JP2000018338A - Cogged v belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit early development of a crank inside a cog in the case where a high load is applied by providing a second bottom rubber layer of which a modulus of elasticity in a belt width direction is set to be bigger than that of a first bottom rubber layer on a belt inner surface side of the first bottom rubber layer approximately along a belt inner surface side of a cog. SOLUTION: A bottom rubber layer 2 comprises a first bottom rubber layer 2a provided on a belt back surface side and a second bottom rubber layer 2b on an inner surface side of the first bottom rubber layer 2a approximately along a belt inner surface side of a cog 5. A thickness of the second bottom rubber layer 2b is set to be 5-50% of a whole thickness of the bottom rubber layer 2. Further, the first and second bottom rubber layers 2a, 2b are constituted by the same rubber material each other and a short fiber 10 is mixed in the respective layers so as to extend in a belt width direction. Then, the short fiber 10 is mixed much more in the second bottom rubber layer 2b than in the first bottom rubber layer and a modulus of elasticity of a belt width direction in the second bottom rubber layer 2b is set to be bigger 1.5 times or more than that of the first bottom rubber layer 2a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of a cogged V belt in which a cog is formed on a bottom rubber layer.

[0002]

2. Description of the Related Art Generally, a cogged V-belt is provided with an upper rubber layer on the back side of the belt, a bottom rubber layer on the inner side of the belt, and between the upper rubber layer and the bottom rubber layer, and a core body embedded inside. It consists of an adhesive rubber layer. Cogs having a wavy shape in the belt length direction are formed on the inner surface of the bottom rubber layer on the inner side of the belt, and the cogs provide a reinforcing effect against lateral pressure from the pulley and a softening effect that is compatible with a relatively small pulley. ing. The back or inner surface of the cogged V-belt is usually covered with canvas.

[0003]

By the way, in the above-mentioned cogged V belt, if it is used for a long time under light load,
Due to the thermal deterioration of the rubber, cracks occur in the belt thickness direction from the cog bottom (the portion connecting adjacent cog side surfaces of adjacent cogs) to the vicinity of the core, so that further use is impossible.

However, when a high load acts, such as a two-wheel transmission belt with a large displacement, unlike when the load is light, breakage occurs early before the rubber is thermally degraded. There's a problem. That is, as shown in FIG. 4, a crack f is generated substantially along the side surface near the front side surface in the belt traveling direction inside the cog e. The crack f generated inside the cog e initially occurs near the side surface of the cog e. However, if the belt is used as it is, it also occurs at the center side of the cog e in the belt length direction. This is because the cog e is slightly delayed behind the core c in the belt advancing direction at the portion wound around the pulley of the belt, so that a force that sways in the belt length direction is repeatedly applied to the cog e. Conceivable. In FIG. 4, a is an upper rubber layer, and b is an upper rubber layer.
Is a bottom rubber layer, and d is an adhesive rubber layer.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the configuration of a bottom rubber layer for a cogged V belt having a bottom rubber layer formed with cogs. Accordingly, it is an object of the present invention to suppress early generation of cracks in a cog when a high load acts, and to improve the life of the cog.

[0006]

In order to achieve the above object, according to the first aspect of the present invention, on the premise of a cogged V belt in which a cog is formed on a bottom rubber layer, the bottom rubber layer is formed of a first rubber layer.
And the first rubber layer is provided on the inner surface side of the belt of the first rubber layer so as to be substantially along the inner surface of the cog and has a greater elastic modulus in the belt width direction than the first rubber layer. And a second bottom rubber layer.

With the above structure, the cog is hardly deformed in the belt width direction even when the cog receives a considerably large lateral pressure from the pulley in the portion wound around the pulley by the second rubber layer having a high elastic modulus, As a result, the cog is also restrained in the belt length direction and is less likely to be shaken in the belt length direction. For this reason, generation of cracks inside the cog can be suppressed. In addition, since the second bottom rubber layer is provided substantially along the inner surface of the cog on the inner side of the belt, it is possible to prevent the flexibility of the belt from being deteriorated by appropriately setting its thickness. . Therefore, when a high load acts on the belt, it is possible to improve the life of the belt while maintaining good flexibility of the belt.

According to a second aspect of the present invention, in the first aspect of the invention, the elastic modulus in the belt width direction of the second bottom rubber layer is set to be 1.5 times or more that of the first bottom rubber layer. And Thus, a preferable form is obtained from the viewpoint of extending the life of the belt.

