JPH10238596A - Belt for power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early prevent the occurrence of a crack, or rubber layer and cord separation, and improve a power transmission function at a high load by specifying the hardness of at least one of elongation and compressed rubber layers and the hardness of a bonded rubber layer. SOLUTION: A bonded rubber layer 6 is formed at approximately vertical center of a V-belt B, and a plurality of cords 7 are buried therein along a belt lengthwise direction approximately at equal breadthwise intervals. Also, each of the cores 7 is made of nylon, tetron or the like. Then, an elongation rubber layer 4, a compressed rubber layer 5 and a canvas layer 3 are laminated in order on the upper and lower surfaces of the bonded rubber layer 6. The canvas is made of cotton, nylon or the like. Also, rubber layers 4 to 6 are exposed to both lateral sides of the V-belt B, and the bottom of the V-belt B is formed to be cogged. In this case, the hardness Hs (JISA) of at least one of the rubber layers 4 and 5 is taken at a value between 90 and 96 degrees, while the rubber hardness Hs (JISA) of the rubber layer 6 is taken at a value between 83 and 89 degrees. According to this construction, the early occurrence of a crack, or each rubber layer and cord separation is restrained, and power transmission at a high load is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a transmission V-belt which can be used for high-load transmission such as a transmission for an automobile.

[0002]

2. Description of the Related Art Conventionally, V-belts, flat belts and toothed belts have been frequently used as power transmission belts for transmitting power. Of these, the flat belt is not suitable for high load transmission because it is slippery, while the toothed belt is not suitable for applications requiring slippage. For this reason, a V-belt is used in applications where high load transmission is possible and sliding is required.

[0003] This V-belt usually comprises an adhesive rubber layer in which a cord is embedded, and an expanded rubber layer and a compressed rubber layer which are respectively laminated on and under the adhesive rubber layer. And
This V-belt has a wrapped V-belt whose entire surface (entire circumference) is covered with canvas, and a side of the V-belt which has a canvas layer laminated on at least one of the upper surface of the stretched rubber layer and the lower surface of the compressed rubber layer. There are two types, a low-edge V-belt in which each of the rubber layers is exposed, and a low-edge type that can obtain a stable and high coefficient of friction is used for high load transmission.

[0004] However, it is impossible to transmit a high load only if the friction coefficient is stable. When the belt receives a lateral pressure from the pulley as a wedge effect when the belt is wound around the pulley, the lateral pressure is reduced. On the other hand, it is required to withstand without deformation. Therefore, conventionally, the rubber hardness (or elastic modulus) of the belt has been increased so as to withstand the lateral pressure from the pulley and maintain the initial V shape.

However, when the rubber hardness of the belt is increased, the bending stiffness increases, and when the diameter of the pulley is small, a transmission loss occurs or heat is generated, so that cracks caused by bending fatigue due to distortion occur early. Therefore, by forming the bottom surface of the low-edge V-belt in a cog shape, it is possible to maintain the lateral pressure resistance and improve the flexibility without lowering the high-load transmission capability.

In recent years, in order to further increase the rubber hardness and improve the lateral pressure resistance of this low edge cog V-belt, it is disclosed in, for example, JP-A-61-290255 and JP-A-61-290256. Thus, studies have been made on rubber compounding of the adhesive rubber layer and the stretched and compressed rubber layers.

[0007]

However, simply increasing the rubber hardness of each rubber layer to a specific rubber compound is not sufficient.
Depending on the combination of the hardness of the stretched or compressed rubber layer and the hardness of the adhesive rubber layer, separation of the stretched or compressed rubber layer, the adhesive rubber layer and the cord occurs, leading to a problem of early failure.

