JP2021042853A - Wrapped v-belt transmission device - Google Patents

Abstract

To provide a wrapped V-belt transmission device capable of suppressing capsizing even when used in an application requiring a high horsepower of 8 PS or more/piece, which is a multi-axis layout that repeats continuous bending accompanied by reverse bending.SOLUTION: A belt transmission device comprises: a wrapped V-belt 1 including a core layer 4 including core wires 3 arranged so as to be spaced apart in a belt width direction, a stretch rubber layer 2 laminated on the outer peripheral side of the core layer, a compressed rubber layer laminated on the inner peripheral side of the belt of the core body layer, and an outer cover 6 covering the entire external surface of the belt; and a drive pulley to which the wrapped V-belt can be attached. The belt transmission device adjusts a lateral pressure deformation index expressed by the following formula to 0.1 to 0.49: lateral pressure deformation index=[effective tension (N/piece)/contact area between drive pulley and belt (mm2)]×aspect ratio (in the formula, the aspect ratio indicates belt top width/belt thickness).SELECTED DRAWING: Figure 2

Description

The present invention relates to a belt transmission device including a wrapped V-belt in which a friction transmission surface is formed so as to be inclined in a V shape and is used in a multi-axis layout.

The V-belt that transmits power by friction transmission includes a low-edge (Raw-EDGE) type (low-edge V-belt), which is a rubber layer with an exposed friction transmission surface, and a friction transmission surface (V-shaped side surface) covered with a cover cloth. There is a wrapped type (wrapped V-belt), which is used properly according to the application due to the difference in the surface texture (friction coefficient between the rubber layer and the cover cloth) of the friction transmission surface. These V-belts are used in a wide range of fields such as automobiles and industrial machines, and are used at high loads due to an increase in transmission capacity and an increase in the size of a device. Therefore, the V-belt is required to increase the rigidity (side pressure resistance) in the belt width direction in order to prevent buckling deformation (dishes).

For example, the following Patent Documents 1 to 3 propose a friction transmission belt devised to enhance lateral pressure resistance. Usually, in order to secure lateral pressure resistance, a rubber composition having a large mechanical property reinforced by blending short fibers or the like is used for the compressed rubber layer and the stretched rubber layer.

Japanese Patent Application Laid-Open No. 10-238596 (Patent Document 1) describes an adhesive rubber layer in which a cord is embedded, an stretch rubber layer and a compressed rubber layer laminated via the adhesive rubber layer, and the stretch rubber layer and compression. In a transmission V-belt having a canvas layer laminated on at least one of the rubber layers, the rubber layers are exposed on both side surfaces, and the bottom surface is formed in a cog shape, at least the stretch rubber layer and the compressed rubber layer are formed. One rubber hardness should be set in the range of 90 to 96 °, the rubber hardness of the adhesive rubber layer should be set in the range of 83 to 89 °, and aramid short fibers should be oriented in the belt width direction for the stretch rubber layer and the compressed rubber layer to withstand lateral pressure. It is described to improve sex.

Further, in Japanese Patent Application Laid-Open No. 2009-150538 (Patent Document 2), the rubber hardness of the stretched rubber layer is in the range of 85 to 92, the rubber hardness of the compressed rubber layer is in the range of 90 to 98, and compression is performed. A cogged V-belt in which the rubber hardness of the rubber layer is set to be 3 to 10 or more higher than the rubber hardness of the stretchable rubber layer is disclosed. This cogged V-belt suppresses dishing even in high load transmission, is less likely to cause vertical peeling of the belt and popping out of the core wire at the embedded portion of the core wire, and also has flexibility of the belt.

Further, in Japanese Patent Application Laid-Open No. 2010-196888 (Patent Document 3), the compressed rubber layer is composed of at least two layers, an upper layer close to the core wire and a lower layer on the inner peripheral surface side of the belt, and the hardness of the upper layer is higher than that of the lower layer. A power transmission belt set (the hardness of the upper layer is in the range of 93 to 99 and the hardness of the lower layer is in the range of 80 to 88) is disclosed. In this document, the deformation resistance of the belt can be improved by the upper layer having high hardness, but the rubber having low hardness is arranged in the lower layer of the belt which is greatly deformed by receiving the largest stress when the belt is bent. Therefore, it is described that it has excellent bending fatigue resistance and can prevent cracks from occurring.

By the way, in a threshing device mounted on a combine (harvester) representing an agricultural machine, a multi-axis layout in which a drive shaft linked to an engine and a plurality of work shafts are suspended by one long V-belt. Is adopted, and the suspended long V-belt is often used under harsh running conditions in which continuous bending accompanied by not only forward bending but also reverse bending is repeated.

Further, in this application, a wrapped V-belt in which the entire surface of the belt including the friction transmission surface is covered with a cover cloth is used. The reason is that if a low-edge V-belt, which is a rubber layer with an exposed friction transmission surface, is used, the friction coefficient of the transmission surface is high and the stress applied to the belt increases, leading to early cutting, and rubber due to exhaust wall entwined with the belt. This is because there is a risk of damage. By using the wrapped V-belt, the coefficient of friction of the transmission surface becomes small, and the stress applied to the belt due to an appropriate slip is relieved. In addition, the transmission surface is protected and is less likely to be damaged.

In recent years, the horsepower of the device has been increased [the load applied to one belt (reference transmission capacity) is 8 PS or more], and the stress applied to the belt has increased. Since the conventional wrapped V-belt has insufficient lateral pressure resistance, buckling deformation (dishes) may occur due to the lateral pressure from the pulley, and self-heating (internal loss due to heat generation) may occur due to the deformation. When the buckling deformation becomes excessive, the shear stress generated from the inside of the V-belt is concentrated near the core wire layer (the interface between the core wire and the adhesive rubber layer and the interface between the adhesive rubber layer and the compressed rubber layer). Peeling may occur. Further, the rubber may be deteriorated due to self-heating due to deformation, and the adhesive force between the core wire and the rubber may be reduced, which may lead to the core wire peeling. As a result, the tensions of the core wires arranged in the width direction of the belt become non-uniform during running. Therefore, as shown in FIG. 1, if the belt loses its balance during running, it runs at an angle and eventually capsizes ( There is a risk of inversion).

Therefore, a long V-belt is used, which is suitable for a multi-axis layout that repeats continuous bending accompanied by reverse bending, and secures lateral pressure resistance that can be applied to high horsepower [8 PS or more / piece]. It became necessary to design a product of a wrapped V-belt that could be used.

On the other hand, in Japanese Patent No. 6567210 (Patent Document 4), the compressed rubber layer is a first compressed rubber layer laminated on the outer peripheral side of the belt and a second compressed rubber layer laminated on the inner peripheral side of the belt. A wrapped V-belt in which the rubber hardness of the stretched rubber layer is higher than the rubber hardness of the second compressed rubber layer and lower than the rubber hardness of the first compressed rubber layer is disclosed.

JP-A-10-238596 (Claim 1, paragraph [0008]) JP-A-2009-150538 (Claim 1, paragraph [0010]) JP-A-2010-196888 (Claim 1, paragraphs [0013] [0025]) Japanese Patent No. 6567210 (Claim 1)

However, the friction transmission belts of Patent Documents 1 to 3 that can improve the lateral pressure resistance are short lengths used in a two-axis layout used in a belt type transmission such as a vehicle such as a scooter or an automobile or a machine for general industry. Since it is a V-belt and is not used in such a way that the belt may overturn, the product design is not designed to prevent overturning. In addition, the design is related to a low-edge V-belt, and it is necessary to consider the difference in friction coefficient. Therefore, the formulations of Patent Documents 1 to 3 cannot be simply applied to the above product design, and a new product design is required.

On the other hand, the wrapped V-belt of Patent Document 4 is a belt capable of preventing capsizing peculiar to a multi-axis layout (layout as shown in FIG. 6 in the evaluation test of Examples described later) that repeats continuous bending accompanied by reverse bending. is there. That is, in a state where the wrapped V-belt is wound around each pulley and bent, the rubber layer on the outer peripheral side is deformed to be stretched and the rubber layer on the inner peripheral side is deformed to be compressed. In addition, when the rubber is wound by reverse bending, the relationship between the outer peripheral side and the inner peripheral side is reversed, and in any case, the rubber composition is less likely to be deformed (stretched or compressed) into the outer peripheral side or inner peripheral side rubber layer. When an object is used, the flexibility is reduced. As a result, when the wrapping property around the pulley is reduced, it becomes difficult for the belt to fit into the V-groove of the pulley, and capsizing is likely to occur during traveling. On the other hand, if a flexible rubber composition that is easily deformed is used with priority given to flexibility (fitness to the pulley), the lateral pressure resistance to the pulley is lowered. As a result, even if the lateral pressure resistance is lowered, the buckling deformation becomes large, so that it becomes easy to capsize. That is, in this application, the balance between flexibility (fitting to the pulley) and lateral pressure resistance is important, but the wrapped V-belt of Patent Document 4 has a layer (first compression rubber) in the central portion in the belt thickness direction. By increasing the hardness and strength of the layer) as much as possible and adjusting the hardness of the stretched rubber layer and the second compressed rubber layer, which are the outer peripheral side or inner peripheral side layers, to an appropriate range (not too high or too low). The overturning resistance is improved. However, as a result of examination by the present inventor, it has been found that when the belt is actually run, the susceptibility to capsizing changes depending on the running conditions.

Therefore, an object of the present invention is a multi-axis layout that repeats continuous bending accompanied by reverse bending, and is used for applications that require high horsepower of 8 PS or more / piece (severe multi-axis layout application). Also, it is an object of the present invention to provide a wrapped V-belt transmission device capable of suppressing capsizing.

Another object of the present invention is to provide a wrapped V-belt transmission device which is excellent in lateral pressure resistance and can improve durability even when used in a severe multi-axis layout application.

As a result of continuing the study based on the above-mentioned findings, the present inventor has a great influence on the magnitude of the effective tension applied to the belt under the running conditions of the belt, and the buckling deformation property with respect to the lateral pressure changes depending on the effective tension. Therefore, it was found that the overturning resistance changed significantly. Furthermore, even when the same effective tension is applied, the deformation property with respect to lateral pressure, that is, the overturning resistance, is affected by the contact area between the belt and the pulley and the aspect ratio (ratio of width and thickness) of the belt. It was revealed. That is, as a result of diligent studies, the present inventor has determined that the deformability to lateral pressure (overturn resistance) is the effective tension, the contact area between the belt and the pulley, and the aspect ratio of the belt (ratio of width and thickness). By adjusting these conditions, it is a multi-axis layout that repeats continuous bending accompanied by reverse bending, and it is used for applications that require high horsepower of 8 PS or more / piece. Even so, we have found that overturning can be suppressed and completed the present invention.

That is, in the belt transmission device of the present invention, the core body layer including the core wires arranged at intervals in the belt width direction, the stretch rubber layer laminated on the outer peripheral side of the belt of the core body layer, and the core body layer. A belt transmission device including a wrapped V-belt including a compressed rubber layer laminated on the inner peripheral side of the belt and an outer cover covering the entire outer surface of the belt, and a drive pulley to which the wrapped V-belt can be attached. , The lateral pressure deformation index expressed by the following formula is 0.1 to 0.49.

