JP2009274596A - Elastic body crawler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic crawler which prevents the occurrence of deformation, tilting or the like of a lug and can prevent complication of manufacturing work. <P>SOLUTION: The elastic crawler has a crawler body 2 formed of an elastic body and a plurality of core bars 4 embedded circumferentially in the crawler body with an interval. A plurality of the lugs 3a, 3b protruded outward and extended long in a width direction are integrated with the core bars in circumferentially overlapping positions at the outer face 13 of the crawler body 2. The roots where the lugs are continuous with the crawler body and the circumferential vicinities of the roots are made to be high hardness parts 20a, 20b which have higher hardness than that at the other part and are formed of the elastic body extended with a width W1 in the width direction. The difference in the hardness between the high hardness part and the other part is not lower than 10° and not higher than 25°. The ratio of a distance L from the protruded end of the lug to the high hardness part to the height H of the lug is not less than 0.6 and not more than 0.95. The ratio of the width W1 of the high hardness part to the circumferential thickness W of a part with a height half the height H of the lug is 2.5 to 3.6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an elastic crawler mounted on a crawler type traveling vehicle.

A crawler type traveling vehicle often travels on a ground surface that is not leveled, and at that time, an elastic body crawler formed of rubber, which is an elastic body, is deformed into a lug, falls, etc. due to the traveling uneven surface Will occur. This deformation, collapse, etc. reduce the force with which the lag catches the ground surface, that is, the traction force. Moreover, if the lug is repeatedly deformed, collapsed, etc., it may cause uneven wear or cracks in the lug or crawler body.
In order to prevent such deformation, collapse, and the like of the lug in the elastic crawler, a technique for embedding a rubber core having a hardness higher than that of other parts in the lug is disclosed (Patent Document 1).
Japanese Patent Laid-Open No. 9-249163

In order to prevent deformation, collapse, etc. of the lug, measures such as widening the lug (widening the width of the grounding side of the lug), devising the shape of the lug, or changing the height of the lug can be considered. . It is also conceivable to solve the problem by adopting a two-layer tread method in which two different tread rubbers are molded and vulcanized.
However, measures such as widening the lug or changing the height of the lug increase the weight of the elastic crawler, which increases the manufacturing cost.
When the two-layer tread method is adopted, two different tread rubbers are necessary, and there is a problem that a storage space for a raw material having a certain size is required, and there is a possibility that the raw material may be mistaken at the time of molding.

On the other hand, the elastic body crawler disclosed in Patent Document 1 can be expected to prevent the occurrence of deformation, collapse, and the like of the lug by the action of the hard rubber embedded in the lug.
However, the elastic crawler disclosed in Patent Document 1 needs to assign a high-hardness rubber to a predetermined position for each of a large number of concave portions forming the lug of the mold when the lug is vulcanized. There is a problem that the manufacturing work becomes complicated.
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an elastic crawler that can prevent the occurrence of deformation and collapse of a lug and avoid the complexity of manufacturing operations.

  An elastic crawler according to the present invention includes a crawler main body formed in an endless belt shape by an elastic body, and a plurality of core bars embedded in the crawler main body at intervals in the circumferential direction of the crawler main body. And a plurality of lugs protruding outward and extending in the width direction of the crawler main body are integrated with the different ones of the core bars in the circumferential direction on the outer peripheral surface of the crawler main body, The base where the lug is continuous with the crawler body and the vicinity in the circumferential direction are high-hardness portions formed of an elastic body having a hardness higher than that of other portions and extending in the width direction with a width W1. The difference in hardness between the portion and the high hardness portion is not less than 10 degrees and not more than 25 degrees, and the ratio of the distance L from the protruding end of the lug to the high hardness portion and the height H of the lug (L / H ) Is 0.6 or more and 0.95 or less And the ratio (W1 / W) between the width W1 of the high hardness portion and the thickness W in the circumferential direction of the lug at a half of the height H of the lug is 2.5 or more and 3.6 or less. .

