Elastic crawler

Abstract

To provide an elastic crawler which can easily obtain a core bar 18, prevents lateral displacement of the core bar 18, and causes less vibration.SOLUTION: An elastic crawler has a main belt, and a plurality of core bars 18 which are embedded in the main belt and aligned in a fore-and-aft direction. The core bar 18 has a main part 38, a guide projection 40 projecting inward from the main part 38, a track roller travel rail 42 which has a part thereof partially projecting forward or backward from the main part 38 and has a recess on the inside surface, and a lateral displacement preventive stoper 44 (46) projecting forward or backward from the main part 38. When the core bars 18 are viewed from inside, the contour of the lateral displacement preventive stopper 44 (46) does not overlap the contour of the guide projection 40, and does not overlap the contour of the track roller travel rail 42.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present specification discloses an elastic crawler. Specifically, the present specification relates to an elastic crawler for a traveling device having a main wheel and a rolling wheel. [Background Art]

[0002] A traveling device having an elastic crawler includes a main wheel and a rolling wheel. This traveling device includes, as the main wheels, a drive wheel and one or two driven wheels. Typically, the main wheel has an outer diameter larger than that of the rolling wheel. The rolling wheel is positioned between the drive wheel and the driven wheel or between the driven wheels. The elastic crawler is wound around between the main wheels.

[0003] This elastic crawler includes an endless main belt made of rubber or the like, lugs protruding from the outer circumferential surface of the main belt, and a rolling wheel guide protruding from the inner circumferential surface of the main belt. When the crawler travels, the crawler is guided by the rolling wheel and the rolling wheel guide.

[0004] Japanese Laid-Open Patent Publication No. 2003-146257 discloses a crawler having a core metal. The core metal has a projection for a rolling wheel guide. The core metal further has a recess at a position in contact with the rolling wheel. This recess can suppress vibration caused by traveling of the crawler. [Prior Art Literature] [Patent Literature]

[0005] [Patent Literature 1] Japanese Laid-Open Patent Publication No. 2003-146257 [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] In molds for casting mandrels (or their master molds) with recesses, the parting surface must be set up so that the recess does not become an undercut. Specifically, the direction of the mold division must roughly coincide with the depth direction of the recess.

[0007] A core with a stopper exists. The stopper prevents the core from shifting laterally from an adjacent core. In a mold for forming a core (or its master mold) that has both projections for wheel guides and a stopper, a core may be necessary to avoid undercuts. Forming using a core is complex.

[0008] The applicant's intention is to provide an elastic crawler in which the core metal can be easily obtained, the core metal is less prone to lateral displacement, and vibrations are reduced. [Means for solving the problem]

[0009] The elastic crawler disclosed herein is An endless, elastic main belt and This main belt has multiple core metals embedded in it, arranged along the front-to-back direction. It has. Each core metal is, Main part, A guide projection that protrudes inward from this main part, The wheel rail has a recess on its inner surface. and A lateral displacement prevention stopper protrudes forward or backward from this main body. It has the following characteristics: When this core metal is viewed from the inside, the contour of the anti-lateral displacement stopper does not overlap with the contour of the guide projection and does not overlap with the contour of the road wheel running rail. [Effects of the Invention]

[0010] In this elastic crawler, vibration can be suppressed because the wheel running rail has recesses. In this crawler, the stopper can suppress lateral displacement of the core metal. Since the contour of the anti-lateral displacement stopper does not overlap with the contour of the guide projection and also does not overlap with the contour of the wheel running rail, the core metal or its master mold can be easily manufactured. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is a schematic diagram showing a running device including an elastic crawler according to one embodiment. [Figure 2] Figure 2 is an enlarged view showing a portion of the elastic crawler in Figure 1. [Figure 3] Figure 3 is a cross-sectional view along the line III-III in Figure 2. [Figure 4] Figure 4 is a front view showing the core metal of the elastic crawler in Figure 3. [Figure 5] Figure 5 is a plan view showing the core metal in Figure 4. [Figure 6] Figure 6 is a bottom view showing the core metal in Figure 4. [Figure 7] Figure 7 is a left side view showing the core metal in Figure 4. [Figure 8] Figure 8 is a plan view showing a magnified portion of the core metal in Figure 5. [Figure 9] Figure 9 is a plan view showing a further enlarged view of a portion of the core metal shown in Figure 8. [Modes for carrying out the invention]

[0012] Preferred embodiments will be described in detail below, with reference to drawings as appropriate.