The present invention has been made in view of the above-mentioned points, and an object of the present invention is to provide an extended or compressed rubber layer for the low-edge cog V-belt, which withstands a side pressure from a pulley and performs transmission. By focusing on the relationship between the stretched or compressed rubber layer and the adhesive rubber layer responsible for bonding between the cords, it is possible to prevent the occurrence of cracks and separation of each rubber layer and the cord at an early stage, and to improve the lateral pressure resistance. The purpose is to improve the high load transmission capacity by improving the performance.

[0009]

In order to achieve the above object, according to the present invention, the rubber hardness of at least one of the stretched and compressed rubber layers is set to Hs (JIS A) = 90 to 96 °.
And the rubber hardness of the adhesive rubber layer is Hs (JIS A) =
The angle was set to 83 to 89 °.

Specifically, according to the first aspect of the present invention, an adhesive rubber layer in which a cord is embedded, an extension rubber layer and a compression rubber layer respectively laminated on upper and lower surfaces of the adhesive rubber layer, and the extension rubber layer It is assumed that the transmission V-belt is composed of a canvas layer laminated on at least one of the upper surface and the lower surface of the compressed rubber layer, and the rubber layers are exposed on both side surfaces and the bottom surface is formed in a cog shape.

The rubber hardness of at least one of the stretched and compressed rubber layers is Hs (JIS A) = 90-9.
6 °, and the rubber hardness of the adhesive rubber layer is Hs (JI
SA) = 83-89 °.

That is, if the rubber hardness of the stretched or compressed rubber layer for transmitting power is Hs (JISA) <90 °, the ability to withstand the lateral pressure from the pulley without deforming the shape, that is, the lateral pressure resistance, is obtained. On the other hand, when Hs (JIS A)> 96 °, bending fatigue is remarkably reduced, and cracks, extension or compression rubber layers, adhesive rubber layers and separation of cords are early. Hs (JIS A) = 90-96 °
And On the other hand, the rubber hardness of the adhesive rubber layer for bonding the extension and compression rubber layer to the cord is Hs (JIS A)
If it is> 89 °, the adhesion is remarkably reduced and separation occurs at an early stage, but Hs (JISA) <83 °
In the case of Hs (JIS), there is no transmission capacity to transmit the power transmitted by the stretched or compressed rubber layer to the cord due to too low elasticity, and the separation occurs at an early stage.
A) = 83-89 °. Therefore, an optimal combination of the stretched or compressed rubber layer and the adhesive rubber layer is obtained,
High load transmission capability can be improved while suppressing early generation of cracks and separation of each rubber layer and cord.

According to a second aspect of the present invention, in the first aspect of the present invention, the stretched and compressed rubber layer is made of chloroprene rubber.
Parts by weight, 40 to 60 parts by weight of a reinforcing filler, 1 to 20 parts by weight of a metal oxide vulcanizing agent of at least one kind of zinc oxide, magnesium oxide and lead oxide, and bismaleimide 2
It is made of rubber containing short fibers in which 10 to 10 parts by weight and aramid short fibers are blended, and the aramid short fibers are arranged in the belt width direction.

[0014] This makes it possible to effectively improve the lateral pressure resistance by increasing only the elastic modulus in the belt width direction, which is the arrangement direction of the short fibers, and to increase the belt elasticity in the belt longitudinal direction. Premature breakage can be prevented. Therefore, the high load transmission capacity and the durability life can be further improved.

According to a third aspect of the present invention, in the first or second aspect, the adhesive rubber layer comprises 100 parts by weight of chloroprene rubber, 30 to 50 parts by weight of a reinforcing filler, zinc oxide,
At least one kind of metal oxide vulcanizing agent of magnesium oxide and lead oxide, 1 to 20 parts by weight of silica, 5 to 30 parts by weight of silica, and 2 to 10 parts by weight of bismaleimide are each composed of a rubber. .