According to the third aspect of the present invention, assuming that a cogged V belt having a cog formed on the bottom rubber layer, the bottom rubber layer includes a first bottom rubber layer and an inner surface of the belt of the first bottom rubber layer. And a second bottom rubber layer provided substantially along the inner surface of the cog on the inner side of the belt and having a rubber hardness in the belt width direction larger than the first bottom rubber layer.

According to the present invention, similarly to the case where the elastic modulus is increased, the movement of the cog in the belt length direction can be restrained. Therefore, the same function and effect as the first aspect of the invention can be obtained.

According to a fourth aspect of the present invention, in the third aspect of the present invention, the number of cross-linking points of the second bottom rubber layer is set to be larger than that of the first bottom rubber layer. This allows
The number of crosslinking points can be adjusted by adding a crosslinking agent,
As a result, the rubber hardness of the second rubber bottom layer can be easily made larger than that of the first rubber bottom layer.

According to the fifth aspect of the present invention, the first, second or third aspect of the present invention is provided.
In the invention, the rubber material of the second bottom rubber layer is different from that of the first bottom rubber layer. By doing so, the elastic modulus or rubber hardness of the second rubber bottom layer can be easily made larger than that of the first rubber bottom layer.

[0013] In the invention of claim 6, on the premise of a cogged V-belt in which cogs are formed on the bottom rubber layer, the bottom rubber layer has a first bottom rubber in which short fibers are mixed so as to extend in the belt width direction. The first bottom rubber layer is provided on the inner surface side of the belt so as to substantially extend along the inner surface of the cog, and the short fibers extend in the belt length direction substantially along the inner surface of the cog. And a second bottom rubber layer mixed with the second rubber layer.

According to the present invention, even if the elastic modulus or rubber hardness in the belt width direction of the second bottom rubber layer is not made larger than that of the first bottom rubber layer, the short fibers in the second bottom rubber layer can be used. The movement of the cog in the belt length direction can be effectively restrained. Therefore, also in the present invention, claim 1 or 3
The same operation and effect as described above can be obtained.

[0015]

(Embodiment 1) FIG. 1 shows a cogged V-belt B according to Embodiment 1 of the present invention. The cogged V-belt B has an upper rubber layer 1 provided on a belt rear surface, and
It comprises a bottom rubber layer 2 provided on the inner surface of the belt, and an adhesive rubber layer 4 provided between the upper rubber layer 1 and the bottom rubber layer 2. Inside the adhesive rubber layer 4, cores 3 extending in the belt length direction are embedded at a predetermined pitch in the belt width direction. Cogs 5, 5,... Having a wavy shape in the belt length direction are formed on the inner surface of the bottom rubber layer 2 on the inner side of the belt. The rear surface (the belt rear surface of the upper rubber layer 1) and the inner surface (the inner surface of the cogs 5, 5,... Of the belt) of the cogged V belt B are covered with an upper canvas 6 and a bottom canvas 7, respectively.

The bottom rubber layer 2 has a first bottom rubber layer 2a provided on the back side of the belt and a belt inner surface of the cogs 5, 5,... On the inner side of the belt of the first bottom rubber layer 2a. And a second rubber bottom layer 2b provided substantially along the surface. The thickness of the second bottom rubber layer 2b is
It is set to 5 to 50% of the whole.

The first and second bottom rubber layers 2a and 2b are made of the same rubber material (chloroprene rubber or the like), and short fibers 10 and 10 are contained in the first and second bottom rubber layers 2a and 2b. Are mixed so as to extend in the belt width direction. And these short fibers 10, 10, ...
Is mixed into the second rubber bottom layer 2b more than the first rubber bottom layer 2a, and the elastic modulus in the belt width direction of the second rubber bottom layer 2b is 1 more than that of the first rubber bottom layer 2a. .5 times or more.

When the cogged V-belt B is used in a situation where a high load acts as a two-wheel transmission belt or the like having a high displacement, the second bottom rubber layer 2b having a high elastic modulus causes the belt B to pulley. Even if each cog 5 receives a considerably large lateral pressure from the pulley in the wound portion, it becomes difficult to deform in the belt width direction. As a result, each cog 5 is also restrained in the belt length direction, and the movement of each cog 5 in the belt length direction is reduced. For this reason, generation of cracks in each cog 5 can be suppressed. Further, the second bottom rubber layer 2b is provided substantially along the inner surface of the belt of each cog 5 and its thickness is set to 5 to 50% of the entire bottom rubber layer 2, so that the belt B The flexibility is hardly different from the conventional one. Therefore, even if a high load acts on the belt B, it is possible to improve the life of the belt while maintaining good flexibility of the belt.

