JPH0526298A - Belt for industrial use - Google Patents

Abstract

PURPOSE:To improve bending fatigue resistance by a method wherein a reinforcing substance formed of fibers embedded in the belt body of a toothed belt is formed of a cord braided rope braided in a cylindrical shape by using the odd number of threads being three or more and having a hollow part. CONSTITUTION:A reinforcing substance 2 formed of fibers is embedded in a back rubber layer 1 of a toothed belt body A. The reinforcing substance 2 is formed of a plurality of cord braided ropes 7 wherein the odd number of threads 6 being three or more is braided in a cylindrical shape and a hollow part 8 is formed therein. Inorganic fibers and organic fibers are used for the thread 6 and properly selected according to demand performance of the toothed belt A. The number of the threads 6 and a thread count are an odd number being 3-9, so that the size of the hollow part 8 is reduced, and size stability is prevented from lowering owing to flattening phenomenon during expansion. A total denier number and a monofilament denier number of the thread 6 are also properly selected according to demanded performance of the belt A, an uniform stress is applied on the monofilament, and bending fatigue resistance is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial belt,
Particularly, it relates to improvement of a reinforcing body (tensile strength body) embedded in a belt body.

[0002]

2. Description of the Related Art Conventionally, industrial belts such as transmission belts such as toothed belts, V-belts, flat belts and ribbed belts, and conveyor belts have high strength, high elastic modulus, high dimensional stability and high strength. Since properties such as adhesiveness are required, reinforcing cords made of fibers and a reinforcing body such as a cloth-like material are embedded in the belt body to satisfy these properties. As the reinforcing body, a twisted yarn formed by twisting a plurality of yarns is generally used, and the type thereof can be classified into a plied yarn, a single twisted yarn, a rung twisted yarn, and the like depending on the twisting method. In the present situation, among the above-mentioned twisted yarns, the plied yarns are most often used as the reinforcing body of the rubber product.

However, in the industrial belt in which the reinforcement is made of the plied yarn, a portion where the monofilaments strongly contact each other at a deep angle occurs inside the plied yarn, so that the strong contact portion causes early wear, breakage or breakage. There was a problem that the strength was lowered and the flex fatigue resistance deteriorated.

Therefore, as an industrial belt having the above-mentioned problems (flexing fatigue resistance) improved, a belt composed of a single twisted yarn or a rung twisted yarn as a reinforcement has been proposed (Japanese Patent Laid-Open No. 59-19744). reference).

[0005]

However, in the industrial belt in which the reinforcing body is composed of the single twisted yarn or the rung twisted yarn as described above, due to its structure, the stretching and dipping treatment is performed as compared with the case where the reinforcing body is constituted by the plied yarns. After that, the tensile elastic modulus is likely to be small, and the dimensional stability is likely to be deteriorated.

Further, since the above single twisted yarn and rung twisted yarn are twisted only in one direction, untwisting is likely to occur, and fraying is likely to occur at the ends, which makes it difficult to process. Further, during belt processing, There is also a problem that flakes are likely to occur on the cut surface.

Further, in the industrial belt using the single twisted yarn or the rung twisted yarn as the reinforcing member, since the single twisted yarn or the like has the direction of twisting as described above, one side is deviated in one direction during running. There is also a problem that uneven wear is likely to occur. On the other hand, as disclosed in, for example, Japanese Unexamined Patent Publication No. 56-103008, by using a reinforcing body in which uni-twisted yarns of S twist and Z twist are alternately arranged,
There has been proposed a conveyor belt designed to eliminate uneven wear. However, in this case, since two cords (single twisted yarn) are arranged in parallel and spirally in the belt,
There are a total of 4 cord cut surfaces on the left and right belt end faces, which reduces the cord strength utilization rate and is difficult to use.

The present invention has been made in view of the above points, and an object of the present invention is to form a reinforcing body by using a traditional braided braid instead of the twisted yarn, so that the bending fatigue resistance and the dimension are improved. Another object of the present invention is to provide an industrial belt having excellent stability and long life.

