JP3923818B2 - Power transmission belt - Google Patents

Description

【００３５】
【表２】

【００３６】
【表３】

【００３７】
【表４】

【００３８】
【表５】

【００３９】
次に、上記コードを用いて歯付ベルトを作製した。
ＲＦＬ処理したアラミド繊維からなる帆布を経糸がベルトの幅方向に沿うように、緯糸を周方向としたエンドレスの筒状にして金型にセットし、帆布上に上記各心線を交互に０．５ｍｍピッチで配置するように巻き付け、さらにこの上から表４に示すゴム組成物からなる圧延シートを巻き付け、加圧・加硫することによって、スリーブ状の成形品を作製した。これを所定幅に切断することによって、ベルト幅１９．１ｍｍ、歯ピッチ８ｍｍ、歯数９９の歯付ベルトを得た。そして以下の性能について試験した。
【００４０】
１．処理コード引張強力
ＪＩＳ Ｌ１０７１に基づき、処理コード引張強力を測定した。
【００４１】
２．処理コード剥離力
処理繊維コードを２密に並べて表４に示すゴム配合物に温度１５３°Ｃ、圧力２ＭＰａで３０分間加圧密着させた後、幅２５ｍｍに裁断し、長さ１４０ｍｍ、厚さ４ｍｍのシート状試料を作製した。室温で引張試験機を用いて平剥離力を測定し、処理コードとゴムとの接着力を評価した。
【００４２】
３．ベルト強力
ベルトを５０ｍｍ／分の速度で引っ張って、ベルトが切断したときの最大荷重を求めた。
【００４３】
４．ベルトモジュラス
ベルトのＳＳ曲線を作成し、そのＳＳ曲線の直線部分の傾きを算出した。
【００４４】
５．ベルト強力保持率
図３に示すレイアウトに従い室温雰囲気下で２００時間走行試験を実施した後、走行後のベルトの強力を測定した。そして、走行後のベルト強力を走行前のベルト強力で除してベルト強力保持率を求めた。
【００４５】
結果、ポリパラフェニレンベンゾビスオキサゾール繊維で構成した子縄がコア部、ガラス繊維で構成した子縄がスキン部となるよう構成した心線を用いた実施例１の歯付ベルトは、ガラス繊維で構成した心線を用いた比較例１の歯付ベルトと比べて、同一のベルト幅であっても、引張強力、ベルトモジュラスに優れており、ほぼ同等のベルト強力保持率を有することが確認できた。つまり実施例は省スペース化の要求に適したベルトであることが判る。また、ＰＢＯ繊維子縄単独で構成された比較例２はゴム−心線間の接着力が極端に低いものの、実施例は非常に優れた接着性を示すことが確認できた。
【００４６】
【発明の効果】
以上のように、本願請求項記載の発明では、ベルト長手方向に沿って心線を埋設した接着ゴム層と、圧縮ゴム層から構成される動力伝動ベルトにおいて、前記動力伝動ベルトは、前記ゴム層を形成するベルト本体が、ベルト長手方向に沿って設けられる複数の歯部と、補強用心線を埋設した背部から構成される歯付ベルトであり、前記心線が、ポリパラフェニレンベンゾビスオキサゾール繊維とガラス繊維で構成されるコードであって、ポリパラフェニレンベンゾビスオキサゾール繊維がコア部、ガラス繊維がスキン部となるよう構成したことを特徴とする動力伝動ベルトであり、高強力、高モジュラスであるとともに、走行後のベルト強力低下が小さく、優れた耐屈曲疲労性を充足できる効果がある。
【図面の簡単な説明】
【図１】本発明に係る歯付ベルトの断面斜視図である。
【図２】本発明に係る動力伝動ベルトで用いられる心線の断面図である。
【図３】歯付ベルトの走行試験装置のレイアウトである。
【符号の説明】
１ 歯付ベルト
２ 歯部
３ 心線
４ 背部
５ 基布
６ スキン部
７ コア部
８ 子縄（ＰＢＯ繊維）
９ 子縄（ガラス繊維）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power transmission belt, and more particularly to a power transmission belt suitable for a drive device that requires high strength and high modulus performance.
[0002]
[Prior art]
In general, in a transmission belt such as a toothed belt, a V belt, and a V-ribbed belt, a cord is embedded as a reinforcing core in a main body made of a rubber composition. The cord is a member that bears most of the belt tension, and its characteristics are determined by a combination of the type of fiber and the number of twists, twist direction, fineness, and the like. As a fiber type constituting the cord, a twisted cord composed of a high modulus fiber such as polyester, glass, or aramid fiber is generally used.
[0003]
As a layout for using these power transmission belts, for example, toothed belts, it has been common to hang belts on drive shafts and driven shafts and to provide tensioners to keep tension constant. However, in recent years, the tensioner cannot be installed due to the reduction of installation space due to the downsizing of the equipment and the reduction of parts due to cost reduction, and there are many cases where the tensioner is used in the layout by fixing between axes, and the dimensional change with time There is a demand for a belt with a small amount. In addition, there is a demand for narrower belts as the apparatus becomes more compact.
[0004]
However, when a conventional belt is examined, a transmission belt using a polyester fiber cord has a problem that the bending fatigue resistance is very good, but the dimensional stability is poor and high positioning accuracy cannot be obtained. . In addition, a transmission belt using an aramid fiber cord has characteristics such as high strength and excellent bending fatigue, but there is a problem that a dimensional change with time due to moisture absorption is large.
[0005]
On the other hand, a transmission belt using a glass fiber cord has characteristics such as excellent dimensional stability and temporal dimensional stability. However, the demands for strength and modulus have increased further with the recent advancement of high-performance and high-performance precision equipment. If the fineness of the cord is set higher than the general-purpose value in order to meet these demands, bending fatigue resistance will be increased. There was a problem of a drop. In addition, if the belt is designed to be wide and the number of core wires embedded in the main body is increased, there is an adverse effect such that the engine room can be saved in space.
[0006]
