JP2006118661A - Transmission belt - Google Patents

Abstract

An object of the present invention is to effectively prevent a reduction in transmission capability and abnormal noise caused by slippage of a transmission belt during water injection.
Short fibers 10, 10,... Made of gelable polyvinyl alcohol fibers subjected to RFL treatment are embedded in the rib rubber of the rib portion 8 of the compressed rubber layer 6 of the V-ribbed belt B which is a transmission belt. At the time of water injection of the belt B, the short fibers 10 on the surface of the rib portion 8 are gelated by water absorption, so that the water layer is not formed at the interface between the belt B and the pulley, and the interface is kept free of water. The resulting reduction in the transmission capability of the belt B and the generation of abnormal noise due to slip are suppressed.
[Selection] Figure 1

Description

  The present invention relates to a transmission belt such as a V-ribbed belt or a V-belt, and more particularly to a technique for ensuring transmission capability at the time of water injection and preventing occurrence of abnormal noise.

  Conventionally, for example, as a V-ribbed belt used in an auxiliary drive system of an engine mounted on an automobile, a short fiber cut to a length of several millimeters is filled in a rib rubber of a rib portion in contact with a pulley in the compressed rubber layer. Embedded ones are known. By filling the short fibers, the friction coefficient of the rib rubber against the pulley is lowered to prevent the generation of abnormal noise while the belt is running and to suppress the wear of the rib rubber.

  However, there is no problem when the belt is dried, but when water is poured into the belt, a slip occurs due to the water layer generated at the interface between the belt and the pulley, and this slip reduces the transmission capability of the belt. There was a problem that sound was generated.

For this reason, for example, as shown in Patent Document 1, in a transmission belt including not only a V-ribbed belt but also other types, 1 to 100 parts by weight of water-soluble short fibers are added to the compression rubber layer of rubber of the compression rubber layer. Filled with 20 parts by mass, the water-soluble short fibers on the surface of the compressed rubber layer are dissolved and removed by the presence of water so that a recess is formed in the trace. It has been proposed to destroy the layer and suppress the generation of noise due to belt slip.
JP 2003-314624 A

  However, in the thing of the said patent document 1, since water is accommodated in the recessed part of the surface of a compression rubber layer, there is a limit in water absorption amount, and when a large amount of water enters at the time of water injection, it becomes impossible to absorb water, and a belt, a pulley, It was insufficient to effectively prevent the reduction of transmission ability and the generation of abnormal noise due to slip caused by the water layer generated at the interface.

  The present invention has been made in view of such a point, and its object is to specify the short fibers filled in the compression rubber layer of the transmission belt, thereby reducing the transmission capability of the belt due to slippage during water injection and abnormal noise. It is to be able to effectively prevent the occurrence of occurrence.

  In order to achieve the above object, in the present invention, the short fiber is made of a gelable polyvinyl alcohol fiber obtained by RFL treatment.

  Specifically, in the first aspect of the invention, in the transmission belt in which the compression rubber layer is disposed on the belt bottom surface side of the core wire, the compression rubber layer is made of a short gel composed of RFL-treated gelable polyvinyl alcohol fiber. The fiber is embedded so as to be exposed on the surface of the compressed rubber layer.

  According to the above configuration, since the short fibers embedded in the compressed rubber layer are gelable polyvinyl alcohol fibers subjected to RFL treatment, when the water is poured into the belt, the short fibers on the surface of the compressed rubber layer It absorbs water and gels. And even if a large amount of water enters, the gelled fiber breaks through the water film. By these actions, compared to the case where water is accommodated by forming a recess by dissolving and removing water-soluble short fibers on the surface of the compressed rubber layer, the effect of not forming a water layer at the interface between the belt and the pulley is extremely large. Is kept free of water. As a result, it is possible to secure a large transmission capability of the belt at the time of water injection and to reduce the generation of abnormal noise due to slip.

  In the invention of claim 2, the short fiber is included in an amount of 1 to 30 parts by mass with respect to 100 parts by mass of the rubber of the compressed rubber layer. By this, the composition ratio of the short fiber which can show the said effect effectively is obtained easily.

  In the invention of claim 3, the transmission belt is a V-ribbed belt in which a plurality of rib portions extending in parallel to each other in the belt length direction are formed in the compressed rubber layer. According to a fourth aspect of the present invention, the power transmission belt is a V-belt in which a compression rubber layer is formed in a substantially V-shaped cross section. Furthermore, in the invention of claim 5, the transmission belt has a back cloth layer made of a stretchable cloth formed on the back of the belt, and a groove extending in the belt length direction is formed in the compressed rubber layer. Thus, a transmission coupling V-belt in which a plurality of V-belt portions having a V-shaped cross section are arranged in parallel in the belt width direction. In the invention of claim 6, the transmission belt is a flat belt. According to these inventions, a transmission belt desirable for achieving the transmission capability of the belt during water injection and reducing the occurrence of abnormal noise can be obtained.

