CN114104133A

CN114104133A - Elastic crawler belt

Info

Publication number: CN114104133A
Application number: CN202110901159.0A
Authority: CN
Inventors: 林优希
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 2020-08-28
Filing date: 2021-08-06
Publication date: 2022-03-01
Also published as: JP7484582B2; JP2022039389A

Abstract

The invention provides an elastic crawler belt (10) capable of contributing to low fuel consumption performance of a running device. The elastic crawler belt (10) comprises: a main portion (14) formed of an elastic material and having an endless belt shape; and a plurality of core rods (18) arranged in the circumferential direction at a predetermined pitch P. Each of the cores (18) is embedded in the main section (14). The ratio (S/(P-S)) of the circumferential dimension S of the core (18) to the distance (P-S) between the core (18) and the core (18) adjacent to the core is 0.40 or less. The ratio (Wc/Wm) of the width Wc of the core to the width Wm of the main portion is 0.40 to 0.60.

Description

Elastic crawler belt

Technical Field

The present invention relates to an elastic crawler of a running gear. More specifically, the present invention relates to a crawler including a main portion having an endless belt shape and a core embedded in the main portion.

Background

An elastic crawler of a running device has a main portion made of rubber or the like and having an endless belt shape, and a plurality of cores embedded in the main portion. An elastic crawler having a core is disclosed in japanese patent laid-open publication No. 2006-315628.

Patent document 1: japanese patent laid-open publication No. 2006-315628

The running gear has a drive wheel and a driven wheel. The elastic crawler belt is erected on the driving wheel and the driven wheel. The crawler belt is wound around the drive wheel and also around the driven wheel. The track curves at the drive and driven wheels. Due to this bending, stress occurs in the track. The track bends against this stress. The bending results in energy loss. The bending hinders low fuel consumption performance of the running gear.

As described above, the elastic crawler has a core. The density of the core is generally greater. The mass of the track with the core is greater. The large mass hinders low fuel consumption performance of the running gear.

Disclosure of Invention

The invention aims to provide an elastic crawler belt which can contribute to low fuel consumption performance of a running device.

The elastic crawler according to the present invention comprises:

(1) a main portion formed of an elastic material and having a ring belt shape; and

(2) the plurality of cores are arranged in the circumferential direction at a predetermined pitch P.

Each of the core bars is embedded in the main portion. The ratio (S/(P-S)) of the circumferential dimension S of the core to the distance (P-S) between the core and the core adjacent to the core is 0.40 or less. The ratio (Wc/Wm) of the width Wc of the core to the width Wm of the main portion is 0.40 to 0.60.

Preferably, the ratio (S/Wc) of the circumferential dimension S of the core to the width Wc is 0.10 to 0.20.

Preferably, the ratio (S/(P-S)) is 0.30 or less. Preferably, the ratio (Wc/Wm) is 0.40 or more and 0.50 or less.

The core may have a central portion and a wing extending outward in the width direction from the central portion. Preferably, a ratio (T/S) of a thickness T of the blade at a boundary between the central portion and the blade to a circumferential dimension S of the core is 0.20 or more and 0.40 or less.

The material of the main portion may be a crosslinked rubber. Preferably, the main portion has A JIS-A hardness of 65 or more and 80 or less.

Drawings

Fig. 1 is a schematic view showing a running apparatus including an elastic crawler according to an embodiment of the present invention.

Fig. 2 is an enlarged view showing an outer peripheral surface of the crawler belt of fig. 1.

Fig. 3 is an enlarged view showing an inner peripheral surface of the crawler belt of fig. 1.

Fig. 4 is a sectional view taken along line IV-IV of fig. 2.

Fig. 5 is a sectional view taken along line V-V of fig. 2.

Fig. 6 is an enlarged cross-sectional view showing a portion of a core of the elastic crawler of fig. 4.

Description of the reference numerals

2 … driving device; 4 … driving the wheels; 6 … driven wheel; 10 … elastic track; 14 … a main portion; 16 … bumps; 18 … mandril; 20 … a wheel guide; 22 … a stretch body; 24 … outer peripheral surface; 26 … inner peripheral surface; 30 … snap-fit hole; 34 … center portion; 36 … wing; 38 … protrusions; 40 … head; 42 … cord.