Against this background, in recent years, polyparaphenylene benzobisoxazole fibers (PBO fibers) having higher modulus and strength than conventional ordinary fibers have attracted attention. In particular, the strength and elastic modulus surpasses that of aramid fiber. In the industrial belt industry, this PBO fiber is used as a core wire, which increases the strength and modulus of the cord without increasing the fineness of the cord and the space in the engine room. It is expected that a simple power transmission belt can be provided. However, since PBO fiber contains almost no functional groups on its molecular skeleton, it has poor adhesion to rubber compared to conventional short fibers, and it is considered difficult to realize a cord-rubber composite. It was.
[0007]
Therefore, in order to improve the adhesion to rubber, it has been proposed to perform a special adhesion treatment on the PBO fiber. For example, in JP-A-9-176332, after treatment with a first treatment liquid comprising an epoxy compound, rubber latex, and a heat-reactive water-soluble urethane resin, a second treatment liquid comprising resorcin, formalin, and rubber latex is used. A technique for improving adhesion to rubber by processing is disclosed.
[0008]
[Problems to be solved by the invention]
However, even if the above-described technique is applied to the PBO short fibers, the adhesive strength with the rubber composition is not sufficiently satisfactory, and there is a problem in practical use.
In addition, the belt used in a layout with a fixed inter-axis distance needs to have a small dimensional change over time and a low rate of decrease in tension after running, but when examining a conventional belt made of PBO fibers, It was found that there was a problem with bending fatigue resistance.
[0009]
The present invention has been made in view of such various points, and provides a power transmission belt that has high strength and high modulus, has a small decrease in belt strength after traveling, and satisfies excellent bending fatigue resistance. is there.
[0010]
[Means for Solving the Problems]
That is, the invention according to claim 1 of the present application is a power transmission belt composed of an adhesive rubber layer having a core wire embedded along the longitudinal direction of the belt and a compression rubber layer, wherein the power transmission belt forms the rubber layer. The belt body is a toothed belt composed of a plurality of tooth portions provided along the belt longitudinal direction and a back portion in which a reinforcing core wire is embedded, and the core wire includes polyparaphenylene benzobisoxazole fiber and glass A cord composed of fibers, characterized in that the polyparaphenylene benzobisoxazole fiber is a core part and the glass fiber is a skin part.
[0011]
The invention according to claim 2 of the present application is the power transmission belt according to claim 1, wherein the core wire is formed by twisting a strand composed of polyparaphenylene benzobisoxazole fiber and a strand composed of glass fiber. It is a twisted cord, and is characterized in that a strand made of polyparaphenylene benzobisoxazole fiber is a core portion and a strand made of glass fiber is a skin portion.
[0012]
The invention according to claim 3 of the present application is characterized in that, in the power transmission belt according to claim 1 or 2, the skin portion and the core portion are configured using a flyer twisting machine.
[0013]
The invention according to claim 4 of the present application is the power transmission belt according to claim 2 , wherein the twisted cord is twisted in the opposite direction to the twisted cord and the twisted cord is twisted in the opposite direction. .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a toothed belt 1 according to the present invention.
The toothed belt 1 is composed of a belt body including a plurality of tooth portions 2 along the belt longitudinal direction and a back portion 4 in which a reinforcing core body 3 is embedded in a spiral shape on the belt pitch line of the belt body. A base fabric 5 is attached to the surface of the tooth portion 2.
[0015]
The base fabric 5 is a base fabric selected from woven fabrics, knitted fabrics, non-woven fabrics and the like. As the fiber material constituting the base fabric, publicly known and publicly available materials can be used. For example, natural fibers such as cotton and hemp, inorganic fibers such as metal fibers and glass fibers, and polyamide, polyester, polyethylene, polyurethane, polystyrene, Examples thereof include organic fibers such as polyfluoroethylene, polyacryl, polyvinyl alcohol, wholly aromatic polyester, and aramid, and it is preferable to use a woven fabric in which these are woven into plain weave, twill weave, satin weave, or the like.
