JP4459574B2 - Toothed belt - Google Patents

Description

  The present invention relates to a tooth cloth used for, for example, driving a camshaft of an automobile engine or a camshaft and an injection pump, driving a rear wheel of a large motorcycle, or synchronous transmission of a general industrial machine. The present invention relates to a coated toothed belt. More particularly, the present invention relates to a toothed belt that prevents damage to the tooth cloth and teeth of the belt while maintaining wear resistance and tooth chipping resistance with respect to a high load belt.

  For toothed belts that drive camshafts, injection pumps, oil pumps, water pumps, etc. for automobile engines, as the output of the engine increases, the load on the belt increases and the ambient temperature increases as the engine room becomes more compact The usage environment of toothed belts has become particularly severe in recent years. For this reason, further improvement in durability is required. Further, in recent years, a drive system using a belt has been adopted for driving a rear wheel of a large-sized motorcycle in response to quietness and maintenance-free performance from the conventional chain or shaft drive. Furthermore, for toothed belts used for general industries, it is required to extend the replacement cycle, such as for high-load driving such as injection molding machines.

  The failure modes of toothed belts are broadly divided into belt cutting due to bending fatigue of the core wire and cracking due to insufficient heat resistance of rubber, overload, insufficient heat resistance of tooth cloth and tooth rubber, and tooth chipping due to wear of tooth cloth. Is done. For belt cutting due to bending fatigue of the core wire and insufficient heat resistance of the rubber, improvement of the core wire material, the diameter of the core wire configuration, etc., and improvement of heat resistance after the core wire treatment have been carried out. In addition, with respect to improving the heat resistance of rubber, failures have decreased due to the use of hydrogenated nitrile rubber.

  In particular, a toothed belt that drives an engine in which a high load is applied to the belt and a rear wheel drive or an industrial drive device for a two-wheeled vehicle has a high load, so the pulley shaft may be bent or the belt may be offset. Abnormal wear on the side surface of the belt due to friction with the pulley pulley and the like, cutting due to side surface damage, and tooth chipping are likely to occur.

  In addition, the belt is extended by a high load and the auto tensioner does not operate or the belt tension is lowered due to the biaxial drive, so that a proper load is not applied to the belt and a phenomenon that prevents the normal operation of the engine occurs.

  For this reason, a toothed belt is disclosed in which a fluororesin or a layered graphite having a friction coefficient reducing effect is added to a tooth cloth material on the surface of a toothed belt that meshes with pulley teeth against belt side wear, damage, and belt elongation. (For example, see Patent Documents 1 and 2).

  In addition, the tooth cloth is made of ultra high molecular weight polyethylene fiber for the purpose of reducing the friction coefficient of the tooth cloth surface, similar to the toothed belt to which the above-mentioned fluororesin having a friction coefficient reducing action or layered graphite is added. There is also a toothed belt using a twill canvas (see Patent Document 3).

  In addition, a transmission belt using carbon fibers instead of glass fibers and aramid fibers conventionally used as the core wire has been proposed. For example, a belt material made of urethane elastomer using a carbon fiber cord as a core wire (see, for example, Patent Document 4), or before a single twist is applied to the carbon material as a core wire, (For example, see Patent Document 5). Furthermore, when the upper twist coefficient is 2.0 to 4.0 and the lower twist coefficient is 1/2 to 3/2 of the upper twist coefficient, the initial strength is large, the elongation is small, and the water resistance is further improved. And a toothed belt with improved bending fatigue resistance has been proposed (see, for example, Patent Document 6).

JP 2002-221257 A JP 2001-304343 A Japanese Patent Publication No. 8-30514 Japanese Patent No. 2955454 Japanese Patent Laid-Open No. 10-2379 Japanese Patent Publication No. 3-4782

  However, in recent years, while the load on the toothed belt has increased, the market demands improved characteristics such as higher quietness and longer life. For this reason, the conventional toothed belt described above cannot sufficiently withstand such market demands.

  Specifically, in the case of adding a fluororesin or graphite having a friction coefficient reducing action, there is a problem that the friction coefficient increases as the tooth cloth is worn over a long period of use. Further, in the toothed belt using the twill woven canvas made of ultrahigh molecular weight polyethylene fiber as the tooth cloth described in Patent Document 3, the adhesive force between the tooth portion and the tooth cloth is not sufficient, and the temperature rise during use is also increased. Together, the adhesive force of the tooth cloth was reduced, and the tooth cloth and the tooth part could be damaged.

