WO2018043316A1

WO2018043316A1 - Method for manufacturing cogged v-belts

Info

Publication number: WO2018043316A1
Application number: PCT/JP2017/030465
Authority: WO
Inventors: 三浦　義弘; 高場　晋
Original assignee: 三ツ星ベルト株式会社
Priority date: 2016-08-29
Filing date: 2017-08-25
Publication date: 2018-03-08

Abstract

The present invention pertains to a method for manufacturing cogged v-belts that are provided with, on the inner circumference of a belt, a plurality of cogs that are disposed to extend in the width direction of the belt and to be spaced apart from each other in the belt longitudinal direction, wherein the method for manufacturing cogged v-belts comprises: a unvulcanized sleeve forming step of forming an unvulcanized sleeve by layering a plurality of unvulcanized rubber sheets that contain at least an unvulcanized rubber sheet for a compression rubber layer that is a compression rubber layer disposed on the inner circumferential side of the belt and an unvulcanized rubber sheet for an expansion rubber layer that is an expansion rubber layer disposed on the outer circumferential side of the belt; a vulcanized sleeve forming step of forming a vulcanized sleeve by vulcanizing the unvulcanized sleeve after the unvulcanized sleeve forming step; and a cog forming step of forming the plurality of cogs on the compression rubber layer after the vulcanized sleeve forming step.

Description

Manufacturing method of V belt with cogs

The present invention relates to a method for manufacturing a cogged V-belt in which a plurality of cogs extending in the belt width direction and spaced apart from each other in the belt longitudinal direction are provided on the inner circumferential side of the belt.

V-belts with cogs have excellent flexibility due to multiple cogs, and are applied to general industrial machinery, agricultural machinery, snowmobiles, motorcycles, automobile accessory drive systems, etc., and also to continuously variable transmissions Sometimes it is done.

In the manufacturing method of the cogged V-belt, a cylindrical drum having irregularities on the outer peripheral surface is used, and a plurality of unvulcanized rubber sheets (compressed rubber layer, back rubber layer (extension rubber) are formed on the outer peripheral surface of the drum. After forming an unvulcanized sleeve by wrapping an unvulcanized rubber sheet) to become a layer), etc., the unvulcanized sleeve was heated and pressurized to form a plurality of cogs corresponding to the irregularities of the drum A technique for obtaining a vulcanized sleeve is known (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-153558

In the above manufacturing method, when the unvulcanized sleeve is pressurized, the unvulcanized rubber sheet for the compressed rubber layer that becomes the compressed rubber layer flows along the irregularities of the drum. At this time, the flow mode of the unvulcanized rubber sheet for the compressed rubber layer differs between the concave portion and the convex portion of the drum, or the unvulcanized rubber when the unvulcanized rubber sheet for the compressed rubber layer flows into the concave portion of the drum. The flow of the unvulcanized rubber sheet for the compressed rubber layer can be non-uniform by winding another unvulcanized rubber sheet on the belt outer periphery side with respect to the sheet. In this case, in the vulcanization sleeve, the thickness of the cogged portion (cog portion) in the compressed rubber layer becomes non-uniform. For example, a dent is generated on the outer peripheral side of the belt of the cogged portion in the compressed rubber layer. Another rubber layer made of the other unvulcanized rubber sheet may enter. When such a cogged V-belt is used, a crack starting from a dent is generated at the interface between the compressed rubber layer and another rubber layer, and the compressed rubber layer can be peeled off from the other rubber layer.

An object of the present invention is to provide a manufacturing method of a cogged V-belt that can suppress generation of cracks starting from a dent of the compressed rubber layer and peeling of the compressed rubber layer.

According to the present invention, in the method of manufacturing a V-belt with a cog in which a plurality of cogs extending in the belt width direction and spaced apart from each other in the belt longitudinal direction are provided on the belt inner circumferential side, A plurality of unvulcanized rubbers including at least a non-vulcanized rubber sheet for a compressed rubber layer to be a compressed rubber layer disposed on the side and an unvulcanized rubber sheet for a stretched rubber layer to be a stretched rubber layer disposed on the outer peripheral side of the belt An unvulcanized sleeve forming step of laminating sheets to form an unvulcanized sleeve, and a vulcanized sleeve forming of a vulcanized sleeve by vulcanizing the unvulcanized sleeve after the unvulcanized sleeve forming step And a cog forming step of forming the plurality of cogs on the compressed rubber layer after the vulcanized sleeve forming step.

The present invention is not a method in which the unvulcanized sleeve is pressurized and the unvulcanized rubber sheet for the compressed rubber layer is flowed to form a plurality of cogs, but the unvulcanized sleeve is vulcanized and vulcanized. A method of forming a plurality of cogs after forming the sleeve is employed. Therefore, the problem that the flow of the unvulcanized rubber sheet for the compressed rubber layer becomes uneven and the dent on the outer peripheral side of the belt of the cog portion in the compressed rubber layer is suppressed, and as a result, the dent of the compressed rubber layer is the starting point. Generation | occurrence | production of a crack and peeling from another rubber layer of a compression rubber layer can be suppressed.

