JP2002039278A - Power transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power transmission belt with superior wear resistance causing no separations between rubber foundation cloths even when traveling for a long time and blocking sound generation during a back face drive. SOLUTION: In a V-ribbed belt 1, a compressed rubber layer 4 provided with rib parts is arranged adjacent to an adhesive rubber layer 2 embedded with cores 3 along a belt longitudinal direction and a fiber base material 6 is laminated on a belt back face. In the fiber base material 6, a foundation cloth 7 woven from warps and wefts composed of a filament yarn or a spun yarn of cotton or nylon fiber and a foundation cloth 8 woven from warps composed of a filament yarn or a spun yarn of aramid fiber and wefts composed of a filament yarn or a monofilament yarn of aramid fiber are combined via an adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission belt, and more particularly to a power transmission belt such as a V-belt or a V-ribbed belt that transmits power by friction.

[0002]

2. Description of the Related Art Conventionally, fabrics made of natural fibers have been widely used for canvas used for power transmission belts such as V-belts and V-ribbed belts. However, natural fibers are liable to wear due to contact with pulleys and There was a problem such as abnormal pronunciation. In consideration of the above problem, it has been proposed to use a woven fabric having a surface friction coefficient as low as possible when designing a belt with emphasis on wear resistance and sound generation resistance. The surface friction coefficient is affected by various factors such as the chemical composition of the fiber, the form of the constituent yarn, and the woven composition. Specifically, (1) a woven fabric using a rigid fiber represented by an aramid fiber (2) A woven fabric in which the diameter of the constituent yarn is large and the yarn density is low (3) A woven fabric using a filament yarn as the weft, a woven fabric combining the above structures, and the like are known in the world.

[0003]

However, a belt using the above woven fabric for the back canvas has excellent abrasion resistance and sound generation resistance, but for example, (1) a rigid fiber represented by aramid fiber is used. In the case of the woven fabric used, since the aramid has low molecular structure and low reactivity with rubber, there is a possibility that the woven fabric will peel off from the rubber when the belt is run for a long time. In the case of using (2) a fabric using low-density and large-diameter fibers or (3) a fabric using a monofilament yarn as the weft as the back canvas, the anchor effect is low due to less irregularities on the fiber surface. There is a problem with adhesion to rubber.

In recent years, with the advancement of functions and performance in the automotive industry, power transmission belts have also been required to have high added functions. As described above, since the required performance and function of the front and back surfaces of the canvas are different, it is currently impossible to satisfy the demand with the conventional canvas having the same configuration on both the front and back surfaces.

The present applicant has proposed the present invention in view of the above background, and has a configuration in which at least a belt bonding surface and a pulley contact surface are different at least on the back surface of a belt that transmits power by friction. And a power transmission belt in which a composite canvas in which two types of base fabrics are integrated is coated and laminated. Specifically, a base fabric having a specific configuration having a high adhesive force with rubber is in contact with the belt surface, and a base fabric having a specific configuration excellent in wear resistance and sound generation resistance is in contact with the pulley surface. The belt is covered with a composite canvas united by an adhesive.

[0006]

That is, according to the first aspect of the present invention, a compression layer, an extension layer, and an adhesive layer are provided between both layers, and a core wire is embedded in the adhesive layer along the longitudinal direction of the belt. In a power transmission belt in which at least the back surface of the belt is laminated and covered with a fiber base material, the fiber base material is a composite canvas in which two types of base fabrics are integrated so as to have different configurations at a rubber bonding surface and a pulley contact surface. It is a feature. 2 with different configurations
By using a composite canvas in which a kind of base fabric is integrated as a reinforcing fabric, it is possible to provide a power transmission belt having new characteristics that have not been achieved in the past.

