WO2020175215A1

WO2020175215A1 - V-ribbed belt and method for producing same

Info

Publication number: WO2020175215A1
Application number: PCT/JP2020/006079
Authority: WO
Inventors: 友哉真銅
Original assignee: バンドー化学株式会社
Priority date: 2019-02-25
Filing date: 2020-02-17
Publication date: 2020-09-03
Also published as: JP6755430B1; JPWO2020175215A1

Abstract

A V-ribbed belt (B) has a plurality of V-ribs (15). Each of the plurality of V-ribs (15) includes a V-rib main body (11a) formed by a rubber composition, and a covering cloth (14) that covers both sides thereof. The V-rib main body (11a) is exposed at the edge of each of the plurality of V-ribs (15) along the belt longitudinal direction.

Description

\¥0 2020/175 215 1 卩 (: 17 2020 /006079 Clarification

Title of invention: V-ribbed belt and its manufacturing method

Technical field

[0001] The present invention relates to a V-ribbed belt and a method for manufacturing the same.

Background technology

[0002] As a means for suppressing the generation of abnormal noise when exposed to water, Patent Document 1 discloses a V-ribbed belt in which a coating cloth is provided on the surface of the V-rib. Further, Patent Document 2 discloses a V-ribbed belt in which both side surfaces of the V-rib are formed of porous rubber and the tips are formed of solid rubber.

Prior art documents

Patent literature

[0003] Patent Document 1: Japanese Unexamined Patent Publication No. 20 15-4 2 9 03

Patent Document 2: Patent No. 6 0 0 7 3 5 3 Publication

Summary of the invention

[0004] The present invention is a V-ribbed belt having a plurality of V-ribs, wherein each of the plurality of V-ribs includes a V-rib body formed of a rubber composition and both side surfaces of the V-rib body. The V-rib body is exposed at the tip end along the belt length direction.

[0005] The present invention is a method for producing a V-ribbed belt having a plurality of V-ribs, comprising a V-ribbed body formed of a rubber composition and a coated cloth that covers the entire surface of the V-ribbed body. A V-rib front structure including the V-rib front structure is formed, and by removing the covering cloth at the tip of the V-rib front structure along the belt length direction, both side surfaces of the V-rib body are covered with the covering cloth, In addition, the V-rib is formed so that the V-rib main body is exposed along the belt length direction at the tip portion.

Brief description of the drawings

[0006] [Fig. 18] A perspective view of a belt piece of a V-ribbed belt according to an embodiment.

[FIG.] A sectional view of one V-rib of the V-ribbed belt according to the embodiment. 〇 2020/175 215 2 (:171? 2020/006079

[Figure 2] Pulley layout of the auxiliary drive belt transmission.

[Fig. 38] A cross-sectional view of the bridging device.

FIG. 38 is an enlarged cross-sectional view of a part of the bridging device.

FIG. 48 is a first explanatory diagram of the method for manufacturing a V-ribbed belt according to the embodiment.

FIG. 48 is a second explanatory view of the method for manufacturing the V-ribbed belt according to the embodiment.

FIG. 6 is a third explanatory view of the method for manufacturing the V-ribbed belt according to the embodiment.

FIG. 40 is a fourth explanatory view of the method for manufacturing the V-ribbed belt according to the embodiment.

[Fig. 5] Fig. 5 is a pulley layout diagram of a belt running tester for a water injection transmission capacity test. FIG. 68 is a front view of the belt power loss measuring device.

FIG. 68 is a plan view of the belt power loss measuring device.

[FIG. 7] A graph showing the maximum values of the generated torques of Examples and Comparative Examples.

FIG. 8 is a graph showing loss power of Examples and Comparative Examples.

MODE FOR CARRYING OUT THE INVENTION

[0007] Hereinafter, embodiments will be described in detail with reference to the drawings.

[0008] FIG. 1 and FIG. 9 show a V-ribbed belt according to an embodiment. The V-ribbed belt according to the embodiment is, for example, a rubber friction transmission belt used for an auxiliary drive belt transmission device provided in an engine room of an automobile. The ▽ ribbed belt according to the embodiment has, for example, a belt circumference of 700

Above 3 0 0 0 111 111 Below, the belt width is

And the belt thickness is 4.0 111 111 or more and 5.0 111 111 or less.

