JP2000053038A - Truck belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the tractive protrusion on a truck belt to intrude into the snow, strengthen buffer force to the external force, and lessen slippage on consolidated snow when a snow vehicle or the like travels on consolidated snow. SOLUTION: The hardness of a rubber material from the tip 22a of a tractive protrusion 22 to a base part 22b is layer-wise changed from a hard rubber to a soft rubber. For example, JIS hardness Hs is made in two layers of 80 deg. at the tip 22a and 60 deg. at the base part 22b or in three layers of 80 deg. at the tip 22a, 70 deg. at the intermediate part 22c and 60 deg. at the base part. Thus the tip 22a of high rigidity can easily intrude into the snow, not easily slipping and, because the soft base part damps the external force, deterioration of durability due to breakage can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing the occurrence of slip on a consolidated snow surface without lowering the traction force of a traction projection of a track belt when a snowmobile or the like travels on the consolidated snow surface. It is intended to be less.

[0002]

2. Description of the Related Art A track belt mounted on a snowmobile or the like has a structure in which three endless belt bodies are fixed in a circumferential direction as described in, for example, Japanese Patent Application Laid-Open No. 6-24366. Are connected in the width direction by lateral rigid members arranged at intervals of. In each belt body, a core material is disposed on the inner peripheral side of the lateral rigid material, and an inner layer reinforcing cloth and an outer layer reinforcing cloth are disposed on the inner peripheral side of the core material and the outer peripheral side of the lateral rigid material, respectively. The inner peripheral side of the inner-layer reinforcing cloth and the outer peripheral side of the outer-layer reinforcing cloth are covered with an inner-layer cover rubber and an outer-layer cover rubber, respectively, and have a laminated structure in which they are vulcanized and bonded.

[0003] On the surface (contact road surface) of the outer layer cover rubber of the belt body, there is provided a traction projection integrally formed in a predetermined shape pattern at the same position as the circumferential and widthwise arrangement of the lateral rigid members. is there.

[0004] The traction protrusion of the track belt is a portion that exerts a desired traction force by penetrating into a snow surface against which the track belt presses when traveling on snow.
In order to maintain the rigidity required to fulfill the function, the conventional traction projection is formed using a rubber material or a rubber-like elastic material having a JIS hardness (Hs) of about 60 degrees.

[0005] However, the traction projections made of rubber material having the hardness as described above can provide necessary and sufficient traction force when a snowmobile travels on a relatively soft snow-covered surface. When the surface is solidified in a hard pack shape, not only does the degree of penetration of the traction projection into the snow surface decrease and the traction force decreases, but also the displacement of the tip of the traction projection increases. However, there is a problem that the vehicle easily slips.

[0006]

SUMMARY OF THE INVENTION As described above, the present invention relates to a method in which an outer layer cover rubber of an endless belt body whose inner and outer peripheral surfaces are covered with a cover rubber is provided with a predetermined circumferential interval. In a track belt in which traction projections parallel to the width direction are formed integrally with each other, even when the snow surface pressed against the running path is solidified, the traction projections easily penetrate into the snow surface and slip. It is an object of the present invention to have low rigidity.

[0007]

Means for Solving the Problems In order to solve the above problems, a means adopted by the present invention is to make the rubber hardness at the tip of the traction projection of the track belt harder than the rubber hardness of the base. Claim 1).

[0008] Generally, the pulling projection of this type of track belt is inevitably brought about because it is formed in a vertically long triangular or trapezoidal cross section. The rigidity of the part is low.

According to the first aspect of the present invention, the rigidity of the tip of the traction projection is increased even if the shape and size of the traction projection are the same as those of the prior art, so that the vehicle travels on a road surface on which snow is solidified. In addition to this, not only is it easier to penetrate the snow surface, but also the shape and dimensions of the tip are thinner than before, and the rigid cross section has a higher degree of penetration into the consolidated snow surface Can also be formed.

[0010] In addition, with the above configuration, the rigidity at the tip of the traction projection is increased, so that even when the tip is pressed against the consolidated snow surface, the displacement of the tip is small, and the running stability is reduced due to slip. Can be avoided.

Further, since the base of the traction projection has lower rigidity and flexibility than the tip, the buffering force against external force is strong, and the base may be broken even when subjected to an impact from a solidified snow surface. In this case, only the tip portion is damaged at most, and the traction protrusion has excellent durability.

