JP2004108576A - Toothed belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a belt preventing crack and damage of a belt back surface occurring under a high loaded condition, wear and damage of belt end surface due to movement of the belt to a pulley flange part and maintaining regular operation of an engine by reducing friction coefficient of material used for a tooth part of a toothed belt. <P>SOLUTION: This invention relates to the toothed belt formed by providing a plurality of tooth parts 32 along a longitudinal direction of the toothed belt 5 having core wire 1 embedded in a back part 2, and covering a surface of the tooth part 3 with tooth cloth 4. Dynamic friction coefficient of the tooth cloth 4 used for the tooth part 2 is kept less than 0.2. As the method for that, tooth cloth which consists of polytetrafluorethylene fiber and nylon fiber is used for fiber material constructing the tooth part. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to, for example, a camshaft of an automobile engine or a camshaft and a drive of an injection pump, a toothed belt coated with a cloth used for synchronous transmission of a general industrial machine, etc. The present invention relates to a toothed belt which maintains wear resistance and tooth chipping resistance, in particular, prevents damage to the belt end face, and reduces elongation of a core wire to reduce jumping to enhance transmission capacity.

Toothed belts that drive camshafts, injection pumps, oil pumps, water pumps, etc. of automotive engines increase the load on the belts due to the increase in engine output and the rise in ambient temperature due to the compact engine room. Since the use environment of the toothed belt has become particularly severe in recent years, further improvement in durability is required. Also, with regard to toothed belts used for general industry, it is required to extend a replacement cycle for driving a high load of an injection molding machine or the like.

The failure modes of toothed belts are roughly classified into belt breaks due to bending fatigue of core wires and cracks caused by insufficient heat resistance of rubber, overload, insufficient heat resistance of tooth cloth and tooth rubber, and chipping due to wear of tooth cloth. Is done. With respect to belt bending due to core bending fatigue and insufficient heat resistance of rubber, improvements such as reduction in core material, core configuration, and heat resistance of core treatment agents have been implemented. Also, with respect to the improvement of the heat resistance of rubber, failures have been reduced due to the use of hydrogenated nitrile rubber and the like.

A transmission belt using carbon fiber instead of glass fiber or aramid fiber as the core wire has also been proposed. For example, in Patent Document 1, a carbon fiber cord is used as a core wire in a urethane elastomer belt material, and in Patent Document 2, a belt body is formed with a thermoplastic elastomer belt material before being twisted with a single twist carbon material. What improved the adhesion by processing with the thermoplastic elastomer of the same material is used. Patent Document 2 discloses that the twist ratio is 2.0 to 4.0, the twist ratio is 1/2 to 3/2 of the twist ratio, the initial strength is large, the elongation is small, and the water resistance is low. A toothed belt having improved durability and bending fatigue resistance is disclosed.

However, in the case of a conventional toothed belt, in the case of high-load transmission, belt jumping occurs due to elongation of the core wire, and the residual strength of the belt after traveling may be significantly reduced as compared with before the traveling.
Japanese Patent No. 2954554 JP-A-10-2379 Japanese Patent Publication No. 03-4782

In particular, a toothed belt that drives an engine or an industrial drive device in which a high load is applied to the belt has a high load, and the pulley shaft is bent due to the high load. Cutting and tooth chipping due to abnormal wear and side damage are likely to occur.

ベ ル ト Also, the belt stretches due to the high load, the auto tensioner does not operate, the proper load is not applied to the belt, and a phenomenon that hinders the normal operation of the engine occurs.

For the side surface wear, damage, and belt elongation of the belt, the fabric material of the toothed belt that meshes with the pulley teeth is treated with fluororesin or layered graphite that has the effect of reducing the coefficient of friction. However, sufficient improvement measures have not been found yet.

The present invention solves the above problems by lowering the coefficient of friction of rubber used for the back of a toothed belt, thereby causing cracks, damage, and movement of the belt to a pulley flange portion of the belt rear surface generated under high load. The present invention can provide a belt that can prevent the end face of the belt from being worn and damaged by the above, thereby maintaining the normal operation of the engine.

As means thereof, the present invention has a plurality of rubber-based tooth portions disposed at predetermined intervals along the longitudinal direction, and a rubber-based back portion having a core wire embedded therein, and the surface of the tooth portion is provided. In a toothed belt coated with a tooth cloth, at least the structure of the woven fabric used for the tooth portion is a toothed belt made of polytetrafluoroethylene.

