JPH0419444A - Industrial belt - Google Patents

Abstract

PURPOSE:To improve durability of a belt by constituting the belt into a double structure formed of a core part consisting of combined filament no-twist fiber bundle and a shell part consisting of twist-added fiber bundle coating the core part at a twist angle. CONSTITUTION:A reinforced body 4, buried in a belt main unit 1 of an industrial belt to consist of fiber, is constituted into a double structure formed of a core part 5 and a shell part 6. The core part 5 consists of no-twist fiber bundle by combining by a filament unit the first fiber 5a of high strength further with high elastic modulus of amide fiber, polyarylate system fiber, etc., and the second fiber 5b composed of synthetic fiber excellent in wear resistance of nylon, tetron, polyester, etc. The shell part 6 consists of twist-added fiber bundle of high strength high elastic modulus fiber of alamide fiber, polyarylate system fiber, etc., coating the periphery of the concerned core part at a twist angle relating to the core part 2. Thus, fatigue by contact friction between the fellow filaments is reduced, and durability of the belt can be improved by increasing fatigue resistance as a total unit of the reinforced body at the running time of the belt.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an industrial belt, and particularly to an improvement in a reinforcing body (tensile body) embedded in the belt body along its length.

(Prior art) Conventionally, power transmission belts such as toothed belts, healds, flat belts, ribbed healds, and industrial belts such as transportation belts have been manufactured with high strength, high elastic modulus, and high dimensional stability. In order to satisfy these characteristics, a reinforcing core made of fibers or a reinforcing body such as a cloth-like material is embedded in the belt body.

The six reinforcing bodies used are fiber bundles made of high modulus and high tensile strength fibers such as polyester fibers, aromatic polyamide fibers, glass fibers, carbon fibers, etc., and a large number of these fiber bundles are aligned. code is commonly used.

Incidentally, it is preferable to use a non-twisted fiber bundle that has not been heated at all as the fiber bundle has high modulus and tensile strength and can exhibit the physical properties of the fiber well. However, on the other hand, it is difficult to handle the fiber bundle. In addition, due to bending and running of the belt, especially the surface layer portion of the fiber bundle is more prone to bending fatigue and filament breakage than the inside.

For this reason, it is usually used with twists such as rung twist, single twist, and plied twist. Therefore, due to the heated fiber bundle, when the belt runs, the modulus is low and the strength per cross-sectional area of the fiber bundle is also low.
A problem arises in that durability is low.

Therefore, in order to solve the contradictory problems caused by both non-twisted fiber bundles and heated fiber bundles, conventionally,
The one disclosed in Japanese Patent No.-8453 has been proposed.

As shown in FIG. 7, this belt core uses a cord in which easily bonded fiber bundles such as polyamide synthetic fibers are spirally wound around a non-twisted fiber bundle a.

(Problem to be solved by the invention) However, in this proposal, the fiber amount is extremely small at a ratio of 1/10 to 1/15 to the fiber bundle a inside the fiber bundle wound around the cord, and Since the fiber bundle a is spirally wound, the fiber bundle a in the center is partially exposed to the outside. For this reason, the cord diameter of the core differs between the portion around which the fiber bundle is wound and the portion without the fiber bundle, and the cord diameter is not uniform in the length direction. As a result, when the belt is used, for example, as a synchronized belt that is bent at multiple angles, there will be areas where stress is concentrated on the center body corresponding to the bent parts of the belt, which may lead to early breakage of the belt and reduce durability. In terms of sex, it is not enough.

Therefore, in the specification and drawings of Japanese Patent Application No. 1-69570, the applicant proposed a core portion consisting of a non-twisted fiber bundle of high-strength, high-modulus fibers such as aramid fibers and polyarylate fibers; We proposed a cord with a double structure, including a shell part that covers the outer periphery of the core part and is made of heated fiber bundles with a larger twist angle than the core part.

According to this proposal, high modulus and high tensile strength of the cord can be obtained, and stress concentration can be avoided when the cord is bent, and the durability of the belt can be improved.