According to the present invention, the adhesive rubber layer can easily have Hs (JIS A) = 8 while maintaining various required properties.
The hardness can be as high as 3 to 89 °. Therefore,
An optimum high-load transmission V-belt can be easily obtained.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a transmission V-belt B according to an embodiment of the present invention, and an adhesive rubber layer 6 is provided at a substantially central portion in the vertical direction of the V-belt B. In the adhesive rubber layer 6, a plurality of cords 7, 7, ... are embedded so as to extend in the belt longitudinal direction at substantially equal intervals in the belt width direction. Each of the cords 7 may be of any type such as nylon, tetron, polyester or aramid fiber. Each code 7 is treated with resorcin-formalin-latex (RFL).

On the upper and lower surfaces of the adhesive rubber layer 6, an extension rubber layer 4 and a compression rubber layer 5 are laminated, respectively, and on the upper surface of the extension rubber layer 4 and the lower surface of the compression rubber layer 5, respectively.
Layered canvas layers 3, 3 are laminated. The canvas of each canvas layer 3 may be any fabric such as cotton, nylon or aramid fiber.

Both side surfaces of the V-belt B are not covered with canvas, the rubber layers 4 to 6 are exposed, and the bottom surface is formed in a cog shape. That is,
The V belt B is a so-called low edge cog type.

The stretched and compressed rubber layers 4 and 5 are composed of 100 parts by weight of chloroprene rubber, 40 to 60 parts by weight of a reinforcing filler, and vulcanized metal oxide of at least one of zinc oxide, magnesium oxide and lead oxide. 1 to 20 parts by weight of an agent, 2 to 10 parts by weight of bismaleimide, and rubber containing short fibers, each of which is mixed with aramid short fibers. The aramid short fibers are arranged in the belt width direction.

The chloroprene rubber may be either of a sulfur-modified type or a non-sulfur-modified type. In particular, the sulfur-modified type has a remarkable effect of increasing the crosslink density of bismaleimide, and is desirable.

If the amount of the metal oxide vulcanizing agent is less than 1 part by weight, crosslinking of the chloroprene rubber is not sufficiently performed, and the vulcanized matrix rubber is inferior not only in heat resistance but also in vulcanized physical properties. On the other hand, when the amount is more than 20 parts by weight, when the metal oxide is zinc oxide, the compounded dough falls down and becomes soft, and at the same time storage stability is deteriorated. When the metal oxide is magnesium oxide, the vulcanization rate becomes extremely slow. In the case of lead oxide, processing safety and storage stability are impaired, so the amount is 1 to 20 parts by weight. Particularly preferably, zinc oxide and magnesium oxide are used in combination, and the compounding amount is 3 to 8 parts by weight for 100 parts by weight of chloroprene rubber.

The bismaleimide is an N, N'-linked bismaleimide having two nitrogen atoms directly bonded and
Bismaleimides in which two nitrogen atoms are linked by an alkylene, cycloalkylene, oxydimethylene, phenylene, sulfone, or other divalent organic group. Specific examples of these include N, N'-ethylenebismaleimide, N, N'-hexamethylenebismaleimide, N, N '-(1.4-phenylene) dimaleimide,
N, N '-(o-phenylene) dimaleimide, N, N'
-(M-phenylene) dimaleimide, N, N '-(2.
4-tolylene) dimaleimide, N, N'-dulylenedimaleimide, N, N '-[4.4'(2.2'-dichlorobiphenylene)] dimaleimide, N, N '-[4.
4'-methylenediphenyl] dimaleimide, N, N'-
(1.4-Durylene diethylene) dimaleimide, N,
N '-[4.4'-sulfonyldiphenyl] dimaleimide, 2.6-bis (maleimidomethyl) -4-t-butylphenol, N, N'-oxydimethylenedimaleimide and the like.

If the amount of the bismaleimide is less than 2 parts by weight, the degree of crosslinking in the vulcanized product can be maintained while ensuring the processing safety of the unvulcanized product even when used in combination with the above metal oxide vulcanizing agent. On the other hand, if the amount is more than 10 parts by weight, bloom of bismaleimide will be recognized, so the amount is set to 2 to 10 parts by weight.