The unvulcanized rubber sheet for the compressed rubber layer laminated in the unvulcanized sleeve forming step may include short fibers oriented in the belt width direction. According to the above configuration, by orienting the short fibers in the belt width direction, high anisotropy can be obtained, and the elastic modulus in the belt width direction can be increased to effectively improve the side pressure resistance. In particular, when applied to a continuously variable transmission, the cogged V-belt is greatly bent and used in a harsh layout under a high load. Therefore, high durability and fuel saving (transmission) are required. In this respect, according to the above configuration, the side pressure resistance (deformation resistance due to side pressure), which is one of the important factors responsible for both durability and fuel efficiency, can be improved. Therefore, the present invention can be suitably applied to a continuously variable transmission that requires high-load transmission. Moreover, in the structure which mix | blended the short fiber with the compression rubber layer, it pressurizes with respect to an unvulcanized sleeve like patent document 1, and makes the unvulcanized rubber sheet for compression rubber layers flow, and forms a plurality of cogs When this method is adopted, the flow of the unvulcanized rubber sheet for the compressed rubber layer becomes nonuniform, and the orientation of the short fibers is disturbed. In this regard, the present invention is not a method in which the unvulcanized sleeve is pressurized to flow the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs, but the unvulcanized sleeve is vulcanized. Since the method of forming a plurality of cogs after forming a vulcanized sleeve, the problem of non-uniform flow of the unvulcanized rubber sheet for the compressed rubber layer is suppressed, and the orientation of short fibers Disturbance is also suppressed.

In the unvulcanized sleeve forming step, the unvulcanized rubber sheet for the compressed rubber layer may include a plurality of sheet members each including the short fibers and laminated to each other. According to the said structure, compared with the case where a short fiber is orientated to one sheet member and it is used as an unvulcanized rubber sheet for compression rubber layers, a short fiber is each provided in each of several sheet members with comparatively small thickness. By aligning and laminating them, the short fibers can be easily oriented. Further, in a configuration in which the unvulcanized rubber sheet for the compressed rubber layer includes a plurality of sheet members, the unvulcanized sleeve for the compressed rubber layer is caused to flow by applying pressure to the unvulcanized sleeve as in Patent Document 1. When the method of forming a plurality of cogs is employed, the flow of the unvulcanized rubber sheet for the compressed rubber layer becomes non-uniform, and separation may occur between the plurality of sheet members when the belt is used. In this regard, the present invention is not a method in which the unvulcanized sleeve is pressurized to flow the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs, but the unvulcanized sleeve is vulcanized. Since the method of forming a plurality of cogs after forming a vulcanized sleeve, the problem of non-uniform flow of the unvulcanized rubber sheet for the compressed rubber layer is suppressed, and a plurality of sheet members Peeling is unlikely to occur.

In the unvulcanized sleeve forming step, an unvulcanized rubber sheet for an adhesive rubber layer serving as an adhesive rubber layer is provided between the unvulcanized rubber sheet for the compressed rubber layer and the unvulcanized rubber sheet for the stretch rubber layer. May be arranged. When the method of applying pressure to the unvulcanized sleeve and flowing the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs as in Patent Document 1, the unvulcanized for the compressed rubber layer is employed. When the rubber sheet flows into the concave portion of the drum, the unvulcanized rubber sheet for the adhesive rubber layer is wound, and a dent is generated on the outer peripheral side of the belt of the cogged portion in the compressed rubber layer, and the adhesive rubber layer enters the dent. In this regard, the present invention is not a method in which the unvulcanized sleeve is pressurized to flow the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs, but the unvulcanized sleeve is vulcanized. The method of forming multiple cogs after forming the vulcanized sleeve prevents problems such as entanglement of the unvulcanized rubber sheet for the adhesive rubber layer and penetration of the adhesive rubber layer into the recess. In addition, cracks starting from the dents are unlikely to occur at the interface between the compressed rubber layer and the adhesive rubber layer, and peeling of the compressed rubber layer from the adhesive rubber layer is also suppressed.

In the unvulcanized sleeve forming step, a core wire extending in the belt longitudinal direction may be disposed in the unvulcanized rubber sheet for the adhesive rubber layer. According to the above configuration, the core wire is buried in the adhesive rubber layer, and the durability is improved as compared with the case where the core wire is not buried in the adhesive rubber layer and is only in contact with the adhesive rubber layer.

FIG. 1 is a perspective sectional view showing a cogged V-belt according to an embodiment of the present invention. FIGS. 2A and 2B are cross-sectional views showing an example in which a cogged V-belt according to an embodiment of the present invention is applied to a continuously variable transmission. FIG. 3 is a flowchart showing a method for manufacturing a cogged V-belt according to an embodiment of the present invention. FIG. 4 is a graph showing a running pattern of an actual vehicle in the durability running test of the cogged V-belt according to the example and the comparative example. FIG. 5A is a schematic diagram illustrating a side surface of a cogged V-belt according to a comparative example after the durability running test. FIG. 5B is a schematic view showing a side surface of the cogged V-belt according to the example after the durability running test.

As shown in FIG. 1, the cogged V-belt 1 according to an embodiment of the present invention includes a reinforcing cloth 2, a stretch rubber layer 3, an adhesive rubber layer 4, and a belt from the belt outer peripheral side 1 y toward the belt inner peripheral side 1 x. It has a structure in which the compressed rubber layers 5 are sequentially laminated. A core wire 4a extending in the longitudinal direction of the belt is embedded in the adhesive rubber layer 4.