[0009] The V-ribbed belt according to the embodiment includes an inner peripheral compression rubber layer 11 formed of a rubber composition, an intermediate adhesive rubber layer 12 and an outer peripheral extension rubber layer 1 3 respectively. It has a belt main body 10 composed of three layers.

[0010] The compression rubber layer 11 is formed with a plurality of V rib main bodies 11 13 hanging down on the inner peripheral side. Each of the plurality of V-rib bodies 1 13 is composed of a protrusion having a substantially inverted triangular cross section that extends in the belt length direction, and is arranged in parallel in the belt width direction. The thickness of the compressed rubber layer 11 is, for example, 2.2011 or more and 3.20101 or less. 〇 2020/175 215 3 (:171? 2020/006079

[001 1] The adhesive rubber layer 12 is formed in a strip shape having a horizontally long rectangular cross section. Adhesive rubber layer 1

The thickness of 2 is, for example, 1.

It is the following. The stretched rubber layer 13 is also formed in the shape of a strip with a horizontally long rectangular cross section, and its thickness is, for example, 0.4 or more and 0.8

It is the following. The surface of the stretched rubber layer 13 is preferably provided with a woven fabric pattern from the viewpoint of suppressing the generation of sound when driving the back surface. A back reinforcing cloth may be provided instead of the stretched rubber layer 13.

[0012] The rubber composition forming the compressed rubber layer 11, the adhesive rubber layer 12 and the stretched rubber layer 13 is prepared by mixing and kneading various rubber compounding agents including a cross-linking agent in a rubber component. A rubber component is crosslinked with a crosslinking agent by heating and pressurizing the crosslinked rubber composition. The compressed rubber layer 11, the adhesive rubber layer 12 and the stretched rubber layer 13 may be formed of the same rubber composition or different rubber compositions.

[0013] Examples of the rubber component of these rubber compositions include, for example, ethylene-propylene-gen terpolymer (Mai 0 1\/1), ethylene-propylene copolymer (Mani 1\/1), and ethylene- Butene copolymers (_ 0 1\/〇, ethylene-octene copolymers (_ 0 1\/1), etc. Ethylene- _ olefin elastomers; chloroprene rubber (〇[¾); chlorosulfonated polyethylene rubber (〇 31) \/〇 ;Hydrogenated acrylonitrile rubber (1 ^to 1-Min [¾), etc. It is preferable to use one or more of these as the rubber component. It is more preferable to use a lastomer,

Is more preferably used. Crosslinking agents include sulfur and organic peroxides. Examples of the rubber compounding agent other than the cross-linking agent include a reinforcing material such as carbon black, a filler, an antioxidant, a softening agent, a vulcanization accelerator, and a vulcanization acceleration aid.

[0014] Each of the plurality of V-rib bodies 1 13 of the compressed rubber layer 11 has a covering cloth on both sides.

It is covered with 14 to form V-ribs 15. V-ribs 1 5, the V-ribs body 1 1 ₃ formed in the compression rubber layer 1 1 of the rubber composition, and a target drapes 1 4 covering the both sides thereof, and belt length direction on the tip portion The elongated V-rib body 1 1 3 of the rubber composition is exposed as a surface along. In addition, a pair of adjacent 〇 2020/175 215 4 卩 (：171? 2020 /006079

In the V ribs 15, the covering cloths 14 on the opposite side surfaces are bent at the bottoms of the ribs, and the covering cloths 14 are formed in an inverted II shape in cross section. Each V-rib 15 has, for example, a rib height of 2

Below, the width between the rib base ends is 1.

0 or more 3.

It is the following. The number of ribs is, for example, 3 or more and 6 or less (6 in Fig. 18). The thickness of the covering cloth 14 is, for example, 〇.