[0013] FIG. 1 shows a traveling device 2. This traveling device 2 includes a drive wheel 4, a driven wheel 6, a plurality of rolling wheels 8, and an elastic crawler 10. In the present embodiment, the drive wheel 4 is a sprocket. The traveling device 2 includes a driving means (such as an engine) not shown in the figure. The sprocket 4 is rotated by this driving means. The crawler 10 is wound around the sprocket 4 and the driven wheel 6. The rotation of the sprocket 4 causes the crawler 10 to rotate. When the crawler 10 rotates, the rolling wheels 8 guide the crawler 10. This guidance prevents meandering of the crawler 10. The rotation of the crawler 10 causes the device 2 to travel. Typical examples of the traveling device 2 include civil engineering equipment, construction equipment, and agricultural equipment. The traveling device 2 may include a plurality of driven wheels 6. The traveling device 2 may include a rolling wheel 8 positioned between the driven wheel 6 and another driven wheel 6.

[0014] FIGS. 2 and 3 show an elastic crawler 10. In each drawing, the arrow X represents the left-right direction, the arrow Y represents the front-rear direction, and the arrow Z represents the thickness direction. The left-right direction X is also the axial direction of the drive wheel 4. The front-rear direction is also the circumferential direction of the crawler 10. As shown in FIGS. 1 to 3, the crawler 10 includes a main belt 14, a plurality of lugs 16, a plurality of core bars 18, a plurality of rolling wheel guides 20, and a pair of tensile bodies 22.

[0015] The main belt 14 has an endless shape. The main belt 14 has an inner circumferential surface 24 and an outer circumferential surface 26. The main belt 14 further includes a pair of outer edges 28. What is indicated by the arrow Wm in FIG. 2 is the width of the main belt 14. The width Wm is the distance from the left outer edge 28 to the right outer edge 28. The width Wm of the main belt 14 is also the width of the crawler 10. The width Wm of a typical elastic crawler 10 is 100 mm or more and 600 mm or less.

[0016] The main belt 14 has multiple engagement holes 30. Each engagement hole 30 extends from the inner circumferential surface 24 to the outer circumferential surface 26. When the crawler 10 is running, the claws 32 of the sprocket 4 (see Figure 1) engage with these engagement holes 30. These claws 32 transmit driving force from the sprocket 4 to the main belt 14 via the core metal 18. The main belt 14 may have recesses instead of engagement holes 30. In the case of a main belt 14 with recesses, the claws 32 press against these recesses. The crawler 10 may have projections instead of engagement holes 30. In the case of a crawler 10 with projections, the claws 32 press against these projections.

[0017] As shown in Figure 2, the inner circumferential surface 24 has a first road wheel running zone 34a, a second road wheel running zone 34b, a first side zone 36a, and a second side zone 36b. The first road wheel running zone 34a is located to the left of the road wheel guide 20. The second road wheel running zone 34b is located to the right of the road wheel guide 20. In other words, each road wheel running zone 34 is located axially outward from the road wheel guide 20. The first side zone 36a is located to the left of the first road wheel running zone 34a. The second side zone 36b is located to the right of the second road wheel running zone 34b. In other words, each side zone 36 is located axially outward from the road wheel running zone 34. Each road wheel running zone 34 extends in the circumferential direction. Each side zone 36 extends in the circumferential direction. As shown in Figure 3, when the running gear 2 moves, the outer circumferential surface of the road wheel 8 comes into contact with the road wheel running zone 34.

[0018] The main belt 14 is formed from an elastic material. Rubber, synthetic resin, elastomer, etc., can be used for the main belt 14. A typical material for the main belt 14 is a crosslinked rubber composition.

[0019] As shown in Figure 1, multiple lugs 16 are arranged along the circumferential direction. These lugs 16 are arranged at equal pitches. As shown in Figures 1 and 3, each lug 16 protrudes from the outer circumferential surface 26 of the main belt 14. The material of the lugs 16 is different from the material of the main belt 14. The material of the lugs 16 may be the same as the material of the main belt 14. A typical material for the lugs 16 is a crosslinked rubber composition.