The stretch rubber layer 3, the adhesive rubber layer 4 and the compression rubber layer 5 are formed of a rubber composition containing a rubber component. Furthermore, the rubber composition constituting the stretched rubber layer 3 and the compressed rubber layer 5 includes short fibers.

As the rubber component, a vulcanizable or crosslinkable rubber may be used, for example, a diene rubber (natural rubber, isoprene rubber, butadiene rubber, chloroprene rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (nitrile rubber), Hydrogenated nitrile rubber, etc.), ethylene-α-olefin elastomer, chlorosulfonated polyethylene rubber, alkylated chlorosulfonated polyethylene rubber, epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, fluororubber, or You may use what combined 2 or more types. Preferred rubber components are ethylene-α-olefin elastomers (ethylene-propylene copolymer (EPM), ethylene-propylene-diene terpolymer (EPDM), etc.), and chloroprene rubber. A particularly preferred rubber component is chloroprene rubber. The chloroprene rubber may be either a sulfur-modified type or a non-sulfur-modified type.

Additives may be added to the rubber composition. Examples of the additive include a vulcanizing agent or a crosslinking agent (or a crosslinking agent system) (sulfur-based vulcanizing agent, etc.), a co-crosslinking agent (bismaleimides, etc.), a vulcanization aid or a vulcanization accelerator (thiuram-based). Accelerators), vulcanization retarders, metal oxides (zinc oxide, magnesium oxide, calcium oxide, barium oxide, iron oxide, copper oxide, titanium oxide, aluminum oxide, etc.), enhancers (for example, carbon black, water content) Silicon oxides such as silica), fillers (clay, calcium carbonate, talc, mica, etc.), softeners (for example, oils such as paraffin oil and naphthenic oil), processing agents or processing aids (stearic acid, stearin) Acid metal salts, wax, paraffin, fatty acid amide, etc.), anti-aging agents (antioxidants, thermal anti-aging agents, anti-bending agents, anti-ozone agents, etc.), colorants, tackifiers, plastics , Coupling agents (silane coupling agent, etc.), stabilizers (UV absorbers, heat stabilizers, etc.), flame retardants, may be used a combination antistatic agent, one or more of. The metal oxide may act as a crosslinking agent. In particular, the rubber composition constituting the adhesive rubber layer 4 may contain an adhesion improver (resorcin-formaldehyde cocondensate, amino resin, etc.).

Examples of the short fibers include polyolefin fibers (polyethylene fibers, polypropylene fibers, etc.), polyamide fibers (polyamide 6 fibers, polyamide 66 fibers, polyamide 46 fibers, aramid fibers, etc.), polyalkylene arylate fibers (for example, polyethylene terephthalate ( PET) fiber, polyethylene naphthalate (PEN) fiber, etc., C _2-4 alkylene C _6-14 arylate fiber), vinylon fiber, polyvinyl alcohol fiber, polyparaphenylene benzobisoxazole (PBO) fiber, etc. A combination of one or more of natural fibers such as cotton, hemp, and wool; inorganic fibers such as carbon fibers may be used. In order to improve the dispersibility and adhesiveness in the rubber composition, the short fibers may be subjected to a conventional adhesion treatment (or surface treatment). May be processed.

The rubber composition constituting the stretch rubber layer 3, the adhesive rubber layer 4 and the compression rubber layer 5 may be the same as each other or different from each other. Similarly, the short fibers contained in the stretch rubber layer 3 and the compressed rubber layer 5 may be the same as each other or different from each other.

In the adhesive rubber layer 4, a plurality of core wires 4a extend in the belt longitudinal direction and are spaced apart from each other at a predetermined pitch in the belt width direction.

The core wire 4a is made of, for example, a twisted cord using multifilament yarn (for example, various twists, single twists, rung twists). The average wire diameter (fiber diameter of the twisted cord) of the core wire 4a may be, for example, about 0.5 to 3 mm, preferably about 0.6 to 2.0 mm, and more preferably about 0.7 to 1.5 mm.

As the fibers constituting the core wire 4a, the fibers exemplified as the short fibers may be used. From the viewpoint of high modulus, the fibers constituting the core 4a include polyamide fibers (polyamide 6 fibers, polyamide 66 fibers, polyamide 46 fibers, aramid fibers, etc.), polyalkylene arylate fibers (for example, polyethylene terephthalate (PET) fibers, Synthetic fibers such as polyethylene naphthalate (PEN) fibers, C _2-4 alkylene C _6-14 arylate fibers); inorganic fibers such as carbon fibers may be used, particularly polyamide fibers and polyalkylene arylate fibers. It is preferable to use it. The fiber constituting the core wire 4a may be a multifilament yarn. The fineness of the core wire 4a composed of the multifilament yarn may be, for example, about 2000 to 10000 denier (particularly 4000 to 8000 denier). The multifilament yarn may include, for example, about 100 to 5000, preferably 500 to 4000, and more preferably about 1000 to 3000 monofilament yarns. The core wire 4a may be subjected to a conventional adhesion treatment (or surface treatment) as in the case of the short fibers.