However, as a result of intensive research by the present inventors, it has been found that the above proposal leaves room for further improvement. That is, since the core of the cord is not twisted, the filaments are packed more densely than in conventional heating cords. Therefore, the contact area between the filaments increases, and fatigue due to contact friction between the filaments increases while the belt runs.

The present invention has been made in view of the above points, and its purpose is to further improve the structure of the fiber bundles constituting the belt core, thereby reducing friction and wear of the core when the belt is bent. The aim is to suppress the fatigue caused by this and further increase the durability of the belt.

(Means for Solving the Problems) In order to achieve the above object, the invention according to claim (1) is characterized in that the core part of the endless reinforcing body is made of high-strength, high-elasticity fiber such as aramid fiber or polyarylate fiber. A blend of synthetic fibers and synthetic fibers with excellent abrasion resistance such as nylon, Tetron, and polyester in filament units (con+mingl).
e) Consisting of untwisted fiber bundles.

That is, the present invention provides a reinforcing body made of fibers embedded in the belt body of an industrial belt, a first fiber with high strength and high modulus such as aramid fiber or polyarylate fiber, and nylon, tetron, A core part is made of a non-twisted fiber bundle made by mixing filament units of second fibers made of synthetic fibers with excellent abrasion resistance such as polyester, and the outer periphery of the core part is covered with a twist angle to the core part. It is characterized by having a double structure with a shell portion made of a heated fiber bundle of high-strength, high-modulus fibers such as aramid fibers and polyarylate fibers. Here, the mixed non-twisted fiber bundle of the core section refers to raw yarn that is not heated after spinning, and is usually one that has been naturally twisted a very small amount (about 1 to 10 times per meter). say.

In the invention according to claim 2, in the core portion having the above structure, the total denier number of the second fibers is made to be a ratio of 20 to 40% of the denier number of the entire core portion.

In the invention according to claim (3), the filament diameter of the second fiber in the core portion is set to be equal to or smaller than the filament diameter of the first fiber.

(Function) With the above configuration, in the invention according to claim (1), the core portion of the reinforcing body includes the first fibers having high strength and high modulus of elasticity and the second fibers made of synthetic fibers having excellent abrasion resistance. Since it is composed of untwisted fiber bundles mixed in filament units, fatigue caused by contact friction between the filaments can be reduced. As a result, the fatigue resistance of the reinforcing body as a whole when the belt runs can be improved, and the durability of the belt can be increased.

In the invention according to claim 2J, since the core portion of the reinforcing body contains 20% or more of the second fiber with excellent wear resistance, fatigue caused by wear can be effectively reduced, and the belt after running can be It is possible to increase the strength retention rate.On the other hand, since the proportion of the same fiber is less than 40%, the first fiber with high strength and high modulus is contained at 60% or more, and is concentrated in the first fiber. The stress is not so large, and it is possible to sufficiently achieve high modulus and high tensile strength of the reinforcing body.

In addition, in the invention according to claim (3), since the filament diameter of the second fiber is smaller than that of the first fiber, the filament of the second fiber or the first fiber will fit between the filaments of the first fiber and fatigue caused by wear. can be effectively reduced.

(Example) Embodiments of the present invention will be described below based on the drawings.

FIG. 3 shows a toothed belt B as an industrial belt according to an embodiment of the present invention. In the figure, reference numeral 1 denotes a rubber structure serving as a belt body, and the bottom thereof has a large number of teeth 2, 2. ... are formed in line in the length direction, and these tooth portions 2, 2 .・・・
By meshing with the outer peripheral teeth of a toothed pulley (not shown), the rotation is synchronized with the pulley and power is transmitted. The rubber structure 1 is made of chloroprene rubber (neoprene), styrene butadiene rubber, shrimp chlorohydrin rubber, polyurethane rubber, hydrogenated acrylonitrile butadiene rubber, etc., and is a known rubber suitable for the intended use of belt B. Formed by a compound.

