JPH03213747A - Belt for industrial purpose - Google Patents

Abstract

PURPOSE:To increase a tensile elastic modulus in addition to the improvement of an anti-bending fatigue quality and improve sizing stability and workability, by constituting a reinforcement body with braided cords each of which is plaited cylindrically with an even number of more than four thread lines. CONSTITUTION:A toothed belt A is equipped with a belt main body 4 consisting of an extension portion rubber layer 1 and a fibre-made reinforcement body 2 embedded within the extension portion rubber layer 1, and tooth portions 3 integrally formed on one side of the rubber layer 1 out of the same quality rubber with that of the rubber layer 1, and a tooth cloth 5 is coveringly and integrally attached on the tooth portion 3 surface side of the belt main body 4. The reinforcement body 2 is constituted with a plurality of braided cords 7, 7,... each of which is plaited cylindrically with an even number of more than four thread lines 6, 6,... and has a hollow portion 8. As for the number of the thread line 6 constituting a braided cord 7, it is decided that the number is an even number of more than four. The reason for this number is that the cylindrical hollow portion 8 is required to be formed at the inside of the cord.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to industrial belts, and particularly to improvements in reinforcing bodies (tensile strength bodies) embedded in belt bodies.

(Prior Art) Conventionally, industrial belts such as transmission belts and transportation belts, such as toothed belts, ■ belts, flat belts, and ribbed belts, have high strength, high elastic modulus, high dimensional stability, and Since characteristics such as high adhesiveness are required, reinforcing cords made of fibers and reinforcing bodies such as cloth-like materials are embedded in the belt body in order to satisfy these characteristics. As this reinforcing body, - For boat fishing, a twisted yarn made by twisting a plurality of threads is used, and the types thereof can be divided into plied yarn, single twisted yarn, rung twisted yarn, etc. depending on the twisting method. Currently, among the twisted yarns, plied yarns are most often used for reinforcing the industrial belts.

However, in industrial belts in which the reinforcing body is made of plied yarn, there are parts where the monofilaments strongly contact each other at deep angles within the plied yarn, so wear, breakage, or strength loss can occur early from these strong contact parts. There was a problem that the bending fatigue resistance deteriorated.

Therefore, as an industrial belt that has improved the above-mentioned problem (bending fatigue resistance), a belt in which the reinforcing body is made of, for example, single-twisted yarn or rung-twisted yarn has been proposed (Japanese Patent Application Laid-open No. 1983-1993-1).
(See Publication No. 19744).

(Problem to be Solved by the Invention) However, as mentioned above, industrial belts in which the reinforcing bodies are made of single-twisted yarns or rung-twisted yarns are subjected to stretching and dip processing compared to belts in which the reinforcing bodies are made of plied yarns due to their structure. The subsequent tensile modulus becomes small, resulting in a decrease in dimensional stability.

In addition, since the single-twisted yarn and rung-twisted yarn mentioned above are twisted only in one direction, they tend to untwist and become frayed at the ends, making them difficult to process. There is also the problem that fray is more likely to occur.

Furthermore, in industrial belts that use single-twisted yarn or rung-twisted yarn as a reinforcing body, since the single-twisted yarn has a directionality as described above, it tends to be biased in one direction during running, causing uneven wear on one side. There are also problems. Therefore, for example, as disclosed in Japanese Patent Application Laid-Open No. 56-103008,
A conveyor belt has been proposed in which uneven wear is eliminated by using, as a reinforcing body, S-twist and Z-twist single-twist yarns arranged alternately. However, when this reinforcing structure is adopted for a power transmission belt in which two cords (single-twisted yarn) are arranged in parallel and spirally, a total of four cord cut surfaces are created on the left and right belt end surfaces, making use of the cord strength. This results in a decrease in the rate, making it difficult to employ.

In addition, when treating the cords that make up the reinforcing body with adhesive,
When the cord is made of twisted yarn, it is not possible to uniformly impregnate the adhesive from the surface of the cord to the inside of the cord, resulting in areas where the adhesive is thinner and areas where the adhesive is more concentrated. However, the concentration tends to be particularly high in areas near the cord surface.

Cords (twisted yarn) with uneven adhesive impregnation distribution suffer from large distortions on the surface when bent, resulting in poor bending fatigue resistance and are not used as reinforcing bodies for industrial belts. hard.

