JP2001048067A - Rubber crawler and core bar used for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber crawler improved in the durable life and a core bar used for the rubber crawler. SOLUTION: This crawler is constituted of a rubber elastic body constituting a main body of a rubber crawler, a core bar l which is buried in the rubber elastic body and is buried toward a width direction for a traveling direction of the crawler and a rubber lug 24 formed on an outer peripheral surface of the rubber elastic body. In the rubber crawler, bent parts A toward the inner peripheral side are formed at both end parts of the width direction of the core bar 1 and a radius R1 of the bend part A is made 10 mm or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rubber crawler having improved durability and a metal core used for the same.

[0002]

2. Description of the Related Art As a rubber crawler 50 which has been widely used in the past, as shown in FIG.
The steel cord 53 surrounds the metal core 52 and is embedded in the longitudinal direction of the endless rubber elastic body 51. The core metal 52 has a length less than the entire width of the rubber elastic body 51, and is a so-called endless rubber elastic body 51.
Left and right sides constitute ears 54 made of only rubber material. Therefore, since the ear 54 is the most flexible in the rubber crawler 50 as a whole, the ear 54 is most likely to be deformed and distorted from the viewpoint of the usage of the rubber crawler 50.

However, when the conventional rubber crawler 50 comes into contact with the edge of the curb 60 or the like as shown in FIG. As a result, the ear portion 54 where the core bar 52 does not exist is significantly deformed, and a crack 61 is formed near the tip end portion 55 of the core bar 52 by repeating this deformation.

When the crack 61 enters, the core metal 52
Cracks 61 grow in the longitudinal direction of the rubber crawler 50 along the steel cord row 53 that surrounds. Then, assuming a use condition in which the rubber crawler 50 frequently contacts the curb 60 or the like, the ear 54 of the rubber crawler 50 may be cut along the longitudinal direction of the rubber crawler 50 in some cases.

Further, when the rubber crawler 50 rides on the stone 60 and causes a so-called reverse bending, a crack occurs at a portion of the rubber crawler 50 corresponding to the front and rear ends of the cored bar 52. These phenomena are also the same in so-called crawler rubber shoes mounted on the grocer surface of an iron shoe.The widthwise end of the core metal embedded in the rubber shoe and the end in the front-rear direction become edges and the rubber Cracks enter the crawler and shorten its life as a crawler.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rubber crawler which reduces the occurrence of cracks at the front and rear ends of the metal core, and a metal core used for the rubber crawler. Things. Needless to say, the rubber track referred to in the present invention also includes a crawler belt rubber shoe crawler.

[0007]

Means for Solving the Problems A core metal and a rubber crawler of the present invention have been made to solve the above-mentioned problems, and the first invention of the first invention relates to the structure of a rubber crawler, A rubber elastic body constituting a main body of the rubber crawler, a core metal embedded in the rubber crawler and buried in a width direction with respect to a traveling direction of the crawler, and a rubber lug formed on an outer peripheral surface of the rubber elastic body. The rubber crawler is characterized in that a bent portion A is formed at both ends in the width direction of the core bar toward the inner peripheral side, and the radius R1 of the bent portion A is 10 mm or more.

A second aspect of the first invention is a rubber elastic body constituting a main body of a rubber crawler, a core metal embedded in the rubber crawler and embedded in a width direction with respect to a traveling direction of the crawler, and A steel cord row surrounding the core metal and buried in the longitudinal direction of the rubber elastic body, and a rubber lug formed on the outer peripheral surface of the rubber elastic body, at both ends in the width direction of the core metal. The present invention relates to a rubber crawler, wherein a bent portion A is formed toward an inner peripheral side, and a radius R1 of the bent portion A is set to 10 mm or more.

According to the first aspect of the present invention, as a configuration further characterizing this, the radius R1 of the bent portion A is set to 15 m.
m or more, and it is preferable that the upper end surface of the bent portion A protrudes inward from the widthwise central portion of the cored bar.