Lateral pressure deformation index = [effective tension (N / piece) / contact area between drive pulley and belt (mm ² )] x aspect ratio (in the formula, aspect ratio indicates belt top width / belt thickness).

The lateral pressure deformation index may be 0.12 to 0.47. The ratio X of the total value of the adjacent core wire intervals to the belt width in the core body layer may be 5 to 17%. The compressed rubber layer includes a first compressed rubber layer laminated on the outer peripheral side of the belt and a second compressed rubber layer laminated on the inner peripheral side of the belt, and the rubber hardness of the stretched rubber layer is the second compression. It may be higher than the rubber hardness of the rubber layer and lower than the rubber hardness of the first compressed rubber layer. The coefficient of friction of the outer cover, which is the transmission surface, may be 0.91 to 0.96. A reinforcing cloth layer may be interposed between the inner peripheral surface of the compressed rubber layer and the outer cloth.

In the present invention, a core body layer including core wires arranged at intervals in the belt width direction, an stretch rubber layer laminated on the outer peripheral side of the belt of the core body layer, and laminated on the inner peripheral side of the core body layer. The lateral pressure deformation index is adjusted to 0.1 to 0.49 in the belt transmission device including the wrapped V-belt including the compressed rubber layer and the outer cover and the drive pulley to which the wrapped V-belt can be attached. Therefore, overturning can be suppressed even when used for harsh multi-axis layout applications. Furthermore, the lateral pressure resistance can be improved, and the durability can be improved even when used for harsh multi-axis layout applications.

FIG. 1 is a schematic cross-sectional view showing a state in which the wrapped V-belt is tilted and running and a state in which the wrapped V-belt is overturned. FIG. 2 is a schematic cross-sectional view of an example of the wrapped V-belt of the present invention. FIG. 3 is a schematic cross-sectional view for explaining a method of measuring the ratio X. FIG. 4 is a schematic cross-sectional view of another example of the wrapped V-belt of the present invention. FIG. 5 is a schematic view for explaining a method of measuring the friction coefficient in the embodiment. FIG. 6 is a schematic view for explaining a running test of the JIS B type wrapped V-belt obtained in Example 1. FIG. 7 is a schematic cross-sectional view showing a laminated structure of the wrapped V-belts in the embodiment. FIG. 8 is a schematic cross-sectional view showing a state in which the B-shaped wrapped V-belt is attached to the drive pulley in the embodiment.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, if necessary.

The belt transmission device of the present invention includes a wrapped V-belt and a drive pulley to which the wrapped V-belt can be mounted or fitted. The wrapped V-belt is a conventional wrapped V-belt except that the compressed rubber layer has a laminated structure including two types of compressed rubber layers having different rubber hardness and the rubber hardness of each layer is adjusted. There may be. A conventional wrapped V-belt is an endless V-shaped belt having, for example, a compression rubber layer on the inner peripheral side, an stretch rubber layer on the outer peripheral side, and a core body layer (adhesive rubber layer) in which a core wire is embedded, which is interposed between them. It consists of a belt body with a shaped cross section and an outer cover cloth (cover cloth) that covers the circumference of the V-shaped cross section of the belt main body over the entire length in the belt peripheral length direction, and the V-shaped cross section covered with the outer cover cloth. The left and right sides of the V-belt may be a V-belt having friction transmission surfaces. In the V-shaped cross section, the side with a wide belt width is the outer peripheral side, and the side with a narrow belt width is the inner peripheral side.

FIG. 2 is a schematic cross-sectional view of an example of the wrapped V-belt of the present invention. In the wrapped V-belt 1 shown in FIG. 2, the stretch rubber layer (or upper core rubber layer) 2 and the core wire 3 are embedded in the vulture rubber composition from the outer peripheral side of the belt, and the core body layer (adhesive rubber layer) 4 , The first compression rubber layer (first V-core rubber layer) 5a and the second compression rubber layer (second V-core rubber layer) 5b are sequentially laminated to form an endless belt body, and the circumference of the belt body is in the belt circumferential direction. It is formed of an outer cover 6 (woven fabric, knitted fabric, non-woven fabric, etc.) that covers the entire length. In this example, the core wire 3 is a core wire (twisted cord) arranged at predetermined intervals in the belt width direction. Further, in this example, the core body layer 4 is formed of a vulcanized rubber composition in which the core wire 3 is embedded, but the core body layer is arranged at the interface between the stretch rubber layer and the compressed rubber layer. It may be formed only by the core wire 3. In the present application, when the core body layer is formed only of core wires, the core wires arranged at intervals in the belt body are referred to as core body layers, and in such a core body layer, the core wires are extended. Not only the form arranged at the interface between the rubber layer and the compressed rubber layer, but also a part or all of the core wires arranged at the interface between the stretched rubber layer and the compressed rubber layer may be the stretched rubber layer or the stretched rubber layer in the manufacturing process. The form embedded in the compressed rubber layer is also included.

In the present invention, in a belt transmission device including such a wrapped V-belt and a drive pulley to which the wrapped V-belt can be mounted, one belt is used as a usage condition that affects the deformability (overturn resistance) with respect to lateral pressure. By adjusting the relationship between the effective tension per unit, the contact area between the belt and the drive pulley, and the aspect ratio (ratio of width and thickness) of the belt, we succeeded in improving the overturning resistance.

Specifically, the belt transmission device of the present invention has a lateral pressure deformation index expressed by the following formula of 0.1 to 0.49 (particularly 0.12 to 0.47), preferably 0.2 to 0. It is .47, more preferably 0.25 to 0.46, more preferably 0.3 to 0.45, and most preferably 0.35 to 0.43. If the lateral pressure deformation index is too small, the power transmission property of the belt may decrease, and if it is too large, the overturning resistance may decrease.

Lateral pressure deformation index = [effective tension (N / piece) / contact area between drive pulley and belt (mm ² )] x aspect ratio (in the formula, aspect ratio indicates belt top width / belt thickness).

In the present application, the method for measuring the lateral pressure deformation index can be measured by the method described in Examples described later.

In particular, as will be described later, the hardness and strength of the central portion in the belt thickness direction (first compressed rubber layer) are made as high as possible, and the stretched rubber layer and the second compressed rubber layer which are the outer peripheral side or inner peripheral side layers are made as high as possible. If the lateral pressure deformation index of the wrapped V-belt whose hardness is adjusted to an appropriate range is adjusted to the above range, the overturning resistance can be highly improved.

In the wrapped V-belt of the present invention, the width of the outer peripheral surface of the belt may be, for example, 15 to 35 mm (particularly 16 to 25 mm), and the thickness of the wrapped V-belt is, for example, 10 to 20 mm (particularly 10 to 15 mm). You may.

[Compressed rubber layer]
In the present invention, the compressed rubber layer is a first compressed rubber layer laminated on the outer peripheral side of the belt and a second compressed rubber layer laminated on the inner peripheral side of the belt, which has a lower rubber hardness than the first compressed rubber layer. It has a laminated structure of two or more layers including and, and by adjusting the rubber hardness of the stretch rubber layer to be lower than that of the first compressed rubber layer and higher than that of the second compressed rubber layer, the lateral pressure resistance of the belt can be improved. Can be improved.

The compressed rubber layer may include a first compressed rubber layer and a second compressed rubber layer, and may have a laminated structure of three or more layers. However, from the viewpoint of lateral pressure resistance and productivity, the first compression is performed. A two-layer structure including a rubber layer and a second compressed rubber layer is preferable.

The rubber hardness of the first compressed rubber layer is larger than the rubber hardness of either the second compressed rubber layer or the stretched rubber layer, and the difference in rubber hardness Hs (JIS A) between the first compressed rubber layer and the stretched rubber layer (No. 1). 1 The rubber hardness of the compressed rubber layer − the rubber hardness of the stretched rubber layer) may be, for example, 1 ° or more, preferably 1 to 10 ° (for example, 3 to 10 °), and more preferably 2 to 7 ° (for example, 2 °). ~ 5 °), more preferably 3-5 ° (particularly 3-4 °). If the difference in rubber hardness between the two layers is too small, the overturning resistance in harsh multi-axis layout applications may decrease, and conversely if it is too large, the overturning resistance may decrease.

The rubber hardness Hs of the first compressed rubber layer can be selected from, for example, in the range of about 80 to 100 °, preferably 90 to 95 °, more preferably 91 to 95 °, and even more preferably 92 to 94 °. If the rubber hardness is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

The rubber hardness Hs of the second compressed rubber layer is smaller than the rubber hardness of either the first compressed rubber layer or the stretched rubber layer, and the difference in rubber hardness Hs between the first compressed rubber layer and the second compressed rubber layer (first). The rubber hardness of the compressed rubber layer − the rubber hardness of the second compressed rubber layer) may be, for example, 1 ° or more (particularly 5 ° or more), preferably 5 to 30 ° (for example, 7 to 27 °), and more preferably. It is 10 to 25 ° (for example, 12 to 21 °), more preferably 12 to 20 ° (particularly 15 to 20 °), more preferably 15 to 18 °, and most preferably 16 to 18 °. The difference in rubber hardness Hs between the stretched rubber layer and the second compressed rubber layer (rubber hardness of the stretched rubber layer − rubber hardness of the second compressed rubber layer) is, for example, 5 to 30 ° (for example, 7 to 25 °), preferably 7 to 25 °. It is 10 to 20 ° (for example, 12 to 18 °), more preferably 13 to 15 °. If the difference in rubber hardness between the second compressed rubber layer and the first compressed rubber layer or stretched rubber layer is too small, the overturning resistance in harsh multi-axis layout applications may decrease, and conversely, if it is too large. There is a risk that the overturning resistance will decrease.

The rubber hardness Hs of the second compressed rubber layer can be selected from, for example, in the range of about 60 to 90 °, preferably 72 to 80 °, more preferably 73 to 78 °, still more preferably 75 to 78 °, and most preferably 75. ~ 77 °. If the rubber hardness is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

In the present application, the rubber hardness of each rubber layer conforms to the spring hardness test (A type) specified in JIS K6253 (2012) (vulverized rubber and thermoplastic rubber-how to determine the hardness-). It indicates the measured value Hs (JIS A) and may be simply described as rubber hardness.

The tensile elastic modulus (modulus) of the first compressed rubber layer is, for example, 25 to 50 MPa, preferably 30 to 40 MPa, and more preferably 35 to 40 MPa in the belt width direction. If the tensile elastic modulus is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

The tensile elastic modulus (modulus) of the second compressed rubber layer is, for example, 12 to 20 MPa, preferably 13 to 18 MPa, and more preferably 14 to 17 MPa in the belt width direction. If the tensile elastic modulus is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

In the present application, the tensile elastic modulus (modulus) of each rubber layer can be measured by a method according to JIS K6251 (1993).

The average thickness of the entire compressed rubber layer is, for example, 1 to 12 mm, preferably 2 to 10 mm, and more preferably 2.5 to 9 mm (particularly 3 to 5 mm).

