JP7336625B1 - V-ribbed belt and its manufacturing method - Google Patents

Abstract

The V-ribbed belt (B) has a plurality of V-ribs (14) provided so as to extend in parallel in the belt length direction. The plurality of V ribs (14) are constructed by covering a plurality of V rib bodies (11a) made of a rubber composition with a covering cloth (15). The surface on the V-rib (14) side includes a non-cloth covering portion (16) that is sandwiched between the edges of the covering cloth (15) and extends across the entire width of the belt.

Description

The present invention relates to a V-ribbed belt and its manufacturing method.

A V-ribbed belt is known in which the surface on the V-rib side is covered with a covering cloth. Japanese Patent Laid-Open No. 2002-100002 discloses forming a tubular shape by joining both side portions of a cloth material to be a covering cloth by sewing. Patent Literature 2 discloses forming a tubular shape by overlapping both edges of a cloth material to be a covering cloth and joining them by adhesion.

JP 2019-132430 A Patent No. 6690047 publication

The present invention provides a V-ribbed belt having a plurality of V-ribs extending parallel to the longitudinal direction of the belt, wherein the plurality of V-ribs are covered with a plurality of V-rib bodies formed of a rubber composition. The V-rib side surface includes a non-cloth-covered portion sandwiched between edges of the covering cloth and extending across the entire width of the belt.

According to the present invention, in the method for manufacturing a V-ribbed belt according to the present invention, a sheet material for forming the non-cloth covered portion is joined as a joining member between the edge portions of the cloth material to be the covering cloth, and the sheet material laminating the edge-to-edge bonded fabric material to an uncrosslinked rubber composition for forming said plurality of V-rib bodies to form an uncrosslinked slab.

1 is a perspective view of a piece of a V-ribbed belt according to an embodiment; FIG. 1 is a plan view of one piece of a V-ribbed belt according to an embodiment on a V-rib side; FIG. It is sectional drawing of a bridge|crosslinking apparatus. It is a cross-sectional enlarged view of one part of a bridge|crosslinking apparatus. FIG. 4 is a first explanatory view showing a method of joining cloth materials that will be a covering cloth. FIG. 10 is a second explanatory view showing a method of joining cloth materials that serve as covering cloth. FIG. 4 is a first explanatory view showing a method of manufacturing a V-ribbed belt according to the embodiment; FIG. 4 is a second explanatory view showing the method of manufacturing the V-ribbed belt according to the embodiment; FIG. 9 is a third explanatory view showing the method of manufacturing the V-ribbed belt according to the embodiment; It is a figure which shows the pulley layout of the belt running test machine for crack resistance test evaluation performed in a room temperature atmosphere.

Hereinafter, embodiments will be described in detail based on the drawings.

1A and B show a V-ribbed belt B according to an embodiment. The V-ribbed belt B according to the embodiment is, for example, a friction transmission belt made of rubber used for an accessory drive belt transmission device provided in an engine room of an automobile.

The V-ribbed belt B according to the embodiment includes a belt body 10 composed of three layers: an inner compression rubber layer 11, an intermediate adhesive rubber layer 12, and an outer extension rubber layer 13. As shown in FIG.

The compression rubber layer 11 is formed in a strip shape having a comb-shaped cross section. The compression rubber layer 11 is provided with a plurality of V-rib main bodies 11a, each of which is composed of a ridge having a substantially inverted triangular cross-section, extending in parallel with the longitudinal direction of the belt while hanging down on the inner peripheral side. there is The adhesive rubber layer 12 and the extension rubber layer 13 are each formed in a band shape with a laterally long rectangular cross section. In addition, it replaces with the extension rubber layer 13, and the back reinforcement cloth may be provided.

The compression rubber layer 11 including a plurality of V-rib main bodies 11a is formed by heating and pressurizing an uncrosslinked rubber composition in which various rubber compounding agents including a cross-linking agent are blended with a rubber component and kneaded to cross-link the rubber component. made of a rubber composition.

