Elastic crawler

Abstract

To provide an elastic crawler 32 that can suppress a tooth skip.SOLUTION: The elastic crawler 32 includes: a crawler main body 34; drive protrusions 36 that protrude inwardly from the crawler main body 34; and a lug 38 that protrudes outwardly from the crawler main body 34. This elastic crawler 32 includes an elastic body 42, and a plurality of core metals 44 covered by the elastic body 42. The core metals 44 are arranged side by side in the circumferential direction of the elastic crawler 32. Each core metal 44 includes: a base 48 included in the crawler main body 34; an internal protrusion 52 that protrudes inwardly from the base 48; and an external protrusion 54 that protrudes outwardly from the base 48. The internal protrusion 52 reinforces the drive protrusions 36. A part of the external protrusion 54 is located in the lug 38.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an elastic crawler, and more particularly to an elastic crawler mounted on a crawler-type traveling device of an agricultural machine, a construction machine, or the like. [Background technology]

[0002] Elastic crawlers include protrusion-driven elastic crawlers (see, for example, Patent Document 1 below). This type of elastic crawler includes an endless belt-shaped crawler body, drive protrusions protruding inward from the crawler body, and lugs protruding outward from the crawler body. In this elastic crawler, the driving force of the drive wheels of the traveling device is transmitted to the crawler body and the lugs via the drive lugs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2004-114732 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an elastic crawler that can suppress the occurrence of tooth skipping. [Means for solving the problem]

[0005] The elastic crawler according to the present invention is an elastic crawler comprising an endless belt-shaped crawler body, drive protrusions protruding inward from the crawler body, and lugs protruding outward from the crawler body, and transmits the driving force of a drive wheel of a traveling device to the crawler body and the lugs via the drive protrusions. The elastic crawler comprises an elastic body and a plurality of core metals covered with the elastic body. The plurality of core metals are arranged in the circumferential direction of the elastic crawler. Each of the core metals comprises a base included in the crawler body, an inner protrusion protruding inward from the base, and an outer protrusion protruding outward from the base. The inner protrusion reinforces the drive protrusion. A portion of the outer protrusion is located inside the lug. Effect of the Invention

[0006] The elastic crawler of the present invention can suppress the occurrence of tooth skipping. In this elastic crawler, the driving force of the drive wheels of the traveling device is effectively transmitted to the crawler body and the lugs via the drive lugs. This elastic crawler can contribute to improving the performance of the traveling device. [Brief description of the drawings]

[0007] [Figure 1] 2 is a plan view showing a portion of the elastic crawler according to the embodiment of the present invention. FIG. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. [Figure 4] 2 is a side view showing a part of the elastic crawler of FIG. 1. [Diagram 5] 13 is a cross-sectional view showing a modified example of the outer protrusion. FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. [Figure 7] FIG. 2 is a side view showing an example of a crawler-type traveling device. [Figure 8] 8 is a side view showing a part of the traveling device shown in FIG. 7. [Figure 9]1 is a side view showing a portion of a conventional elastic crawler, and FIG 2 is a side view showing a portion of a conventional elastic crawler. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Foundations underlying the present invention] Fig. 7 shows an example of a crawler type traveling device 2. Fig. 8 shows a part of the traveling device 2 shown in Fig. 7. The traveling device 2 includes an elastic crawler 4, a sprocket 6, an idler 8, and a roller 10.

[0009] The elastic crawler 4 is a protrusion-driven elastic crawler. The elastic crawler 4 is in the form of an endless belt. The elastic crawler 4 is wound around a sprocket 6, an idler 8, and a roller 10. The elastic crawler 4 comprises a crawler body 12 , a drive lug 14 projecting inwardly from the crawler body 12 , and a lug 16 projecting outwardly from the crawler body 12 .

[0010] The sprocket 6 is a drive wheel. Driving means (not shown) rotate the sprocket 6, for example in the direction indicated by the arrow R.