According to a second aspect of the present invention, in the power transmission belt according to the first aspect, the fibrous base material has at least one of the constitutions (A) and (B); (B) a composite canvas in which a base fabric having at least one configuration is integrated by interposing an adhesive, wherein (A) a component yarn is made of spun yarn, and (B) a component material is cotton. (C) The warp or weft is made of monofilament yarn. (D) The constituent material of the warp and weft is made of rigid fiber, and (A) the base fabric adheres to rubber. The composite canvas is laminated and coated on a belt. By using a base cloth having a good adhesion to rubber (A) and (B) as shown in (A) and (B) on the rubber bonding surface of the composite canvas, the rubber and the base cloth do not peel off even when used for a long time. By using a base fabric having a low surface friction coefficient such as (C) and (D) for the pulley contact surface of the composite canvas, a power transmission belt excellent in wear resistance and sound generation resistance can be provided. Further, the composite of the base cloth is very strong because of the interposition of an adhesive, and does not peel off during running.

According to a third aspect of the present invention, in the power transmission belt according to the second aspect, the rigid fibers are aramid fibers. By selecting an aramid fiber having excellent heat resistance among the rigid fibers, it is possible to provide a belt having excellent physical property retention and dimensional stability at high temperatures.

According to a fourth aspect of the present invention, a compression layer, an extension layer, and an adhesive layer are provided between the two layers, and a core wire is embedded in the adhesive layer along the longitudinal direction of the belt. In the power transmission belt laminated and covered with the above, the fiber base material is: (c) a woven fabric woven from a filament yarn made of cotton or nylon or a warp and a weft composed of spun yarn; and (d) a filament yarn of a rigid fiber or A composite canvas in which a woven fabric obtained by weaving a warp composed of a spun yarn and a filament yarn of a rigid fiber or a weft composed of a monofilament yarn through an adhesive is provided.
A power transmission belt, wherein the composite canvas is laminated and coated on the belt so that the woven fabric adheres to rubber. (C) The use of cotton or nylon fibers, which have good adhesion to rubber, for the warp and weft yarns in the base fabric prevents the rubber base fabric from peeling off even after long running. A belt with rigidity fibers used for warp and weft, and with a weft configuration of filament or monofilament, which maintains strength while lowering the surface friction coefficient, and has excellent wear and sound resistance. Can be provided.

According to a fifth aspect of the present invention, in the power transmission belt according to the fourth aspect, the rigid fibers are aramid fibers. By selecting an aramid fiber having excellent heat resistance among the rigid fibers, it is possible to provide a belt having excellent physical property retention and dimensional stability at high temperatures.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a V-ribbed belt as an example of the power transmission belt according to the present invention. V-ribbed belt 1
Has a compression rubber layer 4 in which a core wire 3 is embedded in the adhesive rubber layer 2 along the longitudinal direction of the belt, and a plurality of ribs are provided below the adhesive rubber layer 2 in the longitudinal direction of the belt. Further, a fiber base material 6 is laminated on the adhesive rubber layer 2 as an extension layer, and the fiber base material 6 has a structure in which a base cloth 7 and a base cloth 8 are stacked and combined. More specifically, the base fabric 7 has one surface adhered to the adhesive rubber layer 2 and the other surface adhered to the base fabric 8, and the base fabric 8 has one surface adhered to the base fabric 7, and the other surface adhered to a pulley (see FIG. (Not shown).

The base fabric 7 is a base fabric selected from a woven fabric, a knitted fabric, and a non-woven fabric. In addition, it is preferable to use a high-strength woven fabric for the base fabric 8 that contacts the pulley. Each of the base fabrics is combined with a base fabric by a publicly known method, for example, by heat fusion, bonding, and mechanically sewing with a thread such as a needle punch method or a stitch bond method. Is performed. Above all, bonding is a technique that is preferably used because of its strong adhesion. The bonding process is a bonding method with an adhesive interposed therebetween.Specifically, after a melt-softened resin composition is pressure-bonded to one base cloth, the resin composition is once cooled and then heated again to soften the resin composition. At this point, a fusion bonding method in which the other base cloth is adhered, an adhesive method in which an adhesive is applied to the surface to be bonded of the base cloth and bonded to each other are exemplified. The method of applying the adhesive includes a doctor method, a roll method, an inversion method, a spray method, and a powder dispersion method. The adhesive used for the bonding process is not limited,
Known and publicly available ones can be used, for example, acrylic ester emulsions, urethane resins, ethylene-
An adhesive such as a vinyl acetate copolymer is generally used, and among them, the use of a urethane resin is preferable because of its excellent adhesion.