  Further, in the toothed belts described in Patent Documents 4 to 6, when a high load is transmitted, belt jumping (tooth skipping) occurs due to the extension of the core wire, and further, the remaining belt strength after traveling also travels. There were cases where it was greatly reduced compared to before.

  The present invention has been made in view of such a problem, and is used for driving a camshaft or a camshaft of an automobile engine with a high load acting thereon and an injection pump, and for driving a rear wheel of a large motorcycle. Or, while maintaining the wear resistance and chipping resistance of toothed belts used for synchronous transmission of general industrial machines, in particular, damage to the tooth cloth and teeth of the belt was prevented and the life was improved. An object is to provide a toothed belt.

A toothed belt according to a first aspect of the present invention for solving the above-mentioned problems is based on a plurality of rubber-based tooth portions arranged at predetermined intervals along the longitudinal direction and a rubber having a core wire embedded therein. A tooth cloth having a back portion and covering the surface of the tooth portion is a canvas formed by using a mixed yarn of nylon fiber or aramid fiber and ultrahigh molecular weight polyethylene fiber for either or both of weft and warp. In addition, a part of the ultrahigh molecular weight polyethylene fiber is melted to form an ultrahigh molecular weight polyethylene film on the tooth cloth surface.

  The ultra-high molecular weight polyethylene fiber mixed and twisted in the fiber melts during vulcanization and covers the tooth cloth surface. In addition, since ultra high molecular weight polyethylene fibers are mixed with nylon fibers or aramid fibers, ultra high molecular weight polyethylene fibers can be used even when high hardness hydrogenated nitrile rubber is used as the rubber forming the teeth. The tooth surface can be covered with a tooth cloth without impairing the characteristics of the.

  Further, the toothed belt of the second invention is the composite polymer according to the first invention, wherein the rubber is a mixture of hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt in a mass ratio of 40:60 to 50:50. The composite polymer body and hydrogenated nitrile rubber are blended in the body at a mass ratio of 90:10 to 20:80.

  Unsaturated carboxylic acid metal salt forms a polymer with a higher order structure, unsaturated carboxylic acid metal salt forms a finely dispersed filler in the polymer, and from the beginning, the unsaturated carboxylic acid metal salt is blended into the hydrogenated nitrile rubber. It will have a greater tensile strength.

  The toothed belt of the third invention is the toothed belt according to the first or second invention, wherein an adhesive layer is provided between the tooth cloth and the tooth part, and the adhesive layer is either hydrogenated nitrile rubber or urethane elastomer. It is something.

  The adhesive force between the tooth cloth and the tooth portion can be improved reliably, and the belt can be prevented from being damaged due to cracks and damage of the belt tooth surface that occurs under a high load.

  A toothed belt according to a fourth aspect of the present invention is the toothed belt according to any one of the first to third aspects, wherein the ultra high molecular weight polyethylene fiber has a molecular weight of 2 million to 5 million.

  The surface of the tooth cloth can be reliably coated with ultra high molecular weight polyethylene. Here, if the molecular weight of the ultrahigh molecular weight polyethylene is 2 million or less, the viscosity at the time of vulcanization will extremely decrease and flow down, and if it is 5 million or more, the resin film cannot be formed.

A toothed belt according to a fifth aspect of the invention is the toothed belt according to any one of the first to fourth aspects, wherein the core wire is a carbon fiber multifilament yarn having a total denier of 1,000 to 40,000 and a rubber latex. And a treatment liquid composed of an epoxy resin is impregnated and adhered, and then is twisted 5 to 10 times / 10 cm and coated with an adhesive layer on the surface thereof, and further the fiber cross-sectional area occupying the cross-sectional area of the cord The ratio is 70 to 90%, and the tensile elastic modulus of the belt is 50 to 85 N / mm ² .

The toothed belt according to a sixth aspect of the present invention is the toothed belt according to any one of the first to fourth aspects, wherein the core wire is a carbon fiber multifilament yarn having a total denier of 1,000 to 40,000 and a rubber latex and an epoxy. After impregnating and adhering a treatment solution made of resin, this is twisted 5-10 times / 10 cm, and further twisted 2.5-5 times / 10 cm, and the surface is coated with an adhesive layer. Furthermore, the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%, and the tensile elastic modulus of the belt is 50 to 85 N / mm ² .

