JP6951214B2 - Friction transmission belt - Google Patents

Description

The present invention relates to a friction transmission belt having a V-shaped cross section orthogonal to the belt circumferential direction and having friction transmission surfaces on both sides in the belt width direction.

The friction transmission belt, which has a V-shaped cross section and transmits power by friction transmission, is covered with a raw-edge V-belt, which is a rubber layer with exposed friction transmission surfaces on both sides in the width direction of the belt, and the friction transmission surface. There is a Wrapped V-belt covered with cloth, and it is used properly according to the application due to the difference in the surface texture (friction coefficient) of the friction transmission surface. These friction transmission belts are used in a wide range of fields such as automobiles and industrial machines.

Friction transmission belts are used at high loads. Therefore, the friction transmission belt is required to increase the rigidity (side pressure resistance) in the belt width direction in order to prevent buckling deformation (dishes). For example, Patent Documents 1 to 3 propose a friction transmission belt devised to enhance lateral pressure resistance. Patent Document 1 discloses a rubber V-belt in which aramid short fibers are oriented in the belt width direction on a compressed rubber layer. Further, Patent Document 2 discloses a V-belt with a cog in which a horizontal blind cord is embedded in a compressed rubber layer. The horizontal blind cord is obtained by arranging cords such as aramid fibers along the belt width direction at regular intervals in the belt circumferential direction and connecting them with fine threads. Further, Patent Document 3 discloses a cogged V-belt in which at least one reinforcing layer made of a fiber reinforced resin is embedded in a compressed rubber layer. This reinforcing layer contains carbon fibers oriented in the belt width direction.

Tokuhei No. 5-63656 Special Publication No. 59-7859 Japanese Unexamined Patent Publication No. 2010-196889

By the way, for example, in a large agricultural machine or the like, a friction transmission belt having a large cross-sectional area is used. Further, the belt mechanism used for a large compressor, crusher, generator, pump, etc. has similar operating conditions to the belt mechanism of a large agricultural machine, and a large friction transmission belt is used with a high load. In recent years, such a large friction transmission belt used with a particularly high load is required to improve the rigidity in the circumferential direction of the belt in addition to the improvement of the lateral pressure resistance.

However, the friction transmission belts of Patent Documents 1 to 3 described above are small friction transmission belts used for belt-type transmissions of vehicles such as scooters and automobiles or machines for general industry, and are wound around a pulley having a small diameter. The purpose is to ensure high flexibility while increasing lateral pressure resistance because it is hung and run. That is, the friction transmission belts of Patent Documents 1 to 3 aim to secure flexibility rather than rigidity in the belt circumferential direction. Therefore, even if the structure of the friction transmission belt of Patent Documents 1 to 3 is applied to a large friction transmission belt, sufficient rigidity in the belt circumferential direction cannot be obtained.
In addition, Patent Document 3 in which the applicant is the same as the present application describes that the fibers of the reinforcing layer may be oriented in the belt width direction and the belt circumferential direction (longitudinal direction). However, in reality, if the belt is oriented in the circumferential direction, the flexibility, which is a problem of Patent Document 3, cannot be ensured.

Also, small friction transmission belts are often used in biaxial layouts. For example, it corresponds to the case where it is used in a belt type transmission of a scooter. In such a case, the winding angle around the small-diameter pulley becomes large, so that higher flexibility is required.
On the other hand, large friction transmission belts are often used in multi-axis layouts. Therefore, not only the diameter of the pulley is large, but also the winding angle is small, so that a certain degree of flexibility is required, but the flexibility is not as high as that of a small friction transmission belt.

An object of the present invention is to provide a friction transmission belt capable of increasing rigidity in the belt width direction and the belt circumferential direction while suppressing a decrease in flexibility.

Means for Solving Problems and Effects of Invention

The friction transmission belt of the present invention is an annular friction transmission belt having a V-shaped cross section orthogonal to the belt circumferential direction and having friction transmission surfaces on both sides in the belt width direction, and is embedded in a rubber layer and the rubber layer. It has a structure in which the core wire is embedded in the rubber layer on at least one of the inner peripheral side of the belt and the outer peripheral side of the belt, and fiber bundles of high-strength fibers are arranged so as to intersect with each other. It is characterized by comprising a high-strength fiber sheet having a woven structure or a knitted structure.

According to this configuration, the friction transmission belt has a high-strength fiber sheet embedded in a rubber layer on at least one of the inner peripheral side of the core wire and the outer peripheral side of the belt. The high-strength fiber sheet has a structure in which fiber bundles of high-strength fibers are arranged so as to intersect with each other. Therefore, it is possible to increase the rigidity in the belt width direction and the belt circumferential direction while suppressing the decrease in the flexibility of the friction transmission belt.

In the present invention, the V-shaped cross section orthogonal to the belt circumferential direction means that two side surfaces are arranged on two V-shaped straight lines in the cross section orthogonal to the belt circumferential direction. .. The cross section of the friction transmission belt of the present invention orthogonal to the belt circumferential direction may be rectangular, hexagonal, or other as long as it is V-shaped.

In the friction transmission belt of the present invention, the inner peripheral surface of the rubber layer is covered with a cover cloth exposed to the outside, or is exposed to the outside, and the rubber layer is formed from the center of the core wire. The ratio of the length in the belt thickness direction from the center of the core wire to the high-strength fiber sheet is 8% or more and 28% or less with respect to the maximum length in the belt thickness direction to the surface on the inner peripheral side of the belt. It is preferable to have.

According to this configuration, by arranging a flat high-strength fiber sheet near the core wire, it is possible to prevent the pitch line of the core wire from being disturbed during molding and vulcanization of the friction transmission belt, and to improve the uniformity of the core wire. Can be secured. As a result, uniform tension is applied to the core wire when the belt is running, and stable running is possible.

The friction transmission belt of the present invention preferably has a maximum length in the belt width direction of 12 to 70 mm and a belt thickness of 5 to 26 mm.

In the friction transmission belt of the present invention, the high-strength fiber sheet preferably has a tensile strength of 2000 N / mm ² or more in two directions in which the fiber bundles intersect.

In the friction transmission belt of the present invention, the high-strength fiber sheet may be arranged so that the two intersecting directions of the fiber bundles are the belt circumferential direction and the belt width direction.

According to this configuration, the rigidity of the friction transmission belt in the belt width direction and the belt circumferential direction can be further increased.

In the friction transmission belt of the present invention, the high-strength fiber sheet may be arranged so that the two intersecting directions of the fiber bundles are inclined with respect to the belt circumferential direction and the belt width direction.

According to this configuration, the friction transmission belt can have higher flexibility because the fiber bundles of the high-strength fibers are not arranged along the belt circumferential direction.

In the friction transmission belt of the present invention, it is preferable that the high-strength fiber bundle constituting the high-strength fiber sheet contains at least one of an aramid fiber and a carbon fiber.

