JP2004332160A - Cover cloth for toothed belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cover cloth by which a toothed belt having excellent heat resistance and durability is produced. <P>SOLUTION: The cover cloth is used for the toothed belt which includes a core wire for reinforcement embedded in the longitudinal direction of the belt, and has many tooth parts arranged at a prescribed pitch in the longitudinal direction of the belt, and the surface of the tooth part of which is covered with the cover cloth. The cover cloth is obtained by weaving or knitting a filament crimped yarn of a heat-resistant highly functional fiber, having 4-78% elongation recovery measured based on JIS K 1013. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００６１】
【表２】

【００６２】
［実施例４］
パラ系アラミド繊維ＫＥＶＬＡＲ（Ｒ）２２ｔｅｘ糸条にダブルツイスターで１６６２（回／ｍ）すなわち撚り係数Ｋ＝７８００の撚りを加えた他は、実施例１と同様の方法で作製したパラ系アラミド繊維ＫＥＶＬＡＲ （Ｒ）捲縮糸２２ｔｅｘ（フィラメント数１３３本、伸縮復元率８％）を用いて、ゲージ数１６の丸編み機で編み組織インターロック（スムス）の丸編み地を編み上げ、精練してカバークロスとした。このカバークロスに実施例１と同様にエポキシ処理を行い、次いでＲＦＬ接着処理を行って接着処理したカバークロスを調製した。
【００６３】
また、ベルトの芯線には次のように調整したものを用いた。
ＥＣＧ１５０のガラス繊維を３本引き揃え、レゾルシン−ホルマリン−ラテックス液（ＲＦＬ液）で処理し、風乾後２８０℃で１．５分間熱処理したものを、Ｓ方向、Ｚ方向にそれぞれ１２回／１０ｃｍの割合で下撚りして撚られた子縄を１１本ずつ用意し、下撚りがＳ方向の小縄をＺ方向に、下撚りがＳ方向の小縄をＺ方向にそれぞれ８回／１０ｃｍの割合で上撚りした。
【００６４】
得られた接着処理したカバークロス、芯線を用いて、ベルト幅１９．１ｍｍ、端数１６３、歯ピッチ８ｍｍのウレタン樹脂製歯付きベルトを、実施例１と同様の方法で作製した。このようにして得られた歯付きベルトの耐久時間は１４０時間と耐久性良好であった。
【００６５】
［比較例５］
ナイロン６捲縮糸（２３ｔｅｘ、伸縮復元率３５％、フィラメント数６０本）を用いた以外は実施例４と同様にして丸編み地を作製し精練してカバークロスを作成した。このカバークロスにナイロン繊維用のＲＦＬ接着処理を行って接着処理したカバークロスを調製した。
【００６６】
得られた接着処理したカバークロスを用いた以外は実施例４と同様にして歯付けベルトを作製した。得られた歯付けベルトの耐久時間は３０時間と耐久性が劣っていた。
【００６７】
［実施例５］
ポリウレタン系スパンデックス１５．４ｔｅｘの３倍引き延ばし状態に、実施例１で作製したパラ系アラミド繊維（ＫＥＶＬＡＲ （Ｒ））製捲縮糸（４４ｔｅｘ、フィラメント数２６６本、伸縮復元率１０％）を巻き付けてシングルカバードヤーン（ＳＣＹ）を作製した。得られたシングルカバードヤーンを用いてゲージ数１６の丸編み機で編み組織インターロックの丸編み地を編み上げ、精練してカバークロスとし、実施例４と同様に接着処理を施し、接着処理したカバークロスを得た。この接着処理したカバークロスを用いた以外、実施例４とまったく同様にして歯付きベルトを作製した。カバークロスの伸縮性が高いので、カバークロスと歯付きベルトの噛み合わせ部との密着性は良好であった。また、得られた歯付きベルトの耐久時間は１９０時間と耐久性良好であった。
【００６８】
これらの試験結果を表３に示す。
【００６９】
【表３】

【００７０】
【発明の効果】
本発明の歯付きベルト用カバークロスは、歯付きベルト用に要求される伸縮性を有し、耐熱性が良好であり、しかも、毛羽立ちし難い等の優れた特性を有するので、耐熱性、耐久性に優れた歯付きベルトを製造することができ、しかも、表面形状の良好な歯付きベルトとすることができる。
【図面の簡単な説明】
【図１】歯付きベルトの一実施態様におけるベルト長手方向の断面図である。
【図２】実施例での歯付きベルトの耐久時間の測定における耐久性試験装置を示す概略図である。
【符号の説明】
１ 補強用芯線、 ２ ベルト本体、 ３ 歯部、 ４ 歯底部、 ５カバークロス、 １１〜１３ 従動プーリ、 １４ 駆動プーリ、 １５ オートテンショナー[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cover cloth used in an elastomer toothed belt whose transmission surface is covered with a fiber material.