[0011] The sprocket 6 of the traveling device 2 includes a drive pin 18. When the sprocket 6 rotates, the drive pin 18 moves in the rotation direction R of the sprocket 6. The moving drive pin 18 eventually comes into contact with the drive lug 14. While maintaining its contact with the drive lug 14, the drive pin 18 moves the drive lug 14 in the rotational direction R of the sprocket 6. The crawler body 12 moves in the direction indicated by arrow A, and the lugs 16 come into contact with the road surface. The lugs 16 graze the road surface, causing the traveling device 2 to travel. In this traveling device 2, the driving force of a sprocket 6 serving as a driving wheel is transmitted to the crawler body 12 and the lugs 16 via the driving lugs 14.

[0012] 9 shows a part of the elastic crawler 4. In FIG. 9, the dashed dotted line DL is the circumferential center line of the driving lug 14. The elastic crawler 4 includes a core metal 20. The core metal 20 is covered with an elastic body 22. The core metal 20 reinforces the driving lug 14. A portion of the core metal 20 is included in the crawler body 12, but is not included in the lug 16. The core metal 20 is disposed away from the lug 16 and inward.

[0013] A force is applied to the drive lug 14 by the drive pin 18. This generates a force moment having a center of rotation between the core metal 20 and the lug 16 (specifically, at the position indicated by the symbol RC on the circumferential center line DL of the drive lug 14). If the force acting on the drive lug 14 is large, the drive lug 14 may fall in the direction indicated by the arrow F, causing the drive pin 18 to come off from the drive lug 14. The coming off of the drive pin 18 from the drive lug 14 is also called "tooth skipping." When tooth skipping occurs, the traveling device 2 cannot adequately transmit the driving force of the sprocket 6 to the crawler body 12. Tooth skipping reduces the efficiency of transmission of the driving force. Although it is possible to prevent the driving projections 14 from falling over by increasing the circumferential length of the core 20 (ie, the width of the core 20), in this case there is a risk that the flexibility of the elastic crawler will decrease.

[0014] The inventors conducted extensive research into the mechanism by which drive protrusion 14 falls in order to prevent tooth skipping, and discovered that the core bar 20 is involved in the falling of drive protrusion 14. In other words, because the core bar 20 is positioned as a whole on the side of drive protrusion 14, drive protrusion 14 is unable to resist the moment of force with position RC as the center of rotation, and so rotates. This led to the completion of the invention described below.

[0015] [Overview of the embodiment of the present invention] [Configuration 1] An elastic crawler according to one embodiment of the present invention comprises an endless belt-shaped crawler body, a drive protrusion protruding inward from the crawler body, and a lug protruding outward from the crawler body, and transmits the driving force of a drive wheel of a running device to the crawler body and the lug via the drive protrusion, the elastic crawler comprising an elastic body and a plurality of core wires covered by the elastic body, the plurality of core wires being arranged in the circumferential direction of the elastic crawler, each core wire comprising a base included in the crawler body, an inner protrusion protruding inward from the base, and an outer protrusion protruding outward from the base, the inner protrusion reinforcing the drive protrusion, and a portion of the outer protrusion being located inside the lug.

[0016] By arranging the elastic crawler in this manner, the occurrence of tooth skipping can be suppressed.

[0017] [Configuration 2] Preferably, in the elastic crawler according to the above-mentioned [Configuration 1], the ratio of the height of the outer protrusion located inside the lug to the height of the lug is 1 / 3 or less.

[0018] [Configuration 3] Preferably, in the elastic crawler described in the above-mentioned [Configuration 1] or [Configuration 2], in a cross-section of the elastic crawler taken along a plane including the circumferential center line of the core, the outer protrusion has a trapezoidal or bowl-shaped cross-sectional shape, and in a cross-section of the elastic crawler taken along a plane including the center line of the core in the width direction of the elastic crawler, the outer protrusion has a triangular or rectangular cross-sectional shape.

[0019] [Details of the embodiment of the present invention] Hereinafter, the present invention will be described in detail based on preferred embodiments with appropriate reference to the drawings.