After the bonding of the base cloth as described above, a pre-drying is performed by applying a pressure with a constant load. The predrying conditions vary depending on the thickness and type of the base fabric,
It is preferable to carry out at 0 ° C. for about 5 to 10 minutes. After the completion of the preliminary drying, curing is performed. In the case of curing, it is preferable to perform heat treatment while pressing as described above.

As the fiber material constituting the base fabric, known and publicly usable ones can be used. For example, natural fibers such as cotton and hemp, inorganic chemical fibers such as metal fibers and glass fibers, and polyamides, polyesters, polyethylenes and the like can be used. Examples include organic chemical fibers such as polyurethane, polystyrene, polyfluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester, and aramid.

However, it is an essential condition that the base cloth 7 on the rubber bonding surface and the base cloth 8 on the pulley contact surface have different configurations. By compounding two or more types of base fabrics having different configurations, it is possible to obtain a composite fiber base material having various characteristics, and it is possible to obtain a belt utilizing the characteristics. The configuration described here indicates, for example, the chemical composition of the fiber material, the form of the constituent yarn, the woven composition, the type of the base fabric, and the like. Specifically, it is desirable that the base cloth 7 has a configuration that has good adhesion to the rubber layer.
It is preferable to have a structure excellent in abrasion resistance and sound generation resistance because it comes into contact with the pulley when driving the rear surface.

More specifically, the base fabric 7 that adheres to rubber is preferably made of, for example, a material such as cotton or nylon, which is highly reactive in terms of molecular structure and has excellent adhesiveness to rubber. . The form of the fiber is desirably a structure having a high anchor effect. For example, a spun yarn is preferably used rather than a filament yarn. Rigid fibers are generally considered to have low adhesion to rubber, but when spun yarn is used, adhesion is good. As the type of base cloth,
Although not limited to woven fabric, knitted fabric, nonwoven fabric, etc., for example, using a nonwoven fabric results in a belt structure having excellent flexibility, and using a woven fabric results in a belt structure having excellent strength.

The base fabric 8 which comes into contact with the pulley preferably has a structure having a low coefficient of surface friction, and it is preferable to use a woven fabric such as plain weave, twill weave, satin weave or the like.
As the material, it is preferable to use rigid fibers, and specific examples include wholly aromatic polyester fibers, heterocyclic rigid polymer fibers such as polyparaphenylenebenzobisoxazole, and meta-aramids and para-aramids. Whole aromatic polyester fibers can be mentioned, and among them, aramid fibers having excellent heat resistance are preferably used. Further, as a form of the fiber, a filament yarn is preferably used because it has higher strength than a spun yarn. Incidentally, a monofilament yarn may be used as the constituent yarn to increase the unevenness due to the intersection of the warp and the weft to reduce the surface friction coefficient. In addition, lowering the weaving density and using fibers having a large diameter are effective means for lowering the surface friction coefficient. It is desirable that the monofilament yarn is used for the weft in consideration of the strength.

The fibrous base material 6 obtained as a composite in this manner is dipped in a resorcinol-formalin-latex liquid (RFL liquid) according to a known technique, and then subjected to friction for rubbing unvulcanized rubber onto the fibrous base material 6. After immersion in the RFL solution, immersion treatment is performed in a soaking solution in which rubber is dissolved in a solvent. The RFL solution is a mixture of an initial condensate of resorcinol and formalin and a rubber latex, and a molar ratio of resorcinol to formalin of 1: 0.5 to 3 is preferable from the viewpoint of increasing the adhesive strength. The initial condensate of resorcinol and formalin is used as a rubber component of latex.
After mixing with latex so that the resin content is 10 to 100 parts by weight per 0 parts by weight, the total solid content concentration is 5 to 100 parts by weight.
Adjusted to 40% concentration. The RFL liquid may be appropriately mixed with a carbon black liquid to blacken the treated material, or a known surfactant may be added in an amount of 0.1 to 5.0% by weight. Examples of the latex include styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer, EPDM and the like. Latex is mentioned.