[0016]
The form of the fiber is not limited to spun yarn, multifilament yarn, monofilament yarn, etc., but when the monofilament yarn is used as the constituent yarn, the unevenness caused by the intersection of the warp and weft is increased, and the surface friction coefficient is reduced. Good wear resistance and tooth chipping resistance. In addition, it is an effective means for reducing the surface friction coefficient to lower the weave density or to use a fiber having a large diameter.
In addition, since the shrinkage is required in the weft direction of the base fabric at the time of molding by the press-fitting method used as a publicly known technique, the crimped 6 nylon or the weft yarn along the longitudinal direction of the belt body is used. It is preferable to use composite yarn twisted with 66 nylon or urethane elastic yarn. Further, when monofilament yarn is used for the base fabric 5, it is desirable to use it for warp so as not to affect the shrinkage in the weft direction.
[0017]
The base fabric 5 is immersed in a resorcin-formalin-latex solution (RFL solution) according to a known technique, and then friction is applied by rubbing unvulcanized rubber into the base fabric 5, or after being immersed in the RFL solution, the rubber is dissolved in a solvent. Soak in a soaking solution. Moreover, you may perform an adhesion | attachment process only with RFL liquid.
[0018]
The RFL liquid is a mixture of resorcin and formalin initial condensate and rubber latex, and the molar ratio of resorcin and formalin is preferably 1: 0.5 to 3 in order to increase the adhesive force. The initial condensate of resorcin and formalin is mixed with the latex so that the resin content is 10 to 100 parts by weight with respect to 100 parts by weight of the latex rubber, and the total solid concentration is 5 to 40. % Concentration is adjusted. The RFL solution may be appropriately mixed with a carbon black solution to blacken the treatment, or a known surfactant may be added in an amount of 0.1 to 5.0% by weight.
Examples of the latex include styrene-butadiene-vinylpyridine terpolymer, chlorosulfonated polyethylene, hydrogenated nitrile rubber, epichlorohydrin, natural rubber, SBR, chloroprene rubber, olefin-vinyl ester copolymer, EPDM, and the like. Latex.
[0019]
The belt body composed of the back portion 4 and the tooth portion 2 is formed of a rubber layer, and is made of natural rubber (NR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), chlorosulfonated polyethylene (CSM). ), Alkylated chlorosulfonated polyethylene (ACSM), nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), hydrogenated nitrile rubber blended with unsaturated carboxylic acid metal salt, ethylene propylene diene monomer (EPDM) ), Rubber selected from butyl rubber (IIR) and the like can be used alone or in a blend. Alternatively, it is possible to use polyurethane rubber in addition to these rubbers. In particular, in the case of a toothed belt, it is desirable to use a rubber having improved heat aging resistance. In the case of a hydrogenated nitrile rubber, the hydrogenation rate is 80% or more, and the heat resistance and ozone resistance characteristics are exhibited. For that purpose, 90% or more is more preferable. Hydrogenated nitrile rubber having a hydrogenation rate of less than 80% has extremely low heat resistance and ozone resistance.
[0020]
The rubber is added and mixed with a reinforcing agent such as carbon black, a filler, a softening agent, an anti-aging agent, a vulcanization aid, a vulcanizing agent such as sulfur or an organic peroxide, and the like. When an organic oxide is blended as a crosslinking agent, 0.2 to 10 mass of organic peroxide is added to 100 mass parts of the polymer component in order to ensure a predetermined modulus (tensile modulus) and elongation at break. It is necessary to mix partly and crosslink. The organic peroxide is not particularly limited, and specifically, di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, 1,1-t-butylperoxy-3,3 , 5-trimethylcyclohexane, 2,5-di-methyl-2,5-di (t-butylperoxy) hexane, 2,5-di-methyl-2,5-di (t-butylperoxy) hexane-3, bis ( Use t-butylperoxydi-isopropyl) benzene, 2,5-di-methyl-2,5-di (benzoylperoxy) hexane, t-butylperoxybenzoate, t-butylperoxy-2-ethyl-hexyl carbonate, etc. be able to. In addition to such organic peroxides, metal oxides, sulfur compounds, oxime nitroso compounds, monomers, and polymers that are commonly used as co-crosslinking agents may be added in appropriate amounts.