In the friction transmission belt of the present invention, when the fiber bundle is composed of aramid fibers, the texture amount of the high-strength fiber sheet is 90 to 870 g / m ² , and the fiber bundle is composed of carbon fibers. The texture amount of the high-strength fiber sheet is preferably ^{200 to 300 g / m 2.}

In the friction transmission belt of the present invention, when the fiber bundle is composed of aramid fibers, the thickness of the high-strength fiber sheet is 0.03 to 0.24 mm, and the fiber bundle is composed of carbon fibers. The thickness of the high-strength fiber sheet is preferably 0.05 to 0.09 mm.

In the friction transmission belt of the present invention, the rubber layer is composed of an adhesive rubber layer in which at least a part of the core wire is embedded and a rubber composition different from the adhesive rubber layer, and the inner circumference of the belt of the adhesive rubber layer. The high-strength fiber sheet has a compressed rubber layer provided on the side and an stretch rubber layer provided on the outer peripheral side of the belt of the adhesive rubber layer, which is composed of a rubber composition different from the adhesive rubber layer. It may be embedded in at least one of the rubber layer and the compressed rubber layer and between the adhesive rubber layer and the stretched rubber layer.

According to this configuration, the high-strength fiber sheet is embedded between the adhesive rubber layer and the compressed rubber layer, and at least one between the adhesive rubber layer and the stretch rubber layer. The rubber composition constituting the adhesive rubber layer is different from the rubber composition constituting the compressed rubber layer and the rubber composition constituting the stretched rubber layer. At least a part of the core wire is embedded in the adhesive rubber layer. Therefore, the adhesive rubber layer receives almost no compressive force or tensile force when the belt is used. Therefore, the rubber composition constituting the adhesive rubber layer can have a composition that gives priority to enhancing the adhesiveness to the core wire. Thereby, the adhesiveness between the high-strength fiber sheet and the adhesive rubber layer can be enhanced.

In the friction transmission belt of the present invention, the rubber layer has a compressed rubber layer and the stretched rubber layer which is composed of a rubber composition different from the compressed rubber layer and is provided on the outer peripheral side of the belt of the compressed rubber layer. The core wire is embedded between the compressed rubber layer and the stretched rubber layer in the compressed rubber layer or the stretched rubber layer, and the high-strength fiber sheet is the compressed rubber layer and the stretched rubber layer. It may be embedded in at least one of the rubber layer and between the compressed rubber layer and the stretched rubber layer.

According to this configuration, it is not necessary to provide the adhesive rubber layer, so that the manufacturing process can be simplified.

In the friction transmission belt of the present invention, it is preferable that the high-strength fiber sheet is subjected to an adhesive treatment that enhances the adhesiveness with the rubber layer.

According to this configuration, the adhesiveness between the high-strength fiber sheet and the rubber layer can be enhanced.

It is sectional drawing of the friction transmission belt which concerns on embodiment of this invention. It is a top view of the high-strength fiber sheet. It is a perspective view explaining the manufacturing procedure of a friction transmission belt. It is sectional drawing in the process of manufacturing a friction transmission belt. It is a perspective view explaining another manufacturing procedure of a friction transmission belt. It is a figure explaining the use example of a friction transmission belt. It is a top view of the high-strength fiber sheet of a modified example. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. (A) is a cross-sectional view during manufacturing of the friction transmission belt of the modified example, and (b) is a cross-sectional view of the friction transmission belt. It is a side view of the traveling test machine of a 4-axis layout used in an Example.

Next, an embodiment of the present invention will be described.
The friction transmission belt 1 of the present embodiment is used, for example, in a transmission mechanism of a large agricultural machine, a large compressor, a crusher, a generator, a pump, and the like. However, the friction transmission belt of the present invention can be applied to industrial machines and vehicles other than the above. As shown in FIG. 1, the friction transmission belt 1 is used by being wound around a pulley 100 having a V-shaped groove 101 (hereinafter, referred to as a V groove 101).

The friction transmission belt 1 is annular and is used by being wound around at least two pulleys 100 (drive pulley and driven pulley). In the following description, the belt circumferential direction, the belt width direction, the belt thickness direction, the belt outer peripheral side, and the belt inner peripheral side are the directions shown in FIG. The friction transmission belt 1 has a V-shaped cross section orthogonal to the belt circumferential direction, and is sandwiched between V grooves 101 of the pulley 100 for use. The friction transmission belt 1 has friction transmission surfaces 1a and 1b on both sides in the belt width direction. The friction transmission surfaces 1a and 1b come into contact with the V groove 101 of the pulley 100. Power is transmitted between the friction transmission belt 1 and the pulley 100 by the frictional force due to this contact. The maximum length of the friction transmission belt 1 in the belt width direction is, for example, 12 to 70 mm. Considering the effect of the friction transmission belt 1 described later, 20 to 70 mm is more effective, and 30 to 70 mm is further effective. The belt thickness of the friction transmission belt 1 is, for example, 5 to 26 mm. Considering the effect described later of the friction transmission belt 1, 11 to 26 mm is more effective, and 18 to 26 mm is further effective.

The friction transmission belt 1 is a wrapped V-belt, and has a belt main body 2 and a cover cloth 3 that covers the entire circumference of the belt main body 2. The cover cloth 3 is exposed to the outside. The cover cloth 3 is a woven cloth woven with warp and weft made of synthetic fibers such as polyester, polyamide, aramid, and vinylon, and natural fibers such as cotton. The belt body 2 has a rubber layer 4, a core wire 5 embedded in the rubber layer 4, and two high-strength fiber sheets 6 embedded in the rubber layer 4. The rubber layer 4 has an adhesive rubber layer 7 in which a core wire 5 is embedded, a compression rubber layer 8, and an stretch rubber layer 9. The compression rubber layer 8 is provided on the inner peripheral side of the belt of the adhesive rubber layer 7. The compressed rubber layer 8 is compressed in the circumferential direction of the belt when it is wound around the pulley 100 and traveled. The stretch rubber layer 9 is provided on the outer peripheral side of the belt of the adhesive rubber layer 7. The stretch rubber layer 9 is stretched in the circumferential direction of the belt when it is wound around the pulley 100 and traveled. The thickness of the compressed rubber layer 8 is larger than the thickness of the stretched rubber layer 9. The two high-strength fiber sheets 6 are provided between the adhesive rubber layer 7 and the compressed rubber layer 8 and between the adhesive rubber layer 7 and the stretch rubber layer 9, respectively.

The adhesive rubber layer 7, the compressed rubber layer 8, and the stretched rubber layer 9 are composed of a rubber composition. The rubber composition constituting the adhesive rubber layer 7 is different from the rubber composition constituting the compressed rubber layer 8 and the rubber composition constituting the stretched rubber layer 9. The rubber composition constituting the adhesive rubber layer 7 has better adhesiveness to the core wire 5 and the high-strength fiber sheet 6 than the rubber composition constituting the compressed rubber layer 8 and the rubber composition constituting the stretched rubber layer 9. high. The rubber composition constituting the stretched rubber layer 9 and the rubber composition constituting the compressed rubber layer 8 may be the same or different.