In the first embodiment, the first and second bottom rubber layers 2a and 2b are made of the same rubber material. However, the rubber material of the second bottom rubber layer 2b is replaced with the first bottom rubber layer 2a. You may make it different. In this case, the rubber material of the second bottom rubber layer 2b is EPDM, alkylated chlorosulfonated polyethylene (ACSM), hydrogenated nitrile rubber (H-NB).
R) and H-NBR to which an unsaturated carboxylate (a metal salt such as zinc methacrylate or zinc acrylate) is added and crosslinked with an organic peroxide are suitable.

In the first embodiment, the elastic modulus in the belt width direction of the second bottom rubber layer 2b is set larger than that of the first bottom rubber layer 2a. The rubber hardness in the direction may be set to be larger than that of the first bottom rubber layer 2a. That is, a crosslinking agent such as thioureas or N, N'-m-phenylenedimaleimide is added to the second bottom rubber layer 2b to reduce the number of crosslinking points to the first.
Or more than the bottom rubber layer 2a of the second bottom rubber layer 2b.
The amount of the rubber reinforcing agent such as carbon black in the above may be larger than that of the first bottom rubber layer 2a. Also,
As described above, the rubber materials of the first and second rubber bottom layers 2a and 2b may be different from each other.

(Embodiment 2) FIG. 2 shows Embodiment 2 of the present invention.
(Note that the same parts as in FIG. 1 are denoted by the same reference numerals and detailed description thereof is omitted), and the orientation of each short fiber 10 in the second rubber bottom layer is different from that in the first embodiment. Things.

That is, in this embodiment, the short fibers 10, 10,... In the second rubber bottom layer 2b are cogs 5, 5,.
Along the belt inner side surface in the belt length direction (hereinafter, referred to as
(Referred to as a cog formation direction).

Therefore, in the second embodiment, unlike the first embodiment, the elastic modulus or rubber hardness in the belt width direction of the second bottom rubber layer 2b does not need to be larger than that of the first bottom rubber layer 2a. Also, short fibers 1 oriented in the cog forming direction
.., The movement of each cog 5 in the belt length direction can be effectively restrained. Therefore, the first embodiment
The same operation and effect as described above can be obtained.

[0024]

Next, a specific embodiment will be described. First, a cogged V belt corresponding to the first embodiment was manufactured (Examples 1 and 2). That is, by adjusting the amount of short fibers mixed, the elastic modulus in the belt width direction of the second bottom rubber layer is 3.5 times that of the first bottom rubber layer in the first embodiment, and 1.75 in the second embodiment. Each was set to double. Also, the second
The short fiber of the bottom rubber layer of the belt length direction (cog forming direction)
And a cogged V-belt corresponding to the second embodiment was produced (Example 3). Further, a cogged V-belt in which the rubber hardness in the belt width direction of the second rubber bottom layer was set to be larger than that of the first rubber bottom layer (Example 4). That is, the rubber hardness in the belt width direction of the first bottom rubber layer (the same as in Examples 1 to 3) is Hs (JIS A) =
The second bottom rubber layer has a Hs (JIS A) = 89 ° by adjusting the blending amount of carbon black or the like.
And Then, for comparison, the same cogged V belt as the related art without the second bottom rubber layer was produced (Comparative Example). still,
In Examples 1 to 4 and Comparative Example, the same material was used except for the second rubber bottom layer (specific materials and the like are shown in Table 1).
reference). In Table 1, the values of the elastic modulus and the rubber hardness are all in the belt width direction.

Next, a durability test was performed on each of the cogged V belts of Examples 1 to 4 and Comparative Example. That is,
As shown in FIG. 3, each of the belts 21 has a pulley diameter of 1
It is wound around a 10 mm drive pulley 22 and a driven pulley 23 having a pulley diameter of 120 mm, and a tensile load DW (DW = 120 kgf (1176 N)) is applied to each belt 21, while the driven pulley 23 is 4.5 kgf · m. (44.1
N.m), the drive pulley 22 is
The cog was rotated at 0 rpm (53.3 1 / s), and the time until cracks occurred inside the cog was examined. Each belt 21 has a length of 950 mm, an upper width of 23 mm, and a thickness of 10.5.
mm and a V angle of 30 ° were used, and the ambient temperature was room temperature.

Table 1 shows the results of the durability test. From this, each of the cogged V belts of Examples 1 to 4 and the comparative example has a crack due to the occurrence of a crack inside the cog, and the life is shorter in Examples 1 to 4 than that of the comparative example. It can be seen that the effect becomes remarkable when the elastic modulus in the belt width direction of the second rubber bottom layer is set to be considerably larger than that of the first rubber bottom layer.

