JPS627414B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a toothed belt, and particularly to a toothed belt in which the shearing force and abrasion resistance of the toothed portion of the belt are significantly improved by coating the surface of the toothed portion with a special canvas. In recent years, toothed belts have been recognized for their superior functionality and are being used in a wide variety of fields.
Since the belt is used under harsh conditions such as high temperatures, the tooth material deteriorates and shear cracks are likely to occur in the teeth, causing the teeth to fly off and often causing belt breakage accidents. As a solution to this problem, a canvas woven with woolly-processed crimped nylon threads as warp threads and non-stretchable threads as weft threads has been used to cover the tooth surface. ,
As shown in Figure 1, there is a relationship between the denier number of the yarn and the crimp rate, and the crimp effect does not appear unless thin filament yarn is used. It was used as a 40d multifilament. However, in order to improve the shearing force and abrasion resistance of the toothed part, it is necessary to twist a large number of 40D threads together and use them as canvas for covering the toothed part. PLD (pitch line difference, the gap between the center line of the tension member and the tooth valley) is internationally regulated to ensure good engagement between the teeth and the pulley teeth, so the number of strands is increased. Therefore, in order to improve the shearing force and abrasion resistance of the belt teeth, it is necessary to increase the twist density. (If the cover factor, which is the coefficient of For canvas fabrics, the thickness of the warp and weft yarns are approximately the same due to its workability, and usually warp denier/weft denier =
It was woven at a rate of 0.95. Therefore, the shearing force and abrasion resistance of the belt teeth are still a step forward, and improving them has been a major challenge. In view of the above-mentioned circumstances, the present invention was devised to solve the problems by improving the structure of the canvas.The main feature of the present invention is that it does not use the conventional crimped elastic canvas. , weaving with warp yarns that are thicker and have a higher number of twists (twist coefficient) than conventional crimped yarns, and weft yarns made of twisted yarns or monofilament yarns that are thinner than the warp yarns, and the density of the weft yarns is reduced, on the tooth surface. The shearing force and abrasion resistance of the belt teeth are significantly improved by using the canvas as a covering. Hereinafter, specific embodiments of the toothed belt according to the present invention will be explained in more detail with reference to the accompanying drawings. FIG. 2 is a partially cross-sectional perspective view of the toothed belt according to the present invention, where a is the belt body, 1 is a low elongation and high strength fiber tensile rope made of polyester, nylon, rayon, glass fiber, etc. (natural rubber), a single material or a blend of synthetic rubber, and a belt made of a urethane elastomer, and are buried in parallel at the pitch line position in the stretch rubber layer 2, and tooth shapes 3 are made of the same material as the stretch rubber layer 2. The elastic rubber layer 2 is integrated with the stretch rubber layer 2 at a portion thereof. Then, on the surface of the toothed portion 3,
A rubber-covered elastic canvas 4, which is a feature of the present invention and has high strength and excellent abrasion resistance, is coated and pasted. As shown in FIG. 3, this canvas 4 is made of filament yarns such as nylon, polyester, vinylon, human silk, aromatic polyamide, cotton, spun yarns, or blended yarns made by blending or twisting two or more yarns of the above materials.
Using mixed twisted thread as tissue thread, thickness 210d or more,
It is constructed of a warp 4a made of twisted yarn with a twist coefficient of 1.5 or more and a weft 4b made of twisted yarn of the various materials mentioned above or monofilament yarn such as nylon or polyester, and is 0.8 times or less of the warp (warp thickness / weft thickness = 1.2 or more) ) is woven into a plain weave, twill weave, satin weave, etc. at a thread density of a cover factor of 10 or less, and the warp threads 4a are arranged on the surface of the toothed portion 3 in the longitudinal direction of the belt to cover it. Here, the cover factor means thread density, and is usually expressed as the number of threads that can be lined up in one inch. In the above, the warp 4a of the canvas 4
When the thickness of the weft yarn 4b is less than 210d, the strength of the yarn decreases, and when the twist coefficient is less than 1.5, the elongation of the yarn is insufficient.On the other hand, when the cover factor of the weft yarn 4b is 10
Above this, the density of the weft yarns becomes too high and weaving becomes impossible.
Furthermore, if warp thickness/weft thickness = 1.2 or less, warp 4
Since there is a problem that the strength of the yarn a decreases, the warp 4a constituting the canvas 4 has a thickness of 210d or more, a twist coefficient of 1.5 or more, a cover factor of 10 or less for the weft 4b woven with this warp 4a, and a warp thickness of 210d or more. /Weft thickness=
A value of 1.2 or higher is effective. In this way, the canvas 4 covering the surface of the tooth portion 3 is constructed by weaving thick warp yarns 4a with a high twist coefficient on a layer of low density weft yarns 4b made of thin twisted yarns, and the warp yarns 4a having a large number of twists. Since the warp threads 4a can be woven with high tension during weaving, the weaving shrinkage of the warp threads 4a can be increased. Also, the strength can be increased. Note that the above explanation mainly concerns the weft 4b of the canvas 4.
In addition to the twisted yarn, the weft yarn 4b can also be made of monofilament yarn such as nylon or polyester as mentioned above, and if such a monofilament yarn is used, the rigidity of the weft can be improved. It is possible to increase the weave shrinkage of the warp threads 4a. Generally, 40d multifilament is used as the warp of crimpable canvas that has been conventionally used, but since the single yarn is made of 3 to 4d thin yarn with a low degree of polymerization, it is less strong. However, the canvas used for the belt teeth of the present invention has poor abrasion resistance and cannot provide the strong shearing force required for the toothed canvas. The drawbacks of traditional canvas have been improved, and thick thread,
For example, warp yarns of 100d, 210d, 420d, 840d, and 1260d can be used, increasing the strength of the warp yarns.Furthermore, since crimped yarns are not used, the bulk of the twisted yarns can be reduced, making it possible to use thicker twisted yarns than before. It is extremely advantageous that the PLD can be made to match the PLD, and as a result, the tooth shear force and wear resistance of the toothed belt can be significantly improved. Further, although the canvas 4 is usually made of a plain weave canvas, it is also possible to use a twill weave canvas or a satin weave canvas for the purpose of improving belt life.
Among them, in the case of plain weave canvas, the warp 4a and the weft 4b
and are alternately cross-stacked vertically, so warp 4
The wavy intersections of the weft yarns 4a and 4b are formed continuously in the warp and weft directions, but when twill weave or satin weave canvas is used, the wavy intersections of the warp yarns and the weft yarns 4b are formed every several warp yarns and weft yarns. There are fewer wave-like intersections than ordinary plain-woven canvas, and the rubber penetrates not only between the threads but also between the intersections. When this is used in the belt tooth profile, the warp and weft threads are directly connected to each other when the belt is bent. It has the advantage of avoiding contact and significantly improving belt life. Next, the toothed belt according to the present invention will be explained using examples. Example 1 Structure shown in Table 1 below A canvas according to the present invention was manufactured, and the physical properties of the warp yarns were measured in comparison with a conventional crimped canvas, and the results shown in Table 2 were obtained.