The reinforcing cloth 2 is made of a cloth material such as woven cloth, wide-angle sail cloth, knitted cloth, non-woven cloth (preferably woven cloth). The reinforcing cloth 2 is subjected to an adhesive treatment (for example, an immersion treatment with an RFL solution) on the cloth material, and a friction process in which the rubber composition is rubbed into the cloth material or a process of laminating the sheet-like rubber composition and the cloth material. After that, it may be laminated on the surface of the stretch rubber layer 3.

The cross section perpendicular to the belt longitudinal direction of the V-belt 1 with cogs has an inverted trapezoidal shape in which the belt width decreases from the belt outer peripheral side 1y toward the belt inner peripheral side 1x. A plurality of cogs 1a are formed on the inner circumferential side 1x of the V belt 1 with cogs. The plurality of cogs 1a are formed in the compressed rubber layer 5, and extend in the belt width direction and are spaced apart from each other in the belt longitudinal direction.

The cogged V-belt 1 is applicable to a continuously variable transmission 30 as shown in FIG.

The continuously variable transmission 30 includes a drive pulley 31 and a driven pulley 32 having V-shaped

grooves

31x and 32x, respectively, into which the cogged V-belt 1 is fitted. The cogged V-belt 1 is wound with tension applied to the driving pulley 31 and the driven pulley 32 to define both side surfaces 1z of the cogged V-belt 1 and

grooves

31x and 32x of the driving pulley 31 and the driven pulley 32, respectively. The vehicle travels in a state where both

side surfaces

31z and 32z are in contact with each other. The torque of the drive pulley 31 is transmitted to the driven pulley 32 via the cogged V-belt 1 due to the frictional force between both side surfaces generated at this time.

The driving pulley 31 and the driven pulley 32 are attached to fixed

pulley pieces

31a and 32a having

rotating shafts

31t and 32t, respectively, so as to be movable in the direction along the rotating

shafts

31t and 32t with respect to the fixed

pulley pieces

31a and 32a.

Movable pulley pieces

31b and 32b. The

movable pulley pieces

31b and 32b are formed between the fixed

pulley pieces

31a and 32a and the

movable pulley pieces

31b and 32b by moving in the direction along the

rotation shafts

31t and 32t with respect to the fixed

pulley pieces

31a and 32a. The width of the

groove

31x, 32x changes. The position of the cogged V-belt 1 in the

grooves

31x and 32x changes according to the change in the width of the

grooves

31x and 32x. For example, when the state shown in FIG. 2 (a) is changed to the state shown in FIG. 2 (b) (that is, the width of the groove 31x is narrow and the width of the groove 32x is wide), the cogged V-belt 1 Is moved away from the rotating shaft 31t, and the groove 32x moves closer to the rotating shaft 32t. Thereby, the winding radius of the cogged V-belt 1 in the drive pulley 31 and the driven pulley 32 changes. The continuously variable transmission 30 is configured to change the speed ratio steplessly by continuously changing the winding radius in this way.

Next, a method for manufacturing the cogged V-belt 1 will be described with reference to FIG.

The manufacturing method according to the present embodiment includes an unvulcanized sleeve forming step S1, a vulcanized sleeve forming step S2, a cog-free V-belt forming step S3, and a cog forming step S4.

The unvulcanized sleeve forming step S1 is a step of forming an annular unvulcanized sleeve. In the unvulcanized sleeve forming step S1, a cylindrical drum is used, and on the outer peripheral surface of the drum, the unvulcanized rubber sheet for the compressed rubber layer that becomes the compressed rubber layer 5, the compressed rubber layer 5 in the adhesive rubber layer 4, and Unvulcanized rubber sheet for the first adhesive rubber layer to be in contact, core 4a, unvulcanized rubber sheet for the second adhesive rubber layer to be in contact with the stretch rubber layer 3 in the adhesive rubber layer 4, stretch rubber The unvulcanized rubber sheet for the stretch rubber layer and the reinforcing cloth 2 to be the layer 3 are laminated in order. In addition, the unevenness | corrugation corresponding to several cogs 1a is not provided in the outer peripheral surface of the said drum.

Specifically, in the unvulcanized sleeve forming step S1, first, a plurality of sheet members including short fibers and laminated together are used as unvulcanized rubber sheets for the compressed rubber layer, and the short fibers of each sheet member are belted. Oriented in the width direction and wound on a cylindrical drum (S1a). Thereafter, the unvulcanized rubber sheet for the first adhesive rubber layer is laminated on the unvulcanized rubber sheet for the compressed rubber layer (S1b). Thereafter, the core 4a is spun spirally on the unvulcanized rubber sheet for the first adhesive rubber layer (S1c). Thereafter, an unvulcanized rubber sheet for the second adhesive rubber layer is laminated on the core wire 4a (S1d). Thereafter, the unvulcanized rubber sheet for the stretch rubber layer is laminated on the unvulcanized rubber sheet for the second adhesive rubber layer (S1e). Thereafter, the reinforcing cloth 2 is laminated on the unvulcanized rubber sheet for the stretch rubber layer (S1f).

Here, the average length of the short fibers contained in the sheet member is preferably in the range of 1 to 20 mm, more preferably in the range of 1.2 to 15 mm, and further preferably in the range of 2 to 6 mm. The reason for this is that if the average length of the short fibers is too short, the mechanical properties (for example, the modulus) in the line direction may not be sufficiently improved. This is because there is a possibility that the fiber is poorly dispersed, the rubber is cracked, and the belt is damaged early.

