JPH07269658A - V-ribbed belt - Google Patents

Abstract

PURPOSE:To prevent the bottom of V-rib grooves from longitudinally splitting while preventing a V-ribbed belt from the degradation of the transmitting capacity in the back face drive by changing a part of the construction of a tensile body layer of the V-ribbed belt. CONSTITUTION:A V-ribbed belt has a back face rubber layer 5 on the upper surface of an adhesive rubber layer 3 embedded with tensile body ropes 2 and is formed integrally with a plurality of V-rib layers 6 having short fibers 9 oriented widthwise of the belt and extending longitudinally of the belt on the lower surface. At least any one of the adhesive rubber layers between the back surface rubber layer 5, the V-rib layer 6 and the tensile body rope 2 disposed on the upper and lower surfaces of the tensile body rope layer 4 is embedded with monofilaments 7, 8 having a flat cross section with 1.5-10 of ratio of shorter diameter to longer diameter and juxterposed widthwise of the belt with the shorter diameter of the section positioned in alignment with the direction of height.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a V-ribbed belt, and more particularly to a V-ribbed belt having a rubber layer on the back surface of the V-ribbed belts used for general industry, automobiles, agricultural machinery and household appliances.

[0002]

2. Description of the Related Art V-ribbed belts, which are a type of power transmission belts, are thinner than V-belts and therefore have less bending stress, have a wide usable range for small pulleys, and can be designed compactly, and also have an energy-saving effect. It is remarkable. Further, compared to the V belt, the V ribbed belt has many advantages such as a decrease in the belt tension caused by the depression in the pulley groove at the time of driving, and thus a long belt life. It is expanding steadily for automobiles, agricultural machinery and home appliances.

By the way, this type of V-ribbed belt 10
Is a belt longitudinal direction in which short fibers 39 are oriented in the belt width direction inside a flat belt-shaped tensile body layer 34 in which a tensile body rope 32 is embedded in an adhesive rubber layer 33 as shown in FIG. A plurality of V-shaped rib portions 36 extending in the same direction are integrally formed, and the tensile body layer 34 is formed by laminating one or more layers of rubber-attached canvas on the back surface, or simply the rubber on the back surface. A structure in which the layer 35 is attached is known.

[0004]

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, a V-ribbed belt using a canvas on the back surface is not used. However, there is a problem that it easily slips and the power transmission capacity on the back is greatly reduced.

On the other hand, the V-ribbed belt using a rubber layer on the back side of the belt has improved power transmission ability on the back side, but on the other hand, it is vertically ripped due to pebbles being caught in the rib groove portion sandwiched by the V-ribs and misalignment. (Cracks in the belt longitudinal direction)
There is a problem that is likely to occur. Further, the belt of the back rubber layer requires a reinforcing material to prevent vertical cracking. However, if a canvas or a usual slack is added as a vertical crack preventing material, the belt becomes thick and the bending performance is deteriorated.

The present invention has been accomplished as a result of various investigations in order to solve these problems in view of the above-mentioned circumstances, and a rear drive is achieved by partially modifying the structure of the tension layer of the V-ribbed belt. It is intended to prevent the deterioration of the transmission ability at the time and to prevent the vertical tear that occurs in the groove portion between the V-shaped rib layers.

[0007]

In order to achieve the above object, a feature of the present invention is that a back rubber layer is provided on the upper surface of a tension layer in which a tension rope is embedded in an adhesive rubber layer, Further, in a V-ribbed belt integrally formed with a plurality of V-shaped rib layers having a short fiber group oriented in the belt width direction and extending in the belt longitudinal direction on the lower surface, a back rubber layer disposed on the upper surface and the lower surface of the tensile body layer, A monofilament having a flat cross-section having a ratio of major axis to minor axis of 1.5 to 10 is formed in the adhesive rubber layer of at least one of the V-shaped rib layer and the tensile body rope in the belt width direction. In addition, the V-ribbed belt is embedded in parallel so that the minor axis of the cross section thereof matches the height direction of the belt. The flat monofilament has a minor axis of 0.8 mm or less, and the back rubber layer needs to have a thickness of 0.3 to 5.0 mm. .