[0009]

In order to achieve the above-mentioned object, a first solution means of the present invention is an industrial belt in which a reinforcing body made of fibers is embedded in a belt body, and three reinforcing bodies are provided. It is configured by a round braid having a hollow portion which is assembled in a cylindrical shape by the above-mentioned odd number of yarns.

A second solution means of the present invention is that, in the first solution means, the round braid is formed into a cylindrical shape by an odd number of threads of 3 or more and 9 or less.

A third solving means of the present invention is the same as in the first solving means, wherein the round braided braid is set from left-handed and right-handed yarns in which the twisting directions are set to S twist and Z twist in opposite directions. It is configured by assembling into a cylindrical shape with an odd number of three or more yarns.

A fourth solution means of the present invention is that in the first solution means, the adhesive is uniformly impregnated from the surface to the inside of the round braid.

A fifth solution means of the present invention is that, in the first solution means, a core thread is provided in the hollow portion of the round braid.

A sixth solving means of the present invention is the fifth solving means, wherein the twisting coefficient of the core yarn is K = 350 or less.

[0015]

[Equation 2]

K: twist coefficient T: Number of twists per 10 cm D: Number of total denier Is set to.

[0017]

With the above structure, in the present invention according to claim 1, the reinforcing member made of fibers embedded in the belt main body is 3
Since it is composed of a round braid having a hollow portion formed in a cylindrical shape by an odd number of yarns of not less than two, uniform stress is exerted on the monofilaments constituting the yarn as a structural characteristic of the round braid. Therefore, bending fatigue resistance is significantly improved. In addition, the tensile elastic modulus after stretching and dipping is larger than that of a reinforcing body made of twisted yarn due to the structure of the round braid, and the dimensional stability of the industrial belt is improved. Furthermore, the unraveling of the end portion due to the untwisting in the single-twisted yarn, the rung-twisted yarn, or the like is eliminated, and the workability is improved, and further, the flare on the cut surface is less likely to occur during belt processing. Further, the directionality of twisting such as a single twisted yarn is eliminated, the industrial belt is stably run, the unevenness during running is eliminated, and uneven wear is prevented.

According to the second aspect of the present invention, since the round braided braid is formed into a cylindrical shape with an odd number of threads of 3 or more and 9 or less, the hollow portion becomes extremely small, The flatness phenomenon during stretching is restricted, and the dimensional stability of the industrial belt is significantly improved.

In the present invention according to claim 3, the round braided braid has an odd number of three or more consisting of left-handed and right-handed braided yarns in which the twisting directions are set in the opposite directions of S twist and Z twist. Since it is composed of yarns in a cylindrical shape,
The directionality of the driven yarn is canceled by the S twist and the Z twist, and the bending fatigue resistance is greatly improved.

According to the present invention of claim 4, when the round braided cord constituting the reinforcement is treated with an adhesive, the adhesive is uniformly impregnated from the surface to the inside of the braided braid.
Flexural strain due to uneven distribution of impregnation of the adhesive is prevented.

In the present invention according to claim 5, since the core thread is provided in the hollow portion of the round braided cord, the flattening phenomenon at the time of extension is restricted, and the dimensional stability of the rubber product is improved.

In the present invention according to claim 6, the twisting coefficient of the core yarn is K = 350 or less.

[0023]

[Equation 3]

K: Twisting coefficient T: Number of twists per 10 cm D: Since the number of total denier is set, the strength utilization factor and elastic modulus utilization factor of the reinforcing member of the industrial belt are improved by the twisting characteristics of the twisted yarn. Further, the structural characteristics of the round braided cord cover the deformation of the twisted yarn against external stress, and the dimensional stability of the industrial belt is improved.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) FIG. 3 shows a toothed belt A as an industrial belt according to the first embodiment of the present invention. The toothed belt A has a back rubber layer 1, a reinforcing member 2 made of fibers embedded in the back rubber layer 1, and the back rubber layer 1 on one side of the back rubber layer 1 (the lower side in FIG. 3). A belt main body 4 including a tooth portion rubber layer 3 integrally formed of a rubber material is provided, and a tooth cloth 5 is provided on the surface side of the tooth portion rubber layer 3 of the belt main body 4.
Are covered in one piece.