The high hardness part may be formed of a resin having rubber-like elasticity.
In the above description, “a position where a plurality of lugs overlap with any one of the cores in the circumferential direction” means a position where one lug overlaps one core when the elastic crawler is viewed from the grounding side. It means that there is.

  ADVANTAGE OF THE INVENTION According to this invention, generation | occurrence | production of a deformation | transformation, a fall, etc. of a lug can be prevented, and the elastic body crawler which can avoid the complexity of manufacturing operation can be provided.

1 is a diagram of the elastic crawler 1 viewed from the grounding side, FIG. 2 is a sectional view taken along line AA in FIG. 1, and FIG. 3 is a sectional view taken along line BB in FIG.
In the following description, the inner side of the elastic crawler 1 when mounted on a crawler type traveling vehicle is referred to as an “inner peripheral side”, and the outer side serving as a ground contact surface is referred to as an “outer peripheral side”. Further, the direction in which the elastic crawler 1 circulates when the crawler type traveling vehicle travels is “circumferential direction”, and the direction orthogonal to the circumferential direction at this time and parallel to the rotation axis of the crawler type traveling vehicle such as a wheel. It shall be called “width direction”.

1 to 3, an elastic crawler 1 includes a crawler body 2, lugs 3a, 3a, 3b, 3b, cored bars 4, 4, 4, 4 and a pair of tensile members 5, 5 and the like. Become.
The crawler main body 2 forms a basic part of the elastic crawler 1 formed in an endless belt shape. The crawler body 2 is formed by joining both ends of a thick band-like rubber. On the inner peripheral surface 11 of the crawler main body 2, two wheel traveling zones 12, 12 are provided symmetrically with a gap on both sides in the center in the width direction. The roller running zones 12 and 12 are portions on which the wheels roll when the crawler type traveling vehicle travels, and are formed over the entire circumferential direction of the crawler body 2. In the vicinity of both ends in the width direction of the outer peripheral surface 13 (hereinafter referred to as “outer surface 13”) of the crawler main body 2, concave portions 14 and 14 that are concave on both sides in the width direction extend in the circumferential direction. The recesses 14 and 14 are discontinuously formed over the entire circumferential direction of the crawler body 2 by being blocked by the long lugs 3a.

The crawler body 2 is formed of two types of rubber having different hardness. This will be described in detail later.
The lugs 3a and 3b include a long lug 3a and a short lug 3b, both of which protrude outwardly from the outer surface 13 of the crawler body 2 and extend long in the width direction. The long lugs 3a and the short lugs 3b have the same extent (height H) protruding outward.
The long lug 3a extends substantially in the entire width direction of the crawler body 2. The short lug 3b has a length that is approximately half the width of the crawler body 2 (distance between both ends in the width direction), and is provided between the two concave portions 14 and 14. The long lugs 3a and the short lugs 3b are alternately arranged in the circumferential direction so that the distance between the adjacent long lugs 3a and the short lugs 3b is constant. Moreover, as FIG. 3 shows, the shape of the long lug 3a and the short lug 3b in the cross section cut | disconnected in the circumferential direction in the center of the width direction is the same.

The cored bar 4 is formed of a hard material such as metal. The cored bar 4 is composed of a cored bar body 15 and a pair of protrusions 16, 16 that are substantially rectangular plate-like as a whole.
The core metal body 15 has a portion 17 having a constant length in the center in the longitudinal direction (hereinafter referred to as “core metal center portion 17”) having a large thickness, and one surface 18 is the other surface on both sides in the longitudinal direction. It is inclined with respect to 19, and the thickness is gradually reduced toward both ends in the longitudinal direction. The other surface 19 has a cored bar central portion 17 projecting from both sides in the longitudinal direction, and steps are formed between the cored bar central portion 17 and both sides in the longitudinal direction.

