JP2010175013A - Power transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power transmission V-belt, capable of preventing heat generation or friction during traveling of the belt by reducing the lateral friction coefficient of a cog part, in addition to improvement in lateral pressure resistance of the belt, and further minimizing the increase in weight. <P>SOLUTION: The power transmission belt 1 includes a compression rubber layer 6 and an extension rubber layer 5 disposed adjacently to an adhesive rubber layer 2 having a core wire 3 embedded therein, at least the compression rubber layer 6 including a cog part in which a cog mount part 8 and a cog valley part 7 are alternately disposed. A reinforcing member 9 is embedded and disposed in the rubber constituting the cog part C to improve the lateral pressure resistance of the belt. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  Conventionally, in a drive system of a scooter, buggy, snowmobile (snowmobile) or general industrial machinery field, a power transmission belt is suspended between a drive pulley and a driven pulley, and the effective diameter of the pulley is changed to change the speed. A belt-type transmission is used. The power transmission belt used here has a cog portion in which a cog crest portion and a cog trough portion are alternately arranged on both the compression rubber layer and the stretch rubber layer or the rubber layer of the compression rubber layer. It has a configuration embedded in an adhesive rubber layer, and is known as a low edge cogged belt such as a low edge double cogged belt or a low edge single cogged belt.

  These belts are mainly made of rubber and have good flexibility due to the provision of cogs on the stretch rubber layer and compression rubber layer, but on the other hand, while the belt is running as shown in FIG. In order to receive a large lateral pressure from the pulley P, the belt B as a whole may be bent and deformed in the lateral direction to form a dish-like shape in cross-section and fall downward in the pulley groove.

  When dishing occurs, the belt slips, causing a reduction in transmission force, and a member such as a core wire constituting the belt is peeled off, thereby causing an early breakage. Therefore, fiber materials such as short fibers, canvases, and saddles have been embedded in the cogs of the belt in a lateral direction so as not to deform the belt.

  However, in recent years, there is a great demand for high torque belts, and the demand for such belts tends to increase. However, rubbers embedded with reinforcing fibers such as short fibers, canvas, or sudder as described above are used for motorcycles and large-sized belts. It cannot be said that it has sufficient durability as a belt for high torque used in agricultural machines.

  For reinforcing such a cogged V-belt, there are the following prior patents. For example, Patent Document 1 discloses a porous sintered material such as a sintered metal or a porous ceramic sintered body coated with a plating or resin layer. A belt is disclosed in which a bonded structure is inserted in a belt width direction at a cog portion of the belt.

  Further, in Patent Document 2, a plurality of layers of elastic spring plates are laminated in a state in which a rubber layer is interposed between the spring plates, and the laminate is placed in the cog portion so as to reinforce the belt width direction. There is disclosed a power transmission V-belt that can withstand side pressure from a pulley by being inserted and buried.

  Further, Patent Document 3 discloses a belt in which a transverse reinforcing member is disposed across a cog of a belt that is also used for CVT or the like. The lateral reinforcing member is made of a plastic such as polyether ether ketone or a non-metallic substance, and suppresses wear on the side surfaces of the cogs and reduces heat generation.

Japanese Utility Model Publication No. 61-32188 Japanese Utility Model Publication No. 62-6349 Japanese translation of PCT publication No. 2004-507672

  In the belt disclosed in Patent Document 1, by embedding a sintered body of metal or ceramics in the cog in the belt width direction, the lateral pressure resistance of the belt is increased and deformation is suppressed, and the belt transmission efficiency is lowered or shortened. However, in metal sintered bodies and ceramics, heat generation occurs due to friction with the pulleys, resulting in seizure, so it must be impregnated with a lubricant. Don't be.

  In the belt described in Patent Document 2, a plurality of layers of elastic spring plates are embedded in the cog portion with a rubber layer interposed therebetween, and also for the purpose of increasing the side pressure resistance in the cog portion of the belt. The belt has elasticity in the belt width direction to improve impact resistance during travel, but the friction coefficient on the side of the belt cannot be adjusted, and rubber layers are interposed between the spring plates. , Cost and effort.

  Patent Document 3 is characterized in that a lateral reinforcing member made of a non-metallic material, a thermoplastic material, a thermosetting material, or the like is provided in the cog portion of the CVT belt. By providing the lateral reinforcing member, The side pressure resistance can be reinforced and the side of the belt can be controlled to control noise, wear and heat generation, but it has a volume that occupies a significant part of the cog, avoiding an increase in weight. It is considered that there is a problem in durability because the rubber layer around the reinforcing member is thin and the thickness of the rubber layer is reduced.