Examples of rubber components include ethylene-α-olefin elastomers such as ethylene-propylene-diene terpolymer (EPDM), ethylene-propylene copolymer (EPM), ethylene-butene copolymer (EDM), ethylene-octene copolymer (EOM); synthetic rubbers such as chloroprene rubber (CR); chlorosulfonated polyethylene rubber (CSM); and hydrogenated acrylonitrile rubber (H-NBR). The rubber component is preferably a blend rubber of one or more of these, and more preferably contains an ethylene-α-olefin elastomer from the viewpoint of obtaining excellent low-temperature properties, and may contain EPDM. More preferred. Cross-linking agents include sulfur and organic peroxides. Examples of rubber compounding agents other than cross-linking agents include reinforcing materials such as carbon black, fillers, anti-aging agents, softeners, vulcanization accelerators, vulcanization acceleration aids, and the like.

The adhesive rubber layer 12 and the extension rubber layer 13 are also made of a rubber composition. The compression rubber layer 11, the adhesive rubber layer 12, and the extension rubber layer 13 may be made of the same rubber composition or may be made of different rubber compositions.

The V-ribbed belt B according to the embodiment has a plurality of V-ribs 14 provided so as to extend in parallel with the belt length direction. The number of V-ribs 14 is, for example, 3 to 6 (6 in FIGS. 1A and 1B). These plurality of V-ribs 14 are formed by covering a plurality of V-rib main bodies 11 a of the compression rubber layer 11 with a covering cloth 15 .

The covering cloth 15 is composed of a woven cloth, a knitted cloth, or a nonwoven cloth. Examples of fiber materials forming the covering cloth 15 include cellulosic fibers such as cotton, natural fibers such as wool and silk; aliphatic polyamide fibers, aromatic polyamide fibers, polyester fibers, acrylic fibers, polyvinyl alcohol fibers, and polyurethane threads. Synthetic fibers such as The covering cloth 15 may be formed of a blended yarn or a blended yarn using a plurality of fiber materials.

The cloth material that becomes the covering cloth 15 may be subjected to an adhesion treatment for imparting adhesion to the V-rib main body 11a. As the adhesion treatment, the cloth material to be the coating cloth 15 is immersed in an epoxy solution or isocyanate solution, pulled out, and then heated. There is an adhesion treatment in which the material is immersed in low-viscosity rubber paste, pulled out and then dried, and an adhesion treatment in which the surface of the cloth material on the V-rib main body 11a side is coated with high-viscosity rubber paste and then dried.

In the V-ribbed belt B according to the embodiment, the edges of the covering cloth 15 are not joined, and the surface on the V-rib 14 side, which is the power transmission surface, is sandwiched between the edges of the covering cloth 15 to extend the entire width of the belt. includes a non-fabric covering portion 16 extending straight across the width of the belt.

The non-fabric covering portion 16 is composed of a polymer layer covering the V-rib main body 11a. The polymer layer forming the non-fabric covering portion 16 is made of a polymer material.

The polymeric material forming the non-fabric covering portion 16 may be a crosslinked material. As the polymer material for the cross-linking material, typically, an uncross-linked rubber composition obtained by blending and kneading a rubber component with various rubber compounding agents including a cross-linking agent is heated and pressurized to cross-link the rubber component. A rubber composition may be mentioned. In this case, the rubber composition forming the non-cloth covered portion 16 is the rubber composition forming the compression rubber layer 11 including the plurality of V-rib main bodies 11a and the rubber component from the viewpoint of obtaining integrity with the V-rib main bodies 11a. are preferably the same, and more preferably the same rubber composition as the rubber composition forming the compression rubber layer 11 .