Detailed Description

The present invention will be described in detail below based on preferred embodiments with reference to the accompanying drawings as appropriate.

Fig. 1 shows a travel device 2. The traveling device 2 includes a drive wheel 4, a driven wheel 6, a plurality of wheels 8, and an elastic crawler 10. The drive wheels 4 and the driven wheels 6 are main wheels 12. The traveling device 2 includes a drive unit (engine, etc.), not shown. By means of which the drive wheel 4 is rotated. The drive wheel 4 is typically a sprocket. The crawler belt 10 is mounted on the driving wheel 4 and the driven wheel 6. The crawler belt 10 is wound around the drive wheel 4 and also around the driven wheel 6. By the rotation of the drive wheel 4, the crawler belt 10 rotates. As the track 10 rotates, the wheels 8 guide the track 10. By this guide, meandering of the crawler belt 10 is prevented. The device 2 travels by the rotation of the crawler belt 10. Typical traveling devices 2 include civil engineering equipment, construction equipment, and agricultural equipment. The running gear 2 may also have a plurality of driven wheels 6. The running gear 2 may also have a wheel 8 between the driven wheel 6 and the other driven wheels 6.

An elastomeric track 10 is shown in fig. 2-5. The outer circumferential surface of the crawler 10 is shown in fig. 2, and the inner circumferential surface of the crawler 10 is shown in fig. 3. Fig. 4 is a sectional view taken along line IV-IV of fig. 2, and fig. 5 is a sectional view taken along line V-V of fig. 2. In each drawing, arrow X indicates the width direction, arrow Y indicates the circumferential direction, and arrow Z indicates the thickness direction. The elastic crawler 10 has a main portion 14, a plurality of lugs (lug)16, a plurality of cores 18, a plurality of wheel guides 20, and a pair of tensile members 22.

The main portion 14 has an endless belt shape. The main portion 14 has an outer peripheral surface 24 and an inner peripheral surface 26. The main portion 14 also has a pair of outer edges 28. The width of the main portion 14 is shown by the arrow Wm in fig. 2. The width Wm is the distance from one outer edge 28 to the other outer edge 28. The width Wm of the main portion 14 is also the width of the crawler belt 10. The width Wm of the general elastic crawler belt 10 is 100mm to 600 mm. The main portion 14 has a plurality of engagement holes 30. When the crawler belt 10 travels, the claws 32 (see fig. 1) of the drive wheels 4 enter the engagement holes 30. The claws 32 transmit driving force from the driving wheel 4 to the crawler belt 10. The main portion 14 may have a recess instead of the engagement hole 30. In the main portion 14, the claws 32 press the concave portions. The claws 30 may also directly press against the protrusion of the core 18.

The main portion 14 is formed of an elastic material. Rubber, synthetic resin, elastomer, or the like can be used for the main portion 14. The material of the main portion 14 is typically a crosslinked rubber composition. Typical main sections 14 have a density of from 0.8g/cm³To 2.0g/cm³。

As shown in fig. 2, the plurality of bumps 16 are arranged in the circumferential direction. These bumps 16 are arranged at equal intervals. In the present embodiment, the elastic crawler 10 has a plurality of left lugs 16a and a plurality of right lugs 16 b. The left and

right bumps

16a and 16b are alternately arranged in the circumferential direction. The left end of each left tab 16a coincides with the outer edge 28 of the left side. The right end of each right projection 16b coincides with the outer edge 28 of the right side. The right projection 16b has a shape in which the shape of the left projection 16a is mirror-inverted.

As shown in fig. 4 and 5, each of the projections 16 projects from the outer peripheral surface 24 of the main portion 14. The material of the bump 16 is different from that of the main portion 14. The material of the bump 16 may be the same as that of the main portion 14.

As shown in fig. 2 and 3, the plurality of mandrels 18 are arranged in the circumferential direction. These core bars 18 are arranged at equal intervals. Each of the mandrels 18 is positioned at the center in the width direction. In the present embodiment, the core 18 has a bilaterally symmetrical shape. The core 18 may also have a shape that is not left-right symmetrical. As shown in fig. 4, the core 18 has a central portion 34, a pair of wings 36, and a pair of projections 38. Each wing 36 extends from the central portion 34 toward the widthwise outer side. Each projection 38 projects inwardly from the central portion 34. The central portion 34, the wings 36, and the protrusions 38 are integrally formed.