[0020] 1 shows a part of an elastic crawler 32 (hereinafter, referred to as crawler 32) according to one embodiment of the present invention. This crawler 32 is in the form of an endless belt. This crawler 32 is attached to the traveling device 2 described above. There are no particular limitations on the external shape of this crawler 32. For this crawler 32, a general external shape applied to a crawler can be adopted.

[0021] 1, the direction indicated by the double-headed arrow WD is the width direction of the crawler 32. Unless otherwise specified, the "width direction" refers to the width direction of the crawler 32. The dashed dotted line CL is the center line of the crawler 32 in the width direction. In the present invention, the widthwise inner side of the crawler 32 means a direction approaching the widthwise centerline CL of the crawler 32 in the width direction. The widthwise outer side of the crawler 32 means a direction moving away from the widthwise centerline CL of the crawler 32 in the width direction.

[0022] 1 is the circumferential direction of the crawler 32. The circumferential direction of the crawler 32 is both the length direction and the rotation direction of the crawler 32. Unless otherwise specified, the "circumferential direction" refers to the circumferential direction of the crawler 32.

[0023] The direction perpendicular to the paper surface of FIG. 1 is the thickness direction of the crawler 32. The front side of the paper surface of FIG. 1 is the inner side of the crawler 32, and the back side of the paper surface is the outer side of the crawler 32. The inner side in the thickness direction of the crawler 32 means the inner side of the crawler 32. The direction from the outer surface of the crawler 32 facing the inner surface is also called the inward direction. The outer side in the thickness direction of the crawler 32 means the outer surface side of the crawler 32. The direction from the inner surface of the crawler 32 facing the outer surface is also called the outward direction. Unless otherwise specified, the "thickness direction" refers to the thickness direction of the crawler 32.

[0024] Fig. 2 shows a cross section of the crawler 32 taken along line II-II in Fig. 1. Line II-II in Fig. 1 coincides with the circumferential center line of a driving lug, which will be described later. 2 is a thickness direction of the crawler 32. The side indicated by the symbol TDu is the inner surface side of the crawler 32, and the side indicated by the symbol TDs is the outer surface side of the crawler 32. The cross section of the crawler 32 shown in FIG. 2 is a cross section of the crawler 32 taken along a plane perpendicular to the circumferential direction of the crawler 32.

[0025] Fig. 3 shows a part of a cross section of the crawler 32 taken along line III-III in Fig. 2. Line III-III in Fig. 2 coincides with a width-direction center line CL of the crawler 32. The cross section of the crawler 32 shown in Fig. 3 is a cross section of the crawler 32 taken along a plane perpendicular to the width direction of the crawler 32.

[0026] The crawler 32 includes, as forming elements, a crawler body 34, a driving lug 36, and a lug 38. The crawler body 34 extends in the circumferential direction. The crawler body 34 is in the form of an endless band.

[0027] The drive lug 36 protrudes inward from the inner surface of the crawler body 34. The drive lug 36 is long in the circumferential direction of the crawler 32 and short in the width direction of the crawler 32. In FIG. The length of the drive protrusion 36 along the circumferential direction of the crawler 32 is also referred to as the width of the drive protrusion 36. The length of the drive protrusion 36 along the width direction of the crawler 32 is also referred to as the thickness of the drive protrusion 36. The length of the drive protrusion 36 along the thickness direction of the crawler 32 is also referred to as the height of the drive protrusion 36.

[0028] The crawler 32 is a lug-driven elastic crawler. In the crawler 32, the driving force of the sprocket 6 is transmitted to the crawler body 34 and the lugs 38 via the driving lugs 36.

[0029] In this crawler 32, a drive lug pair 40 is formed, which is composed of two drive lugs 36. As shown in Fig. 1, the two drive lugs 36 constituting the drive lug pair 40 are aligned in the width direction of the crawler 32. The two drive lugs 36 constituting the drive lug pair 40 are disposed on either side of the width direction center line CL of the crawler 32. Although not shown, the crawler 32 is provided with a large number of drive lug pairs 40. The large number of drive lug pairs 40 are arranged at intervals in the circumferential direction of the crawler 32.