  According to these fifth and sixth inventions, the extension of the core wire can be reduced, jumping can be reduced, and the load transmission capacity can be increased. Further, durability under high temperature and high tension and high temperature and high humidity can be improved.

  A toothed belt according to a seventh invention is the toothed belt according to the fifth or sixth invention, wherein the adhesive layer is a single layer obtained from a resorcin-formaldehyde-latex solution.

  The toothed belt according to an eighth aspect of the present invention is the toothed belt according to the fifth or sixth aspect, wherein the adhesive layer comprises two layers, a lower layer made of resorcin-formaldehyde-latex liquid and an upper layer made of rubber glue. is there.

  According to these seventh and eighth inventions, the adhesion of the carbon fibers is improved, the heat resistance is also improved, and the bending fatigue resistance of the toothed belt is improved.

  A toothed belt according to a ninth aspect of the present invention is the toothed belt according to any one of the first to eighth aspects, wherein the hardness of the back portion is 83 degrees or more with a JISA type hardness meter.

  Since the back hardness of the back portion is 83 degrees or more, preferably 87 degrees or more with a JISA-type hardness meter, deformation of rubber can be suppressed even when stress is applied. Further, since the hardness of the tooth portion is also increased, the deformation of the rubber is suppressed even when it is used reliably under a high load.

As described above, the toothed belt according to the present invention uses a canvas made of a mixed yarn of ultrahigh molecular weight polyethylene fibers in one or both of the warp and the weft. Since a film of high molecular weight polyethylene is formed, the friction coefficient of the surface can be greatly reduced, and the adhesive force between the tooth portion and the tooth cloth can be increased . For this reason, it is used for driving a camshaft or camshaft and injection pump of an automobile engine with high load, for driving a rear wheel of a large motorcycle, or for synchronous transmission of a general industrial machine. An effect is obtained that it is possible to prevent a defective tooth skipping phenomenon on the belt tooth portion generated in the toothed belt. Further, it is possible to prevent damage to the tooth part and the tooth cloth, such as chipped teeth, and to obtain the effect of extending the life of the toothed belt.

Further, the core wire of the toothed belt is impregnated with a treatment liquid composed of rubber latex and epoxy resin on a multifilament yarn of carbon fiber having a total denier of 1,000 to 40,000, and this is applied 5 to 10 times. A cord that is twisted at / 10 cm, or twisted at 5-10 times / 10 cm, then twisted at 2.5-5 times / 10 cm, and coated with an adhesive layer on the surface. Furthermore, since the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90% and the tensile elastic modulus of the belt is 50 to 85 N / mm ² , the extension of the core wire is reduced, and jumping is performed. The generation capacity of the load can be reduced and the load transmission capacity can be increased. And durability under high temperature high tension and high temperature and humidity can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a toothed belt according to an embodiment of the present invention.

  As shown in FIG. 1, the toothed belt 1 according to this embodiment includes a plurality of tooth portions 2 arranged at a predetermined pitch along the longitudinal direction of the belt, a back portion 4 in which a core wire 3 is embedded, And a tooth cloth 5 covering the surface of the tooth portion 2. The tooth cloth 5 is composed of a fiber material formed by weaving warp yarns 6 extending in the longitudinal direction of the belt and weft yarns 7 extending in the width direction of the belt.

  The rubber used as the base material constituting the tooth part 2 and the back part 4 is a compounded rubber obtained by blending an unsaturated carboxylic acid metal salt as a co-crosslinking agent with a hydrogenated nitrile rubber as a main component, and is crosslinked with an organic peroxide. It will be.

  The hydrogenated nitrile rubber needs to have a hydrogenation rate of at least 90% or more from the viewpoint of heat resistance, and is preferably 92 to 98%.