According to a second aspect of the present invention, the woof of the tooth cloth constituting the tooth portion has a polyurethane elastic yarn as a core, and a woven fabric in which polytetrafluoroethylene fibers and nylon fibers are mixed and twisted are arranged around. 1. The toothed belt according to item 1.

According to a third aspect of the present invention, the weft of the tooth cloth constituting the tooth portion has a polyurethane elastic yarn as a core and a polytetrafluoroethylene fiber disposed around the polyurethane yarn and a polyurethane elastic yarn as a core and nylon fibers disposed around the periphery. The toothed belt according to claim 1, wherein the wefts are alternately arranged.

<4> The toothed belt according to any one of <1> to <3>, wherein the woven fabric constituting the teeth is treated with resorcin-formalin-latex.

The invention according to claim 5 is the toothed belt according to any one of claims 1 to 4, wherein the resorcin-formalin-latex contains 1 to 80 parts by mass of a fluororesin per 100 parts by mass of the latex. .

The invention according to claim 6 is the method according to any one of claims 1 to 5, wherein the woven fabric constituting the tooth portion is treated with a rubber paste containing 10 to 200 parts by mass of graphite with respect to 100 parts by mass of rubber. In the toothed belt.

The invention according to claim 7 is the toothed belt according to any one of claims 1 to 6, wherein 1 to 20 parts by mass of short fibers are blended in at least the rubber layer on the back.

The invention according to claim 8 is the toothed tooth according to any one of claims 1 to 7, wherein the rubber is a mixture of a hydrogenated nitrile rubber and a metal salt of an unsaturated carboxylic acid and an organic peroxide or a sulfur compound. On the belt.

The invention according to claim 9 is the toothed belt according to any one of claims 1 to 6, wherein the rubber is obtained by adding 15 to 40 parts by mass of a metal salt of unsaturated carboxylic acid to hydrogenated nitrile rubber based on the total polymer. It is in.

The invention according to claim 10 is the toothed belt according to claim 7, wherein the rubber is obtained by adding 5 to 15 parts by mass of a metal salt of an unsaturated carboxylic acid to a hydrogenated nitrile rubber based on the total polymer.

The invention according to claim 11 is the toothed belt according to any one of claims 1 to 10, wherein the back hardness of the toothed belt is 80 degrees or more (JISA hardness meter) or more.

According to a twelfth aspect of the present invention, after the core wire of the toothed belt is impregnated and attached to a multifilament yarn of carbon fiber having a total denier of 1,000 to 10,000 with a processing liquid comprising rubber latex and epoxy resin. This is a cord in which this is twisted at a rate of 5 to 10 times / 10 cm and the surface thereof is coated with an adhesive layer, the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%, and the tensile elasticity of the belt. rate is in the belt according to any one of claims 1 to 11 is 50~85N / mm ^2.

According to a thirteenth aspect of the present invention, after the core wire of the toothed belt is impregnated and attached to a multifilament yarn of carbon fiber having a total denier of 1,000 to 10,000 with a treatment liquid comprising rubber latex and epoxy resin. This is a cord in which the fiber is twisted 5 to 10 times / 10 cm, and further twisted 2.5 to 5 times / 10 cm, and the surface thereof is coated with an adhesive layer. ratio is 70% to 90%, and tensile modulus of the belt is in the toothed belt according to any one of claims 1 to 11 is 50~85N / mm ^2.

The invention according to claim 14 is the toothed belt according to claim 12 or 13, wherein the adhesive layer is a single layer obtained from a resorcin-formaldehyde-latex liquid.

The invention according to claim 15 is the toothed belt according to claim 12 or 13, wherein the adhesive layer comprises two layers, a lower layer made of a resorcin-formaldehyde-latex liquid and an upper layer made of a rubber paste.

The toothed belt of the present invention has a plurality of rubber-based base portions arranged at predetermined intervals along the longitudinal direction, and a back portion based on a rubber base material having a core wire embedded therein. In the toothed belt whose surface is covered with a tooth cloth, at least the woven fabric used for the tooth portion is a toothed belt made of polytetrafluoroethylene fiber and nylon fiber, so that the woven fabric has a friction coefficient of 0.1. 2, which has the effect of preventing cracks and damage on the back surface of the belt, which occur under a high load, and wear and damage of the end face of the belt due to movement of the belt to the pulley flange.

According to the invention as set forth in claim 2, the woof of the tooth cloth constituting the tooth portion has a polyurethane elastic yarn as a core, and a woven fabric in which polytetrafluoroethylene fibers and nylon fibers are mixed and twisted are arranged around. Since the toothed belt according to claim 1 is provided with polyurethane elastic yarn, it is possible to easily improve the dimensional accuracy of the toothed belt during mass production and to reliably function as a toothed belt for automobiles. Can be exhibited.