[0030] The lugs 38 protrude outward from the outer surface of the crawler body 34. The lugs 38 are short in the circumferential direction of the crawler 32 and long in the width direction of the crawler 32. The length of the lug 38 along the circumferential direction of the crawler 32 is also referred to as the width of the lug 38. The length of the lug 38 along the width direction of the crawler 32 is also referred to as the length of the lug 38. The length of the lug 38 along the thickness direction of the crawler 32 is also referred to as the height of the lug 38.

[0031] The lugs 38 contribute to exerting traction on the traveling device 2. Although not shown, the crawler 32 is provided with a large number of lugs 38. The large number of lugs 38 are arranged at intervals in the circumferential direction. In this crawler 32, long lugs 38L and short lugs 38S in the width direction are arranged alternately in the circumferential direction.

[0032] 3, the drive lug 36 is located inside in the thickness direction of the lug 38. The lug 38 overlaps with the drive lug 36 in the thickness direction of the crawler 32. In this crawler 32, the circumferential center position of the lug 38 coincides with the circumferential center position of the drive lug 36. In Figure 3, the dashed dotted line LL is the circumferential center line of the lug 38. The above-mentioned circumferential center line DL of the drive lug 36 is also the circumferential center line LL of the lug 38. The above-mentioned line II-II is also the circumferential center line LL of the lug 38 and the circumferential center line DL of the drive lug 36.

[0033] The crawler 32 includes an elastic body 42, a core metal 44, and a tension body 46. The elastic body 42, the core metal 44, and the tension body 46 are components of the crawler 32. The elastic body 42 is made of crosslinked rubber. Although not described in detail, the elastic body 42 is made of a rubber composition that is generally used as an elastic body for a crawler. The elastic body 42 covers the core metal 44 and the tension member 46. The surface of the crawler 32 is almost entirely made of the elastic body 42.

[0034] The core metal 44 is embedded in the elastic body 42. The core metal 44 is made of metal. The material of the core metal 44 is steel. The core metal 44 is plate-shaped. The core metal 44 is short in the circumferential direction of the crawler 32 and long in the width direction of the crawler 32. The length of the core bar 44 along the circumferential direction of the crawler 32 is also referred to as the width of the core bar 44. The length of the core bar 44 along the width direction of the crawler 32 is also referred to as the length of the core bar 44. 3, the dashed dotted line ML is the circumferential center line of the core metal 44. In this crawler 32, the circumferential center line ML of the core metal 44 coincides with the circumferential center line DL of the drive lug . 2, the dashed dotted line SL is the widthwise centerline of the core 44. The widthwise centerline SL of the core 44 is the centerline of the core 44 in the width direction of the crawler 32. In this crawler 32, the widthwise centerline SL of the core 44 coincides with the widthwise centerline CL of the crawler 32.

[0035] The core 44 includes a base 48 , wings 50 , an inner projection 52 and an outer projection 54 . The base portion 48 is located at the center in the width direction of the crawler 32. As shown in FIG. The core bar 44 has a pair of wings 50. Each wing 50 extends outward in the width direction from the base 48. The core metal 44 has a pair of inner protrusions 52. The pair of inner protrusions 52 are disposed on either side of the center line CL in the width direction of the crawler 32. Each of the inner protrusions 52 protrudes inward from the base portion 48. The outer projection 54 projects outward from the base 48. The widthwise centerline CL of the crawler 32 intersects with the outer projection 54.

[0036] The crawler 32 includes a plurality of core metals 44. The plurality of core metals 44 are arranged at intervals in the circumferential direction of the crawler 32. The plurality of core metals 44 are lined up in the circumferential direction of the crawler 32.