The polymeric material forming the non-fabric covering portion 16 may be an uncrosslinked thermoplastic material. Examples of uncrosslinked thermoplastic polymer materials include uncrosslinked EPDM, uncrosslinked 1,2-polybutadiene, polyethylene, ethylene-vinyl acetate copolymer (EVA), and compositions using these as base polymers. are mentioned. When the non-fabric covered portion 16 is formed only of the EPDM polymer, it does not contain compounding agents, so that it is excellent in workability and can be moderately deteriorated during storage.

The length L of the non-cloth covered portion 16 in the belt length direction may be 0.5 μm or more, 1 mm or more, or 3 mm or more. The dimension L of the non-cloth covered portion 16 in the belt length direction is preferably 60 mm or less, more preferably 50 mm or less, still more preferably 10 mm or less, and even more preferably, from the viewpoint of suppressing noise and wear during belt running. is 5 mm or less. It is preferable that the dimension L in the belt length direction of the non-cloth covered portion 16 is uniform along the belt width direction.

Such a non-cloth covered portion 16 may be provided at only one location in the belt length direction, or may be provided at a plurality of locations in the belt length direction.

By the way, when the both edges of the cloth material to be the covering cloth are joined by sewing or adhesion, in the V-ribbed belt manufactured using it, deformation of the joint portion of the covering cloth that appears on the surface on the V-rib side during belt running. is regulated, stress may concentrate there and cracks may occur. However, according to the V-ribbed belt B according to the above-described embodiment, the edge portions of the covering cloth 15 are not joined as described above, and the non-cloth covering portion 16 is provided between the edge portions. When the belt is running, stress is not concentrated on that portion, so excellent crack resistance can be obtained.

A core wire 17 arranged to form a spiral having a pitch in the belt width direction is embedded in the intermediate portion of the adhesive rubber layer 12 in the belt thickness direction. The core wire 17 is made of, for example, twisted yarn. Examples of the fibrous material forming the cord 17 include polyamide fiber, polyester fiber, aramid fiber, and the like. It is preferable that the twisted yarn that forms the core wire 17 is subjected to an adhesion treatment for imparting adhesion to the adhesive rubber layer 12 . The adhesion treatment includes an adhesion treatment in which the twisted yarn to be the core wire 17 is immersed in an epoxy resin solution or an isocyanate resin solution and heated, an adhesion treatment in which the twisted yarn is immersed in an RFL aqueous solution and then heated, and a twisted yarn that is immersed in rubber paste and then heated. Adhesion processing to dry is mentioned.

Next, a method for manufacturing the V-ribbed belt B according to the embodiment will be described.

2A and B show a cross-linking device 20 used to manufacture a V-ribbed belt B according to an embodiment.

The bridging device 20 comprises a base 21, a cylindrical expansion drum 22 erected thereon, and a cylindrical mold 23 provided outside thereof.

The expansion drum 22 has a hollow columnar drum body 22a and a cylindrical rubber expansion sleeve 22b fitted around the outer circumference of the drum body 22a. A large number of ventilation holes 22c communicating with the inside are formed in the outer peripheral portion of the drum body 22a. Both ends of the expansion sleeve 22b are sealed by fixing rings 24, 25 to the drum body 22a, respectively. The bridging device 20 is provided with pressurizing means (not shown) for introducing and pressurizing high-pressure air into the drum body 22a, and the pressurizing means introduces high-pressure air into the drum body 22a. Then, high pressure air enters between the drum body 22a and the expansion sleeve 22b through the vent hole 22c to expand the expansion sleeve 22b radially outward.

The cylindrical mold 23 is detachable from the base 21 . A cylindrical mold 23 attached to the base 21 is provided concentrically with an interval from the expansion drum 22 . The cylindrical mold 23 has a plurality of V-rib forming grooves 23a each extending in the circumferential direction and connected in the axial direction (groove width direction) on the inner peripheral surface. The bridging device 20 is provided with heating means and cooling means (both not shown) for the cylindrical mold 23, and the temperature of the cylindrical mold 23 can be controlled by these heating means and cooling means.

In manufacturing the V-ribbed belt B according to the embodiment, first, each member is prepared.