In the present invention, it is preferable that the rubber hardness at the distal end of the traction projection is hierarchically higher than the rubber hardness of the base (claim 2). Contrary to this, if there is an excessive difference in the rubber hardness from the base to the tip of the traction projection, the rigidity in the height direction of the traction projection changes rapidly,
Breakage due to external force is likely to occur.

As described above, a specific example of the case where the rubber hardness from the base to the tip of the traction projection is hardened is as follows.
For example, the base has a two-layer structure of 60 degrees Hs and the tip has 80 degrees Hs (claim 3), or the base has 60 degrees Hs.
It is preferable that the intermediate portion has a three-layer structure of 70 degrees Hs and the tip portion has 80 degrees Hs (claim 4). If necessary, four or more layers in which the rubber hardness is gently changed by further subdivided numerical values are used. It can also be structured.

In any of the above cases, the lower limit of the rubber hardness at the base of the traction projection is set to 60 degrees Hs in order to ensure the minimum rigidity required for the base and the upper limit of the rubber hardness at the tip. Is set to Hs80 degrees because Hs80
If the rubber hardness exceeds the required degree, it becomes difficult to secure the necessary minimum flexibility at the tip.

[0015]

Embodiments of the present invention will be described with reference to the drawings. One example of a track belt according to the present invention is shown in FIG. 1 as a partially cutaway perspective view. The track belt 10 shown in FIG. 1 is mounted on a snowmobile and has three endless belt bodies 10a, 10b, 1
0c are connected via a plurality of transverse rigid members 12 arranged in the width direction at predetermined intervals in the circumferential direction.

Each belt body 10a, 10b, 10c
A core member 14 is provided along the circumferential direction on the inner peripheral side of the lateral rigid member 12, and the core member 14 covers the inner peripheral side of the core member 14 and the outer peripheral side of the core member 14 and the lateral rigid member 12. Inner layer reinforcing cloth 15 and outer layer reinforcing cloth 16 arranged in the direction, and inner layer cover rubber 17 and outer layer cover for covering the inner peripheral side of inner layer reinforcing cloth 15 and the outer peripheral side of outer layer reinforcing cloth 16 to protect the above members. Rubber 18
And vulcanized to form an integrated structure.

The core member 14 is composed of belt bodies 10a, 10b,
A member that retains the strength of 10c and is made of a woven fabric, cord, or the like of a tensile strength synthetic fiber or a metal fiber;
Reference numeral 2 denotes a rod-shaped body made of a fiber-reinforced synthetic resin or the like for securing the lateral rigidity of the belt bodies 10a, 10b, and 10c. The inner and outer layer reinforcing cloths 15, 16 are woven cloths such as plain weaves made of synthetic fibers. The core member 14 is protected from damage, the lateral rigid member 12 is prevented from jumping out, and the belt body 10 is
a, 10b, and 10c are members for securing rigidity. Inside
The outer cover rubbers 17 and 18 are protection members that cover the respective components disposed on the inner peripheral side thereof, and are members that transmit a driving force during traveling of a snowmobile and exhibit traction force. The drive protrusion 21 is provided on the inner peripheral surface of the belt body 10b (the surface of the inner cover rubber 17), and the respective belt bodies 10a, 10b, 10c
On the outer peripheral surface (the surface of the outer layer cover rubber 18)
2 are formed at circumferential positions corresponding to the lateral rigid members 12 at intervals.

The track belt 10 is endlessly wrapped around a drive wheel and a driven wheel mounted on a snowmobile body via a suspension device (not shown), and a drive projection 21 is formed between the drive wheel and the driven wheel. The driving force is transmitted to the track belt 10 by meshing with each other, and the traction protrusions 22 press against the running snow surface and exert traction force by penetrating into the snow surface.

A sliding metal fitting 2 with a guide is provided in a circumferential gap provided between the belt bodies 10a, 10b and 10c, which are connected to each other via a lateral rigid member 12, in the width direction.
4 and the sliding metal fittings 26 are alternately mounted on the lateral rigid member 12 with a rubber cushion therebetween.
A slide rail (not shown) of the suspension device is mounted on the sliding metal fitting 26, and in this state, the sliding metal fittings 24 and 26 slide while supporting the weight of the snowmobile.