[0015] Generally, a V-ribbed belt having a V-ribbed surface provided with a covering cloth has a problem that a loss of transmission dynamic power is large. However, according to the ∇ ribbed belt according to the embodiment, it is possible to suppress the generation of abnormal noise when the vehicle is exposed to water, and it is possible to suppress the loss of transmitted power. As described above, the fact that both sides of the V rib 15 that contacts the pulley is covered with the covering cloth 14 suppresses the generation of abnormal noise when exposed to water. It is considered that this is because the V rib main body 113 of the rubber composition is exposed at the front end of No. 5 and the belt rigidity is lowered, which reduces the loss of transmitted power. The exposed width of the V-rib body 1 13 is preferably 35% or more and 70% or less with respect to the width between the rib base ends of the V-rib 15 from the viewpoint of minimizing the loss of transmitted power.

[0016] The coated cloth 14 is composed of a woven cloth, a knitted cloth, or a non-woven cloth. The covering cloth 14 is preferably made of a knitted cloth among them from the viewpoint of being highly stretchable and uniformly covering the side surface of the V-rib body 1 13 as well as suppressing the loss of transmitted power. ..

[0017] The knitted cloth covering cloth 14 may be either a horizontal knitted cloth or a warp knitted cloth. Examples of the horizontal knitted fabric include a plain knitted fabric, a rubber knitted fabric, and a pearl knitted fabric having a basic structure, and a tuck knitted fabric, a floating knitted fabric, a pile knitted fabric, a lace knitted fabric, and the like having a variable structure. The warp knitted fabric includes, for example, a basic design of single-denb-knitted fabric, a single band-dike knitted fabric, a variable-structured double-denby knitted fabric, and a double-banddike knitted fabric. The cover cloth 14 is preferably a weft knitted cloth among these from the viewpoint of suppressing the generation of abnormal noise when exposed to water. 〇 2020/175 215 5 (:171? 2020/006079

A flat knitted fabric is more preferable.

[0018] The plain knitted cloth 14 is provided so that the front stitches are exposed and the back stitches are on the V-rib body 1 13 side from the viewpoint of suppressing the generation of abnormal noise when exposed to water. This is preferable. From the same viewpoint, it is preferable that the plain knitted cloth 14 is provided so that the wale direction is the belt length direction and the course direction is the belt width direction. From the same viewpoint, the number of stitches of the cover cloth 14 of the flat knitted cloth is preferably 55 or more and 80 or less courses per 2.540, and 2.

It is preferably 40 to 70 wales.

[0019] yarns forming a coated fabric 1 4, the side surface of the V-ribs body 1 1 ₃ rich in elastic equalizing - from the viewpoint of coating, it is bulky yarn such as woolly textured yarn and covering yarn preferable. Examples of the fiber material for forming the coated cloth 14 include natural fibers such as cellulose fiber, wool and silk; aliphatic polyamid fiber (nylon 66 fiber), aromatic polyamid fiber (para-based, meta-fiber). Examples thereof include synthetic fibers such as polyester fibers, acrylic fibers, and polyvinyl alcohol fibers. The fibrous material forming the coated cloth 14 preferably contains one or more of these, and may contain natural fibers and synthetic fibers from the viewpoint of suppressing the generation of abnormal noise when exposed to water. More preferably, it is more preferable to include cellulosic fibers and aliphatic polyamide fibers.

[0020] The content of the cellulosic fibers in the coating cloth 14 formed of the cellulosic fibers and the aliphatic polyamide fibers is preferably 50% from the viewpoint of suppressing the generation of abnormal noise when exposed to water. The content is preferably not less than mass% and not more than 90 mass%, more preferably not less than 60 mass% and not more than 80 mass%. Cellulosic fibers include, for example, softwood and hardwood wood pulp, bamboo fiber, sugar cane fiber, cotton fiber and kapok seed hair fiber, hemp, kouzo and mitsumata gin skin fiber, Manila hemp and New Zealand hemp leaf fiber, etc. Cellulose fibers derived from natural plants; cellulosic fibers derived from animals such as ascidian cellulose; bacterial cellulose fibers; cellulose fibers of algae; cellulose ester fibers; regenerated cellulose fibers such as rayon, kyupra and lyocell. 〇 2020/175 215 6 (:171? 2020/006079

[0021] The covering cloth 14 may be subjected to an adhesive treatment for imparting adhesiveness to the V-rib main body 118. As the adhesion treatment, an adhesive treatment in which the coated cloth 14 is immersed in an epoxy solution or an isocyanate solution and then pulled up and then heated, an adhesive treatment in which the coated cloth 14 is soaked in an aqueous solution and heated after being pulled up, the coated cloth 1 Examples of the adhesive treatment include immersing 4 in a low-viscosity rubber paste and then pulling it up and drying it, and coating the high-viscosity rubber glue on the V-rib body 1 13 side of the covering cloth 14 and then drying it. ..