As a feature of the present invention, the reinforcing body 2 has an odd number of three or more (five in this embodiment) yarns 6, 6 as shown in enlarged detail in FIGS. , And ... are composed of a plurality of round braided braids 7, 7 having a hollow portion 8 assembled in a cylindrical shape.

As the type of the yarn 6, inorganic fibers, organic fibers, metal fibers and the like are used, and further, spun yarns composed of long fibers and short fibers or mixed yarns thereof may be used. In short, it may be appropriately selected according to the required performance of the toothed belt A.

The number of yarns 6 forming the round striking braid 7 may be an odd number of 3 or more, but is preferably an odd number of 3 or more and 9 or less. The upper limit of the number of driving is set to 9 in order to make the hollow portion 8 extremely small, and when 9 is exceeded, a relatively large hollow portion 8 is formed and dimensional stability is achieved due to the flattening phenomenon during extension. This is because the sex is reduced. Furthermore, the total number of denier of the yarn 6 and the number of monofilament denier may be appropriately selected according to the required performance of the toothed belt A.

Further, the round braided braid 7 assembled as described above is, for example, an epoxy resin, an isocyanate compound, an ethylene urea compound and resorcinol formalin latex (RFL) before being embedded in the back rubber layer 1.
Adhesive treatment and stretching treatment are performed by a combination of adhesives composed of the above. As the adhesive treatment method, the dipping method is preferable because it is necessary to uniformly impregnate the adhesive from the surface of the braided braid 7 constituting the reinforcing body 2 to the inside thereof.

Next, a bending fatigue test of the toothed belt A according to the present Example I was carried out under the following conditions and procedures along with Comparative Examples I and II, and the results are shown in Table 1 below. The numerical values in Table 1 represent the belt strength maintenance rate.

[Structure of Toothed Belt A of this Embodiment I] As a round braid 7 constituting the reinforcing body 2, Kevlar (trade name, manufactured by DuPont) 1500 de rounded braces (total denier number: 7500 de) was used. The round braided string 7 is first dipped in an adhesive of an isocyanate compound to form a subcoat layer, and then dipped in an adhesive of resorcinol-formalin latex (RFL) to form a second coat layer, and thereafter. Dip in CR glue rubber to form topcoat layer, then 1g / de
Stretching treatment was performed with the tension. The plurality of round striking braids 7, 7, ...
Spiral lined on top of each of the above round braids 7
After the tooth rubber layer 3 made of CR rubber is formed so as to be embedded therein, the tooth cloth 5 made of nylon is adhered to the surface of the tooth rubber layer 3 and molded and vulcanized to form the plurality of circles. The belt body 4 is the reinforcement body 2 composed of braided cords 7, 7, ....
A toothed belt A embedded in was obtained. In the above adhesive treatment, the adhesive is uniformly impregnated from the surface of the round braid 7 to the inside.

[Structure of Toothed Belt A of Comparative Examples I and II] The same as in Example I except that the reinforcing member was composed of a single twisted yarn in Comparative Example I and a plied yarn in Comparative Example II. is there.

[Bending Fatigue Test Procedure] As shown in FIG. 4, four large pulleys 9, 9, ... And adjacent large pulleys 9,
A belt bending tester provided with four small pulleys 10, 10, ... Arranged between 9 is prepared, and a toothed belt is hung on the large and small pulleys 9 and 10 of the belt bending tester to be a weight 11. The toothed belt was run with a predetermined tension applied. The diameter of each small pulley 10 is 30.
mm. In addition, the toothed belt passes once through each of the four small pulleys 10, 10, ..., That is, when the number of times the belt is bent by each small pulley 10 is 4 times.
It was a cycle.