  And by adding an unsaturated carboxylic acid metal salt as a co-crosslinking agent to this hydrogenated nitrile rubber (H-NBR), the tensile modulus and hardness are increased. In order to ensure tensile modulus, elongation at break, and higher tear strength and hardness, a composite polymer containing hydrogenated nitrile rubber and unsaturated carboxylic acid metal salt in a mass ratio of 40:60 to 50:50 And a hydrogenated nitrile rubber at a polymer content of 90:10 to 20:80. As a result, it is considered that the unsaturated carboxylic acid metal salt has a higher-order structure in the polymer component, and the unsaturated carboxylic acid metal salt forms a finely dispersed filler in the polymer component. Has higher tensile strength than blending acid metal salts. Moreover, the back surface hardness of the back part 4 can be 83 degrees (JISA type hardness meter) or more. Since the back surface hardness can be 83 degrees (JISA type hardness meter) or more, preferably 87 degrees or more, deformation of rubber can be suppressed even when stress is applied.

  The unsaturated carboxylic acid metal salt is an ionic bond of an unsaturated carboxylic acid having a carboxyl group and a metal. Examples of the unsaturated carboxylic acid include monocarboxylic acids such as acrylic acid and methacrylic acid, maleic acid, fumaric acid, and itacone. Dicarboxylic acids such as acids are preferred, and the metals are beryllium, magnesium, calcium, strontium, barium, titanium, chromium, molybdenum, manganese, iron, cobalt, nickel, copper, silver, zinc, cadmium, aluminum, tin, lead, antimony Etc. can be used.

  In addition, the rubber | gum used as the base material of the toothed belt 1 which concerns on this invention can be suitably selected not only according to the above-mentioned hydrogenated nitrile rubber but according to use conditions. For example, styrene-butadiene-vinylpyridine three-dimensional copolymer (VP), styrene butadiene copolymer (SBR), chloroprene (CR), acrylonitrile butadiene copolymer (NBR), chlorosulfonated polyethylene (CSM), ethylene propylene A diene monomer (EPDM), an ethylene propylene copolymer (EPR), an isopropylene rubber (IR), a natural rubber (NR), a fluorine rubber, a silicon rubber, or the like can be appropriately selected and used.

  Generally, glass fiber and aramid fiber are used for the core wire 3 embedded in the back part 4 configured as described above. Further, any of twisted cords composed of polybenzoxazole, polyparaphenylene naphthalate, polyester, acrylic, carbon, and steel can be used. The composition of the glass fiber may be either E glass or S glass (high-strength glass), and is not limited to the thickness of the filament, the number of converging filaments, and the number of strands.

  As the RFL solution for treating the core wire 3, a mixture of resorcin and formalin initial condensate and rubber latex is used. The molar ratio of resorcin to formalin is preferably 1: 1.5 to 3 in order to increase the adhesive force. The initial condensate of resorcin and formalin is mixed with latex so that the resin content is 2 to 30 parts by mass with respect to 100 parts by mass of the rubber content of the latex, and the total solid concentration is 5 to 40%. Adjusted to concentration. As this latex, styrene / butadiene / vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer and the like can be used.

  And the tooth cloth 5 covered on the surface of the tooth part 2 is formed of a canvas made of a mixed yarn of nylon fiber or aramid fiber and ultrahigh molecular weight polyethylene fiber for one or both of weft and warp. Has been. The form of the fiber may be either a filament yarn or a spun yarn. In addition, the weaving configuration may be any of a twill weave, a hand-woven, a plain weave, and the like. In addition to the nylon fiber or the aramid fiber, any one of polyester, polybenzoxazole, cotton, polyolefin, or a combination thereof can be used as the fiber to be mixed and twisted with the ultrahigh molecular weight polyethylene fiber. By setting it as such a structure, the characteristic of elongation can be 100% or more, further 300% or more, and a tooth | gear can be formed reliably.

  Moreover, it becomes possible to coat | cover the tooth | gear part 2 surface, without decomposing | disassembling at the time of vulcanization | cure. Furthermore, ultra high molecular weight polyethylene fibers are generally non-polar materials and cannot be bonded to hydrogenated nitrile rubber, which is a polar material, but can be bonded to these rubbers by blending with aramid fibers. It becomes possible to adhere and cover the surface of the tooth portion 2 with a high adhesive force. In addition, a part of the ultrahigh molecular weight polyethylene fiber is melted during vulcanization, and a film is formed on the surface of the tooth cloth 5. Thereby, the friction coefficient on the surface of the tooth cloth 5 is greatly reduced.