The average thickness of the first compressed rubber layer can be selected from the range of, for example, about 95 to 30% with respect to the average thickness of the entire compressed rubber layer, preferably 90 to 50%, more preferably 85 to 55%, still more preferably. Is 80-60% (especially 70-65%). This ratio may be the ratio when the compression rubber layer is composed of only the first compression rubber layer and the second compression rubber layer (that is, L2 / L1 in FIG. 2). If the thickness ratio of the first compressed rubber layer is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

The compressed rubber layer may further include other compressed rubber layers having different rubber hardness in addition to the first compressed rubber layer and the second compressed rubber layer. The other compression rubber layer may be a single layer or a plurality of layers. Further, the other compression rubber layer may be laminated on either the upper or lower surface of the first compression rubber layer or the lower surface of the second compression rubber layer. The average thickness of the other compressed rubber layers may be, for example, 30% or less, preferably 10% or less, and more preferably 5% or less with respect to the average thickness of the entire compressed rubber layer. That is, the compressed rubber layer preferably includes the first compressed rubber layer and the second compressed rubber layer as the main layers, and the total average thickness of the first compressed rubber layer and the second compressed rubber layer is the compressed rubber layer. For example, it may be 70% or more, preferably 90% or more, more preferably 95% or more with respect to the total average thickness, and the compressed rubber layer is from only the first compressed rubber layer and the second compressed rubber layer. Is particularly preferable.

The compressed rubber layer may be formed of a vulcanized rubber composition commonly used as a rubber composition of a wrapped V-belt. The vulcanized rubber composition may be a vulcanized rubber composition containing a rubber component, and by appropriately adjusting the composition of the composition, each layer constituting the compressed rubber layer, particularly the first compressed rubber layer and the second compressed rubber layer The rubber hardness of the compressed rubber layer can be adjusted. The method for adjusting the rubber hardness and the like is not particularly limited, and the composition and / or type of the components constituting the composition may be changed and adjusted. From the viewpoint of convenience and the like, the ratio of short fibers and fillers and / Alternatively, it is preferable to change the type for adjustment.

(1st compression rubber layer)
(A) Rubber component The rubber component constituting the sulfide rubber composition forming the first compressed rubber layer can be selected from known vulverable or crosslinkable rubbers and / or polymers, for example, diene rubber [natural]. Rubber, isoprene rubber, butadiene rubber, chloroprene rubber (CR), styrene butadiene rubber (SBR), vinylpyridine-styrene-butadiene copolymer rubber, acrylonitrile butadiene rubber (nitrile rubber); hydride nitrile rubber (hydrogenated nitrile rubber) The hydrogenated product of the diene rubber such as (including a mixed polymer with an unsaturated carboxylic acid metal salt)], olefin rubber [for example, ethylene-α-olefin rubber (ethylene-α-olefin elastomer), polyocteni Ren rubber, ethylene-vinyl acetate copolymer rubber, chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, etc.], epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluorine rubber, etc. can be exemplified. These rubber components can be used alone or in combination of two or more.

Of these, ethylene-α-olefin elastomers [ethylene-propylene copolymer (EPM), ethylene-propylene-diene ternary copolymer (EPDM), etc.) are used because the vulcanizing agent and vulcanization accelerator are easily diffused. Ethylene-α-olefin rubber] and chloroprene rubber are widely used, and especially when used in a high load environment such as a speed change belt, the balance of mechanical strength, weather resistance, heat resistance, cold resistance, oil resistance, adhesiveness, etc. From the viewpoint of superiority, chloroprene rubber and EPDM are preferable. Further, chloroprene rubber is particularly preferable because it is excellent in wear resistance in addition to the above-mentioned characteristics. The chloroprene rubber may be a sulfur-modified type or a non-sulfur-modified type.

When the rubber component contains chloroprene rubber, the proportion of chloroprene rubber in the rubber component may be 50% by mass or more (particularly 80 to 100% by mass), and 100% by mass (only chloroprene rubber) is particularly preferable.

(B) Short Fibers The vulcanized rubber composition may further contain short fibers in addition to the rubber components. Examples of the short fibers include polyolefin fibers (for example, polyethylene fibers, polypropylene fibers, etc.), polyamide fibers (for example, polyamide 6 fibers, polyamide 66 fibers, polyamide 46 fibers, aramid fibers, etc.), and polyalkylene allylate fibers [for example, , Polyethylene terephthalate (PET) fiber, polytrimethylene terephthalate (PTT) fiber, polybutylene terephthalate (PBT) fiber, polyethylene naphthalate (PEN) fiber, C _2-4 alkylene C _8-14 allylate fiber, etc.], Viniron Examples thereof include synthetic fibers such as fibers, polyvinyl alcohol-based fibers and polyparaphenylene benzobisoxazole (PBO) fibers; natural fibers such as cotton, hemp and wool; and inorganic fibers such as carbon fibers. These short fibers can be used alone or in combination of two or more.

Among these short fibers, synthetic fibers or natural fibers, in particular, ethylene terephthalate, C _2-4 polyester fibers alkylene C _6-12 arylate main constituent units such as ethylene-2,6-naphthalate (polyalkylene arylate Fibers), synthetic fibers such as polyamide fibers (aramid fibers, etc.), inorganic fibers such as carbon fibers, etc. are widely used, among which rigid, high-strength and modulus fibers such as polyester fibers (particularly polyethylene terephthalate fibers, polyethylene fibers) Phthalate fibers) and polyamide fibers (particularly aramid fibers) are preferable. Aramid fibers also have high wear resistance. Therefore, the short fibers preferably contain at least total aromatic polyamide fibers such as aramid fibers. The aramid fiber may be a commercially available product such as the trade names "Conex", "Nomex", "Kevlar", "Technora", and "Twaron".

The average fiber diameter of the short fibers is, for example, 2 μm or more, preferably 2 to 100 μm, more preferably 3 to 50 μm (for example, 5 to 50 μm), still more preferably 7 to 40 μm (particularly 10 to 30 μm). The average length of the short fibers is, for example, 1 to 20 mm, preferably 1.5 to 10 mm, more preferably 2 to 5 mm (particularly 2.5 to 4 mm).

From the viewpoint of dispersibility and adhesiveness of the short fibers in the rubber composition, the short fibers may be bonded (or surface-treated) by a conventional method. Examples of the surface treatment method include a method of treating with a treatment liquid containing a conventional surface treatment agent. As the surface treatment agent, for example, an RFL solution containing resorcin (R), formaldehyde (F) and rubber or latex (L) [for example, a condensate of resorcin (R) and formaldehyde (F) (RF condensate)). The rubber component, for example, an RFL liquid containing a vinylpyridine-styrene-butadiene copolymer rubber], an epoxy compound, a polyisocyanate compound, a silane coupling agent, and a vulcanized rubber composition (for example, a surface silanol group). A vulcanized rubber composition containing a wet method white carbon containing hydrous silicic acid as a main component, which is advantageous for enhancing the chemical bonding force with rubber, and the like). These surface treatment agents may be used alone or in combination of two or more, and the short fibers may be treated with the same or different surface treatment agents several times in sequence.

The short fibers may be oriented in the belt width direction and embedded in the compressed rubber layer in order to suppress the compressive deformation of the belt due to the pressure from the pulley.

The ratio of the short fibers is, for example, 5 to 50 parts by mass, preferably 10 to 30 parts by mass, and more preferably 15 to 25 parts by mass (particularly 18 to 22 parts by mass) with respect to 100 parts by mass of the rubber component. If the proportion of short fibers is too small, the rubber hardness of the first compressed rubber layer may decrease, and if it is too large, the rubber hardness may be too high and the fit with the pulley groove may decrease.

(C) Filler The vulcanized rubber composition may further contain a filler in addition to the rubber component. Examples of the filler include carbon black, silica, clay, calcium carbonate, talc, mica and the like. The filler often contains a reinforcing filler, and such a reinforcing filler may be carbon black, reinforcing silica, or the like. Generally, the reinforcing property of silica is smaller than the reinforcing property of carbon black. These fillers can be used alone or in combination of two or more. In the present invention, in order to improve the lateral pressure resistance, it is preferable to contain a reinforcing filler, and it is particularly preferable to contain carbon black.

The average particle size (number average primary particle size) of carbon black is, for example, 5 to 200 nm, preferably 10 to 150 nm, more preferably 15 to 100 nm, and may be a small particle size from the viewpoint of high reinforcing effect. For example, it may be 5 to 38 nm, preferably 10 to 35 nm, and more preferably 15 to 30 nm. Examples of the carbon black having a small particle size include SAF, ISAF-HM, ISAF-LM, HAF-LS, HAF, and HAF-HS. These carbon blacks can be used alone or in combination of two or more.

In the present invention, even if a large amount of carbon black is blended, the decrease in workability can be suppressed, so that the mechanical properties (elastic modulus) of the first compressed rubber layer can be improved. Further, carbon black can reduce the friction coefficient of the first compressed rubber layer and improve the wear resistance of the first compressed rubber layer.

The ratio of the filler (particularly carbon black) is, for example, 10 to 100 parts by mass, preferably 20 to 80 parts by mass, and more preferably 30 to 70 parts by mass (particularly 40 to 60 parts by mass) with respect to 100 parts by mass of the rubber component. It may be about. If the proportion of the filler is too small, the elastic modulus may be insufficient and the lateral pressure resistance and durability may be lowered, and if it is too large, the elastic modulus may be too high and the fit with the pulley groove may be deteriorated. is there.

The proportion of carbon black may be, for example, 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass with respect to the entire filler. If the ratio of carbon black to the entire filler is too small, the rubber hardness of the first compressed rubber layer may decrease.

(D) Other Additives The vulcanized rubber composition may be a vulcanizing agent or a cross-linking agent, a co-cross-linking agent, a vulcanization aid, a vulcanization accelerator, a vulcanization retarder, or a metal oxide (as needed). Calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide, etc.), softeners (oils such as paraffin oil, naphthenic oil, etc.), processing agents or processing aids (eg, fatty acids such as stearic acid) , Fatty metal salts such as stearic acid metal salt, fatty acid amide such as stearate amide, wax, paraffin, etc.), Adhesive improver [for example, resorcin-formaldehyde cocondensate (RF condensate), amino resin (nitrogen-containing cyclic) Condensations of compounds and formaldehyde, such as melamine resins such as hexamethylol melamine and hexaalkoxymethyl melamine (hexamethoxymethyl melamine, hexabutoxymethyl melamine, etc.), urea resins such as methylol urea, benzoguanamine resins such as methylol benzoguanamine resin, etc. ), These cocondensates (resorcin-melamine-formaldehyde cocondensate, etc.)], anti-aging agents (antioxidants, heat anti-aging agents, bending crack inhibitors, ozone deterioration inhibitors, etc.), colorants, It may contain a tackifier, a plasticizer, a lubricant, a coupling agent (silane coupling agent, etc.), a stabilizer (ultraviolet absorber, heat stabilizer, etc.), a flame retardant, an antistatic agent, and the like. The metal oxide may act as a cross-linking agent. Further, in the adhesiveness improving agent, the resorcin-formaldehyde cocondensate and the amino resin may be an initial condensate (prepolymer) of a nitrogen-containing cyclic compound such as resorcin and / or melamine and formaldehyde.