As the rubber component of the rubber composition, vulcanized or crosslinkable rubber is used. Specifically, for example, diene rubber (natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber, acrylonitrile butadiene rubber, hydride nitrile rubber, etc.), ethylene-α-olefin elastomer, chlorosulphonized polyethylene rubber, etc. , Alkylated chlorosulphonized polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluorinated rubber and the like. These rubber components can be used alone or in combination of two or more.

Vulcanization agents or cross-linking agents, co-cross-linking agents, vulcanization aids, vulcanization accelerators, vulcanization retarders, metal oxides (zinc oxide, magnesium oxide, calcium oxide, etc.) may be added to the rubber composition, if necessary. Barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide, etc.), enhancer (carbon black, silicon oxide such as hydrous silica, etc.), short fibers, filler (clay, calcium carbonate, talc, mica, etc.), softening Agents (oils such as paraffin oil and naphthenic oil), processing agents or processing aids (stearic acid, metal stearate, wax, paraffin, etc.), antioxidants (antioxidants, heat antiaging agents, bending Crack inhibitor, ozone deterioration inhibitor, etc.), colorant, tackifier, plasticizer, coupling agent (silane coupling agent, etc.), stabilizer (ultraviolet absorber, heat stabilizer, etc.), flame retardant, antistatic Agents and the like may be blended. The metal oxide may be blended as a cross-linking agent.

The rubber composition constituting the stretched rubber layer 9 and the compressed rubber layer 8 may contain short fibers. The rubber composition constituting the adhesive rubber layer 7 does not contain short fibers.

The core wire 5 extends in the circumferential direction of the belt and is embedded at regular intervals in the width direction of the belt. The core wire 5 is composed of a twisted cord (various twists, single twists, rank twists, etc.) using a multifilament yarn. The material of the core wire 5 is, for example, a synthetic fiber such as an aramid fiber or an inorganic fiber such as a carbon fiber. The core wire 5 may be subjected to an adhesive treatment with an RFL liquid or the like for the purpose of enhancing the adhesiveness with the adhesive rubber layer 7.

The two high-strength fiber sheets 6 are each embedded at positions close to the core wire 5 of the rubber layer 4. Let L1 be the maximum length in the belt thickness direction from the center of the core wire 5 to the surface of the rubber layer 4 on the inner peripheral side of the belt. Let L2a be the length in the belt thickness direction from the center of the core wire 5 to the high-strength fiber sheet 6 on the inner peripheral side of the belt. Let L2b be the length in the belt thickness direction from the center of the core wire 5 to the high-strength fiber sheet 6 on the outer peripheral side of the belt. The lengths L2a and L2b of the two high-strength fiber sheets 6 may be the same or different. The ratio of the length L2a to the length L1 is preferably 8% or more and 28% or less. The ratio of the length L2b to the length L1 is preferably 8% or more and 28% or less.

As shown in FIG. 2, the high-strength fiber sheet 6 is woven with a plurality of first fiber bundles 6a and a plurality of second fiber bundles 6b orthogonal to the first fiber bundle 6a. In the high-strength fiber sheet 6, the first fiber bundle 6a is along the belt circumferential direction. The second fiber bundle 6b is along the belt width direction. The direction of the first fiber bundle 6a does not have to be exactly parallel to the belt circumferential direction. The first fiber bundle 6a may be tilted by about 2 ° with respect to the belt circumferential direction. Further, the second fiber bundle 6b may be inclined by about 2 ° with respect to the belt width direction. In the present invention, the two directions of the fiber bundle, the belt circumferential direction and the belt width direction, include the case where the fiber bundle is inclined by about 2 ° with respect to the belt circumferential direction and the belt width direction, respectively.

The fiber bundle is composed of high-strength fibers such as aramid fibers and carbon fibers. The fibers constituting the first fiber bundle 6a and the second fiber bundle 6b may be the same or different. Each fiber bundle has a structure in which a plurality of filaments (long fibers) are aligned. The tensile strength of the high-strength fiber sheet 6 in the orientation direction of the first fiber bundle 6a and the orientation direction of the second fiber bundle 6b is preferably ^{2000 N / mm 2 or more, for example.} When both the first fiber bundle 6a and the second fiber bundle 6b are composed of aramid fibers, for example, it is 2060 N / mm ² or more, and both the first fiber bundle 6a and the second fiber bundle 6b are composed of carbon fibers. In this case, for example, it is 2900 N / mm ² or more. The amount of the high-strength fiber sheet 6 is, for example, 90 to 870 g / m ² when both the first fiber bundle 6a and the second fiber bundle 6b are composed of aramid fibers, and the first fiber bundle 6a and the second fiber bundle 6a and the second fiber bundle 6a. When both of the fiber bundles 6b are composed of carbon fibers, it is, for example, 200 to 300 g / m ² . The thickness of the high-strength fiber sheet 6 is, for example, 0.03 to 0.24 mm when both the first fiber bundle 6a and the second fiber bundle 6b are composed of aramid fibers, and the first fiber bundle 6a and the first fiber bundle 6a have a thickness of 0.03 to 0.24 mm. When both of the two fiber bundles 6b are composed of carbon fibers, it is, for example, 0.05 to 0.09 mm.

The high-strength fiber sheet 6 may be subjected to an adhesive treatment for enhancing the adhesiveness with the surrounding rubber layer 4 (adhesive rubber layer 7). The adhesive treatment may be an RFL treatment in which the fibers constituting the high-strength fiber sheet 6 or the high-strength fiber sheet 6 are immersed in an RFL liquid, or an impregnated resin treatment in which the fibers are immersed in a resin solution. The RFL solution is a mixture of an initial condensate of resorcin and formalin into latex, and the latex used here includes styrene-butadiene-pyridine ternary copolymer, hydrogenated nitrile rubber, chlorosulphonized polyethylene, and epichlorohydrin. Such as latex. The resin solution used for the impregnating resin treatment is, for example, an isocyanate solution or an epoxy solution. After the impregnated resin treatment, an adhesion treatment using an RFL liquid treatment may be performed. Further, as an adhesive treatment, an unvulcanized rubber composition dissolved in a solvent to form a rubber paste is applied to the surface of the high-strength fiber sheet 6, and then the solvent is evaporated to the surface of the high-strength fiber sheet 6. A rubber glue treatment for forming a film of the unvulcanized rubber composition may be performed. Further, a rubber glue treatment may be performed after the adhesion treatment using the RFL liquid.