【table】

[Table] As is clear from Tables 1 and 2 above, the warp, which is thicker than the weft and has a higher twist coefficient, and the thinner weft,
The canvas according to the present invention, which is woven with a reduced weft density, exhibits higher strength than conventional crimped canvas.
It is confirmed that it has extremely excellent performance. Example 2 A conventional canvas (crimped fabric) with the above structure and a canvas according to the present invention were used as cover fabrics, wrapped around a toothed cylindrical mold, and a tensile rope was spun thereon. PLD is manufactured using a well-known press-in molding method in which an unvulcanized rubber sheet of a certain thickness is wrapped around the top, and the rubber is press-fitted into the tooth grooves of the drum by external pressure and heating.
A toothed belt with = 0.686mm, width 19mm, and number of belt teeth 87T was manufactured. When the tooth shear force of each of the toothed belts thus obtained was measured, the results shown in Table 3 and FIG. 4 were obtained. In the figure, ● indicates the conventional canvas, and ○ and △ indicate the case of the present invention.

[Table] Next, wrap the above toothed belt around an 18T (18 teeth) driving pulley and a 32T driven pulley with a tension of 15 kg.
Place a 52mmφ idler pulley on the back of the belt,
The wear condition of the tooth canvas was measured with a microscope after running for 1000HRS at 7200rpm and 5th load.
The results shown in the table and FIG. 5 were obtained. In the figure,
A is a conventional canvas belt, B and C are canvas belts according to the present invention.

[Table] As is clear from Table 3 (Figure 4) and Table 4 (Figure 5) above, the toothed belt according to the present invention has a higher shear force than the toothed belt using conventional crimped canvas. It can be seen that both the canvas wear rate and the canvas wear rate are excellent. As described above, the toothed belt according to the present invention has warp yarns that are thicker than conventional crimped yarns and have a higher twist coefficient, and weft yarns that are thinner than the warp yarns and are made of twisted yarn or monofilament yarn, and have a reduced density on the tooth surface. It has a structure in which it is covered with a rubberized canvas woven from crimped canvas, which makes the PLD more uniform and significantly improves the shearing force and abrasion resistance of the belt teeth compared to a toothed belt that is covered with a conventional crimped canvas. This toothed belt solves the problems of conventional toothed belts and is particularly suitable as a synchronous transmission belt used under severe conditions such as high speed rotation, high load, and high temperature.

[Brief explanation of the drawing]

Fig. 1 is a chart showing the relationship between the thickness of the canvas warp used in a toothed belt and the crimp rate, Fig. 2 is a partial cross-sectional perspective view of the toothed belt according to the present invention, and Fig. 3 is a toothed belt according to the present invention. Fig. 4 is a diagram showing the relationship between the canvas strength of various toothed belts and the shearing force of the belt teeth, and Fig. 5 shows the warp thickness and canvas of various canvases used for toothed belts. FIG. 2 is a chart showing the relationship between the a... Belt body, 1... Tensile body, 3... Tooth section, 4... Canvas (elastic canvas with rubber), 4a...
Warp, 4b...weft.

Claims (1)

[Scope of Claims] 1. A rubber toothed belt in which a tooth profile with a constant pitch is formed on the inside and a tensile material is embedded at the pitch line position, and the tooth profile surface has warp thread thickness/weft thread thickness = 1.2 or more. And the canvas is covered with a warp made of twisted yarn with a thickness of 210 d or more and a twist coefficient of 1.5 or more, and a weft made of twisted yarn or monofilament yarn with a weft cover factor of 10 or less. Features a toothed belt. 2. The toothed belt according to claim 1, wherein the twisted yarns of the warp and weft are twisted yarns selected from the group consisting of filament yarns and spun yarns of nylon, polyester, vinylon, human silk, aromatic polyamide, cotton, etc. . 3. The toothed yarn according to claim 1, wherein the twisted yarns of the warp and weft are twisted yarns selected from the group consisting of blended yarns or mixed yarns made of nylon, polyester, vinylon, human silk, aromatic polyamide, cotton, etc. belt. 4. The toothed belt according to claim 1, 2, or 3, wherein the monofilament yarn of the weft is a monofilament yarn selected from the group consisting of nylon and polyester. 5. Claim 1, wherein the canvas is a canvas having a texture selected from plain weave, twill weave, or satin weave,
The toothed belt according to item 2, 3, or 4.