[0037] The tension body 46 is located outside the core metal 44 in the thickness direction of the crawler 32. In detail, the tension body 46 is located outside the wing portion 50 in the thickness direction. As described above, the core metal 44 has a pair of wing portions 50. As shown in Fig. 2, a tension body 46 is provided on the outer side in the thickness direction of each wing portion 50. This crawler 32 has a pair of tension bodies 46. Each of the pair of tension bodies 46, together with the core metal 44, is covered with an elastic body 42.

[0038] The tension body 46 extends in the circumferential direction. The tension body 46 is in the form of an endless belt. Although not shown, the tension body 46 includes a steel cord. In this crawler 32, a steel cord that is generally used in elastic crawlers is used as the steel cord. In the tension body 46, the steel cord extends substantially in the circumferential direction. The angle that the steel cord makes with the circumferential direction is 5° or less.

[0039] The crawler 32 includes a plurality of core metals 44 arranged in the circumferential direction, and each core metal 44 includes a base portion 48, an inner protrusion 52, and an outer protrusion 54. The base 48 is included in the crawler body 34. The inner lug 52 is included in the drive lug 36. The inner lug 52 reinforces the drive lug 36.

[0040] 3, the two-dot chain line BL is an imaginary line representing the position of the outer surface of the crawler body 34. This imaginary line BL is a line (specifically, a straight line) that connects between the outer surface of one crawler body 34 and the outer surface of the other crawler body 34 that are located on both sides of the lug 38 in the circumferential direction of the crawler 32. As shown in FIG. 3, the imaginary line BL intersects with the outer protrusion 54. 3 is the top of the outer projection 54. The top PT of the outer projection 54 is located outside the imaginary line BL in the thickness direction of the crawler 32. The outer projection 54 protrudes from the outer surface of the crawler body 34. A portion of the outer projection 54 is located inside the lug 38.

[0041] In the present invention, whether or not a portion of the outer projection 54 is located inside the lug 38 is determined in the cross section shown in FIG. 3, that is, along a plane including the center line CL in the width direction of the crawler.

[0042] FIG. 4 shows how the crawler 32 is moved by the drive pin 18 moving in the rotational direction R of the sprocket 6. Similar to the drive lug 14 of the crawler 4 shown in FIG. 9, a force is also applied to the drive lug 36 of this crawler 32 by the drive pin 18. This generates a force moment having a center of rotation between the core 44 and the lug 38, specifically at a position indicated by the symbol RC on the circumferential centerline DL of the drive lug 36. As shown in FIG. 4, this position RC corresponds to the intersection of the circumferential centerline DL of the drive lug 36 and the tension body 46. Although the tension body is not shown in FIG. 9, the position RC shown in FIG. 9 also corresponds to the intersection of the circumferential centerline DL of the drive lug 14 and the tension body.

[0043] In the conventional crawler 4, as shown in Fig. 9, the core metal 20 is located as a whole on the drive lug 14 side. In other words, the entire core metal 20 is located on the inner side in the thickness direction from the rotation center position RC of the force moment. Therefore, in this crawler 4, the drive lug 14 cannot resist the force moment acting on the drive lug 14, and there have been cases where the drive lug 14 has fallen over. In contrast, in this crawler 32, the apex PT of the outer projection 54 is located outward in the thickness direction from the rotation center position RC of the force moment. The outer projection 54 protrudes outward in the thickness direction from the rotation center position RC. As described above, a portion of the outer projection 54 is located inside the lug 38. In this crawler 32, the drive projection 36 acts to resist the force moment generated in the drive projection 36. In this crawler 32, the drive projection 36 is less likely to tip over.

[0044] This crawler 32 can suppress the occurrence of tooth skipping. In this crawler 32, the driving force of the sprocket 6 serving as a driving wheel of the traveling device 2 is effectively transmitted to the crawler body 34 and the lugs 38 via the driving lugs 36. Furthermore, since a part of the core metal 44 is included inside the lugs 38, this crawler 32 can increase the rigidity of the lugs 38. The lugs 38 can contribute to improving traction performance. In this crawler 32, it is not necessary to employ a wide core metal in order to suppress the collapse of the driving lugs 36. This crawler 32 can maintain good flexibility. This crawler 32 can contribute to improving the performance of the traveling device 2.