Next, the manufacturing procedure of the friction transmission belt 1 will be described with reference to FIGS. 3 and 4.
First, as shown in FIG. 3, the unvulcanized rubber sheet 119 constituting the stretch rubber layer 9 is wound around the columnar molding drum 110. Next, a long strip 116 of the high-strength fiber sheet 6 is prepared. The high-strength fiber sheet 6 may be subjected to an adhesive treatment such as a known RFL treatment, an impregnated resin treatment, or a rubber glue treatment in order to enhance the adhesive strength with the surrounding rubber layer. The width of the strip 116 is smaller than the total width of the sleeve (cylindrical body) formed of the unvulcanized rubber sheet 119. The width of the strip 116 may be larger or smaller than the belt width of the friction transmission belt 1. The direction of the first fiber bundle 6a or the second fiber bundle 6b coincides with the longitudinal direction of the strip 116. The strip 116 is spirally wound at the same pitch as the width of the strip 116. That is, the adjacent strips 116 are wound so as not to overlap. Subsequently, the unvulcanized rubber sheet 117A (see FIG. 4) forming a part of the adhesive rubber layer 7 is wound around. After that, one core wire 5 is spirally wound. Alternatively, a plurality of core wires 5 are wound at predetermined intervals. Next, the unvulcanized rubber sheet 117B (see FIG. 4) constituting the remaining portion of the adhesive rubber layer 7 is wound, and then the strip-shaped body 116 of the high-strength fiber sheet 6 is wound in the same manner as before. Then, as shown in FIG. 4, the unvulcanized rubber sheet 118 (see FIG. 4) constituting the compressed rubber layer 8 is wound around the unvulcanized rubber sheet 118 to form the unvulcanized belt sleeve.

Next, the unvulcanized belt sleeve is cut to a predetermined width and cut so that the cross section has a V shape, and the belt body 2 in the unvulcanized state is processed. After that, the belt body 2 is covered with the friction-treated cover cloth 3 to form an unvulcanized belt. Then, the unvulcanized belt is fitted into the molding die and heated and pressed to vulcanize (or crosslink). As a result, the friction transmission belt 1 is formed. In the friction treatment, a calendar roll is used, and the unvulcanized rubber composition and the cover cloth 3 are simultaneously passed between the rolls rotating at different surface speeds, so that the unvulcanized rubber composition is passed between the fibers of the cover cloth 3 at the same time. This is a process of rubbing the rubber composition.

In the above manufacturing procedure, the components on the outer peripheral side of the friction transmission belt 1 are wound around the molding drum 110 in order, but the components on the inner peripheral side of the friction transmission belt 1 may be wound around the molding die in order. .. However, since the thickness of the compressed rubber layer 8 is larger than the thickness of the stretched rubber layer 9, from the viewpoint of preventing the misalignment of the high-strength fiber sheet 6 and the core wire 5, the components on the outer peripheral side of the friction transmission belt 1 are ordered in order. It is preferable to wind it around the molding drum 110.

Further, in the above manufacturing procedure, the strip 116 of the high-strength fiber sheet 6 is spirally wound, but as shown in FIG. 5, the width is the same as the total width of the sleeve formed of the unvulcanized rubber sheet 119. The high-strength fiber sheet 6 to be held may be wound.

According to the friction transmission belt 1 of the present embodiment, the following effects can be obtained.
The friction transmission belt 1 has a high-strength fiber sheet 6 embedded in the rubber layer 4 on the inner peripheral side of the belt and the outer peripheral side of the belt of the core wire 5. The high-strength fiber sheet 6 has a structure in which fiber bundles 6a and 6b of high-strength fibers are arranged so as to intersect with each other. Therefore, it is possible to increase the rigidity in the belt width direction and the belt circumferential direction while suppressing the decrease in the flexibility of the friction transmission belt 1.

By increasing the rigidity (side pressure resistance) in the belt width direction, it is possible to prevent the friction transmission belt 1 from buckling and deforming so as to fall into the V groove 101 even when used under a high load. When buckling deformation occurs, shear stress is generated inside the belt. In particular, shear stress tends to concentrate on interfaces with different mechanical properties, causing interfacial delamination. In the present embodiment, by preventing buckling deformation, interfacial peeling due to shear stress can be suppressed.

FIG. 6A is an example of a power transmission device in which the tension pulley 103 is configured to be movable over a position where tension is applied to the friction transmission belt 1 and a position where tension is not applied. When the tension pulley 103 applies tension to the friction transmission belt, the friction transmission belt 1 transmits power, and when the tension pulley 103 does not apply tension to the friction transmission belt 1, the friction transmission belt 1 transmits power. do not. The position of the tension pulley 103 is switched in a state where the drive pulley is rotated. Therefore, when tension is applied by the tension pulley 103, the friction transmission belt 1 receives a strong impact. When a conventional friction transmission belt having low rigidity in the belt circumferential direction is used for such a power transmission device, the friction transmission belt may break at an early stage. On the other hand, since the friction transmission belt 1 of the present embodiment has high rigidity in the belt circumferential direction, the impact force can be dispersed even if a strong impact is received, and the durability can be improved.

Further, for example, as shown in FIG. 6B, when the distance between the pulleys 100 is long, if a conventional friction transmission belt is used, the belt runout tends to increase during belt running. As a result, the belt may come off the pulley 100 or turn over on the pulley 100, and the transmission function may be stopped. On the other hand, in the friction transmission belt 1 of the present embodiment, the circumference of the core wire 5 is reinforced by the high-strength fiber sheet 6 having a structure in which the fiber bundles 6a and 6b of the high-strength fibers intersect, so that the runout during running is small. Become. The smaller the runout, the less risk the belt will come off the pulley 100 or tip over on the pulley 100.

Further, since the runout during running is reduced and the stability during running is improved, when a plurality of friction transmission belts 1 are wound around a pulley 100 having a plurality of V grooves 101 arranged in the direction of the rotation axis. , It is possible to prevent adjacent belts from interfering with each other due to runout.

Further, the length in the belt thickness direction from the center of the core wire 5 to the high-strength fiber sheet 6 with respect to the length L1 in the belt thickness direction from the center of the core wire 5 to the surface on the inner peripheral side of the belt of the rubber layer 4. When the ratio of L1 is 8% or more and 28% or less, the flat high-strength fiber sheet 6 is arranged near the core wire 5. As a result, it is possible to prevent the pitch line of the core wire 5 from being disturbed during molding and vulcanization of the friction transmission belt 1, and it is possible to ensure the uniformity of the core wire 5. As a result, uniform tension is applied to the core wire when the belt is running, and stable running is possible.

The high-strength fiber sheet 6 of the present embodiment is arranged so that the two intersecting directions of the fiber bundles 6a and 6b are the belt circumferential direction and the belt width direction. Therefore, the rigidity of the friction transmission belt 1 in the belt width direction and the belt circumferential direction can be further increased.

Further, in the present embodiment, the high-strength fiber sheet 6 is embedded between the adhesive rubber layer 7 and the compressed rubber layer 8 and between the adhesive rubber layer 7 and the stretch rubber layer 9. The rubber composition constituting the adhesive rubber layer 7 is different from the rubber composition constituting the compressed rubber layer 8 and the rubber composition constituting the stretched rubber layer 9. At least a part of the core wire 5 is embedded in the adhesive rubber layer 7. Therefore, the adhesive rubber layer 7 receives almost no compressive force or tensile force when the belt is used. Therefore, the rubber composition constituting the adhesive rubber layer 7 can have a composition that gives priority to enhancing the adhesiveness to the core wire 5. Thereby, the adhesiveness between the high-strength fiber sheet 6 and the adhesive rubber layer 7 can be enhanced.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims.

