Elastic Track

Abstract

The present invention provides an elastic crawler (30) which can ensure the rigidity and wear resistance of a guide protrusion (6) and achieve lightweight, thereby helping to improve the resistance to unseating. The elastic crawler (30) includes: a crawler body (60); and a guide protrusion (64) protruding from a wheel passing surface (70) of the crawler body (60). The crawler body (60) includes a tension body (42). The guide protrusion (64) includes a core (40). The tension body (42) and the core (40) are covered by an elastic component (38). The maximum width WC of the core (40) is smaller than the maximum width WR of the guide protrusion (64). The guide protrusion (64) includes a pair of outer side surfaces (76) located on the outside in the width direction. Each outer side surface (76) includes a first core reflection area (90) having a shape along the shape of the core (40) at a portion thereof.

Description

Technical Field

[0001] The present invention relates to an elastic crawler, and more particularly to an elastic crawler mounted on a traveling device such as an agricultural machine or a construction machine. Background Art

[0002] Crawler-type travel devices such as agricultural machines such as combine harvesters and tractors and construction machines such as backhoes include endless elastic crawlers. Patent Document 1 below discloses an example of an elastic crawler.

[0003] exist Figure 5 2 shows a cross section of a conventional elastic crawler 2. The elastic crawler 2 includes a crawler body 4, guide protrusions 6 protruding inward from the crawler body 4, and projections 8 protruding outward from the crawler body 4.

[0004] In the travel device, the guide protrusion 6 is meshed with the sprocket. The sprocket rotates and moves the guide protrusion 6. The elastic crawler 2 moves in the circumferential direction, and the travel device travels. From the viewpoint of driving force transmission, the guide protrusion 6 is configured to have high rigidity.

[0005] In order to ensure rigidity, the guide protrusion 6 includes a metal core 10. The tension member 12 is located outside the core 10. The core 10 and the tension member 12 are usually covered with an elastic member 14 such as cross-linked rubber. Figure 5 As shown, the outer side surface 16 of the guide protrusion 6 has a shape along the core 10 as a whole. In this elastic crawler 2, the shape of the core 10 is reflected on the outer side surface 16 of the guide protrusion 6 as a whole.

[0006] Patent Document 1: Japanese Patent Application Publication No. 2005-271711

[0007] If the guide protrusion is formed only of elastic components, a light elastic crawler can be obtained. The elastic crawler improves the fuel consumption performance of the travel device. On the other hand, the travel device is being driven to have a higher driving force. Forming the guide protrusion only of elastic components is disadvantageous in terms of rigidity and wear resistance.

[0008] In the case where the guide protrusion is composed only of an elastic component, if the rigidity and wear resistance cannot be sufficiently ensured, it may cause unbending. In order to prevent unbending, it has been studied to constitute a pair of flanges arranged in parallel in the width direction as a guide protrusion. In terms of ensuring the rigidity of the guide protrusion, it is difficult to obtain a guide protrusion having a pair of flanges without using a core. In order to achieve the exertion of driving force and improve the resistance to unbending, the use of a core is indispensable. Although the guide protrusion includes a core, it is required to establish a technology that can achieve lightweighting. Summary of the invention

[0009] The present invention has been made in view of such actual circumstances, and an object of the present invention is to provide an elastic crawler that can ensure the rigidity and wear resistance of the guide protrusions and achieve weight reduction.

[0010] An elastic crawler according to one embodiment of the present invention comprises: an endless crawler body; and a guide protrusion protruding from a runner passing surface formed on the inner circumferential surface of the crawler body. The crawler body includes a tension body extending in the circumferential direction. The guide protrusion includes a core. The tension body and the core are covered by an elastic member. The maximum width of the core is smaller than the maximum width of the guide protrusion. The guide protrusion includes a pair of outer side surfaces located on the outside in the width direction. Each outer side surface includes, in a portion thereof, a first core reflection area having a shape along the shape of the core.

[0011] Preferably, in the elastic crawler, the core is exposed in the first core reflection region.

[0012] Preferably, in the elastic crawler, a ratio of an area of ​​the first core reflection region to an area of ​​the outer surface is 10% or less.

[0013] Preferably, in the elastic crawler, a ratio of a height from the running wheel passing surface to the first core reflection region to a height of the guide protrusion is 20% or more and less than 50%.

[0014] Preferably, in the elastic crawler, the guide protrusion includes a groove that is recessed outward from a top surface, and a groove wall of the groove includes a second core reflection region having a shape along the shape of the core in a portion thereof.

[0015] Preferably, in the elastic crawler, the core is exposed in the second core reflection region.

[0016] Preferably, in the elastic crawler, a ratio of an area of ​​the second core reflection region to an area of ​​the groove wall is 10% or less.