[0002]
[Prior art]
The toothed belt is manufactured by providing a large number of teeth along a belt longitudinal direction on a belt body in which a core wire is embedded, and covering the tooth surface and the tooth bottom with a cover cloth made of a woven or knitted fabric. . The belt body is made of urethane resin or an elastomer or rubber such as urethane rubber, chloroprene rubber, or hydrogenated nitrile rubber. The cover cloth is woven using a non-crimped nylon yarn as the warp yarn arranged in the width direction of the belt body and a crimped nylon yarn as the weft yarn arranged along the longitudinal direction of the belt body. Generally, a woven fabric is used. By arranging the elastic crimped yarn along the longitudinal direction of the belt in this manner, the tooth surface and the tooth bottom forming the irregularities in the longitudinal direction of the belt can be easily covered by the cover cloth during belt molding. Coated.
[0003]
General-purpose thermoplastic synthetic fibers such as nylon fibers and polyester fibers widely used as clothing and industrial materials melt at about 250 ° C. Therefore, at a temperature lower than the melting temperature, for example, 160 ° C., the strength is reduced and the device cannot be used. The limiting oxygen index of nylon fiber, which is a general-purpose thermoplastic synthetic fiber, is 21 and the limiting oxygen index of polyester fiber is 21, which is a material that continues burning in air.
[0004]
On the other hand, heat-resistant and high-performance fibers such as aramid fibers, wholly aromatic polyester fibers, and polyparaphenylene benzobisoxazole fibers do not melt at about 250 ° C. and have a high decomposition temperature of about 500 ° C. Therefore, the strength does not decrease even at around 160 ° C., and it is used as a heat-resistant rubber reinforcing material for a core yarn of a toothed belt, a reinforcing yarn of a hose, and the like. Since it has a limiting oxygen index of 25 or more and does not easily burn in air, it is also used in firefighting clothes and firefighting gloves.
[0005]
In particular, among the aramid fibers, para-aramid fibers are used for core yarns of toothed belts and tire reinforcement cords because of their high heat resistance and high tensile strength. For example, a typical para-aramid fiber, KEVLAR (polyparaphenylene terephthalamide fiber) manufactured by Toray Dupont Co., Ltd. has a tensile strength of 2.03 (N / tex), and is a polyester fiber which is a general-purpose fiber. It has several times the tensile strength as compared with 0.4 (N / tex) of nylon and nylon fibers.
[0006]
By the way, the toothed belt is used for driving a fuel pump of an automobile or the like, and in recent years, the engine room has been designed to have a higher temperature than before in order to improve the fuel efficiency of the automobile. For this reason, the toothed belt operates under high heat and high load, and higher durability is required for the cover cloth that directly contacts the pulley.
[0007]
Therefore, various proposals using heat-resistant aramid fibers have been made. For example, in Patent Literature 1, as a weft arranged in a belt longitudinal direction of a cover cloth, a mixed yarn of an aromatic polyamide spun yarn and a urethane elastic yarn is used, and a single yarn of 10 to 50 denier is used as a warp yarn. The use of fibers is disclosed. Patent Literature 2 discloses that a weft yarn is a covering yarn obtained by winding an aramid-based spinning spun yarn as a sheath yarn on a core yarn of a nylon woolly yarn.
[0008]
[Patent Document 1] JP-A-4-8948
[Patent Document 2] Japanese Patent Application Laid-Open No. Hei 9-119483
[0009]
[Problems to be solved by the invention]
These proposals attempt to improve the elasticity of the cover cloth by combining spun yarns of aramid fiber and stretched spun yarns with elastic urethane elastic yarns and nylon woolly yarns. The use of aramid fibers without fibers did not provide sufficient elasticity, resulting in inadequate adhesion to the teeth and the bottom of the teeth, and had a problem as a cover cloth for a toothed belt. In other words, conventional heat-resistant and high-performance fiber filaments having no stretchability and woven knits made of spun yarn of heat-resistant and high-performance fibers have insufficient stretchability, and have been problematic for use as a cover cloth for a toothed belt.