[0008]

The flat monofilament is aligned in the belt width direction and the minor axis of the cross section is aligned in the belt height direction in one or both of the upper and lower sides of the tension rope in the adhesive rubber layer of the V-ribbed belt. Since they are embedded in parallel, abnormal stress acts on the rib groove portion due to variations in the groove shape of the pulley, misalignment between the pulleys, inclusion of foreign matter between V-shaped rib layers, etc., causing partial cracking. Even if it occurs, its growth can be stopped.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. FIG. 1 is a partial cross-sectional perspective view of a V-ribbed belt according to the present invention, in which a V-ribbed belt main body 1 has a tensile member 2 made of a rope with low elongation and high strength such as polyester, nylon, aramid, carbon, and glass fiber. , SBR, CR, NBR, HNBR,
A flat belt-shaped tensile member layer 4 embedded in an adhesive rubber 3 made of a single material such as CSM or polyurethane or a blend thereof is arranged in the center, and the adhesive rubber is provided above the tensile member layer 4. A backside rubber layer 5 made of the same material as the layer 3 and a V-shaped rib layer 6 made of the same material as the adhesive rubber layer 3 are provided below the tensile body layer 4.

In the V-shaped rib layer 6 and the back rubber layer 5, if necessary, synthetic fiber yarns such as nylon, vinylon, polyester, and aromatic polyamide, or natural fiber yarns such as cotton and pulp are synthesized. A mixed yarn mixed with fiber yarn in a predetermined ratio, and a short fiber having a length of 3 to 10 mm is used as a rubber 10
It is the same as the conventional V-ribbed belt in that 5 to 30 parts by weight relative to 0 parts by weight are oriented and mixed in the belt width direction.

In the present invention, the monofilament 7 having a flat cross section is formed in the adhesive rubber layer 3 between the tensile body rope 2 in the tensile body layer 4, the back rubber layer 5 and the V-shaped rib layer 6. , 8 are lateral to the belt 1 and the monofilament 7,
A plurality of cross-sections of 8 are made to correspond to the height direction of the belt 1 and a plurality of them are embedded in parallel over the entire length of the belt. The flat shape of the monofilament has a ratio of major axis to minor axis of 1.5 to
It is in the range of 10, and the length of the minor axis is designed to be 0.8 mm or less.

As the material of the monofilaments 7 and 8, it is desirable to use a synthetic resin such as nylon, polyester, vinylon or aramid, or a mixture thereof. As described above, by using the flat monofilament, the vertical tear preventing material is inserted into the adhesive rubber layer 3 which is a small space between the back rubber layer 5 and the V-shaped rib layer 6 and the tensile member rope 2. Is possible.

Here, the reason why the ratio of the long diameter to the short diameter of the monofilament is limited to the range of 1.5 to 10 is that the ratio is 1.
When it is 5 or less, the length of the minor axis becomes larger than 0.8 mm, the thickness of the adhesive rubber layer 3 becomes thicker, and as a result, the thickness of the tensile body layer 4 becomes thicker and the flexibility of the belt is lowered. On the other hand, when the ratio is 10 or more, the monofilaments become too flat and the spacing between the monofilaments becomes narrow, resulting in difficulty in bending the belt, which is offset by the effect of making the thickness thin and easy to bend, and the life cannot be improved. It will be possible.

The thickness of the back rubber layer 5 is relatively thin, 0.3 to 5.0 mm, preferably 0.5 to 2.0 mm, so as not to affect the flexing life of the belt.
Here, if the thickness of the back rubber layer is less than 0.3 mm, sufficient resistance to vertical tearing of the belt cannot be obtained, and the thickness is 5.0
If it is more than mm, the thickness of the entire belt becomes too thick, which adversely affects the bending resistance. In the above embodiment, the V-shaped rib layer 6
And short fibers are oriented and mixed in the back rubber layer 5,
Needless to say, it is not necessary to mix short fibers as necessary.