The average fiber diameter of the short fibers is preferably in the range of 1 to 100 μm, more preferably in the range of 3 to 50 μm, and further preferably in the range of 5 to 30 μm. The reason is that if the average fiber diameter is too large, the mechanical properties of the compressed rubber layer may be lowered, and if it is too small, the surface friction coefficient may not be sufficiently reduced.

Further, the blending amount (ratio) of the short fibers is preferably 30 parts by mass or less, more preferably 8 to 30 parts by mass, and further preferably 10 to 28 parts by mass with respect to 100 parts by mass of the rubber component. It is preferably 12 to 25 parts by mass. The reason for this is that if the proportion of short fibers is too small, the mechanical properties of the compressed rubber layer may be reduced. On the other hand, if the proportion is too large, in addition to the reduction in transmission efficiency, dispersion of the short fibers in the rubber composition may occur. This is because there is a possibility that cracking may occur at an early stage in the compressed rubber layer starting from that point.

Further, it is preferable to use a sheet member laminated as an unvulcanized rubber sheet for a compressed rubber layer having a thickness of 0.2 to 2.5 mm, preferably 0.5 to 1.6 mm. An unvulcanized rubber sheet for a compressed rubber layer is formed by laminating sheet members having a thickness in the left range to a predetermined thickness.

The vulcanized sleeve forming step S2 is a step of forming an annular vulcanized sleeve by vulcanizing the obtained unvulcanized sleeve after the unvulcanized sleeve forming step S1. In the vulcanization sleeve forming step S2, a known method may be employed. For example, a vulcanization jacket is placed on the outside of the unvulcanized sleeve and a mold is placed on the vulcanization can, and the temperature is 120 to 200 ° C. The unvulcanized sleeve may be vulcanized at about ~ 180 ° C.

The cogless V-belt forming step S3 is a step of forming an annular cog-free (no cog 1a) V-belt after the vulcanization sleeve forming step S2. In the cogless V-belt forming step S3, the vulcanization jacket and the vulcanization sleeve are extracted from the vulcanization can, then the vulcanization sleeve is cut to a predetermined width, and the side is cut with a cutter or the like so as to obtain a predetermined V angle. By doing so, a coggless V-belt is formed.

The cog forming step S4 is a step of forming a plurality of cogs 1a on the compressed rubber layer 5 after the cogless V-belt forming step S3. That is, the cogs 1a are not formed in the steps S1 to S3, and the cogs 1a are formed in the step S4.

In the cog forming step S4, an arbitrary method may be adopted, for example, a water jet processing machine may be used. An example of a procedure for forming the cogs 1a using a water jet processing machine will be described below.

First, a wooden plate, a plastic plate, and a metal plate are arranged in this order on a water tank of a water jet processing machine and fixed with tape or the like. And the four reference holes and the groove | channel of the same shape as the belt inner peripheral side 1x containing several cogs 1a are formed in the metal plate arrange | positioned at the uppermost layer with a water jet. The four reference holes correspond to the four pin holes formed in the cylindrical belt fixing jig to which the annular cogless V-belt is fixed. After that, the annular cogless V-belt formed in S3 is attached to the belt fixing jig with the compression rubber layer 5 on the outside and the stretch rubber layer 3 on the inside, and the belt fixing jig is installed on the metal plate. Pins are inserted into the four pin holes and the four reference holes of the fixing jig to fix the belt fixing jig to the metal plate. Thereafter, the control unit of the water jet processing machine reads the data related to the shape of the belt inner peripheral side 1x including the plurality of cogs 1a, inputs the processing conditions such as the belt thickness and the processing speed, and performs the processing.

As described above, according to the present embodiment, it is not a method of forming a plurality of cogs 1a by applying pressure to the unvulcanized sleeve and causing the unvulcanized rubber sheet for the compressed rubber layer to flow. A method of forming a plurality of cogs 1a after vulcanizing an unvulcanized sleeve to form a vulcanized sleeve is employed (see S1 to S4 in FIG. 3). Therefore, the problem that the flow of the unvulcanized rubber sheet for the compressed rubber layer becomes uneven and the dent on the belt outer peripheral side 1y of the cog portion in the compressed rubber layer 5 is suppressed, and as a result, the dent of the compressed rubber layer 5 is reduced. Generation of cracks as a starting point and peeling of the compressed rubber layer 5 from another rubber layer (the adhesive rubber layer 4 in the present embodiment) can be suppressed.

In the present embodiment, in the unvulcanized sleeve forming step S1, the unvulcanized rubber sheet for compressed rubber layer containing short fibers is used to orient the short fibers in the belt width direction (see S1a in FIG. 3). According to the above configuration, by orienting the short fibers in the belt width direction, high anisotropy can be obtained, and the elastic modulus in the belt width direction can be increased to effectively improve the side pressure resistance. In particular, when applied to the continuously variable transmission 30, the cogged V-belt 1 is greatly bent and used in a harsh layout under a high load, so that high durability and fuel saving (transmission) are required. . In this respect, according to the above configuration, the side pressure resistance (deformation resistance due to side pressure), which is one of the important factors responsible for both durability and fuel efficiency, can be improved. Therefore, the present invention can be suitably applied to the continuously variable transmission 30 or the like that requires high load transmission. Moreover, in the structure which mix | blended the short fiber with the compression rubber layer 5, it pressurizes with respect to an unvulcanized sleeve like patent document 1, and makes the unvulcanized rubber sheet for compression rubber layers flow, and the several cogs 1a are made. When the method of forming is adopted, the flow of the unvulcanized rubber sheet for the compressed rubber layer becomes non-uniform so that the orientation of the short fibers is disturbed. In this regard, in this embodiment, the unvulcanized sleeve is not a method of pressurizing the unvulcanized sleeve to flow the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs 1a. Since a method of forming a plurality of cogs 1a after forming a vulcanized sleeve by vulcanization, the problem of non-uniform flow of the unvulcanized rubber sheet for the compressed rubber layer is suppressed, and the short Disturbance of fiber orientation is also suppressed.

