JPH04342679A - Rubber crawler for travel on snow and ice - Google Patents

Abstract

PURPOSE:To provide a rubber crawler mainly for use with a snowplow, a snowmobile or the like for a travel on snow and ice, and further provide a rubber crawler particularly suitable for travel on ice and a frozen road, while using a rubber material having a high friction coefficient. CONSTITUTION:A rubber crawler in the title is used for the travel section of a snowplow or the like in the form of extension between a sprocket and an idler. A rubber lug is formed on the external surface of the crawler, and rubber foam or rubber containing a solid material kneaded into rubber is used at least as the surface layer of the lug. In the case of the application of the rubber foam, the hardness of a rubber foam layer is preferably lower than the hardness of a rubber layer forming the body of the crawler for use as a rubber crawler for travel on ice.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber track for use on snow and ice, which is mainly used for snowplows, snowmobiles, and the like. .

0002

2. Description of the Related Art Conventionally, rubber tracks have been mainly used as running parts of agricultural machinery, but in recent years, they have been used as running parts of construction machines, civil engineering machines, and even snowplows. This is because they have better low noise and vibration properties compared to conventionally used iron shoe tracks. Among these, the present invention relates to rubber tracks used as running parts of snow vehicles. Rubber tracks used as running parts of snow and ice vehicles include those in which a plate with protrusions is embedded in the rubber track and the protrusions protrude from the lug surface (Japanese Patent Application Laid-open No. 83233/1983); A device in which spike-shaped protrusions are integrally formed on a large number of core metals embedded in a rubber crawler track (Japanese Patent Application Laid-Open No. 59-2135
No. 77) has been proposed. However, once these are worn out, they are no longer effective, and in some cases they may even damage the paved road, especially if the vehicle is driven on a road that alternates between snow or ice and paved road.

0003

[Problems to be Solved by the Invention] Unlike the above configuration, the present invention uses a material with an excellent coefficient of friction for the rubber crawler track itself, and is particularly made of rubber suitable for running on ice and frozen roads. To provide tracks.

0004

[Means for Solving the Problems] The present invention solves the problems by adopting the following configuration. That is, the first aspect of the present invention is to use foamed rubber on the surface of at least the lugs formed on the ground contact side of the rubber crawler track, and the second aspect of the present invention is to use foamed rubber on the surface of at least the lugs formed on the ground contact side of the rubber crawler track. In both cases, rubber with lumps kneaded into it is used, and in both cases, the surfaces of the lug portions are made of rubber that has a high coefficient of friction against snow and ice surfaces.

In the first invention, it is generally desirable that the hardness of the rubber layer forming the main body of the rubber footwear is higher than the hardness of the foamed rubber layer. Such foamed rubber can be obtained by using a blowing agent, by mechanical stirring, by foaming gas during a chemical reaction, by incorporating microballoons, or by mixing a low-boiling volatile solvent. Although there are various types of foaming agents, it is generally preferable to use a foaming agent that is blended into rubber and decomposed by heating to generate gas to form foamed rubber.

Among these blowing agents, there are organic blowing agents that are stable compounds at room temperature and generate gas when heated;
Examples include azonitrile compounds, benzenesulfohydrazine compounds, diazoamide compounds, and the like. This foamed rubber is used at least on the surface of the lug portion formed on the ground side of the rubber track, and in some cases, it is also possible to use this rubber on the entire ground side of the rubber track.

[0007] In the second aspect of the invention, examples include those in which ceramics, ultra-high molecular weight polyethylene, etc. are blended into rubber as the lumpy objects. Particularly preferably, these lumps have sufficiently reacted with the rubber, and can be obtained, for example, by kneading the rubber and ultra-high molecular weight polyethylene in the presence of a radical initiator and a crosslinking agent at a temperature above the softening point of the polyethylene. A rubber composition having a heterogeneous structure in which a polymer alloy compound of 100% is blended into rubber is used in the surface layer of at least the lugs of the rubber crawler track.

The molecular weight of the ultra-high molecular weight polyethylene herein is 500,000 or more, preferably about 800,000 to 5,000,000. If the molecular weight of such ultra-high molecular weight polyethylene is too small, good dispersion with rubber cannot be obtained, while if it is too large, kneading with rubber becomes difficult. Examples of radical initiators include thiazole-based initiators such as dibenzothiazyl sulfide, thiuram-based initiators such as tetramethylthiuram disulfide, and guanidine-based initiators such as diphenylguanidine. Things can be mentioned.