Tooth portions 2, 2 of the rubber structure 1. ... surface (tooth surface)
is covered with a tooth canvas 3. This toothed canvas 3 uses threads or blended yarns made of 6 nylon, 66 nylon, 46 nylon, aromatic polyester, Tetron, cotton, rayon, Teflon, etc., singly or in combination, and has the durability required as a belt toothed canvas. Woven to meet abrasion resistance and friction coefficient.

Further, inside the rubber structure 1, there are an endless plurality of eight bodies 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4 . ... (reinforcing bodies) are embedded in parallel in the belt width direction at a constant pitch and in a spiral shape at an angle with respect to the belt length direction.

As shown in enlarged detail in FIG. 2, each of the eight bodies 4 includes a core portion 5 made of a non-twisted fiber bundle, and covers the outer periphery of the core portion 5.
It has a double structure with a shell part 6 made of heating fiber bundles twisted at an angle to the core part 5.

As shown in enlarged detail in FIG. 1, the core portion 5 includes a first fiber 5a having high strength and high elastic modulus, such as aramid fiber (aromatic polyamide fiber) or polyarylate fiber;
5a, . . . and second fibers 5b, 5b made of synthetic fibers with excellent abrasion resistance such as nylon, Tetron, polyester, etc.
, ... are mixed in filament units to form a non-twisted fiber bundle. On the other hand, the shell portion 6 is made of a heated fiber bundle of high-strength, high-modulus fibers such as aramid fibers and polyarylate fibers.

Moreover, the second fibers 5b, 5b in the core portion 5.

... is the entire core portion 5 (for example, 3000 denier)
The filament diameter of the second fibers 5b, 5b, ... is 20% to 40%.
For example, the filament diameter of the first fibers 5a, 5a, . . . is 9 μm or less (for example, 12 μm).

Further, the cross-sectional area ratio of the core portion 5 to the cord diameter of each of the eight bodies 4 is in the range of 60 to 90%, and the shell portion 6
The twist angle θ perpendicular to the fiber axis of the fiber bundle is 25
~50''.

Therefore, in the above embodiment, each of the six bodies 4 of the belt B is composed of a core part 5 made of a non-twisted fiber bundle and a shell part 6 made of a heated fiber bundle surrounding the core part 5, and the core part 5 has a high height. Physical properties such as modulus and high tensile strength can be obtained. Also, when bending 6 bodies 4 (Bell) B),
Since the apparent distortion (elongation, compression) of the six bodies 4 is reduced, there is no stress concentration, and the fatigue resistance of the six bodies 4 can be maintained as a whole while the belt is running, thus improving the durability of the belt B. It is possible to increase

Further, since the outer peripheral shell portion 6 of the six bodies 4 is a heated fiber bundle, unlike the case of a non-twisted fiber bundle, high-order processing can be easily performed in the same way as with only a heated fiber bundle. Moreover, when the six bodies 4 are composed of only non-twisted fiber bundles, the diameter of the six bodies 4 becomes thinner,
Although the meshing of the toothed boob with the toothed portion becomes poor, in this embodiment, the cord diameter of the six bodies 4 can be adjusted to the set value by the shell portion 6 on the outer periphery of the core portion 5, so that the toothed portion 2 of the belt B .2. Good engagement with the pulley can be ensured.

Furthermore, since the cross-sectional area ratio of the core portion 5 to the cord diameter of each of the six bodies 4 is 60% or more, the fiber can exhibit high modulus and high tensile strength due to the core portion 5. Moreover, since the upper limit of the above ratio is 90%, the core part 5 can be uniformly covered by the fiber bundle of the shell part 6, and from a microscopic point of view, the cord diameter of the six bodies 4 can be made uniform in the belt length direction. Stress concentration at the time of belt bending can be prevented, and therefore the strength of the cord can be kept high after the six bodies 4 are fatigued by belt running.

In addition, since the twist angle θ in the direction perpendicular to the fiber axis of the fiber bundle in the shell portion 6 of each of the six bodies 4 is 25 to 50 degrees, the strength of the coat after fatigue of the six bodies 4 is maintained as high as described above. be able to.