  Therefore, in the present invention, the lateral pressure resistance of the belt can be improved, the friction coefficient on the side surface of the cog portion is reduced to prevent heat generation and wear during belt running, and the increase in weight is suppressed to a small one. The purpose is to provide a power transmission V-belt that can be used.

  In order to achieve the above object, in claim 1, a compression rubber layer and an extension rubber layer are disposed adjacent to the adhesive rubber layer in which the core wire is embedded, and at least the compression rubber layer alternates between the cog crest portion and the cog trough portion. In the power transmission belt having a cog portion arranged, a reinforcing member that penetrates the cog portion in the belt width direction and whose side surface is flush with the side surface of the belt is disposed, and both ends of the reinforcing member are made of resin. It is made of material.

  According to a second aspect of the present invention, the reinforcing member is a power transmission belt according to the first aspect, wherein the reinforcing member includes a central column portion and pulley contact portions at both ends larger in diameter than the column portion.

  The power transmission belt according to any one of claims 1 and 2, wherein the support portion is made of metal and the pulley contact portion is made of resin.

  In Claim 4, the said reinforcement member can be divided | segmented in the center, and it inserts into the through-hole provided in the cog part of the belt from right and left both sides, and connects in the center. The power transmission belt described in the above.

  In the power transmission belt according to claim 1 of the present invention, a through hole is provided in the cog portion and reinforcing members made of a resin material are arranged at both ends, and the side pressure resistance of the cog portion can be reinforced. The problem of the belt falling into the pulley groove and deforming, such as the dishing phenomenon in the pulley during traveling, can be prevented, and a decrease in belt transmission efficiency can be suppressed.

  According to a second aspect of the present invention, the reinforcing member is composed of a central column portion and pulley contact portions at both ends having a diameter larger than that of the column portion. The contact portion can improve the slip of the side surface of the cog portion of the belt, and heat generation and wear during belt running can be reduced. Further, since only the pulley contact portion has a large diameter, the entire reinforcing member can be reduced in weight, so that an increase in centrifugal force due to an increase in the weight of the belt and a failure in the belt due to the increase in the centrifugal force can be prolonged. .

  According to the third aspect, since the column portion is made of metal, the strength is high and the pulley can sufficiently withstand the side pressure, and since the pulley contact portion is made of resin, the friction coefficient is small and the sliding property is improved. It is also excellent, and wear and heat generation can be reduced.

  In Claim 4, what can be divided | segmented as a reinforcing member can be inserted and connected later to the through-hole provided in the cog part, and the assembly of a reinforcing member can also be made simpler. .

  Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 is a partial front view of a power transmission belt according to the present invention, FIG. 2 is a sectional view of the power transmission belt shown in FIG. 1, FIG. 3 is a sectional view of the power transmission belt in the manufacturing process, and FIG. It is a partial front view of the other power transmission belt according to the invention.

  The power transmission belt 1 of the present invention has a stretched rubber layer 5 in which a core wire 3 made of a fiber cord is embedded in an adhesive rubber layer 2 and the rubber is exposed on the back surface of the adhesive rubber layer 2. In the lower part, there is a compressed rubber layer 6 in which a cover canvas 4 is laminated. The compressed rubber layer 6 is provided with cog portions C in which cog valley portions 7 and cog mountain portions 8 are alternately arranged along the belt longitudinal direction at a constant pitch. A cover canvas may also be laminated on the upper surface of the stretch rubber layer 5.

  The power transmission belt 1 according to the present invention is mainly used for a transmission belt. When the output of the engine increases, it is necessary to transmit a large torque, and the side pressure from the pulley becomes large. In order to transmit power smoothly, it is necessary to withstand a large lateral pressure and maintain the shape of the belt. If the belt is not greatly deformed, the vibration of the running belt can be reduced, and the generation of noise and wear can be reduced.

  By making the rubber constituting the belt highly elastic, the side pressure resistance can be increased and the shape of the belt can be maintained, but the flexibility of the belt will be impaired, and it will be difficult to wind around a small-diameter pulley. As a result, there arises a problem that the power transmission efficiency is lowered or the belt is cracked by repeated bending.

  Therefore, in the belt of the present invention, the reinforcing member 9 penetrating in the belt width direction is disposed through the cog C. The reinforcing member 9 includes a central support column 9a and pulley contact portions 9b at both ends having a diameter larger than that of the support column 9a. The strut part is a part that receives the side pressure received from the pulley when the belt enters the pulley, and the material is preferably made of a metal such as stainless steel or aluminum alloy, but a resin material such as a thermosetting resin or a thermoplastic resin. It doesn't matter. Resin reinforced with fibers to increase strength can also be used.