[0027]

[Table 1]

[0028]

As described above, according to the first aspect of the present invention, for a cogged V-belt in which a cog is formed on a bottom rubber layer, the bottom rubber layer is formed by the first bottom rubber layer and the second bottom rubber layer. A second bottom rubber layer provided on the inner side of the bottom rubber layer of the first rubber layer so as to be substantially along the inner surface of the cog and having an elastic modulus in a belt width direction larger than that of the first bottom rubber layer; It consisted of: According to the third aspect of the invention, the bottom rubber layer is formed of the first rubber.
And a rubber rubber in the belt width direction which is provided substantially along the belt inner surface of the cog on the belt inner surface side of the first rubber layer, and has a greater rubber hardness in the belt width direction than the first rubber layer. A second bottom rubber layer was set. Further, in the invention of claim 6, the bottom rubber layer includes a first bottom rubber layer in which short fibers are mixed so as to extend in the belt width direction, and the cog on the inner side of the belt of the first bottom rubber layer. The second rubber layer was provided so as to extend substantially along the inner surface of the belt and mixed with short fibers so as to extend in the belt length direction substantially along the inner surface of the cog. Therefore, according to these inventions, it is possible to suppress the occurrence of cracks inside the cog at the time of a high load and to improve the life of the belt while maintaining the flexibility of the belt satisfactorily.

According to the second aspect of the present invention, the belt has a longer service life by setting the elastic modulus in the belt width direction of the second bottom rubber layer to be 1.5 times or more that of the first bottom rubber layer. A preferable form is obtained from the viewpoint of achieving.

According to the fourth aspect of the present invention, the number of cross-linking points of the second bottom rubber layer is set larger than that of the first bottom rubber layer, so that the rubber hardness of the second bottom rubber layer can be easily increased. It can be larger than the first rubber bottom layer.

According to the fifth aspect of the present invention, the rubber material of the second bottom rubber layer is different from that of the first bottom rubber layer.
The elastic modulus or rubber hardness of the second bottom rubber layer can be easily made larger than that of the first bottom rubber layer.

[Brief description of the drawings]

FIG. 1 is a sectional perspective view showing a cogged V belt according to a first embodiment of the present invention.

FIG. 2 is a diagram corresponding to FIG. 1 showing a second embodiment.

FIG. 3 is a schematic diagram showing a procedure of a durability test.

FIG. 4 is a side view of a conventional cogged V-belt showing a crack generated when a high load acts.

[Explanation of symbols]

 B Cogged V belt 2 Bottom rubber layer 2a First bottom rubber layer 2b Second bottom rubber layer 5 Cog 10 Short fiber

Claims (6)

[Claims] 1. A cogged V-belt in which a cog is formed on a bottom rubber layer, wherein the bottom rubber layer has a first bottom rubber layer and a belt inner surface of the cog on a belt inner surface side of the first bottom rubber layer. A cogged V-belt comprising: a second bottom rubber layer provided substantially along a side surface and having an elastic modulus in a belt width direction set to be larger than the first bottom rubber layer. 2. The cogged V-belt according to claim 1, wherein the elastic modulus in the belt width direction of the second rubber bottom layer is the first elastic modulus.
A cogged V-belt, which is set to be at least 1.5 times the bottom rubber layer. 3. A cogged V-belt in which a cog is formed on a bottom rubber layer, wherein the bottom rubber layer has a first bottom rubber layer and a belt inner surface of the cog on a belt inner surface side of the first bottom rubber layer. A cogged V-belt comprising a second bottom rubber layer provided substantially along the side surface and having a rubber hardness in the belt width direction larger than the first bottom rubber layer. 4. The cogged V belt according to claim 3, wherein the number of cross-linking points of the second bottom rubber layer is set to be larger than that of the first bottom rubber layer. 5. The cogged V belt according to claim 1, wherein the rubber material of the second bottom rubber layer is different from that of the first bottom rubber layer. 6. A cogged V belt in which cogs are formed on a bottom rubber layer, wherein the bottom rubber layer comprises: a first bottom rubber layer in which short fibers are mixed so as to extend in a belt width direction; A second fiber provided on the inner surface of the bottom rubber layer along the inner surface of the cog so as to substantially extend along the inner surface of the cog; and a short fiber mixed so as to extend in the belt length direction substantially along the inner surface of the cog. A cogged V-belt comprising a bottom rubber layer.