The present invention has been made in view of these points, and its purpose is to improve bending fatigue resistance by constructing the reinforcing body with a traditional circular braid instead of twisted yarn. The object of the present invention is to obtain an industrial belt with increased tensile modulus and improved dimensional stability. Another object is to improve workability by eliminating fraying at the ends due to untwisting, and to make the cut surface less prone to fray when processing the belt. Furthermore,
The objective is to run an industrial belt stably and prevent uneven wear. Another object of the present invention is to uniformize the impregnation distribution of the adhesive to the cords and the like constituting the reinforcing body, thereby preventing bending distortion.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention as set forth in claim (1) is directed to an industrial belt in which a reinforcing body made of fibers is embedded in the belt body, In this case, the reinforcing body is constituted by a round braided cord having a hollow part, which is made up of an even number of threads of four or more in a cylindrical shape.

Furthermore, the solution of the present invention as set forth in claim (2) is such that the adhesive is uniformly impregnated from the surface to the inside of the round braid constituting the reinforcing body.

(Function) With the above configuration, in the present invention as set forth in claim (1), the reinforcing body made of fibers embedded in the belt main body is a hollow cylindrical structure made of an even number of threads of 4 or more. Since it is composed of a round braided cord having a section, the structural characteristic of the round braided cord is that uniform stress is applied to the monofilaments constituting the yarn, and the bending fatigue resistance is greatly improved. Further, due to the structure of the circular braid, the tensile modulus after drawing and dip treatment is higher than that of a reinforcing body made of twisted yarn, thereby improving the dimensional stability of the industrial belt. Furthermore, fraying at the ends of single-twisted yarns, rung-twisted yarns, etc. due to untwisting is eliminated, improving workability, and moreover, fraying is less likely to occur on the cut surface during belt processing.

In addition, the directionality of the twist as in the case of single-twisted yarn is eliminated, so that the industrial belt runs stably, and there is no deviation during running, thereby preventing uneven wear.

Furthermore, in the present invention according to claim (2), when the round braid constituting the reinforcing body is treated with an adhesive, the adhesive is uniformly impregnated from the surface to the inside of the round braid,
Bending distortion caused by uneven distribution of adhesive impregnation is prevented.

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

FIG. 3 shows a toothed belt A as an industrial belt according to an embodiment of the present invention. The toothed belt A has an extension rubber layer 1
, a reinforcing body 2 made of fibers embedded in the extension rubber layer 1, and a rubber made of the same material as the extension rubber layer 1 integrally formed on one side of the extension rubber layer 1 (lower side in FIG. 3). Teeth 3
The belt body 4 is comprised of a belt body 4 consisting of
A canvas 5 is integrally attached to the surface side of the tooth portion 3.

As a feature of the present invention, as shown in enlarged detail in FIG. 1 and FIG. A plurality of round braids 7 having a hollow part 8 braided into a cylindrical shape,
7. ...It's extremely well-structured. The yarns 6 may be made of inorganic fibers, organic fibers, metal fibers, etc., and may also be spun yarns made of long fibers and short fibers, or mixed yarns thereof. It may be selected as appropriate depending on the required performance of the attached belt A. Further, the number of threads 6 forming the round braid 7 is an even number of 4 or more. This is because it is necessary to form a cylindrical hollow part 8 inside the braid, and if the number of braids is an odd number, the hollow part 8 cannot be formed. However, it is desirable to limit the number of implants to 16 or less. This means that if the number of threads exceeds 16,
6. This is because the hollow portion 8 is too large compared to the size of the round braid 7, which causes the round braid 7 to become flattened when buried in the extension rubber layer 1. Furthermore, the total denier number of the yarn 6, the monofilament denier number, etc. may be appropriately selected according to the required performance of the toothed belt A.

Further, the round braid 7 assembled as described above is made of, for example, epoxy resin, before being embedded in the extension rubber layer 1.
Adhesive treatment and stretching treatment are performed using a combination of adhesives such as isocyanate compounds, ethylene urea compounds, and resorcinol formalin latex (RFL). Note that the adhesive treatment method is to apply the adhesive to the reinforcing body 2.
The dipping method is preferable because it is necessary to uniformly impregnate the round braid 7 from the surface to the inside.

Next, a bending fatigue test was conducted on the toothed belt A according to the present example configured as described above, together with a comparative example, under the following conditions and procedures, and the results are shown in Table 1 below. Note that the values in Table 1 represent the belt strength maintenance rate.

[Configuration of the toothed belt A of this embodiment] As the round braid 7 constituting the reinforcing body 2, a 4-strand round braid (total denier: 6000 de) of Kevlar (product name: DuPont) 1500 de is used. there was.

This round braid 7 is first dipped in an adhesive made of incyanate compound to form a sub-coat layer, then dipped in an adhesive made of resorcinol formalin or latex (RFL) to form a second coat layer, and then , a top coat layer was formed by immersing it in CR adhesive rubber, and then a stretching process was performed. This stretched multiple round braid 7
,7. ... are arranged in a spiral on the extension rubber layer 1 made of CR rubber, and the teeth 3 made of CR rubber are formed so as to embed the round braids 7 thereon. By applying a nylon canvas 5 to the surface and molding and vulcanizing it, the plurality of circular braids 7.7. ... A toothed belt A was obtained in which the reinforcing body 2 constructed with the above was embedded in the belt main body 4. In addition, during the adhesive treatment, the adhesive is uniformly impregnated from the surface to the inside of the round braid 7.