Each rubber compounding agent including a cross-linking agent is blended with the rubber component, kneaded with a kneader such as a kneader or a Banbury mixer, and then processed into a sheet having the same cross-sectional shape as the compression rubber layer 11 . Thereby, a rubber sheet of an uncrosslinked rubber composition for forming a compressed rubber layer 11 including a plurality of V-rib main bodies is produced.

Each rubber compounding agent including a cross-linking agent is blended with the rubber component, kneaded with a kneader such as a kneader or a Banbury mixer, and then processed into a thin sheet. Thus, a rubber sheet of the uncrosslinked rubber composition for forming the adhesive rubber layer 12 and the stretchable rubber layer 13 is produced.

After applying a predetermined adhesive treatment to the cloth material that will be the covering cloth 15, the edge portions of the cloth material are joined together as a joining member to form a long and narrow sheet material for forming the non-cloth covering portion 16, thereby forming a cylindrical shape. do. Specifically, as shown in FIG. 3A, one long side portion of the sheet material 16' is superimposed on one end side portion of the cloth material 15' on the belt main body 10 side, and the cloth material 15 ', the other long side of the sheet material 16' is superimposed on the inside of the other end side of ', and as shown in FIG. 3B, the cloth material 15' and the sheet material 16' It is processed into a cylindrical shape by pressing and bonding.

The sheet material 16' is a thermoplastic material sheet when the polymer material forming the non-cloth covered portion 16 is an uncrosslinked thermoplastic material, and when the polymer material forming the non-cloth covered portion 16 is a rubber composition. , an uncrosslinked rubber composition sheet. At this stage, both edges of the cloth material 15' may have a gap therebetween, but they may also be butted against each other without a gap therebetween. In addition, the twisted yarn that becomes the core wire 17 is subjected to a predetermined adhesion treatment.

Next, as shown in FIG. 4A, a cylindrical drum 26 having a smooth surface is covered with a rubber sleeve 27, and a rubber sheet 13' for forming an elastic rubber layer and a rubber sheet 12 for forming an adhesive rubber layer are placed thereon. ' are wound in order and stacked, then a twisted thread 17 ' to be the core wire 17 is spirally wound from above, and then a rubber sheet 12 ' for forming an adhesive rubber layer is wound and stacked from above, Next, a rubber sheet 11' for forming a compression rubber layer is wound and laminated so that the rib side is on the outside, and finally, a sheet material 16' is formed on the rubber sheet 16' to join the edge portions of the coated cloth. A non-crosslinked slab S' is produced by covering and laminating a tubular cloth material 15' to be 15. As shown in FIG.

Next, the rubber sleeve 27 provided with the uncrosslinked slab S' is removed from the cylindrical drum 26, and as shown in FIG. ' ribs are covered with the cloth material 15 ' and are internally fitted so as to be accommodated in the corresponding V-rib forming grooves 23 a , and then the cylindrical mold 23 provided with the uncrosslinked slab S ' is placed on the expansion drum. 22 and attached to the base 21. - 特許庁

Subsequently, the cylindrical mold 23 is heated, and as shown in FIG. 4C, high-pressure air is injected through the ventilation holes 22c between the drum body 22a of the expansion drum 22 and the expansion sleeve 22b to expand the expansion sleeve 22b. Inflate. At this time, the uncrosslinked slab S' is pressed against the cylindrical mold 23, and the rubber sheet 11' for forming the compression rubber layer, the rubber sheet 12' for forming the adhesive rubber layer, and the rubber sheet 12' for forming the stretched rubber layer are formed. The sheet 13' is integrated, the cross-linking of the rubber component progresses, and the cloth material 15', the sheet material 16' joining the edge portions thereof, and the twisted thread 17' are combined with it, and finally a cylindrical belt is formed. A slab S is molded. When the sheet material 16' is an uncrosslinked rubber composition sheet, the rubber component is crosslinked.