[0021]
As the core 3, a cord composed of polyparaphenylene benzobisoxazole fiber (PBO fiber) and glass fiber, the cord configured such that the PBO fiber becomes the core portion 7 and the glass fiber becomes the skin portion 6 is used. It is done. The composition of the glass core wire may be either E glass or S glass (high strength glass), and is not limited by the thickness of the filament, the number of converged filaments and the number of strands. Further, it is not limited to a sizing agent, RFL, overcoat agent or the like used as an adhesive treatment agent or a protective material for a glass filament during bending.
The PBO fiber can be obtained by spinning a polymer obtained by condensation polymerization of diaminoresorcinol and terephthalic acid in a polyphosphoric acid solvent. It has higher physical property values than conventional ordinary fibers. For example, it exhibits strength and elastic modulus higher than aramid fiber in mechanical properties. However, there is a problem that adhesion to rubber is difficult compared to conventional fibers because it contains almost no functional groups on its molecular skeleton. Therefore, it is possible to improve the adhesive strength between the cord and rubber by placing glass fiber on the cord surface layer, that is, the skin portion 6, and high strength and high modulus can be achieved by placing PBO fiber on the cord core portion, that is, the core portion 7. And
[0022]
Specifically, the core wire 3 is a twisted cord formed by twisting a strand 8 composed of PBO fibers and a strand 9 composed of glass fibers as shown in FIG. 2, and is composed of PBO fibers. A structure in which a lasso 8 is a core portion 7 and a lasso 9 made of glass fiber is a skin portion 6 is used. The said core wire is produced using a fryer twister, for example.
[0023]
The cord may be set so that the fineness of the PBO fiber strand is 200 to 1,700 dtex, the fineness of the glass fiber strand is 400 to 3,500 dtex, and the total fineness number is 4,000 to 12,000 dtex. It is preferable for extending the belt life. The number of upper twists of the cord is preferably 50 to 120 times / m, and the number of lower twists is 50 to 200 times / m for the strands made of PBO fiber and 50 to 200 times for the strands made of glass fiber. It is desirable to set to be times / m. It is also possible to provide a medium twist between the upper twist and the lower twist. Further, it is preferable that the upper twist is twisted in the direction opposite to the lower twist, that is, twisted.
[0024]
The core wire 3 is subjected to an adhesion treatment for the purpose of improving the adhesion to rubber. As such an adhesion treatment, it is common to immerse the fiber in a resorcin-formalin-latex (RFL) solution and then heat-dry to form a uniform adhesion layer on the surface. However, the present invention is not limited to this, and there is also a method of performing a pretreatment with an epoxy or isocyanate compound and then treating with an RFL solution.
[0025]
As a specific method, after impregnating the untreated cord with a pretreatment liquid selected from an epoxy compound or an isocyanate compound and pre-dipping, the cord is passed through a drying furnace set at a temperature of 160 to 200 ° C. for 30 to 600 seconds. Dry and subsequently impregnate an adhesion treatment consisting of RFL liquid. Further, after this, it is possible to post-process with rubber glue. The processing procedure is not limited to the above, and for example, a cord that is pre-dip treated may be twisted into a cord, and the cord may be subjected to RFL processing. In addition, when pre-dip treatment is applied to the lasso, even if the same pre-dip treatment is applied to each of the PBO and glass fiber lasso, different pre-dip treatment is applied to each lasso, or pre-dip treatment is applied only to one. May be applied. PBO fibers are preferably subjected to a pre-dip treatment with a pretreatment liquid composed of a nitrile rubber-modified epoxy resin, an alkylphenol / formaldehyde resin, a cross-linking agent, and a solvent in order to increase the adhesive strength.