[0017] Preferably, in the elastic crawler, a ratio of a height from a groove bottom of the groove to the second core reflection region to a depth of the groove is 60% or more and 90% or less.

[0018] Preferably, in the elastic crawler, the bottom of the core is located outside the running wheel passing surface.

[0019] Preferably, in the elastic crawler, the crawler body includes a reinforcement layer on an outer side of the tension body, and the reinforcement layer extends in a circumferential direction.

[0020] Preferably, in the elastic crawler, a position where the core shows a maximum width is located between a top and a bottom of the core.

[0021] Preferably, in the elastic crawler, a position where the core shows a maximum width is included in the first core reflection region.

[0022] Preferably, in the elastic crawler, the core is made of metal.

[0023] According to the present invention, it is possible to obtain an elastic crawler which can ensure the rigidity and wear resistance of the guide protrusions and achieve weight reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a side view showing an example of a travel device to which an elastic crawler belt according to an embodiment of the present invention is mounted.

[0025] Figure 2 is a side view showing a portion of the elastic track.

[0026] Figure 3 is along Figure 2 Cross-sectional view taken along line III-III.

[0027] Figure 4 is along Figure 3 Cross-sectional view taken along line IV-IV.

[0028] Figure 5 This is a cross-sectional view showing a part of a conventional elastic crawler.

[0029] Description of Reference Numerals

[0030] 2, 30…elastic crawler track; 4, 60…track body; 6, 64…guide protrusion; 8, 62…bump; 10, 40…core body; 12, 38…elastic component; 14, 76…outer side surface; 22…traveling device; 24…sprocket; 28…rotor; 42…tension body; 44…reinforcement layer; 46…base; 48…rising portion; 50…plate portion; 52…protrusion; 54…top of core body 40; 56…bottom of core body 40; 70…rotor passing surface; 72…top surface; 86…groove; 88…flange portion; 90…first core body reflection area; 92…groove wall; 96…second core body reflection area. DETAILED DESCRIPTION

[0031] Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings as appropriate.

[0032] [Driving device]

[0033] Figure 1 2 is an example of a crawler type travel device 22. The travel device 22 includes a sprocket 24, an idler wheel 26, a running wheel 28, and an elastic crawler belt 30.

[0034] The sprocket 24 is located in front of the travel device 22. The sprocket 24 is disc-shaped. The sprocket 24 has a plurality of teeth 32 on its outer periphery. The sprocket 24 is rotatably supported by the machine body 34. Although not shown, the machine body 34 has a drive unit such as a prime mover built in. The drive unit rotates the sprocket 24.

[0035] The idler wheel 26 is located on the rear side of the travel device 22. The idler wheel 26 is disc-shaped and is rotatably supported by the machine body 34.

[0036] The rotating wheel 28 is located between the sprocket 24 and the idler wheel 26. The rotating wheel 28 is rotatably supported by the machine body 34. In the travel device 22, a plurality of rotating wheels 28 are arranged at intervals.

[0037] The elastic crawler belt 30 is an endless belt and is wound around the sprocket 24 , the idler wheel 26 , and the running wheel 28 .

[0038] Although not described in detail, in the travel device 22, when the sprocket 24 rotates, the elastic crawler 30 moves in the circumferential direction, and the idler wheel 26 rotates. Thus, the travel device 22 travels. The running wheel 28 rotates on the elastic crawler 30 on the road surface side.

[0039] [Elastic Track 30]

[0040] exist Figure 2 In Figure 1 A portion of the elastic track 30 is shown. Figure 2 In FIG. 1 , the left-right direction is the circumferential direction of the elastic crawler 30. The circumferential direction of the elastic crawler 30 is also the length direction of the elastic crawler 30. Figure 2 In the figure, the up-down direction is the thickness direction of the elastic crawler 30. Figure 1 As shown, the elastic track 30 forms a ring. Figure 2 In the figure, the upper side is the inner side of the ring (hereinafter, also referred to as the inner side), and the lower side is the outer side of the ring (hereinafter, also referred to as the outer side). The direction perpendicular to the paper is the width direction of the elastic crawler 30. Therefore, the left side of the paper is the front side of the travel device 22, and the right side is the rear side of the travel device. When the travel device is moving forward, Figure 2 The elastic track 30 is shown moving from left to right.

[0041] Figure 3 Shown along Figure 2 The cross section of the elastic crawler 30 is cut along the line III-III. Figure 3 , a cross section of the elastic crawler 30 cut along a plane perpendicular to the circumferential direction of the elastic crawler 30 is shown. Figure 3In the figure, the left-right direction is the width direction of the elastic crawler 30. The upper side is the inner side of the ring, and the lower side is the outer side of the ring. The direction perpendicular to the paper surface is the circumferential direction of the elastic crawler 30. The dot-dash line CL is the center line of the elastic crawler 30 in the width direction. Figure 2 The III-III line is the circumferential center line of the core body described later.