[0035]

[Table 1]

As is apparent from the test data of Table 1, the belt strength maintenance ratio of Example I is superior to Comparative Examples I and II at any number of belt bending times. . Especially, the number of belt flexions 1 × 10 ⁸
In Example I, the belt strength retention rate of 68.8% was exhibited, and the strength was only slightly reduced. However, Comparative Example I was 50.0% and Comparative Example II was 40.2%, which were both 50%.
It became less than%, and was significantly down.

The belt elongation at this time is the same as in Example I.
Is 0.21%, Comparative Example I is 0.32%, and Comparative Example II is 0.30%.
Had better dimensional stability.

As described above, in the present embodiment I, the hollow portion 8 in which the reinforcing body 2 embedded in the belt body 4 is cylindrically assembled by the odd number of yarns 6, 6, ... Since the braided braid 7 having the
As a structural characteristic of (1), uniform stress is applied to the monofilaments forming each yarn 6, and the bending fatigue resistance can be significantly improved.

Further, in this Example I, the tensile elastic modulus after stretching and dipping was larger than that of the reinforcing body composed of the twisted yarn due to the structure of the round braided braid 7, and the dimensional stability of the toothed belt A was improved. It is possible to improve the sex.

Further, in this Example I, the fraying to the cut surface at the time of processing the toothed belt A is improved because the fraying of the end portion due to the untwisting in the single-twisted yarn, the rung-twisted yarn, etc. is eliminated. It can be lost.

Further, in the present Example I, the directionality of twisting as in the case of the single twisted yarn is eliminated, so that the toothed belt A can be stably run, the unevenness during running can be eliminated, and uneven wear can be prevented. it can.

Further, in the present Example I, when the round braided cord 7 constituting the reinforcing body 2 is treated with an adhesive, the adhesive can be uniformly impregnated from the surface of the round braided cord 7 to the inside thereof, and the adhesive is applied. It is possible to prevent bending strain due to uneven distribution of impregnation of the agent.

Next, a bending fatigue test of the toothed belt A according to Examples II and III was carried out together with Comparative Example III under the following conditions and procedures, and the results are shown in Table 2 below. In addition,
The values in Table 2 also represent the belt strength maintenance rate.

[Structure of Toothed Belt A of this Embodiment II] As a round braid 7 constituting the reinforcing body 2, 5600 of Kevlar (trade name, manufactured by DuPont) (400de × 4) is used.
The procedure is the same as in Example I, except that a fully punched one (total denier number: 8000 de) was used.

[Structure of Toothed Belt A of this Embodiment III] As the round braid 7 constituting the reinforcing body 2, Kevlar (trade name, manufactured by DuPont) 800de (400de × 2) 9
The same as in the case of the present Example I, except that the fully-stretched one (total denier number: 7200 de) was used.

[Construction of Toothed Belt of Comparative Example III] As the round braid 7 constituting the reinforcing body 2, Kevlar (trade name)
This example is the same as Example 1 except that a 400-de (400-de x 1) 17-shot type (total denier: 6800 de) manufactured by DuPont was used.

[Procedure for Bending Fatigue Test] The procedure is the same as that in this Example I.

[0048]

[Table 2]

As is clear from the test data of Table 2, in both Example II and Example III, the belt strength retention rate was 50% at both belt bending times of 1 × 10 ⁷ and 1 × 10 ^8. Although it was higher, it was lower than 50% in Comparative Example III, and this Example II and this Example II
It can be seen that I has a higher belt strength retention rate than Comparative Example III. This means that this example II and this example II
In I, the hollow part 8 of the braided braid 7 is extremely small, and therefore the flattening phenomenon of the hollow part 8 during extension is unlikely to occur. In comparison, in Comparative Example III,
This is because a relatively large hollow part 8 is formed in the round braided cord 7 and the flattening phenomenon of the hollow part 8 is likely to occur during expansion.

Therefore, in Examples II and III, the flattening phenomenon when the hollow portion 8 of the round braided cord 7 is extended can be restricted, and the dimensional stability of the toothed belt A can be greatly improved. That is, these can extend the life of the toothed belt A.