[0026]
Examples of the epoxy compound include reaction products of polyhydric alcohols such as ethylene glycol, glycerin and pentaerythritol, polyalkylene glycols such as polyethylene glycol and halogen-containing epoxy compounds such as epichlorohydrin, resorcin, bis (4-hydroxy Phenyl) dimethylmethane, a reaction product with polyhydric phenols such as phenol / formaldehyde resin, resorcin / formaldehyde resin, and halogen-containing epoxy compounds. This epoxy compound is used by mixing with an organic solvent such as toluene or methyl ethyl ketone. Examples of the isocyanate compound include 4,4′-diphenylmethane diisocyanate, 2,4-diisocyanate, P-phenyl diisocyanate, and polyaryl polyisocyanate. This isocyanate compound is also used by mixing with an organic solvent such as toluene or methyl ethyl ketone.
[0027]
The latex used in the RFL solution is chloroprene, styrene / butadiene / vinylpyridine terpolymer, hydrogenated nitrile, NBR, or the like.
[0028]
The cord processed as described above can be finished into a belt with a high modulus by setting the spinning pitch, that is, the winding pitch of the core wire, to 1.0 to 1.3 mm. If the length is less than 1.0 mm, the cord cannot ride on the adjacent cord and cannot be wound. On the other hand, if the length exceeds 1.3 mm, the modulus of the belt gradually decreases.
[0029]
As a manufacturing method of a toothed belt, it is generally manufactured by a press-fitting method. That is, a canvas forming a tooth cloth is wound around a cylindrical mold having a groove portion corresponding to a tooth portion of a toothed belt to be formed on the outer periphery, and a rope that becomes a core wire is wound in order in a spiral shape, and further thereon Wind an unvulcanized rubber sheet that forms the teeth and back. The mold is transferred into a vulcanizing can and heated and pressurized to press the rubber sheet into the mold groove to form a tooth portion. Individual toothed belts are obtained by cutting the obtained sleeve-shaped molded body into a ring with a cutter according to a predetermined width.
[0031]
【Example】
Hereinafter, the present invention will be described in more detail with reference to specific examples.
Example 1
As a core wire, as shown in Table 1, one bundle of 545 dtex PBO fiber multifilament (trade name: Zylon) was prepared, immersed in the pre-dip solution shown in Table 2, and then heat treated at 200 ° C. for 1 minute. Next, after being immersed in the RFL solution shown in Table 3, it was further heat-treated at 230 ° C. for 1 minute. The treated yarn was subjected to a primary twist of 120 times / m to obtain a PBO fiber strand. Moreover, after preparing the glass fiber of ECG-150 and immersing it in the RFL liquid shown in Table 3 in the state where the three were aligned, it was heat-treated at 230 ° C. for 1 minute. The treated raw yarn was subjected to a preliminary twist of 120 times / m to obtain a glass fiber cord. And after twisting together 4 PBO strands and 9 glass strands into various twists using a fryer twisting machine, it is immersed in the treatment liquid shown in Table 5 and heat treated at 160 ° C. for 3 minutes, and treated cord Was made.
[0032]
Comparative Example 1
As a core wire, as shown in Table 1, one bundle of ECG-150 glass fibers was prepared, and three glass fibers were aligned and immersed in the RFL solution shown in Table 3, followed by heat treatment at 230 ° C. for 1 minute. The treated raw yarn was subjected to a preliminary twist of 120 times / m to obtain a glass fiber cord. And after twisting 13 said strands in various twists, it was immersed in the process liquid shown in Table 5, and heat-processed at 160 degreeC for 3 minute (s), and produced the process cord.
[0033]
Comparative Example 2
As a core wire, as shown in Table 1, a bundle of 1,090 dtex PBO fiber multifilament (trade name: Zylon) was prepared, immersed in the pre-dip solution shown in Table 2, and then heat treated at 200 ° C for 1 minute did. Next, after immersing in the RFL solution shown in Table 3, it was further heat-treated at 230 ° C. for 1 minute, and then subjected to 45 twists / m of twisting to give a PBO fiber rope. And after twisting three said strands in Lang twist, it was immersed in the process liquid shown in Table 5, and it heat-processed at 160 degreeC for 3 minute (s), and produced the process cord.
[0034]
[Table 1]