  Thus, it is preferable that the molecular weight of the ultra high molecular weight polyethylene fiber mixed with nylon fiber or aramid fiber is 2 million to 5 million. If the molecular weight of the ultra high molecular weight polyethylene is 2 million or less, the viscosity at the time of vulcanization will extremely decrease and flow down, and if it is 5 million or more, a resin film cannot be formed.

  An adhesive layer is provided between the tooth cloth 5 and the tooth portion 2. This adhesive layer is formed of either hydrogenated nitrile rubber or urethane elastomer. Thus, the adhesive force between the rubber | gum used as a base material and the tooth cloth 5 can be heightened by forming the contact bonding layer.

  As described above, the toothed belt according to the present invention uses a canvas formed by using a fiber in which a nylon fiber or an aramid fiber and an ultrahigh molecular weight polyethylene fiber are mixed and twisted in one or both of a weft and a warp. Therefore, the adhesive force with the tooth portion is maintained over a long period of time, and in addition, since the coefficient of friction of the surface is low, it can have high silence under a high load over a long period of time.

  By the way, as the above-described core wire 3, it is particularly preferable to use carbon fiber. This core wire 3 is obtained by impregnating a carbon fiber multifilament yarn having a total denier of 1,000 to 40,000 with a treatment liquid composed of a rubber latex and an epoxy resin, and then separating the fiber at 5 to 10 times / 10 cm. Various twisted cords that are twisted or under twisted at 5 to 10 times / 10 cm and further twisted at 2.5 to 5 times / 10 cm may be used.

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, efficiently gathering many filaments, and reducing the space between closely spaced 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 packed in high density, and the tensile elastic modulus of the belt is 50 to 85 N / mm ² . ing. Here, if the cross-sectional shape of the monofilament is an elliptical shape, the monofilaments rub against each other and the cord is likely to break. In the case of other cross-sectional shapes, the space between the filaments when the filaments are gathered becomes large, so that the strength of the cord cannot be sufficiently improved.

  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 with respect to 100 parts by mass of the carbon fiber multifilament yarn. When the content of the treatment liquid is less than 10 parts by mass, the fatigue resistance of the cord may be reduced due to friction between monofilaments. On the other hand, when the content exceeds 40 parts by mass, the heat resistance, water resistance and resistance of the cord are reduced. Solvent property may decrease.

  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 with respect to 100 parts by mass of the treatment liquid (solid content). If the amount is less than 20 parts by mass, the flexibility of the cord may decrease and the bending fatigue resistance of the belt may decrease. On the other hand, if the amount exceeds 80 parts by mass, the adhesiveness of the cord becomes excessive and the handling property is poor. Become.

  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), EPDM rubber latex, or a blend of two or more.

  Content of the epoxy resin in the processing liquid contained in the said processing liquid (solid content) is 20-80 mass parts with respect to 100 mass parts of processing liquid (solid content), Preferably it is 30-70 mass parts. If the amount is less than 20 parts by mass, the adhesion between the cord and the rubber interface may be lowered. If the amount exceeds 80 parts by mass, the flexibility of the cord may be lowered and the bending fatigue resistance of the belt may be lowered.

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

  The surface of the cord is covered with an adhesive layer. This adhesive layer may be a single layer obtained from resorcin-formaldehyde-latex liquid (RFL liquid), or obtained from rubber glue. One layer may be sufficient, and also two layers of the lower layer which consists of RFL liquid, and the upper layer which consists of rubber paste may be sufficient.

  The RFL liquid is a mixture of resorcin and formaldehyde initial condensate and rubber latex. In this case, the molar ratio of resorcin and formaldehyde is 3/1 to 1/3 in order to increase the adhesive strength. Is preferred. Further, an initial condensate of resorcin 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 content of rubber latex, and further, resorcin and formaldehyde containing phenol resin are mixed. The mass ratio of the solid content of the initial condensate and the rubber latex is adjusted to 5/95 to 40/60. If the mass ratio is less than 5/95, the adhesiveness is remarkably lowered. On the other hand, if it exceeds 40/60, the rubber latex content is reduced, so that the heat resistance is deteriorated and the bending fatigue resistance is lowered.