[0010]
Therefore, the present invention solves these problems of the prior art, and a cover cloth capable of manufacturing a toothed belt having high durability under a high-temperature environment and high durability against abrasion and heat generation due to friction between a pulley and a tooth surface. The main purpose is to provide.
[0011]
[Means for Solving the Problems]
The present inventors have conducted intensive studies to achieve the above object, and as a result, by using a heat-resistant and high-performance fiber in the form of a crimped yarn having a specific expansion / recovery ratio and without deterioration in quality due to heating, the above object has been achieved. The inventors have found out what can be achieved, and have accomplished the present invention.
[0012]
That is, the present invention is specified by the following items.
(1) A cover used in a toothed belt in which a reinforcing core wire is buried in the longitudinal direction of the belt, a plurality of teeth are arranged at a predetermined pitch in the longitudinal direction of the belt, and the surface of the teeth is covered with a cover cloth. A cover cloth for a toothed belt, wherein the cover cloth is knitted and woven using a heat-resistant and high-performance fiber filament crimped yarn, which has a stretch recovery ratio of 4 to 78% as measured based on JIS K 1013.
(2) The heat-resistant and high-performance fiber filament is a filament having a limiting oxygen index of 25 or more measured according to JIS K 7201 and a thermal decomposition temperature of 400 ° C. or more measured according to JIS K 7120. 2. The cover cloth for a toothed belt according to 1.
(3) The cover cloth for a toothed belt according to the above (1) or (2), wherein the heat-resistant and high-performance fibers are aramid fibers.
(4) The cover cloth for a toothed belt according to the above (3), wherein the aramid fiber is a para-aramid fiber.
(5) The cover cloth for a toothed belt as described in (4) above, wherein the para-aramid fiber is a polyparaphenylene terephthalamide fiber.
(6) The cover cloth for a toothed belt according to any one of (1) to (5) above, wherein the cover cloth is a woven fabric, and at least a heat-resistant and high-performance fiber filament crimped yarn is used as a weft material.
(7) The cover cloth for a toothed belt according to any one of (1) to (5) above, wherein the cover cloth is a knit.
(8) A toothed belt in which a surface of a tooth portion is covered by the cover cloth according to any one of the above (1) to (7).
[0013]
In the toothed belt cover cloth of the present invention, as described above, the crimped yarn of the specific bulky and stretchable heat-resistant and high-performance fiber is used in combination with other fiber materials as necessary. Compared to a cover cloth combining a heat-resistant and high-performance filament which is a non-crimped yarn with a spun yarn such as aramid fiber and a stretchable spandex, the cover cloth is excellent in elasticity and can be closely adhered to a tooth portion and a tooth bottom portion. That is, the present invention uses a crimped yarn of a specific heat-resistant and high-performance fiber as a material for the cover cloth, thereby imparting elasticity to the woven and knitted fabric of the heat-resistant and high-performance fiber, and is used as a cover cloth for a toothed belt. This is what we made possible.
[0014]
Also, spun yarn has a short fiber end protruding into the yarn surface and has a fluff shape.Therefore, there is a problem that a cover cloth made of a spun yarn of heat-resistant and high-performance fiber is liable to fall off due to friction during use, In the cover cloth of the present invention, since a crimped yarn of heat-resistant and high-performance fiber composed of long fibers is used, there is no fuzz on the yarn surface, and even if it is subjected to friction or the like during transmission of the toothed belt, it is possible to form a single fiber. The fluff which is the cut end is hardly generated, and the single fiber fluff does not fall off, so that the durability is improved.
[0015]
According to the present invention, by using crimped yarn of heat-resistant and high-performance fiber as a material for the cover cloth, stretchability is imparted to the woven and knitted fabric of the heat-resistant and high-performance fiber, and the belt can be used as a cover cloth for a toothed belt.
In addition, the heat resistance is improved as compared with the conventional toothed belt using a cover cloth made of a general-purpose fiber material, so that the durability of the belt is improved.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
In the toothed belt to which the cover cloth of the present invention is applied, a reinforcing core wire is buried in the belt longitudinal direction, a plurality of teeth are arranged at a predetermined pitch in the belt longitudinal direction, and the surface of the tooth is covered with the cover cloth. Is a toothed belt having a structure covered with, for example, the structure shown in FIG. FIG. 1 is a sectional view of the toothed belt in the belt longitudinal direction. In FIG. 1, on one surface of a belt body 2 in which a core wire 1 is embedded in rubber or an elastomer, a large number of teeth 3 are integrally provided so as to protrude along the longitudinal direction thereof. A cover cloth 5 is arranged on the tooth bottom 4.