According to the invention as set forth in claim 3, the weft of the tooth cloth constituting the tooth portion has a polyurethane elastic yarn as a core and a polytetrafluoroethylene fiber disposed around and a polyurethane elastic yarn as a core and nylon fibers as a core. The toothed belt according to claim 1, wherein the arranged weft yarns are alternately arranged, so that the dimensional accuracy of the toothed belt can be easily formed and a dimension usable as a toothed belt for an automobile is developed. There is an effect that it can be done.

According to the invention as set forth in claim 4, the toothed belt according to any one of claims 1 to 3, wherein resorcinol-formalin-latex treatment is applied to a woven fabric constituting the tooth portion. Even with fibers, there is an effect that the adhesiveness to the rubber of the teeth is excellent.

The invention described in claim 5 has an effect of improving the adhesion between the fluororesin and the fluorine fibers by dispersing the fluororesin in resorcin-formalin-latex, thereby improving the adhesiveness.

The invention described in claim 6 has the effect of preventing cracks and damage on the back surface of the belt generated under high load by dispersing graphite in the woven fabric, and preventing wear and damage of the belt end surface due to movement of the belt to the pulley flange portion. is there.

According to the invention of claim 7, when the compounding amount of the short fiber is less than 1 part by mass with respect to 100 parts by mass of rubber, the effect of compounding the short fiber is small, and when the compounding amount exceeds 20 parts by mass. In addition, the Mooney viscosity of the rubber becomes too high, which causes a problem in a processing step (dispersion failure in the kneading step, inability to roll in the sheet rolling step, poor surface texture and no thickness). In addition, there is a problem that teeth are not formed with high accuracy.

According to the invention as set forth in claim 8, since the rubber is obtained by mixing a metal salt of unsaturated carboxylic acid and an organic peroxide or a sulfur compound with the hydrogenated nitrile rubber, the coefficient of dynamic friction of the rubber used for the back portion is set to 0.1. There is an effect that can be made smaller than 5.

According to the ninth aspect of the present invention, the rubber according to any one of the first to sixth aspects, wherein the rubber is obtained by adding 15 to 40 parts by mass of an unsaturated metal carboxylate to a hydrogenated nitrile rubber based on the total polymer. Since the belt is used, cracks and damages on the back surface of the belt, which occur under a high load, and wear and damage of the end face of the belt due to movement of the belt to the pulley flange portion can be prevented.

According to the tenth aspect of the present invention, the rubber is the toothed belt according to the seventh aspect, wherein the unsaturated carboxylic acid metal salt is added to the hydrogenated nitrile rubber in an amount of 5 to 15 parts by mass based on the total polymer. The coefficient of kinetic friction of the rubber used for the back portion can be made smaller than 0.5 as in the case of the invention described in claim 8, and cracks and damages on the back surface of the belt, which occur under high load, and damage to the pulley flange portion of the belt. End face wear and damage due to movement can be prevented.

According to the eleventh aspect of the present invention, since the back surface hardness of the toothed belt is equal to or greater than 80 degrees (JISA hardness meter), stress is reduced. Even if it is added, deformation of the rubber can be suppressed. For this reason, heat generation during belt running can be suppressed, and resistance during friction can be reduced.

According to the invention as set forth in claims 12 to 15, the core wire of the toothed belt is impregnated and attached to a multifilament yarn of carbon fiber having a total denier of 1,000 to 10,000 with a processing liquid composed of rubber latex and epoxy resin. After this, the cord is twisted 5 to 10 times / 10 cm and the surface thereof is coated with an adhesive layer, and the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%. The toothed belt driving device according to any one of claims 1 to 11, which has a tensile elasticity of 50 to 85 N / mm ² , so that the elongation of the cord is reduced, the jumping is reduced, and the transmission capacity is reduced. And the durability in running under high temperature, high tension and high temperature and high humidity can be improved.

Hereinafter, the best mode for carrying out the present invention will be described.
FIG. 1 is an overall perspective schematic view of a toothed belt according to an embodiment of the present invention. In FIG. 1, a toothed belt 5 includes a plurality of tooth portions 3 arranged at predetermined intervals along a longitudinal direction, a back portion 2 continuous with the tooth portions 3, a core wire 1 embedded in the back portion 2, and a tooth portion. 3 is a structure having a tooth cloth 4 coated on the surface. The back portion 2 and the tooth portion 3 constitute a belt body formed of the rubber layer 9. Further, the tooth cloth 4 is configured using a fiber material formed by weaving a weft 7 extending in the longitudinal direction of the belt and a warp 8 extending in the width direction of the belt.

