JP2000227144A - Transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of belt noise by increasing the wear resistance of a belt side face, the cracking resistance of a cover canvas and belt durability even during the traveling of the belt under the condition of a high- temperature load in a V belt having a low edge cog wherein an elongation rubber layer is disposed in the backside of a core wire, a compression rubber layer is disposed in a bottom surface, a number of cogs are formed to be arrayed in the longitudinal direction of the belt, and the cover hood of at least one or more plies adhered to the bottom surface of the compression rubber layer. SOLUTION: A cover canvas 9 is made of warp 10 and weft 11 crossing at 80 to 100 deg., and weft 11 contains at least an elastic bulky processed thread, an urethane elastic thread or a rubber elastic thread to have elasticity. This cover canvas 9 is adhered to the bottom surface of a compression rubber layer 4 such that a crossing angle α of the warp 10 with a belt width direction W is set at α=8 to 30 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission belt, and more particularly, to a technical field of a cogged V-belt having a plurality of cogs on a bottom surface.

[0002]

2. Description of the Related Art Today, a V-belt with a low-edge cog is generally used as a V-belt for an automobile. This belt has a core wire composed of a low-strength, high-strength rope embedded in an adhesive rubber layer, and short fibers are oriented in the belt width direction on the bottom surface side (lower side) of the adhesive rubber layer. A compressed rubber layer is provided on the back side (upper side) of the belt, and a canvas with rubber is laminated and integrated on each surface of the compressed rubber layer and the extended rubber layer.

[0003] This type of belt has a higher transmission capacity because of a higher coefficient of friction than a wrapped belt in which the entire belt is wrapped with a canvas with rubber, and the lateral pressure resistance of the compressed rubber layer in the pulley groove is reduced. It has characteristics of being large and small in deformation.

The qualities required for the low-edge cog type V-belt include (1) low noise during belt driving, (2) high lateral pressure resistance and long life of the belt, and (3) belt. The slip is small,
(4) The belt has good flexibility and a long service life, and the belt having such characteristics is widely used as a transmission belt for a high-load vehicle.

[0005] Among the belt components constituting the belt,
As the cover canvas attached to the surface (bottom surface) of the compressed rubber layer, cotton, nylon, polyester, aramid, etc. were used as warps extending in the belt width direction, and woolly nylon or urethane elastic yarn was included to form a cog. A canvas in which the stretchable yarn is a weft in the belt length direction, or a bias canvas in which cotton, nylon, polyester, aramid or the like is used as a warp and a weft; It has been proposed to use (see Utility Model Registration No. 2584618).

[0006]

The conventional cogged V-belt has the following problems. That is,
As shown in FIG. 11, as the cover canvas b of the belt a, for example, a nylon filament yarn is used for the warp c in the belt width direction, and a nylon which has elasticity in the longitudinal direction of the belt to give a cog shape to the weft yarn d. When wooly yarn is used, when the belt a is run under high temperature and high load conditions, the temperature of the side of the belt rises due to the slip and side pressure of the belt a, and particularly the temperature of the bottom of the cog e where stress tends to concentrate. And the cracks occur at the bottom of the cog, shortening the life of the belt.

Further, since the warp c of the cover canvas b is arranged in the belt width direction, as shown in FIG. 12, the warp c has a substantially circular shape with respect to the side surface (cut surface at the time of manufacture) of the belt a. However, the weft yarn d that is substantially parallel to the cut surface comes to have an irregular cross-sectional shape, and it is difficult to increase the area occupied by the fibers in the cut surface. Therefore, as shown in FIG. 13, when the belt a comes into contact with the groove f1 of the pulley f, the kinetic friction coefficient (μ ′) of the belt a becomes large and the squeal of the belt a may occur.

The present invention has been made in view of the above points, and an object of the present invention is to improve the structure of the bottom cover canvas in the V-belt with a transmission cog as described above to improve the belt. Even when running under high temperature and high load conditions, the abrasion resistance of the belt side, the crack resistance of the cover canvas,
An object of the present invention is to enhance belt durability and reduce belt noise.

[0009]

In order to achieve the above object, according to the present invention, a cover canvas is attached to the bottom surface of a belt so that the crossing angle of the warp with the belt width direction is 8 to 30 degrees. And

More specifically, in the first aspect of the present invention, an extension layer is disposed on the back side (upper side) of the core wire and a compression layer is disposed on the bottom side (lower side) of the belt, and the compression layer has a belt. It is premised on a transmission belt in which a large number of cogs extending in the width direction are formed side by side in the belt length direction, and at least one ply of cover canvas is adhered to the bottom surface of the compression layer.

The cover canvas is made of a woven fabric in which the angle between the warp and the weft is 80 to 100 °, and the weft has elasticity. In this cover canvas, the crossing angle α of the warp with the belt width direction is α.
= 8 to 30 °, which is characterized in that it is attached to the bottom surface of the compression layer.