[0010] The second invention relates to the structure of the rubber crawler as in the first invention. The first is a rubber elastic body constituting the main body of the rubber crawler and the rubber elastic body embedded in the rubber crawler in the running direction of the crawler. On the other hand, a bent portion B is formed at the front and rear ends in the traveling direction of the core bar, which comprises a core bar embedded in the width direction and a rubber lug formed on the outer peripheral surface of the rubber elastic body. And the radius R2 of the bent portion B is 10
mm or more.

A second aspect of the second invention is a rubber elastic body constituting a main body of a rubber crawler, a core metal embedded in the rubber crawler and embedded in a width direction with respect to a traveling direction of the crawler, and It consists of a steel cord row surrounding the core metal and buried in the longitudinal direction of the rubber elastic body, and rubber lugs formed on the outer peripheral surface of the rubber elastic body. The present invention relates to a rubber crawler, wherein a bent portion B directed toward the inner peripheral side is formed, and a radius R2 of the bent portion B is set to 10 mm or more.

A third aspect of the present invention relates to a core metal of a rubber crawler, in which a bent portion A is formed at the tip of the left and right wing portions toward the inner peripheral side of the rubber crawler, and a radius R1 of the bent portion A is set to one.
A rubber crawler core bar having a length of 0 mm or more, or a bent portion B toward the inner peripheral side of the rubber crawler formed at the front and rear ends of the left and right wing portions, and a radius R2 of the bent portion B
Is set to 10 mm or more.

In the present invention, the bent portion A and the bent portion B may be formed independently, but it is preferable that they are formed at the same time to form a ship bottom-shaped portion with an inner side hollowed out. Although the present invention is simply referred to as a rubber crawler, it includes a so-called crawler crawler rubber shoe crawler mounted on a grocer surface of an iron shoe.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a rubber crawler for preventing cutting of ears and a metal core used for the crawler.
By devising the tip of the core metal wing, cracks in the rubber material ears are prevented, and furthermore, cutting of the ears from cracks from the front and rear ends of the metal core wings is prevented.

The tip and front and rear ends of the wing portion of a normal cored bar are cut substantially vertically, and the edge portion is quite sharp. When this core metal is adopted for a rubber crawler, as described above, the core metal is sandwiched between the tip of the wing portion of the core metal and the curb, and the deformation stress is repeated at the ear portion. Cracks are formed toward the left and right end portions of the gold wings, and cracks are also formed at the front and rear ends of the metal core wings, leading to cutting of the ears.

In order to solve this problem, the present invention is devised at the tip of the wing, and the grounding side surfaces at the front and rear and / or both ends in the width direction of the metal core are directed toward the inner peripheral side of the rubber track. In particular, as a representative of the core metal according to the third aspect of the invention, the bent portion A and / or the bent portion is formed from the tip and / or front and rear ends of the wing portion to the inner circumferential side of the rubber crawler. The curved portion B is formed. The radius R1 of the bent portion A and / or the radius R2 of the bent portion B are set to 10 mm or more. Therefore, even when the rubber crawler using this core metal rides on an obstacle on the running surface, the thickness of the rubber material that is vulcanized and bonded to the ground side of the core metal wing portion is thicker, Since the force is reduced by the radius of the bent portion, even if the rubber material is in contact with the curb and the like and is pinched, the rubber material is thick and R
, The shear stress is dispersed. In addition, the bent portion of the metal core exhibits little shear deformation applied to the rubber material and exhibits almost only a compressive deformation. For this reason, the occurrence of rubber cracks is reduced, and cutting of the ears is prevented. If the radius R1 of the bent portion A or the radius R2 of the bent portion B of the cored bar is not more than 10 mm, the above-mentioned effects cannot be obtained, and it is preferably 15 mm or more. or,
The upper limits of R1 and R2 are naturally determined from the size of the cored bar.

By forming a hole-shaped or concave-shaped front and back through-hole in the bent portion A or B, rubber members to be vulcanized and bonded on both sides are united through the through-hole to further prevent peeling, In addition, the weight of the core metal in the penetrating portion is reduced, which contributes to weight reduction.