Here, it is preferable that at least the friction coefficient of the woven fabric used for the tooth portion is smaller than 0.2.
When a belt having a coefficient of kinetic friction of more than 0.2 is used, the thrust force is increased, and the belt is moved in front of the shaft, thereby causing damage to the belt end face and causing problems such as breakage of the belt.
The structure of the woven fabric used here is a 66-nylon fiber (400 denier) as a warp, and a poly-tetrafluoroethylene fiber (400 denier) and a nylon fiber (250 tex) mixed around a urethane elastic yarn (70 denier) as a core. The woven fabric which was arranged around was used.

Further, as another configuration of the tooth cloth, the weft is made of polyurethane elastic yarn (100 tex) as a core and the weft and polyurethane elastic yarn (100 tex) arranged around polytetrafluoroethylene fiber (1400 tex) and nylon as a core. A tooth cloth was used in which fibers (250 tex) were alternately arranged with weft yarns arranged around the fibers.

Examples of the material of the polytetrafluoroethylene fiber include PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene, hexafluoropropylene copolymer), and ETFE (tetrafluoroethylene, olefin copolymer). Although there is no problem even if this material is used, fiberization was performed from PTFE (polytetrafluoroethylene).

ベ ル ト The belt back surface hardness is at least 80 degrees or more, preferably 85 degrees or more (JISA). In order to make the back surface hardness at least 80 degrees or more, as a rubber compound, H-NBR is used, or an unsaturated carboxylic acid metal salt is added to H-NBR in an amount of 15 to 40 parts by mass relative to the total polymer, or Add 5 to 15 parts by mass. When the amount of the unsaturated carboxylic acid metal salt is less than 5 parts by mass, the rubber hardness does not reach the predetermined hardness. On the other hand, when it exceeds 40 parts by mass, the rubber hardness becomes too large, the belt rigidity becomes high, and the bending fatigue property is reduced. Inferior belt life is shortened.

The hydrogenated nitrile rubber needs to have a hydrogenation rate of at least 90% or more from the viewpoint of heat resistance, and preferably 92 to 98%. In order to ensure a modulus (tensile modulus) and elongation at break, as well as a high tear strength and hardness, by blending a metal salt of an unsaturated carboxylic acid with the hydrogenated nitrile rubber, hydrogenated nitrile is used as described above. It is desirable to mix 15 to 40 parts by mass of the unsaturated carboxylic acid metal salt in the rubber with respect to the total polymer, or 1 to 20 parts by mass of the short fiber with respect to the polymer component 100 when 5 to 15 parts by mass is mixed. It is necessary to do.

As the core wire 3, a filament of E glass or high-strength glass of 5 to 9 μm or a filament of a para-aramid fiber of 0.5 to 2.5 denier is twisted, RFL solution, epoxy solution, isocyanate solution and rubber Twisted cords treated with an adhesive with the compound are used.

Further, it is preferable to use carbon fiber as the core wire 3. The core wire 3 is made by impregnating and adhering a multifilament yarn of carbon fiber having a total denier number of 1,000 to 10,000 with a treatment liquid comprising a rubber latex and an epoxy resin, and then twisting it one by one at 5 to 10 times / 10 cm. Alternatively, a twisted cord may be twisted at 5 to 10 times / 10 cm and further twisted at 2.5 to 5 times / 10 cm.

The monofilament (single fiber) that constitutes the multifilament yarn of carbon fiber has a cross-sectional shape that is substantially close to a perfect circle, and efficiently assembles a large number of filaments to reduce the space between closely-connected filaments. This increases the strength of the cord. Specifically, the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%, the filament group is efficiently and highly filled, and the tensile modulus of the belt is 50 to 85 N / mm ² . If it is elliptical, the cords are more likely to break than the monofilaments rub against each other. Further, if the shape is other than this, even if the filaments are assembled, the space between the filaments that are close to each other increases, and the strength of the cord cannot be improved.

処理 The content of the treatment liquid (solid content) in the cord is 10 to 40 parts by mass, preferably 15 to 35 parts by mass, per 100 parts by mass of the multifilament yarn of carbon fiber. When the amount is less than 10 parts by mass, the fatigue resistance of the cord may be reduced due to the rubbing between the monofilaments. On the other hand, when the amount exceeds 40 parts by mass, the heat resistance, water resistance and solvent resistance of the cord may be decreased. .