[0035]
[Table 2]

[0036]
[Table 3]

[0037]
[Table 4]

[0038]
[Table 5]

[0039]
Next, a toothed belt was produced using the cord.
An RFL-treated canvas made of aramid fibers is set in an endless cylindrical shape with a weft thread in the circumferential direction so that the warp runs along the width direction of the belt. Wrapped so as to be arranged at a pitch of 5 mm, and further rolled a rolled sheet made of the rubber composition shown in Table 4 from above, and pressurized and vulcanized to produce a sleeve-shaped molded product. By cutting this into a predetermined width, a toothed belt having a belt width of 19.1 mm, a tooth pitch of 8 mm, and 99 teeth was obtained. The following performance was tested.
[0040]
1. Treatment cord tensile strength The treatment cord tensile strength was measured based on JIS L1071.
[0041]
2. Treated cord peeling force Treated fiber cords are arranged in two densely and pressure-adhered to a rubber compound shown in Table 4 at a temperature of 153 ° C. and a pressure of 2 MPa for 30 minutes, then cut to a width of 25 mm, a length of 140 mm, a thickness of 4 mm A sheet-like sample was prepared. The flat peel strength was measured using a tensile tester at room temperature, and the adhesive strength between the treated cord and rubber was evaluated.
[0042]
3. The maximum load when the belt was cut was obtained by pulling the belt strong belt at a speed of 50 mm / min.
[0043]
4). The SS curve of the belt modulus belt was created, and the slope of the straight line portion of the SS curve was calculated.
[0044]
5. Belt strength retention The belt strength after running was measured after running for 200 hours at room temperature according to the layout shown in FIG. Then, the belt strength retention rate was obtained by dividing the belt strength after traveling by the belt strength before traveling.
[0045]
As a result, the toothed belt of Example 1 using the core wire configured such that the strand formed of the polyparaphenylenebenzobisoxazole fiber becomes the core portion and the strand formed of the glass fiber becomes the skin portion is made of glass fiber. Compared to the toothed belt of Comparative Example 1 using the constructed core wire, even with the same belt width, it has excellent tensile strength and belt modulus, and it can be confirmed that it has almost the same belt strength retention rate. It was. That is, it can be seen that the embodiment is a belt suitable for the demand for space saving. Moreover, although the comparative example 2 comprised only with the PBO fiber strand has the extremely low adhesive force between rubber | gum and a core wire, it has confirmed that an Example showed the very outstanding adhesiveness.
[0046]
【The invention's effect】
As described above, in the invention described in the claims of the present application, in the power transmission belt including the adhesive rubber layer in which the core wire is embedded along the belt longitudinal direction and the compression rubber layer, the power transmission belt is the rubber layer. Is a toothed belt composed of a plurality of tooth portions provided along the belt longitudinal direction and a back portion in which a reinforcing core wire is embedded, and the core wire is a polyparaphenylene benzobisoxazole fiber Is a power transmission belt characterized in that the polyparaphenylene benzobisoxazole fiber is the core part and the glass fiber is the skin part, and has high strength and high modulus. In addition, the belt strength decrease after running is small, and there is an effect that excellent bending fatigue resistance can be satisfied.
[Brief description of the drawings]
FIG. 1 is a cross-sectional perspective view of a toothed belt according to the present invention.
FIG. 2 is a cross-sectional view of a core wire used in the power transmission belt according to the present invention.
FIG. 3 is a layout of a running test apparatus for a toothed belt.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Toothed belt 2 Tooth part 3 Core wire 4 Back part 5 Base cloth 6 Skin part 7 Core part 8 Lope (PBO fiber)
9 Lasso ( glass fiber)

Claims (4)

In a power transmission belt composed of an adhesive rubber layer in which a core wire is embedded along the belt longitudinal direction, and a compression rubber layer,
The power transmission belt is a toothed belt in which a belt body forming the rubber layer is composed of a plurality of tooth portions provided along a belt longitudinal direction and a back portion in which a reinforcing core wire is embedded,
The core is a cord composed of polyparaphenylene benzobisoxazole fiber and glass fiber, wherein the polyparaphenylene benzobisoxazole fiber is a core part and the glass fiber is a skin part. Power transmission belt.   The cord is a twisted cord formed by twisting a strand composed of polyparaphenylene benzobisoxazole fiber and a strand composed of glass fiber, and the strand composed of polyparaphenylene benzobisoxazole fiber The power transmission belt according to claim 1, wherein the rope is configured such that the core is a core portion and the cord rope formed of glass fiber is a skin portion.   The power transmission belt according to claim 1 or 2, wherein the skin portion and the core portion are configured using a flyer twisting machine. The power transmission belt according to claim 2, wherein the twisted cord is twisted in the opposite direction to the twisted cord and the twisted cord.

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