FIG. 2 shows another embodiment of the present invention, in which the adhesive rubber layer 3 between the tensile body rope 2 of the tensile body layer 4'and the V-shaped rib layer 6 is provided.
This is the case where the flat monofilament 8 is inserted in the belt width direction. As a matter of course, the embedding position of the flat monofilament is that the adhesive rubber layer 3 between the tensile body rope 2 and the rear rubber layer 5 of the tensile body layer 4 ′ on the side opposite to FIG.
It goes without saying that it can be inside.

[0016]

Experimental Example Next, the V-ribbed belt 1'according to the present invention in which the monofilament 8 on the lower side of the V-ribbed belt 1 shown in FIG. 1 was removed and the conventional V-ribbed belt 31 shown in FIG. A specific experimental example of measuring the tear force will be described.

The experimental method is a K-shaped V-ribbed belt having four V-shaped rib peaks with a major axis of 1.65 mm and a minor axis of 0.22 mm.
And a nylon monofilament having a flat cross section with a ratio of major axis to minor axis of 7.5 is arranged in parallel on the upper side of the tensile body rope 2 so that the minor axis of the fold is aligned with the belt height direction. The two rib ridges of the V-ribbed belt embedded by the above method were gripped by two chucks, and the vertical tearing force was compared by pulling at a pulling speed of 50 mm / min with a tensile tester with the bottom of the rib groove as a boundary. still,
The thickness of the back rubber layer is 0.5 mm.

As a result, the belt according to the present invention has
160N (newton), the conventional belt is 38-40N
It was confirmed that the belt of the present invention had a vertical tear force of about 3.8 times that of the conventional belt.

[0019]

As described above, the V-ribbed belt according to the present invention has the following effects by inserting the flat monofilament in the adhesive rubber layer in the belt width direction. 1. It is possible to improve the transmission capability when driving the back surface and prevent vertical tearing between the V-shaped rib layers. 2. It is much easier to bend than a belt that uses canvas on the back surface, and it has a longer flex life and can be used with a smaller pulley diameter.

3. By using rubber on the back, you can remove the canvas joint, etc., and you can also polish it, making it possible to have a very uniform back and reduce blurring etc. 4. In the conventional belt, it was necessary to prepare three kinds of materials such as canvas, rope and rubber, but according to the present invention, only two kinds of rope and rubber are required, the equipment can be greatly reduced, and the process can be performed. It will be easy.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional perspective view of a V-ribbed belt according to the present invention.

FIG. 2 is a sectional view showing another embodiment of the V-ribbed belt according to the present invention.

FIG. 3 is a partial cross-sectional perspective view of a conventional V-ribbed belt having a rubber layer on the back surface.

[Explanation of symbols]

 1 V-ribbed belt 2 Tensile rope 3 Adhesive rubber layer 4 Tensile layer 5 Back rubber layer 6 V-shaped rib layer 7 Flat monofilament 8 Flat monofilament 9 Short fiber

Claims (3)

[Claims] 1. A back rubber layer is provided on the upper surface of a tensile body layer in which a tensile body rope is embedded in an adhesive rubber layer, and a plurality of short fiber groups extending in the belt longitudinal direction are oriented on the lower surface in the belt width direction. In the V-ribbed belt integrally formed with the V-shaped rib layer, the back rubber layer disposed on the upper surface and the lower surface of the tensile body layer, and at least one of the V-shaped rib layer and the tensile rope are bonded together. The ratio of major axis to minor axis is 1.5 in the rubber layer.
10. A V-ribbed belt in which monofilaments having a flat cross section of 10 are embedded in parallel in the belt width direction and in a manner that the minor axis of the cross section matches the height direction of the belt. 2. The flat monofilament has a minor axis of 0.
The V-ribbed belt according to claim 1, which is 8 mm or less. 3. The back rubber layer has a thickness of 0.3 to 5.0 mm.
The V-ribbed belt according to claim 1, wherein