  Examples of rubber latex used in the RFL treatment liquid include hydrogenated nitrile rubber latex (H-NBR latex), styrene-butadiene-vinylpyridine terpolymer (VP latex), chloroprene rubber latex, and EPDM rubber latex. A blend of seeds or more is used. Hydrogenated nitrile rubber latex and vinylpyridine rubber latex are mixed at a mass ratio of solid content of 60/40 to 95/5. When the mass ratio of the hydrogenated nitrile rubber is less than 60/40, the heat resistance is deteriorated and the bending fatigue resistance is lowered. On the other hand, when it exceeds 95/5, the water resistance is markedly lowered.

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

  Further, the treatment cord is dipped in rubber paste to adhere a rubber layer, and then heat-treated through an oven adjusted to 130 to 250 ° C. Here, as the rubber paste, in addition to hydrogenated nitrile rubber (H-NBR), chloroprene rubber (CR), and chlorosulfonated polyethylene rubber (CSM), NBR, ethylene propylene diene monomer (EPDM), ethylene propylene copolymer Rubber blends of coalesced (EPR), SBR, isoprene rubber (IR), and natural rubber (NR) were obtained by dissolving in solvents such as aromatic hydrocarbons such as toluene and xylene.

  Alternatively, the treatment cord may be impregnated with RFL solution in the same manner as described above to form a lower layer, and then an upper layer may be formed on the lower layer by rubber coating.

Hereinafter, the toothed belt of the present invention will be specifically described with reference to examples.
(Examples 1 and 2, Comparative Examples 1 and 2)
Rubbers having the composition shown in Table 1 were kneaded by an ordinary method, and rubber sheets A-1 to A-2 having a predetermined thickness were adjusted with a calender roll. Moreover, the tooth cloth performed the process shown in Table 2 using the fiber shown in Table 2, and obtained B-1 to B-4. The RFL treatment in Table 2 is a treatment in which a tooth cloth is immersed in an RFL treatment liquid composed of C-1 shown in Table 3, dried at 120 ° C. and then heat treated at 180 ° C. for 2 minutes. Further, the rubber paste treatment in Table 2 is carried out by dissolving the rubber compound shown in Table 6 in MEK and toluene as shown in Table 3 and then polyaryl polyisocyanate (trade name) as an isocyanate compound. A treatment liquid in which MBI or N- (1,3-Dimethyl-Butyl) -N′-phenyl-p-phenylenediamine, an antifriction material such as fluororesin powder or graphite is appropriately added and mixed with the treatment liquid to which PAPI) is added. The toothbrush is dipped in and dried. In addition, those using PE as toothbrush fibers may melt if heat-treated at a high temperature of 130 ° C. or higher. Therefore, B-2 and B-3 are indicated by C-4 (trade name Chemlock 225X, etc.) Did. Further, a rubber having the composition shown in Table 6 was kneaded by an ordinary method as an adhesive layer, and a rubber sheet F-1 having a predetermined thickness was obtained with a calendar roll.

  Next, the above-mentioned tooth cloth is wound around a ZBS tooth mold 120 for forming a belt, and a rubber paste and phenol resin in which a pair of SZ twisted RFL and hydrogenated nitrile rubber are dissolved in a solvent such as toluene. The core wire shown in Table 4 subjected to the adhesion treatment was wound around the spiral with a predetermined tension at the pitch shown in Table 5. The rubber sheet of Table 1 was affixed on this core wire. Furthermore, after putting into a vulcanizing can and forming a tooth profile by a normal press-fitting method, pressure vulcanization is performed at 165 ° C. for 30 minutes, and the belt back surface is polished to a certain thickness and cut to a certain width (30 mm). Thus, a toothed belt for traveling was obtained. Table 7 shows the back hardness of each belt.

  The produced belt has a belt width of 15 mm, a belt tooth profile ZBS, a tooth number of 120 teeth, and a tooth pitch of 9.525 mm, and is normally displayed as 120 ZBS30. As the running test apparatus, a test apparatus having a layout including a 22-tooth crank pulley 14, a 44-tooth cam pulley 11, a 19-tooth water pump pulley 13, an eccentric pulley 12, and an idler 15 shown in FIG. A running test was performed with an effective tension applied to the belt of 3700 N at a crank pulley rotational speed of 4000 rpm and an initial tension of 350 N.