In addition, since the shell portion 6 is composed of a heating fiber bundle,
Good adhesion between the body 4 and the rubber structure 1 can be maintained.

The core portions 5 of each of the six bodies 4 are made of first fibers 5a, 5a, . . . having high strength and high modulus of elasticity, and second fibers 5b, 5b, . Since it is composed of untwisted fiber bundles mixed in filament units, fatigue caused by contact friction between the filaments can be reduced, and the fatigue resistance of the reinforcing body as a whole when the belt runs is improved. The durability of belt B can be further improved.

In addition, since the core part 5 of each of the six bodies 4 contains 20% or more of the second fibers 5b, 5b, etc., which have excellent wear resistance, fatigue caused by wear can be effectively reduced, and after running, Belt B
It is possible to increase the strong retention rate of On the other hand, since the ratio of the same fibers 5b, 5b, . . . is less than 40%, the first fibers 5a, 5a, .
is contained in 60% or more, and the first fibers 5a, 5
The stress concentrated on a,... is not so large, and each 6
It is possible to achieve high modulus and high tensile strength of the body 4.

Furthermore, since the filament diameter of the second fibers 5b, 5b, . . . is less than or equal to that of the first fibers 5a, 5a, . .

5a, . . . will fit in between the filaments, and fatigue caused by wear can be effectively reduced.

Note that the above embodiment is a case where the present invention is applied to toothed belt B, but the present invention is applied to other industrial belts, such as V
Of course, the present invention can also be applied to power transmission healds, transportation belts, etc., such as belts, flat belts, and ribbed belts.

Here, the results of a test in which six toothed belts B having the configuration of the above embodiment were manufactured and the strength of six of the toothed belts B were evaluated will be specifically described. The manufactured toothed belt B has a width of 19 mm, a tooth pitch of 8.0 mm, and a pinch between 6 bodies of 1.5++++s.
, the circumference was 40 inches.

The rubber structure was a rubber compound using chloroprene rubber, and the tooth canvas was a woolly canvas made of 66 nylon. The core portions of the six bodies were made of a mixture of aramid fibers with a filament diameter of 12 μm as the first fibers and nylon fibers with a filament diameter of 9 μm as the second fibers. Further, aramid fibers of 3000 denier (2000 filaments) were used for the shell portion, and the twist angle θ of the fiber bundle in the direction perpendicular to the fiber axis was set to θ-45°.

As shown in FIG. 6, the test machine for bending and running the toothed belt B manufactured in this way has four toothed pulleys 10 to 13 (all have 24 teeth) each having a rotation center in the horizontal direction. and four tension pulleys 14-17. The four toothed pulleys 10 to 13 are arranged in pairs to face each other vertically and horizontally, and the belt B to be tested is hung on these toothed pulleys 10 to 13. Further, the tension pulleys 14 to 17 are arranged between the toothed pulleys 10 to 13, and apply a predetermined tension to the belt B by pressing the back surface of the bell I-B in a reverse bend state. The lowermost toothed pulley 10 is used as a drive pulley and is rotated at a predetermined rotational speed to cause the belt B to travel while being bent.

After this running test, six belts were taken out from each belt B and their strength retention coefficients A were measured. In the core part, the total denier number (D, +DN), which is the sum of the denier number of the aramid fiber and the denier number DN of the nylon fiber, is maintained at D-10N-3000 denier; The ratio of denier number of nylon fiber is DN/
When the strong retention rate A was determined when (D-+D N ) was varied from 0 to 60%, the test results shown in FIG. 4 were obtained. In addition, the above ratio DN / (D, +DN
) exceeds 60%, the belt elongates so much during running that the teeth no longer mesh, and the belt loses its function as a toothed belt.

According to Figure 4, when the denier of the nylon fiber reaches 20% of the 3000 denier of the core, the effect of reducing wear appears, and the strength retention rate A after belt running is 85%.
rise above. However, this increase occurs only when the ratio of nylon fibers exceeds 40%, and as the stress concentrated on the aramid fibers increases, the strength retention rate A decreases on the contrary.