[0017]
As the core wire arranged on the belt pitch line, for example, a rope-shaped fiber cord made of heat-resistant and high-performance fiber such as glass fiber or para-aromatic polyamide fiber, carbon fiber, or the like is used.
[0018]
The cover cloth used for the toothed belt needs to have elasticity particularly in the lateral direction in order to make close contact with the teeth 3 and the bottom 4. The cover cloth according to the present invention is a fabric manufactured by knitting using a bulky and elastic crimped yarn of heat-resistant and high-performance fiber in combination with other fibers as necessary. The cloth may be a woven fabric or a knitted fabric such as circular knit, warp knit, or weft knit. In the case of a woven fabric, a crimped yarn of a heat-resistant high-performance fiber is used at least as a weft material.
[0019]
When this cover cloth is used in the manufacturing process of the toothed belt, the adhesive treatment is generally performed in the order of epoxy-based adhesive treatment, RFL treatment, and solvent-based adhesive treatment. Depending on the type of rubber or elastomer, these treatment agents may be used. Adjustment of the formulation is made. Depending on the type of rubber or elastomer, only the solvent-based adhesive treatment may be performed.
Also, depending on the type of rubber or elastomer and the use of the toothed belt, the adhesive treatment may not be performed.
[0020]
As the elastomer, an elastomer or rubber such as urethane resin or urethane rubber, chloroprene rubber, or hydrogenated nitrile rubber is used.
[0021]
As the heat-resistant and high-performance fiber used in the present invention, a fiber having a flame retardancy of about 25 or more and a thermal decomposition temperature of about 400 ° C. or more by a differential scanning calorimeter is a toothed belt. It is preferable for obtaining heat resistance and durability. Examples thereof include aramid fiber, wholly aromatic polyester fiber (eg, Kuraray Co., Ltd., trade name Vectran), polyparaphenylene benzobisoxazole fiber (eg, Toyobo Co., Ltd., trade name Zylon), polybenzimidazole fiber, polyamide Examples include imide fibers (for example, manufactured by Rhone Poulin Co., Ltd., trade name: Kermel), and polyimide fibers. Aramid fibers include meta-aramid fibers and para-aramid fibers. As the meta-aramid fiber, for example, a meta-based wholly aromatic polyamide fiber such as polymetaphenylene isophthalamide fiber (manufactured by DuPont, trade name: Nomex) can be mentioned. Examples of the para-aramid fiber include polyparaphenylene terephthalamide fiber (manufactured by Du Pont-Toray Co., Ltd., trade name KEVLAR®) and copolyparaphenylene-3,4′-diphenylether terephthalamide fiber (manufactured by Teijin Limited, And para-type wholly aromatic polyamide fibers such as trade name Technora).
[0022]
The crimped yarn of the heat-resistant and high-performance fiber used in the present invention may be composed of one kind of the heat-resistant and high-performance fiber, or may be composed of two or more arbitrary heat-resistant and high-performance fibers. Further, it can also be used as a composite yarn obtained by blending or twisting with other known fibers such as polyester, nylon and polyvinyl alcohol-based fibers.
[0023]
Aramid fibers are suitable for the cover cloth of the present invention since a high elasticity recovery ratio is obtained and the elasticity is high. Also, para-aramid fibers are suitable because they have a high tensile strength in addition to heat resistance, can withstand high loads, and provide a cover cloth with excellent durability. Among them, polyparaphenylene terephthalamide fiber is most suitable because of its high heat resistance.
[0024]
The heat-resistant and high-performance fiber filament crimped yarn can be obtained, for example, by the following method. A twist having a twist coefficient K represented by the following formula of 5,000 to 11,000 is added to the heat-resistant and high-performance fiber yarn, and then a high-temperature and high-pressure steam treatment or a high-temperature and high-pressure water treatment at a temperature of 130 to 250 ° C. is performed. And twisting the fixed twisted yarn in the opposite direction to that described above.
K = t × D ^1/2 [However, t represents the number of twists (times / m), and D represents the fineness (tex). ]
[0025]
When using saturated steam as high-temperature and high-pressure steam, the pressure at the time of the treatment is uniquely determined physicochemically from the above temperature conditions. The value of the saturated steam pressure at the lower limit temperature of 130 ° C. is 2.70 × 10 ⁵ Pa, and the value of the saturated steam pressure at the upper limit temperature of 250 ° C. are 38.97 × 10 ⁵ It corresponds to Pa.