含有 The content of the rubber latex (solid content) contained in the treatment liquid (solid content) is 20 to 80 parts by mass, preferably 30 to 70 parts by mass based on 100 parts by mass of the treatment liquid (solids). When the amount is less than 20 parts by mass, the flexibility of the cord is reduced, and the bending fatigue resistance of the belt may be reduced. On the other hand, when the amount is more than 80 parts by mass, the adhesiveness of the cord becomes excessive, and the handleability is deteriorated. .

Specific examples of the rubber latex include acrylonitrile-butadiene rubber latex, chloroprene rubber latex, styrene-butadiene rubber latex, hydrogenated nitrile rubber latex (H-NBR latex), styrene-butadiene-vinylpyridine terpolymer (VP) Latex), one or more blends of EPDM rubber latex.

(4) The content of the epoxy resin in the treatment liquid contained in the treatment liquid (solid content) is 20 to 80 parts by mass, preferably 30 to 70 parts by mass, based on 100 parts by mass of the treatment liquid (solids). If the amount is less than 20 parts by mass, the adhesiveness between the cord and the rubber interface may decrease. If the amount exceeds 80 parts by mass, the flexibility of the cord may decrease, and the bending fatigue resistance of the belt may decrease.

具体 Specific examples of the epoxy resin include one or more of ethylene glycol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, sorbitol polyglycidyl ether, and hexanediol diglycidyl ether.

The above-mentioned cord has an adhesive layer adhered to its surface. Here, the adhesive layer may be a single layer obtained from a resorcin-formaldehyde-latex liquid (RFL liquid) or obtained from a rubber paste. It may be a single layer, or two layers, a lower layer made of RFL liquid and an upper layer made of rubber paste.

The RFL solution is a mixture of an initial condensate of resorcinol and formaldehyde and a rubber latex. In this case, the molar ratio of resorcinol to formaldehyde is preferably 3/1 to 1/3 in order to enhance the adhesive strength. is there. The initial condensate of resorcinol and formaldehyde is mixed with rubber latex so that the resin content is 5 to 50 parts by mass with respect to 100 parts by mass of rubber of rubber latex, and resorcinol and formaldehyde containing phenolic resin are further mixed. The mass ratio of the solid content of the precondensate and the rubber latex is adjusted to 5/95 to 40/60. If it is less than 5/95, the adhesiveness is significantly reduced, and if it is more than 40/60, the rubber latex content is reduced, heat resistance is deteriorated, and bending fatigue resistance is reduced.

As the rubber latex used in the RFL treatment liquid, one or two of hydrogenated nitrile rubber latex (H-NBR latex), styrene-butadiene-vinylpyridine terpolymer (VP latex), chloroprene rubber latex, and EPDM rubber latex are used. More than one blend is used. The hydrogenated nitrile rubber latex and the vinyl pyridine rubber latex are mixed at a solid content mass ratio of 60/40 to 95/5. If the mass ratio of the hydrogenated nitrile rubber is less than 60, the heat resistance is deteriorated and the bending fatigue resistance is reduced, and if it exceeds 95, the water resistance is significantly reduced.

炭素 The carbon fiber cord used is treated by the following method. First, the untreated untwisted multifilament yarn is impregnated with a treatment liquid comprising a rubber latex and an epoxy resin, and then heat-treated through an oven adjusted to 130 to 250 ° C. Subsequently, the above-treated multifilament yarn is single-twisted at 5 to 10 times / 10 cm, or twisted at 5 to 10 times / 10 cm, and further twisted at 2.5 to 5 times / 10 cm. After that, the cord is impregnated with an RFL solution to form an adhesive layer.

Further, the treatment cord is immersed in rubber glue to adhere a rubber layer, and then heat-treated through an oven adjusted to about 130 to 180 ° C.
Examples of the rubber paste include hydrogenated nitrile rubber (H-NBR), chloroprene rubber (CR), chlorosulfonated polyethylene rubber (CSM), NBR, ethylene propylene diene monomer (EPDM), and ethylene propylene copolymer (EPR). ), SBR, a rubber compound of isoprene rubber (IR) and natural rubber (NR), which is obtained by dissolving in a solvent such as aromatic hydrocarbon such as toluene and xylene.

Alternatively, the treatment code may be impregnated with an RFL solution as described above to form a lower layer, and then overcoated with a rubber paste to form two upper layers.