In the present embodiment, in the unvulcanized sleeve forming step S1, a plurality of sheet members each containing short fibers and laminated together are used as unvulcanized rubber sheets for the compressed rubber layer (see S1a in FIG. 3). According to the said structure, compared with the case where a short fiber is orientated to one sheet member and it is used as an unvulcanized rubber sheet for compression rubber layers, a short fiber is each provided in each of several sheet members with comparatively small thickness. By aligning and laminating them, the short fibers can be easily oriented. Further, in a configuration in which the unvulcanized rubber sheet for the compressed rubber layer includes a plurality of sheet members, the unvulcanized sleeve for the compressed rubber layer is caused to flow by applying pressure to the unvulcanized sleeve as in Patent Document 1. When the method of forming the plurality of cogs 1a is employed, the flow of the unvulcanized rubber sheet for the compressed rubber layer becomes non-uniform, and separation may occur between the plurality of sheet members when the belt is used. In this respect, in the present invention, the unvulcanized sleeve is vulcanized, not a method in which the unvulcanized sleeve is pressurized to flow the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs 1a. Since the method of forming the plurality of cogs 1a after forming the vulcanized sleeve is adopted, the problem of non-uniform flow of the unvulcanized rubber sheet for the compressed rubber layer is suppressed, and a plurality of cogs 1a are formed. Peeling hardly occurs between sheet members.

In the present embodiment, in the unvulcanized sleeve forming step S1, the unvulcanized rubber sheet for the adhesive rubber layer is disposed between the unvulcanized rubber sheet for the compression rubber layer and the unvulcanized rubber sheet for the stretch rubber layer ( (See S1a to S1e in FIG. 3). When the method of forming a plurality of cogs 1a by applying pressure to the unvulcanized sleeve and flowing the unvulcanized rubber sheet for the compressed rubber layer as in Patent Document 1, the unvulcanized for the compressed rubber layer is formed. When the vulcanized rubber sheet flows into the concave portion of the drum, the unvulcanized rubber sheet for the adhesive rubber layer is wound, and a dent is formed on the belt outer peripheral side 1y of the cogged portion in the compressed rubber layer 5, and the adhesive rubber layer 4 enters the dent. It can be a state. In this regard, in this embodiment, the unvulcanized sleeve is not a method of pressurizing the unvulcanized sleeve to flow the unvulcanized rubber sheet for the compressed rubber layer to form a plurality of cogs 1a. Since a method of forming a plurality of cogs 1a after forming a vulcanized sleeve by vulcanization, the unvulcanized rubber sheet for the adhesive rubber layer is entangled, the adhesive rubber layer 4 enters into the recess, etc. The problem is suppressed, cracks starting from the dents are unlikely to occur at the interface between the compressed rubber layer 5 and the adhesive rubber layer 4, and peeling of the compressed rubber layer 5 from the adhesive rubber layer 4 is also suppressed.

In the unvulcanized sleeve forming step S1, the core wire 4a extending in the longitudinal direction of the belt is disposed in the unvulcanized rubber sheet for the adhesive rubber layer (see S1b to S1d in FIG. 3). According to the above configuration, the core wire 4 a is buried in the adhesive rubber layer 4, and the durability is higher than the case where the core wire 4 a is not buried in the adhesive rubber layer 4 and is only in contact with the adhesive rubber layer 4. Will improve.

A cog-attached V-belt (Examples 1 to 7) manufactured by the same manufacturing method as in the above-described embodiment and a cog-attached V-belt (Comparative Examples 1 to 4) manufactured by the same manufacturing method as Patent Document 1 A U / D (UP / DOWN) durability running test was performed, and the state of the side surface of each cogged V-belt after the test was compared. Table 1 shows the configuration of the V-belt with cogs according to Examples 1 to 7, and Table 2 shows the configuration of the V-belt with cogs according to Comparative Examples 1 to 4.

Examples 1 and 2 are examples in which the average fiber length of short fibers is varied using the same constituent materials.
Example 3 is an example in which the average fiber diameter of short fibers is varied using the same constituent materials as in Example 1.
Example 4 is an example in which the blending amount of the short fibers is changed using the same constituent materials as in Example 1.
Example 5 is an example in which the average fiber length of short fibers is varied using the same constituent materials as in Example 4.
Example 6 is an example in which the type of short fiber is changed.
Example 7 is an example in which the cog height is increased with the same constituent material as in Example 1.