If the crossover angle α of the warp in the cover canvas with the belt width direction is less than α = 8 °, the effect of lowering the noise of the belt is insufficient, whereas if α = 30 °, cogging occurs. Α = 8 ° to 30 ° because the tooth properties are deteriorated, the flexibility of the belt is reduced, and the life of the belt is shortened.

With the above construction, the cover canvas is stuck diagonally by the intersection angle α (= 8 to 30 °) between the warp and the belt width direction, so that the canvas is exposed on the side surface (cut surface) of the belt. Of the conventional warp and weft yarns (α = 0
°), the cut cross-sectional area of the warp and weft yarns increases, and the exposed area of the fiber on the side surface of the belt increases. Therefore, the coefficient of kinetic friction on the side surface of the belt is kept low, and the squeal of the belt when the belt hits the bottom of the pulley groove can be prevented.

Further, since the cover canvas is affixed obliquely in a substantially biased manner, even if the cracks generated at the cog bottom are to be expanded in the belt width direction along the cog bottom, the yarn existing in the expansion direction is required. Is increased by the warp, and the cracks need to be enlarged while cutting the increased yarn. Thereby, the crack growth can be suppressed and the crack resistance can be increased.

In the second aspect of the present invention, the weft of the cover canvas includes at least one of a stretchy bulky yarn, a urethane elastic yarn and a rubber elastic yarn. This makes it possible to easily obtain desired wefts of the cover canvas attached to the belt.

[0016]

FIG. 2 shows a cogged V-belt B as a power transmission belt according to an embodiment of the present invention. This belt B is composed of NR, SBR, CR, H-NBR, H-NBR and zinc methacrylate. A mixture of ACSM, EPDM, E
It has an adhesive rubber layer 1, an extended rubber layer 3, and a compressed rubber layer 4 made of a rubber material such as PM alone or a mixture thereof. A core wire 2 made of PET, PEN, aramid, glass or the like and having a low elongation and high strength is spirally embedded in the adhesive rubber layer 1. The layer 3 and the compressed rubber layer 4 are integrally laminated on the belt bottom side (lower side). This compressed rubber layer 4
Polyamide, polyester, vinylon, aramid,
Are oriented and mixed in the belt width direction W, and a number of cogs 6, 6,... Extending in the belt width direction W are provided at the bottom of the compressed rubber layer 4. They are formed side by side at regular intervals in the vertical direction.

A back cover canvas 8 is adhered to the back surface of the stretched rubber layer 3 and at least one bottom cover canvas 9 is adhered to the bottom surface of the compressed rubber layer 4 to be laminated and integrated.

The feature of the present invention resides in the above-mentioned bottom cover canvas 9. That is, the bottom cover canvas 9 is formed of the warp 10
And a single-woven fabric such as a plain weave, a twill weave, and a satin weave made of the weft 11, and the angle β formed by the warp 10 and the weft 11 is β = 80 to 100 °. The warp 10 is
For example, a filament or spun yarn made of nylon, polyester, cotton, aramid, vinylon, PBO or the like is used. On the other hand, as the weft 11, a stretchable yarn containing at least one of stretchable bulky yarn, urethane elastic yarn and rubber elastic yarn is used. The bottom-side cover canvas 9 is subjected to an adhesive treatment such as a resin adhesive such as RFL, epoxy, and isocyanate, or a rubber treatment such as rubberization and friction. The adhesive treatment is applied to the bottom surface of the compressed rubber layer 4. Is being worn.

As shown in FIG. 1, the bottom cover canvas 9 is attached to the bottom surface of the compressed rubber layer 4 such that the crossing angle α of the warp 10 with the belt width direction W is α = 8 to 30 °. Is being worn.

Therefore, in this embodiment, the bottom cover canvas 9 adhered to the bottom surface of the compressed rubber layer 4 of the belt B has a crossing angle α between the warp 10 and the belt width direction W.
(= 8 to 30 °), so that FIG.
As shown in FIG. 12, the fiber portions of the warp yarns 10 and the weft yarns 11 of the cover canvas 9 exposed on the side surface of the belt B are increased more than when α = 0 ° (see FIG. 12), and the cut sectional areas of the warp yarns 10 and the weft yarns 11 are shown. And the exposed area of the fiber on the side surface of the belt B increases. As a result, the coefficient of dynamic friction on the side surface of the belt B is kept low, and the squeal of the belt B when the belt B hits the bottom of the pulley groove can be prevented.

