epoxy resin, and the epoxy resin content was 33%. The carbon fiber was hardened with the epoxy resin in a state of being oriented in the belt width direction, immersed in an RFL solution, heat-treated, and further rubber paste was soaked.

  A 2 × 3 twisted structure in which 1,500 denier aramid fibers (trade name: Twaron) are twisted in the up and down direction with an upper twist number of 19.7 times / 10 cm and a lower twist number of 15.8 times / 10 cm. And an unprocessed code with a total denier of 9,000 was prepared. Next, this untreated cord was pre-dipped with an isocyanate-based adhesive, then dried at about 170 to 180 ° C., immersed in an RFL solution, and then stretched and heat-fixed at 200 to 240 ° C. to obtain a treated cord.

  As the cover canvas, a wide-angle plain woven canvas using a 50:50 blended yarn of aramid fiber (trade name: Twaron) and polyethylene terephthalate fiber in a weight ratio was used. These canvases were immersed in an RFL solution and then heat treated at 150 ° C. for 2 minutes to obtain treated canvases. Thereafter, a rubber composition was friction coated with these treated canvases to obtain rubberized canvases.

  A rubber composition made of chloroprene rubber containing short aramid fibers was used for the compression rubber layer and the stretch rubber layer, and a rubber composition made of chloroprene rubber containing no short fibers was used for the adhesive rubber layer.

  As a cog pad, a laminate of one reinforcing cloth and a sheet for a compressed rubber layer with a predetermined thickness is placed on a flat cog mold in which teeth and grooves are arranged alternately, and the cog is pressed by pressing at 75 ° C. Was formed into a typed cog pad. Both ends of the cog pad were cut vertically from the top of the cog crest.

  After these materials are prepared, a cog pad is wrapped around the inner mold attached to the mold and jointed, and then an adhesive rubber sheet having a predetermined thickness is joined, and then a core wire and a flat stretched rubber layer are wound around in order. Was made. Then, the jacket was put on and the mold was placed in a vulcanizing can and vulcanized to obtain a belt sleeve. This sleeve was cut into a V shape by a cutter to finish a transmission belt (size: upper width 22.0 mm, thickness 11.0 mm, outer peripheral length 850 mm) which is a low edge cogged belt.

  A durability running test was performed using the obtained belt. The results (belt life and its cause of failure) are shown in Table 1. In the durability running test, the belt is suspended on a biaxial horizontal running test machine arranged in a thermostatic bath consisting of a driving pulley having a diameter of 120 mm and a driven pulley having a diameter of 90 mm, and the input torque is set to 2.0 kgf. A load of 80 kgf was applied, and the rotation speed was varied at 6,000 rpm ± 500 rpm, and the ambient temperature was 90 ° C.

(Comparative Example 1)
In Comparative Example 1, a reinforcing layer was not embedded in the stretched rubber layer, but instead, a wide belt with a plain weave on the surface and a warp and weft crossing angle of 120 ° was used, and a belt exactly the same as in the example was created. An endurance running test was conducted under the same conditions. The results are shown in Table 1.

(Comparative Example 2)
In Comparative Example 2, a belt exactly the same as that of the example was prepared except that the reinforcing rubber layer was buried in the stretched rubber layer instead of the reinforcing layer made of fiber reinforced resin, and the durability running test was performed under the same conditions. The results are shown in Table 1.

  As a result, Example 1 was canceled because it traveled for a considerable time. Later, it finally failed due to cracks in the cog valley, and the retention layer of the belt shape was improved by the reinforcing layer made of fiber reinforced resin embedded in the stretched rubber layer. Conceivable.

  On the other hand, in Comparative Example 1 in which no reinforcing material was embedded in the compressed rubber layer, the life of the core was reached in a short time due to the occurrence of pop-out of the core, and the shape of the belt could not be maintained. It is presumed that delamination occurred at the part.

  Moreover, in the comparative example 2 which embedded the reinforcement layer of the saddle which consists of an aramid fiber, it has failed by the pop-out of the core wire earlier than the example, and for the example using the fiber reinforced resin as the reinforcement layer It seems that the fiber diameter was large and the strain of the stretched rubber increased when bent, resulting in a failure in a short time.

  Also from the above, in the present invention, by arranging the reinforcing layer made of fiber reinforced resin in the stretched rubber layer, the shape stability of the belt can be secured, the transmission efficiency is high, and the belt having a longer life is obtained. I found out that I can do it.

  The power transmission belt of the present invention is suitable for snowmobiles, scooters and general industrial transmission belts.

It is a partial front view of the transmission belt according to the present invention. It is a partial front view of the other power transmission belt according to the present invention. It is a partial front view of the other power transmission belt according to the present invention. It is a partial front view of the other power transmission belt according to the present invention. It is a partial front view of the other power transmission belt according to the present invention.

DESCRIPTION OF SYMBOLS 1 Transmission belt 2 Adhesive rubber layer 3 Core wire 4 Cover canvas 5 Stretch rubber layer 6 Compression rubber layer 7 Cog valley part 8 Cog mountain part 11 Upper cog part 12 Lower cog part 13 Reinforcement layer

Claims (5)

  A transmission belt having a compression rubber layer and a stretch rubber layer adjacent to an adhesive rubber layer in which a core wire is embedded, and at least a compression rubber layer having a cog portion in which a cog mountain portion and a cog valley portion are alternately arranged. A reinforcing layer made of a fiber reinforced resin is embedded in the stretched rubber layer or laminated on the surface of the stretched layer, and the fibers constituting the fiber reinforced resin are oriented in the belt width direction. Belt.   The power transmission belt according to claim 1, wherein the fiber constituting the fiber reinforced resin used as the reinforcing layer is carbon fiber.   The power transmission belt according to claim 1, wherein the resin constituting the fiber reinforced resin used as the reinforcing layer is a thermosetting resin.   The power transmission belt according to claim 3, wherein the thermosetting resin constituting the fiber reinforced resin used as the reinforcing layer is an epoxy resin.   The transmission belt according to any one of claims 1 to 4, wherein a cover canvas is not disposed on the stretched rubber layer.

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