Next, the present invention will be described specifically with reference to examples. As Example 1, rubber having the composition shown in Table 1 was kneaded by a usual method, and rubber sheets A-1 to A-2 having a predetermined thickness were adjusted using a calender roll. Further, the tooth cloth was subjected to the processing shown in Table 3 using the fibers shown in Table 2. In the RFL treatment in Table 3, the tooth cloth was immersed in an RFL treatment solution having the composition of C-1 shown in Table 3, dried at 120 ° C, and then heat-treated at 180 ° C for 2 minutes. The rubber paste treatment in Table 3 is performed by dissolving the rubber compound shown in Table 4 in MEK and toluene as shown in Table 3 in C-2 and C-3, and then polyal polyisocyanate (trade name) as an isocyanate compound. PAPI) is added to the treatment liquid, and MBI or N- (1,3-Dimethyl-Butyl) -N'-phenyl-phenylenediamine, a fluororesin powder, or a friction reducing material such as graphite is added to the treatment liquid. The cloth was immersed and dried.

摩擦 Furthermore, the coefficient of friction was measured before the woven fabric was subjected to the RFL treatment and the rubber paste treatment, and was found to be 0.2. The mating material used was a table having a center line average roughness (Ra) specified in JIS KB0601 of 0.4 μm Ra or less and a material of an S45C iron plate. The measurement was carried out by the method A of JIS K7125K “Testing method of friction coefficient of plastic film and sheet” and JIS K7218 “Testing method of sliding wear of plastic”. The woven fabric used at this time was polytetrafluoroethylene fiber, TOYOFLON manufactured by Toray Fine Chemical Co., Ltd., and urethane elastic yarn used was Spandex, manufactured by Fuji Boseki Co., Ltd. As nylon 6,6, Leona 66 manufactured by Asahi Kasei Corporation was used.

Next, the above-mentioned leaf cloth is wound around a mold having a ZBS tooth profile of 120 teeth for belt production, and a bonding process is performed using a rubber paste obtained by dissolving a pair of RFL and hydrogenated nitrile rubber in a SZ twist using a solvent such as toluene. The core wires shown in Table 5 were wound around the spiral at a pitch shown in Table 6 with a predetermined tension. The rubber sheet of Table 1 was stuck on this core wire. Further, the mixture is put into a vulcanization can and a tooth profile is formed by a normal press-fitting method. Then, the pressure is vulcanized at 165 ° C for 30 minutes, and the back surface of the belt is polished to a constant thickness and cut to a constant width (30 mm). Thus, a running toothed belt was obtained. Table 7 shows the adhesiveness between the tooth cloth and the rubber of the toothed belt. Regarding the adhesiveness between the tooth cloth and the rubber, if the adhesive force is 60 N / 25 mm width or more at the bottom of the tooth, the tooth cloth does not peel off from the toothed belt during actual running of the toothed belt, and the durability is sufficient. Having. Therefore, the reference value of the adhesive force is 60 N / 25 mm or more.

ベ ル ト The size of the produced belt has a belt width of 30 mm, a belt tooth shape ZBS, a number of teeth of 120, and a tooth pitch of 9.525 mm, and is usually indicated as 120 ZBS30. As the traveling test device, a test device having a layout including a crank pulley 11 having 22 teeth, a cam pulley 13 having 44 teeth, a water pump pulley 15 having 19 teeth, an eccentric pulley 19 and an idler 21 shown in FIG. 2 is used. A running test was performed at an effective tension of 3700 N applied to the belt at a rotation speed of the crank pulley of 4000 rpm and an initial tension of 350 N. Then, a mark (painted) was formed on the front surface of the tooth portion with white ink at both end tooth portions of the running test belt. The vehicle was run at 4000 rpm for 200 hours under running conditions, and the end face damage was evaluated based on the disappearance of the mark after running. Table 8 shows the relationship between the end face phenomenon and the evaluation points.

According to the results in Table 7, the examples have a high adhesive force between the tooth cloth and the rubber and sufficiently satisfy the reference value. In the examples in which the white mark remains at 85% or more according to the results in Table 8, the examples show It can be seen that the movement is small and no end face damage is caused.