[0026]
The heat-resistant and high-performance fiber filament crimped yarn used in the present invention has an expansion / contraction restoration rate of 4 to 78%. If it is less than 4%, practical stretchability cannot be obtained as a cover cloth, and if it exceeds 78%, the surface of the cover cloth obtained by weaving or knitting becomes extremely uneven, so that the cover cloth for a toothed belt is Not suitable. The expansion / contraction restoration rate of the heat-resistant and high-performance fiber filament crimped yarn is preferably 5 to 70%, more preferably 6 to 50%.
[0027]
The single yarn fineness of the heat-resistant and high-performance fiber filament crimped yarn used in the present invention is about 0.02 to 1 tex, preferably about 0.05 to 0.6 tex, and more preferably about 0.08 to 0.5 tex. The degree is preferable from the viewpoint of the flexibility of the crimped yarn of the heat-resistant and high-performance fiber and the ease of manufacturing the crimped yarn of the heat-resistant and high-performance fiber according to the present invention.
[0028]
The total fineness of the heat-resistant and high-performance fiber filament crimped yarn used in the present invention is not limited as long as the yarn can be processed into a twisted yarn or a knitted fabric. In consideration of the ease with which the distance is adjusted, it is about 3 to 400 tex, preferably 5 to 100 tex, and more preferably 7.5 to 50 tex.
[0029]
The fineness is represented by tex specified in JIS L 0101 (1999). For example, 1 tex indicates that a fiber having a length of 1000 m has a mass of 1 g, and 10 tex indicates that a fiber having a length of 1000 m has a mass of 10 g. The larger the value represented by tex, the thicker the fiber.
[0030]
By using the heat-resistant and high-performance fiber crimped yarn as at least the weft of the cover cloth, a heat-resistant and high-performance fiber cover cloth having excellent heat resistance and abrasion resistance as compared with a conventional cover cloth (for example, made of nylon) can be obtained.
[0031]
Due to the belt manufacturing method, a woven fabric or knit that stretches with low tension is required to make the cover cloth adhere to the teeth of the toothed belt. A conventional woven fabric or knitted fabric made of a heat-resistant functional fiber filament yarn without crimp or a spun yarn of a heat-resistant functional fiber could not secure sufficient elasticity.
[0032]
In addition, a so-called covered yarn in which a heat-resistant high-performance fiber crimped yarn is wound around an elastic yarn such as a urethane-based material that has been stretched about three times is used. A cover cloth that easily adheres to the belt teeth can be obtained. Furthermore, the knitted fabric using the covered yarn is easily stretched because the stretchability of the covered yarn itself acts in addition to its structural elongation, and is suitable as a cover cloth for a toothed belt.
[0033]
By using the heat-resistant functional fiber crimped yarn, it has become possible to produce a heat-resistant functional fiber woven fabric or knitted fabric having lower tension and elasticity. In addition, the cover cloth of the present invention has made it possible to apply the heat-resistant functional fiber to a resin belt such as a urethane resin having a low extrusion pressure.
[0034]
【Example】
Hereinafter, the present invention will be specifically described based on examples.
The following methods were used to evaluate each property.
[0035]
Limit oxygen index: JIS K 7201: 1999 Measured by a combustion test method for polymer materials by the oxygen index method.
[0036]
Thermal decomposition temperature: JIS K 7120: 1987 Measured by a thermogravimetric method for plastics.
[0037]
Stretch recovery rate: Measured according to JIS L 1013: 1999 Chemical fiber filament test method 8.12 Stretch recovery rate. Preparation of the sample before measurement was performed as follows. While keeping the measurement sample in a skein shape and wrapped in gauze, a warm water treatment was performed at 90 ° C. for 20 minutes, and the sample was naturally dried at room temperature.
[0038]
Fineness: JIS L 1013: 1999 Positive fineness was measured according to Chemical Fiber Filament Yarn Test Method 8.3.
[0039]
Tensile strength: Measured according to JIS L 1013: 1999 Chemical Fiber Filament Yarn Test Method 8.5.1. However, it was measured by applying a twist having a twist coefficient K = 1000 before the measurement so as to eliminate the disorder of the single fibers and apply stress to each of the single fibers constituting the yarn.
[0040]
Belt durability: Measured using a durability test apparatus shown in FIG. The toothed belt was wrapped around the driven pulleys 11 to 13, the driving pulley 14, and the auto tensioner 15 as shown in FIG. 2, and the driving pulley 15 was rotated at a speed of 4000 (times / minute) in an environment of 100 ° C. . The endurance time was defined as the point at which the belt function could no longer be fulfilled due to cracks at the base of the teeth or missing teeth.