The main rubber of the compressed rubber layer 4 includes ethylene-α-olefin copolymers such as natural rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer rubber, chloroprene rubber and ethylene-propylene rubber. Polymer rubber, nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR) to which unsaturated carboxylic acid metal salt is added, alkylated chlorosulfonated polyethylene (ACSM), chlorosulfonated polyethylene rubber (CSM), etc. As a main component, and a reinforcing agent such as carbon black, a filler, a softening agent, an antioxidant, a vulcanization aid, a vulcanizing agent such as sulfur or an organic peroxide, and the like are added and mixed.

On the other hand, the same rubber as the compressed rubber layer 4 can be used for the adhesive rubber layer 2. It is preferable not to mix short fibers as a blend, but if necessary, carbon black, an enhancer such as silica, a filler such as calcium carbonate and talc, a plasticizer, a stabilizer, a processing aid, and a coloring agent. Those used for ordinary rubber compounding are used.

Examples of the short fibers include aramid fibers, polyamide fibers, polyester fibers, and cotton. By adding the short fibers, the lateral pressure resistance of the compressed rubber layer 4 is improved, and the short fibers protrude from the surface of the compressed rubber layer 4 which is in contact with the pulley, thereby lowering the friction coefficient of the compressed rubber layer 4. In this way, noise during belt running is reduced. Of these staple fibers, aramid staple fibers having rigidity, strength and abrasion resistance are most effective. Also, when the direction of the short fibers in the rubber layer is 90 ° that is perpendicular to the longitudinal direction of the belt, most of the short fibers are oriented in the range of 70 ° to 110 °. It is desirable.

In order for the above-mentioned aramid short fibers to sufficiently exhibit the above-mentioned effects, the fiber length of the aramid fibers should be 1-20.
In mm, the amount is 1 to 30 parts by weight based on 100 parts by weight of the elastomer component. The aramid fiber is an aramid having an aromatic ring in its molecular structure, such as, for example, Conex, Nomex, Kevlar, Technora, Twaron and the like. When the amount of the aramid short fiber is less than 1 part by weight, there is a disadvantage that the rubber of the compressed rubber layer 4 easily sticks and wears, and when it exceeds 30 parts by weight, the short fiber is contained in the rubber. It will not be evenly dispersed. However, the addition of this aramid short fiber is not essential, and may be the one to which short fibers made of other materials are added.

As the core wire 3, polyester fiber, aramid fiber and glass fiber are used.
Adhesive-treated cords having a total denier of 4,000 to 8,000, in which polyester fiber filaments mainly composed of 2,6-naphthalate are twisted, can lower the belt slip rate and extend the life of the belt. Preferred. The twist number of this cord is 10-23 / 10
cm, and the number of twists is 17 to 38/10 cm. If the total denier is less than 4,000, the modulus and strength of the cord become too low, and if it exceeds 8,000, the belt becomes thick and the bending fatigue becomes poor.

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 completion of the polymerization of ethylene-2,6-naphthalate, a copolymer polyester is synthesized.

The core wire 3 is subjected to an adhesive treatment for the purpose of improving the adhesiveness with rubber. As such an adhesive treatment, the fiber is made of resorcin-formalin-latex (RF
L) Generally, after immersion in the liquid, the adhesive layer is uniformly formed on the surface by heating and drying. However, without being limited to this, there is a method of performing a pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.

