JPH0882346A - V-ribbed belt - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent the reduction of transmission power when driving the rear surface, to prevent vertical tearing at each part between ribs, and to prevent the belt from rolling over. [Structure] The back cloth 5 attached to the back surface of the adhesive rubber portion 2 of the V-ribbed belt A is made of a woven fabric. As the warp yarn 6 of the back cloth 5, there is no lower twist and upper twist is 3 to 10 times / 10
The one set to cm is adopted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission V-ribbed belt, and more particularly to an improvement of a back cloth.

[0002]

2. Description of the Related Art A V-ribbed belt, which is a type of power transmission belt, has a smaller thickness than a V-belt and therefore has less bending stress, has a wide usable range for small pulleys, can be designed compactly, and has an energy-saving effect. It is remarkable. In addition, the V-ribbed belt, when driven compared to the V-belt,
It has many advantages such as a decrease in belt tension due to sinking into the pulley groove, and thus a longer belt life. It is also used for general industry, automobiles, agricultural machinery, home appliances, etc. It is in the process of expansion.

Generally, in this type of V-ribbed belt, a plurality of V-shaped rib portions are provided along the longitudinal direction of the belt on one surface (belt inner surface) of the adhesive rubber portion in which a plurality of core wires are embedded. A back cloth made of rubber-attached canvas is attached to the other surface (back surface of the belt) of the adhesive rubber portion.

As a means for improving the mechanical characteristics of this V-ribbed belt, the structure on the back side of the belt is characterized in that a back rubber portion is provided on the back side of the adhesive rubber portion, and short fibers are attached to the back rubber portion. Some are mixed so as to be oriented in the width direction (see Japanese Utility Model Laid-Open No. 4-119651).

[0005]

However, when the V-ribbed belt having the above-mentioned structure is used for a serpentine drive in which power may be transmitted on the back surface of the belt, it is a woven product of warp and weft. In the V-ribbed belt that uses a back cloth made of canvas on the back of the belt,
There is a problem that unevenness appears on the back surface of the belt due to the texture of the canvas, the contact area with the pulley is reduced, slipping easily occurs, and the power transmission capability on the back surface of the belt is significantly reduced.

On the other hand, in the V-ribbed belt using a rubber layer on the back surface of the belt without using a back cloth, the power transmission capability on the back surface of the belt is improved, but the ribs are vertically split at the valley portion (in the longitudinal direction of the belt). There is a problem that cracks easily occur. In addition, V with short fibers mixed in the back rubber part
In the ribbed belt, if there is even one poor dispersion, it becomes the starting point of cracking and does not necessarily lead to an increase in life.

By the way, a V-ribbed belt has been proposed in which two layers of biased sudar records with rubber are arranged on the back surface of the adhesive rubber portion to enhance the rigidity in the belt width direction and the belt longitudinal direction ( JP-A-3-
(See Japanese Patent No. 33536 and Japanese Utility Model Laid-Open No. 55-45082).

The present invention focuses on this Suda record. That is, the object of the present invention is to use a sudak record as a back cloth, and by devising the orientation of the warp threads and the weft threads, and further the warp threads constituting the back cloth, to prevent the reduction of the transmission capacity at the time of driving the back surface and the rib portion. The purpose is to prevent vertical tearing that occurs at various parts between the belts and to prevent the belt from rolling over.

[0009]

To achieve the above object, the present invention provides a plurality of V-shaped rib portions in the belt longitudinal direction on one surface of an adhesive rubber portion in which a plurality of core wires are embedded. For the V-ribbed belt provided along with the back cloth adhered to the other surface of the adhesive rubber portion, the following means for solving the problems were taken.

That is, the first means of solving the problems of the present invention is to provide a plurality of warp yarns having no lower twist and upper twist of 3 to 10 times / 10 cm, and each warp yarn having a predetermined interval in the longitudinal direction. It is characterized in that the back cloth is constructed by weaving with a plurality of wefts connected at different positions.