[0042] The elastic crawler 30 includes an elastic member 38 , a core 40 , a tension member 42 , and a reinforcing layer 44 as components.

[0043] The elastic member 38 is made of cross-linked rubber. Although not described in detail, in the elastic crawler 30, a commonly used rubber composition for cross-linked rubber is used as the cross-linked rubber of the elastic member 38 to constitute the elastic member 38. The elastic member 38 covers the core 40, the tension member 42, and the reinforcing layer 44. The outer surface of the elastic crawler 30 is almost entirely made of the elastic member 38.

[0044] The core 40 is made of metal. Examples of the material of the core 40 include ordinary steel and alloy steel. The core 40 may also be made of resin. In this case, the material of the core 40 is selected in consideration of the vulcanization temperature set in the manufacture of the elastic crawler 30, for example, a thermoplastic resin having a melting point higher than the vulcanization temperature. From the viewpoint of ensuring the rigidity and wear resistance of the guide protrusion described later, the core 40 is preferably made of metal.

[0045] The core 40 includes a base 46 extending in the width direction and a pair of rising portions 48 extending inward from the ends of the base 46. Each rising portion 48 includes a plate 50 and a protrusion 52 protruding outward from the plate 50 in the width direction.

[0046] exist Figure 3 In FIG. 1 , the double arrow WC indicates the maximum width of the core 40. The core 40 shows the maximum width WC at the protrusion 52. The protrusion 52 is located between the top 54 and the bottom 56 of the core 10. The width of the core 40 is narrow at the top 54 and the bottom 56, and wide at the protrusion 52. Figure 3 In the figure, the reference numeral PC indicates the position where the core 40 shows the maximum width. The maximum width position PC is also the top of the protrusion 52. The position where the core 40 shows the maximum width is located between the top 54 and the bottom 56 of the core.

[0047] The elastic crawler 30 includes a plurality of cores 40. The cores 40 are arranged at intervals in the circumferential direction.

[0048] The tensile body 42 extends in the circumferential direction. The tensile body 42 is in the shape of an annular belt. The tensile body 42 is located outside the core body 40. Although not shown in the figure, the tensile body 42 includes a steel cord. In the tensile body 42, the steel cord substantially extends in the circumferential direction. "Substantially in the circumferential direction" means that the angle formed by the steel cord relative to the circumferential direction is less than 5°.

[0049] The reinforcing layer 44 extends in the circumferential direction. The reinforcing layer 44 is in the shape of an endless belt. The reinforcing layer 44 is located outside the tension body 42. The reinforcing layer 44 includes at least one cord 58. Figure 3 The reinforcement layer 44 shown is composed of two cords 58. Although not shown, each cord 58 includes a plurality of steel cords arranged in parallel. These steel cords are inclined relative to the circumferential direction. In the elastic crawler 30, the angle formed by the steel cords included in the cord 58 relative to the circumferential direction is preferably 45° or more, more preferably 50° or more, and further preferably 55° or more. The angle is preferably 75° or less, more preferably 70° or less, and further preferably 65° or less. From the viewpoint of ensuring the rigidity of the reinforcement layer 44, the inclination direction of the steel cords included in another cord 58 stacked on one cord 58 is preferably opposite to the inclination direction of the steel cords included in the cord 58.

[0050] The elastic crawler 30 includes a crawler body 60 , a lug 62 , and a guide protrusion 64 as shape elements.

[0051] The crawler body 60 extends in the circumferential direction. The crawler body 60 is in the shape of an endless belt. The crawler body 60 includes the elastic member 38, the tension body 42, and the reinforcing layer 44. In the crawler body 60, the entire tension body 42 and the reinforcing layer 44 are covered by the elastic member 38.

[0052] The projection 62 is formed of the elastic member 38. The projection 62 projects outward from the outer peripheral surface 66 of the crawler body 60. The projection 62 is long in the width direction and short in the circumferential direction. The projection 62 contributes to the traction of the travel device 22.

[0053] The elastic crawler 30 includes a plurality of protrusions 62. The protrusions 62 are arranged at intervals in the circumferential direction. In the elastic crawler 30, two protrusion rows consisting of a plurality of protrusions 62 arranged in the circumferential direction are formed. The two protrusion rows are arranged side by side in the width direction across the center line CL.