The amount of carbon black as the reinforcing filler is adjusted so that the elastic modulus of the matrix vulcanized rubber to which bismaleimide is not added is moderate, the viscosity of the matrix unvulcanized rubber is not too large, and the scorch time is safe for processing. It is determined to be able to maintain sex.

When the aramid short fiber length is shorter than 2 mm, the reinforcing property is inferior due to a small aspect ratio.
If the length is longer than 0 mm, the fibers are entangled with each other, resulting in poor dispersion in rubber or cutting during kneading. Therefore, the length is set to 2 to 10 mm, preferably 3 to 6 mm.
mm is better.

The aramid short fibers have been subjected to an adhesive treatment for imparting adhesiveness to chloroprene rubber. This adhesion treatment is a dipping treatment of aramid short fibers with an isocyanate compound or an epoxy compound (immersion → heating and drying)
Thereafter, dip processing is performed with an RFL solution, and thereafter, cutting is performed. Further, dip treatment (only once) with an isocyanate-based adhesive (for example, Chemlock 402 manufactured by Lord Corporation) may be performed. Further, the unvulcanized fiber may be cut into a predetermined length, then immersed in an adhesive treatment liquid, an excess liquid may be removed by centrifugation, and then heated and dried to perform the adhesion treatment.

If the amount of the aramid short fibers is too large, the bending fatigue (extension fatigue) in the longitudinal direction of the belt is significantly deteriorated.

The stretched and compressed rubber layers 4 and 5 have
Oil is blended to provide the matrix rubber with cold resistance or kneading processability.
If the amount is more than 5 parts by weight, the elastic modulus of the matrix rubber is lowered, and if the amount of carbon black is increased to compensate for this, the heat aging resistance and dynamic characteristics of the vulcanized rubber are deteriorated. It has been.

The rubber hardness of the expanded and compressed rubber layers 4 and 5 is set to Hs (JIS A) = 90 to 96 °.
That is, the rubber hardness is Hs (JIS A) <90.
°, the lateral pressure resistance, which indicates the ability to withstand the lateral pressure from the pulley without deforming the shape, is reduced, and the transmission capacity cannot be improved. On the other hand, Hs (JIS A)
If it is> 96 °, the bending fatigue property is remarkably deteriorated, and cracks and separation of the extended rubber layer 4 or the compressed rubber layer 5, the adhesive rubber layer 6, and the cord 7 are generated at an early stage.
s (JIS A) = 90-96 °. It is more preferable that the rubber hardness of the extended and compressed rubber layers 4 and 5 is set so that the compressed rubber layer 5 is larger than the extended rubber layer 4 within the above range.

On the other hand, the adhesive rubber layer 6 comprises 100 parts by weight of chloroprene rubber, 30 to 50 parts by weight of a reinforcing filler, and at least one metal oxide vulcanizing agent 1 of zinc oxide, magnesium oxide and lead oxide. To 20 parts by weight, 5 to 30 parts by weight of silica, and 2 to 10 parts by weight of bismaleimide.

The chloroprene rubber may be either of a sulfur-modified type or a non-sulfur-modified type, as in the case of the stretched and compressed rubber layers 4 and 5. It is necessary to incorporate sulfur or a sulfur-releasing component in order to impart adhesiveness to No. 7.
Further, in order to lower the viscosity of the unvulcanized rubber and obtain an adhesive rubber having excellent tackiness, a sulfur-modified type having a creasing property is preferred. In the case of this sulfur-modified type, blending of sulfur or a sulfur releasing component is not an absolute limitation, but it is better to blend it in order to obtain a large adhesive strength. Although various sulfur accelerators include various vulcanization accelerators, it is desirable to add a thiuram accelerator which acts as a retarder for chloroprene rubber.