The friction transmission belt 1 may be a low-edge V belt in which the friction transmission surfaces 1a and 1b are not covered with the cover cloth 3. The cover cloth 3 may not be provided at all, and may cover at least one of the outer peripheral surface and the inner peripheral surface of the belt body 2. That is, the surface of the rubber layer 4 on the inner peripheral side of the belt does not have to be covered with the cover cloth 3 exposed to the outside.

The friction transmission belt 1 of the present invention may be a cog belt having a plurality of cogs arranged in the belt circumferential direction on at least one of the inner peripheral surface of the belt and the outer peripheral surface of the belt. In this case, the high-strength fiber sheet 6 is embedded along the core wire 5 without following the unevenness of the cog. When there is a cog on the inner peripheral surface of the belt, the "maximum length in the belt thickness direction from the center of the core wire to the inner peripheral surface of the belt of the rubber layer" in the present invention is the tip (convex) of the cog from the center of the core wire. The length in the belt thickness direction up to the tip of the belt.

In the above embodiment, in the high-strength fiber sheet 6, the first fiber bundle 6a and the second fiber bundle 6b that are orthogonal to each other are arranged along the belt circumferential direction and the belt width direction. , The first fiber bundle 6a and the second fiber bundle 6b that are orthogonal to each other may be arranged so as to be inclined with respect to the belt circumferential direction and the belt width direction. For example, in the high-strength fiber sheet 6, the first fiber bundle 6a and the second fiber bundle 6b may be arranged so as to be inclined by 45 ° with respect to the belt circumferential direction. According to this configuration, the friction transmission belt 1 can have higher flexibility because the fiber bundles of the high-strength fibers are not arranged along the belt circumferential direction. The directions of the fiber bundles 6a and 6b of the two high-strength fiber sheets 6 may be the same or different.

In the above embodiment, the high-strength fiber sheet 6 is arranged in only one layer on the inner peripheral side of the belt of the core wire 5, but may be arranged in two or more layers. In the above embodiment, the high-strength fiber sheet 6 is arranged in only one layer on the outer peripheral side of the belt of the core wire 5, but may be arranged in two or more layers. When two or more layers of the high-strength fiber sheets 6 are stacked, it is preferable that the ratio of the lengths L2a and L2b to the length L1 is 8% or more and 28% or less for each high-strength fiber sheet 6. When two or more layers of the high-strength fiber sheets 6 are stacked, a rubber layer may be interposed between the high-strength fiber sheets 6. When the friction transmission belt of this modified example is manufactured using the strip-shaped body 106 of the high-strength fiber sheet 6 (see FIG. 3), it is spirally wound at a pitch of the width of the strip-shaped body 106, and then another strip-shaped body is formed from above. The body 106 is spirally wound at a pitch of the width of the strip 106. At this time, the ends of the strip 106 are prevented from overlapping. Thereby, the misalignment of the band-shaped body 106 can be prevented.

The high-strength fiber sheet 6 of the above embodiment is woven with fiber bundles arranged so as to be orthogonal to each other, but the high-strength fiber sheet of the present invention is woven with fiber bundles intersecting at angles other than right angles. May be good.

The high-strength fiber sheet of the present invention may be knitted by fiber bundles of high-strength fibers so that the fiber bundles of high-strength fibers intersect. The angle at which the fiber bundles intersect may or may not be a right angle.

In the high-strength fiber sheet of the present invention, for example, as in the high-strength fiber sheet 206 shown in FIG. 7A, the fiber bundles 206a and 206b of the high-strength fibers are arranged so as to intersect (orthogonally in FIG. 7A). The fibers may be woven by the fiber bundles 206a and 206b and the auxiliary threads 206c and 206d so as to have the structure.
The plurality of first fiber bundles 206a are arranged as a whole on the back surface of the plurality of second fiber bundles 206b in the drawing. The first auxiliary thread 206c is arranged between the first fiber bundles 206a in parallel with the first fiber bundles 206a. The second auxiliary thread 206d is arranged between the second fiber bundles 206b in parallel with the second fiber bundle 206b. The first auxiliary thread 206c and the second auxiliary thread 206d hold the first fiber bundle 206a and the second fiber bundle 206b in an intersecting state. The auxiliary threads 206c and 206d are, for example, multifilament threads. The auxiliary yarn is made of high-strength fibers. The first auxiliary thread 206c and the second auxiliary thread 206d may be formed of the same fiber or may be formed of different fibers. The auxiliary threads 206c and 206d may be formed of the same fibers as at least one of the first fiber bundle 206a and the second fiber bundle 206b, or may be formed of fibers different from the fiber bundles 206a and 206b.

In the high-strength fiber sheet of the present invention, for example, as in the high-strength fiber sheet 306 shown in FIG. 7 (b), the fiber bundles 306a and 306b of the high-strength fibers are arranged so as to intersect (orthogonally in FIG. 7 (b)). It may have a structure and a knitting structure.
The plurality of first fiber bundles 306a are arranged as a whole on the back surface of the plurality of second fiber bundles 306b in the drawing. The high-strength fiber sheet 306 has a first auxiliary thread 306c and a second auxiliary thread 306d. The first auxiliary yarn 306c and the second auxiliary yarn 306d are knitted through between the first fiber bundle 306a and the second fiber bundle 306b. The first auxiliary thread 306c and the second auxiliary thread 306d hold the first fiber bundle 306a and the second fiber bundle 306b in an intersecting state. The auxiliary threads 306c and 306d are, for example, multifilament threads. The auxiliary threads 306c and 306d are made of high-strength fibers. The first auxiliary thread 306c and the second auxiliary thread 306d may be formed of the same fiber or may be formed of different fibers. The auxiliary threads 306c and 306d may be formed of the same fibers as at least one of the first fiber bundle 306a and the second fiber bundle 306b, or may be formed of fibers different from the fiber bundles 306a and 306b.

In the above embodiment, the high-strength fiber sheet 6 is embedded between the adhesive rubber layer 7 and the compressed rubber layer 8 and between the adhesive rubber layer 7 and the stretch rubber layer 9. However, for example, as in the friction transmission belt 201 shown in FIG. 8B, the high-strength fiber sheet 6 may be embedded only between the adhesive rubber layer 7 and the compression rubber layer 8. FIG. 8A shows a state in which a component of the belt body is wound around the forming drum 110 in the manufacturing process of the friction transmission belt 201. Further, although not shown, the high-strength fiber sheet 6 may be embedded only between the adhesive rubber layer 7 and the stretch rubber layer 9.