[0041]
[Example 1]
A crimped para-aramid fiber produced as follows was used as the weft of the cover cloth.
[0042]
Toray-Dupont stock having a limiting oxygen index of 29, a thermal decomposition point of 537 ° C., a tensile strength of 2.03 N / tex, a tensile elasticity of 49.9 N / tex, and a fineness of 44 tex in which 266 single yarns having a fineness of 0.167 tex are bundled. Using a company-made polyparaphenylene terephthalamide fiber filament yarn (trade name: KEVLAR®), a first twist of 1150 (twice / m), that is, a twist coefficient K = 7628, is added to the yarn by a double twister. After that, heat treatment with saturated steam at 200 ° C. was performed for 20 minutes. Next, a second twist is applied by the twisting machine in a direction opposite to the first twist, and untwisted until the number of twists becomes substantially zero, to obtain a crimped para-aramid fiber having a 10% elasticity recovery ratio. Was.
[0043]
Using a nylon 6 filament yarn (23 tex, 60 filaments) having a tensile strength of 5 (N / tex) as a warp yarn and the para-aramid fiber crimped yarn as a weft yarn, weaving a 2/2 twill woven fabric. Then, scouring was performed by a conventional method at a scouring bath temperature of 95 ° C. to obtain a cover cloth having a warp yarn density of 90 (lines / 5 cm) and a weft yarn density of 80 (lines / 5 cm). This cover cloth was subjected to an epoxy treatment, and then subjected to an RFL bonding treatment to prepare a cover cloth that was subjected to an adhesion treatment.
[0044]
In addition, a belt core adjusted as follows was used.
Three ECG150 glass fibers were aligned, treated with a resorcinol-formalin-latex solution (RFL solution), air-dried, and then heat-treated at 280 ° C. for 1.5 minutes. Eleven small ropes prepared by plying and twisting at a ratio are prepared, and the plying is performed 8 times / 10 cm in the Z direction, and the plying is S direction in the Z direction. And twisted.
[0045]
Using the obtained cover cloth which has been subjected to the adhesive treatment, the weft thread is formed into an endless cylindrical shape having a circumferential direction, and set in a mold having a tooth profile, and S-twisted and Z-twisted core wires are alternately arranged on the cover cloth. Then, a rolled sheet made of NBR was further wound from above, followed by pressurization and vulcanization to produce a sleeve-shaped molded product. By cutting this into a predetermined width, the core wire is spirally wound in the circumferential direction of the belt at a pitch of 1.45 mm, and has a tooth width of 19.1 mm having a tooth portion having 163 teeth and a tooth pitch of 3 mm. Got the belt.
[0046]
The endurance time of the toothed belt thus obtained was 180 hours, and the durability was good.
[0047]
[Example 2]
Kevlar (R) filament yarn (22 tex, 133 filaments) is used for the warp yarn, and the crimped yarn (44 tex, expansion / contraction recovery rate 10%) made of para-aramid fiber (KEVLAR (R)) produced in Example 1 is used as the weft yarn. , A weave of 2/2 twill was woven and refined to form a cover cloth having a warp density of 90 (lines / 5 cm) and a weft yarn density of 80 (lines / 5 cm). This cover cloth was subjected to an epoxy treatment in the same manner as in Example 1, and then subjected to an RFL adhesion treatment to prepare a cover cloth that was subjected to an adhesion treatment.
[0048]
A toothed belt was produced in exactly the same manner as in Example 1, except that the obtained adhesive-treated cover cloth was used. The endurance time of the obtained toothed belt was 203 hours, and the durability was good.
[0049]
[Example 3]
Nylon 6 filament yarn (23 tex, 60 filaments) was used for the warp, and the para-aramid fiber (KEVLAR®) produced in Example 1 was stretched in a stretch state of 3 times stretch of polyurethane spandex 15.4 tex. Using a single covered yarn (SCY) produced by winding a crimped yarn (44 tex, elastic recovery ratio 10%) as a weft, weaving and scouring a woven fabric having a fabric structure of 2/2 twill, a warp density of 90 (lines / 5 cm) and a cover cloth having a weft yarn density of 80 (lines / 5 cm). This cover cloth was subjected to an epoxy treatment in the same manner as in Example 1, and then subjected to an RFL adhesion treatment to prepare a cover cloth that was subjected to an adhesion treatment. .