Each of the protrusions 16, 16 protrudes from the vicinity of each end in the longitudinal direction of the core metal central portion 17 on one surface 18. The protrusions 16 and 16 are spaced in the width direction. It can be said that the protrusions 16 and 16 are covered with rubber continuous with the crawler main body 2 and embedded in the crawler main body 2.
The cored bar 4 is embedded in the crawler body 2 such that the protrusions 16 and 16 protrude toward the inner peripheral side and the longitudinal direction of the cored bar body 15 is the width direction of the crawler body 2. One surface 18 of the core metal central portion 17 is exposed to the inner peripheral side together with the protrusions 16 and 16.

The protrusions 16 and 16 are for guiding the wheels so that the elastic crawler 1 does not fall off from the wheels when, for example, a crawler type traveling vehicle travels. Therefore, the cored bar 4 is embedded in the crawler main body 2 so that the projecting portions 16 and 16 are located on the outer sides in the width direction of the roller traveling zones 12 and 12 of the crawler main body 2. Further, both sides of the metal core main body 15 in the longitudinal direction extend outward from the wheel travel zones 12 and 12, and the wheel travel zones 12 and 12 with respect to the load of the traveling vehicle from the wheels. Is reinforced.
As shown in FIGS. 1 and 2, the core bars 4 and 4 are arranged on the inner peripheral side of the lugs 3a and 3b and so as to overlap the lugs 3a and 3b in the circumferential direction. Here, “overlap in the circumferential direction” means that the elastic crawler 1 overlaps when viewed from the grounding side, for example, as shown in FIG.

The tensile bodies 5 and 5 are formed by arranging a plurality of tensile cords such as steel cords in a line in the width direction. Each of the tensile members 5 is located in the immediate vicinity of the other surface 19 of the cored bar 4 and on the outer side in the widthwise direction than any different side step formed at the widthwise end of the cored bar body 15. It is wound over the entire direction.
Now, the crawler body 2 is formed of two types of rubbers having different hardnesses. These two types of rubber are, for example, a low hardness rubber having a durometer hardness of 60 to 70 degrees and a high hardness rubber having a durometer hardness of 70 to 95 degrees. The crawler body 2 is made of low-hardness rubber except for the parts described below.

The high-hardness rubbers 20a and 20b are arranged in a belt shape on the outer peripheral side of the cored bar 4 with a predetermined thickness and a predetermined width W1 (distance between both ends in the circumferential direction of the crawler body 2). Part of it. The width W1 of the high hardness rubbers 20a and 20b is larger than the width of the core metal body 15 (distance between both ends in the circumferential direction of the crawler body 2).
Referring to FIG. 1, high-hardness rubber 20 a located on the outer peripheral side of cored bar 4 that overlaps with long lug 3 a extends to the entire width of crawler body 2. On the other hand, the high-hardness rubber 20b positioned on the outer peripheral side of the core metal 4 that overlaps the short lug 3b has a slightly shorter length in the width direction than the short lug 3b. Referring to FIG. 3, in both the long lug 3 a and the short lug 3 b, the root portion that is continuous with the crawler body 2 is formed of high hardness rubbers 20 a and 20 b. That is, both the long lug 3a and the short lug 3b are formed of a low hardness rubber at a constant distance (L) from the outer peripheral end to the inner peripheral side. The remaining portions of the long lugs 3a and the short lugs 3b, and the constant width W1 between these portions and the cored bar 4 and on both sides in the circumferential direction are formed by the high hardness rubbers 20a and 20b. .

The high-hardness rubber 20a located on the outer peripheral side of the cored bar 4 overlapping the long lug 3a and the high-hardness rubber 20b positioned on the outer peripheral side of the cored bar 4 overlapping the short lug 3b have a length extending in the width direction. Except for the difference, the shape and the dimensions of each part such as the width W1 are the same.
Table 1 shows the difference in hardness between the two types of rubber, the width W1 in the circumferential direction of the high hardness rubbers 20a and 20b, and the thickness thereof in the elastic crawler 1 having the crawler body 2 formed of two types of rubbers having different hardnesses. These are the results of examining the degree of traction, partial wear, and cracks of the elastic crawler 1 by variously changing the above.