[0020] As shown in Figure 2, multiple core metals 18 are arranged along the front-to-back direction. In this embodiment, these core metals 18 are arranged at equal pitches. Each core metal 18 is located at the center in the width direction. The core metals 18 are generally embedded in the main belt 14. A portion of the core metals 18 is exposed from the main belt 14. In this specification, the term "embedded" is used, including the case where a portion of the core metals 18 is exposed from the main belt 14. The core metals 18 are rigid. Typical materials for the core metals 18 are metals such as steel and stainless steel.

[0021] As shown in Figure 4-7, the core metal 18 has a main body 38, a pair of guide projections 40, a pair of wheel running rails 42, a pair of first stoppers 44, and a pair of second stoppers 46. The main body 38 has a center 48 and a pair of wings 50. Each wing 50 protrudes from the center 48 in the left-right direction.

[0022] As shown in Figure 4, each guide projection 40 protrudes inward (upward in Figure 4) from the main portion 38. As is clear from Figure 5, when the core metal 18 is viewed from the inside, a portion of the contour of the guide projection 40 extends beyond the contour of the main portion 38. In Figure 5, the guide projection 40 located on the left side has its front (upper) contour positioned further forward than the contour of the main portion 38. In Figure 5, the guide projection 40 located on the right side has its rear (lower) contour positioned further back than the contour of the main portion 38. In this embodiment, the shape of the right guide projection 40 is rotationally symmetric to the shape of the left guide projection 40. The right guide projection 40 may have a shape that is not symmetrical to the shape of the left guide projection 40. The left-right position of the guide projections 40 is determined according to the specifications of the running gear 2 (particularly the specifications of the road wheels 8).

[0023] Each rail 42 is located directly below the wheel running zone 34 (see Figure 2). In this embodiment, as is clear from Figure 5, when the core metal 18 is viewed from the inside, a portion of the rail 42 protrudes from the main body 38. The rail 42 located on the left side in Figure 5 has a rear (lower) contour that protrudes further back than the contour of the main body 38. The rail 42 located on the right side in Figure 5 has a front (upper) contour that protrudes further forward than the contour of the main body 38. In this embodiment, the shape of the right rail 42 is rotationally symmetric to the shape of the left rail 42. The right rail 42 may have a shape that is not symmetrical to the shape of the left rail 42. The left-right position of the rails 42 is determined according to the specifications of the running gear 2 (particularly the specifications of the wheels 8).

[0024] As shown in Figures 3 and 7, the rail 42 has a recess 52. In this recess 52, the surface of the rail 42 is curved outward (downward in Figure 7). When the device 2 is running, the road wheels 8 enter this recess 52 (or the rubber covering this recess 52). This recess 52 contributes to the smooth rotation of the road wheels 8. This recess 52 can suppress vibrations of the running gear 2. From the viewpoint of vibration suppression, the depth of the recess 52 is preferably 0.2 mm or more and 2.0 mm or less.

[0025] As shown in Figure 5, each first stopper 44 protrudes from the main part 38. The first stopper 44 located on the left side in Figure 5 protrudes forward from the main part 38. The first stopper 44 located on the right side in Figure 5 protrudes backward from the main part 38. In this embodiment, the shape of the right first stopper 44 is rotationally symmetric to the shape of the left first stopper 44. The right first stopper 44 may have a shape that is not symmetrical to the shape of the left first stopper 44.

[0026] Each second stopper 46 protrudes from the main part 38. In Figure 5, the second stopper 46 located on the left side protrudes backward from the main part 38. In Figure 5, the second stopper 46 located on the right side protrudes forward from the main part 38. In this embodiment, the shape of the right second stopper 46 is rotationally symmetric to the shape of the left second stopper 46. The right second stopper 46 may have a shape that is not symmetrical to the shape of the left second stopper 46.

[0027] As is clear from Figure 2, the first stopper 44 of the core metal 18 is in contact with the second stopper 46 of the core metal 18 adjacent to it. The second stopper 46 of the core metal 18 is in contact with the first stopper 44 of the core metal 18 adjacent to it. The contact between the first stopper 44 and the second stopper 46 can suppress lateral displacement between the core metal 18 and the core metal 18 adjacent to it. In this specification, the first stopper 44 and the second stopper 46 are each referred to as "lateral displacement prevention stoppers".