[0054] The guide protrusion 64 protrudes inward from the inner circumferential surface 68 of the crawler body 60. As described above, the runner 28 rotates on the elastic crawler 30. The inner circumferential surface 68 of the crawler body 60 is formed with a runner passing surface 70 for the runner 28 to rotate. In the elastic crawler 30, the runner passing surface 70 is formed on the guide protrusion 64 side of the inner circumferential surface 68 that expands outward in the width direction from the guide protrusion 64. The guide protrusion 64 protrudes from the runner passing surface 70 formed on the inner circumferential surface 68.

[0055] The guide protrusion 64 includes a top surface 72 and four side surfaces 74 extending from the top surface 72 toward the crawler body 60. The side surface 74 located outside in the width direction of the side surfaces 74 is an outer side surface 76. The guide protrusion 64 includes a pair of outer side surfaces 76 located outside in the width direction. Of the two side surfaces 74 spanning the left and right outer side surfaces 76, the side surface 74 located in front in the moving direction of the guide protrusion 64 when the travel device moves forward is a front ground contact side surface 78, and the side surface 74 located in the rear is a rear ground contact side surface 80.

[0056] exist Figure 3 In the figure, reference numeral PR is the root of the guide protrusion 64. The root PR is represented by the position where the wheel passing surface 70 and the outer side surface 76 intersect. Figure 3 In FIG. 1 , the double arrow WR indicates the maximum width of the guide protrusion 64. In the elastic crawler 30, the guide protrusion 64 shows the maximum width WR at the root PR.

[0057] like Figure 3 As shown, the guide protrusion 64 is configured such that the distance between the left and right outer side surfaces 76 gradually decreases from the root PR toward the top surface 72. The outer side surface 76 of the guide protrusion 64 includes a first outer side surface 82 on the root PR side and a second outer side surface 84 on the top surface 72 side. Reference symbol PB represents the boundary between the first outer side surface 82 and the second outer side surface 84.

[0058] like Figure 3 As shown, the inclination angle of the second outer side surface 84 with respect to the thickness direction of the elastic crawler 30 is greater than the inclination angle of the first outer side surface 82 with respect to the thickness direction of the elastic crawler 30. In the elastic crawler 30, it is preferred that the inclination angle of the first outer side surface 82 is set within a range of 5° to 10°, and the inclination angle of the second outer side surface 84 is set within a range of 20° to 40°.

[0059] In the elastic crawler 30 , the guide protrusion 64 includes the core 40 and the elastic member 38 . The guide protrusion 64 includes the core 40 , and the core 40 is covered with the elastic member 38 .

[0060] As described above, the core 40 includes: a base 46 extending in the width direction; and a pair of raised portions 48 extending inward from the ends of the base 46. In other words, the core 40 has a shape in which the center portion in the width direction is concave outward. Figure 3 As shown, the guide protrusion 64 of the elastic crawler 30 can be provided with a groove 86 that is recessed outward from the top surface 72. Thus, a pair of flanges 88 arranged in parallel in the width direction are formed on the guide protrusion 64. The guide protrusion 64 having a pair of flanges 88 helps prevent the elastic crawler 30 from being unhooked.

[0061] The core 40 improves the rigidity and wear resistance of the guide protrusion 64. In addition, the elastic crawler 30 can also form a pair of flanges 88 arranged in parallel in the width direction as described above on the guide protrusion 64. The elastic crawler 30 can be installed in various types of travel devices 22, such as a travel device 22 using a saddle wheel, a travel device 22 using a convex wheel, and a travel device 22 using a double-shoulder wheel. The elastic crawler 30 can also be installed in a travel device 22 having a bead-unseling prevention guide called a boat-shaped guide. The elastic crawler 30 contributes to improving bead-unseling resistance.

[0062] As described above, the width of the core 40 is narrow at the top 54 and the bottom 56 thereof, and is wide at the protrusion 52. Since the core 40 is covered by the elastic member 38, an area having a shape along the shape of the core 40 (specifically, the protrusion 52) is formed on the outer side surface 76 of the guide protrusion 64 (hereinafter referred to as the first core reflection area 90). In the elastic crawler 30, the thickness of the elastic member 38 in the first core reflection area 90 is 0.5 mm or less. In the elastic crawler 30, the area of ​​the outer side surface 76 of the guide protrusion 64, which shows that the thickness of the elastic member 38 is 0.5 mm or less, represented by the distance from the outer side surface 76 to the core 40, is the first core reflection area 90. The first core reflection area 90 includes the position PC where the core 40 shows the maximum width. The thickness of the elastic member 38 being 0.0 mm means that the core 40 is exposed.