A core wire 16 arranged so as to form a spiral having a pitch in the belt width direction is embedded in an intermediate portion of the adhesive rubber layer 12 in the belt thickness direction. The core wire 16 is composed of twisted yarns such as polyamid fiber, polyester fiber, aramid fiber, and polyamid fiber. The diameter of the core wire 16 is, for example, 〇.

5 Cores adjacent to each other 1 6

It is the following. The core wire 16 has an adhesive treatment in which it is immersed in an epoxy resin solution or an isocyanate resin solution and heated,

!_ It is preferable that at least one of the adhesive treatment of immersing in water solution and heating, and the immersing in rubber paste and drying is performed.

[0023] Fig. 2 shows a pulley layout of an accessory drive belt transmission 20 for an automobile using the V-ribbed belt according to the embodiment. This auxiliary drive belt transmission 20 is a serpentine drive system in which a V-ribbed belt is wound around six pulleys of four rib pulleys and two flat pulleys to transmit power.

[0024] In this accessory drive belt transmission 20, the rib steering power steering pulley 21 is provided at the uppermost position, and the rib pulley 80 generator bur 22 is provided below the power steering pulley 21. ing. A flat pulley tensioner pulley 23 is provided on the lower left side of the power steering pulley 21, and a flat pulley warp pump pulley 24 is provided below the tensioner pulley 23. In addition, the Tenshina Buri 2 3 〇 2020/175 215 7 (:171? 2020/006079

A crankshaft pulley 25, which is a rib pulley, is provided on the lower left side, and an air conditioner pulley 26, which is squeezed, is provided on the lower right of the crankshaft pulley 25. These pulleys are made of, for example, metal press-worked products, iron bars, or resin molded products such as nylon resin and phenol resin.

It is the following.

[0025] In this accessory drive belt transmission 20, the V-ribbed belt is wound around the power steering pulley 21 so that the V-rib 15 on the side of the compression rubber layer 11 contacts. , Wrap it around the tensioner pulley 23 so that the back side of the stretch rubber layer 13 side comes into contact, and then wrap it around the crankshaft pulley 25 and air conditioner pulley 26 so that the V rib 15 comes into contact. Furthermore, it is wound around the water pump pulley 24 so that the back side of the belt comes into contact, and then around the 80 generator bur 22 so that the V rib 15 comes into contact, and finally the power steering. It is provided so as to return to the pulley 21. The belt span length, which is the length of the V-ribbed belt that is stretched between the pulleys, is, for example, 50

It is the following. Misalignment that can occur between pulleys is 0 ^° or more and 2 ^° or less.

[0026] Next, a method for manufacturing the V-ribbed belt method according to the embodiment will be described.

[0027] FIG. 3 and FIG. 3 show a bridging device 30 used in the method for manufacturing a V-ribbed belt according to the embodiment. The cross-linking device 30 includes a base 31, a cylindrical expansion drum 32 standing upright on the base 31, and a cylindrical metal mold 33 provided outside thereof.

[0028] expansion drum 3 2 has a drum body 3 2 ₃ formed in a hollow cylindrical shape, and an outer-fitted a cylindrical rubber expansion sleeve 3 2 spoon on its outer periphery. The outer periphery of the drum body 3 2 _3, respectively, a large number of vent holes 3 2_Rei communicating with the inside is formed. Both ends of the expansion sleeve 32 are sealed by fixing rings 3 4 and 3 5 with the drum body 3 23, respectively. The crosslinked device 3 0, a high pressure inside the drum body 3 2 3 pressurizing means for pressurizing by introducing high pressure air (not shown) are provided inside the drum body 3 2 ₃ The pressing means air 〇 2020/175 215 8 (:171? 2020/006079

When high pressure air is introduced, high-pressure air enters between the drum body 3 2 3 and the〗彭彭轭罭 long sleeve 3 2 匕 through the ventilation hole 3 2 0 to expand the expansion sleeve 3 2 匕 radially outward. Is configured.