A second solving means of the present invention is the same as the first solving means, wherein the back cloth has a warp density of 40 to 55 yarns / 5 cm.
In addition, the back cloth has a weft density of 3 threads / 5 cm or less.

A third solving means of the present invention is the first or second means.
In the solution means, the back cloth is attached to the other surface of the adhesive rubber portion so that the warp threads extend along the belt width direction.

A fourth solving means of the present invention is the third solving means, wherein the warp of the back cloth is 0 to 1 in the belt width direction.
It is characterized by being oriented so as to have an inclination of 0 °.

[0014]

With the above construction, in the first means for solving the problems of the present invention, the back cloth is the woven fabric, and the warp has no lower twist and the upper twist is set to 3 to 10 times / 10 cm. Therefore, the rubber is easily impregnated into the fiber, and the crack resistance is improved. In addition, the unevenness due to the texture such as the conventional canvas does not appear on the back surface of the belt, the contact area between the pulley and the V-ribbed belt is widened, slip is prevented, and the transmission capability at the time of driving the back surface is improved.

In the second solution of the present invention, the back cloth has a warp density of 40 to 55 yarns / 5 cm and a weft yarn density of 3 yarns /
Since it is set to 5 cm or less, the bending fatigue resistance of the V-ribbed belt is improved. Therefore, it is possible to use the pulley with a small diameter.

In the third solution of the present invention, the warp along the belt width direction of the back cloth further improves the bending fatigue resistance of the V-ribbed belt.

According to the fourth solution of the present invention, the inclination of the warp of the back cloth with respect to the belt width direction is 0 to 10 °, which is balanced with the spiral angle of the core wire, and the V-ribbed belt does not roll over.

[0018]

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

FIG. 1 shows a V-ribbed belt A according to an embodiment of the present invention. The V-ribbed belt A is a single NR, SBR, CR, HNBR, etc. in which a plurality of core wires 1 made of ropes with low elongation and high strength such as polyester fiber, nylon fiber, aromatic polyamide fiber, etc. are embedded. Material or an adhesive rubber portion 2 formed by blending these materials, and three V-shaped rib portions 3 are provided on one surface of the adhesive rubber portion 2 (the inner surface which is the lower surface in FIG. 1) in the belt longitudinal direction. It is formed integrally along. The rib portions 3 are made of the same material as the adhesive rubber portion 2, and the short fibers 4 are mixed so as to be oriented in the belt width direction. Further, on the other surface of the adhesive rubber portion 2 (the back surface which is the upper surface in FIG. 1), a back cloth 5 having a surface treated so as to be easily adhered to the adhesive rubber portion 2 is integrally attached.

Characteristic of the present invention, the back cloth 5 is constructed by woven with a plurality of warp threads 6 and weft threads 7, and at least one layer is laminated on the back surface of the adhesive rubber portion 2. Each of the warp yarns 6 does not have a large number of twists as used in tires, and has no lower twist, that is, only upper twist, and the upper twist is set to 3 to 10 times / 10 cm, The back cloth 5 is formed by weaving the warp threads 6 arranged in parallel with each other and connecting them with a plurality of weft threads 7 at predetermined intervals in the longitudinal direction.

The warp 6 has a woven structure of, for example, 840 de / 2, and the material is 6 nylon, 6,
Polyamides such as 6-nylon, 4,6-nylon and 1,2-nylon, polyester, polyvinyl alcohol, aramid, etc. are included. On the other hand, examples of the material of the weft yarn 7 include cotton.

The above-mentioned warp yarn 6 is twisted 3 to 10 times / 10 cm.
When the number of times is less than 3 times / 10 cm, the warp 6 is loosened and the strength is lowered, while when the number of times is more than 10 times / 10 cm, the rubber is poorly impregnated when vulcanized and becomes a crack initiation point on the back surface of the belt. Because it is not suitable. It should be noted that this sloppy fabric is preferably subjected to a general RFL treatment as an adhesive treatment.