(Second Embodiment) FIG. 5 shows a braided braid 7 used for a toothed belt A as an industrial belt according to the second embodiment. The toothed belt A has the structure of the first embodiment. The description is omitted because it is the same as the above (see FIG. 3). Also, the round braided cord 7 is configured by being assembled in a cylindrical shape with an odd number of three or more (five in this embodiment) yarns 6, 6, ... As in the first embodiment, and A feature of the embodiment is that it consists of left-handed and right-handed driven yarns 6 in which the twisting directions are set to S twist and Z twist in opposite directions. (Fig. 6
Shows the right transitional driving yarn 6). The type of yarn 6 is the same as that described in the first embodiment. Also, S
The number of twists of the twist and the Z twist is set within an error range of ± 20%. When the ply-twisted yarn and the rung-twisted yarn are used as the yarn 6, the twisting direction and the number of twists in this embodiment are both for the first twisting.

Next, a bending fatigue test of the toothed belt A according to this Example IV was carried out together with Comparative Example IV under the following conditions and procedures, and the results are shown in Table 3 below. In addition, this table 3
Also indicates the belt strength maintenance rate.

[Structure of Toothed Belt A of this Embodiment IV] As the round braid 7 constituting the reinforcing body 2, Kevlar (trade name: made by DuPont) 1500 de 5 striking (total denier: 7500 de) Was used. Also, the right transitional driven yarn 6 is twisted 20 times / 10 cm and S twist, and the left transitional driven yarn 6 is twisted 20 times / 10 cm, Z
Twisted. That is, the round braided braid 7 in which the twisting directions of the left transitional driven yarn 6 and the right transitional driven yarn 6 of the five driven yarns were set to the opposite directions of S twist and Z twist, was used as the reinforcing body 2. Others are the same as in the case of the present Example I.

[Construction of Toothed Belt of Comparative Example IV] The number of twists 2 for both the right-handed and left-handed driven yarns 6 of the round braid 7
The procedure is the same as in Example IV, except that the twist is 0 times / 10 cmZ.

[Procedure for Bending Fatigue Test] The procedure is the same as that in this Example I.

[0056]

[Table 3]

As is clear from the test data in Table 3, for example, when the number of flexing of the belt was 1 × 10 ⁸ , the belt strength maintenance ratio was 72.3% and the strength reduction was small in Example IV. In Example IV, the strength was significantly reduced to 62.7%, and there was a considerable gap between the two. This means that in the present Example IV, the left-handed and right-handed driving yarns 6 forming the round driving braid 7 are set in the opposite directions of S twist and Z twist, and the directionality of the driving yarns 6 is changed. This is due to the fact that they are offset and disappear.

Therefore, in Example IV, the bending fatigue resistance can be greatly improved by canceling the directionality of the driven yarn 6, and the life of the toothed belt A can be extended.

(Third Embodiment) FIG. 7 shows a round braided cord 7 used for a toothed belt A as an industrial belt according to the third embodiment, and the structure of the toothed belt A is the case of the first embodiment. The description is omitted because it is the same as the above (see FIG. 3). Also, the round braided cord 7 is configured by being assembled in a cylindrical shape with an odd number of three or more (five in this embodiment) yarns 6, 6, ... As in the first embodiment, and As a feature of the embodiment, a core thread 12 is inserted and arranged in the hollow portion 8 of the round braided cord 7. As the type of the core yarn 12, fibers of the same type or different types as the yarn 6 are used according to the use and purpose. Furthermore, the twisting coefficient of the core yarn 12 is K = 350 or less.

[0060]

[Equation 4]

K: twisting factor T: number of twists per 10 cm D: non-twisted yarn or untwisted yarn set to a total denier number. In this way, the twisting coefficient of the core yarn 12 is set to K = 350 or less, as is apparent from the data shown in FIG. 8 in which the twisting coefficient is in the range of K = 0-350. This is because the rate of utilization increases. The twisting direction of the core yarn 12 and the twisting method (multi-twisted yarn, single-twisted yarn, rung-twisted yarn, etc.) in the case of multi-step twisting are not limited. The type of yarn 6 is the same as that described in the first embodiment.