[0063] In the elastic crawler 30, the first core reflection area 90 may be composed of an elastic member 38 (hereinafter referred to as a thin skin of the elastic member 38) of 0.5 mm or less that covers the protrusion 52. In the first core reflection area 90, the protrusion 52 of the core 40 may be exposed. In this case, the first core reflection area 90 may be composed of the exposed protrusion 52. It is also possible that a part of the first core reflection area 90 is composed of the exposed protrusion 52, and the other part is composed of the thin skin of the elastic member 38. From the viewpoint of preventing the elastic member 38 from curling up and improving the wear resistance, it is preferred that the first core reflection area 90 is composed of the exposed protrusion 52, i.e., the exposed core 40.

[0064] In the elastic crawler 30, the shape of the first core reflection area 90 is not particularly limited. The shape of the first core reflection area 90 can be a rectangle, a square, a circle, or an ellipse. Figure 2 The shape of the first core reflection area 90 is shown to be rectangular.

[0065] In the elastic crawler 30, the maximum width WC of the core 40 is smaller than the maximum width WR of the guide protrusion 64. The outer side surface 76 of the guide protrusion 64 does not have a shape along the shape of the core 40 as a whole as in the conventional elastic crawler, but a part thereof has a shape along the shape of the core 40. In other words, the outer side surface 76 of the guide protrusion 64 includes a first core reflection area 90 having a shape along the shape of the core 40 in a part thereof. In the elastic crawler 30, the volume of the elastic member 38 located between the outer side surface 76 and the core 40 is larger than the corresponding volume of the conventional elastic crawler 2. Since the proportion of the core 40 occupying the guide protrusion 64 is low, the elastic crawler 30 is lightweight even though the guide protrusion 64 includes the core 40. The lightweight elastic crawler 30 contributes to improving the fuel consumption performance of the travel device 22.

[0066] The structure of the guide protrusion 64 is based on the following new insight obtained by the inventor through detailed investigation of the wear condition of the guide protrusion in the existing elastic track: wear occurs on the side or part of the groove, and if the area where the wear occurs has a shape along the shape of the core, the wear can be prevented without damaging the function of the guide protrusion.

[0067] The elastic crawler 30 can ensure the rigidity and wear resistance of the guide protrusion 6 and achieve lightweight. As mentioned above, the elastic crawler 30 can help improve the anti-separation performance. The elastic crawler 30 can ensure the rigidity and wear resistance of the guide protrusion 64 and achieve lightweight, which helps improve the anti-separation performance.

[0068] As described above, in the elastic crawler 30, the maximum width WC of the core 40 is smaller than the maximum width WR of the guide protrusion 64. From the viewpoint of weight reduction, the ratio (WC / WR) of the maximum width WC of the core 40 to the maximum width WR of the guide protrusion 64 is preferably 98% or less, more preferably 96% or less. From the viewpoint of ensuring rigidity and wear resistance, the ratio (WC / WR) is preferably 90% or more, more preferably 92% or more.

[0069] In the elastic crawler 30, it is preferred that the ratio of the area of ​​the first core reflection region 90 to the area of ​​the outer side surface 76 is 10% or less. As a result, the ratio of the core 40 to the guide protrusion 64 is further reduced. The elastic crawler 30 can be further lightweight. The elastic crawler 30 helps improve the fuel consumption performance of the travel device 22. From this viewpoint, the ratio is more preferably 5% or less. From the viewpoint of ensuring the rigidity and wear resistance of the guide protrusion 64, the ratio is preferably 1% or more, and more preferably 3% or more.

[0070] The area of ​​the outer side surface 76 of the guide protrusion 64 is obtained based on the contour of the outer side surface 76. In the elastic crawler 30, the contour of the outer side surface 76 is represented by the boundary between the top surface 72 and the outer side surface 76, the boundary between the front contact side surface 78 and the outer side surface 76, the boundary between the runner passing surface 70 and the outer side surface 76 (that is, the root PR), and the boundary between the rear contact side surface 80 and the outer side surface 76. In the case where each boundary is rounded, the contour of the outer side surface 76 is determined by the intersection line of the top surface 72 and the outer side surface 76, the intersection line of the front contact side surface 78 and the outer side surface 76, the intersection line of the runner passing surface 70 and the outer side surface 76, and the intersection line of the rear contact side surface 80 and the outer side surface 76. In the elastic crawler 30, the area of ​​the outer side surface 76 is represented by the sum of the area of ​​the first outer side surface 82 and the area of ​​the second outer side surface 84.

[0071] exist Figure 2 , the double arrow HT indicates the distance from the wheel passing surface 70 to the top surface 72 of the guide protrusion 64. The distance HT is the height of the guide protrusion 64. The reference numeral P1 is the position of the first core reflection area 90 closest to the wheel passing surface 70 (hereinafter, the bottom of the first core reflection area 90). The double arrow H1 indicates the distance from the wheel passing surface 70 to the bottom P1 of the first core reflection area 90. The distance H1 is the height from the wheel passing surface 70 to the first core reflection area 90. In addition, in the elastic crawler 30, when the position of the wheel passing surface 70 changes in the thickness direction, the position of the root PR of the guide protrusion 64 is used as the position of the wheel passing surface 70, and the distance based on the wheel passing surface 70 is measured.