When the high-strength fiber sheet 6 is embedded only between the adhesive rubber layer 7 and the compressed rubber layer 8 and between the adhesive rubber layer 7 and the stretch rubber layer 9, the core wire 5 is entirely It does not have to be embedded in the adhesive rubber layer 7.
For example, when the high-strength fiber sheet 6 is embedded only between the adhesive rubber layer 307 and the compressed rubber layer 8 as in the friction transmission belt 301 shown in FIG. 9B, the core wire 5 is the adhesive rubber layer. It may be embedded between 307 and the stretch rubber layer 309. FIG. 9A shows a state in which the components of the belt body are wound around the forming drum 110 in the manufacturing process of the friction transmission belt 301. The core wire 5 is arranged between the rubber sheet 319 forming the stretch rubber layer 309 and the rubber sheet 317 forming the adhesive rubber layer 307.
Further, although not shown, when the high-strength fiber sheet 6 is embedded only between the adhesive rubber layer 7 and the stretch rubber layer 9, the core wire 5 is the adhesive rubber layer 7 and the compressed rubber layer 8. It may be buried in between.

In the above embodiment, the rubber layer 4 has the adhesive rubber layer 7 between the compressed rubber layer 8 and the stretched rubber layer 9, but the adhesive rubber layer 7 may not be provided.
For example, as in the friction transmission belt 401 shown in FIG. 10B, the core wire 5 is embedded between the compression rubber layer 408 and the stretch rubber layer 409, and the two high-strength fiber sheets 6 are formed by the compression rubber layer. It may be embedded in 408 and the stretch rubber layer 409, respectively. FIG. 10A shows a state in which a component of the belt body is wound around the forming drum 110 in the manufacturing process of the friction transmission belt 401. The compressed rubber layer 408 is formed by two rubber sheets 418A and 418B arranged on both sides of one high-strength fiber sheet 6. The stretch rubber layer 409 is formed by two rubber sheets 419A and 419B arranged on both sides of the other high-strength fiber sheet 6.
Further, one of the two high-strength fiber sheets 6 of the friction transmission belt 401 shown in FIG. 10A may not be provided. The friction transmission belt 501 of FIG. 11B is provided with the high-strength fiber sheet 6 embedded in the stretch rubber layer 409 of the two high-strength fiber sheets 6 of the friction transmission belt 401 shown in FIG. 10A. Indicates the case where there is no. FIG. 11A shows a state in which a component of the belt body is wound around the forming drum 110 in the manufacturing process of the friction transmission belt 501. The stretch rubber layer 509 of the friction transmission belt 501 is formed by one rubber sheet 519. Although not shown, the high-strength fiber sheet 6 embedded in the compression rubber layer 408 may not be provided among the two high-strength fiber sheets 6 of the friction transmission belt 401 shown in FIG. 10 (a). ..
Further, for example, as in the friction transmission belt 601 shown in FIG. 12B, one of the core wire 5 and the two high-strength fiber sheets 6 is embedded in the compressed rubber layer 608, and the other high-strength fiber sheet 6 is formed. , May be embedded between the compressed rubber layer 608 and the stretched rubber layer 9. FIG. 12A shows a state in which the components of the belt body are wound around the forming drum 110 in the manufacturing process of the friction transmission belt 601. The compressed rubber layer 608 is formed by three rubber sheets 618A, 618B, and 618C. Although not shown, one of the core wire 5 and the two high-strength fiber sheets 6 is embedded in the stretch rubber layer 9, and the other high-strength fiber sheet 6 is the compressed rubber layer 8 and the stretch rubber layer 9. It may be buried between and.
Further, for example, as in the friction transmission belt 701 shown in FIG. 13B, only one high-strength fiber sheet 6 is provided, the core wire 5 is embedded in the compressed rubber layer 708, and the high-strength fiber sheet 6 is formed. , May be embedded between the compressed rubber layer 708 and the stretched rubber layer 9. FIG. 13A shows a state in which a component of the belt body is wound around the forming drum 110 in the manufacturing process of the friction transmission belt 701. The compressed rubber layer 708 is formed by two rubber sheets 718A and 718B arranged on both sides of the core wire 5. Although not shown, the high-strength fiber sheet 6 has only one high-strength fiber sheet 6, the core wire 5 is embedded in the stretch rubber layer 9, and the high-strength fiber sheet 6 has the compressed rubber layer 8 and the stretch rubber layer 9. It may be buried between and.

When the adhesive rubber layer is not provided, if the high-strength fiber sheet 6 is subjected to an adhesive treatment such as RFL treatment, impregnation resin treatment, or rubber glue treatment in the manufacturing process, the high-strength fiber sheet 6 and the core wire 5 are connected. It is not necessary to interpose a rubber sheet between them. The friction transmission belt 801 shown in FIG. 14A is an example. As shown in FIG. 14B, the belt body of the friction transmission belt 801 is a rubber sheet 819 forming the stretch rubber layer 809, a core wire 5, a high-strength fiber sheet 6, and a rubber sheet 118 forming the compressed rubber layer 8. And are formed by winding them around the molding drum 110 in order.

Hereinafter, specific examples 1 to 14 of the present invention will be described.
In the friction transmission belts of Examples 1 and 8, similar to the friction transmission belt 1 of the above embodiment shown in FIG. 1, high-strength fiber sheets are arranged on both sides of the core wire. In the friction transmission belts of Examples 2 to 7 and 9 to 14, a high-strength fiber sheet was arranged only on the inner peripheral side of the belt of the core wire, similarly to the friction transmission belt 201 shown in FIG. Table 1 shows the ratio of the length L2a to the length L1 of the friction transmission belt of each embodiment and the ratio of the length L2b to the length L1. The definitions of the lengths L1, L2a, and L2b are as described in the above embodiment. The friction transmission belts of Examples 1 to 8 and 11 to 14 were JIS K 6323 standard D type having a belt width of 31.5 mm and a belt thickness of 19.0 mm. The friction transmission belt of Example 9 was a JIS K 6323 standard C type having a belt width of 22.0 mm and a belt thickness of 14.0 mm. The friction transmission belt of Example 10 was a JIS K 6323 standard E type having a belt width of 38.0 mm and a belt thickness of 25.0 mm. The circumference of the friction transmission belt of Example 1 was 90 inches. The circumference of the friction transmission belt of Examples 2 to 14 was 210 inches.

As shown in Table 1, as the high-strength fiber sheets, aramid sheets 1 to 3 were used in Examples 1 to 12, and carbon sheets 1 and 2 were used in Examples 13 and 14. Table 2 shows the configurations of the aramid sheets 1 to 3 and the carbon sheets 1 and 2.

The materials of the friction transmission belts of Examples 1 to 14 other than the high-strength fiber sheet were the same. The composition of the compressed rubber layer and the stretched rubber layer is shown in Table 3. The composition of the adhesive rubber layer is shown in Table 2. As the core wire, a twisted cord of polyester fiber having an average wire diameter of 1.985 mm was used. The cover cloth was a plain weave cotton cloth woven with a warp yarn having a fineness of 20 count and a weft yarn having a fineness of 20 count. The yarn densities of the warp and weft of the cover cloth were 75 threads / 50 mm, and the basis weight was 280 g / m ² . The cover cloth was subjected to friction treatment using an unvulcanized rubber sheet having the composition shown in Table 3.