The density of the warp yarn 6 is 40 to 55 yarns / 5 cm.
In addition, the density of the weft yarns 7 is set to 3 threads / 5 cm or less. In this way, the density of the warp yarns 6 is 40 to 55 yarns / 5.
The reason why it is set to cm is that if it is less than this, troubles are likely to occur during belt molding, while if it is more than 55 pieces / 5 cm, rubber impregnation is poor and crack initiation points tend to occur.

Further, the warp yarns 6 are oriented along the belt width direction and at an angle of 0 to 10 ° with respect to the belt width direction. The angle varies depending on the length of the V-ribbed belt A and the winding pitch of the core wire 1, but it is desirable that the spiral angle θ of the core wire 1 and the angle α formed with the belt width direction of the warp yarns 6 are substantially equal (FIG. 2).
reference).

Hereinafter, the effects of the present invention will be confirmed by more specific experimental examples.

The warp yarn 6 is made of 6,6 nylon, the weft yarn 7 is made of cotton 8
40de / 2 was woven with a woven fabric and warped 6
The density was 52 lines / 5 cm. RFL the back cloth 5
Dip treated with liquid. A V-ribbed belt (outer peripheral length 920 mm) A was produced using this back cloth 5. The adhesive rubber part 2 and the rib part 3 were made of a chloroprene rubber composition, and the core wire 1 was made of a polyester fiber rope.

Next, in order to clarify the effect of the present invention, the V-ribbed belt A of the present invention using the woven fabric as the back cloth 5 (Example of the present invention) and the V-ribbed belt A using the conventional canvas (Comparative Example 1) ) And a V-ribbed belt A (Comparative Example 2) in which short fibers are not mixed in the back surface will be described below.

First, the vertical tear was pulled at two ribs as a boundary with a tensile tester at 50 mm / min, and the vertical tear between the ribs was examined. The results are shown in Table 1. As is apparent from the data in Table 1, it was confirmed that the inventive example with the slackening specification had almost the same vertical tear resistance as Comparative Example 1 with the conventional canvas specification, but the Comparative Example 2 without the back fibers had the vertical tearing resistance. The resistance was very low.

Next, a rear surface transmission capacity test was conducted on a V-ribbed belt A having the same specifications as those of the vertical tearing and a belt length of 1100 (3PK1100) having three ribs. The test conditions at this time are as follows.

That is, as shown in FIG.
The V-ribbed belt A is wound around a driving pulley 11 having a diameter of 15 mm, an idler pulley 12 having a diameter of 45 mm, and a tension pulley 13 having a diameter of 45 mm. 15 kg
The rotation speed of the drive pulley 11 is 4900 rpm, the idler pulley 12 and the tension pulley 13 are unloaded with f / 3 ribs, and the load of the driven pulley 14 is varied, and the test is performed at room temperature.
The driven pulley 14 when the slip ratio of the V-ribbed belt A is 2%
The load was measured.

As a result, as shown in Table 1 below, it was confirmed that the present invention example of the slackening specification has almost the same back transmission force as that of Comparative Example 2 without the back short fibers, but it is the same as that of the conventional canvas specification. In Comparative Example 1, the rear surface transmission force was low. This is because in Comparative Example 1, the weave of the canvas appears as unevenness on the back surface of the belt, and the contact area between the pulley and the V-ribbed belt is narrowed to easily slip. This is because, since it is a woven fabric, no unevenness appears on the back surface of the belt, and the contact area between the pulley and the V-ribbed belt is widened to prevent slippage.

[0032]

[Table 1]

Further, as shown in FIG. 4, in the heat resistance running test, the V-ribbed belt A was mounted on the drive pulley 1 having a diameter of 120 mm.
5, the initial tension 8 of the V-ribbed belt A is hung on the driven pulley 16 having the same diameter and the tension pulley 17 having the diameter of 70 mm.
At 5 Kgf, the drive pulley 15 is rotated at a rotation speed of 3600 rpm, and a load of 10 PS is applied to the driven pulley 16, and the atmosphere 1
The time until the cracks are generated in the rib portion 3 of the V-ribbed belt A after running at 20 ° C. is shown by an index.

