JP2003329088A - Double cogged V belt - Google Patents

Abstract

(57) [Problem] To provide a double cogged V-belt excellent in bending fatigue resistance. A double cogged V-belt (B) has an endless core embedded portion (10) having cores (12) embedded so as to form a spiral with a predetermined pitch in the belt width direction, and an inner peripheral side of the core embedded portion (10). Lower cog forming part 2 provided with lower cogs 24 formed at a constant pitch along the longitudinal direction of the belt
0, and an upper cog forming portion 30 provided on the outer peripheral side of the core wire embedding portion 10 and having an upper cog 34 formed at a constant pitch along the longitudinal direction of the belt. The distance from the bottom of the groove 25 extending in the belt width direction between the adjacent lower cogs 24 to the core wire is 2.0 to 3.0 mm, and / or the belt width between the upper cogs 34 adjacent to each other. Groove 35 extending in the direction
The distance from the bottom to the cord is 1.2 to 2.0 mm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an endless core wire embedded portion having core wires embedded so as to form a spiral having a predetermined pitch in the belt width direction, and a belt provided on the outer peripheral side of the core wire embedded portion. An upper cog forming portion having an upper cog formed at a constant pitch along the longitudinal direction and a lower cog having an lower cog provided on the inner peripheral side of the core wire embedded portion at a constant pitch along the longitudinal direction of the belt. And a double cogged V-belt having a forming part.

[0002]

2. Description of the Related Art As a transmission V-belt for a two-wheeled vehicle transmission, a cogged V-belt having a lower cog formed at a constant pitch along the longitudinal direction on the inner peripheral side of the belt, and on the outer peripheral side and the inner peripheral side of the belt. A double cogged V-belt having upper and lower cogs formed at a constant pitch along the longitudinal direction is used.

In US Pat. No. 4,410,314, the ratio of the lower cog pitch to the upper cog pitch is about 1.4.
0, the ratio of the height of the lower cog to the height of the upper cog is about 1.7.
7. A double cogged V-belt having a ratio of the belt thickness to the belt flexible thickness (the distance between the valley bottoms between adjacent upper cogs and the valley bottoms between adjacent lower cogs) is about 3.98. It is disclosed.

In US Pat. No. 4,494,947, the ratio of the width of the upper part of the belt to the thickness of the belt is about 2.0, the ratio of the lower cog pitch to the upper cog pitch is about 1.40,
The ratio of the height of the lower cog to the height of the upper cog is about 1.77,
A double cogged V-belt is disclosed having a ratio of belt thickness to flexible belt thickness of about 3.98.

In US Pat. No. 4,559,029, the ratio of the width of the upper part of the belt to the thickness of the belt is about 2 to 4, the ratio of the lower cog pitch to the upper cog pitch is about 1.25,
The ratio of the height of the lower cog to the height of the upper cog is about 1.92,
The ratio of the belt thickness to the belt flexible thickness is about 3.68,
Belt thickness is about 0.795 cm (about 0.313 inch)
And the belt flexible thickness is about 0.216 cm (about 0.08
A double cogged V-belt that is 5 inches) is disclosed.

[0006]

SUMMARY OF THE INVENTION It is an object of the present application to provide a double cogged V-belt having excellent flex fatigue resistance.

[0007]

DISCLOSURE OF THE INVENTION The inventor has found out that the highest compression strain occurs between the lower cogs adjacent to each other and the highest tensile strain occurs between the upper cogs adjacent to each other. The present invention is based on this.

A first solving means of the present invention is an endless core wire embedded portion having core wires embedded so as to form a spiral having a predetermined pitch in the belt width direction, and an inner peripheral side of the core wire embedded portion. And a lower cog forming portion having a lower cog formed integrally with the belt longitudinal direction at a constant pitch, and integrally formed on the outer peripheral side of the core wire embedded portion at a constant pitch along the belt longitudinal direction. Assuming a double cogged V-belt having an upper cog forming portion having an upper cog formed therein, the distance from the bottom of the groove extending in the belt width direction between the mutually adjacent lower cogs to the core wire is 2.0 to 3 It is characterized in that it is 0.0 mm.