The track belt 1 configured as described above
FIG. 2 shows a configuration in which the rubber hardness at the tip of the traction projection 22 formed on the surface of the outer layer cover rubber 18 is made hierarchically higher than the rubber hardness at the base at 0.

In the embodiment shown in FIG. 2A, the traction projection 22 is composed of a rubber layer divided into two layers, a tip 22a and a base 22b, and the rubber hardness of each layer is JIS hardness (Hs) and the tip 22a. At 80 degrees and the base 22b at 60 degrees.

As described above, the outer cover rubber 1
8 is provided at a position corresponding to the circumferential position in which the lateral rigid member 12 is embedded, and an inner layer reinforcing cloth 15 is provided on the inner peripheral side of the lateral rigid member 12 via the core member 14. An outer layer reinforcing cloth 16 is disposed on the outer peripheral side of the lateral rigid member 12, and the inner peripheral side of the inner layer reinforcing cloth 15 and the outer peripheral side of the outer layer reinforcing cloth 16 are formed by an inner layer cover rubber 17 and an outer layer cover rubber 18, respectively. Coated. Further, the drive projection 2 of the inner layer cover rubber 17 is provided.
1 is provided at a circumferential position corresponding to the lateral rigid member 12.

In the embodiment of the traction projection 22 shown in FIG. 2B, an intermediate portion 22c is provided between the tip portion 22a and the base portion 22b.
The rubber hardness of each layer is JIS hardness (Hs), the tip 22a is 80 degrees, the middle 22c is 70 degrees, and the base 22b is 60 degrees.

The configuration other than the above is the same as that described with reference to FIG.

[0025]

As described above, according to the present invention, as the rubber material of the traction projections provided integrally with the outer cover rubber of the track belt, the hardness at the tip is higher than the hardness of the base. Even when traveling on a solidified snow surface, it is easy to increase the degree of penetration of the tip of the traction projection into the snow surface, so that a desired traction force can be secured, and The base of the traction projection made of soft rubber material has a sufficient cushioning force against external force such as impact received from the traveling road surface, so that the base itself does not break and it can be used for a long time In addition to being excellent in durability, the amount of displacement when the tip of the traction projection is pressed against the solidified snow surface is reduced, so that the occurrence of slip is reduced and the running stability is also reliable. The high (claim 1).

Further, in the present invention, when the hardness of the rubber material of the traction projection is made hierarchically hard from the base to the tip, the degree of change in the rigidity in the height direction of the traction projection becomes gentle. In addition, the buffering force against external force increases, and the effect of preventing breakage due to the impact of the traction projections is further increased (claim 2).

Further, in the present invention, the hardness of the rubber material of the pulling projection is Hs 60 degrees at the base and Hs 8 at the tip.
A two-layer structure of 0 degrees or a base of Hs 60 degrees,
When the intermediate portion has a three-layer structure of Hs 70 degrees and the tip portion has a Hs 80 degrees, the effect obtained by the present invention can be more easily achieved (claims 3 and 4).

[Brief description of the drawings]

FIG. 1 is a cutaway perspective view showing an example of a track belt of the present invention.

FIG. 2 is a longitudinal sectional view showing an embodiment of a traction projection of an outer cover rubber.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Track belt 10a, 10b, 10c Belt main body 18 Outer layer cover rubber 22 Traction protrusion 22a, 22b, 22c
Middle part

Claims (4)

[Claims] 1. An outer end cover rubber of an endless belt body whose inner and outer peripheral surfaces are respectively covered with a cover rubber and integrally provided with traction projections parallel to the width direction at predetermined circumferential intervals. A track belt, wherein the rubber hardness at the tip of the traction projection is higher than the rubber hardness at the base. 2. The track belt according to claim 1, wherein a rubber hardness of a tip portion of the traction projection is hierarchically harder than a rubber hardness of a base portion. 3. The rubber hardness of the base of the traction projection is Hs6.
The track belt according to claim 2, wherein the degree is 0 degree and the rubber hardness at the tip is 80 degrees Hs. 4. A rubber base at the base of said traction projection has a hardness of Hs6.
The track belt according to claim 2, wherein the degree of hardness is 0 degree, the rubber hardness of the intermediate portion is 70 degrees Hs, and the rubber hardness of the tip portion is 80 degrees Hs.