Furthermore, if the bent portions A and B are simultaneously formed in the cored bar to form the bottom of the ship with a hollow inside, when the rubber crawler is buried in the rubber crawler, it is added to the front and rear direction and the lateral direction of the rubber crawler. Even when a force is applied in an oblique direction, the occurrence of cracks is extremely reduced because there is no edge around the metal core. The bent portions A and B are preferably integrated, but may be separated and independent as a matter of course.

In particular, regarding the rubber track of the first and second inventions, in particular, a rubber track using a steel cord row which embeds the above-mentioned core metal in the rubber track and further surrounds the wing portion of the core metal. Preferably, the position of the outer end is specified. That is, when the outer end of the steel cord row is arranged near the tip of the wing portion of the cored bar, when the ear part is cracked, the crack easily reaches the steel cord at the outer end. Then, the crack grows in the longitudinal direction of the rubber crawler along the steel cord, which results in the cutting of the ear part. However, the outer end of the steel cord row is placed 15 m from the tip of the wing part of the cored bar.
Even if a crack occurs at the end of the cored bar if it is at least 20 m or more, preferably at least 20 mm inside, it does not reach the steel cord row, so that crack growth in the longitudinal direction of the rubber crawler is prevented. Will be done.

The rubber crawler is generally provided at a position where the metal core and the rubber lug are opposed to each other, but it is usually preferable that the ground surface of the rubber lug completely covers the flat surface of the metal core. Thus, there is no portion with a small amount of rubber against deformation, and the life is further improved.

[0021]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is an inner plan view showing a core of the third invention, and FIG. 2 is a partially cut front view thereof. In the figure, reference numeral 1 denotes a metal core, and a central portion thereof is a sprocket engaging portion 2. Wings 3 are formed on the left and right sides, and a pair of corners 4 are arranged in a staggered manner with the sprocket engaging portion 2 interposed therebetween. At the tip of the wing portion 3 of the cored bar 1, a bent portion A having a radius R <b> 1 and a bent portion B at the front and rear ends 5 of the wing portion 3 are integrally raised toward the inner peripheral side of the rubber crawler. This forms the bottom part C of the ship.

This cored bar 1 is employed in the rubber track of the first and / or second invention. However, since the bottom part C is formed at the tip of the wing portion 3 of the cored bar 1, the cored bar 1 is formed. The bonding area with the rubber existing on the front and back is increased, so the bonding strength is increased, and even when the rubber crawler is sandwiched between curbs, the shearing force is not concentrated on the rubber material (ears), and cracks are generated and Based on this, the cutting of the ears and the occurrence of cracks at the front and rear ends of the wings 3 of the metal core 1 are reduced. That is, the thickness of the rubber material on the ground side of the vulcanized and bonded rubber material is increased by that much, and the thickness of the rubber material is large even when the ear is sandwiched between the curb and the shearing force. Are dispersed to that extent, and the occurrence of cracks is reduced.

Even when an excessive force is applied to the rubber crawler in the lateral or oblique direction, no sharp edge exists because the bent portion B is formed at the front and rear ends 5 of the metal core wing portion 3 and this bent portion does not exist. The wings 3 of the cored bar 1 are used for the curved portion B to resist the force.
The occurrence of cracks at the edges is reduced.

The specific shape of the metal core 1 is as follows.
For example, the length between the tips of the wings 3, 3 is 290 mm,
5 is 30 mm in width, the sprocket engagement portion 2 between the corner portions 4 and 4 is 46 mm, the height from the lower portion is 27 mm, and the wing portion 3 following this is 122 mm. The thickness near the tip of the wing portion 3 is about 3.7 mm. In addition, the corner 4 has a width of 1 at the top.
It is 5 mm in height and 50 mm in height from the bottom, and has a structure in which a rib 6 is formed from the wing 3 to the corner 4. The radius R1 of the bent portion A at the tip of the wing 3 is 20
mm. Further, at the front and rear ends 5 of the wing portion 3, a bent portion B is formed integrally with the bent portion A from a portion approximately 50 mm from the tip. In the drawing, reference numerals 7 and 8 denote penetrating portions provided on the bent portion A and penetrating from the front and back, respectively. The penetrating portion 7 is a hole, and the penetrating portion 8 is a recess.