As the vulcanizing agent or the cross-linking agent, conventional components can be used depending on the type of rubber component. For example, the metal oxide vulcanizing agent (magnesium oxide, zinc oxide, lead oxide, etc.) and organic peroxide (diacyl) Peroxide, peroxyester, dialkyl peroxide, etc.), sulfur-based vulcanizer, and the like can be exemplified. Examples of the sulfur-based sulfurizing agent include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and sulfur chloride (sulfur monochloride, sulfur dichloride, etc.). These cross-linking agents or vulcanizing agents can be used alone or in combination of two or more. When the rubber component is chloroprene rubber, a metal oxide (magnesium oxide, zinc oxide, etc.) may be used as a vulcanizing agent or a cross-linking agent. The metal oxide may be used in combination with another vulcanizing agent (sulfur-based vulcanizing agent, etc.), and the metal oxide and / or the sulfur-based vulcanizing agent may be used alone or in combination with a vulcanization accelerator. It may be used in combination.

The ratio of the vulcanizing agent can be selected from the range of, for example, about 1 to 20 parts by mass with respect to 100 parts by mass of the rubber component in terms of solid content, depending on the type of the vulcanizing agent and the rubber component. For example, the ratio of the metal oxide as a vulcanizing agent is, for example, 1 to 20 parts by mass, preferably 3 to 17 parts by mass, and more preferably 5 to 15 parts by mass (particularly 7 to 7 to 15 parts by mass) with respect to 100 parts by mass of the rubber component. 13 parts by mass). When the metal oxide and the sulfur-based vulcanizer are combined, the ratio of the sulfur-based vulcanizer is, for example, 0.1 to 50 parts by mass, preferably 1 to 30 parts by mass with respect to 100 parts by mass of the metal oxide. More preferably, it is 3 to 10 parts by mass. The ratio of the organic peroxide is, for example, 1 to 8 parts by mass, preferably 1.5 to 5 parts by mass, and more preferably 2 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component.

Examples of the co-crosslinking agent (cross-linking aid or co-fragmenting agent co-agent) include known cross-linking aids such as polyfunctional (iso) cyanurate [eg, triallyl isocyanurate (TAIC), triallyl cyanurate (TAC). ) Etc.], polydiene (eg, 1,2-polybutadiene, etc.), metal salts of unsaturated carboxylic acids [eg, (meth) acrylic acid polyvalent metal salts such as zinc (meth) acrylate, magnesium (meth) acrylate. ], Oxims (eg, quinonedioximes), guanidines (eg, diphenylguanidine, etc.), polyfunctional (meth) acrylates [eg, alkanes such as ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate. Alkane polyol poly (meth) acrylates such as diol di (meth) acrylate, trimethylolpropantri (meth) acrylate, pentaerythritol tetra (meth) acrylate], bismaleimides (aliphatic bismaleimide, for example, N, N'- Alkylene bismaleimides such as 1,2-ethylene dimaleimide, N, N'-hexamethylene bismaleimide, 1,6'-bismaleimide- (2,2,4-trimethyl) cyclohexane; allene bismaleimide or aromatic bismaleimide , For example, N, N'-m-phenylenedi maleimide, 4-methyl-1,3-phenylesimareimide, 4,4'-diphenylmethane dimaleimide, 2,2-bis [4- (4-maleimide phenoxy) phenyl. ] Propane, 4,4'-diphenyl ether dimaleimide, 4,4'-diphenyl sulfone dimaleimide, 1,3-bis (3-maleimide phenoxy) benzene, etc.). These cross-linking aids can be used alone or in combination of two or more. Among these cross-linking aids, polyfunctional (iso) cyanurate, polyfunctional (meth) acrylate, and bismaleimides (arene bismaleimide such as N, N'-m-phenylenedimaleimide or aromatic bismaleimide) are preferable. Bismaleimides are often used. By adding a cross-linking aid (for example, bismaleimides), the degree of cross-linking can be increased and adhesive wear can be prevented.

The ratio of the co-crosslinking agent (crosslinking aid) such as bismaleimides is, for example, 0.1 to 10 parts by mass, preferably 0.5 to 8 parts by mass, based on 100 parts by mass of the rubber component in terms of solid content. More preferably, it is 1 to 5 parts by mass (particularly 2 to 4 parts by mass).

Examples of the sulfide accelerator include thiuram-based accelerators [for example, tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), tetrabutylthiuram disulfide (TBTD). ), Dipentamethylene thiuram tetrasulfide (DPTT), N, N'-dimethyl-N, N'-diphenylthium disulfide, etc.], thiazol-based accelerators [eg, 2-mercaptobenzothiazol, 2 -Zinc salt of mercaptobenzothiazol, 2-mercaptothiazolin, dibenzothiazil disulfide, 2- (4'-morpholinodithio) benzothiazole, etc.], sulfenamide accelerators [eg, N-cyclohexyl-2] -Benzothiazyl sulfenamide (CBS), N, N'-dicyclohexyl-2-benzothiazyl sulfenamide, etc.], guanidines (diphenylguanidine, dio-tolylguanidine, etc.), urea-based or thiourea-based accelerators (For example, ethylenethiourea), dithiocarbamates, xanthogenates and the like can be mentioned. These vulcanization accelerators can be used alone or in combination of two or more. Among these vulcanization accelerators, TMTD, DPTT, CBS and the like are widely used.

The ratio of the vulcanization accelerator is, for example, 0.1 to 15 parts by mass, preferably 0.3 to 10 parts by mass (for example, 0.5 to 5 parts by mass) with respect to 100 parts by mass of the rubber component in terms of solid content. , More preferably 0.5 to 3 parts by mass (particularly 0.5 to 1.5 parts by mass).

The ratio of the softener (oils such as naphthenic oil) is, for example, 1 to 30 parts by mass, preferably 3 to 20 parts by mass, and more preferably 3 to 10 parts by mass with respect to 100 parts by mass of the rubber component in terms of solid content. It is a mass part (particularly 3 to 8 parts by mass).

The ratio of the processing agent or processing aid (such as stearic acid) is, for example, 10 parts by mass or less (for example, 0 to 10 parts by mass), preferably 0.1 to 5 parts by mass, relative to 100 parts by mass of the rubber component in terms of solid content. It is by mass (for example, 0.5 to 3 parts by mass), more preferably 1 to 3 parts by mass (particularly 1.5 to 2.5 parts by mass).

The ratio of the adhesiveness improving agent (resorcin-formaldehyde cocondensate, hexamethoxymethylmelamine, etc.) is, for example, 0.1 to 20 parts by mass (for example, 0.2 to 20 parts by mass) with respect to 100 parts by mass of the rubber component in terms of solid content. 10 parts by mass), preferably 0.3 to 5 parts by mass (for example, 0.5 to 2.5 parts by mass), more preferably 0.5 to 3 parts by mass (particularly 0.5 to 1.5 parts by mass). Is.

The ratio of the anti-aging agent is, for example, 0.5 to 15 parts by mass, preferably 1 to 10 parts by mass, and more preferably 2.5 to 7.5 parts by mass with respect to 100 parts by mass of the rubber component in terms of solid content. (Especially 3 to 7 parts by mass).

(Second compression rubber layer)
As the rubber component constituting the vulcanized rubber composition forming the second compressed rubber layer, the rubber component exemplified as the rubber component (A) of the first compressed rubber layer can be used, and a preferred embodiment is also the first compressed rubber layer. It is the same as the rubber component (A) of.

The vulcanized rubber composition of the second compressed rubber layer may further contain a filler in addition to the rubber component. As the filler, the filler exemplified as the filler (C) of the first compressed rubber layer can be used, and the preferred embodiment and the ratio of carbon black in the filler are the same as those of the filler (C) of the first compressed rubber layer.

In the second compressed rubber layer, the ratio of the filler (particularly carbon black) is, for example, 5 to 80 parts by mass, preferably 10 to 60 parts by mass, and more preferably 15 to 50 parts by mass with respect to 100 parts by mass of the rubber component. In particular, it may be 20 to 40 parts by mass). If the proportion of the filler is too small, the elastic modulus may be insufficient and the lateral pressure resistance and durability may be lowered, and if it is too large, the elastic modulus may be too high and the fit with the pulley groove may be deteriorated. is there.

The vulcanized rubber composition of the second compressed rubber layer may further contain a plasticizer in addition to the rubber component. Examples of the plasticizer include an aliphatic carboxylic acid-based plasticizer (adipic acid ester-based plasticizer, sebacic acid ester-based plasticizer, etc.) and an aromatic carboxylic acid ester-based plasticizer (phthalic acid ester-based plasticizer, trimellitic acid). (Ester-based plasticizer, etc.), oxycarboxylic acid ester-based plasticizer, phosphoric acid ester-based plasticizer, ether-based plasticizer, ether ester-based plasticizer, and the like. These plasticizers can be used alone or in combination of two or more. Of these, ether ester plasticizers are preferred.

The ratio of the plasticizer is, for example, 1 to 30 parts by mass, preferably 3 to 20 parts by mass, and more preferably 3 to 10 parts by mass (particularly 3 to 8 parts by mass) with respect to 100 parts by mass of the rubber component.

The vulcanized rubber composition of the second compressed rubber layer may further contain short fibers and other additives in addition to the rubber component. As the short fiber, the short fiber exemplified as the short fiber (B) of the first compressed rubber layer can be used, and as another additive, it is exemplified as another additive (D) of the first compressed rubber layer. Additives are available. Of these, the second compressed rubber layer preferably contains a vulcanizing agent or a cross-linking agent, a vulcanization accelerator, a processing agent or a processing aid, and an antiaging agent in addition to the rubber component.

The ratio of the metal oxide as a vulcanizing agent is, for example, 1 to 20 parts by mass, preferably 3 to 17 parts by mass, and more preferably 5 to 15 parts by mass (particularly 7 to 13 parts by mass) with respect to 100 parts by mass of the rubber component. Department).

The ratio of the vulcanization accelerator is, for example, 0.1 to 15 parts by mass, preferably 0.3 to 10 parts by mass (for example, 0.5 to 5 parts by mass) with respect to 100 parts by mass of the rubber component in terms of solid content. , More preferably 0.5 to 3 parts by mass (particularly 0.5 to 1.5 parts by mass).

The ratio of the processing agent or processing aid (such as stearic acid) is, for example, 10 parts by mass or less (for example, 0 to 5 parts by mass), preferably 0.1 to 3 parts by mass, more preferably 0.1 part by mass, based on 100 parts by mass of the rubber component. Is about 0.3 to 2 parts by mass (particularly 0.5 to 1.5 parts by mass).

The ratio of the anti-aging agent is, for example, 0.5 to 15 parts by mass, preferably 1 to 10 parts by mass, and more preferably 2.5 to 7.5 parts by mass (particularly 3 to 7) with respect to 100 parts by mass of the rubber component. (Mass part).

[Stretch rubber layer]
As described above, the rubber hardness of the stretched rubber layer is higher than the rubber hardness of the second compressed rubber layer and lower than the rubber hardness of the first compressed rubber layer.

The rubber hardness Hs of the stretched rubber layer can be selected from the range of, for example, about 75 to 95 °, for example, 80 to 93 ° (for example, 85 to 90 °), preferably 86 to 90 °, and more preferably 88 to 90 °. .. If the rubber hardness is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

The tensile elastic modulus (modulus) of the stretched rubber layer is, for example, 15 to 30 MPa, preferably 17 to 28 MPa, and more preferably 20 to 27 MPa in the belt width direction. If the tensile elastic modulus is too small, the lateral pressure resistance may decrease, and if it is too large, the hardness may be too high and the fit with the pulley groove may decrease.