  From Table 7, in Comparative Examples 1 and 2, the belt breaks early, whereas in the toothed belts of Examples 1 and 2 in which the ultrahigh molecular weight polyethylene fiber forms a film on the surface of the tooth cloth, the belt breakage time is greatly increased. You can see that it has improved.

(Examples 3-5, Comparative Examples 3-5)
Next, as Examples 3 to 5, carbon fiber non-twisted multifilament yarn (T700GC · 6K · 31E (model number, manufactured by Toray Industries, Inc.) fineness 4,300 denier) was treated with a treatment liquid (fixed component concentration 40 mass). After passing through a treatment liquid tank containing 200 parts by mass of a vinylpyridine-styrene-butadiene rubber latex (manufactured by JSR Corporation) and 200 parts by mass of ethylene glycol diglycidyl ether in 500 parts by mass of water and impregnating them. And heat treatment through an oven adjusted to 140 ° C. Subsequently, the multifilament yarn subjected to the above treatment was twisted at 5 times / 10 cm to form a cord, and then the cord was immersed in the RFL solution shown in Table 8 and heat-treated in the range of 130 to 180 ° C. An adhesive layer was formed.

  The result of having measured the relationship between the number of single twists of the said process cord and the strength with an autograph is shown in FIG. According to this, it is understood that high strength can be maintained if the number of twists is 5 to 10 times / 10 cm in the single-stranded cord.

  As a rubber sheet for the tooth part and the back part, rubbers having the composition shown in Table 1 were kneaded by a usual method and adjusted to a predetermined thickness by a calendar roll. As the tooth cloth, a tooth cloth having the same material and processing method as the tooth cloth used in Example 1 was used.

  Next, the tooth cloth is wound around a mold having 120 teeth of STPD tooth profile for belt preparation, and a pair of SZ twisted carbon fiber cords (number of twists of 5 times / 10 cm) as a core wire is 1.0 mm / pitch. And wound around the spiral with a predetermined tension. A rubber sheet shown in Table 1 was wrapped around the core wire, and a jacket was put on and put into a vulcanizing can and pressure vulcanized 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 traveling toothed belt.

  There are three types of belts produced: belt width 10.0 mm, belt tooth profile STPD, number of teeth 120, type 1 (Example 3) with tooth pitch 5.00 mm, belt width 19.0 mm, belt tooth profile STPD, number of teeth 105 Teeth, Type 2 (Example 4) with a tooth pitch of 8.00 mm, and Type 3 (Example 5) with a belt width of 30.0 mm, a belt tooth profile STPD, 100 teeth, and a tooth pitch of 14.00 mm.

  On the other hand, as Comparative Examples 3 to 5, after three untwisted glass fibers (E-glass) as core wires were aligned, they were immersed in the RFL treatment liquid shown in Table 2 and then heat treated at 200 to 280 ° C. . This was twisted in the S direction and Z direction at a twist number of 8 times / cm to prepare a cord. 11 of these were aligned and twisted at 12 times / cm. Furthermore, this was immersed in rubber paste and heat-treated in the range of 130 to 180 ° C. The rubber A-1 in Table 1 was used as the rubber, and the canvas B-1 in Table 2 was used as the tooth cloth. Moreover, the tooth cloth process performed the process similar to the comparative example 1. FIG. Then, three kinds of toothed belts were produced under the same production conditions as in Examples 3 to 5 described above.

  There are three types of belts produced: belt width 10.0 mm, belt tooth profile STPD, 120 teeth, type 1 (comparative example 3) with tooth pitch 5.00 mm, belt width 19.0 mm, belt tooth profile STPD, teeth 105 Teeth, type 2 (comparative example 4) with a tooth pitch of 8.00 mm, and type 3 (comparative example 5) with a belt width of 30.0 mm, a belt tooth profile STPD, 100 teeth, and a tooth pitch of 14.00 mm.

  The cord diameter, the cross-sectional area of the cord, the fiber cross-sectional area occupancy in the cord cross-sectional area, and the belt elastic modulus (per width) of the above-described Examples 3 to 5 and Comparative Examples 3 to 5 were obtained. Table 9 shows. The belt elastic modulus was measured by an autograph at room temperature with respect to the relationship between the belt axial distance change rate and the axial load.

