JPH0389049A - Sail cloth for toothed belt - Google Patents

Abstract

PURPOSE:To provide the sail cloth of a toothed belt with self-stretchability so as to enhance its strength by using non-stretch yarn as warp in the sail cloth of the toothed belt and constraining the non-stretch yarn with plural stretch yarns. CONSTITUTION:In stretch filament 15, two stretch yarns 16a, 16b are mutually twisted. Non-stretch yarn 17 is disposed in the zigzag state so as to pass though up and down successively between the plies of the stretch yarns 16a, 16n. Small loops 18 are formed at a small pitch on both sides of the stretch yarns 16a, 16b. The non-stretch yarn 17 is used as warp in the sail cloth 5 of a toothed belt 1. The strength of the sail cloth is thus enhanced, and abrasion resistance and durability are heightened.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the structure of canvas for toothed belts.

2. Description of the Related Art In general, a toothed belt 1 has a mesh i3 formed on one side of a main body portion 2 made of rubber, as shown in FIG.
A tensile member 4 is embedded in the main body portion 2 in its length direction. A canvas 5 is attached to the meshing surface of the meshing teeth 2 along the tooth-shaped surface of the main body portion 2.

When manufacturing this T& belt 1, as shown in FIG. 5 are fitted together, a tensile member 4 is wound around the outer circumference, and a rubber fabric 8 is placed on the outer circumference. When this rubber fabric 8 is heated and pressurized, the third
As shown in the figure, the rubber fabric 8 is pushed into the female die 6 through the spacing between the tensile members 4, and is vulcanized to form the meshing teeth 3.

At this time, the canvas 5 is pushed into the female mold 6 together with the rubber fabric 8 to form an engaging surface along the surface of the engaging teeth 3. Initially, the length matches the circumference of the toothed belt 1. However, when molding the meshing teeth 3, it is necessary to extend the teeth to a length that follows the tooth profile of the belt 1. Therefore, the canvas 5 is required to be able to easily extend in the longitudinal direction of the toothed belt 1.

Conventionally, threads extending in the length direction of the toothed belt 1 in canvas 5 for toothed belts of this kind (hereinafter referred to as warp threads 9, and threads intersecting with these threads as weft threads 10. However, these "warp threads" and The term "weft"(gA'! IJ structural structure and upper weft) does not necessarily correspond to the crimped yarn of synthetic fibers such as nylon.

That is, the canvas 5 is woven with a suitable structure using crimped yarn as the warp yarn 9 and ordinary synthetic fiber yarn as the weft yarn 10. Therefore, this canvas 5 is contracted in the direction of the warp yarn 9 due to the crimp force of the crimped yarn, and the circumferential length of the mold 7 coincides with the circumferential length. Then, by applying a tensile force to this, it can be easily expanded and can follow the meshing surface of the meshing teeth 3 of the toothed belt 1.

Problems to be Solved by the Invention However, in this type of line 1 (in the case of the drying belt IG, the canvas 5 forms the meshing direction of the meshing teeth 3 and directly contacts the pulley. The canvas 5 is directly subjected to wear and friction caused by the pulley, and the toothed belt 1
plays an important role in determining the durability of

However, the crimped yarn used as the warp yarn 9 of the canvas 5 does not necessarily have high strength, and is also inferior in terms of 1liJ abrasion resistance. Therefore, as the plow belt 1 is used for a long period of time, the canvas 5 may wear out due to repeated contact with the pulleys, or the meshing teeth 3 may repeatedly deform, causing repeated local forces to be applied to the canvas 5. The canvas 5 was often cut and the meshing teeth 3 were often cracked, making it impossible to provide sufficient durability.

If a normal filament yarn that is not crimped is used as the warp yarn 9, it will have greater strength and excellent abrasion resistance than a crimped yarn. Furthermore, if a yarn with greater strength and excellent heat resistance, such as a filament type aramid fiber, can be used, it is possible to obtain a toothed belt 1 with extremely excellent durability.

However, ordinary filament threads have low elasticity,
In the canvas 5 using this as the warp yarn 9, the canvas 5 stretches during the molding of the toothed belt 1 and cannot follow the female die 6 of the mold 7, making it impossible to mold the toothed belt 1. In particular, when aramid fibers are used, aramid fibers are fibers that are inherently non-stretchable, and it is difficult to impart stretchability through crimping or the like. It is not necessarily impossible to forcefully impart stretchability, but the strength will drop to 11, and the characteristics of an aramid fiber will be lost.

Also, Publication of Utility Model Publication No. 15628/1983 and Japanese Unexamined Patent Application Publication No. 63-27
Publication No. 0944 discloses the use of a composite thread 13 in which aramid fibers 12 are spirally wound around polyurethane elastic threads 11 as the warp threads of the canvas 5 of the toothed belt 1. In this composite yarn 13, when the polyurethane elastic yarn 11 is contracted, the spiral aramid l fibers 12 are loosened, and the composite yarn 13 can be expanded and contracted by a length corresponding to the slack. be.