[Construction of Toothed Bell of Comparative Example A] The reinforcing body was constructed of single-twisted yarn in Comparative Example I and double-twisted yarn in Comparative Example (■), but was the same as that of the present example.

[Procedure for bending fatigue test] As shown in Fig. 4, four large pulleys 9, 9°... and four small pulleys 10. 10. A belt bending tester equipped with... was prepared, and the toothed belt was passed through the large and small pulleys 9 and 1o of the belt bending tester, and a predetermined tension was applied to the toothed belt with the weight 11. I ran it in this condition. Note that the diameter of each of the small pulleys 10 is 30 mm. In addition, the toothed belt goes around and the four small pulleys 10, 10. ...
One cycle is defined as passing through each of the belts once, that is, the number of times the belt is bent by each small pulley 10 four times.

Table 1 As is clear from the test data in Table 1, it can be seen that the belt strength maintenance rate of this example is better than that of Comparative Example I and Comparative Example (2) at any number of times the belt is bent. In particular, when the number of times the belt was bent was 1 x 108, the present example showed a belt strength maintenance rate of 76.4%, and the strength decreased only slightly, but Comparative Example I had a belt strength retention rate of 50.0%.
In Comparative Example ■, it was 40.2%, which was less than 50% in both cases, which was a significant decrease.

In addition, the belt elongation at this time is 0°21% in this example.
, 0.32% in Comparative Example I and 0.30% in Comparative Example 2, and the dimensional stability of this example using round braid 7 was better.

As described above, in this embodiment, the reinforcing body 2 embedded in the belt main body 4 is made of an even number of threads 6.6. ...
Since the round braid 7 has a hollow part 8 that is braided into a cylindrical shape, the structural characteristics of the round braid 7 are that uniform stress is applied to the monofilaments that make up each yarn 6, which increases the durability. Bending fatigue resistance can be significantly improved.

Further, in the above embodiment, the tensile 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 7, which improves the dimensional stability of the toothed belt A. I can do it.

Furthermore, in the above embodiment, the fraying of the ends caused by untwisting of single-twisted yarn, rung-twisted yarn, etc. is eliminated, improving workability, and moreover, it is possible to eliminate play on the cut surface during processing of toothed belt A. can.

Further, in the above-mentioned embodiment, there is no directionality of twist as in the case of single-twisted yarn, so that the toothed belt A can run stably, eliminate deviation during running, and prevent uneven wear.

Furthermore, in the above embodiment, when the round braid 7 constituting the reinforcing body 2 is treated with an adhesive, the adhesive can be uniformly impregnated from the surface to the inside of the round braid 7, and the impregnation distribution of the adhesive is Bending distortion caused by non-uniformity can be prevented.

In addition, although the toothed belt A is shown as an industrial belt in the above embodiment, it is not limited to this, and may be a transmission belt or a transportation belt such as a V belt, a flat belt, or a ribbed belt. Needless to say.

(Effects of the Invention) As explained above, according to the present invention as set forth in claim (1), the reinforcing body is made of a round braid braided in a cylindrical shape with an even number of threads of 4 or more. This structure not only improves bending fatigue resistance but also increases tensile modulus, improves dimensional stability and workability, and reduces the occurrence of fray and unevenness on cut surfaces of industrial belts. Abrasion etc. can be prevented.

Furthermore, according to the present invention as set forth in claim (2), since the adhesive is uniformly impregnated from the surface to the inside of the round braid constituting the reinforcing body, the bending distortion can be prevented.

[Brief explanation of drawings]

The drawings show embodiments of the present invention; FIG. 1 is an enlarged vertical side view of a circular braid, FIG. 2 is an enlarged front view of the same, FIG. 3 is a longitudinal front view of a toothed belt, and FIG. 4 is a sectional view of a bent belt. It is a schematic block diagram of a test machine. 2... Reinforcement body 4... Belt body 6... Thread 7... Round braid 8... Hollow part A... Toothed belt (industrial belt)

Claims (2)

[Claims] (1) An industrial belt in which a reinforcing body made of fibers is embedded in the belt main body, the reinforcing body being rounded and having a hollow part formed into a cylindrical shape by an even number of threads of 4 or more. An industrial belt characterized by being made of braided cord. (2) The industrial belt according to claim (1), wherein the round braid constituting the reinforcing body is uniformly impregnated with an adhesive from the surface to the inside.