  According to this result, it can be seen that the toothed belts according to Examples 3 to 5 have higher strength and higher elastic modulus than those of Comparative Examples 3 to 5, and the elongation is small. Dimensional change is reduced. Moreover, about the fiber cross-sectional area occupation rate in a cord cross-sectional area, it turns out that the carbon fiber cord of Examples 3-5 has a high fiber filling rate compared with the glass fiber cord of Comparative Examples 3-5. .

  In addition, a jumping test was performed to compare the transmission capacity of toothed belts. In this jumping test, the load on the driven shaft was increased while the belt was running, and the load value when jumping (tooth skipping) occurred was measured. As test conditions, the toothed belts of Example 3 and Comparative Example 3 were suspended on a 22-tooth drive pulley and a 20-tooth driven pulley, and the 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 10.

  According to this result, it can be seen that the toothed belt of Example 3 is less likely to cause jumping and has a larger load transmission capacity than the toothed belt of Comparative Example 3.

The toothed belt of the present invention can be used for a drive device that drives a driven robot arm by rotation on the drive side, a drive device for an overhead camshaft of an automobile, or the like. In particular, in the toothed belt, the ratio of the fiber cross-sectional area to the cord cross-sectional area is set to 70 to 90%, and the carbon fiber is filled with a high density so that the tensile elastic modulus of the belt is 50 to 85 N / mm ² . Can be set. As a result, the extension of the core wire can be reduced to suppress the overshoot on the driven side at the time of starting / stopping the drive device, and the responsiveness can be increased, and the load transmission capacity can be increased.

1 is a schematic perspective view of a toothed belt according to the present invention. It is the schematic of the running test apparatus of a toothed belt. It is a figure which shows the relationship between the number of single twists of the core wire processing cord of a toothed belt, and strength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Toothed belt 2 Tooth part 3 Core wire 4 Back part 5 Tooth cloth 6 Weft 7 Warp

Claims (9)

A plurality of rubber-based tooth portions arranged at predetermined intervals along the longitudinal direction, and a back portion based on rubber embedded with a core wire;
The tooth cloth covering the surface of the tooth part is a canvas formed by using a fiber in which nylon fiber or aramid fiber and ultrahigh molecular weight polyethylene fiber are mixed and twisted in either or both of a weft and a warp,
A toothed belt , wherein a part of the ultrahigh molecular weight polyethylene fiber is melted to form an ultrahigh molecular weight polyethylene film on the tooth cloth surface.   The rubber is a composite polymer body in which a hydrogenated nitrile rubber and an unsaturated carboxylic acid metal salt are blended in a mass ratio of 40:60 to 50:50, and the composite polymer body and the hydrogenated nitrile rubber are in a mass ratio of 90:10. The toothed belt according to claim 1, which is blended at -20: 80.   The toothed belt according to claim 1, wherein an adhesive layer is provided between the tooth cloth and the tooth portion, and the adhesive layer is either hydrogenated nitrile rubber or urethane elastomer.   The toothed belt according to any one of claims 1 to 3, wherein the ultra high molecular weight polyethylene fiber has a molecular weight of 2 million to 5 million. The core wire is impregnated with a treatment liquid composed of rubber latex and epoxy resin on a multifilament yarn of carbon fiber having a total denier of 1,000 to 40,000, and then twisted 5-10 times / 10 cm. And the ratio of the fiber cross-sectional area to the cross-sectional area of the cord 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 4. The core wire is impregnated with a treatment liquid composed of rubber latex and epoxy resin on a multifilament yarn of carbon fiber having a total denier of 1,000 to 40,000, and then twisted 5-10 times / 10 cm. Further, the cord is twisted at 2.5 to 5 times / 10 cm and coated with an adhesive layer on its surface, and the ratio of the fiber cross-sectional area to the cord cross-sectional area is 70 to 90%, and , toothed belt according to any one of claims 1 to 4 tensile modulus of the belt is 50~85N / mm ^2.   The toothed belt according to claim 5 or 6, wherein the adhesive layer is a single layer obtained from a resorcin-formaldehyde-latex solution.   The toothed belt according to claim 5 or 6, wherein the adhesive layer comprises two layers, a lower layer made of resorcin-formaldehyde-latex liquid and an upper layer made of rubber glue. The toothed belt according to any one of claims 1 to 8, wherein the hardness of the back portion is 83 degrees or more by a JISA type hardness meter.

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