[0050]
A toothed belt was produced in exactly the same manner as in Example 1 except that the obtained bonded cover cloth was used. The endurance time of the obtained toothed belt was 210 hours, which was good.
[0051]
[Comparative Example 1]
Nylon 6 filament yarn (23 tex, number of filaments: 60) is used for the warp yarn, and nylon 6 crimped yarn (elasticity recovery ratio: 35%), 23 tex double ply yarn (2 ply yarn) is used for the weft yarn, and the warp yarn density is 90 ( Book / 5 cm), a weft yarn density of 80 (book / 5 cm), and a woven fabric having a fabric structure of 2/2 twill were woven into a cover cloth. The cover cloth was subjected to an RFL bonding treatment for nylon fibers to prepare a cover cloth that was bonded.
[0052]
A toothed belt was produced in exactly the same manner as in Example 1, except that the obtained adhesive-treated cover cloth was used. The endurance time of the obtained toothed belt was inferior at 35 hours.
[0053]
[Comparative Example 2]
After 1150 (twist / m), that is, the first twist having a twist coefficient of K = 7628, was added to the KEVLAR (R) 44tex filament yarn with a double twister, a heat treatment with saturated steam at 130 ° C. was performed for 20 minutes. Next, a second twist is applied by the above twisting machine in a direction opposite to the first twist and untwisted until the number of twists becomes almost 0, to obtain a crimped para-aramid fiber with a 3% elasticity recovery ratio. Was.
[0054]
Except for using the obtained KEVLAR (R) fiber crimped yarn having a 3% elasticity recovery ratio as the weft, an adhesive-treated cover cloth having exactly the same configuration as in Example 1 was produced. A belt with a belt was prepared. The resulting toothed belt had insufficient adhesion to the teeth and the tooth bottom because the cover cloth had little stretchability. The durability time of the toothed belt was 30 hours, which was shorter than that of Example 1.
[0055]
[Comparative Example 3]
After 1300 (twist / m), that is, the first twist having a twist coefficient of K = 8660, was added to the KEVLAR (R) 44tex filament yarn with a double twister, a heat treatment with saturated steam at 220 ° C. was performed for 20 minutes. Next, a second twist is given by the twisting machine in a direction opposite to the first twist, and untwisted until the number of twists becomes almost 0, to obtain a crimped para-aramid fiber having an elasticity recovery ratio of 80%. Was.
[0056]
A cover cloth having exactly the same configuration as that of Example 1 was produced except that the obtained KEVLAR (R) fiber crimped yarn having a recovery rate of 80% was used as the weft yarn. Since the obtained cover cloth had too high elasticity, the unevenness of the cover cloth itself was large, and it was difficult to use it as a cover cloth for a toothed belt.
[0057]
[Comparative Example 4]
A single-covered yarn is wound by winding a para-aramid fiber (KEVLAR (R)) crimped yarn (44 tex, elasticity recovery ratio: 3%) produced in Comparative Example 1 in a stretched state with a polyurethane spandex 15.4 tex 3 times stretch. SCY). The obtained SCY is a single-covered yarn having many defects in which the KEVLAR (R) crimped yarn is too low in expansion / contraction restoration rate, and thus the winding around the spandex is uneven and the KEVLAR (R) crimped yarn protrudes in a snal shape. Met.
[0058]
Nylon 6 filament yarn (23 tex, 60 filaments) is used for the warp yarn, and the SCY is used for the weft yarn, and weaving and scouring a woven fabric having a fabric structure of 2/2 twill, the warp yarn density is 90 (lines / 5 cm), the weft yarn density 80 (books / 5 cm) cover cloth was obtained. Since the obtained cover cloth was a non-uniform surface woven fabric in which snare-like KEVLAR (R) crimped yarn protruded from the surface, it was difficult to use it as a cover cloth for a toothed belt.
[0059]
Tables 1 and 2 show these results.
[0060]
[Table 1]

[0061]
[Table 2]

[0062]
[Example 4]
Para-aramid fiber KEVLAR (R) A para-aramid fiber KEVLAR produced in the same manner as in Example 1, except that a twist of 1662 (twist / m), that is, a twist coefficient K = 7800 was added to a 22-tex yarn with a double twister. (R) Using a 22 knit crimped yarn (133 filaments, expansion / contraction restoration rate: 8%), a circular knitted fabric of knitting structure interlock (Smooth) is knitted by a circular knitting machine of 16 gauges, scoured and covered with a cover cloth. did. This cover cloth was subjected to an epoxy treatment in the same manner as in Example 1, and then subjected to an RFL adhesion treatment to prepare a cover cloth that was subjected to an adhesion treatment.