  The pulley contact portion 9b is a portion that is flush with the side surface of the belt and is in contact with the pulley, and preferably has a relatively low friction coefficient so that it does not easily wear even if it is rubbed against the pulley. Examples of the material include resin, and examples of the thermosetting resin include phenol resin, epoxy resin, polyarylate resin, and the like, and thermoplastic resins include polyamide 4/6, polyamide 9T, and polyamide. Examples thereof include polyether ether ketone, which has a low friction coefficient and is not easily worn.

  In the support column 9a and the pulley contact portion 9b, the diameter d of the support column 9a is smaller, and the diameter D of the pulley contact portion 9b is larger. Even if the diameter d of the support column 9a is small, a high-strength material such as a metal is used in order to provide sufficient side pressure resistance, thereby suppressing an increase in the weight of the belt. If the belt weight becomes too large, the centrifugal force at the time of running increases, and the burden on each material constituting the belt, such as the cord and rubber, increases, resulting in a shortened life.

  Further, the diameter D of the pulley abutting portion 9b is large and can occupy a considerable part of the side surface of the belt in the cog C. Therefore, heat generation due to contact with the pulley and wear on the side surface of the belt can be widely reduced. Thus, the life of the belt can be made longer.

  As a method of manufacturing a belt having a structure as in the present invention, a rod having substantially the same diameter as that of the support column 9a was embedded in the cog at the time of forming a belt shape from unvulcanized rubber, and vulcanized and cured. By removing the rod later, a through hole can be formed in the cog portion as shown in FIG. Then, a split-type reinforcing member is inserted into the through-hole from both sides and connected in the penetrating premises, whereby a belt in which the reinforcing member is disposed in the cog portion can be manufactured.

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

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

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

  The power transmission belt 1 shown in FIG. 4 is an example of a double cogged V-belt having cogs C on the upper side of the stretched rubber layer 5 where the cogs 9 and cogs 8 are alternately arranged. In such a belt, it is possible to provide a reinforcing member not only on the lower cog C of the belt but also on the upper cog C.

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

  The cover canvas 4 is not necessarily provided. If the arrangement of the cover canvas is omitted, the flexibility of the belt is positive, and even when used with a small pulley diameter, the belt bends well, causing cracks from the belt surface or slipping between the pulleys. Can be improved. However, in general, a belt not provided with a reinforcing canvas is easily deformed, and the belt is bent or twisted not only in the longitudinal direction but also in the lateral direction, so that the shape retainability cannot be said to be high. Therefore, there is a problem in that belt vibration is generated due to deformation during belt running. In the present invention, since the reinforcing layer made of fiber reinforced resin is embedded in the compressed rubber, it has the effect of improving the lateral pressure resistance of the belt and reinforcing against deformation such as torsion. The belt shape retention can be improved while reducing the decrease as much as possible.

  Hereinafter, the effects of the present invention will be confirmed by more specific experimental examples.

Example 1
As Example 1, both a stretch rubber layer and a compression rubber layer have a cog portion, and a belt in which a through hole is provided in the cog portion and a reinforcing member is inserted is used for the compression rubber layer. As the reinforcing member, a member in which a pulley contact portion made of polyamide 4/6 resin is attached to both ends of a stainless steel post portion is used. In addition, the diameter of the support | pillar part was 2.8 mm, and the diameter in the belt side surface position of a pulley contact part was 5.0 mm.

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

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

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

  As a cog pad, a laminate of one reinforcing cloth, a sheet for a compressed rubber layer having a predetermined thickness (first layer), one sheet, a sheet for a compressed rubber layer having a predetermined thickness (second layer), and a tooth portion The groove portions were placed on a flat cogged mold, and pressed at 75 ° C. to form a cog pad in which the cog portions were molded. At that time, a rod for forming a through hole in the cog portion was embedded in advance. Both ends of the cog pad were cut vertically from the top of the cog crest.

  After preparing these materials, wrap a cog pad around the inner base mold mounted on the mold and joint it, and then joint a sheet of compressed rubber layer sheet and adhesive rubber sheet of a predetermined thickness in advance at another position Then, a core and a flat stretched rubber layer were sequentially wound to prepare a molded body. Subsequently, after the mold was placed at a predetermined position on the support base, a vulcanized rubber cylindrical mother die having concave portions provided at predetermined intervals along the circumferential direction was inserted. Then, the jacket was put on and the mold was placed in a vulcanizing can and vulcanized to obtain a belt sleeve. This sleeve was cut into a V shape by a cutter to finish a transmission belt (size: upper width 29.8 mm, thickness 16.4 mm, outer peripheral length 866 mm).