The core 18 is made of a hard material. The material of the core bar 18 is typically steel, stainless steel, or other metal. The typical density of the core 18 is from 3.0g/cm³To 10.0g/cm³。

As is clear from fig. 4, the core bar 18 is embedded in the main portion 14. A portion of the core 18 may also be exposed from the main portion 14. In the present invention, the case where a part of the core bar 18 is exposed from the main portion 14 is also referred to as "embedding".

As shown in fig. 3, the plurality of wheel guides 20 are arranged in the circumferential direction. These wheel guides 20 are arranged at equal intervals. Each wheel guide 20 is located at the widthwise center. As shown in fig. 4 and 5, the wheel guide 20 protrudes from the inner peripheral surface 26 of the main portion 14. The wheel guide 20 has a pair of heads 40. Each head 40 contains a protrusion 38 of the core 18. The head 40 also comprises a portion of the main portion 14. The head 40 may also not contain the main portion 14. In other words, the core 18 may also be exposed in the head 40.

As shown in fig. 5, each tensile member 22 has a plurality of cords 42. Each cord 42 extends in the circumferential direction. This cord 42 can suppress excessive elongation of the main portion 14. Typical materials of the cord 42 are metals such as steel and stainless steel. The cord 42 may also be formed of an organic fiber.

As shown in fig. 1, the elastic crawler 10 is curved by being wound around the main wheel 12. In the curved crawler belt 10, the vicinity of the inner peripheral surface 26 of the main portion 14 contracts, and a compressive stress is generated in the vicinity of the inner peripheral surface 26. In the curved crawler belt 10, the vicinity of the outer peripheral surface 24 of the main portion 14 is elongated, and tensile stress is generated in the vicinity of the outer peripheral surface 24.

Even in a state where the elastic crawler 10 is wound around the main wheel 12, the core 18 cannot be bent. Therefore, bending occurs at a portion 44 (hereinafter referred to as "a clamping portion". refer to fig. 3.) clamped by the core 18 and the core 18 adjacent thereto.

In fig. 3, an arrow P indicates the pitch of the core members 18, and an arrow S indicates the circumferential dimension of the core members 18. The dimension S is measured on the wing 36 (see fig. 4). The arrow (P-S) is the circumferential distance of the clamping portion 44. The distance (P-S) is also the spacing of the core 18 from the core 18 adjacent thereto. The pitch P and the distance (P-S) are measured in the circumferential direction in a state where the crawler belt 10 is not bent.

As described above, the bending is mainly generated in the nip portion 44. In the crawler belt 10 in which the distance (P-S) between the clamping portions 44 is sufficiently large, stress due to bending is small. The crawler belt 10 can be easily bent. In the crawler belt 10, energy loss due to bending is small. The crawler belt 10 can contribute to low fuel consumption of the running gear 2.

From the viewpoint of fuel economy performance, the ratio (S/(P-S)) of the circumferential dimension S to the distance (P-S) is preferably 0.40 or less, more preferably 0.35 or less, and particularly preferably 0.30 or less. From the viewpoint of durability of the core 18 and rigidity of the crawler belt 10, the ratio (S/(P-S)) is preferably 0.20 or more.

In fig. 4, an arrow Wm indicates the width of the main portion 14, and an arrow Wc indicates the width of the core bar 18. The width Wm may be the width of the elastic crawler 10. The ratio of the width Wc to the width Wm (Wc/Wm) is preferably 0.60 or less. As described above, the main portion 14 is made of an elastic material, and the core 18 is made of metal. The density of the core 18 is greater than that of the main portion 14. The crawler belt 10 is light in weight with a ratio (Wc/Wm) of 0.60 or less. The crawler belt 10 is excellent in fuel economy. From this viewpoint, the ratio (Wc/Wm) is more preferably 0.55 or less, and particularly preferably 0.50 or less. From the viewpoint of rigidity and durability of the crawler belt 10, the ratio (Wc/Wm) is preferably 0.40 or more.