As a result, as shown in Table 1, the inventive examples were able to obtain the same thermal crack life as Comparative Examples 1 and 2.

Further, as shown in FIG. 5, the rolling resistance of the V-ribbed belt A is determined by applying the V-ribbed belt A to the drive pulley 18 having a diameter of 120 mm and the driven pulley 19 having the same diameter.
The initial tension of the ribbed belt A was 85 Kgf, and the belt peripheral speed was 70 m / sec. In the comparative examples 1 and 2, lateral blurring is observed, whereas in the example of the present invention, the inclination α of the warp yarns 6 of the back cloth 5 with respect to the belt width direction is almost equal to the spiral angle θ of the core wire 1 and thus is lateral It was a very smooth run without blurring.

Although not listed in Table 1 as data, in the present invention example, the excellent durability of the V-ribbed belt A was determined by specifying the density of the warp threads 6 and the weft threads 7 of the back cloth 5, and the orientation of the warp threads 6. Flex fatigue resistance can be obtained and it can be used with small pulleys.

[0037]

As described above, according to the present invention as set forth in claim 1, the back cloth is made of the woven fabric, and the warp thereof has no lower twist and upper twist is set to 3 to 10 times / 10 cm. Since the twisted yarn is used, the crack resistance can be improved by facilitating the impregnation property of the rubber into the fiber. Further, unlike the conventional case, the texture of the canvas does not appear as unevenness due to the back surface of the belt, and the wide contact area between the pulley and the V-ribbed belt can prevent slippage and improve the transmission capability during rear driving.

According to the present invention of claim 2, the warp density of the back cloth is set to 40 to 55 threads / 5 cm, and the weft density is set to 3 threads / 5 cm or less. Flexibility can be imparted.

According to the third aspect of the present invention, the bending fatigue resistance of the V-ribbed belt can be further improved by the warp threads of the back cloth extending in the belt width direction.

According to the present invention as set forth in claim 4, since the inclination of the warp of the back cloth with respect to the belt width direction is set to 0 to 10 °, V is adjusted according to the balance with the spiral angle of the core wire.
It is possible to prevent the ribbed belt from rolling over.

[Brief description of drawings]

FIG. 1 is a perspective view showing a part of a V-ribbed belt according to an embodiment of the present invention.

FIG. 2 is a plan view showing an orientation state of warp threads of a back cloth with respect to a V-ribbed belt.

FIG. 3 is an explanatory diagram illustrating a test procedure of a rear surface transmission capability of a V-ribbed belt.

FIG. 4 is an explanatory diagram illustrating a test procedure of a heat-resistant crack life of a V-ribbed belt.

FIG. 5 is an explanatory diagram for explaining a test procedure for rolling resistance of a V-ribbed belt.

[Explanation of symbols]

 1 core wire 2 adhesive rubber part 3 rib part 5 back cloth 6 warp 7 weft A V ribbed belt α inclination of warp with respect to belt width direction

Claims (4)

[Claims] 1. A plurality of V-shaped rib portions are provided on one surface of an adhesive rubber portion in which a plurality of core wires are embedded along the belt longitudinal direction, and a back cloth is provided on the other surface of the adhesive rubber portion. Is a V-ribbed belt, wherein the back cloth has no lower twist and upper twist is 3 to 10 times / 10.
A V-ribbed belt comprising a plurality of warp yarns set to cm and a plurality of weft yarns that connect the respective warp yarns at predetermined intervals in the longitudinal direction, and are woven. 2. The back cloth has a warp density of 40 to 55 yarns /
2. The V-ribbed belt according to claim 1, wherein the weft density is set to 5 cm and the weft density is set to 3 threads / 5 cm or less. 3. The V-ribbed belt according to claim 1, wherein the back cloth has a warp attached to the other surface of the adhesive rubber portion so as to extend along the belt width direction. 4. The warp of the back cloth is 0 in the belt width direction.
The V-ribbed belt according to claim 3, wherein the V-ribbed belt is oriented so as to have an inclination of -10 °.