When the double cogged V-belt is wound around the pulley, a compressive strain is generated in the lower cog forming part around the core wire embedding part. The compressive strain is thinnest to the core wire and easily deforms. Therefore, it becomes the largest at the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other.
According to the above configuration, the distance from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other to the core wire is 2.0 to.
Since the thickness is 3.0 mm, the compressive strain applied there is not excessive, and therefore the bending fatigue resistance is excellent. Here, if the distance is smaller than 2.0 mm, shear strain between the thin groove bottom portion and the highly elastic core wire increases, and the groove bottom portion is cracked or separated from the core wire. There is a risk. If the distance is larger than 3.0 mm, the effect of reducing the compression strain cannot be sufficiently obtained.

A second solving means of the present invention is an endless core wire embedded portion having core wires embedded so as to form a spiral having a predetermined pitch in the belt width direction, and an inner peripheral side of the core wire embedded portion. And a lower cog forming portion having a lower cog formed integrally with the belt longitudinal direction at a constant pitch, and integrally formed on the outer peripheral side of the core wire embedded portion at a constant pitch along the belt longitudinal direction. Assuming a double cogged V-belt having an upper cog forming portion having an upper cog formed therein, and the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is 1.2 mm. It is characterized in that it is not less than 2.0 mm.

When the double cogged V-belt is wound around the pulley, a tensile strain is generated in the upper cog forming portion around the portion where the core wire is embedded. The tensile strain has the smallest wall thickness up to the core wire and is easily deformed. Therefore, it becomes the largest at the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other.
According to the above configuration, the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is 1.2 to.
Since it is set to 2.0 mm, the tensile strain applied there is not too large, and therefore the bending fatigue resistance is excellent. Here, if the distance is smaller than 1.2 mm, the shear strain between the thin groove bottom portion and the highly elastic core wire increases, and the groove bottom portion is cracked or separated from the core wire. There is a risk. If the distance is larger than 2.0 mm, the effect of lowering the tensile strain cannot be sufficiently obtained.

Of course, a combination of the features of the first and second solutions, that is, the distance from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other to the core wire is 2.0 to. It goes without saying that the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to 3.0 mm may be 1.2 mm or more and 2.0 mm or less. Nor.

The dimension setting of the first and second solutions is 2
It is especially effective for double-cogged V-belts for transmission systems of wheeled vehicles.

[0014]

As described above, according to the first solution, the distance from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other to the core wire is 2.0 to 3.0 mm. Therefore, the compressive strain applied thereto is not excessive and the bending fatigue resistance can be improved.

According to the second solution, the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is 1.2 to 2.0 mm. The strain does not become excessive and the bending fatigue resistance can be improved.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings.

1 and 2 show a double cogged V-belt B according to an embodiment of the present invention. The double cogged V-belt B is used for shifting a two-wheeled vehicle.

This double-cogged V-belt B has an endless core wire embedded portion 10, a lower cog forming portion 20 integrally provided on the inner peripheral side of the core wire embedded portion 10, and an outer peripheral side of the core wire embedded portion 10. The upper cog forming portion 30 provided integrally with the upper cog forming portion 30 has a total belt thickness of 12 to 15 mm and a belt width of 1, for example.
It is 1 to 15 mm.

The core wire embedding portion 10 comprises a core wire embedding part body 11 made of a rubber composition, and a core wire 12 embedded in the core wire embedding part body 11 so as to form a spiral having a predetermined pitch in the belt width direction. The rubber composition forming the core wire embedded portion main body 11 is
Chloroprene rubber (CR), ethylene / propylene / diene / terpolymer rubber (EPDM), alkylated chlorosulfonated polyethylene rubber (ACSM), hydrogenated NBR (H-NBR) and the like. The core wire 12 is a twisted yarn of polyester (PET) fiber, aramid fiber, rayon fiber, PBO fiber, etc. and resorcin / formalin /
A predetermined outer diameter d (for example, d = 0.8 to 1.5 mm) that has been subjected to an adhesive treatment in which it is immersed in a latex aqueous solution and then dried.
It consists of things.