FIG. 3 is an inner plan view showing one example of the rubber track of the first invention (claim 2), FIG. 4 is an outer plan view, and FIG.
FIG. 3 is a sectional view taken along line AA. In the figure, reference numeral 21 denotes an endless rubber elastic body which forms a base of the rubber crawler 20. The core metal 1 is embedded at a constant pitch, and a steel cord surrounds the wing portion 3 of the core metal 1. Row 22
Are also buried in the longitudinal direction of the rubber elastic body 21.
Therefore, the ear 23 made of only the rubber material is formed outward from the tip of the wing 3 of the cored bar 1. Reference numeral 24 denotes a rubber lug formed on the outer peripheral side of the rubber elastic body 21, and a sprocket engagement hole 25 is formed in the center.

The core 1 used here has the above-mentioned structure, and the tip of the wing portion 3 of the core 1 is
A bent portion A and a bent portion B are formed toward the inner peripheral side of the hull to form a hull portion C. Therefore, the thickness of the rubber material outside (bottom side) of the hull bottom portion C is larger than usual. ing. In this example, the rubber raised portion 26 is provided continuously in the longitudinal direction of the rubber crawler 20 so as to cover the bottom portion C of the ship. The lug 24 preferably covers the flat portion of the wing portion 3 of the cored bar 1. In the illustrated example, the lug 24 has a shape that covers the entire portion including the bottom shape portion C.

Since the thickness of the rubber material generally contributes to the relaxation of the stress with respect to the deformation of the rubber material, the rubber crawler 20 comes into contact with the curbstone and has the ear 2
Even if the deformation of No. 3 is repeated, the concentration of the stress is relieved, and the occurrence of cracks is not observed. The outer end of the steel cord row 22 is at a predetermined distance (L) from the tip of the wing portion 3. However, even if a crack should occur, the crack does not reach the steel cord row 22 and the growth of the crack in the longitudinal direction of the rubber crawler 20 is not observed. The inside (L) of the steel cord row 22 is about 15 mm in a normal rubber crawler, and 20 mm is sufficient even in consideration of a large rubber crawler. In the cored bar shown in the figure, by providing the bent portion A with the penetrating portion 7 (or 8), the rubber members on the front and back of the bent portion A are integrated here to help prevent peeling.

FIG. 6 is a plan view of the crawler belt rubber shoe crawl roller 30 of the first invention (claim 1), and FIG. 7 is a sectional view taken along the line BB. 8 is a plan view showing a part of the metal core 40, and FIG. 9 is a sectional view taken along line CC. In the figure, reference numeral 31 denotes a rubber elastic body, in which a metal core 40 is embedded, and 32 is a rubber lug formed corresponding to the metal core 40. In this example, a bolt hole 33 is drilled through the rubber lug 32 and the core bar 40, and the bolt hole 33 is mounted on an iron shoe (not shown) using this. In this example, both ends of the cored bar 40 have the same bottom shape C as in the previous example.
Needless to say, the tip is a straight edge portion 41.

Even in this example, the radius R is
Therefore, the front and rear ends 42 of the metal core 40 are similarly formed with a bent portion B on the inner peripheral side corresponding to the bent portion A, so that the bottom portion C is formed. , The strain concentrated on the front end and front and rear ends 42 of the metal core 40 is reduced.
By forming the bottom shape C on the inner peripheral side of this, the strain was dispersed by that much and the thickness of the rubber covering this was also increased, and the occurrence of cracks from this portion could be prevented. is there. Reference numeral 36 denotes an inclined surface of the rubber lug 32 at the width end, and reference numeral 37 denotes a rubber protrusion.