Next, a bending fatigue test of the toothed belt A according to the present Example V was carried out together with Comparative Example V under the following conditions and procedures, and the results are shown in Table 4 below. In addition, this table 4
In the numerical values of both Example V and Comparative Example V, the upper column shows the belt strength maintenance ratio and the lower column shows the belt elongation.

[Structure of Toothed Belt A of this Embodiment V] As the round braid 7 constituting the reinforcing body 2, Kevlar (trade name: manufactured by DuPont) 1500 de 5 striking (total denier: 7500 de) A hollow core 8 having a core thread 12 of 330 de made of Tetron inserted therein was used. Others are the same as in the case of the present Example I.

[Structure of Toothed Belt of Comparative Example V] The procedure of Example V is the same as that of Example V, except that the core yarn 12 is not inserted and arranged in the hollow portion 8 of the round braided cord 7.

[Procedure for Bending Fatigue Test] The procedure is the same as that in this Example I.

[0066]

[Table 4]

As is clear from the test data in Table 4, both the present Example V and the Comparative Example V were excellent in the belt strength maintenance rate. However, in belt elongation,
There is a considerable disparity between the two, especially the number of belt bends is 1
In the case of × 10 ⁸ , it was 0.10% in this example V, but was 0.21% in the comparative example V, and this example V was superior in dimensional stability. This means that the core yarn 12 is inserted and arranged in the hollow portion 8 of the round braided cord 7 in the present embodiment V, so that the core yarn 12 is roundly braided.
This is due to the fact that the flattening phenomenon at the time of expansion is regulated.

Therefore, in the present embodiment V, this core thread 1
By controlling the flatness phenomenon according to 2, it is possible to further improve the dimensional stability of the toothed belt A and also to increase the bending rigidity. In the present embodiment V, the bending rigidity of the toothed belt A (round punched braid 7) can be freely adjusted according to the purpose and application by selecting the material and thickness of the core thread 12. There is an advantage.

Next, a belt elongation test of the toothed belt A according to the present Example VI was conducted together with Comparative Example VI under the following conditions and procedures.

[Structure of Toothed Belt A of this Example VI] As the round braid 7 constituting the reinforcing body 2, three Kevlar (trade name: manufactured by DuPont) 1500 de drawn yarns (total denier: 4500 de) Made of nylon 330
De braided with a braid of 5 strands was used. Others are the same as in the case of the present Example I.

[Structure of Toothed Belt of Comparative Example VI] Reinforcement 2
As Kevlar (trade name, manufactured by DuPont) 1500d
e 3 ply plied yarn (total denier: 450
0 de) was used, and the same as in Example VI.

[Procedure for Testing Belt Elongation] As shown in FIG. 9, a biaxial running tester equipped with two pulleys 13 and 50 having a diameter of 50 mm is prepared, and the toothed belt A is tested by the biaxial running test. The toothed belt A was run on the pulleys 13 and 13 of the machine with a predetermined tension applied to the toothed belt A by the weight 14 to run the belt.

The test results are shown in FIG. As is clear from the test data, the belt elongation amount was as small as about 0.015 mm at a weight load of 300 kgf in this example VI, but was large at about 0.035 mm at a weight load of 300 kgf in this comparative example VI. The elongation amount was more than twice that of VI, and the dimensional stability of this Example VI was superior. This means that the core yarn 12 inserted and arranged in the hollow portion 8 of the braided braid 7 is three draw-aligned yarns in the present Example VI, whereas in the comparative example VI, three-plied plied yarns are used. It is based on the difference of being.

Therefore, in the present Example VI, the strength utilization factor and elastic modulus utilization factor of the reinforcing member 2 can be improved by the twisting characteristic of the core yarn 12, and further, by the structural characteristic of the round braid 7, the outside of the twisting yarn can be obtained. It is possible to improve the dimensional stability of the toothed belt A by covering the deformation due to the stress.

In each of the above-mentioned embodiments, the toothed belt A is shown as an industrial belt, but the invention is not limited to this and, for example, V is used.
It goes without saying that it may be a transmission belt such as a belt, a flat belt and a ribbed belt, or a conveyor belt.