Since the cover canvas 9 is adhered in a substantially biased shape, a crack C generated at the bottom of the cog 6 causes a belt width along the cog bottom as shown by a virtual line in FIG. Even if an attempt is made to expand in the direction W, the number of yarns existing in the expansion direction increases by the warp 10 compared to the conventional art, and the crack C needs to expand while cutting the increased yarn. By such a cutting resistance of the yarn, it is possible to suppress the expansion and growth of the crack C and increase the crack resistance.

[0022]

Next, a specific embodiment will be described. Teijin's Conex 30th was used for the warp yarns forming the cover canvas. On the other hand, the weft has a double covering structure, and the core yarn is spandex 420D.
And Teijin Technora 200D for the intermediate yarn, and 66 Woolly nylon 280 from Asahi Kasei for the outer yarn.
D was used as the yarn. After weaving these with a 2/2 twill weave, shrinkage processing was performed with a circular machine. After subjecting such canvas to RFL dip treatment, rubber was coated only on the adhesive surface to obtain a cover canvas. Table 1 shows the structure of the cover canvas.

Back surface (upper surface) of the belt using the above cover cloth
Width 30mm, circumference length 1000mm, pulley groove angle 24
A cogged V-belt having an angle of 11 mm, a thickness of 11 mm, and a cog height of 4.5 mm was produced. A chloroprene rubber composition was used for the compression rubber layer, the adhesive rubber layer, and the extension rubber layer, and a rope made of polyester fiber was used as a core wire.
Then, the two-ply cover canvas was attached to the bottom surface of the compressed rubber layer, and the crossing angle α of the warp with the belt width direction at that time was changed in the range of α = 8 to 30 °, and Examples 1 to 3 were used. did.

The crossing angle α of the warp of the cover canvas attached to the bottom surface of the compressed rubber layer with the belt width direction is α = 0 °,
5 ° and 45 ° are Comparative Examples 1 to 3, respectively. Comparative Example 1 is a conventional example. Further, as Comparative Example 4,
An angle β at which the weft and the warp intersect is a cover canvas in which β = 120 °, and the canvas intersects the warp with the belt width direction α.
Was attached so that α = 30. The back side cover canvas to be adhered to the back side of the belt of the stretched rubber layer was a 2-ply bias-shaped canvas made of cotton.

The belts obtained as described above were tested for cog shape (toothing performance), belt running life, dynamic friction coefficient, and belt squeal. Fig. 4
As shown in the figure, the belt B is wound between the driving and driven pulleys 14 and 15 having a pulley diameter of 125 mm and the intermediate pulley 16 having a pulley diameter of 70 mm such that the angle between the belt pull-in and the belt entrance and exit sides with respect to the intermediate pulley 16 is 90 °. , Intermediate pulley 16
To the drive pulley 14 by 1
The belt B was run by driving the driven pulley 15 at 4900 rpm while maintaining 100 ° C. with a driving torque of 0 PS.

In the dynamic friction test, as shown in FIG. 5, the cut and developed belt B is hung on a pulley 18 having a pulley diameter of 70 mm, and one end of the belt B is horizontally extended to load cell 1
At the same time, the other end is suspended from the pulley 18 to suspend a weight 21 of 1.0 kgf, and the pulley 18 is rotated at 30 rpm in a direction in which the belt B is fed to the weight 21 side. The dynamic friction coefficient μ ′ was calculated from the detected load F (kgf) of the load cell 19 at this time based on the following equation. μ ′ = (π / 2) · ln (F / 1.0)

Further, in the belt squealing test, as shown in FIG. 6, the belt B is wound around a driving pulley 23 having a pulley diameter of 140 mm and a driven pulley 24 having a pulley diameter of 70 mm, and the driven pulley 24 is in a no-load state. , Drive pulley 23
Was driven at 7000 rpm to run the belt B, and the sound generated at the belt exit side of the driving pulley 23 was measured by the sound meter 25.

The results of the above tests are shown in Table 1 below and FIGS.
This is shown in FIG. In addition, each evaluation value of the cog bottom crack running life and the dynamic friction coefficient is represented as a value when Comparative Example 1 (conventional example) is set to “100”. 7 to 10 show only Examples 1 to 3 and Comparative Examples 1 to 3, and Comparative Example 4 is not shown.

[0029]

[Table 1]

Considering Table 1 and FIGS. 7 to 10, the following can be understood. (1) With respect to the cogging protruding property, when the crossing angle α between the warp and the belt width direction in the canvas becomes α = 30 °, the cog height becomes slightly higher than the allowable cog height of 4 mm. Therefore, α> 30
In the case of °, there is no cog, and there is no problem in the cog height if 0 ≦ α ≦ 30 °. (2) Belt squeal is poor when the crossing angle α between the warp and the belt width direction in the canvas is 0 ≦ α <8 °, and a good result is obtained when 8 ≦ α ≦ 30 °. A similar tendency exists for the dynamic friction coefficient μ ′. (3) The running life can be improved by increasing the intersection angle α. The reason for this is that when the canvas is attached in a biased manner, the number of contact points of the yarn in the width direction of the canvas increases, and the growth of cracks running in the width direction of the belt can be inhibited. However, if α> 30 °, the cogging propensity will deteriorate and the flexibility of the belt will decrease, resulting in a reduction in the life of the belt. (4) When the canvas is stuck in a biased manner as in Comparative Examples 3 and 4, the non-stretchable warp shifts in the longitudinal direction of the belt and the cogging protruding property is alienated. Is difficult to use.