  A durability running test was performed using the obtained belt. The results (belt life and its cause of failure) are shown in Table 1. In the endurance running test, the belt is suspended in a biaxial horizontal running test machine arranged in a thermostatic bath composed of a driving pulley having a diameter of 100 mm and a driven pulley having a diameter of 100 mm, and a fixed frame is placed in the thermostatic bath on the loose side of the belt. And the distance from the back of the belt is 15 mm. The input torque was 3.0 kgf, a load of 60 kgf was applied to the driven pulley, the rotational speed was varied at 7,000 rpm ± 500 rpm, and the ambient temperature was 90 ° C.

(Example 2)
In Example 2, a belt that is exactly the same as that of the Example except that a reinforcing member having a constant diameter of 2.8 mm including the diameter of the support column and the diameter of the pulley contact part was used, and the durability running was performed. A test was conducted. The results are shown in Table 1.

(Example 3)
In Example 3, a belt that is exactly the same as that of the Example except that a reinforcing member having a constant diameter of 5.0 mm including the diameter of the support column and the diameter of the pulley abutting part was used, and durability running was performed. A test was conducted. The results are shown in Table 1.

(Comparative Example 1)
In Comparative Example 1, a belt exactly the same as that of the Example was prepared except that the reinforcing member was not embedded in the cog portion, and the durability running test was performed under the same conditions. The results are shown in Table 1.

  As a result, Example 1 ran for a considerable length of time, but no abnormality occurred and the test was interrupted after 200 hours. It can be seen that wear on the side surface of the belt is suppressed by the reinforcing member embedded in the cog.

  In contrast to this, although the reinforcing member is arranged, in Example 2 in which the reinforcing member has a small diameter and a constant diameter including the pulley abutting portion from the support portion, it was possible to secure a certain traveling time. The wear on the side of the belt cannot be suppressed and the amount of wear increases, reaching the end of its service life. Moreover, in Example 3, the diameter of the reinforcing member is too large and occupies most of the cog, the rubber layer covering the reinforcing member becomes too thin, and the reinforcing member falls off in the middle, resulting in a lifetime. Yes. In Comparative Example 1, in Comparative Example 1 in which the reinforcing member was not embedded in the cog portion, the service life was reached in a very short time due to wear on the belt side surface.

  From these facts, it can be seen that by embedding a reinforcing member in the cog portion, it is possible to improve the wear resistance of the side surface of the belt, and the diameter of the reinforcing member is made small near the center embedded in the cog portion, and the belt By making the diameter large on the side surface, it is possible to reduce the wear on the side surface of the belt without lowering the retention brain of the reinforcing member by the rubber forming the cog portion, and it is possible to provide a belt having a longer life. all right.

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

It is a partial front view of the power transmission belt according to the present invention. It is sectional drawing of the power transmission belt shown in FIG. It is sectional drawing of the belt for power transmission before mounting | wearing with a reinforcement member. It is a partial front view of the other power transmission belt according to the present invention. It is sectional drawing which shows a mode that the belt is dishing.

DESCRIPTION OF SYMBOLS 1 Power transmission belt 2 Adhesive rubber layer 3 Core wire 4 Reinforcement canvas 5 Stretch rubber layer 6 Compression rubber layer 7 Cog valley part 8 Cog mountain part 9 Reinforcement member C Cog part

Claims (4)

  For power transmission, a compression rubber layer and a stretch rubber layer are arranged adjacent to the adhesive rubber layer in which the core wire is embedded, and at least the compression rubber layer has a cog portion in which a cog mountain portion and a cog valley portion are alternately arranged. In the belt, there is disposed a reinforcing member that penetrates the cog portion in the belt width direction and whose side surface is flush with the belt side surface, and both ends of the reinforcing member are made of a resin material. Belt.   2. The power transmission belt according to claim 1, wherein the reinforcing member includes a central column portion and pulley contact portions at both ends larger in diameter than the column portion.   The power transmission belt according to claim 1, wherein the support column portion is made of metal, and the pulley contact portion is made of resin.   The power according to any one of claims 1 to 3, wherein the reinforcing member can be divided at the center, and is inserted into a through hole provided in a cog portion of the belt from both left and right sides and connected at the center. Transmission belt.

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