The average thickness of the stretched rubber layer is, for example, 0.5 to 10 mm (for example, 0.5 to 1.5 mm), preferably 0.6 to 5 mm, and more preferably 0.7 to 3 mm (particularly 0.8 to 1 mm). There may be.

The stretched rubber layer may be formed of a vulcanized rubber composition commonly used as a rubber composition of a wrapped V-belt. The vulcanized rubber composition may be a vulcanized rubber composition containing a rubber component, and the rubber hardness of the stretched rubber layer and the like can be adjusted by appropriately adjusting the composition of the composition. The method for adjusting the rubber hardness and the like is not particularly limited, and the composition and / or type of the components constituting the composition may be changed and adjusted. From the viewpoint of convenience and the like, the ratio of short fibers and fillers and / Alternatively, it is preferable to change the type for adjustment.

As the rubber component constituting the vulcanized rubber composition forming the stretched rubber layer, the rubber component exemplified as the rubber component (A) of the first compressed rubber layer can be used, and a preferred embodiment is also the rubber of the first compressed rubber layer. It is the same as the component (A).

The vulcanized rubber composition of the stretched rubber layer may further contain short fibers in addition to the rubber component. As the short fibers, the short fibers exemplified as the short fibers (B) of the first compressed rubber layer can be used, and the preferred embodiment and the ratio to the rubber component are the same as those of the short fibers (B) of the first compressed rubber layer.

The vulcanized rubber composition of the stretched rubber layer may further contain a filler. As the filler, the filler exemplified as the filler (C) of the first compressed rubber layer can be used, and the preferred embodiment and the ratio of carbon black in the filler are the same as those of the filler (C) of the first compressed rubber layer.

In the stretched rubber layer, the ratio of the filler (particularly carbon black) is, for example, 5 to 100 parts by mass, preferably 10 to 80 parts by mass, and more preferably 20 to 60 parts by mass (particularly 30) with respect to 100 parts by mass of the rubber component. ~ 50 parts by mass). If the proportion of the filler is too small, the elastic modulus may be insufficient and the lateral pressure resistance and durability may be lowered, and if it is too large, the elastic modulus may be too high and the fit with the pulley groove may be deteriorated. is there.

The vulcanized rubber composition of the stretched rubber layer may further contain other additives in addition to the rubber component. As the other additive, the other additive exemplified as the other additive (D) of the first compressed rubber layer can be used, and the preferred embodiment and the ratio to the rubber component are also the other additive of the first compressed rubber layer. It is the same as (D).

[Core layer]
The core wires included in the core layer are usually twisted cords arranged at predetermined intervals in the belt width direction. The core wires are arranged so as to extend in the longitudinal direction of the belt, and a plurality of core wires parallel to the longitudinal direction may be arranged, but from the viewpoint of productivity, they are usually arranged substantially parallel to the longitudinal direction of the belt. It extends in parallel at a predetermined pitch and is arranged in a spiral shape. When arranged in a spiral shape, the angle of the core line with respect to the longitudinal direction of the belt may be, for example, 5 ° or less, and is preferably closer to 0 ° from the viewpoint of belt travelability.

The core layer may include core wires having an adjusted arrangement density, and may be a core layer formed only of core wires as described above, but it suppresses peeling between layers and belts. From the viewpoint of improving durability, a core layer (adhesive rubber layer) formed of a vulcanized rubber composition in which a core wire is embedded is preferable. The core layer formed of the vulcanized rubber composition in which the core wire is embedded is usually called an adhesive rubber layer, and the core wire is embedded in the layer formed of the vulcanized rubber composition containing a rubber component. Has been done. The adhesive rubber layer is interposed between the stretch rubber layer and the compressed rubber layer (particularly the first compressed rubber layer) to bond the stretch rubber layer and the compressed rubber layer, and a core wire is embedded in the adhesive rubber layer. There is. The form in which the core wire is embedded is not particularly limited, and it is sufficient that a part of the core wire is embedded in the adhesive rubber layer, and the durability can be improved. A form in which the whole is completely embedded in the adhesive rubber layer) is preferable.

In the present invention, by adjusting the arrangement density of the core wires in the core body layer, it is possible to improve the overturning resistance in severe multiple layout applications.

That is, FIG. 3 is a drawing showing the belt width W, the core wire diameter D, the core wire spacing d, and the core wire pitch P in the wrapped V belt of the present invention, but as shown in FIG. 3, an adhesive rubber layer is provided. In the belt 1, the core wires 3 are arranged in the core layer 4 at a predetermined interval d in the belt width direction, and by adjusting this interval d, the overturning resistance can be improved. Specifically, the ratio X (%) of the "total value of the intervals d" to the "belt width W" is adjusted, and in this interval d, in addition to the intervals between the adjacent core lines 3, the core lines 3 at both ends are used. The distance from the end of the belt (not including the outer cover 6) (d at both ends in FIG. 3) is also included. The belt end is a belt end that does not include the outer cover 6, and means an end on a line connecting the centers of the core wires 3. Further, in FIG. 3, the belt end portion is the end portion of the core body layer 4, which is the adhesive rubber layer, but in the belt which does not have the adhesive rubber layer and the core wire independently forms the core body layer, The stretch layer and the compressed rubber layer correspond to the end of the belt.

That is, in the present application, the total value of the interval d means a value obtained by subtracting the value of "total core wire diameter D (core wire diameter D x number of core wires)" from the value W of the "belt width". Therefore, the ratio X can be replaced with a relational expression of the core wire diameter D and the core wire pitch P as shown in the following equation.
X = (total of intervals d / belt width W) x 100
= [(Total of belt width W-core wire diameter D) / belt width W] x 100
= {[Belt width W- (core wire diameter D x number of core wires)] / belt width W} x 100
= "{Belt width W- [Core wire diameter D x (Belt width W / Core wire pitch P)]} / Belt width W" x 100
= [1- (Core wire diameter D / Core wire pitch P)] × 100.

In the present application, the belt width W, the core wire diameter D, the interval d, and the core wire pitch P are obtained based on a cross-sectional view (cross-sectional view) perpendicular to the length direction of the belt, and the core wire pitch P is shown in FIG. As shown in 3, it is the distance between the centers of adjacent core lines in the cross-sectional view.

The core wire diameter D means the average wire diameter of the core wire (fiber diameter of the twisted cord). The core wire diameter D may be, for example, 0.5 to 3 mm, preferably 1 to 2.5 mm, more preferably 1.5 to 2.3 mm, and more preferably 1.7 to 2.1 mm (particularly 1). It is about 0.8 to 2 mm). If the core wire diameter D is too small, the lateral pressure resistance of the belt is lowered, buckling deformation occurs, and the belt may overturn. On the other hand, if the core wire diameter D is too large, the flexibility of the belt is lowered, so that the wrapability around the pulley is lowered and the belt may capsize.

As described above, the core line pitch P means the distance between the centers of adjacent core lines embedded in a spiral from one end to the other end in the belt width direction of the core body layer. The core line pitch P is, for example, 1 to 3.5 mm, preferably 1.2 to 3 mm, and more preferably 1.5 to 2.5 mm (particularly 1.9 to 2.3 mm). The core line pitch P is usually selected from such a range so that the core lines are arranged at equal intervals. If the core line pitch P is too small, the flexibility of the belt is lowered, so that the wrapping property around the pulley is lowered and the belt may capsize. On the other hand, if the core wire pitch P is too large, the lateral pressure resistance of the belt is lowered, buckling deformation occurs, and the belt may overturn.

In the present application, as shown in FIG. 3, the number of core wires means an apparent number of core wires arranged at a predetermined core wire pitch P in the belt width direction in a cross-sectional view. That is, the number of core wires means the number of spirals when one core wire is embedded in a spiral shape. However, in reality, since the core wire is embedded in a spiral shape, the arrangement mode of the core wire 3 differs depending on the portion of one endless wrapped V-belt 1 whose cross section is to be collected. Therefore, practically, when each core line pitch P is a constant value in the range of 1 to 3.5 mm, the value after the decimal point is rounded down from the calculated value obtained by dividing the belt width by the core line pitch P. The value is regarded as an approximate "number of core lines" (effective number).

Specifically, in the present application, the ratio X can be measured based on the above formula: X = [1- (core wire diameter D / core wire pitch P)] × 100.

For example, when the core wire diameter D is 1.81 mm, Table 1 shows the relationship between the core wire pitch P, the interval d, and the ratio X of the total value of d to the belt width W.

The smaller the ratio X, the smaller the distance d between the core lines, which means that the arrangement density of the core lines is high, and conversely, the larger the ratio X, the lower the arrangement density of the core lines.

In the present invention, this proportion X is 5 to 17% (eg 5 to 16%), for example 5 to 15%, preferably 5.5 to 13%, more preferably 6 to 12% (eg 7 to 12%). ), More preferably about 6 to 10% (particularly 6.5 to 8%). If the ratio X is too small, the core wire arrangement becomes too dense, which reduces the flexibility of the belt and reduces the wrapping property around the pulley, and also makes it difficult for rubber to penetrate between the core wires. Is not fixed and easily peels off, resulting in non-uniform tension, which may cause the belt to overturn. On the other hand, if the ratio X is too large, the core wire arrangement becomes too sparse, so that the lateral pressure resistance of the belt is lowered, buckling deformation occurs, and the belt may capsize.

As the core wire, a twisted cord using a multifilament yarn (for example, various twists, single twist, rung twist, etc.) can be usually used.

Examples of the fibers constituting the core wire include polyolefin fibers (polyethylene fiber, polypropylene fiber, etc.), polyamide fibers (polyamide 6 fiber, polyamide 66 fiber, polyamide 46 fiber, aramid fiber, etc.), and polyester fiber (polyalkylene allylate type). _{Fibers) [Poly C 2-4} alkylene-C _6-14 allylate fibers such as polyethylene terephthalate (PET) fibers and polyethylene naphthalate (PEN) fibers], vinylon fibers, polyvinyl alcohol fibers, polyparaphenylene benzobisoxazole Synthetic fibers such as (PBO) fibers; natural fibers such as cotton, hemp, and wool; inorganic fibers such as carbon fibers are widely used. These fibers can be used alone or in combination of two or more.

Among these fibers, in terms of high modulus, polyester fibers ethylene terephthalate, a _{C 2-4} alkylene _{-C 6-12} arylate such as ethylene-2,6-naphthalate as a main constituent unit (polyalkylene arylate-series fiber) , Synthetic fibers such as polyamide fibers (aramid fibers, etc.), inorganic fibers such as carbon fibers, etc. are widely used, and polyester fibers (particularly polyethylene terephthalate fibers, polyethylene naphthalate fibers), polyamide fibers (particularly aramid fibers) are used. preferable.

The fiber may be a multifilament yarn. The fineness of the multifilament yarn may be, for example, about 2000 to 10000 denier (particularly 4000 to 8000 denier). The multifilament yarn may contain, for example, about 100 to 5000 monofilament yarns, preferably 500 to 4000 yarns, and more preferably 1000 to 3000 monofilament yarns.