In the manufacturing steps according to Examples 1 to 7 and the manufacturing steps according to Comparative Examples 1 to 4, the steps were performed under the same conditions except for the step of forming the cogs 1a. When vulcanizing the unvulcanized sleeve, in Examples 1 to 7 and Comparative Examples 1 to 4, the mold was placed on the vulcanization can with the vulcanization jacket placed outside the unvulcanized sleeve, and the temperature was 160 Vulcanization was carried out at 20 ° C. for 20 minutes. The sizes of the V-belt with cogs according to Examples 1 to 7 and Comparative Examples 1 to 4 are as follows. The outer peripheral length is 800 mm, the upper width is 20.0 mm, the belt thickness is 9.5 mm, and the cog height is the values shown in Tables 1 and 2. did.

In Examples 1 to 7, in the cog forming step S4, a method using the water jet processing machine exemplified in the above embodiment was adopted.
-Equipment used (water jet processing machine): MACH3B Model 1313 manufactured by Flow Japan Co., Ltd.
-Diameter of pin hole and reference hole: Diameter 10mm
・ Processing conditions: Belt thickness 20mm, processing speed 240mm / min

In Examples 1 to 7 and Comparative Examples 1 to 4, the unvulcanized rubber sheet for the compressed rubber layer and the unvulcanized rubber sheet for the stretch rubber layer were blended with the materials shown in Table 3 (Formulation 1 to 6). Each was kneaded with a Banbury mixer or the like, and the produced kneaded rubber was rolled through a calender roll to prepare. In Examples 1 to 7 and Comparative Examples 1 to 4, the unvulcanized rubber sheet for the first adhesive rubber layer and the unvulcanized rubber sheet for the second adhesive rubber layer were blended with the materials shown in Table 4, respectively. Rubber kneading was performed with a Banbury mixer or the like, and the produced kneaded rubber was rolled through a calender roll to prepare.

Details of the materials shown in Tables 3 and 4 are as follows.
Short fiber Aramid short fiber (a): Teijin Cornex short fiber, average fiber length 3 mm, average fiber diameter 14 μm
・ Aramid short fiber (b): Teijin Cornex short fiber, average fiber length 6 mm, average fiber diameter 14 μm
Aramid short fiber (c): Teijin Cornex short fiber, average fiber length 3 mm, average fiber diameter 20 μm
Aramid short fiber (d): Teijin Cornex short fiber, average fiber length 2 mm, average fiber diameter 14 μm
Polyamide 66 short fiber: Nylon 66 fiber manufactured by Toray, average fiber length: 6 mm, average fiber diameter: 30 μm
・ Naphthenic oil: “RS700” manufactured by DIC Corporation
・ Carbon black: “Seast 3” manufactured by Tokai Carbon Co., Ltd.
Anti-aging agent: “Nonflex OD3” manufactured by Seiko Chemical Co., Ltd.
・ Vulcanization accelerator: Tetramethylthiuram disulfide (TMTD)
・ Silica: “Nippil VN3” manufactured by Tosoh Silica Corporation

In Examples 1 to 7 and Comparative Examples 1 to 4, the core wire 4a is made of 1000 denier polyethylene terephthalate (PET) fibers in a 2 × 3 twist configuration with an upper twist factor of 3.0 and a lower twist factor of 3.0. A cord having a total denier of 6,000 twisted and subjected to an adhesion treatment was used.

In Examples 1 to 7 and Comparative Examples 1 to 4, as the reinforcing cloth 2, a plain woven canvas using cotton spun yarn was dipped in an RFL solution, and the canvas was further heat-treated at 150 ° C. for 2 minutes. A canvas with rubber formed by friction processing in which the rubber composition shown in Table 4 was rubbed was used.

In the actual vehicle U / D endurance test, the V-belts with cogs according to Examples 1 to 7 and Comparative Examples 1 to 4 are attached to a belt type continuously variable transmission of an actual vehicle (scooter), and the chassis dynamo tester Traveling with the pattern shown in No. 4 (that is, UP / DOWN driving in which the throttle is fully opened (90 seconds for 90 km / h for 90 seconds) and the throttle is fully closed (30 seconds for idling) from the idling state) was performed up to a traveling distance of 10,000 km. .

In the actual vehicle U / D durability running test, the state of the side surface of the cogged V-belt according to Examples 1 to 7 and Comparative Examples 1 to 4 was observed. Specifically, the orientation disorder of the short fiber due to the flow of rubber in the compressed rubber layer affects, (1) cracks due to delamination in the compressed rubber layer (cog part cracks), and (2) due to insufficient lateral pressure resistance. The presence / absence (and extent) of interface peeling (under-core peeling) under the core line resulting from lateral pressure deformation was observed. The observation results according to Examples 1 to 7 and Comparative Examples 1 to 4 are shown in Tables 1 and 2.

In Comparative Example 1, since the compressed rubber layer was flowed by conventional molding to form a plurality of cogs, the rubber flowed in the compressed rubber layer, resulting in cog cracks and peeling under the cord. More specifically, as shown in FIG. 5 (a), a dent 5x is formed on the belt outer peripheral side 1y of the cog portion in the compressed rubber layer 5, and the adhesive rubber layer 4 enters the dent 5x. The adhesive rubber layer 4 was peeled off from 4a (peeling under the core line). Further, a crack 5y1 starting from the dent 5x occurred at the interface between the compressed rubber layer 5 and the adhesive rubber layer 4. In the compressed rubber layer 5, the flow shape clearly appeared, cracks 5y2 and 5y3 (cog cracks) were generated between the plurality of sheet members, and separation between the plurality of sheet members occurred.