The cord having been subjected to the adhesive 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 it is less than 1.0 mm, the cord runs over the adjacent cord and cannot be wound, while if it exceeds 1.3 mm, the modulus of the belt gradually decreases.

Next, an example of a method for manufacturing the V-ribbed belt 1 will be described below. First, after winding a fiber base material and an adhesive rubber around the peripheral surface of a cylindrical forming drum, a cord made of a rope was spun spirally thereon, and a compressed rubber layer was sequentially wound thereon to obtain a laminate. Thereafter, it is vulcanized to obtain a vulcanized sleeve. Next, the vulcanization sleeve is hung between the drive roll and the driven roll, and is run under a predetermined tension, and the rotated grinding wheel is moved so as to abut the running vulcanization sleeve to compress the vulcanization sleeve. A plurality of 3 to 100 groove portions are ground on the surface of the rubber layer at a time. The vulcanized sleeve obtained in this manner is removed from the drive roll and the driven roll, and the vulcanized sleeve is hung on another drive roll and the driven roll to travel, cut to a predetermined width by a cutter, and cut into individual pieces. Finish with a V-ribbed belt.

The V-ribbed belt is an embodiment of the present invention and is not limited to this. For example, a V-belt 9 is shown in FIG. 2 as another example of the power transmission belt according to the present invention. The V-belt 9 has a cord 3 embedded in the adhesive rubber layer 2 along the longitudinal direction of the belt, and has an extended rubber layer 5 and a compressed rubber layer 4 adjacent to the upper and lower portions of the adhesive rubber layer 2. . The stretch rubber layer 5 has a fiber base material 6 laminated on the surface thereof, and the fiber base material 6 has a structure in which a base cloth 7 and a base cloth 8 are stacked and combined. More specifically, the base cloth 7 is bonded to the stretched rubber layer 5 and the base cloth 8, and the base cloth 8 has one surface bonded to the base cloth 7 and the other surface connected to a pulley (not shown). It has become. In addition, the same rubber as the compression rubber 4 can be used for the extension rubber layer 5. The compressed rubber layer 4 may be provided with cogs at predetermined intervals along the longitudinal direction. The flat belt is also a belt that transmits power by friction and is included in the technical scope of the present invention.

[0029]

The present invention will be described in more detail with reference to the following examples. Examples 1 to 3, Comparative Examples 1 and 2 In the V-ribbed belt manufactured in this example, a core wire made of a polyester fiber rope was embedded in the adhesive rubber layer,
On the upper surface thereof, a composite fiber base material is laminated in one ply, while a compressed rubber layer provided with five ribs in the longitudinal direction of the belt is provided below the adhesive rubber layer. Here, a compressed rubber layer and an adhesive rubber layer were prepared from the rubber compositions shown in Table 1, respectively, kneaded with a Banbury mixer, and then rolled with calender rolls. The compressed rubber layer contains short fibers and is oriented in the belt width direction. Further, the fiber base material of the example is a cylindrical body obtained by bonding and processing a plain woven cloth shown in Table 2 with a urethane-based resin to form a composite, and an RFL solution (styrene-butadiene-vinylpyridine terpolymer 100) Parts by weight, resorcinol 14.6 parts by weight, formalin 9.2 parts by weight, caustic soda 1.5 parts by weight, water 262.5 parts by weight).

[0030]

[Table 1]

The method for producing the V-ribbed belt is an ordinary method. First, one ply of the composite fiber base material is inserted into a drum as a canvas, and then an adhesive rubber layer is wound thereon, and the core wire is spun. After the compressed rubber layer is further disposed, a crosslinking jacket is inserted on the compressed rubber layer. Next, the mold was placed in a vulcanizing can and crosslinked, and then the tubular crosslinked sleeve was removed from the mold. The compression rubber layer of the taken-out sleeve is formed into a rib by a grinder, cut into individual belts from the formed body, and has a length of 975 mm according to RMA standard, a rib pitch of 3.56 mm, a rib height of 2.0 mm, and a belt thickness of 4. 3mm, rib angle 40 °
No. 5 ribbed belt was obtained.