[0045] 3, the length indicated by the double arrow HL is the distance in the thickness direction from the inner surface of the crawler body 34 to the top of the lug 38. This distance HL is the height of the lug 38. The length indicated by the double arrow HP is the distance in the thickness direction from the inner surface of the crawler body 34 to the top PT of the outer projection 54 of the core metal 44. This distance HP is the height of the outer projection 54 located inside the lug 38.

[0046] The lugs 38 wear down as the lugs travel. As the wear progresses, the core metal 44 eventually becomes exposed. As the height of the outer projections 54 increases, the core metal 44 can more effectively suppress the driving projections 36 from falling over, but the timing at which the core metal 44 becomes exposed increases. In this crawler 32, the ratio (HP / HL) of the height HP of the outer protrusions 54 located inside the lugs 38 to the height HL of the lugs 38 is preferably 1 / 3 or less. This allows the crawler 32 to control the timing of exposure of the core metal 44 so that the core metal 44 becomes exposed after the lugs 38 have worn down to a certain extent. The crawler 32 can effectively control the timing of exposure of the core metal 44 due to wear and suppress the occurrence of tooth skipping. From the viewpoint of enabling the core metal 44 to contribute to suppressing the falling of the driving projection 36, the ratio (HP / HL) is preferably 1 / 12 or greater.

[0047] As described above, Fig. 2 shows a cross section of the crawler 32 taken along a plane perpendicular to the circumferential direction of the crawler 32. The cross section of the crawler 32 shown in Fig. 2 is a cross section of the crawler 32 taken along a plane including the circumferential center line ML of the core metal 44. This cross section extends in the thickness direction of the crawler 32 and in its width direction.

[0048] 2 is the widthwise outer end of the boundary portion between the outer protrusion 54 and the base portion 48. This widthwise outer end PB is represented by the base of the outer protrusion 54, that is, the intersection point between the side surface of the outer protrusion 54 and the outer surface of the wing portion 50. In this crawler 32, the widthwise outer end PB of the boundary portion is also the widthwise outer end of the outer protrusion 54. 2 is the widthwise inner end of the boundary portion between the drive lugs 36 and the crawler body 34. This widthwise inner end PU is represented by the widthwise inner root of the drive lugs 36, i.e., the intersection between the widthwise inner side surface of the drive lugs 36 and the inner surface of the crawler body 34 between the two drive lugs 36. In this crawler 32, the widthwise inner end PU of the boundary portion is also the widthwise inner end of the drive lugs 36. 2 is the widthwise outer end of the boundary portion between the drive protrusion 36 and the crawler body 34. This widthwise outer end PS is represented by the widthwise outer base of the drive protrusion 36, in other words, the intersection point between the widthwise outer side surface of the drive protrusion 36 and the inner surface of the crawler body 34 that protrudes widthwise outward from the drive protrusion 36. In this crawler 32, the widthwise outer end PS of the boundary portion is also the widthwise outer end of the drive protrusion 36.

[0049] The longer the widthwise length of the outer protrusion 54, i.e., the longer the length of the outer protrusion 54, the more it can contribute to suppressing the occurrence of the above-mentioned tooth skipping. From this viewpoint, it is preferable that the widthwise outer end PB of the boundary portion between the outer protrusion 54 and the base portion 48 is located widthwise outboard of the widthwise inner end PU of the boundary portion between the drive protrusion 36 and the crawler body 34. An outer protrusion 54 that is too long increases the mass of the crawler 32. From the viewpoint of suppressing the effect of the core metal 44 on the mass, it is preferable that the widthwise outer end PB of the boundary portion between the outer protrusion 54 and the base portion 48 is located widthwise inward of the widthwise outer end PS of the boundary portion between the drive protrusion 36 and the crawler body 34.