After high-pressure air is removed from between the drum main body 22a and the expansion sleeve 22b of the expansion drum 22, the belt slab S molded on the inner peripheral surface of the cylindrical mold 23 is taken out, and the belt slab S is moved to a predetermined V. A V-ribbed belt B is obtained by slicing for each number of ribs 14 and turning it over.

In the above-described embodiment, the non-cloth covered portion 16 extends straight in the belt width direction. However, the present invention is not limited to this. It may be provided so as to have an angle, or may be provided so as to form a curve or a zigzag line.

(V-ribbed belt)
<Example 1>
A V-ribbed belt having three V-ribs in which a compression rubber layer having the same configuration as in the above embodiment is formed of an EPDM rubber composition in which the rubber component is EPDM, and the non-cloth covered portion is a compression material made of a cross-linking material. Example 1 was prepared by forming the same EPDM rubber composition as the rubber layer and setting the dimension L of the non-cloth-covered portion in the belt length direction to 1 μm.

Note that the adhesive rubber layer and the stretched rubber layer were each formed of an EPDM rubber composition having a different formulation from that of the compression rubber layer. The covering fabric was composed of a knitted fabric formed by interlocking cotton and polyurethane yarns subjected to an adhesive treatment. The cord was composed of twisted yarn made of aramid fibers that had been subjected to an adhesive treatment.

<Example 2>
A V-ribbed belt having the same configuration as that of Example 1 except that the dimension L of the non-cloth-covered portion in the belt length direction was set to 5 mm was produced and designated as Example 2.

<Example 3>
A V-ribbed belt having the same configuration as that of Example 1 except that the length L of the non-cloth-covered portion in the belt length direction was set to 50 mm was produced and designated as Example 3.

<Example 4>
A V-ribbed belt having the same configuration as that of Example 1 except that the length L of the non-cloth-covered portion in the belt length direction was set to 60 mm was produced and designated as Example 2.

<Example 5>
A V-ribbed belt having the same configuration as that of Example 1 except that the non-cloth covered portion was formed only of uncrosslinked EPDM polymer, which is a thermoplastic material, was produced and referred to as Example 5.

<Example 6>
A V-ribbed belt having the same structure as that of Example 3 except that the non-fabric covered portion was formed only of uncrosslinked EPDM polymer, which is a thermoplastic material, was produced and referred to as Example 6.

<Example 7>
A V-ribbed belt having the same configuration as that of Example 4 except that the non-cloth covered portion was formed only of uncrosslinked EPDM polymer, which is a thermoplastic material, was produced and referred to as Example 7.

<Example 8>
A V-ribbed belt having the same configuration as that of Example 4 was produced and referred to as Example 8, except that the non-cloth covered portion was formed only of uncrosslinked 1,2-polybutadiene polymer, which is a thermoplastic material.

<Comparative Example 1>
A V-ribbed belt having the same configuration as that of Example 1 except that a cloth material, which was sewn together by butting both ends thereof, was used as the covering cloth, was manufactured and designated as Comparative Example 1.

<Comparative Example 2>
A V-ribbed belt having the same configuration as that of Example 1 was produced, and this was designated as Comparative Example 2, except that a cloth material having both edges overlapped and joined by adhesion was used as the covering cloth.

(Test evaluation method)
FIG. 5 shows the pulley layout of the belt running tester 30 for crack resistance test evaluation performed at room temperature.

In this belt running tester 30, a lower drive pulley 31 and an upper first driven pulley 32, which are rib pulleys having a pulley diameter of 45 mm, are provided at intervals in the vertical direction. An idler pulley 33, which is a pair of flat pulleys with a pulley diameter of 40 mm, is provided on the right side of the middle of the driving pulley 31 and the first driven pulley 32 with a vertical interval therebetween. A second driven pulley 34 which is a rib pulley having a pulley diameter of 45 mm is provided on the right side of the pair of idler pulleys 33 . In this belt running tester 30 , the V-ribbed belt B is wound so that the V-rib side contacts the driving pulley 31 and the first and second driven pulleys 32 and 34 and the back side contacts the pair of idler pulleys 33 .