As described above, the effect of the present invention is obtained by attaching the cover canvas to the bottom surface of the compressed rubber layer such that the crossing angle α of the warp of the cover canvas with the belt width direction is α = 8 to 30 °. It is found to be effective. In particular, it is preferable that the optimum value of the crossing angle α is set to α = 15 °.

[0032]

As described above, according to the first aspect of the present invention, in the transmission belt of the cog type having at least one ply of cover canvas adhered to the bottom surface of the compression layer, the cover canvas has the following features. As a woven fabric in which the angle between the stretchable weft and the warp is 80 to 100 °, the cover canvas is placed on the bottom surface of the compression layer such that the crossing angle of the warp with the belt width direction is 8 to 30 °. By attaching the belt, the cut cross-sectional area of the warp and weft of the cover canvas exposed on the side of the belt can be increased, the exposed area of the fiber can be increased, and the coefficient of kinetic friction on the side of the belt can be kept low. In addition to preventing belt squeal in the event of a hit, the cover canvas attached in a substantially biased shape suppresses the growth and growth of cracks generated at the bottom of the cog and increases crack resistance. Therefore, the abrasion resistance of the side surface of the belt under high temperature and high load conditions, the crack resistance of the cover canvas, the improvement of the belt durability, and the low noise of the belt can be achieved.

According to the second aspect of the present invention, the weft of the cover canvas includes at least one of a stretchy and bulky processed yarn, a urethane elastic yarn and a rubber elastic yarn. Obtained easily.

[Brief description of the drawings]

FIG. 1 is a plan view of a cogged V-belt according to an embodiment of the present invention as viewed from a bottom surface side.

FIG. 2 is a perspective view of a cogged V-belt according to the embodiment of the present invention.

FIG. 3 is a side view showing a warp and a weft appearing on the side surface of the cogged V-belt according to the embodiment of the present invention.

FIG. 4 is a diagram schematically showing a belt running test device.

FIG. 5 is a view schematically showing a belt dynamic friction test apparatus.

FIG. 6 is a diagram schematically showing a belt squeal test apparatus.

FIG. 7 is a graph showing the results of cog bottom crack life characteristics with respect to the crossing angle between the warp of the cover canvas and the belt width direction in the belt.

FIG. 8 is a diagram showing the results of the characteristics of the cog height with respect to the crossing angle between the warp of the cover canvas and the belt width direction in the belt.

FIG. 9 is a graph showing the results of characteristics of the dynamic friction coefficient with respect to the crossing angle between the warp of the cover canvas and the belt width direction in the belt.

FIG. 10 is a diagram showing a result of noise characteristics with respect to an intersecting angle between a warp of a cover canvas and a belt width direction in a belt.

FIG. 11 is a plan view showing a cover canvas in a conventional cogged V-belt.

FIG. 12 is a diagram corresponding to FIG. 3 showing a state of warp and weft appearing on the side surface of a conventional cogged V-belt.

FIG. 13 is a cross-sectional view showing a state in which the cogged V-belt has a bottom contact with a pulley groove.

[Explanation of symbols]

 B V-belt with cog (transmission belt) 1 Adhesive rubber layer 2 Core wire 3 Elongated rubber layer 4 Compressed rubber layer 6 Cog 9 Bottom side cover canvas 10 Warp 11 Weft α Crossing angle of warp with belt width direction β Warp and weft Angle formed W Belt width direction

Claims (2)

[Claims] An elongated layer is provided on the back side of the core wire and a compression layer is provided on the bottom side of the belt, and a number of cogs extending in the width direction of the belt are formed on the compression layer side by side in the belt length direction. In a power transmission belt having at least one ply of cover canvas adhered to the bottom surface of the compression layer, the cover canvas has an angle of 80 to 1 between the warp and the weft.
It is made of a woven fabric that is 00 °, the weft has elasticity, and the cover canvas is attached to the bottom surface of the compression layer so that the crossing angle of the warp with the belt width direction is 8 to 30 °. A power transmission belt, characterized in that: 2. The power transmission belt according to claim 1, wherein the weft of the cover canvas includes at least one of a stretchy bulky yarn, a urethane elastic yarn and a rubber elastic yarn.