[0050] In the cross section shown in Fig. 2, the outer protrusions 54 taper outward. This outer protrusion 54 is lighter than a cross-sectional shape that is rectangular. The core bar 44 having this outer protrusion 54 can contribute to suppressing the occurrence of tooth skipping while suppressing the impact on the mass of the crawler 32. From this viewpoint, it is preferable that the outer protrusions 54 taper outward in the cross section of the crawler 32 taken along a plane including the circumferential center line ML of the core bar 44. The outer protrusion 54 shown in Fig. 2 has a trapezoidal cross-sectional shape. This outer protrusion 54 may have a triangular cross-sectional shape, but in this case, the reaction force of the outer protrusion 54 may be insufficient, and the drive protrusion 36 may not be able to fully resist the force moment generated in the drive protrusion 36. From the viewpoint that the outer protrusion 54 can effectively contribute to suppressing the occurrence of tooth skipping, it is preferable that the outer protrusion 54 has a trapezoidal cross-sectional shape.

[0051] Fig. 5 shows a modified example of outer protrusions 54 provided on core bar 44. Fig. 5 shows crawler 62 having a similar configuration except that the shape of outer protrusions 54 of crawler 32 is changed. Therefore, in Fig. 5, elements that are the same as those of crawler 32 are given the same reference numerals and descriptions thereof are omitted.

[0052] FIG. 5 shows a cross section of the crawler 62 taken along a plane including the circumferential centerline ML of the core bar 44 . 5, the outer protrusion 54 of the crawler 62 has a bowl-shaped cross-sectional shape in a cross section taken along a plane including the circumferential center line ML of the core metal 44. Like the outer protrusion 54 having a trapezoidal cross-sectional shape described above, the outer protrusion 54 having a bowl-shaped cross-sectional shape can also contribute to suppressing the occurrence of tooth skipping while suppressing the impact on the mass of the crawler 32. From this perspective, it is preferable that the outer protrusion 54 has a trapezoidal or bowl-shaped cross-sectional shape in a cross section taken along a plane including the circumferential center line ML of the core metal 44.

[0053] As described above, Fig. 3 shows a cross section of the crawler 32 taken along a plane perpendicular to the width direction of the crawler 32. The cross section of the crawler 32 shown in Fig. 3 is a cross section of the crawler 32 taken along a plane including the width direction center line SL of the core metal 44. This cross section extends in the thickness direction of the crawler 32 and in the circumferential direction thereof.

[0054] As shown in FIG. 3, in a cross section taken along a plane including the widthwise center line SL of the core metal 44, the length of the outer protrusion 54 along the circumferential direction (hereinafter also referred to as the width of the outer protrusion 54) is shorter than the length of the base 48 along the circumferential direction (hereinafter also referred to as the width of the base 48). In other words, in the cross section shown in FIG. 3, the width of the outer protrusion 54 is narrower than the width of the base 48. The outer protrusion 54 can contribute to suppressing the occurrence of tooth skipping while suppressing the effect on the mass of the crawler 32. From this viewpoint, in a cross section taken along a plane including the widthwise center line SL of the core metal 44, it is preferable that the width of the outer protrusion 54 is narrower than the width of the base 48, in other words, the outer protrusion 54 has a circumferential length shorter than the circumferential length of the base 48.

[0055] The outer protrusion 54 shown in Fig. 3 has a triangular cross-sectional shape. The cross-sectional shape of this outer protrusion 54 tapers outward. The outer protrusion 54 having this cross-sectional shape can contribute to suppressing the occurrence of tooth skipping while suppressing the impact on the mass of the crawler 32. From this viewpoint, it is preferable that the outer protrusion 54 has a triangular cross-sectional shape in a cross section along a plane including the width direction center line SL of the core bar 44.

[0056] Fig. 6 is a cross section taken along line VI-VI in Fig. 5. This cross section is a cross section of the crawler 62 taken along a plane including the center line SL of the core bar 44 in the width direction.