When the core wire is embedded in the adhesive rubber layer, the core wire may be surface-treated in order to improve the adhesiveness with the vulcanized rubber composition forming the adhesive rubber layer. Examples of the surface treatment agent include surface treatment agents exemplified as the surface treatment agent for the short fibers of the first compressed rubber layer. The surface treatment agent may be treated alone or in combination of two or more, or may be sequentially treated with the same or different surface treatment agents a plurality of times. The core wire is preferably bonded with at least an RFL solution.

(Adhesive rubber layer)
The rubber hardness Hs of the vulcanized rubber composition forming the adhesive rubber layer is, for example, 72 to 80 °, preferably 73 to 78 °, and more preferably 75 to 77 °. If the rubber hardness is too small, the lateral pressure resistance may decrease, and if it is too large, the vulcanized rubber composition around the core wire becomes rigid and the core wire becomes difficult to bend, and the adhesive rubber layer There is a risk that the core wire will peel off due to heat generation deterioration (cracking), bending fatigue of the core wire, and the like.

As the rubber component constituting the vulcanized rubber composition forming the adhesive rubber layer, the rubber component exemplified as the rubber component (A) of the first compressed rubber layer can be used, and a preferred embodiment is also the rubber of the first compressed rubber layer. It is the same as the component (A).

The vulcanized rubber composition of the adhesive rubber layer may further contain a filler in addition to the rubber component. As the filler, the filler exemplified as the filler (C) of the first compressed rubber layer can be used, and the preferred embodiment and the ratio of carbon black in the filler are the same as those of the filler (C) of the first compressed rubber layer.

In the adhesive rubber layer, the ratio of the filler is, for example, 1 to 100 parts by mass, preferably 10 to 80 parts by mass, and more preferably 30 to 70 parts by mass (particularly 40 to 60 parts by mass) with respect to 100 parts by mass of the rubber component. It may be. The ratio of carbon black may be, for example, 1 to 50 parts by mass, preferably 10 to 45 parts by mass, and more preferably 20 to 40 parts by mass with respect to 100 parts by mass of the rubber component.

The vulcanized rubber composition of the adhesive rubber layer may further contain a plasticizer in addition to the rubber component. As the plasticizer, the plasticizer exemplified as the plasticizer of the second compressed rubber layer can be used, and the preferred embodiment and the ratio to the rubber component are the same as those of the plasticizer of the second compressed rubber layer.

The vulcanized rubber composition of the adhesive rubber layer may further contain short fibers and other additives in addition to the rubber component. As the short fiber, the short fiber exemplified as the short fiber (B) of the first compressed rubber layer can be used, and as another additive, it is exemplified as another additive (D) of the first compressed rubber layer. Additives are available. Of these, the adhesive rubber layer preferably contains a vulcanization agent or a cross-linking agent, a vulcanization accelerator, a processing agent or a processing aid, and an antiaging agent in addition to the rubber component. The ratio of these additives to the rubber component is the same as that of the second compressed rubber layer.

The average thickness of the adhesive rubber layer is, for example, 0.2 to 5 mm, preferably 0.5 to 4 mm, and more preferably 1 to 3.5 mm (particularly 2 to 3 mm).

[Outer cloth]
The outer cover cloth (cover cloth) is made of a conventional cloth. Examples of the cloth include woven cloth, knitted cloth (weft knitted cloth, warp knitted cloth), and cloth materials such as non-woven fabric. Of these, woven fabrics woven in the form of plain weave, twill weave, red weave, etc., woven fabrics and knitted fabrics woven at a wide angle of more than 90 ° and 120 ° or less at the intersection angle of warp and weft are preferable. Woven cloth that is widely used as a cover cloth for transmission belts for general industry and agricultural machinery [plain woven cloth in which the crossing angle between the warp and weft is perpendicular, and the crossing angle between the warp and weft exceeds 90 ° and 120 °. The following wide-angle plain woven cloth (wide-angle canvas)] is particularly preferable. Further, in applications where durability is required, a wide-angle canvas may be used.

Examples of the fibers constituting the fabric include polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), polyamide fibers (polyamide 6 fibers, polyamide 66 fibers, polyamide 46 fibers, aramid fibers, etc.), and polyester fibers (polyalkylene allylate). Synthetic fibers such as vinyl alcohol fibers (polyvinyl alcohol fibers, ethylene-vinyl alcohol copolymer fibers, vinylon fibers, etc.), polyparaphenylene benzobisoxazole (PBO) fibers; cellulose fibers (cellulose fibers, etc.) Natural fibers such as wool (such as fibers of cellulose derivatives); inorganic fibers such as carbon fibers are widely used. These fibers may be single yarns used alone, or may be blended yarns in which two or more kinds are combined.

Among these fibers, a blended yarn of a polyester fiber and a cellulosic fiber is preferable from the viewpoint of excellent mechanical properties and economic efficiency.

The polyester fiber may be a polyalkylene allylate fiber. _{Examples of the polyalkylene allylate fiber include poly C 2-4} alkylene-C _8-14 allylate fiber such as polyethylene terephthalate (PET) fiber and polyethylene naphthalate (PEN) fiber.

Cellulose-based fibers include cellulosic fibers (cellulosic fibers derived from plants, animals, bacteria, etc.) and fibers of cellulosic derivatives. Examples of cellulose fibers include wood pulp (coniferous tree, broadleaf tree pulp, etc.), bamboo fiber, sugar cane fiber, seed hair fiber (cotton fiber (cotton linter), capoc, etc.), ginseng fiber (hemp, kozo, mitsumata, etc.), Examples thereof include natural plant-derived cellulose fibers (pulp fibers) such as leaf fibers (Manila hemp, New Zealand hemp, etc.); animal-derived cellulose fibers such as squirrel cellulose; bacterial cellulose fibers; and algae cellulose. Examples of the fibers of the cellulose derivative include cellulose ester fibers; regenerated cellulose fibers (rayon, cupra, lyocell, etc.).

The mass ratio of the polyester fiber to the cellulosic fiber is, for example, the former / the latter = 90/10 to 10/90, preferably 80/20 to 20/80, and more preferably 70/30 to 30/70 (particularly 60/70). 40-40 / 60).

The average fineness of the fibers constituting the fabric is, for example, 5 to 30 counts, preferably 10 to 25 counts, and more preferably 10 to 20 counts.

The basis weight of the cloth (raw material cloth) is, for example, 100 to 500 g / m ² , preferably 200 to 400 g / m ² , and more preferably 250 to 350 g / m ² .

When the cloth (raw material cloth) is a woven cloth, the thread density (density of warp and weft) of the cloth is, for example, 60 to 100 threads / 50 mm, preferably 70 to 90 threads / 50 mm, and more preferably 75 to 85 threads / 50 mm. Is.

The outer cover may be a single layer or a multi-layer (for example, 2 to 5 layers, preferably 2 to 4 layers, more preferably 2 to 3 layers), but from the viewpoint of productivity and the like, it may be a single layer. Layers (1 ply) or 2 layers (2 plies) are preferred.

The outer cover cloth may be a cloth to which a rubber component is attached in order to improve the adhesiveness with the belt body. The outer cloth to which the rubber component is attached is a cloth that has undergone an adhesive treatment such as a treatment of soaking (immersing) a rubber glue in which a rubber composition is dissolved in a solvent, or a treatment of friction (rubbing) a solid rubber composition. It may be. The bonding treatment may be performed by treating at least one surface of the fabric, and it is preferable to treat at least the surface in contact with the belt body.

As the rubber component constituting the rubber composition to be adhered to the outer cover, the rubber component exemplified as the rubber component (A) of the first compressed rubber layer can be used, and the preferred embodiment is also the rubber component (A) of the first compressed rubber layer. ) Is the same.

The rubber composition to be attached to the outer cover may further contain a filler in addition to the rubber component. As the filler, the filler exemplified as the filler (C) of the first compressed rubber layer can be used, and the preferred embodiment and the ratio of carbon black in the filler are the same as those of the filler (C) of the first compressed rubber layer.

In the rubber composition to be attached to the outer cover, the ratio of the filler (particularly carbon black) is, for example, 5 to 80 parts by mass, preferably 10 to 75 parts by mass, and more preferably 30 to 70 parts by mass with respect to 100 parts by mass of the rubber component. It is a mass part (particularly 40 to 60 parts by mass).

The rubber composition to be attached to the outer cover may further contain a plasticizer in addition to the rubber component. As the plasticizer, the plasticizer exemplified as the plasticizer of the second compressed rubber layer can be used, and the preferred embodiment is the same as that of the plasticizer of the second compressed rubber layer.

In the rubber composition to be attached to the outer cover, the proportion of the plasticizer is, for example, 3 to 50 parts by mass, preferably 5 to 40 parts by mass, and more preferably 10 to 30 parts by mass (particularly) with respect to 100 parts by mass of the rubber component. 15 to 25 parts by mass).

The rubber composition to be attached to the outer cover may further contain short fibers and other additives in addition to the rubber component. As the short fiber, the short fiber exemplified as the short fiber (B) of the first compressed rubber layer can be used, and as another additive, it is exemplified as another additive (D) of the first compressed rubber layer. Additives are available. Of these, the rubber composition to be adhered to the outer cover preferably contains a vulcanization agent or a cross-linking agent, a vulcanization accelerator, a processing agent or a processing aid, and an antiaging agent in addition to the rubber component. The ratio of these additives to the rubber component is the same as that of the second compressed rubber layer.

The coefficient of friction of the outer cover, which is the transmission surface, is, for example, 0.9 to 1, preferably 0.91 to 0.96, and more preferably 0.92 to 0.95. In the present application, the coefficient of friction can be measured by the method described in Examples described later.

The average thickness of the outer cover (in the case of a multi-layer, the total average thickness of the entire multi-layer) is, for example, 0.4 to 2 mm, preferably 0.5 to 1.4 mm, and more preferably 0.6 to 1.2 mm. .. If the thickness of the outer cover is too thin, the wear resistance may be lowered, and if it is too thick, the bending resistance of the belt may be lowered.

[Reinforcing cloth layer]
The wrapped V-belt may further include a reinforcing cloth layer between the inner peripheral surface (inner peripheral side surface) of the compressed rubber layer and the outer covering cloth. FIG. 4 shows an example of the wrapped V-belt of the present invention provided with a reinforcing cloth layer. In this example, the wrapped V-belt 11 has an stretch rubber layer 12, an adhesive rubber layer 14 in which a core body (core wire) 13 is embedded, a first compressed rubber layer 15a, and a second compression, similarly to the wrapped V-belt of FIG. After providing the rubber layer 15b, unlike the wrapped V-belt of FIG. 2, a reinforcing cloth layer 17 is interposed between the second compressed rubber layer 15b and the outer cover cloth 16.

The reinforcing cloth layer is also formed of a conventional cloth in the same manner as the outer cloth. As the cloth, the cloth exemplified as the cloth of the outer cover can be used, and the preferred embodiment is the same as that of the outer cloth.

The reinforcing cloth layer may be a cloth to which a rubber component is attached in order to improve the adhesiveness with the compressed rubber layer and the outer cover cloth. The outer cloth to which the rubber component is attached is a cloth that has undergone an adhesive treatment such as a treatment of soaking (immersing) a rubber glue in which a rubber composition is dissolved in a solvent, or a treatment of friction (rubbing) a solid rubber composition. It may be. As the rubber composition, the rubber composition exemplified as the rubber composition of the outer cover can be used, and the preferred embodiment is the same as that of the outer cover. The adhesion treatment may be performed by treating at least one surface of the fabric, preferably at least the surface in contact with the compressed rubber layer, and particularly preferably both sides.