[0029] The cylindrical mold 33 is configured to be attachable to and detachable from the base 31. The cylindrical mold 33 attached to the base 31 is provided concentrically with the expansion drum 32 with a space therebetween. Cylindrical mold 3 3, on the inner peripheral surface, respectively, a plurality of V shape formed grooves 3 3 ₃ extending in the circumferential direction are formed continuously in the axial direction (the groove width direction). The bridging device 30 is provided with heating means and cooling means (neither shown) for the cylindrical mold 33, and these heating means and cooling means enable the temperature control of the cylindrical mold 33. Is configured to be.

[0030] In the method for manufacturing a V-ribbed belt according to the embodiment, first, each rubber compounding agent including a crosslinking agent is mixed with a rubber component, and the mixture is kneaded with a kneader such as a kneader or a Banbury mixer to obtain a rubber composition. The obtained uncrosslinked rubber composition is molded into a sheet by calendar molding or the like to prepare an uncrosslinked rubber sheet for the compressed rubber layer 11. Similarly, uncrosslinked rubber sheets for the adhesive rubber layer 12 and the stretched rubber layer 13 are also prepared. Further, the covering cloth 14 is prepared, and if necessary, an adhesive treatment is applied. The covering cloth 14 is preferably formed in a tubular shape. Furthermore, the core wire 16 is prepared, and the bonding treatment is performed if necessary.

[0031] Next, as shown in FIG. 48, a rubber sleeve 37 is placed on a cylindrical drum 36 having a smooth surface, and an uncrosslinked rubber sheet 13' for the stretched rubber layer 13 is provided thereon. And the uncrosslinked rubber sheet 12 ′ for the adhesive rubber layer 12 are sequentially wound and laminated, and the core wire 16 is spirally wound on the uncrosslinked rubber sheet 12 ′, and the uncrosslinked rubber sheet for the adhesive rubber layer 12 is further wound thereon. 1 2 ′, and the uncrosslinked rubber sheet 11 ′ for the compressed rubber layer 11 are wound in order, and finally, a non-crosslinked slab 3 ′ is formed by covering the unwrapped slab 3 ′.

[0032] Next, the rubber sleeve 37 provided with the uncrosslinked slab 3'is removed from the cylindrical drum 36, and as shown in Fig. 4B, it is fitted on the inner peripheral surface side of the cylindrical mold 33 and then, Place the cylindrical mold 33 with the uncrosslinked slab 3'of the 〇 2020/175 215 9 boxes (：171? 2020 /006079

Provide it and attach it to the base 31.

[0033] Subsequently, the cylindrical mold 33 is heated and, as shown in Fig. 40, a ventilation hole 322 is provided between the drum body 323 of the expansion drum 32 and the expansion sleeve 3213. High-pressure air is injected through the valve to inflate the expansion sleeve 32. At this time, the uncrosslinked slab 3'is pressed against the cylindrical mold 33, and the uncrosslinked rubber sheets 11', 12', and 13' press the covering cloth 14 to extend it to form a V shape. While flowing into the groove 3 33, the cross-linking of these rubber components proceeds and is integrated, and the rubber cloth component 14 and the core wire 16 are compounded, and the cylindrical belt slab 3 is molded. As a result, in each V shape forming groove 3 3 3 of the cylindrical mold 3 3, the V rib front structure including the V rib main body 1 13 formed of the rubber composition and the covering cloth 14 covering the entire surface thereof Form 1 5'. The molding temperature of this belt slab 3 is, for example, 100° or more and 180° or less, the molding pressure is, for example, 0.5 IV! 3 or more and 2.0 MPa or less, and the molding time is, for example, 10 minutes or more and 60 minutes or less. It is less than a minute.