  As described above, according to the first aspect of the present invention, the short fiber embedded in the compression rubber layer of the transmission belt is made into a gelable polyvinyl alcohol fiber subjected to RFL treatment, so that the surface of the compression rubber layer is injected when the belt is poured. By making the short fibers exposed from the water-absorbing gel, the belt-pulley interface can be kept free from water, ensuring effective transmission of the belt and reducing noise from slipping. .

  Further, according to the invention of claim 2, the composition ratio of the short fibers having the above effects can be easily obtained by setting the composition ratio of the short fibers to 1 to 30 parts by mass with respect to 100 parts by mass of the rubber of the compressed rubber layer. Is obtained.

  Furthermore, in the invention of claim 3, the transmission belt is a V-ribbed belt. In the invention of claim 4, the transmission belt is a V-belt. Further, in the invention of claim 5, the transmission belt is a transmission coupling V belt in which a plurality of V belt portions extending in the belt length direction are arranged in parallel in the belt width direction on the belt bottom surface. In the invention of claim 6, the transmission belt is a flat belt. Therefore, according to these inventions, a transmission belt suitable for achieving the transmission capability of the belt during water injection and reducing the occurrence of abnormal noise can be obtained.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is in no way intended to limit the invention, its application, or its application.

  FIG. 1 shows a V-ribbed belt B as a transmission belt according to an embodiment of the present invention, and this belt B is used, for example, in an accessory drive system for an automobile engine. The V-ribbed belt B includes an adhesive rubber layer 2 embedded in a state where the core wire 1 is spirally arranged at a predetermined pitch in the belt width direction, and an extended rubber layer disposed on the belt back side of the adhesive rubber layer 2 3, and a back rubber 4 disposed on the belt back surface side of the stretched rubber layer 3 and a compression rubber layer 6 disposed on the belt bottom surface side of the adhesive rubber layer 2 are laminated and integrated. A canvas may be provided in place of the back rubber 4. Further, the stretch rubber layer 3 may be omitted.

  In the compressed rubber layer 6, a plurality of (three in the illustrated example) rib portions 8, 8,... Extending in parallel with each other in the belt length direction are arranged at a constant pitch in the belt width direction. It is formed in a state.

  For the adhesive rubber layer 2, for example, EPDM, carbon black, silica, paraffin oil, cotton, stearic acid, zinc oxide, anti-aging agent, calcium oxide, tackifier, sulfur, vulcanization accelerator, and the like are used. For the back rubber 4, for example, EPDM, carbon black, paraffin oil, stearic acid, zinc oxide, anti-aging agent, sulfur, vulcanization accelerator, nylon fiber and the like are used. For the stretch rubber layer 3, for example, EPDM, carbon black, silica, paraffin oil, stearic acid, zinc oxide, anti-aging agent, sulfur, vulcanization accelerator, and the like are used. Further, for example, EPDM, carbon black, paraffinic oil, stearic acid, zinc oxide, anti-aging agent, sulfur, nylon fiber, etc. are used for the compressed rubber layer 6.

  The core 1 is made of ethylene-2,6-naphthalate fiber (PEN fiber), polyethylene terephthalate fiber (PET fiber), polyvinyl alcohol fiber (PVA fiber), aramid fiber, or the like.

  In the compressed rubber layer 6, short fibers 10, 10,... Are blended in the rib rubber constituting each rib portion 8, and a part of the short fibers 10, 10,... Is exposed from the surface of each rib portion 8. Thus, for example, the rib fibers 10 are oriented and embedded in the belt width direction (the orientation direction of the short fibers 10 may be random and embedded so as to be exposed on the surface of the compressed rubber layer 6. Just fine). The short fiber 10 is a gelable polyvinyl alcohol fiber that has been RFL-treated (a treatment in which a fiber is immersed in a resorcin-formalin-latex solution in which an initial condensate of resorcin and formalin is mixed with latex to form an adhesive layer on the surface). 1 to 30 parts by mass, that is, 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the rubber of the compressed rubber layer 6.

  That is, when the composition of the short fibers 10, 10,... With respect to 100 parts by mass of the rubber of the compressed rubber layer 6 is less than 1 part by mass, the water absorption effect of the RFL-treated polyvinyl alcohol fiber is not sufficiently exerted, while 30 parts by mass. If it exceeds the part, the rubber becomes hard and the cracking of the belt is accelerated, so the amount is 1 to 30 parts by mass.

  Therefore, in this embodiment, the short fibers 10, 10,... Are embedded in the rib rubber of each rib portion 8 constituting a part of the compressed rubber layer 6 of the V-ribbed belt B, and the short fibers 10 are subjected to RFL treatment. Since it is a gelable polyvinyl alcohol fiber, for example, when the V-ribbed belt B used in an auxiliary machine drive system for an automobile engine is injected with water due to rain or car washing of the automobile, each rib portion 8 The surface short fibers 10, 10,... Absorb water and gel. And even if a large amount of water enters, the gelled fiber breaks through the water film, and thereby, the interface between the belt B and the V-ribbed pulley (not shown) around which the belt B is wound. No water layer is formed on the surface, and the interface is kept free of water. As a result, it is possible to secure a large transmission capability of the belt B at the time of water injection and to reduce the occurrence of abnormal noise due to slip.