[0057] 6 has a rectangular cross-sectional shape in a cross section taken along a plane including the widthwise center line SL of the core bar 44. The width of the outer protrusion 54 is narrower than the width of the base 48. Therefore, even if a rectangular cross-sectional shape is adopted for the outer protrusion 54, this outer protrusion 54 can contribute to suppressing the occurrence of tooth skipping while suppressing the impact on the mass of the crawler 32. From this viewpoint, it is preferable that the outer protrusion 54 has a triangular or rectangular cross-sectional shape in a cross section taken along a plane including the widthwise center line SL of the core bar 44.

[0058] As described above, in a cross section taken along a plane including the circumferential centerline ML of the core bar 44, the outer projection 54 preferably has a trapezoidal or bowl-shaped cross-sectional shape. From the standpoint of being able to suppress the occurrence of tooth skipping while minimizing the impact on the mass of the crawler 32, it is more preferable that the outer protrusion 54 has a trapezoidal or bowl-shaped cross-sectional shape in a cross-section along a plane including the circumferential centerline ML of the core wire 44, and that the outer protrusion 54 has a triangular or rectangular cross-sectional shape in a cross-section along a plane including the widthwise centerline SL of the core wire 44.

[0059] As shown in Fig. 6, when the outer protrusion 54 has a rectangular cross-sectional shape, the drive protrusion 36 can more sufficiently resist the force moment generated in the drive protrusion 36, so that the occurrence of tooth skipping is effectively suppressed. On the other hand, as shown in Fig. 3, when the outer protrusion 54 has a triangular cross-sectional shape, the outer protrusion 54 can contribute to weight reduction. Therefore, when emphasis is placed on suppressing tooth skipping, it is preferable that the outer protrusion 54 has a rectangular cross-sectional shape in a cross section along a plane including the widthwise center line SL of the core bar 44. When emphasis is placed on the effect on mass, it is preferable that the outer protrusion 54 has a triangular cross-sectional shape in this cross section.

[0060] As is clear from the above description, according to the present invention, an elastic crawler capable of suppressing the occurrence of tooth skipping can be obtained. [Industrial Applicability]

[0061] The above-described technology capable of suppressing the occurrence of tooth skipping can be applied to various elastic crawlers. [Explanation of symbols]

[0062] 2. Travelling gear 4, 32, 62... Elastic crawler 6···Sprocket 8. Idler 10. Roller 12, 34... Crawler body 14, 36... Drive protrusion 16, 38, 38L, 38S... Lugs 18 Drive pin 20, 44...Core 22, 42... Elastic body 40... Drive lug pair 46...tensile body 48...Base 50...wing section 52...medial protrusion 54...lateral process

Claims

1. An elastic crawler including an endless belt-shaped crawler body, a drive protrusion protruding inward from the crawler body, and a lug protruding outward from the crawler body, the elastic crawler transmitting a driving force of a drive wheel of a traveling device to the crawler body and the lug via the drive protrusion, The present invention includes an elastic body and a plurality of core metals covered with the elastic body, A plurality of the core metals are arranged in a circumferential direction of the elastic crawler, Each of the core metals includes a base portion included in the crawler body, an inner protrusion protruding inward from the base portion, and an outer protrusion protruding outward from the base portion, the inner protrusion reinforces the drive protrusion; A portion of the outer projection is located within the lug. Elastic crawler.

2. The ratio of the height of the outer protrusion located inside the lug to the height of the lug is 1 / 3 or less. The elastic crawler according to claim 1 .

3. In a cross section of the elastic crawler taken along a plane including a circumferential center line of the core metal, the outer protrusion has a trapezoidal or bowl-shaped cross-sectional shape, In a cross section of the elastic crawler taken along a plane including a center line of the core bar in a width direction of the elastic crawler, the outer protrusion has a triangular or rectangular cross-sectional shape. The elastic crawler according to claim 1 or 2.

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