The ratio (S/Wc) of the circumferential dimension S of the core 18 to the width Wc is preferably 0.10 to 0.20. The core 18 having the ratio (S/Wc) of 0.10 or more has excellent strength although the ratio (Wc/Wm) is small. From this viewpoint, the ratio (S/Wc) is more preferably 0.12 or more, and particularly preferably 0.13 or more. The crawler belt 10 having the ratio (S/Wc) of 0.20 or less is excellent in durability and light in weight. From these viewpoints, the ratio (S/Wc) is more preferably 0.18 or less, and particularly preferably 0.17 or less.

Fig. 6 is an enlarged cross-sectional view showing a portion of the core 18 of the elastic crawler 10 of fig. 4. In fig. 6, the central portion 34, the wings 36 and the protrusions 38 are shown. Reference character Pb in fig. 6 is a boundary point of the central portion 34 and the wing 36. The boundary point Pb is an intersection between an extension of the upper side contour line Lu of the airfoil 36 and an extension of the outer side contour line Lo of the protrusion 38. The arrow T indicates the thickness of the wing 36 at the boundary point Pb.

The ratio (T/S) of the thickness T of the fins 36 to the circumferential dimension S of the core 18 is preferably 0.20 to 0.40. The core 18 having the ratio (T/S) of 0.20 or more has excellent strength although the ratio (Wc/Wm) is small. From this viewpoint, the ratio (T/S) is more preferably 0.23 or more, and particularly preferably 0.25 or more. The core 18 having a ratio (T/S) of 0.40 or less is lightweight. From this viewpoint, the ratio (T/S) is more preferably 0.37 or less, and particularly preferably 0.35 or less.

The ratio (T/Wc) of the thickness T of the wing 36 to the width Wc of the core 18 is preferably 0.03 to 0.08. The core 18 having a ratio (T/Wc) of 0.03 or more has excellent strength although the ratio (Wc/Wm) is small. From this viewpoint, the ratio (T/Wc) is more preferably 0.04 or more, and particularly preferably 0.05 or more. The core 18 having a ratio (T/Wc) of 0.08 or less is light in weight. From this viewpoint, the ratio (T/Wc) is more preferably 0.07 or less, and particularly preferably 0.06 or less.

The hardness of the main portion 14 is preferably 65 or more and 80 or less. The elastic crawler belt 10 having a hardness of 65 or more has excellent durability, although it has a core 18 having a smaller ratio (S/(P-S)) and a smaller ratio (Wc/Wm). From this viewpoint, the hardness is more preferably 68 or more, and particularly preferably 70 or more. The main portion 14 having a hardness of 80 or less is excellent in bendability. The crawler belt 10 having the main portion 14 is excellent in fuel efficiency. From this viewpoint, the hardness is more preferably 78 or less, and particularly preferably 76 or less. The hardness is measured by pressing A JIS-A type hardness meter against the main portion 14. The temperature at the time of measurement was 23 ℃.

As is apparent from fig. 2, 4 and 5, the elastic crawler 10 has no groove on the inner circumferential surface 26. Therefore, improvement in the bending property depending on the groove cannot be expected in this crawler belt 10. Nor can the light weight of the trough be relied upon in this track 10. However, in the crawler belt 10, the appropriate bendability is exhibited depending on the appropriate size of the core 18, and the weight is reduced. In the crawler belt 10 having no groove, vibration caused by the runner 8 being fitted into the groove is not generated. The crawler belt 10 is excellent in quietness. In the crawler belt 10 having no groove, adhesion of earth and sand to the inner peripheral surface 26 is less likely to occur. Therefore, damage due to the sand being pressed by the runner 8 is less likely to occur. The crawler belt 10 is excellent in durability. The crawler belt 10 is excellent in the balance of fuel economy performance, quietness, and durability. The inner circumferential surface 26 may have grooves.

The effects of the present invention will be clarified by the following examples, but the present invention should not be construed as being limited thereto.

[ experiment 1]

[ example 1]

An elastic crawler having the structure shown in fig. 1 to 6 was produced. The track has the following specifications.

Width Wm of main portion: 250mm

Pitch P: 90mm

Width Wc of the core bar: 120mm

Circumferential dimension S of the core bar: 20mm

Thickness T: 6mm

Hardness of the main portion: 75(JIS A)

[ examples 2 to 4]

Elastic crawler belts according to examples 2 to 4 were obtained in the same manner as in example 1, except that the hardness of the main portion was set as shown in table 1 below.