The evaluation of the adhesion between the rubber and the fibrous base material of the V-ribbed belt thus obtained was carried out according to JIS K 625.
According to No. 6, a flat peeling test was performed. The surface friction coefficient on the back of the belt was measured by a pulley rotation method. Pulley diameter 6
A V-ribbed belt was installed so that the back of the belt was in contact with a 0 mm pulley, a load of 2.87 kg was applied, and a contact angle of 90 V was applied.
°, at a rotation speed of 43 rpm, the friction coefficient was measured. Table 2 also shows these results.

[0033]

[Table 2]

From the above results, it can be seen that the example is a V-ribbed belt having both the same strong adhesive strength as the comparative example 1 and the low surface friction coefficient as the comparative example 2.
Further, Example 2 using a monofilament yarn of polyethylene terephthalate (PET) as a flexible fiber on the pulley contact surface side has a surface friction coefficient similar to Examples 1 and 3 using an aramid fiber as a rigid fiber. It turns out that it has. Further, even when the material is the same as in Examples 1 and 3, the diameter of the constituent fibers is larger and the yarn density is lower in Example 3
Has a lower surface friction coefficient.

[0035]

As described above, according to the invention described in the present application, a fiber base material in which at least two types of base fabrics are combined so that the configuration of the rubber bonding surface and the pulley contact surface are different is provided on the back surface of the belt. In the laminated power transmission belt, the use of a base fabric with a specific structure with a low surface friction coefficient on the pulley contact surface of the fiber base material improves wear resistance during back driving and prevents noise generation Also, by using a base fabric having a specific configuration excellent in adhesion to rubber on the other surface of the fiber base material, a belt with excellent durability in which the base fabric and rubber are not peeled off even during long running is provided. We were able to.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view of a V-ribbed belt according to the present invention.

FIG. 2 is a sectional perspective view of a V-belt according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 V ribbed belt 2 Adhesive rubber layer 3 Core wire 4 Compressed rubber layer 5 Extension rubber layer 6 Fiber base material 7 Base cloth 8 Base cloth 9 V belt

Claims (5)

[Claims] 1. A power source having a compression layer, an extension layer, and an adhesive layer between both layers, a core wire embedded in the adhesive layer along the longitudinal direction of the belt, and at least the back surface of the belt laminated and covered with a fiber base material. In the power transmission belt, the fiber base material has a different configuration 2
A power transmission belt characterized by being a composite canvas in which a kind of base fabric is integrated. 2. The fibrous base material is composed of an adhesive (A) having at least one of (A) and (B) and an adhesive (B) having at least one of (C) and (D) as an adhesive. (A) the constituent yarn is made of spun yarn, (B) the constituent material is made of cotton fiber or nylon fiber, and (C) the warp or weft is a monofilament. 2. The belt according to claim 1, wherein the constituent material of (D) the warp and the weft is made of a rigid fiber, and (a) the composite canvas is laminated and coated on a belt so that the base fabric is bonded to rubber. Power transmission belt. 3. The power transmission belt according to claim 2, wherein the rigid fibers are aramid fibers. 4. A power source having a compression layer, an extension layer, and an adhesive layer between both layers, a core wire embedded in the adhesive layer along the longitudinal direction of the belt, and at least the back surface of the belt laminated and covered with a fiber base material. In the power transmission belt, the fiber base material is composed of (c) a woven fabric obtained by weaving a warp and a weft composed of a filament yarn or a spun yarn made of cotton or nylon, and (d) a filament yarn or a spun yarn of a rigid fiber. A composite woven fabric obtained by integrating a warp yarn and a woven fabric made of a filament yarn of a rigid fiber or a weft made of a monofilament yarn through an adhesive, wherein the woven fabric is bonded to rubber. A power transmission belt, wherein the composite canvas is laminated and coated on the belt. 5. The power transmission belt according to claim 4, wherein the rigid fibers are aramid fibers.