Examples 4 to 6
Next, as Examples 4 to 6, a non-twisted multifilament yarn of carbon fiber (T700GC / 6K / 31E (model number, manufactured by Toray Industries, Inc.) with a fineness of 4,300 denier) was treated with a treatment liquid (fixed concentration 40 mass). % Of vinylpyridine-styrene-butadiene rubber latex: after passing through a treatment liquid tank containing 200 parts by mass of JSR and 200 parts by mass of ethylene glycol diglycidyl ether in 500 parts by mass of water) for impregnation. And heat-treated in an oven controlled at 140 ° C. Subsequently, the treated multifilament yarn was twisted 5 times / 10 cm to form a cord. The cord was immersed in an RFL solution shown in Table 9 and heat-treated at a temperature of 130 to 180 ° C. to form an adhesive layer. Formed.

関係 FIG. 2 shows the result of measuring the relationship between the number of twists and the strength of the treated cord by an autograph. According to this, it is understood that high strength can be maintained when the number of twists is 5 to 10 times / 10 cm in the single twist cord.

ゴ ム As a rubber sheet for the tooth portion and the back portion, rubber having the composition shown in Table 1 was kneaded by a usual method and adjusted to a predetermined thickness by a calender roll.

As the tooth cloth and the treatment therefor, the same cloth and material as those used in Example 1 were used.

Next, the above-mentioned tooth cloth is wound around a mold having 120 teeth of STPD tooth form for producing a belt, and a pair of carbon fiber cords (single twist number, 5 times / 10 cm) of a pair of SZ twists is used as a core wire at a pitch (1.0 mm / This was wound around the spiral with a predetermined tension. After winding the rubber sheet of Table 1 on the core wire, the jacket was covered and put into a vulcanizing can, and was vulcanized under pressure by a normal press-fitting method to form a tooth profile. Thereafter, the back surface of the belt was polished to a constant thickness and cut to a constant width (10.0 mm) to obtain a running toothed belt.

There are three types of belts produced: belt width 10.0 mm, belt tooth shape STPD, number of teeth 120, tooth pitch 5.00 mm type 1, belt width 19.0 mm, belt tooth shape STPD, number of teeth 105, tooth pitch 8. Type 2 having a width of 30.0 mm, a belt tooth shape STPD, 100 teeth, and a tooth pitch of 14.00 mm.

Comparative Examples 3 to 5
As a core wire, three untwisted glass fibers (E-glass) were immersed in an RFL treatment solution shown in Table 2, and then heat-treated at 200 to 280 ° C. A single twisted cord was prepared in the S and Z directions at a twist number of 8 times / cm. Eleven of them were aligned and twisted at 12 times / cm. Furthermore, this was immersed in rubber paste and heat-treated at 130 to 180 ° C. Then, A-1 rubber was used as the rubber, and B-1 canvas was used as the tooth cloth. In addition, the tooth cloth treatment was the same as that of Comparative Example 1. Then, three kinds of toothed belts were manufactured under the same manufacturing conditions.

There are three types of belts produced: belt width 10.0 mm, belt tooth shape STPD, number of teeth 120, tooth pitch 5.00 mm type 1, belt width 19.0 mm, belt tooth shape STPD, number of teeth 105, tooth pitch 8. Type 2 having a width of 30.0 mm, a belt tooth shape STPD, 100 teeth, and a tooth pitch of 14.00 mm.

Table 4 shows the results of calculating the cord diameter, cord cross-sectional area, fiber cross-sectional area occupation ratio in the cord cross-sectional area, and belt elastic modulus (per width) of the toothed belts according to Examples 4 to 6 and Comparative Examples 3 to 5. It is shown in FIG. The belt elasticity was measured by an autograph at room temperature at a room temperature in relation to the rate of change in the distance between the axes of the belt and the axial load.

According to this, it can be seen that the example has a smaller elongation due to a higher strength and a higher elastic modulus than the comparative example, and the dimensional change at the time of high tension of the belt is smaller. Further, regarding the occupation ratio of the fiber cross-sectional area in the cord cross-sectional area, it can be seen that the carbon fiber cord of the example has a larger fiber filling amount than the glass fiber cord of the comparative example.

ジ ャ ン In addition, a jumping test was performed to compare the transmission capacity of the toothed belt. In this jumping test, the load on the driven shaft was increased while the belt was running, and the load value when jumping (tooth jump) occurred was measured. The test conditions were as follows. A toothed belt was suspended on a drive pulley having 22 teeth and a driven pulley having 20 teeth, and measurement was performed at a rotational speed of 3,600 rpm and an axial load of 10.6 kgf. The results are shown in Table 11.

According to this, it can be seen that the toothed belt of the example hardly causes jumping in the jumping test and has a high transmission capacity.