Therefore, it was confirmed that the durability of belt B is improved when the core portion contains 20 to 40% of nylon fibers with high abrasion resistance.

Next, a similar test was conducted with the filament diameter of the nylon fibers set to 26 μm, which is larger than that of the aramid fibers. The results are shown in FIG. Comparing this figure 5 with figure 4, we get
The effect of blending aramid fiber and nylon fiber is not very visible. This is thought to be because the filament diameter of the nylon fibers was larger than that of the aramid fibers, so the filaments of the nylon fibers could no longer effectively fit between the aramid fibers. Therefore, it can be seen that the filament diameter of the nylon fiber is desirably equal to or smaller than that of the aramid fiber, and that the effects of the present invention can be obtained.

(Effects of the Invention) As described above, according to the invention according to claim (1), the reinforcing body in the industrial belt includes a core portion made of a non-twisted fiber bundle,
The outer periphery of the core part is coated and has a double structure with a shell part made of heated fiber bundles twisted at an angle to the core part, and the core part is made of high-strength, high-modulus fibers and synthetic fibers with excellent abrasion resistance. By using commingle yarn with
Fatigue due to wear between filaments when the belt runs can be significantly reduced, and the durability of the belt can be effectively increased.

Further, according to the invention according to claim (2), since the core portion of the reinforcing body contains 20% or more of synthetic fibers with excellent wear resistance, fatigue caused by wear can be effectively reduced, and the belt after running can be effectively reduced. In addition to increasing the strength retention rate of the fibers, the ratio of the same fibers is less than 4090, so the stress concentrated on the high strength and high modulus fibers can be kept low while increasing the modulus and tensile strength of the reinforcement. can be achieved.

Further, according to the invention according to claim (3), since the filament diameter of the synthetic fiber with good abrasion resistance is less than the filament diameter of the high-strength, high-modulus fiber, the filament of the synthetic fiber and the filament of the high-strength, high-modulus fiber This can further effectively reduce fatigue caused by wear between filaments.

[Brief explanation of the drawing]

Figures 1 to 6 show embodiments of the present invention, with Figure 1 being an enlarged cross-sectional view of the core of the belt, Figure 2 being an enlarged perspective view of the belt core, and Figure 3 showing the longitudinal direction of the belt. Figure 4 is a characteristic diagram showing the strength retention rate of the belt as a result of changes in the blending ratio of nylon fibers when the filament diameter of the nylon fibers in the core part is smaller than that of the aramid fibers. This figure is a diagram corresponding to FIG. 4 showing the same characteristics when the filament diameter of the nylon fiber is larger than that of the aramid fiber, and FIG. 6 is a schematic diagram of a testing machine for carrying out a belt bending running test. FIG. 7 is a perspective view of a conventional belt core. A... Toothed belt...Rubber structure (belt body) 4... Core body (reinforcement body) 5... Core portion 5a... First fiber 5b... Second fiber 6. ... Shell part θ... Twisting angle of shell part DN / (DC+ + DN) Fig. 4 DN/ (Da DN Fig.

Claims (3)

[Claims] (1) An industrial belt in which a reinforcing body made of fibers is embedded in the belt main body, wherein the reinforcing body is made of first fibers having high strength and high modulus of elasticity and synthetic fibers having excellent abrasion resistance. It has a double structure consisting of a core part made of a non-twisted fiber bundle in which the fibers of 2 are mixed in filament units, and a shell part made of a heated fiber bundle that covers the outer periphery of the core part with a twist angle to the core part. An industrial belt characterized by: (2) The second fiber in the core part has a denier number of 20
The industrial belt according to claim 1, characterized in that the fibers are mixed with the first fibers at a ratio of ~40%. (3) The filament diameter of the second fiber in the core part is
The industrial belt according to claim 1 or 2, characterized in that the filament diameter is equal to or less than the filament diameter of the first fiber.