Hereinafter, still another specific example of the cored bar according to the third invention will be described. Of course, these cores are also employed as they are in the first and second inventions. FIG. 10 is a plan view of the cored bar in this example, FIG. 11 is a side view thereof, and FIG. 12 is a front view thereof. Here, the radius R1 of the bent portion A and the radius R2 of the bent portion B are both 20 mm, and the bottom portion C is hollowed out. Also, the upper end surface T of the bent portion A
Is a flat surface having a width of 18 mm, and protrudes 11 mm inward from the widthwise central portion of the cored bar 40.
In addition, it is preferable that the width of the upper end surface T of the bent portion A be 5 mm or more. This is because rubber deformation near the upper surface of the bent portion A can be suppressed.

FIG. 13 is a plan view of the crawler belt rubber shoe crawler 30 using the cored bar shown in FIGS. 10 to 12, wherein the upper half is an inner plan view and the lower half is an outer plan view. FIG. 14 is a side view thereof (only the left half is shown due to symmetry),
FIG. 15 is a front view thereof. In the figure, reference numeral 31 denotes a rubber elastic body, and a core metal 40 is embedded in the rubber elastic body 31. Then, in this example, it is mounted on an iron shoe (not shown) using the bolt hole 33.

In this example, the bent portion A and the bent portion B are formed at the same time, and the core metal 40 having the bottom-shaped portion C hollowed out is used. Only the weight of the crawler rubber shoe crawler 30 is reduced.
In addition, due to the presence of the bent portions A and B, the number of times of running before climbing on the fixed stone and generating a crack at the end of the cored bar is 25 times as compared with the crawler belt rubber shoe crawler using the conventional cored bar having no bent portion. It was twice as long, and the durability was greatly improved.

[0033]

The core metal and the rubber crawler of the present invention are intended to prevent cutting occurring in each direction of the ears of the rubber crawler, and are provided at both ends in the width direction of the core metal with a rubber material sandwiched between curbs and the like. The generation of cracks is prevented by reducing the radius of the bent portion and / or the bent portion at the front and rear ends in the traveling direction to a predetermined value or more, and cutting of the ear portion is reduced, and the effect is large.

[Brief description of the drawings]

FIG. 1 is an inside plan view showing a cored bar according to a third invention.

FIG. 2 is a partially cut front view of FIG. 1;

FIG. 3 is an inside plan view showing an example of the rubber track of the first invention.

FIG. 4 is an outside plan view of FIG. 3;

FIG. 5 is a sectional view taken along line AA of FIG. 3;

FIG. 6 is a plan view of the crawler rubber shoe crawler of the first invention.

FIG. 7 is a sectional view taken along line BB of FIG. 6;

FIG. 8 is a plan view showing a part of the metal core used in FIG. 6;

FIG. 9 is a sectional view taken along line CC in FIG. 8;

FIG. 10 is a plan view showing another example of the core metal used in the crawler rubber shoe crawlers of the first and second inventions.

FIG. 11 is a side view of FIG. 10;

FIG. 12 is a front view of FIG. 10;

FIG. 13 is a plan view showing a crawler belt rubber shoe crawler using the cored bar shown in FIGS. 10 to 12.

FIG. 14 is a side view of FIG. 13;

FIG. 15 is a front view of FIG. 13;

FIG. 16 is a sectional view showing the structure of a conventional rubber track.

[Explanation of symbols]

 1 ‥ core metal, 3 ‥ core wing, 5 ‥ wing front and rear end, 7, 8 ‥ penetration, 20 ‥ rubber crawler, 21 ‥ endless rubber elastic body, 22 ‥ steel cord row, 23 ‥ ear Part, 24 ‥ rubber lug, 26 ‥ rubber protrusion, 30 ‥ rubber crawler, 31 ‥ rubber elastic body, 32 ‥ rubber lug, 37 ‥ rubber protrusion, 40 ‥ core, 42 金 front and rear end of core, A ‥ wing B ‥ Bends at the front and rear ends of the wing in the advancing direction of the wing, C ‥ Bottom of the wing, R1 ‥ Bend A radius, R2 ‥ Bend radius B , T ‥ The upper end surface of the bent portion A.