[0009]

[Effect] The frictional force between rubber and an object includes hysteresis frictional force, viscous frictional force, digging frictional force, water removal effect, etc. Other than hysteresis frictional force, the effects vary greatly depending on the uneven structure of the surface. come. In the first aspect of the present invention,
At least on the surface of the lugs of the rubber footwear, there are many small holes caused by foaming, and these are effective in addition to the hysteresis friction force described above. On the other hand, in the second aspect of the present invention, contrary to the first aspect, a large number of protrusions of small lumps are made to protrude from the rubber surface. This is an attempt to obtain frictional force.

0010

[Examples] The present invention will be explained in more detail below using examples. (Example 1, Comparative Example 1) As a first example of the present invention, an example is shown in which foamed rubber mixed with a foaming agent is used for a rubber lug. A rubber track was obtained by using 2.5 parts of dinitropentamethylenetetramine as a foaming agent and using this rubber for the surface layer of the rubber lug of the rubber track according to the formulation (parts by weight) shown in Table 1 as the foamed rubber composition. . Regarding the foaming rate V, the density of foamed rubber is ρ0, and the density of non-foamed rubber is ρ1.
, it is expressed by Equation 1.

[0011]

[Formula 1]

As a comparative example, a rubber track was constructed without adding a foaming agent, but instead with 30 parts of a low-temperature softener. For the braking and skidding tests on ice, a filling test was conducted with the results of the rubber footwear of the comparative example set as 100. The test results are also shown in Table 1, and the results were good.

(Examples 2 to 5, Comparative Example 2) Next, as a second example of the present invention, a rubber track was manufactured using a polymer alloy compound. Styrene-butadiene rubber (SBR) and styrene-butadiene (SB) block copolymer rubber were used as the polymer alloy composition under the formulation (parts by weight) shown in Table 2 below. Here, a mixture of dibenzothiazyl sulfide (DM), diphenylguanidine (DPG) and zinc white was used as the radical initiator.

[0014]

[Table 2]

[0015] These blends and ultra-high molecular weight polyethylene with an average molecular weight of 3 million were mixed in a kneader at about 160 degrees Celsius.
By kneading for 5 minutes, two types of polymer alloy formulations (A) and (B) were obtained. Next, the obtained polymer alloy blends (A) and (B) were added to rubber at the blending ratio shown in Table 3 and the blending recipe (parts by weight) shown in the same table,
A rubber composition with a heterogeneous structure was obtained, and this was used for the lug portion of a rubber crawler track to manufacture a crawler track.

[0016]

[Table 3]

The evaluation items are also shown in Table 3. Among the evaluation items, abrasion resistance is the result of a Lambourn abrasion test under constant load, and a larger value indicates better abrasion resistance. The ice test was a feeling test as in the previous example, and the results were expressed as an index, with the rubber track using the rubber of Comparative Example 1 as 100. According to the present invention, the braking performance is improved and the occurrence of sideslip is greatly reduced.

[0018]

[Effect] As can be seen from the above results, in the rubber footwear of the present invention, many small irregularities are formed at least on the surface of the lugs that come into contact with snow and ice, and the frictional resistance is significantly increased. It has excellent braking performance and grip performance, and the occurrence of sideslips is greatly reduced.

[Table 1]

Claims (4)

[Claims] 1. A rubber footwear for snow and ice used for the traveling part of a snowplow or the like, which is wound between a sprocket and an idler, wherein a rubber lug is formed on the outer peripheral surface of the footwear, and at least the surface of the rubber lug is Rubber footwear for snow and ice, characterized by using foamed rubber as a layer. 2. The rubber footwear for snow and ice according to claim 1, wherein the hardness of the foamed rubber layer is lower than the hardness of the rubber layer forming the main body of the rubber footwear. 3. A rubber footwear for snow and ice used for a running part of a snowplow or the like, which is wound between a sprocket and an idler, wherein a rubber lug is formed on the outer peripheral surface of the footwear, and at least the surface of the rubber lug is Rubber footwear for use on snow and ice, characterized in that the layer is made of rubber in which lumps are kneaded into the rubber. 4. The rubber footwear for snow and ice according to claim 3, wherein the lumpy material is ceramic or ultra-high molecular weight polyethylene.