The details of each component in Tables 3 to 5 are as follows.
-Chloroprene rubber: "PM-40" manufactured by DENKA Co., Ltd.
-Magnesium oxide: "Kyowa Mag 30" manufactured by Kyowa Chemical Industry Co., Ltd.
・ Stearic acid: "Stearic acid camellia" manufactured by NOF CORPORATION
・ Anti-aging agent: "Non-flex OD-3" manufactured by Seiko Chemical Co., Ltd.
-Carbon black: "Seast 3" manufactured by Tokai Carbon Co., Ltd.
-Plasticizer: "RS-700" manufactured by ADEKA Corporation
-Vulcanization accelerator: "Noxeller TT" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
-Zinc oxide: "Zinc oxide 3 types" manufactured by Shodo Chemical Industry Co., Ltd.

Table 6 shows the configurations of the friction transmission belts of Comparative Examples 1 to 5. The friction transmission belt of Comparative Example 1 has the same configuration as that of Example 1 except that it does not have a high-strength fiber sheet. The friction transmission belt of Comparative Example 2 had the same configuration as that of Examples 2 to 8 and 11 to 14 except that it did not have a high-strength fiber sheet. The friction transmission belt of Comparative Example 3 had the same configuration as that of Examples 2 to 8 and 11 to 14, except that blind woven fabrics were arranged on both sides of the core wire. The friction transmission belt of Comparative Example 4 had the same configuration as that of Example 9 except that it was arranged on the blind woven fabric on both sides of the core wire. The friction transmission belt of Comparative Example 5 had the same configuration as that of Example 10 except that it was arranged on the blind woven fabric on both sides of the core wire.

The blind woven fabrics used in Comparative Examples 3 to 5 are plain weaves of 1500 denier Tetron (registered trademark) warp yarns and 20th cotton yarn weft yarns so that the weft yarns are closely spaced. The warp yarn had an upper twist number of 14.8 times / 10 cm and a lower twist number of 22.2 times / 10 cm. The density of the warp was 57/5 cm, and the density of the weft was 4/5 cm. In Comparative Examples 3 to 5, the blind woven fabrics were arranged so that the warp threads were arranged along the belt width direction.

<2-axis layout durability test>
The friction transmission belts of Example 1 and Comparative Example 1 were subjected to durability tests using a traveling tester having a two-axis layout. The diameter of the outer peripheral end of the V-groove of the drive pulley and the driven pulley of the traveling tester having a two-axis layout was 345 mm. A friction transmission belt was wound around the two pulleys, and the driven pulley was run for 1 hour with an axial load of 360 kg and a drive pulley load of 20 ps. After that, the shaft load of the driven pulley was changed to 500 kg and the load of the drive pulley was changed to 75 ps, and then the vehicle was run for 1 hour. The rotation speed of the drive pulley was approximately 1800 rpm. Pulleys at the time when the above-mentioned axial load is applied before traveling (initial state), when traveling for 1 hour from the initial state, when the axial load is changed, and when traveling for 1 hour with the axial load changed, respectively. The POC (Pulley Outside Circumference) and BOC (Belt Outside Circumference) of the friction transmission belt wound around the belt were measured. The POC is the belt circumference on the line at the outer peripheral end of the pulley. BOC is the outer peripheral length of the belt (peripheral length of the outer peripheral surface). Table 7 shows the growth rates of POC and BOC at each time point compared to the initial state. Table 7 shows the shaft load at the time when the shaft load was changed and the shaft load measured after the running test. In addition, the rotation speeds of the drive pulley and the driven pulley at the time of traveling for 1 hour from the initial state were measured, and the slip ratio was calculated by comparing with the rotation speed immediately after the start of travel. In addition, the tensile strength of the belt before running and the tensile strength of the belt after the running test were measured, and the strength holding ratio was calculated. The strong retention rate is the ratio of the strongness after the running test to the strongness before running. In addition, after the running test, the appearance of the friction transmission belt was visually confirmed. The results are also shown in Table 7.

As a result of the test, the friction transmission belt of Example 1 had a small drop of the pulley into the V-groove and a small buckling deformation. That is, the flexibility was good. Further, as shown in Table 7, it can be seen that the friction transmission belt of Example 1 has a higher strong holding ratio and higher rigidity in the belt circumferential direction than that of Comparative Example 1. Further, it can be seen that the friction transmission belt of Example 1 has a smaller reduction in axial load than that of Comparative Example 1, so that the reduction in tension is small. Further, it can be seen that the friction transmission belt of Example 1 has a lower slip ratio and is excellent in running stability as compared with Comparative Example 1.

<4-axis layout durability test>
The friction transmission belts of Examples 2 to 14 and Comparative Examples 2 to 5 were subjected to durability tests using a traveling tester having a 4-axis layout shown in FIG. The 4-axis layout traveling tester has a drive pulley Dr, a first driven pulley Dn1, a second driven pulley Dn2, and a tension pulley Ten. The diameter of the outer peripheral end of the V groove of the drive pulley (Dr) and the first driven pulley (Dn1) was 345 mm. The diameter of the outer peripheral end of the V groove of the second driven pulley (Dn2) was 229 mm. The diameter of the outer peripheral end of the V-groove of the tension pulley (Ten) was 200 mm. The number of friction transmission belts that can be wound around the four pulleys at one time is one. In the case of Examples 2 to 8 and 11 to 14 and Comparative Examples 2 and 3 in which the belt type is D type, the belt type was run with an axial load of 500 kg of the first driven pulley Dn1 and a load of 40 ps of the drive pulley Dr. In the case of Example 9 and Comparative Example 4 in which the belt type is C type, the belt type was run with an axial load of 330 kg for the first driven pulley Dn1 and a load of 26 ps for the drive pulley Dr. When the belt type was E type in Example 10 and Comparative Example 5, the belt type was run with an axial load of 750 kg of the first driven pulley Dn1 and a load of 60 ps of the drive pulley Dr. The rotation speed of the drive pulley was set to 875 rpm.

After running for 120 hours under the above conditions, the tensile strength of the belt was measured. In addition, the tensile strength of the belt was measured in advance before running, and the strength retention rate was calculated. The strong retention rate is the ratio of the strongness after the running test to the strongness before running. In addition, using a belt different from the belt used in the test for measuring the strong retention rate, the belt was run until it was damaged, and the running time (life time) was measured. Two tests were carried out for each of Examples 2 to 14 and Comparative Examples 2 to 5, and the average value of the strong retention rate and the average value of the life time after running for 120 hours were calculated. Table 8 shows the average value of the strong retention rate, the average value of the life time, and the belt breakage phenomenon of Examples 2 to 8 and 11 to 14 in which the belt type is D type and Comparative Examples 2 and 3 after running for 120 hours. Table 9 shows the average value of the strong retention rate, the average value of the life time, and the belt breakage phenomenon after running for 120 hours in Example 9 and Comparative Example 4 in which the belt type is C type. Table 10 shows the average value of the strong retention rate, the average value of the life time, and the belt breakage phenomenon after running for 120 hours in Example 10 and Comparative Example 5 in which the belt type is E type.