Claims (12)

[Claims] 1. A rubber elastic body constituting a main body of a rubber crawler, a core metal embedded in the rubber crawler and buried in a width direction with respect to a traveling direction of the crawler, and formed on an outer peripheral surface of the rubber elastic body. A rubber crawler, comprising a bent portion A formed at both ends in the width direction of the metal core and having a radius R1 of 10 mm or more. 2. A rubber elastic body constituting a main body of a rubber crawler, a core bar embedded in the rubber crawler and buried in a width direction with respect to a traveling direction of the crawler, and the rubber surrounding the core bar. A bent portion A is formed of a steel cord row buried in the longitudinal direction of the elastic body and a rubber lug formed on the outer peripheral surface of the rubber elastic body. And the radius R1 of the bent portion A is set to 1
A rubber crawler having a length of 0 mm or more. 3. The rubber track according to claim 1, wherein a radius R1 of the bent portion A is 15 mm or more. 4. The rubber track according to claim 1, wherein an upper end surface of the bent portion A protrudes inward from a widthwise central portion of the cored bar. 5. A rubber elastic body constituting a main body of a rubber crawler, a core metal embedded in the rubber crawler and embedded in a width direction with respect to a traveling direction of the crawler, and formed on an outer peripheral surface of the rubber elastic body. A rubber crawler, comprising a bent portion B which is formed at the front and rear ends in the traveling direction of the core metal, and has a radius R2 of 10 mm or more. 6. A rubber elastic body constituting a main body of a rubber crawler, a core bar embedded in the rubber crawler in a width direction with respect to a traveling direction of the crawler, and the rubber surrounding the core bar. A bent portion B comprising a steel cord row buried in the longitudinal direction of the elastic body and a rubber lug formed on the outer peripheral surface of the rubber elastic body is formed at the front and rear ends in the traveling direction of the core metal toward the inner peripheral side. And a radius C2 of the bent portion B is set to 10 mm or more. 7. The rubber track according to claim 5, wherein a radius R2 of the bent portion B is 15 mm or more. 8. The rubber track according to claim 5, wherein an upper end surface of the bent portion B protrudes inward from a center portion of the cored bar in the traveling direction. 9. A rubber elastic body constituting a main body of a rubber crawler, a core metal embedded in the rubber crawler and embedded in a width direction with respect to a traveling direction of the crawler, and formed on an outer peripheral surface of the rubber elastic body. A bent portion A is formed at both ends in the width direction of the core metal toward the inner peripheral side, and a bent portion B is formed at the front and rear ends in the traveling direction of the core metal toward the inner peripheral side. The ship bottom shape part which the inside was hollowed out.
Rubber crawler according to the item. 10. A rubber elastic body constituting a main body of a rubber crawler, a core metal embedded in the rubber crawler and buried in a width direction with respect to a traveling direction of the crawler, and the rubber material surrounding the core metal. A bent portion A is formed of a steel cord row buried in the longitudinal direction of the elastic body and a rubber lug formed on the outer peripheral surface of the rubber elastic body. 7. The rubber crawler according to claim 2, wherein a bent portion B is formed at the front and rear ends of the metal core in the advancing direction, and the bent portion B is directed toward the inner peripheral side to form a ship bottom-shaped portion having an inner side hollowed out. 11. A rubber crawler core bar buried in the width direction of the rubber crawler, wherein a bent portion A toward the inner peripheral side of the rubber crawler is formed at the tip of each of the left and right wing portions. A core for a rubber track, wherein a radius R1 of the curved portion A is 10 mm or more. 12. A rubber crawler core bar buried in the width direction of the rubber crawler, wherein a bent portion B toward the inner peripheral side of the rubber crawler is formed at the front and rear ends of the left and right wing portions. A core for a rubber track, wherein a radius R2 of the bent portion B is 10 mm or more.