(Other embodiments)
In the above embodiment, the present invention is applied to the V-ribbed belt B, but the present invention can also be applied to other known transmission belts. For example, a V-belt in which the compressed rubber layer is formed in a substantially V-shaped cross section or a back cloth layer made of an elastic cloth bonded to the back of the belt is formed, while the compressed rubber layer is formed in the belt length direction. A transmission coupling V-belt in which a plurality of V-belt portions having a V-shaped cross section are formed in parallel with each other in the belt width direction, and further a flat belt may be formed. What is necessary is just to embed the short fiber which consists of the gelable polyvinyl alcohol fiber which carried out RFL process in the rubber layer.

(Examples 1-5)
Next, specific examples will be described. A V-ribbed belt having the same configuration as that of the above embodiment was produced, and the composition ratio of short fibers made of RFL-treated polyvinyl alcohol fiber (trade name “Claron K-II”) filled in the compressed rubber layer was changed. 1-5.

(Comparative Examples 1-3)
Comparative examples 1 to 3 were made by using short fibers made of nylon fibers in place of the polyvinyl alcohol fibers of the above examples, and changing the composition ratio filled in the compressed rubber layer.

  In each of the above Examples 1 to 5 and Comparative Examples 1 to 3, the rubber composition of the adhesive rubber layer, the back rubber and the stretch rubber layer is shown in Table 1, and the rubber composition of the compression rubber layer is shown in Table 2, respectively. . The core wire is obtained by pre-treating polyethylene terephthalate fiber with isocyanate and immersing it in an RFL solution, followed by drying by heating to form a uniform adhesive layer on the surface.

  The belt transmission performance and sound generation performance were evaluated for each of the examples and comparative examples thus obtained. In the belt transmission performance evaluation, the load in a 2% slip state during the dry running and the water running was obtained.

  On the other hand, in the evaluation of the sound production performance, the sound production limit tension in the water injection state was tested. In this test, as shown in FIG. 2, the V-ribbed belts 16 of the example and the comparative example are stretched between the driving and driven pulleys 14 and 15 made of a V-ribbed pulley having a diameter of 120 mm separated in the horizontal direction. In a state where the belt tension is applied by applying a load of 588 N in the direction in which the distance between the shaft and the drive pulley 14 is increased, the drive pulley 14 is rotated at 3500 rpm and a flow rate of 120 ml / min is applied to the drive pulley 14 side. The sounding limit when the load of the driven pulley 15 was changed was measured while pouring water. The ambient temperature was 23 ° C. These results are shown in Table 3.

  Looking at the results in Table 3, the loads during drying in Examples 1 to 5 are lower than those in Comparative Examples 1 to 3, but are substantially the same. Moreover, while the load at the time of water injection of the comparative example is greatly reduced compared with that at the time of dryness, the load at the time of water injection of Examples 1 to 5 is not as large as that of Comparative Examples 1 to 3 from the time of dryness. . Moreover, the load at the time of water injection of these Examples 1-5 is larger than Comparative Examples 1-3. Therefore, in Examples 1-5, it turns out that the high transmission capability can be ensured without the slip of a belt at the time of water injection.

  Moreover, since the sound production limit tension | tensile_strength of Examples 1-5 is substantially larger than Comparative Examples 1-3, it turns out that generation | occurrence | production of the noise at the time of water injection does not arise easily. That is, it is clear from these results that the present invention is practically effective.

  The present invention is extremely useful and has high industrial applicability because it is highly effective in ensuring the transmission capability during water injection of the transmission belt and suppressing the occurrence of abnormal noise.

It is a perspective view which shows the principal part of the V-ribbed belt which concerns on embodiment of this invention. It is a figure which shows schematically the test | inspection apparatus of sound generation limit tension | tensile_strength.

Explanation of symbols

B V-ribbed belt (power transmission belt)
1 Core 6 Compressed Rubber Layer 8 Rib 10 Short Fiber

Claims (6)

In the transmission belt in which the compression rubber layer is disposed on the belt bottom surface side of the core wire,
A power transmission belt, wherein short fibers made of gelable polyvinyl alcohol fibers subjected to RFL treatment are embedded in the compressed rubber layer so as to be exposed on the surface of the compressed rubber layer. The transmission belt according to claim 1,
1 to 30 mass parts of short fibers are contained with respect to 100 mass parts of rubber | gum of a compression rubber layer, The transmission belt characterized by the above-mentioned.   3. The transmission belt according to claim 1, wherein the compression rubber layer is a V-ribbed belt in which a plurality of rib portions extending in parallel to each other in the belt length direction are formed.   The transmission belt according to claim 1 or 2, wherein the compression rubber layer is a V-belt having a substantially V-shaped cross section. While the back fabric layer made of elastic fabric is formed on the back of the belt,
The compression rubber layer has a groove portion extending in the belt length direction, and a plurality of V belt portions having a V-shaped cross section are juxtaposed in the belt width direction by the groove portion. The transmission belt according to claim 1 or 2.   The transmission belt according to claim 1, wherein the transmission belt is a flat belt.

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