[0072] In the elastic crawler 30, the ratio (H1 / HT) of the height H1 from the runner passing surface 70 to the first core reflection area 90 to the height HT of the guide protrusion 64 is preferably 20% or more, preferably less than 50%. As a result, the generation of wear in the outer surface 76 can be suppressed, and the mass and rigidity of the guide protrusion 64 can be balanced. The elastic crawler 30 can ensure the rigidity and wear resistance of the guide protrusion 64 and achieve lightweight, which helps to improve the resistance to unseating. From this viewpoint, the ratio (H1 / HT) is more preferably 22% or more, and more preferably 25% or more. The ratio (H1 / HT) is more preferably 48% or less, and more preferably 45% or less.

[0073] As described above, in the elastic crawler 30, the guide protrusion 64 can be provided with the groove 86 that is recessed outward from the top surface 72, thereby forming a pair of flange portions 88 on the guide protrusion 64. The outer side surface of the flange portion 88 is the outer side surface 76 of the guide protrusion 64, and the inner side surface of the flange portion 88 is the groove wall 92 of the groove 86. The groove bottom 94 of the groove 86 is bridged between the left and right groove walls 92.

[0074] Figure 4 Shown along Figure 3 The cross section of the elastic crawler 30 cut along the IV-IV line. Figure 4 In FIG. 1 , the left-right direction is the circumferential direction of the elastic crawler 30. The up-down direction is the thickness direction of the elastic crawler 30. Figure 4 In the figure, the upper side is the inner side of the ring, and the lower side is the outer side of the ring. The direction perpendicular to the paper is the width direction of the elastic crawler 30. Thus, the left side of the paper is the front side of the travel device 22, and the right side is the rear side of the travel device. Figure 3 The IV-IV line is also the center line CL.

[0075] As described above, in the elastic crawler 30, the guide protrusion 64 includes the core 40, and the core 40 is covered by the elastic member 38. The groove wall 92 of the groove 86 provided in the guide protrusion 64 also forms a region (hereinafter referred to as the second core reflection region 96) having a shape along the shape of the core 40 (specifically, the plate portion 50 of the rising portion 48) in the same manner as the outer side surface 76. In the elastic crawler 30, the thickness of the elastic member 38 in the second core reflection region 96 is 0.5 mm or less. In the elastic crawler 30, the region in the groove wall 92 of the groove 86 provided in the guide protrusion 64, which shows that the thickness of the elastic member 38 is 0.5 mm or less, represented by the distance from the groove wall 92 to the core 40, is the second core reflection region 96.

[0076] In the elastic crawler 30, the entire second core reflection area 96 may be formed by the thin skin of the elastic member 38 covering the plate portion 50. In the second core reflection area 96, the plate portion 50 of the core 40 may be exposed. In this case, the entire second core reflection area 96 may be formed by the exposed plate portion 50. It is also possible to make a part of the second core reflection area 96 be formed by the exposed plate portion 50 and another part be formed by the thin skin of the elastic member 38. From the viewpoint of preventing the elastic member 38 from curling up and improving the wear resistance, it is preferred that the entire second core reflection area 96 be formed by the exposed plate portion 50, that is, the exposed core 40.

[0077] In the elastic crawler 30, the shape of the second core reflection area 96 is not particularly limited. The shape of the second core reflection area 96 can be a rectangle, a square, a circle, or an ellipse. Figure 4 The second core reflecting area 96 is shown to be rectangular in shape.

[0078] In the elastic crawler 30, the groove wall 92 and the groove bottom 94 of the groove 86 do not have a shape that follows the shape of the core 40 as a whole, as in the conventional elastic crawler in which a groove is engraved in the guide protrusion to form a pair of flange portions, but a portion thereof has a shape that follows the shape of the core 40. Specifically, the groove wall 92 of the groove 86 includes a second core reflection area 96 having a shape that follows the shape of the core 40 in a portion thereof. In the elastic crawler 30, the volume of the elastic member 38 located between the groove 86 and the core 40 is larger than the corresponding volume of the conventional elastic crawler. Since the proportion of the core 40 occupying the guide protrusion 64 is low, the elastic crawler 30 is lightweight even though the guide protrusion 64 includes the core 40. The lightweight elastic crawler 30 contributes to improving the fuel consumption performance of the travel device 22. From this viewpoint, it is preferable that the guide protrusion 64 has the groove 86 that is recessed outward from the top surface 72, and the groove wall 92 of the groove 86 includes a second core reflection area 96 having a shape that follows the shape of the core 40 in a portion thereof.