INDUSTRIAL APPLICABILITY The toothed belt of the present invention is used for a drive device for moving a driven robot arm by rotation of a drive side or a drive device for an overhead camshaft of an automobile. By setting the area ratio to 70 to 90% and filling a large amount of carbon fiber, the tensile elasticity of the belt is set to 50 to 85 N / mm ² , thereby reducing the elongation of the core wire and starting or stopping. , The overshoot on the driven side can be reduced, the responsiveness can be improved, and the transmission capacity can be increased.

1 is a schematic perspective view of a toothed belt according to the present invention. It is a schematic diagram of a running test device of a toothed belt. It is a graph which shows the relationship between the number of twists of the cord processing cord of the said toothed belt, and strength.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 1 core wire 2 back part 3 tooth part 4 tooth cloth 5 toothed belt 7 weft 8 warp 9 rubber layer 11 crank pulley 13 cam pulley 15 water pump pulley 19 eccentric pulley 21 idler 23 auto tensioner

Claims (15)

Teeth having a plurality of rubber-based teeth disposed at predetermined intervals along the longitudinal direction and a rubber-based back having embedded cords, and a tooth cloth coated on the surface of the teeth. A toothed belt, characterized in that at least the structure of the woven fabric used for said tooth portion is composed of polytetrafluoroethylene fibers and nylon fibers. 2. The toothed belt according to claim 1, wherein the weft yarn of the tooth cloth constituting the tooth portion has a polyurethane elastic yarn as a core, and a woven fabric in which polytetrafluoroethylene fibers and nylon fibers are mixed and twisted are disposed around. The weft of the tooth cloth constituting the tooth portion is obtained by alternately arranging a weft yarn having a polyurethane elastic yarn as a core and a polytetrafluoroethylene fiber disposed around and a weft yarn having a polyurethane elastic yarn as a core and nylon fibers disposed around. The toothed belt according to claim 1, wherein (4) The toothed belt according to any one of (1) to (3), wherein the fabric constituting the tooth portion is treated with resorcin-formalin-latex. The toothed belt according to any one of claims 1 to 4, wherein the resorcin-formalin-latex contains 1 to 80 parts by mass of a fluororesin per 100 parts by mass of the latex. The toothed belt according to any one of claims 1 to 5, wherein the woven fabric constituting the tooth portion is treated with rubber paste containing 10 to 200 parts by mass of graphite with respect to 100 parts by mass of rubber. (7) The toothed belt according to any one of (1) to (6), wherein 1 to 20 parts by mass of short fibers are blended in at least the rubber layer on the back. The toothed belt according to any one of claims 1 to 7, wherein the rubber is a mixture of a hydrogenated nitrile rubber and a metal salt of an unsaturated carboxylic acid and an organic peroxide or a sulfur compound. (7) The toothed belt according to any one of (1) to (6), wherein the rubber is obtained by adding 15 to 40 parts by mass of a metal salt of unsaturated carboxylic acid to hydrogenated nitrile rubber based on the total polymer. The toothed belt according to claim 7, wherein the rubber is obtained by adding 5 to 15 parts by mass of an unsaturated metal carboxylate to a hydrogenated nitrile rubber based on the total polymer. The toothed belt according to any one of claims 1 to 10, wherein the back hardness of the toothed belt is at least 80 degrees (JISA hardness meter). The core wire of the toothed belt is impregnated with a treatment liquid composed of a rubber latex and an epoxy resin on a multifilament yarn of carbon fiber having a total denier of 1,000 to 10,000, and then is impregnated 5 to 10 times / 10 cm. A cord whose surface is covered with an adhesive layer, and the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%, and the tensile modulus of the belt is 50 to 85 N / mm ² . The toothed belt according to any one of claims 1 to 11. The core wire of the toothed belt is impregnated and attached to a multifilament yarn of carbon fiber having a total denier of 1,000 to 10,000 with a treatment liquid comprising a rubber latex and an epoxy resin, and then is impregnated 5 to 10 times / 10 cm. It is a cord whose bottom is twisted and further twisted at a rate of 2.5 to 5 times / 10 cm, and the surface thereof is coated with an adhesive layer, and the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%, and belt according to any one of claims 1 to 11 tensile elastic modulus of the belt is 50~85N / mm ^2. 14. The toothed belt according to claim 12, wherein the adhesive layer is one layer obtained from a resorcin-formaldehyde-latex liquid. 14. The toothed belt according to claim 12, wherein the adhesive layer comprises two layers, a lower layer made of a resorcinol-formaldehyde-latex liquid and an upper layer made of a rubber paste.

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