[ flexibility ]

And cutting the elastic crawler belt to obtain a test piece with a specified length. One end and the other end of the specimen are brought into contact to bend the vicinity of the center. The bending diameter in the vicinity of the center was measured, and the bendability was rated. The results are shown in table 1 below.

[ lightweight ]

The mass of the elastic crawler belt is measured, and the lightness is graded. The results are shown in table 1 below.

[ rigidity ]

The rigidity of the elastic crawler belt in the width direction was evaluated by sensory evaluation and rated. The results are shown in table 1 below.

[ TABLE 1]

TABLE 1 evaluation results

As shown in table 1, in the crawler belts of the respective examples, ratings of "a" or "B" were obtained in all the evaluation items.

[ experiment 2]

[ examples 5 to 7]

Elastic crawler belts according to examples 5 to 7 were obtained in the same manner as in example 1, except that the thickness T of the core was changed.

[ evaluation ]

The flexibility, lightness and rigidity of the elastic crawler were evaluated in the same manner as in experiment 1. The results are shown in table 2 below.

[ TABLE 2]

TABLE 2 evaluation results

As shown in table 2, in the crawler belts of the respective examples, ratings of "a" or "B" were obtained in all the evaluation items.

[ experiment 3]

Examples 8 and 9 and comparative examples 1 and 2

Elastic crawler belts of examples 8 and 9 and comparative examples 1 and 2 were obtained in the same manner as in example 1, except that the width Wc of the core was changed.

[ evaluation ]

The flexibility, lightness and rigidity of the elastic crawler were evaluated in the same manner as in experiment 1. The results are shown in table 3 below.

[ TABLE 3]

Table 3 evaluation results

As shown in table 3, in the crawler belt of comparative example 1, the rigidity was rated as "C". In the crawler belt of comparative example 2, the lightness was rated "C". On the other hand, in the crawler belts of the respective examples, the ratings of "a" or "B" were obtained in all the evaluation items.

[ experiment 4]

Examples 10 to 12 and comparative example 3

Elastic crawler belts of examples 10 to 12 and comparative example 3 were obtained in the same manner as in example 1, except that the dimension S of the core was changed.

[ evaluation ]

The flexibility, lightness and rigidity of the elastic crawler were evaluated in the same manner as in experiment 1. The results are shown in table 4 below.

[ TABLE 4]

Table 4 evaluation results

As shown in table 4, in the crawler belt of comparative example 3, the bending property was rated "C", and the lightweight property was rated "C". On the other hand, in the crawler belts of the respective examples, the ratings of "a" or "B" were obtained in all the evaluation items.

The advantages of the present invention can be understood from the evaluation results shown in tables 1 to 4.

Industrial applicability of the invention

The elastic crawler according to the present invention is suitable for various traveling apparatuses.

Claims

1. An elastic crawler belt, which is characterized in that,

the disclosed device is provided with:

a main portion formed of an elastic material and having a ring belt shape; and

a plurality of core bars arranged in a circumferential direction at a predetermined pitch P,

each of the core bars is embedded in the main portion,

the ratio (S/(P-S)) of the circumferential dimension S of the core to the distance (P-S) between the core and the core adjacent to the core is 0.40 or less,

the ratio (Wc/Wm) of the width Wc of the core bar to the width Wm of the main portion is 0.40 to 0.60.

2. The elastomeric track of claim 1,

the ratio (S/Wc) of the circumferential dimension S of the core to the width Wc is 0.10 to 0.20.

3. An elastomeric track according to claim 1 or 2,

the ratio (S/(P-S)) is 0.30 or less.

4. An elastomeric track according to any one of claims 1 to 3,

the ratio (Wc/Wm) is 0.40 to 0.50.

5. An elastomeric track according to any one of claims 1 to 4,

the core has a central portion and a wing extending outward in the width direction from the central portion,

the ratio (T/S) of the thickness T of the blade at the boundary between the central portion and the blade to the circumferential dimension S of the core is 0.20 to 0.40.

6. An elastomeric track according to any one of claims 1 to 5,

the main part is made of cross-linked rubber,

the main portion has A JIS-A hardness of 65 to 80.