The reinforcing cloth layer may be a single layer or a multi-layer (for example, 2 to 5 layers, preferably 2 to 4 layers, more preferably about 2 to 3 layers), but from the viewpoint of productivity and the like. , Single layer (1 ply) or 2 layers (2 plies) are preferable.

The average thickness of the reinforcing cloth layer (in the case of a multi-layer, the total average thickness of the entire multi-layer) is, for example, 0.4 to 2 mm, preferably 0.5 to 1.4 mm, and more preferably 0.6 to 1.2 mm. is there. If the thickness of the reinforcing cloth layer is too thin, the effect of improving the crack resistance may decrease, and if it is too thick, the bending resistance of the belt may decrease.

[Manufacturing method of wrapped V-belt]
The wrapped V-belt can be manufactured by a conventional method, for example, the method described in JP-A-6-137381 and WO2015 / 104778 pamphlet.

Specifically, the wrapped V-belt is, for example, a laminate of an adhesive-treated reinforcing cloth and a sheet for an unvulcanized second compressed rubber layer and a sheet for a first compressed rubber layer obtained by rolling. Is cut and set in the mantle, the unvulcanized adhesive rubber layer sheet is wound on the first compressed rubber layer sheet, the core body is wound on the wound adhesive rubber layer sheet, and then the core body is wound. A winding step of winding an unvulcanized stretch rubber layer sheet on a core body, a cutting step of cutting (ring-cutting) the obtained annular laminate on the mantle, and combining the cut annular laminate into a pair of pulleys. It can be obtained through a skiving step in which the rubber is cut into a V shape while being bridged and rotated, and the obtained unvulcanized belt body is wrapped (coated) with an adhesive-treated outer cloth and vulcanized. In the vulcanization step, the vulcanization temperature can be selected according to the type of rubber component, for example, 120 to 200 ° C., preferably 150 to 180 ° C. The rubber layer sheets containing the short fibers can be arranged (oriented) in the rolling direction by a method such as rolling with a calendar roll or the like.

By combining the obtained wrapped V-belt with a drive pulley to which the wrapped V-belt can be mounted, the belt transmission device of the present invention can be manufactured.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. The raw materials used for the rubber composition, the method for preparing the rubber composition, the fiber materials used, the method for measuring or evaluating each physical property, and the like are shown below.

[Rubber composition raw material]
Chloroprene rubber: "PM-40" manufactured by DENKA Co., Ltd.
Magnesium oxide: "Kyowa Mag 30" manufactured by Kyowa Chemical Industry Co., Ltd.
Stearic acid: NOF CORPORATION "Stearic acid camellia"
Anti-aging agent: "Non-flex OD-3" manufactured by Seiko Chemical Co., Ltd.
Carbon Black: "Seast 3" manufactured by Tokai Carbon Co., Ltd.
Silica: Evonik Japan Co., Ltd., "ULTRASIL (registered trademark) VN3", BET specific surface area 175 m ² / g
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.
Naphthenic oil: "NS-900" manufactured by Idemitsu Kosan Co., Ltd.
N, N'-m-Phoenix Maleimide: "Barnock PM" manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Aramid short fiber: "Conex short fiber" manufactured by Teijin Co., Ltd., average fiber length 3 mm, average fiber diameter 14 μm, RFL solution (2.6 parts of resorcin, 1.4 parts of 37% formalin, vinylpyridine-styrene-butadiene) Short fiber with 6% by mass of solid content adhered with polymer latex (17.2 parts manufactured by Nippon Zeon Co., Ltd., 78.8 parts water) Polyester short fiber: Teijin Co., Ltd., average short fiber Length 3 mm.

[Core line]
Aramid fiber twisted cord, average wire diameter 1.81 mm or 1.99 mm.

[Adhesive rubber layer, rubber composition for friction rubber]
The rubber composition A having the composition shown in Table 2 was kneaded with a Banbury mixer, and the kneaded rubber was passed through a calendar roll to prepare an adhesive rubber layer sheet as an unvulcanized rolled rubber sheet having a predetermined thickness. Further, the rubber composition B shown in Table 2 was kneaded with a Banbury mixer to prepare a massive unvulcanized rubber composition for friction. Further, Table 2 also shows the results of measuring the hardness and tensile elastic modulus of the vulcanized product of each rubber composition.

[Rubber composition for stretch rubber layer, first compression rubber layer and second compression rubber layer]
The rubber compositions C to G having the formulations shown in Tables 3 and 4 are kneaded with a Banbury mixer, and the kneaded rubber is passed through a calendar roll to form an unvulcanized rolled rubber sheet having a predetermined thickness, which is a stretch rubber layer sheet. A sheet for the compressed rubber layer and a second compressed rubber layer were prepared, respectively (Table 4 shows only the sheet for the second compressed rubber layer). Further, the results of measuring the hardness and tensile elastic modulus of the vulcanized product of each rubber composition are also shown in Tables 3 and 4.

[Rubber hardness Hs of vulcanized rubber]
Each rubber layer sheet was press-vulcanized at a temperature of 160 ° C. for 30 minutes to prepare a vulcanized rubber sheet (thickness of 100 mm × 100 mm × 2 mm). A laminate of three vulcanized rubber sheets was used as a sample, and the hardness was measured using a durometer A type hardness tester according to JIS K6253 (2012). For the bulk unvulcanized rubber composition B for friction, a test piece was sampled from the bulk rubber and passed through a calendar roll to prepare an unvulcanized rolled rubber sheet having a predetermined thickness.

[Tensile modulus of vulcanized rubber (modulus)]
Using the vulcanized rubber sheet prepared for measuring the rubber hardness Hs of the vulcanized rubber as a sample, a test piece punched into a dumbbell shape was prepared according to JIS K6251 (1993). In the sample containing short fibers, the samples were punched out in a dumbbell shape so that the arrangement direction (columnar direction) of the short fibers was the tensile direction. Then, both ends of the test piece were grasped with chucks (grasping tools), and when the test piece was pulled at a speed of 500 mm / min, the tensile stress (tensile elastic modulus) until the test piece was cut was measured.

[Woven cloth for outer cover and reinforcing cloth layer]
Woven fabric of a blended yarn of polyester fiber and cotton (polyester fiber / cotton = 50/50 mass ratio) (120 ° wide angle weave, 20th fineness warp and 20th weft, warp and weft yarn density 75 / 50mm , 280 g / m ² ) is passed at the same time as the rubber composition B and the woven fabric between the rolls having different surface speeds of the calendar rolls using the rubber composition B in Table 2, and between the weaves of the woven fabric. The reinforced cloth precursor and the outer cloth precursor were prepared by friction treatment (performed once for each of the front and back sides of the woven fabric) by rubbing the rubber composition B up to.

[Belt friction coefficient]
As shown in FIG. 5, the coefficient of friction of the belt is such that one end of the cut belt 21 is fixed to the load cell 22, a load 23 of 3 kgf is placed on the other end, and the winding angle of the belt around the pulley 24 is adjusted. The belt 21 was wound around the pulley 24 at 45 °. Then, the belt 21 on the load cell 22 side was pulled at a speed of 30 mm / sec for about 15 seconds, and the average friction coefficient of the friction transmission surface (outer coat) was measured. At the time of measurement, the pulley 24 was fixed so as not to rotate.

[Belt running test]
Using the wrapped V-belts obtained in Examples, Comparative Examples and Reference Examples, as shown in FIG. 6, a drive (Dr) pulley having a diameter of 175 mm, an idler (Id) pulley having a diameter of 80 mm, and a driven (Dn1) having a diameter of 150 mm are used. ) Pulley, 162 mm diameter driven (Dn2) pulley, 140 mm diameter driven (Dn3) pulley, 80 mm diameter tension (Ten1) pulley, 127 mm diameter driven (Dn4) pulley, 70 mm diameter tension (Ten2) pulley, 70 mm diameter Using a multi-axis layout tester equipped with an auto tension (A / Ten) pulley (auto tensioner), the belt was run under the conditions shown in Table 5, and the side surface of the belt at a running time of 0.6 to 1 hour. The temperature was measured and the time during which the belt overturned occurred was evaluated.

The belt transmission device of the present invention is not limited to a single belt transmission device, and may be a belt transmission device having two or more belt transmission devices. , It is carried out with one belt, which is a harsh condition. Therefore, in the present application, in the method for measuring the lateral pressure deformation index, the belt transmission device to be measured is a single belt transmission device.

Examples 1 to 15, Comparative Examples 1 to 6 and Reference Examples 1 to 4
A laminate of the reinforcing cloth precursor, the sheet for the second compressed rubber layer shown in Tables 7 to 9, and the sheet for the first compressed rubber layer shown in Tables 7 to 9 is cut on the outer peripheral surface of the cylindrical drum. After mounting, the adhesive rubber layer sheet, the core wire, and the stretch rubber layer sheet shown in Tables 7 to 9 are sequentially laminated and attached, and the reinforcing cloth precursor, the unvulcanized rubber layer, and the core wire are attached. Formed a tubular unvulcanized sleeve in which The obtained unvulcanized sleeve was cut in the circumferential direction while being arranged on the outer periphery of the cylindrical drum to form an annular unvulcanized rubber belt. In the stretch rubber layer and the first compression rubber layer, short fibers were arranged in the belt width direction.

Next, the unvulcanized rubber belt was removed from the drum, and both side surfaces of the unvulcanized rubber belt were cut (skived) at a predetermined angle to form a V-shaped cross section of the unvulcanized rubber belt. As shown in FIG. 4, an unvulcanized rubber belt having a V-shaped cross section (stretch rubber layer 12, adhesive rubber layer 14 in which a core body (core wire) 13 is embedded, a first compressed rubber layer 15a, a second compressed rubber layer). A belt made of 15b and the reinforcing cloth layer 17) was subjected to a cover-wrapping treatment in which the periphery thereof was covered with an outer cloth precursor to form an unvulcanized belt molded body.

The obtained unvulcanized belt molded body was inserted into the concave groove of the ring mold. Further, in a state where a cylindrical rubber sleeve is fitted on the outer peripheral surface of the ring mold and the unvulcanized belt molded body, they are stored in a vulcanization can and vulcanized at a vulcanization temperature of 160 ° C. Got The obtained vulcanization belt was removed from the ring mold to obtain a wrapped V-belt.

As for the shape of the belt (belt type), as shown in Table 7, the thickness of the B type (JIS B, cross-sectional dimensions: width 16.5 mm x thickness 11.0 mm, belt length 158 inches) and B type are thinned. LB type (cross-sectional dimensions: width 16.5 mm x thickness 9.8 mm, belt length 158 inches), C-type (JIS C, cross-sectional dimensions: width 22.0 mm x thickness 14.0 mm, belt length 158) Inch) and LC type (cross-sectional dimensions: width 21.7 mm x thickness 11.4 mm, belt length 158 inches), which is a thinned C type, were produced. In the LB type, the ratio of each layer is the same as that of the B type, and the thickness of the LC type is the same.