In Table 1, the reference (conventional product) is an elastic crawler having the same configuration as the elastic crawler 1 except that the crawler body is formed of one kind of rubber having a durometer hardness of 80 degrees. Further, the elastic crawler 1B in the comparative example 7 does not dispose the high-hardness rubber only on the outer peripheral side of the cored bars 4 and 4, but as shown in FIG. 4, the high-hardness rubber 20B is made of the elastic crawler 1B. Are arranged continuously in the circumferential direction. In FIG. 4, the same reference numerals as those in the elastic crawler 1 are given to portions having the same configuration as the elastic crawler 1.
L in Table 1 is the distance from the outer peripheral side tips (projecting ends) of the lugs 3a and 3b to the high hardness rubbers 20a and 20b, that is, the heights of the lugs 3a and 3b formed of the low hardness rubber. H is the distance from the outer peripheral end of the lugs 3a, 3b to the outer surface 13 of the crawler body 2, that is, the height of the lugs 3a, 3b.

W1 is the width of the high hardness rubbers 20a and 20b (distance between both ends in the circumferential direction of the crawler body 2). W is the thickness (width) in the circumferential direction at a position half the height H of the lugs 3a, 3b.
The height L of the lugs 3a, 3b formed of the low hardness rubber, the height H of the lugs 3a, 3b, the width W1 of the high hardness rubbers 20a, 20b, and the half of the height H of the lugs 3a, 3b. The thickness W is typified by a value at the center in the width direction of the elastic crawler 1, but between the concave portions 14, the thickness W is substantially the same in any portion.

Traction force, uneven wear and cracks were evaluated as follows.
First, the test method will be described.
On a large iron conveyor belt (hereinafter referred to as “track belt”) that circulates by power, two elastic crawlers 1 are mounted on both sides in the width direction, and a tester that can be circulated by the power incorporating the same is mounted. The test machine imitates a crawler type traveling vehicle. A weight is added to the test machine so that the total weight of the test machine is the same as that of the crawler type traveling vehicle on which the elastic crawler 1 is scheduled to be mounted. The test machine is connected by a rope having one end fixed to a support column, and a load cell capable of measuring a tensile force applied to the rope is provided in the middle of the rope.

The traction force is measured by attaching the elastic crawler of Comparative Example 1 in Table 1 to a test machine and circulating it at a predetermined crawler moving speed (5 km / hr in this test), and the tensile force measured by the load cell is constant (this test Then, the moving speed of the track belt is adjusted to 500 kg). At this time, the traction force of the elastic crawler of Comparative Example 1 is set to 100.
Under the same conditions (the same crawler moving speed and track belt moving speed as described above), the tensile force in the elastic crawlers of the examples in Table 1 and other comparative examples was measured with a load cell.

When the pulling force was 525 kg, the pulling force was 105, and when the pulling force was 550 kg, the pulling force was 110.
The measurement of uneven wear and cracks is performed by operating the test machine and the track belt until the partial wear and cracks are generated under the condition that the crawler moving speed of the test machine is 10% higher than the belt moving speed of the track belt. At this time, the testing machine is connected to the column by a rope. The uneven wear and cracks are inspected for the presence of uneven wear and cracks by stopping the tester and the track belt and visually observing each time a predetermined time elapses.

The numerical values of uneven wear and cracks in Table 1 indicate that uneven wear and cracks in each elastic crawler 1 are observed with respect to the respective accumulated operating time until the partial wear and cracks of the conventional elastic crawler are observed. The case where the accumulated operation time until 10% is 10% or more and less than 20% is 105, and the case where the accumulated operation time is 10% or more and less than 20% is 95. In addition, the case where the accumulated operating time until the partial wear and the crack in each elastic body crawler 1 are observed is longer than 20% is set to 110, and the case where the accumulated operating time is shorter than 20% is set to 90.
The overall evaluation was performed with respect to the evaluation of uneven wear, which is closely related to deformation and falling of the lugs.