[0034] Then, after the high pressure air is discharged from between the drum body 3 2 3 of the expansion drum 3 2 and the expansion sleeve 32, the belt slub 3 formed on the inner peripheral surface of the cylindrical mold 3 3 is removed. Taken out, as shown in Fig. 40, by grinding the covering cloth 14 at the tip of the V-rib front structure 15' formed on the belt slab 3 and removing it along the belt length direction, Both sides of the V-rib body 1 1 3 are covered with the covering cloth 14, and the V-rib body 1 1 3 is exposed at the tip end along the belt length direction to form the V-rib 15 5.

[0035] Finally, the belt slab 3 is sliced into a predetermined number of V ribs 15 and the front and back are turned upside down to obtain the V-ribbed belt sash according to the embodiment.

Example

[0036] (V-ribbed belt)

Rib belts of the following examples and comparative examples were produced.

[0037] <Example>

It has the same configuration as that of the above-mentioned embodiment, and is a knitted fabric formed of a composite spun yarn of nylon 66 fiber and cotton of cellulosic fiber as a covering fabric and is subjected to an adhesive treatment. 〇 2020/175 215 10 (:171? 2020/006079

A V-ribbed belt was manufactured using one that was not used, and this was used as an example. The V-ribbed belts of the practical example were manufactured with V-ribs of 2, 4, and 6, respectively. The belt main body was made of the Min. 01//1 composition, and the core wire was made of twisted polyester fiber.

[0038] <Comparative example>

A V-ribbed belt having the same structure as that of the example was prepared except that the entire surface of the V-ribbed body was covered with a covering cloth, and the rubber composition of the V-ribbed body was not exposed at the tip end. did.

[0039] (Test method)

The ▽ribbed belts of Examples and Comparative Examples were subjected to the following water injection transmission capacity test and power loss test.

[0040] <Water injection transmission capacity test>

Figure 5 shows the pulley layout of the belt running tester 40 for the water injection transmission capacity test.

[0041] This belt running tester 40 has a pulley diameter of 1 2 1.

The first drive pulley 41 of the rib pulley is provided, and the second drive pulley 42 of the rib pulley is provided to the right of the first drive pulley 41. The pulley diameter is diagonally above and right of the second drive pulley 42.

The first driven pulley 43 of the rib pulley is provided, and the pulley diameter is 61.

A second driven pulley 4 4 of 0 rib pulley is provided. The pulley diameter between the first drive pulley 41 and the second driven pulley 44 is 7 6.

The first idler pulley 45 of the flat pulley is provided, and the pulley diameter is 76.2 between the first driven pulley 4 3 and the second driven pulley 4 4.

The second idler pulley 46 of the flat pulley is provided. The second driven pulley 44 is movably provided up and down, and is configured to be able to bear an axial load.

[0042] Regarding the V-ribbed belt having six V-ribs in each of the example and the comparative example, the first and second drive pulleys 41, 42 are arranged side by side so that the V-rib side contacts. Wrap it around the 1st and 2nd driven pulleys 4 3 and 4 4 and stretch the rubber layer. 〇 2020/175 215 1 1 卩(：171? 2020/006079

The first and second idler pulleys 4 5 and 4 6 were wound so that the sides contacted with each other, and a belt tension was applied to the second driven pulley 4 4 by applying an axial load of 7 0 6 1\1 upward. The wrap angle of the V-ribbed belt on the second drive pulley 42 was 39°. Next, in a temperature atmosphere of 21°, the first drive pulley 41 is rotated in the same direction at each rotation speed of 800 ″ and the second drive pulley 42 is 931 ″, whereby the first drive pulley 41 is rotated in the same direction. 2 Forcibly slipped the V-ribbed belt on the drive pulley 4 2. Also, the V-ribbed surface on the right-hand side of the first drive pulley 4 1 at the beginning of the winding of the V-ribbed belt was 3 minutes per minute.

A drop of water was added at a rate of I. Then, the maximum value of the generated torque was measured by the torque meter provided on the second drive pulley 42.

[0043] <Power loss test>

FIG. 6 and Tami show a belt power loss measuring device 50.