[0063]
In addition, a belt core adjusted as follows was used.
Three ECG150 glass fibers were aligned, treated with a resorcinol-formalin-latex solution (RFL solution), air-dried, and then heat-treated at 280 ° C. for 1.5 minutes. Eleven small ropes prepared by plying and twisting at a ratio are prepared, and the plying is performed 8 times / 10 cm in the Z direction, and the plying is S direction in the Z direction. And twisted.
[0064]
Using the obtained adhesive-treated cover cloth and core wire, a urethane resin toothed belt having a belt width of 19.1 mm, a fraction of 163 and a tooth pitch of 8 mm was produced in the same manner as in Example 1. The endurance time of the toothed belt thus obtained was 140 hours, and the durability was good.
[0065]
[Comparative Example 5]
A circular knitted fabric was prepared and scoured in the same manner as in Example 4 except that a nylon 6 crimped yarn (23 tex, elastic recovery 35%, number of filaments 60) was used, and a cover cloth was prepared. The cover cloth was subjected to an RFL bonding treatment for nylon fibers to prepare a cover cloth that was bonded.
[0066]
A toothed belt was prepared in the same manner as in Example 4 except that the obtained adhesive-treated cover cloth was used. The endurance time of the obtained toothed belt was 30 hours, which was inferior in durability.
[0067]
[Example 5]
A para-aramid fiber (KEVLAR (R)) crimped yarn (44 tex, 266 filaments, 10% expansion / recovery rate) wound in a three-fold stretched state of polyurethane spandex 15.4 tex was used. A single covered yarn (SCY) was made. Using the obtained single covered yarn, a circular knitted fabric having a knitted structure interlock was knitted with a circular knitting machine having a gauge of 16 and scoured to obtain a cover cloth. Got. A toothed belt was produced in exactly the same manner as in Example 4 except that this cover cloth subjected to the adhesion treatment was used. Since the elasticity of the cover cloth was high, the adhesion between the cover cloth and the meshing portion of the toothed belt was good. Further, the durability of the obtained toothed belt was 190 hours, which was excellent in durability.
[0068]
Table 3 shows the test results.
[0069]
[Table 3]

[0070]
【The invention's effect】
The cover cloth for a toothed belt of the present invention has the elasticity required for a toothed belt, has good heat resistance, and has excellent properties such as difficulty in fluffing. A toothed belt having excellent properties can be manufactured, and a toothed belt having a good surface shape can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an embodiment of a toothed belt in a belt longitudinal direction.
FIG. 2 is a schematic diagram showing a durability test apparatus for measuring the durability time of a toothed belt in an example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Reinforcing core wire, 2 Belt body, 3 Teeth, 4 Teeth bottom, 5 Cover cloth, 11-13 Followed pulley, 14 Drive pulley, 15 Auto tensioner

Claims (8)

A cover cloth used in a toothed belt in which a reinforcing core wire is buried in the longitudinal direction of the belt, a plurality of teeth are arranged at a predetermined pitch in the longitudinal direction of the belt, and the surface of the teeth is covered with the cover cloth. And a cover cloth for a toothed belt, wherein the cover cloth is knitted and woven using a heat-resistant and high-performance fiber filament crimped yarn having an elasticity recovery ratio measured based on JIS K 1013 in the range of 4 to 78%. . The heat-resistant and high-performance fiber filament is a filament having a limiting oxygen index of 25 or more measured based on JIS K 7201 and a thermal decomposition temperature of 400 ° C. or more measured based on JIS K 7120. The toothed belt cover cloth according to claim 1. 3. The cover cloth for a toothed belt according to claim 1, wherein the heat-resistant and high-performance fiber is an aramid fiber. The cover cloth for a toothed belt according to claim 3, wherein the aramid fiber is a para-aramid fiber. The cover cloth for a toothed belt according to claim 4, wherein the para-aramid fiber is a polyparaphenylene terephthalamide fiber. The cover cloth for a toothed belt according to any one of claims 1 to 5, wherein the cover cloth is a woven fabric, and at least a heat-resistant and high-performance fiber filament crimped yarn is used as a weft material. The cover cloth for a toothed belt according to any one of claims 1 to 5, wherein the cover cloth is a knit. A toothed belt, wherein a surface of a tooth portion is covered by the cover cloth according to any one of claims 1 to 7.

Images