However, in this yarn, a sufficiently long aramid fiber 12 is wound around the polyurethane elastic thread 11, so that no mutual restraining force acts between the polyurethane elastic thread 11 and the aramid fiber 12. As a result, mutual slippage occurs between the two, and the slack of the aramid fibers 12 appears as irregular loops 14 as shown in FIG. The loop 14 protrudes from the surface of the canvas 5 and becomes thick.

Due to the nature of the toothed belt 1, it is preferable that the tension member 4 is provided as close as possible to the bottom of the meshing teeth 3, and the canvas 5
It is necessary to avoid thickening. Furthermore, if a large number of loops 14 protrude irregularly, they are likely to be locally abraded, reducing the durability of the toothed belt l.

The present invention has been made in view of the above circumstances, and uses an elastic yarn that is elastic in itself, has high strength in a fully stretched state, and has excellent abrasion resistance and durability. The object of the present invention is to provide a canvas fabric 5 for a toothed belt used as a warp yarn.

As a means for solving the problems, the present invention forms meshing teeth at a constant pitch on one side of a main body part, embeds a tensile member extending in the length direction of the main body part, and the meshing teeth In the canvas in the toothed belt formed by pasting the canvas along the surface of the canvas, the threads extending in the length direction of the toothed belt in the canvas,
It is an elastic yarn formed by arranging a zigzag-shaped non-stretchable yarn so as to pass through two or more elastic yarns twisted together in order to reciprocate and pass through the twists. and any thread that intersects this.
It is a symbol of the temple.

FIG. 4 does not show the elastic yarn 15 used in the present invention. In this elastic thread 15, 16a and 16b are elastic threads, and two elastic threads 16a, 16
b are twisted together.

As the stretchable yarns 16a and 16b, winding yarns of synthetic fibers, polyurethane elastic yarns, rubber yarns such as hydrogenated nitrile rubber, etc. can be used. Moreover, three or more of these elastic threads 16 can also be used.

17 is a non-stretchable thread, which is the stretchable thread 16a.

The elastic threads 16a are arranged in a zigzag pattern so as to pass through the twisted threads of the threads 16b sequentially.

Small loops 118 are formed at small pitches on both sides of 16b.

The material of this non-stretchable thread 17 is not particularly limited, and ordinary synthetic fibers such as nylon and polyester can be used. In addition, aramid fiber, aromatic polyester fiber, high-strength vinylon fiber, carbon fiber,
It is also possible to use highly rigid yarns such as glass fibers and metal m-fibers, and it is possible to obtain the toothed belt 1 with extremely excellent durability.

In particular, when a high-rigidity yarn is used as the non-stretchable yarn 17, it is preferable to use a yarn having a small single fiber fineness as the high-rigidity yarn. In addition, it is preferable that the fineness of the raw yarn is as small as 100 d or less, and furthermore, when using multiple yarns,
It is preferable to use it in a stretched state without twisting it. By doing so, the rigidity of the high-rigidity yarn as a yarn is reduced, and the non-stretchable yarn 17 is easily bent to form the loop 18. The elastic yarn 15 has a certain amount of elasticity, and the canvas 5 has high elasticity, and even when attached to the meshing surface of the toothed belt 1, the canvas 5 is thin and has teeth with excellent performance. It becomes the attached belt 1.

Note that the stretchable thread 15 having this structure can be manufactured extremely easily. FIG. 5 shows a state in which the elastic yarn 15 is manufactured. That is, the two stretchable threads 16a and 16b are wound twice in different directions around the linearly arranged non-stretchable thread 17 in a fully stretched state. Although two stretchable threads 16 are used in the drawings, three or more stretchable threads 16 may be wound alternately in different directions.

In this state, since the plurality of elastic yarns 16a16b are wound around the non-elastic yarn 17 in different directions, the elastic yarn 16a16b is wound around the non-stretchable yarn 17 in different directions.
a and 16b intersect at least every half turn,
When the elastic yarns 16a, 16b are contracted by removing the tensile force in this state, the elastic yarns 16a, 1
6b contracts while restraining the non-stretchable thread 17, and bends the non-stretchable thread 17 between the restrained parts to form a loop 18.
is formed.

As a result, the non-stretchable yarn 17 is curved in a zigzag shape, and the zigzag-shaped non-stretchable yarn 17 is bent into elastic yarns 16a, 1.
6b to fix the condition, the elastic yarn 15 in the form shown in FIG. 4 is obtained.

Next, in order to weave the canvas 5, the warp threads 9 are the warp threads 9, and the weft threads 10 are arbitrary threads. In this weaving, either the warp threads 9 or the weft threads 10 may be used as the warp threads during weaving, and either may be used as the weft threads. In addition, by weaving the warp yarns 9 as weft yarns during weaving in a vertical hollow weave, it is possible to form a cylinder shape without joining both ends, and to fit it into the mold 7 and use it for molding.