Silica increases the tear strength of the vulcanized rubber and reduces the RF
It is an indispensable component for adhesion to each L-treated cord 7. If the amount is less than 5 parts by weight, the effect of enhancing the adhesive strength is almost eliminated, while if it is more than 30 parts by weight, poor processability of the unvulcanized rubber and poor dynamic characteristics of the vulcanized rubber will result. It is 5 to 30 parts by weight. Preferably, the amount is 15 to 25 parts by weight.

The amounts of the reinforcing filler (carbon black), the metal oxide vulcanizing agent and the bismaleimide are the same as those of the above-mentioned stretched and compressed rubber layers 4 and 5.

The adhesive rubber layer 6 may contain a conventional lubricant, antioxidant or process oil plasticizer. The amount of these compounds is
Chloroprene compositions are already well known.

The rubber hardness of the adhesive rubber layer 6 is Hs (J
IS A) = 83-89 °. That is, when the rubber hardness is Hs (JIS A)> 89 °,
Separation occurs at an early stage due to a remarkable decrease in adhesiveness. On the other hand, if Hs (JIS A) <83 °, the transmission power transmitted to the extension and compression rubber layers 4 and 5 due to too low elasticity is applied to each cord 7. Hs (JIS A)
= 83 to 89 °.

The Hs (JIS A) in the rubber hardness of each of the rubber layers 4 to 6 is obtained by a spring hardness test (A type) defined in JIS K6301 (vulcanized rubber physical test method). Value.

Therefore, in the above embodiment, the hardness of the stretched and compressed rubber layers 4 and 5 of the low-edge cog type transmission V-belt B is set to Hs (JIS A) = 90 to 96 °, and the hardness of the adhesive rubber layer 6 Is Hs (JIS A) = 83 ~
Since the angle is set to 89 °, the combination of the extension and compression rubber layers 4 and 5 and the adhesive rubber layer 6 is optimal, and cracks and separation of each of the rubber layers 4 to 6 and each of the cords 7 occur early. , While improving the lateral pressure resistance, it is possible to improve the high load transmission capacity.

The stretched and compressed rubber layers 4 and 5 are composed of 100 parts by weight of chloroprene rubber and reinforcing fillers 40 to 60.
Parts by weight, 1 to 20 parts by weight of at least one metal oxide vulcanizing agent of zinc oxide, magnesium oxide and lead oxide,
It is made of rubber containing short fibers in which bismaleimide (2 to 10 parts by weight) and aramid short fibers are blended, and the aramid short fibers are arranged in the belt width direction. Can be effectively improved by increasing only the elastic modulus of the belt, and the belt can be prevented from being damaged early due to an increase in the elastic modulus in the belt longitudinal direction. Therefore, high load transmission capacity and durability can be further improved.

Further, the adhesive rubber layer 6 comprises 100 parts by weight of chloroprene rubber, 30 to 50 parts by weight of a reinforcing filler,
At least one of zinc oxide, magnesium oxide and lead oxide
1 to 20 parts by weight of metal oxide vulcanizing agent and silica 5
Since 30 parts by weight and bismaleimide of 2 to 10 parts by weight are made of rubber, the adhesive rubber layer 6 can be easily formed with Hs (JIS) while maintaining various required properties.
A) = High hardness of 83 to 89 ° can be achieved.
Therefore, an optimal high-load transmission V-belt B can be easily obtained.

In the above embodiment, the rubber hardness of both the expanded and compressed rubber layers 4 and 5 is set to Hs (JIS A) = 90.
However, the hardness of only the compressed rubber layer 5 may be set in the above range, and the hardness of the extended rubber layer 4 may be set to be approximately the same as that of the adhesive rubber layer 6, or Hs (JISA) may be set to be greater than 96 °.
Conversely, the hardness of only the stretched rubber layer 4 is set to the above range,
The hardness of the compressed rubber layer 5 may be approximately equal to that of the adhesive rubber layer 6, or Hs (JISA) may be greater than 96 °. By doing so, it is possible to improve the high load transmission capacity and the durability as compared with the case where the rubber hardness of both the extended and compressed rubber layers 4 and 5 is out of the above range.