[0079] In the elastic crawler 30, it is preferred that the ratio of the area of ​​the second core reflection region 96 to the area of ​​the groove wall 92 is 10% or less. As a result, the ratio of the core 40 to the guide protrusion 64 is further reduced. The elastic crawler 30 can be further lightweight. The elastic crawler 30 can contribute to improving the fuel consumption performance of the travel device. From this point of view, the ratio is more preferably 5% or less. From the viewpoint of ensuring the rigidity and wear resistance of the guide protrusion 64, the ratio is preferably 1% or more, and more preferably 3% or more.

[0080] The area of ​​the groove wall 92 is obtained based on the contour of the groove wall 92. In the elastic crawler 30, the contour of the groove wall 92 is represented by the boundary between the top surface 72 and the groove wall 92, the boundary between the front ground contact side surface 78 and the groove wall 92, the boundary between the groove bottom 94 and the groove wall 92, and the boundary between the rear ground contact side surface 80 and the groove wall 92. When each boundary is rounded, the contour of the groove wall 92 is determined by the intersection line of the top surface 72 and the groove wall 92, the intersection line of the front ground contact side surface 78 and the groove wall 92, the intersection line of the groove bottom 94 and the groove wall 92, and the intersection line of the rear ground contact side surface 80 and the groove wall 92.

[0081] exist Figure 4 , the double arrow HG indicates the distance from the groove bottom 94 of the groove 86 to the top surface 72 of the guide protrusion 64. The distance HG is the depth of the groove 86. The reference numeral P2 is the position of the second core reflection area 96 closest to the groove bottom 94 (hereinafter, the bottom of the second core reflection area 96). The double arrow H2 indicates the distance from the groove bottom 94 of the groove 86 to the bottom P2 of the second core reflection area 96. The distance H2 is the height from the groove bottom 94 of the groove 86 to the second core reflection area 96.

[0082] In the elastic crawler 30, the ratio (H2 / HG) of the height H2 from the groove bottom 94 of the groove 86 to the second core reflection area 96 relative to the depth HG of the groove 86 is preferably 60% or more, preferably 90% or less. As a result, the generation of wear in the groove wall 92 can be suppressed, and the mass and rigidity of the guide protrusion 64 can be balanced. The elastic crawler 30 can ensure the rigidity and wear resistance of the guide protrusion 64 and achieve lightweight, which helps to improve the resistance to unseating. From this viewpoint, the ratio (H2 / HG) is more preferably 62% or more, and more preferably 65% ​​or more. The ratio (H2 / HT) is more preferably 88% or less, and more preferably 85% or less.

[0083] like Figure 3 As shown, in the elastic crawler 30, the bottom 56 of the core 40 is closer to the tension body 42 than the runner passing surface 70. In other words, the bottom 56 of the core 40 is located at a position on the outside of the runner passing surface 70, in other words, on the road surface side. Even if the runner 28 acts on the guide protrusion 64 in the lateral direction, the elastic crawler 30 bears the force as a whole. The concentration of deformation on the root PR of the guide protrusion 64 is suppressed. In the elastic crawler 30, damage such as cracks is prevented from occurring at the root PR of the guide protrusion 64. In the elastic crawler 30, the action based on the guide protrusion 64 is maintained for a long time. From this viewpoint, in the elastic crawler 30, the bottom 56 of the core 40 is preferably located on the outside of the runner passing surface 70.

[0084] exist Figure 2 In FIG. 5 , a double arrow DC indicates the distance from the runner passing surface 70 to the bottom 56 of the core 40 . The distance DC is the embedding depth of the core 40 .

[0085] In the elastic crawler 30, from the viewpoint of preventing damage to the root PR of the guide protrusion 64, the ratio (DC / HT) of the embedding depth DC of the core 40 to the height HT of the guide protrusion 64 is preferably 8% or more, and more preferably 10% or more. From the viewpoint of ensuring the rigidity and wear resistance of the guide protrusion 64 and achieving lightweighting of the elastic crawler 30, the ratio (DC / HT) is preferably 20% or less, and more preferably 15% or less.

[0086] As described above, the elastic crawler 30 includes the reinforcing layer 44, and the reinforcing layer 44 is located outside the tension body 42. In other words, the crawler body 60 of the elastic crawler 30 includes the reinforcing layer 44 outside the tension body 42. The reinforcing layer 44 effectively compensates for the reduction in rigidity of the elastic crawler 30 caused by using a small core 40. In the elastic crawler 30, it is preferred that the crawler body 60 includes the reinforcing layer 44 outside the tension body 42. In this case, from the viewpoint that the reinforcing layer 44 can effectively compensate for the reduction in rigidity of the elastic crawler 30, as shown in FIG. Figure 3 As shown, the reinforcing layer 44 is more preferably composed of two cords 58 .