When weaving the canvas 5, the stretchable threads 15 are woven under tension, so the stretchable threads 15 are woven in a stretched state. In addition, when the canvas 5 is woven, the warp yarns 9 and the weft yarns 10 are intertwined and restrain each other, so that the canvas 5 is sufficiently woven only by the elasticity of the elastic yarns 16a and 16b in the elastic yarn 15. cannot be contracted.

Therefore, the canvas 5 is subjected to a relaxing process to contract the elastic threads 15, thereby causing the canvas 5 to contract. In the relaxing process, the woven canvas 5 is immersed in water (preferably warm water) and vibrated without applying any tension to it. Thereby, the canvas 5 can be sufficiently shrunk in the vertical direction.

Function In the canvas 5 of the present invention, the elastic yarns 15, which are the warp yarns 9, have non-elastic yarns 17 that move forward in a zigzag shape and are restrained by elastic yarns 16a, 16b.
From 16b, the curvature 1 peak protrudes as a loop 18,
The loops 18 are formed regularly.

When a tensile load is applied to this stretchable thread 15, the stretchable threads 16a and 16b are stretched, and the non-stretchable thread 17 is stretched in a straight line until it reaches the state shown in FIG. be able to.

In the fully stretched state, the non-stretchable thread 17
By bearing the load and being in a sufficiently elongated state where it is no longer able to elongate, the characteristics corresponding to the type of non-stretchable yarn can be fully expressed.

Therefore, when molding the toothed bells 1 to 1 using this canvas 5, as the rubber fabric 8 enters the mold 6 of the mold 7, the canvas 5 expands and It can take a bent state along the mold 6.

In addition, when the canvas 5 is attached to the meshing surface of the toothed belt 1, the III-contractile yarn 15 is sufficiently long, the non-stretchable yarn 17 extends linearly, and the II-contractile yarn 16a extends in a straight line.
, 16b are wound, as shown in FIG.

Therefore, the strength of the canvas 5 in this state is borne by the strong non-stretchable yarns 17. In addition, the non-stretchable yarn 17 will mainly bear the burden of wear caused by the pulleys and thermal deterioration due to frictional heat when the toothed belt 1 is driven.

Effects of the Invention According to the present invention, as the warp yarns 9 in the canvas 5 of the toothed belt 1 are used, non-stretchable yarns 17 having excellent strength, abrasion resistance, heat resistance, etc., the strength of the canvas 5 is increased. The warp threads 9 are large in size, and even when driven in contact with a pulley, the warp threads 9 will not be worn out or deteriorated by frictional heat. Therefore, the canvas 5 is not cut or the meshing teeth 3 are not cracked, and the toothed belt 1 with extremely excellent durability can be obtained.

In particular, by using high-rigidity fibers such as aramid fibers as the non-stretchable yarn 17, it is possible to achieve higher durability and heat resistance for high-load transmission.

Further, according to the present invention, the non-stretchable threads 17 are arranged in a zigzag pattern, and the non-stretchable threads J7 include a plurality of stretchable threads 16a,
16b, the elastic yarn 15 has great elasticity even though the non-elastic yarn 17 itself does not have elasticity, and the canvas 5 has a large elasticity in the longitudinal direction of the toothed belt 1. It has great extensibility and can be easily molded into a toothed belt 1.

Furthermore, in the elastic yarn 15, loops 18 caused by the bending of the non-elastic yarn 17 are formed at regular small intervals, and since the loops 18 are restrained and fixed by the elastic yarn 16a16b, the canvas 5 is Since large loops are not irregularly formed on the surface and the canvas 5 does not become unnecessarily thick, the tensile body 4 of the toothed belt 1 is formed very close to the tooth bottom. It becomes a toothed belt 1 with good performance.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the toothed belt of the present invention. FIGS. 2 and 3 are longitudinal sectional views showing the state in which the toothed belt is manufactured. FIG. 4 is a front view of the stretchable yarn used as the warp of the canvas of the present invention, and FIG. 5 is a front view showing the state in which the stretchable yarn is manufactured. 6th
The figure is a front view of a conventional elastic yarn.

Claims (1)

[Claims] 1 Meshing teeth (3) with a constant pitch on one side of the main body part (2)
a tensile member (4) extending in the length direction thereof is embedded in the main body portion (2), and a canvas (5) is attached along the surface of the meshing tooth (3). Toothed belt (1)
In the canvas (5) in the canvas (5), a thread (9) extending in the length direction of the toothed belt (1) in the canvas (5)
However, two or more elastic threads (16a, 1
6b), the elastic yarn (15) is formed by arranging a zigzag-shaped non-stretchable yarn (17) so as to sequentially reciprocate and penetrate through the twists of the elastic yarn (15). ) and an arbitrary thread (10) intersecting the threads (10).