[0042]

Next, a specific embodiment will be described. The hardness of the stretched and compressed rubber layer and the hardness of the adhesive rubber layer 6 are Hs (JIS A) = 90 to 96 ° and 83 to 8 respectively.
The transmission V-belt was manufactured by changing the angle in a range of 9 ° (Examples 1 to 4). For comparison, a V-belt (Comparative Examples 1 to 4) in which the hardness of any of the stretched / compressed rubber layer and the adhesive rubber layer is out of the above range, and the hardness of both rubber layers is in the above range. An outer V-belt (Comparative Example 5) was produced (see Table 1 for each hardness). Each V-belt was a B-shaped belt defined by JIS K6323 (general V-belt) and had a cross-sectional shape in which only the belt thickness was reduced to 9 mm.

[Table 1]

Then, the above Examples 1 to 4 and Comparative Examples 1 to
5 was subjected to a high load durability test. That is, as shown in FIG. 2, each of the belts 11 is divided into a driving pulley 12 and a driven pulley 13 having a pulley diameter of 111 mm.
And a reverse bending idler 14 having a diameter of 60 mm at a substantially central portion between the pulleys 12 and 13.
It was pressed against the upper surface with a weighted DW (18 kgf). The driven pulley 13 is loaded with a load of 10 PS to the driven pulley 13.
2 was rotated at a speed of 2900 rpm, and when the trouble occurred, the running was stopped immediately, and the running time (durable time) up to that time and the state of damage were examined. The ambient temperature is 80
Set to ± 5 ° C.

FIG. 3 shows the results of the high load durability test.
In the figure, the vertical axis is a durability index showing a comparison of the durability time of the other V-belts with respect to the durability time of the V-belt of Comparative Example 5 as 100. It has been described. As a result, Examples 1-4
It can be seen that the V-belt has about 3 times the durability as compared to Comparative Example 5, and about 1.5 times as much as Comparative Examples 1-4.

Although the durability of the V belts of Comparative Examples 1 to 4 is higher than that of Comparative Example 5, the V belt of Comparative Example 1 in which the stretched and compressed rubber layers have a slightly lower elasticity is used. The V-belt of Comparative Example 2 in which the transmission capacity is lower than that of Examples 1 to 4 and the durability is deteriorated, and the elasticity is slightly higher than that of Examples 1 to 4, the bending property is lowered and cracks occur. On the other hand, the V-belt of Comparative Example 4 in which the adhesive rubber layer was slightly low in elasticity did not have a transmission capacity enough to transmit the load transmitted to the extension and compression rubber layers to the cord 7, and separation occurred. The V-belt of Comparative Example 3 having slightly high elasticity could not absorb the distortion at the time of bending, and the separation occurred.

Next, a crack durability test was performed on each of the V-belts to examine the effect of cracks due to rubber hardness. That is, as shown in FIG. 4, the same driving and driven pulleys 12 and 13 as those in the high load endurance test are arranged in the vertical direction, and each V-belt 11 is disposed between the pulleys 12 and 13.
In order to easily cause cracks, a reverse bending idler 15 having a small diameter of 45 mm was pressed against the upper surface of the V-belt with a weight DW (18 kgf). Driven pulley 1
The drive pulley 12 is set to 2900 with no load applied to 3.
Rotate at the speed of rpm, and like the high load endurance test,
The durability time and the state of damage were examined. The ambient temperature is 25
Set to ± 5 ° C.

FIG. 5 shows the results of the crack durability test. In addition, all the V belts were damaged by cracks.
As a result, when the stretched and compressed rubber layer or the adhesive rubber layer becomes too high in elasticity, cracks are likely to occur.
V belts Nos. To 4 have almost the same cracking properties as Comparative Example 5 and are found to be good.