[0087] like Figure 3 As shown, in the groove bottom 94 of the groove 86, the core 40 is fully covered by the elastic member 38. In this elastic crawler 30, the elastic member 38 in the groove wall 92 of the groove 86 is thin, but the elastic member 38 in the groove bottom 94 of the groove 86 is quite thick. Since the elastic member 38 occupies a high proportion of the guide protrusion 64, the guide protrusion 64 contributes to the lightweighting of the elastic crawler 30. From this viewpoint, in this elastic crawler 30, when the groove 86 is engraved in the guide protrusion 64 and a pair of flange portions 88 are formed, from the viewpoint of ensuring rigidity and wear resistance and achieving lightweighting, the guide protrusion 64 is preferably configured so that the elastic member 38 in the groove wall 92 of the groove 86 is thin and the elastic member 38 in the groove bottom 94 of the groove 86 is thick.

[0088] exist Figure 4 In FIG. 1 , a double arrow TC indicates the distance from the groove bottom 94 of the groove 86 to the base 46 of the core 40. The distance TC is the thickness of the elastic member 38 in the groove bottom 94 of the groove 86. The double arrow DB indicates the distance from the groove bottom 94 of the groove 86 to the bottom 56 of the core 40. The thickness TC and the distance DB are measured along the center line CL.

[0089] In the elastic crawler 30, from the viewpoint of reducing the weight of the elastic crawler 30, the ratio (TC / DB) of the thickness TC of the elastic member 38 in the groove bottom 94 of the groove 86 to the distance DB from the groove bottom 94 of the groove 86 to the bottom 56 of the core 40 is preferably 30% or more, and more preferably 40% or more. From the viewpoint of ensuring the rigidity of the guide protrusion 64, the ratio (TC / DB) is preferably 60% or less, and more preferably 50% or less.

[0090] As is clear from the above description, according to the present invention, it is possible to obtain the elastic crawler 30 which can ensure the rigidity and wear resistance of the guide protrusions 6 and achieve weight reduction.

[0091] Industrial Applicability

[0092] The elastic crawler belt described above can be applied to various crawler-type travel devices.

Claims

1. An elastic crawler, characterized in that: have: an endless belt-shaped crawler body; and A plurality of guide protrusions protrude from a running wheel passing surface formed on the inner peripheral surface of the crawler body. The crawler body includes a tension-resistant body extending in the circumferential direction. The guide protrusion includes a core body, The tensile body and the core are covered by elastic components, The maximum width of the core is smaller than the maximum width of the guide protrusion, The guide protrusion has a pair of outer side surfaces located on the outer sides in the width direction. Each outer side surface includes, at a portion thereof, a first core reflection region having a shape along the shape of the core, The first core reflection area is an area where the thickness of the elastic member represented by the distance from the outer side surface to the core is less than 0.5 mm. The guide protrusion has a groove that is recessed outward from the top surface. The groove wall of the groove includes, at a portion thereof, a second core reflection region having a shape along the shape of the core, The second core reflection area is an area where the thickness of the elastic member represented by the distance from the groove wall to the core is less than 0.5 mm. A ratio of an area of ​​the second core reflection region to an area of ​​the groove wall is 10% or less.

2. The elastic crawler according to claim 1, characterized in that: The core is exposed in the first core reflection area.

3. The elastic crawler according to claim 1 or 2, characterized in that: A ratio of an area of ​​the first core reflection region to an area of ​​the outer surface is 10% or less.

4. The elastic crawler according to claim 1 or 2, characterized in that: A ratio of a height from the runner passing surface to the first core reflection region to a height of the guide protrusion is 20% or more and less than 50%.

5. The elastic crawler according to claim 1 or 2, characterized in that: The core is exposed in the second core reflection area.

6. The elastic crawler according to claim 1 or 2, characterized in that: A ratio of a height from a groove bottom of the groove to the second core reflection region to a depth of the groove is 60% or more and 90% or less.

7. The elastic crawler according to claim 1 or 2, characterized in that: The bottom of the core is located outside the runner passing surface.

8. The elastic crawler according to claim 1 or 2, characterized in that: The crawler body includes a reinforcement layer on the outer side of the tension body, The reinforcement layer extends in a circumferential direction.

9. The elastic crawler according to claim 1 or 2, characterized in that: The location where the core shows the greatest width is between the top and bottom of the core.

10. The elastic crawler according to claim 1 or 2, characterized in that: The position where the core shows the maximum width is included in the first core reflection area.

11. The elastic crawler according to claim 1 or 2, characterized in that: The core is made of metal.

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