The laminated structure of the wrapped V-belts obtained in Example 1 is shown in FIG. 7. Each layer from the outer coating on the outer peripheral side to the outer coating on the inner peripheral side has thicknesses A to G. In FIG. 7, the reinforcing cloth layer having a thickness F is formed by stacking two reinforcing cloth precursors. Further, the outer cover is also covered with two outer coat precursors stacked on top of each other, but as shown in FIG. 7, two outer coats having a thickness G on the inner peripheral side of the belt are stacked (two-layer structure). On the other hand, since the outer cover precursors overlap on the outer peripheral side of the belt, the outer cover on the outer peripheral side having the thickness A has three layers (three-layer structure). Table 6 shows the results of summarizing the thickness of each layer.

Moreover, when the friction coefficient of the wrapped V-belt obtained in Example 1 was measured, it was 0.93.

Further, the lateral pressure deformation index of the belt transmission device provided with the wrapped V-belt obtained in Examples, Comparative Examples and Reference Examples measures the effective tension, the contact area between the drive pulley and the belt, and the aspect ratio by the following methods. And calculated.

[Effective tension (Te)]
The effective tension (Te) was determined as the difference between the tension on the tension side (Tt: the tension on the side where the belt faces the drive pulley) and the tension on the loose side (Ts: the tension on the side where the belt faces the driven pulley). The tension side tension Tt was measured by the tension measuring mechanism provided in the idler (Id) pulley shown in FIG. 6, and the loosening side tension Ts was measured by the tension measuring mechanism provided in the auto tension (A / Ten).

[Contact area between drive pulley and belt]
The area of the portion where the belt comes into contact with the drive (Dr) pulley is the total area of the contact areas of both side surfaces when the belt is wound at a predetermined winding angle, and is approximately calculated by the following method.

In the state of being wound around the pulley, the shape of the contact surface is actually "fan-shaped", but for convenience, the arc portion of the fan is regarded as a straight line and the area is calculated as a "rectangle".

Contact area on one side = Rectangular area = [Contact length in the circumferential direction (length regarded as a straight line)] x (Contact length in the radial direction)
= [Length of the arc part of the fan (length regarded as a straight line)] × (contact length in the radial direction)

In the above equation, the length of the arc portion of the fan is short on the inner peripheral side and long on the outer peripheral side, and differs depending on the position in the thickness direction. ..

Specifically, the arc length at that position was calculated based on the reference position defined by the JIS standard described below. Specifically, in the JIS standard for general-purpose V-belts (JIS K 6323: 2008), depending on the shape of the belt (M, A, B, C, D), the reference width called the "datum width" of the corresponding pulley is used. The corresponding position is defined as the reference position. FIG. 8 shows a schematic cross-sectional view of the B-shaped belt 30 attached to the Dr pulley 31, and the reference position is 5.5 mm (1/2 of the belt thickness) from the outer circumference of the Dr pulley 30. The datum width is 12.5 mm, which is the width of the pulley groove at this reference position. In FIG. 8, this reference position is a position at a depth of 6.16 mm from the outer peripheral surface of the belt 30, and the belt 30 projects 6.16-5.5 mm = 0.66 mm from the outer peripheral surface of the pulley 31. Therefore, the outer diameter of the DR pulley (the virtual outer diameter at the reference position for calculating the arc length) to which the B-shaped belt is attached is 175 mm- (5.5 mm × 2) = 164 mm. Further, as shown in FIG. 8, since the groove angle of the Dr pulley is 36 °, the contact area between the Dr pulley of the B-shaped belt and the belt can be calculated as follows.

Length of arc part of fan (reference position) = 164 x π x (Dr winding angle / 360)
Radial contact length = [11.0- (6.16-5.5)] / cos 18 ° = 10.87 mm
Contact area on both side surfaces = [164 × π × (Dr winding angle / 360)] × 10.87 × 2.

(Belt device equipped with C-shaped belt)
For C-shaped belts, the belt thickness is 14 mm, the reference position is at a depth of 7.85 mm from the outer peripheral surface of the belt, the datum width is 16.9 mm, and the virtual outer diameter of the Dr pulley is 175 mm- (7 mm x 2) = 161 mm. Therefore, the contact area between the Dr pulley of the C-shaped belt and the belt can be calculated as follows.

Length of arc part of fan (reference position) = 161 x π x (Dr winding angle / 360)
Radial contact length = [14.0- (7.85-7)] / cos 18 ° = 13.83 mm
Contact area on both side surfaces = [161 × π × (Dr winding angle / 360)] × 13.83 × 2.

(Belt device equipped with LB type belt)
For LB type belts, the belt thickness is 9.8 mm, the reference position is at a depth of 6.16 mm from the outer peripheral surface of the belt, the datum width is 12.5 mm, and the virtual outer diameter of the Dr pulley is 175 mm- (5.5 mm x). Since 2) = 164 mm, the contact area between the Dr pulley of the LB type belt and the belt can be calculated as follows.

Length of arc part of fan (reference position) = 164 x π x (Dr winding angle / 360)
Radial contact length = [9.8- (6.16-5.5)] / cos 18 ° = 9.62 mm
Contact area on both side surfaces = [164 × π × (Dr winding angle / 360)] × 9.62 × 2.

(Belt device equipped with LC type belt)
For LC type belts, the belt thickness is 11.4 mm, the reference position is at a depth of 7.85 mm from the outer peripheral surface of the belt, the datum width is 16.9 mm, and the virtual outer diameter of the Dr pulley is 175 mm- (7 mm x 2). Since = 161 mm, the contact area between the Dr pulley of the LC type belt and the belt can be calculated as follows.

Length of arc part of fan (reference position) = 161 x π x (Dr winding angle / 360)
Radial contact length = [11.4- (7.39-7)] / cos 18 ° = 11.58 mm
Contact area on both side surfaces = [161 × π × (Dr winding angle / 360)] × 11.58 × 2.

The Dr winding angle in Tables 10 to 14 is the angle of the portion where the belt winds and contacts the drive pulley (Dr), and means the central angle with respect to the arc in which the belt and the pulley are in contact. .. As a specific measurement method, a running layout for each condition was created as shown in FIG. 8 and calculated on the drawing. The Dr winding angle can be adjusted by changing the position of the idler (Id) pulley shown in FIG.

[aspect ratio]
The aspect ratio of the belt was calculated by dividing the upper width (width of the outer peripheral surface) of the obtained wrapped V-belt by the belt thickness.

Tables 10 to 14 show the results of evaluating the overturning resistance of the obtained wrapped V-belt.

As is clear from the results in Table 10, the belt transmission devices of Examples 1 to 4 have a lateral pressure deformation index of 0.49 or less and are excellent in overturning resistance, whereas the belt transmission devices of Comparative Examples 1 and 2 have excellent overturning resistance. The belt transmission device had a lateral pressure deformation index of more than 0.49, and capsized occurred early. In particular, Examples 1 and 3 to 4 having a lateral pressure deformation index of 0.12 to 0.41 were more excellent in overturning resistance than Example 2 having a lateral pressure deformation index of 0.49. Among them, in Example 1, the effective tension of the belt is high, and the balance of various characteristics such as lateral pressure resistance and durability is the best.

As is clear from the results in Table 11, the belt transmission device of Example 5 is an example in which the lateral pressure deformation index is adjusted to 0.45 with the effective tension as the effective tension between Examples 1 and 2, but withstand resistance. It was excellent in overturning property. On the other hand, although the effective tension is the same as that of Example 5, in Comparative Example 3 in which the contact area between the belt and the drive pulley is reduced by changing the winding angle around the drive pulley, the lateral pressure deformation index is 0.55. And capsized early.

As is clear from the results in Table 12, the belt transmission devices of Examples 6 to 8 are examples in which the aspect ratio is changed with respect to Example 1 and the lateral pressure deformation index is adjusted to 0.46 to 0.49. However, all of them were excellent in overturning resistance. On the other hand, the belt transmission devices of Comparative Examples 4 to 6 are examples in which the aspect ratio is changed as compared with Comparative Example 1, but the lateral pressure deformation index exceeds 0.49 in all of them, and they capsized at an early stage. ..

As is clear from the results in Table 13, in the belt transmission devices of Reference Examples 1 and 2, the relationship of rubber hardness does not satisfy "first compression rubber layer> stretch rubber layer", so that the temperature of the belt during running rises. Increased, and even with a lateral pressure deformation index of 0.41, it overturned early. On the other hand, the belt transmission devices of Examples 9 to 12 have the same resistance as that of Example 1 in which the rubber hardness of the first compressed rubber layer is 5 to 10 ° larger than the rubber hardness of the stretched rubber layer and 3 ° larger. It was excellent in overturning property.

As is clear from the results in Table 14, in Examples 13 to 15 in which the X value is in the range of 5 to 17%, the temperature rise of the belt during running is small, and the overturning resistance is as excellent as in Example 1. It was. On the other hand, in the belt transmission devices of Reference Examples 3 and 4, since the X value does not satisfy 5 to 17%, the temperature rise of the belt during running becomes large, and even if the lateral pressure deformation index is 0.41, it is within 100 hours. A capsize occurred.

The wrapped V-belt transmission device of the present invention can be used for general industrial machines such as compressors, generators and pumps, and agricultural machines such as combines, rice planters and mowers, and often repeats continuous bending accompanied by reverse bending. It has an axial layout and is suitable for agricultural machinery that requires a high horsepower of 8 PS or more / piece.

1,11 ... Wrapped V-belt 2,12 ... Stretch rubber layer 3,13 ... Core wire 4,14 ... Core layer (adhesive rubber layer)
5a, 15a ... 1st compression rubber layer 5b, 15b ... 2nd compression rubber layer 6,16 ... Outer cloth 17 ... Reinforcing cloth layer

Claims (6)

A core layer including core wires arranged at intervals in the belt width direction, an stretch rubber layer laminated on the outer peripheral side of the belt of the core layer, and a compressed rubber laminated on the inner peripheral side of the belt of the core layer. A belt transmission device including a wrapped V-belt including a layer and an outer cover covering the entire outer surface of the belt, and a drive pulley to which the wrapped V-belt can be mounted, and is a lateral pressure deformation index represented by the following formula. Is 0.1 to 0.49, a belt transmission device.
Lateral pressure deformation index = [effective tension (N / piece) / contact area between drive pulley and belt (mm ² )] x aspect ratio (in the formula, aspect ratio indicates belt top width / belt thickness) The belt transmission device according to claim 1, wherein the lateral pressure deformation index is 0.12 to 0.47. The belt transmission device according to claim 1 or 2, wherein the ratio X of the total value of the adjacent core wire intervals to the belt width in the core body layer is 5 to 17%. The compressed rubber layer includes a first compressed rubber layer laminated on the outer peripheral side of the belt and a second compressed rubber layer laminated on the inner peripheral side of the belt, and the rubber hardness of the stretched rubber layer is the second compressed rubber. The belt transmission device according to any one of claims 1 to 3, which is higher than the rubber hardness of the layer and lower than the rubber hardness of the first compressed rubber layer. The belt transmission device according to any one of claims 1 to 4, wherein the friction coefficient of the outer cover, which is the transmission surface, is 0.91 to 0.96. The belt transmission device according to any one of claims 1 to 5, wherein a reinforcing cloth layer is interposed between the inner peripheral surface of the compressed rubber layer and the outer cloth.

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