The lower cog forming portion 20 comprises a lower cog forming portion main body 22 formed of a rubber composition in which short fibers 21 are oriented in the belt width direction, and a canvas 23 covering the surface thereof. Is 5.0 to 8.0 mm. The rubber component constituting the lower cog forming portion main body 22 is chloroprene rubber (CR), ethylene / propylene / diene / terpolymer rubber (EPDM), alkylated chlorosulfonated polyethylene rubber (ACSM), hydrogenated NBR (H-NB).
R) and the like. The short fibers 21 are, for example, high-strength polyvinyl alcohol (PVA) fibers, para-aramid fibers, aromatic polyester fibers, heterocycle-containing aromatic fibers, and the like. The canvas 23 is made of a woven fabric having ductility made of nylon fiber, cotton, a mixed fiber thereof, a mixed fiber of cotton and polyester fiber, an aramid fiber, etc., which is subjected to an adhesive treatment of being dipped in rubber paste and then dried. Become. The lower cog forming portion 20 has lower cogs 24 arranged at a constant pitch P ₁ (for example, P ₁ = 6 mm) along the longitudinal direction of the belt, and the lower cogs 24 are adjacent to each other in the belt width direction. Groove 2
5 are configured. The outer shape of the vertical cross section of the lower cog 24 is formed in a substantially sinusoidal waveform with a predetermined height h ₁ (for example, h ₁ = 6.5 mm), and the bottom of the groove 25 has a radius R ₁ outwardly concave.
A radius R ₃ (for example, R ₃ = 2.5 m) that is formed in an arc shape of (for example, R ₁ = 2.0 mm) and has a convex top outwardly.
m) is formed in an arc shape. The distance t ₁ from the bottom of the groove 25 extending in the belt width direction between the lower cog 24 adjacent to each other until the core wire 12 is a 2.0 to 3.0 mm.

The upper cog forming portion 30 is formed of a rubber composition in which short fibers 31 are mixed and dispersed so as to be oriented in the belt width direction, and the thickness thereof is 1.5 to 3.0 mm.
The rubber component constituting the upper cog forming portion 30 is chloroprene rubber (CR), ethylene propylene diene terpolymer rubber (EPDM), alkylated chlorosulfonated polyethylene rubber (ACSM), hydrogenated NBR (H-
NBR) and the like. The short fiber 31 is, for example, a high-strength polyvinyl alcohol (PVA) fiber, a para-aramid fiber, an aromatic polyester fiber, a heterocycle-containing aromatic fiber, or the like. The upper cog forming portion 30 has upper cogs 34 arranged at a constant pitch P ₂ (for example, P ₂ = 6 mm) along the longitudinal direction of the belt, and the upper cogs 34 are adjacent to each other in the belt width direction. An extending groove 35 is formed. Upper cog 34
Has a predetermined height h ₂ (for example, h ₂ = 2.2 m
m) is formed in a substantially trapezoidal shape, and a rising corner portion extending from the groove 35 to the hypotenuse is formed in an arc shape having a radius R ₂ (for example, R ₂ = 1.2 mm) outwardly concave, The corner portion extending from the hypotenuse to the upper bottom is formed in an arc shape having a radius R ₄ (for example, R ₄ = 1.0 mm) that is convex outward.
The distance t ₂ from the bottom of the groove 35 extending in the belt width direction to the core wire 12 between the upper cogs 34 adjacent to each other is 1.2.
It is set to ~ 2.0 mm.

The double-cogged V-belt B having the above-mentioned structure
For example, when it is wound around a pulley,
And a compressive strain is generated in the lower cog forming portion 20.
Is that the thickness up to the core wire 12 is the smallest and it is easy to deform
To extend in the belt width direction between the lower cogs 24 adjacent to each other.
Largest at the bottom of the groove 25, but adjacent to each other
The bottom of the groove 25 extending in the belt width direction between the lower cogs 24
Distance t from the core wire 12 ₁As 2.0-3.0 mm
Therefore, the compression strain applied there is not excessive.

A tensile strain is generated in the upper cog forming portion 30 around the core wire embedded portion 10, and the tensile strain is the core wire 1
Since the wall thickness up to 2 is the smallest and is easily deformed, the groove 35 extending in the belt width direction between the upper cogs 34 adjacent to each other is formed.
Although it is the largest at the bottom of the core, the cord 12 extends from the bottom of the groove 35 extending in the belt width direction between the upper cogs 34 adjacent to each other.
Since the distance t ₂ to is 1.2 to 2.0 mm,
The tensile strain applied there is not excessive.

As described above, neither the tensile strain on the outer side of the belt nor the compressive strain on the inner side of the belt is excessive, so that the bending fatigue resistance is extremely excellent.