[0076]

As described above, according to the present invention as set forth in claim 1, the reinforcing body is constituted by the round braided braid which is cylindrically assembled with an odd number of yarns of three or more. In addition to improving flex fatigue resistance, it can also increase tensile elastic modulus,
It is possible to improve dimensional stability and workability, and prevent occurrence of flare on the cut surface of the industrial belt and uneven wear.

According to the second aspect of the present invention, since the round braided braid is braided with an odd number of yarns of 3 or more and 9 or less, flex fatigue resistance and dimensional stability of the industrial belt are improved. It can be sufficiently improved and its life can be extended.

According to the third aspect of the present invention, the round braided braid is an odd number of three or more made up of left-handed and right-handed braided yarns in which the twisting directions are set to S twist and Z twist in opposite directions. Since the number of yarns is set, the bending fatigue resistance and the dimensional stability of the industrial belt can be sufficiently improved, and the life of the industrial belt can be extended.

According to the present invention of claim 4, since the adhesive is uniformly impregnated from the surface to the inside of the round braid, the bending strain caused by the uneven distribution of the impregnation of the adhesive is prevented. be able to.

According to the fifth aspect of the present invention, since the core yarn is provided in the hollow portion of the round braid, the dimensional stability can be further improved in addition to the bending fatigue resistance.

According to the present invention of claim 6, the twisting coefficient of the core yarn provided in the hollow portion of the round braid is K = 350.
Less than

[0082]

[Equation 5]

K: Twisting coefficient T: Number of twists per 10 cm D: Since the total denier number is set, the dimensional stability of the industrial belt is improved in addition to the improvement of the strength utilization factor and elastic modulus utilization factor of the reinforcing body. You can also plan.

[Brief description of drawings]

FIG. 1 is an enlarged vertical side view of a round braided cord according to a first embodiment.

FIG. 2 is an enlarged front view of the round braided cord in the first embodiment.

FIG. 3 is a vertical cross-sectional front view of the toothed belt according to the first embodiment.

FIG. 4 is a schematic configuration diagram of a belt bending tester.

FIG. 5 is an enlarged front view of a round braid in the second embodiment.

FIG. 6 is an enlarged view of a right transitional driving yarn in a second embodiment.

FIG. 7 is an enlarged vertical side view of a round braided cord according to a third embodiment.

FIG. 8 is a data diagram showing the relationship between the twisting coefficient of the core yarn and the tenacity factor and elastic modulus factor in the third example.

FIG. 9 is a schematic configuration diagram of a biaxial running test machine.

FIG. 10 is a data diagram showing the relationship between the weight load and the amount of belt elongation of the toothed belt according to the third embodiment.

[Explanation of symbols] 2 ... Reinforcement 4 ... Belt body 6 ... Thread 7 ... Round braid 8 ... Hollow part 12 ... Heart thread A ... Toothed belt (industrial belt)

Claims (6)

[Claims] 1. An industrial belt in which a reinforcing body made of fibers is embedded in a belt main body, wherein the reinforcing body has a hollow portion formed in a cylindrical shape by an odd number of three or more yarns. An industrial belt characterized by being made with a round braid. 2. The industrial belt according to claim 1, wherein the braided round braid is formed into a cylindrical shape with an odd number of threads of 3 or more and 9 or less. 3. The braided round braid is cylindrical with an odd number of three or more yarns consisting of left-handed and right-handed driven yarns whose twisting directions are set to S twist and Z twist in opposite directions. The industrial belt according to claim 1, wherein the industrial belt is assembled into 4. The industrial belt according to claim 1, wherein the round braided cord is uniformly impregnated with an adhesive from the surface to the inside. 5. The industrial belt according to claim 1, wherein a core yarn is provided in the hollow portion of the round braided cord. 6. The twisting coefficient of the core yarn is K = 350 or less. The industrial belt according to claim 5, wherein K: twist coefficient T: number of twists per 10 cm, D: total denier number.