Comparative Example 2 is an example in which the cog height is increased as compared to Comparative Example 1. However, because the cog height is large, the flow of rubber in the compressed rubber layer also increases, and the orientation disorder of the short fibers also increases. Cog part cracks and peeling below the core line also occurred.

Comparative Example 3 is an example in which the cog height is made smaller than that of Comparative Example 1, but because the cog height is small, the flow of rubber in the compressed rubber layer is also reduced, and the orientation disorder of the short fibers is also reduced. Although peeling under the cord did not occur, some cracks in the cog part occurred.

Comparative Example 4 is an example in which the blending amount of the short fibers is reduced with respect to Comparative Example 1, but the cog cracks are generated to the same extent as Comparative Example 1, and the side pressure resistance is insufficient. Was further generated.

On the other hand, when the state of the side surface of the cogged V-belt according to Examples 1 to 7 after the test was observed, no cog cracks or peeling under the cord occurred.

The preferred embodiments and examples of the present invention have been described above. However, the present invention is not limited to the above-described embodiments, and various design changes can be made as long as they are described in the claims. is there.

A plurality of cogs may be provided not only on the belt inner peripheral side but also on the belt outer peripheral side.
The reinforcing cloth may be provided on the inner peripheral side of the belt, or may not be provided on either the inner peripheral side of the belt or the outer peripheral side of the belt. Further, the reinforcing cloth may be buried in the compressed rubber layer or the stretched rubber layer. In the case where a reinforcing cloth is provided on the inner peripheral side of the belt, the reinforcing cloth may be bonded to the surface of the compressed rubber layer by a known method after the cog forming step.
The short fiber may not be included in the unvulcanized rubber sheet for the stretch rubber layer. Further, the short fiber may not be contained in any of the unvulcanized rubber sheet for the compressed rubber layer and the unvulcanized rubber sheet for the stretch rubber layer.
The unvulcanized rubber sheet for the compressed rubber layer is not limited to being composed of a plurality of sheet members, and may be composed of a single sheet member.
-The core wire may be simply brought into contact with the adhesive rubber layer without being embedded in the adhesive rubber layer (for example, in the unvulcanized sleeve forming process, the core wire is bonded to the unvulcanized rubber sheet for the adhesive rubber layer and the stretched rubber layer. Or between the unvulcanized rubber sheet for the adhesive rubber layer and the unvulcanized rubber sheet for the compression rubber layer). Further, the adhesive rubber layer may be omitted.
-The cross section orthogonal to the belt longitudinal direction in the cogged V-belt is not limited to the inverted trapezoidal shape. For example, the side surface of the stretched rubber layer may be parallel to the belt thickness direction, or may be inclined in a direction in which the belt width becomes narrower toward the belt outer peripheral side.

This application is based on Japanese Patent Application No. 2016-167011 filed on Aug. 29, 2016, and Japanese Patent Application No. 2017-158621 filed on Aug. 21, 2017, the contents of which are incorporated herein by reference.

1 Vog with Cog 1a Cog 1x Belt inner circumference 1y Belt outer circumference 3 Stretch rubber layer 4a Core wire 5 Compression rubber layer 5x Recess 5y1-5y3 Crack

Claims

In the manufacturing method of the cogged V-belt in which a plurality of cogs extending in the belt width direction and spaced apart from each other in the belt longitudinal direction are provided on the belt inner peripheral side,
A plurality of unvulcanized rubber sheets for a compressed rubber layer to be a compressed rubber layer disposed on the inner circumferential side of the belt and at least a non-vulcanized rubber sheet for an elongated rubber layer to be an elongated rubber layer disposed on the outer circumferential side of the belt An unvulcanized sleeve forming step of laminating unvulcanized rubber sheets to form an unvulcanized sleeve;
After the unvulcanized sleeve forming step, a vulcanized sleeve forming step of vulcanizing the unvulcanized sleeve to form a vulcanized sleeve;
A cog forming step of forming the plurality of cogs in the compressed rubber layer after the vulcanization sleeve forming step;
A method for producing a cogged V-belt, comprising:
2. The cogged V according to claim 1, wherein the unvulcanized rubber sheet for the compressed rubber layer laminated in the unvulcanized sleeve forming step includes short fibers oriented in the belt width direction. A method for manufacturing a belt.
3. The cog according to claim 2, wherein in the unvulcanized sleeve forming step, a plurality of sheet members each including the short fibers and laminated with each other are used as the unvulcanized rubber sheet for the compression rubber layer. A manufacturing method of a V-belt.
In the unvulcanized sleeve forming step, an unvulcanized rubber sheet for an adhesive rubber layer serving as an adhesive rubber layer is provided between the unvulcanized rubber sheet for the compressed rubber layer and the unvulcanized rubber sheet for the stretch rubber layer. The method for producing a cogged V-belt according to any one of claims 1 to 3, wherein the cogged V-belt is arranged.
5. The cogging according to claim 4, wherein in the unvulcanized sleeve forming step, a core wire extending in a longitudinal direction of the belt is disposed in the unvulcanized rubber sheet for the adhesive rubber layer. V belt manufacturing method.