[0025]

EXAMPLES (Experimental Method) <Experiment 1> In the same double cogged V-belt as in the above embodiment, the distance t ₂ from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is set. The distance t ₁ from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other to the core wire is 0.5 mm.
5mm, 1.0mm, 1.5mm, 2.0mm, 2.5
mm, 3.0 mm, and 3.5 mm were prepared.

Then, as shown in FIG. 3, each double-cogged V-belt B is wound between a driving pulley 41 having a diameter of 126 mm and a driven pulley 42 having a diameter of 104 mm and a load of 71.5 N · m, and the belt tension is increased. 490 N is applied to the driven pulley 42 in a direction away from the drive pulley 41 so that the drive pulley 41 is moved to 755
The double cogged V-belt B was run at 0 rpm until it broke.

<Experiment 2> In the double cogged V-belt similar to the above embodiment, the distance t ₁ from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other to the core wire is 2.
5 mm, the distance t ₂ from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is 0.5 mm,
Those having 1.0 mm, 1.2 mm, 1.5 mm, 2.0 mm and 2.5 mm were prepared.

Then, as in Experiment 1, each double cogged V-belt was run until it broke.

(Test Results) FIG. 4 shows the relationship between the belt bending durability and the distance t ₁ from the bottom of the groove extending in the belt width direction to the core between adjacent lower cogs. FIG. 5 shows the relationship between the belt bending durability and the distance t ₂ from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire. The belt bending durability was shown as a relative value with the bending running life of t ₁ = 2.5 mm and t ₂ = 1.5 mm taken as 100.

According to FIG. 4, when the distance t ₁ from the bottom of the groove extending in the belt width direction to the core wire between the lower cogs adjacent to each other is in the range of 2.0 to 3.0 mm, the longest bending running life is reached. On the other hand, it has a bending running life of 90% or more, that is,
It can be seen that the bending fatigue resistance is excellent.

According to FIG. 5, when the distance t ₂ from the bottom of the groove extending in the belt width direction to the core wire between the upper cogs adjacent to each other is 1.2 to 2.0 mm, the longest bending running life is reached. On the other hand, it has a bending running life of 90% or more, that is,
It can be seen that the bending fatigue resistance is excellent.

[Brief description of drawings]

FIG. 1 is a perspective view of a double cogged V-belt according to an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a double cogged V-belt according to an embodiment of the present invention.

FIG. 3 is a layout diagram of a belt durability running tester.

FIG. 4 is a graph showing the relationship between the belt durability and the distance from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other.

FIG. 5 is a graph showing the relationship between the belt durability and the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other.

[Explanation of symbols]

B Double Cogged V Belt 10 cores buried part 11 Core wire buried part body 12 cores 20 Lower cog forming part 21,31 Short fiber 22 Main body of lower cog forming part 23 canvas 24 Lower Cog 25,35 groove 30 Upper cog forming part 34 Upper Cog 41 Drive pulley 42 Driven pulley

Claims (4)

[Claims] 1. An endless core wire embedded portion having core wires embedded so as to form a spiral having a predetermined pitch in a belt width direction, and a belt longitudinal direction integrally provided on an inner peripheral side of the core wire embedded portion. A lower cog forming portion having a lower cog formed at a constant pitch along the upper cog and an upper cog having an upper cog integrally provided on the outer peripheral side of the core wire embedded portion and formed at a constant pitch along the belt longitudinal direction. Double cogged V with forming part
A double cogged V-belt, wherein the distance from the bottom of the groove extending in the belt width direction between the lower cogs adjacent to each other to the core wire is 2.0 to 3.0 mm. 2. The double cogged V-belt according to claim 1, wherein the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is 1.2 to 2.0 mm. A double cogged V-belt featuring. 3. An endless core wire embedded portion having core wires embedded so as to form a spiral with a predetermined pitch in the belt width direction, and a belt longitudinal direction integrally provided on the inner peripheral side of the core wire embedded portion. A lower cog forming portion having a lower cog formed at a constant pitch along the upper cog and an upper cog having an upper cog integrally provided on the outer peripheral side of the core wire embedded portion and formed at a constant pitch along the belt longitudinal direction. Double cogged V with forming part
A double cogged V-belt, characterized in that the distance from the bottom of the groove extending in the belt width direction between the upper cogs adjacent to each other to the core wire is 1.2 to 2.0 mm. 4. The double cogged V-belt according to any one of claims 1 to 3, which is for a transmission device of a two-wheeled vehicle.