From Table 1, the difference in hardness between the low hardness rubber and the high hardness rubber 20a, 20b is 10 degrees or more and 25 degrees or less in durometer hardness, and at the same time, the arrangement of the high hardness rubbers 20a, 20b is L ÷ H (L / The elastic crawler 1 in which H) was 0.6 or more and 0.95 or less and W1 ÷ W (W1 / W) was 2.5 or more and 3.6 or less had good results in traction force and partial wear. I understand.
In this manner, by embedding rubber having a higher hardness than the other parts at the bottoms of the lugs 3a and 3b, uneven wear (falling of the lugs) can be suppressed. In the elastic crawler 1, only a small amount of hard rubber is embedded in the bottom of the lugs 3a and 3b as compared with other portions, so that there is no mistake in securing a storage place such as a two-layer tread or in molding.

Further, when rubber having a hardness higher than that of other portions is embedded on the outer peripheral side of the core metal 4, there is an effect of pressing the core metal 4, and the inclination of the core metal 4 and the floating of the core metal 4 can be prevented.
The elastic body crawler 1 suppresses a reduction in traction force, uneven wear, cracks, and the like due to the falling of the lug.
And the tension | tensile_strength of the tension bodies 5 and 5 by the inclination of the metal core 4 being lose | eliminated, and the uniformity of the width direction of the rubber | gum thickness under a wheel can be aimed at.
In the above-described embodiment, the shape and type of the core metal 4, the shapes of the lugs 3a and 3b, and the like can be changed. For example, instead of alternately arranging two types of lugs, the long lugs 3a and the short lugs 3b, in the circumferential direction, only the long lugs 3a or only the short lugs 3b are superimposed on the cored bar 4 and arranged at equal intervals in the circumferential direction. It may be an elastic crawler.

Instead of the high-hardness rubbers 20a and 20b, a resin having rubber-like elasticity and having a hardness comparable to that of the high-hardness rubbers 20a and 20b, such as polyurethane, may be used.
In addition, each structure of the elastic body crawler 1 and the elastic body crawler 1 or the whole structure, shape, dimensions, number, material, and the like can be appropriately changed in accordance with the spirit of the present invention.

  The present invention can be used for an elastic crawler mounted on a crawler type traveling vehicle.

FIG. 1 is a view of an elastic crawler viewed from the grounding side. 2 is a cross-sectional view taken along line AA in FIG. 3 is a cross-sectional view taken along the line BB in FIG. FIG. 4 is a cross-sectional view corresponding to FIG. 3 in the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic body crawler 2 Crawler main body 3a Lug (long lug)
3b rug (short rug)
4 Core 13 Outer surface (outer surface)
20a, 20b High hardness part (high hardness rubber)

Claims (2)

A crawler body formed in an endless belt shape by an elastic body;
A plurality of metal cores embedded in the crawler body at intervals in the circumferential direction of the crawler body,
On the outer peripheral surface of the crawler body,
A plurality of lugs protruding outward and extending in the width direction of the crawler body are integrated at a position where they overlap with any one of the different core bars in the circumferential direction,
The base where the lug is continuous with the crawler body and the vicinity in the circumferential direction are high-hardness portions formed of an elastic body having a high hardness W1 and extending in the width direction compared to other portions,
The difference in hardness between the other part and the high hardness part is 10 degrees or more and 25 degrees or less,
The ratio (L / H) between the distance L from the protruding end of the lug to the high hardness part and the height H of the lug is 0.6 or more and 0.95 or less,
And the ratio (W1 / W) between the width W1 of the high hardness portion and the thickness W in the circumferential direction of the lug at a half of the height H of the lug is 2.5 or more and 3.6 or less. A featured elastic crawler. The elastic crawler according to claim 1, wherein the high hardness portion is formed of a resin having rubber-like elasticity.

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