Comparing the test results of Examples 2 to 8 and 11 to 14 having a belt type of D type and Comparative Examples 2 and 3, the life times of Examples 2 to 8 and 11 to 14 are the life times of Comparative Examples 2 and 3. It was about twice as much as. In particular, the life time of Example 8 in which the high-strength fiber sheets were provided on both sides of the core wire was three times or more the life time of Comparative Examples 2 and 3. The breakage phenomenon of Comparative Examples 2 and 3 is the interfacial peeling between the core wire and the rubber layer, whereas the breakage phenomenon of Examples 2 to 8 and 11 to 14 is compression due to bending fatigue after long-time running. It was a crack in the rubber layer. By providing the high-strength fiber sheet, the friction transmission belts of Examples 2 to 8 and 11 to 14 can be prevented from buckling and deforming so as to fall into the V-groove of the pulley, whereby interfacial peeling due to shear stress can be prevented. It is considered that the life was extended because it was possible to suppress the problem.
In addition, Examples 2 to 8 and 11 to 14 had a higher strong retention rate after running for 120 hours than Comparative Examples 2 and 3.
Therefore, the friction transmission belts of Examples 2 to 8 and 11 to 14 are excellent in buckling fatigue resistance, bending fatigue resistance, and impact resistance as compared with the friction transmission belts of Comparative Examples 2 and 3. Recognize.

Comparing Examples 2 to 7 in which the conditions other than the value of L2a / L1 are the same, in Examples 2 and 4 to 6 in which L2a / L1 is 8% or more and 28% or less, L2a / L1 exceeds 28%. Compared with Example 3 and Example 7 in which L2a / L1 was less than 8%, both the strong retention rate and the life time after running for 120 hours were good results.

Comparing the test results of Example 9 and Comparative Example 4 having a belt type of C type, the life time of Example 9 was more than twice the life time of Comparative Example 4. Further, in Example 9, the strong retention rate after running for 120 hours was higher than that in Comparative Example 4. Therefore, it can be seen that the friction transmission belt of Example 9 is superior in buckling fatigue resistance, bending fatigue resistance, and impact resistance as compared with the friction transmission belt of Comparative Example 4.

Comparing the test results of Example 10 having a belt type of E type and Comparative Example 5, the life time of Example 10 was more than twice the life time of Comparative Example 5. Further, in Example 10, the strong retention rate after running for 120 hours was higher than that in Comparative Example 5. Therefore, it can be seen that the friction transmission belt of Example 10 is superior in buckling fatigue resistance, bending fatigue resistance, and impact resistance as compared with the friction transmission belt of Comparative Example 5.

1,201,301,401,501,601,701,801 Friction transmission belt 1a, 1b Friction transmission surface 4 Rubber layer 5 Core wire 6,206,306 High-strength fiber sheet 6a, 206a, 306a First fiber bundle 6b, 206b, 306b 2nd fiber bundle 7,307 Adhesive rubber layer 8,308,408,608,708 Compressed rubber layer 9,309,409,509,809 Stretched rubber layer

Claims (9)

An annular friction transmission belt having a V-shaped cross section orthogonal to the belt circumferential direction and friction transmission surfaces on both sides in the belt width direction.
With a rubber layer,
The core wire embedded in the rubber layer and
At least one of the inner peripheral side of the belt and the outer peripheral side of the belt of the core wire has a structure in which high-strength fiber bundles embedded in the rubber layer and in which a plurality of high-strength fibers are flatly aligned are arranged intersecting each other. And with a high-strength fiber sheet having a woven or knitted structure ,
The high-strength fiber bundle constituting the high-strength fiber sheet is composed of only aramid fibers or only carbon fibers.
When the high-strength fiber bundle is composed of only aramid fibers, the thickness of the high-strength fiber sheet is 0.03 to 0.24 mm.
When the high-strength fiber bundle is composed of only carbon fibers, the thickness of the high-strength fiber sheet is 0.05 to 0.09 mm.
The high-strength fiber sheet, intersecting two directions of the tensile strength of the fiber bundles, the friction transmission belt, characterized in der Rukoto 2000N / mm ² or more. The surface of the rubber layer on the inner peripheral side of the belt is covered with a cover cloth exposed to the outside, or is exposed to the outside.
The ratio of the length in the belt thickness direction from the center of the core wire to the high-strength fiber sheet with respect to the maximum length in the belt thickness direction from the center of the core wire to the surface of the rubber layer on the inner peripheral side of the belt. However, the friction transmission belt according to claim 1, wherein the content is 8% or more and 28% or less. The friction transmission belt according to claim 1 or 2, wherein the maximum length in the belt width direction is 12 to 70 mm, and the belt thickness is 5 to 26 mm. The friction transmission according to any one of claims 1 to 3 , wherein the high-strength fiber sheet is arranged so that the two intersecting directions of the fiber bundles are the belt circumferential direction and the belt width direction. belt. Any of claims 1 to 3 , wherein the high-strength fiber sheet is arranged so that the two intersecting directions of the fiber bundles are inclined with respect to the belt circumferential direction and the belt width direction. The friction transmission belt described in the direction. When the fiber bundle is composed of aramid fibers, the basis weight of the high-strength fiber sheet is 90 to 870 g / m ² .
The friction transmission belt according to any one of claims 1 to 5 , wherein when the fiber bundle is composed of carbon fibers, the basis weight of the high-strength fiber sheet is 200 to 300 g / m ^2. The rubber layer is
An adhesive rubber layer in which at least a part of the core wire is embedded,
A compression rubber layer composed of a rubber composition different from the adhesive rubber layer and provided on the inner peripheral side of the belt of the adhesive rubber layer, and a compression rubber layer.
It is composed of a rubber composition different from the adhesive rubber layer, and has an stretchable rubber layer provided on the outer peripheral side of the belt of the adhesive rubber layer.
Claim 1 is characterized in that the high-strength fiber sheet is embedded in at least one of the adhesive rubber layer and the compressed rubber layer and between the adhesive rubber layer and the stretch rubber layer. The friction transmission belt according to any one of 6 to 6. The rubber layer is
With a compressed rubber layer,
It is composed of a rubber composition different from the compressed rubber layer, and has the stretched rubber layer provided on the outer peripheral side of the belt of the compressed rubber layer.
The core wire is embedded between the compressed rubber layer and the stretched rubber layer in the compressed rubber layer or the stretched rubber layer.
Claims 1 to 6 are characterized in that the high-strength fiber sheet is embedded in at least one of the compressed rubber layer, the stretched rubber layer, and the compressed rubber layer and the stretched rubber layer. The friction transmission belt described in any of. The friction transmission belt according to any one of claims 1 to 8 , wherein the high-strength fiber sheet is subjected to an adhesive treatment for enhancing the adhesiveness with the rubber layer.

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