[0048]

As described above, according to the first aspect of the present invention, the adhesive rubber layer in which the cord is buried, the extension rubber layer and the compression rubber layer respectively laminated on the upper and lower surfaces of the adhesive rubber layer, A transmission V-belt comprising a canvas layer laminated on at least one of the upper surface of the stretched rubber layer and the lower surface of the compressed rubber layer, and the rubber layers are exposed on both side surfaces and the bottom surface is formed in a cog shape. Hs (JIS A) = 90-9
6 ° and the rubber hardness of the adhesive rubber layer is Hs (JIS
A) = 83 to 89 °, it is possible to improve the high load transmission capability while preventing cracks, separation of each rubber layer and cord from occurring early.

According to the second aspect of the present invention, the stretched and compressed rubber layers are made of 100 parts by weight of chloroprene rubber, 40 to 60 parts by weight of a reinforcing filler, and at least one metal selected from zinc oxide, magnesium oxide and lead oxide. Oxide vulcanizing agent 1-2
0 parts by weight, bismaleimide 2 to 10 parts by weight, and aramid staple fibers, each of which is made of rubber containing short fibers, and the aramid staple fibers are arranged in the belt width direction, so that high load transmission capacity is achieved. Further, the durability life can be further improved.

According to the third aspect of the present invention, the adhesive rubber layer
100 parts by weight of chloroprene rubber and reinforcing filler 30 to
50 parts by weight, 1 to 20 parts by weight of at least one kind of metal oxide vulcanizing agent of zinc oxide, magnesium oxide and lead oxide, 5 to 30 parts by weight of silica, and 2 to 10 parts of bismaleimide
An optimum high-load transmission V-belt can be easily obtained by using the rubber in which the weight parts are compounded.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a transmission V-belt according to an embodiment of the present invention.

FIG. 2 is a schematic view showing a point of a high load durability test.

FIG. 3 is a graph showing the results of a high load durability test.

FIG. 4 is a schematic view showing a point of a crack durability test.

FIG. 5 is a graph showing the results of a crack durability test.

[Explanation of symbols]

 B V belt for transmission 3 Canvas layer 4 Stretch rubber layer 5 Compressed rubber layer 6 Adhesive rubber layer 7 Cord

Claims (3)

[Claims] 1. An adhesive rubber layer in which a cord is embedded, an extended rubber layer and a compressed rubber layer laminated on upper and lower surfaces of the adhesive rubber layer, and at least an upper surface of the extended rubber layer and a lower surface of the compressed rubber layer. In a transmission V-belt composed of a canvas layer laminated on one side, the rubber layers are exposed on both sides and the bottom surface is formed in a cog shape, the rubber hardness of at least one of the stretched and compressed rubber layers is Hs (JIS A) = 90-96 °, and the rubber hardness of the adhesive rubber layer is Hs (JIS A) = 8
A transmission V-belt, which is 3 to 89 °. 2. The transmission V-belt according to claim 1, wherein the stretched and compressed rubber layer comprises 100 parts by weight of chloroprene rubber, 40 to 60 parts by weight of a reinforcing filler, and zinc oxide, magnesium oxide and lead oxide. 1 to 20 parts by weight of at least one kind of metal oxide vulcanizing agent, 2 to 10 parts by weight of bismaleimide, and rubber containing staple fiber in which aramid staple fiber is blended respectively. A transmission V-belt, wherein the transmission V-belt is arranged in a row. 3. The transmission V-belt according to claim 1, wherein the adhesive rubber layer comprises 100 parts by weight of chloroprene rubber, 30 to 50 parts by weight of a reinforcing filler, and zinc oxide, magnesium oxide, and lead oxide. A transmission V-belt comprising a rubber in which 1 to 20 parts by weight of at least one kind of metal oxide vulcanizing agent, 5 to 30 parts by weight of silica, and 2 to 10 parts by weight of bismaleimide are blended. .