[0044] This belt power loss measuring device 50 has a pulley diameter of 5

The drive pulley 51 of the rib pulley and the pulley diameter on the right side are

It is equipped with a driven pulley 52 of the Riburi. The drive pulley 5 1 is attached to one end of the drive shaft 5 1 rotatably provided by a pair of spindle bases 5 1 3 provided at intervals, and the other end of the drive shaft 5 1 Is equipped with a rotation imparting pulley 510. On the right side of the rotation imparting pulley 5 100, a motor pulley 5 3 swivel supported by a motor shaft 5 3 3 of the drive motor 5 3 is provided.The rotation imparting pulley 5 1 0 and the motor pulley 5 3 3 A rotary drive belt 54 is wound around the space. A torque meter 55 for detecting the rotating torque of the drive shaft 5113 is provided between the pair of spindle bases 513. The driven pulley 52 is attached to one end of a drive shaft 5213 that is rotatably provided by a pair of spindle bases 523 that are spaced apart from each other. Has been.

[0045] A V-ribbed belt having two V-ribs in each of the example and the comparative example was wound around the drive pulley 5 1 and the driven pulley 52, and the driven pulley 52 was moved to the right side. Load a dead weight (○) of 600!\1 in a room temperature atmosphere. 〇 2020/175 215 12 (:171? 2020/006079

In the air, the drive motor 5 3 rotates the drive pulley 5 1 at a rotational speed of 300 ″ to drive the belt, and the drive torque at that time was measured by the torque meter 5 5. Similarly, The driving torque was also measured for V-ribbed belts with the number of 4 and 6. In order to measure the stable driving torque by eliminating the influence of heat generation, etc., the measurement was performed after 1 hour of belt running. ..

[0046] On the other hand, for each of the V-ribbed belts having 2, 4, and 6 V-ribs, the belt bending stiffness was obtained by using the Olsen bending tester in the same manner as above. ..

[0047] Next, the measured values were plotted on a graph in which the horizontal axis represents the belt bending rigidity and the vertical axis represents the driving torque, and a linear approximation was made. Imagined the torque, the loss torque was subtracted from each measured value of the driving torque. Then, they were converted to power, and the results were divided by the number of V ribs, and the average was calculated to obtain the belt power loss per belt width for one V rib.

[0048] (Test results)

FIG. 7 shows the maximum torque in the water injection power transmission capacity test of Examples and Comparative Examples. FIG. 8 shows the power loss in the power loss test of Examples and Comparative Examples.

According to these, although the maximum torque in the water injection transmission capacity test is the same in the example and the comparative example, the power loss in the power loss test is lower in the example than in the comparative example.

Industrial availability

[0050] The present invention relates to a V-ribbed belt and a method for manufacturing the same. Explanation of symbols

[0051] Mimi V Ribbed Belt

1 1 3 V rib body

1 2 Adhesive rubber layer

1 4 coated cloth

1 5 V rib \¥02020/175215 13 (: 17 2020 /006079

15 V rib front structure

Claims

\¥0 2020/175 215 14 (: 17 2020/006079 Claims

[Claim 1] A V-ribbed belt having a plurality of V-ribs,

Each of the plurality of V ribs includes a V rib main body formed of a rubber composition, and a covering cloth that covers both side surfaces of the V rib main body, and has a tip portion along the belt length direction. A V-rib rib with exposed V-rib body.

[Claim 2] In the V-ribbed belt according to claim 1,

A V-ribbed belt in which the V-rib body is exposed as a surface at the tip of each of the plurality of V-ribs.

[Claim 3] In the V-ribbed belt according to claim 1 or 2,

A V-ribbed belt in which the exposed width of the V-rib body is 35% or more and 70% or less of the width between the rib base ends of the V-ribs.

[Claim 4] A method for manufacturing a V-ribbed belt having a plurality of V-ribs,

A V-rib front structure including a V-rib main body formed of a rubber composition and a covering cloth covering the entire surface of the V-rib main body is formed, and the covering cloth at the front end of the V-rib front structure is formed into a belt. By removing along the length direction, both side surfaces of the V-rib body are covered with the covering cloth, and the V-rib is formed at the tip end portion of the V-rib body where the V-rib body is exposed along the belt length direction. V ribbed belt manufacturing method.