The V-ribbed belts B of Examples 1 to 8 and Comparative Examples 1 to 2 were wound around the belt running tester 30 . A dead weight (DW) of 588 N was loaded upward on the first driven pulley 32 to provide belt tension. In this state, a test was conducted in which the driving pulley 31 was rotated at a rotation speed of 5100 rpm in a room temperature atmosphere (23±5° C.) to run the belt. Then, the running of the belt was periodically stopped, and the surface of the V-ribbed belt B on the V-rib side was visually observed. When a crack reaching the bottom of the V-rib was observed, the running of the belt was stopped, and the running time of the belt until then was defined as the crack resistance life at room temperature.

In addition, A was evaluated when the sound was small when the belt was running, and B was evaluated when the sound was large.

(Test results)

Test results are shown in Tables 1 and 2. According to these Tables 1 and 2, Examples 1 to 8 in which the surface on the V-rib side includes a non-cloth covered portion are comparative example 1 in which a cloth material with both edges joined by adhesion is used as a covered cloth, and both edges It can be seen that the crack resistance is superior to that of Comparative Example 2, in which the covering cloth is made of a cloth material in which parts are sewn together.

INDUSTRIAL APPLICABILITY The present invention is useful in the technical field of V-ribbed belts and manufacturing methods thereof.

B V-ribbed belt S Belt slab S' Uncrosslinked slab 10 Belt body 11 Compressed rubber layers 11', 12', 13' Rubber sheet 12 Adhesive rubber layer 13 Stretched rubber layer 14 V-rib 15 Covering cloth 15' Cloth material 16 Non-cloth covering Part 16' Sheet material 17 Core wire 17' Twisted yarn 20 Cross-linking device 21 Base 22 Expansion drum 22a Drum main body 22b Expansion sleeve 22c Vent hole 23 Cylindrical mold 23a V-rib forming grooves 24, 25 Fixing ring 26 Cylindrical drum 27 Rubber sleeve 30 Belt running tester 31 Drive pulley 32 First driven pulley 33 Idler pulley 34 Second driven pulley

Claims (8)

A V-ribbed belt having a plurality of V-ribs extending parallel to the belt length direction,
The plurality of V-ribs are configured by covering a plurality of V-rib bodies formed of a rubber composition with a covering cloth,
A V-ribbed belt, wherein the surface on the V-ribbed side includes a non-cloth-covered portion sandwiched between edges of the covering cloth and extending across the entire width of the belt. In the V-ribbed belt according to claim 1,
A V-ribbed belt, wherein the non-cloth covered portion is made of a rubber composition. In the V-ribbed belt according to claim 2,
A V-ribbed belt, wherein the rubber composition forming the non-cloth covered portion has the same rubber component as the rubber composition forming the plurality of V-ribbed main bodies. In the V-ribbed belt according to claim 3,
A V-ribbed belt, wherein the rubber composition forming the non-cloth covered portion is the same as the rubber composition forming the plurality of V-rib main bodies. In the V-ribbed belt according to claim 1,
A V-ribbed belt, wherein the non-fabric covered portion is made of a thermoplastic material. In the V-ribbed belt according to claim 1,
A V-ribbed belt, wherein the dimension of the non-cloth-covered portion in the belt length direction is 0.5 μm or more and 60 mm or less. In the V-ribbed belt according to claim 1,
A V-ribbed belt in which the non-cloth-covered portion extends straight in the width direction of the belt. In the method for manufacturing a V-ribbed belt according to claim 1,
A sheet material for forming the non-cloth covering portion is joined as a joining member between the edge portions of the cloth material to be the covering cloth,
A method for producing a V-ribbed belt, comprising the step of fabricating an uncrosslinked slab by laminating a fabric material having edges joined together with the sheet material on an uncrosslinked rubber composition for forming the plurality of V-rib main bodies.