[0028] As shown in Figures 1 and 2, a plurality of road wheel guides 20 are arranged along the longitudinal direction. These road wheel guides 20 are arranged at equal pitches. Each road wheel guide 20 is located at the center in the lateral direction. As shown in Figure 3, this road wheel guide 20 protrudes from the inner circumferential surface 24 of the main belt 14. This road wheel guide 20 has a pair of knobs 54. As shown in Figure 3, each knob 54 includes a guide projection 40 of the core metal 18. This knob 54 further includes a portion of the main belt 14. The road wheel guide 20 may have knobs 54 that do not include the main belt 14. In other words, the guide projection 40 may be completely exposed on the knob 54.

[0029] As shown in Figure 3, each tensile member 22 has multiple cords 56. Each cord 56 extends in the front-to-back direction. These cords 56 can suppress excessive stretching of the main belt 14. Typical materials for the cords 56 are metals such as steel and stainless steel. The cords 56 may also be formed from organic fibers.

[0030] As is clear from Figure 5, the contour of the first stopper 44, when viewed from the inside, does not overlap with the contour of the guide projection 40, nor with the contour of the road wheel running rail 42. The contour of the second stopper 46, when viewed from the inside, also does not overlap with the contour of the guide projection 40, nor with the contour of the road wheel running rail 42. This mandrel 18 (or master mold) can be formed using a mold that is divided in the thickness direction (Z direction). Figure 4 shows the parting line PL of this mold. In this mold, the recess 52 is not an undercut. A core for the recess 52 is not required in molding using this mold. This mandrel 18 can be obtained easily and at low cost.

[0031] Figure 8 shows a magnified view of a portion of the core metal 18. As shown in Figure 8, the first stopper 44 has a butt 58 (handle portion) and a tip 60 (tip portion). The butt 58 is continuous with the main portion 38 and extends generally forward from the main portion 38. The tip 60 is continuous with the butt 58 and extends generally forward from this butt 58. The butt 58 has a first side surface 62 and a second side surface 64. The first side surface 62 is inclined with respect to the front-rear direction. Specifically, the first side surface 62 is angled to the left as it approaches the rear side (lower side in Figure 5). In other words, as the first side surface 62 approaches the main portion 38 in the front-rear direction, it moves away from the guide projection 40 in the left-right direction.

[0032] In this embodiment, the second side surface 64 is also inclined with respect to the front-rear direction. Specifically, the second side surface 64 is angled to the left as it approaches the rear side (the lower side in Figure 5). In other words, as the second side surface 64 approaches the main portion 38 in the front-rear direction, it moves away from the guide projection 40 in the left-right direction.

[0033] In Figure 8, the symbol Sb represents a line segment passing through the rightmost point Pb of the butt 58. The line segment Sb extends in the front-to-back direction. The symbol St represents a line segment passing through the rightmost point Pt of the tip 60. The line segment St extends in the front-to-back direction. The line segment St is located to the right of the line segment Sb. The symbol Pc represents the intersection point of the line segment St and the contour of the main part 38. If the first side surface 62 extended in the front-to-back direction along the line segment St without inclination, the first side surface 62 would reach the intersection point Pc. In this case, the contour of the first stopper 44 would overlap with the contour of the guide projection 40. In this embodiment, this overlap is avoided by the inclination of the first side surface 62.

[0034] Because this overlap is avoided, the left-right position of tip 60 has a high degree of freedom. Tip 60 can be positioned in an appropriate location to suppress lateral slippage. In this crawler 10, the core metal 18 is less likely to slip laterally.

[0035] Figure 9 shows a magnified view of a portion of the core metal 18. In Figure 9, arrow Hs represents the height of the first stopper 44, and arrow Hb represents the height of the butt 58. The ratio of height Hb to height Hs (Hb / Hs) is preferably 0.70 or less. The first stopper 44 with this ratio (Hb / Hs) of 0.70 or less has excellent strength. From this viewpoint, this ratio (Hb / Hs) is more preferably 0.65 or less, and particularly preferably 0.60 or less. From the viewpoint of avoiding overlap, this ratio (Hb / Hs) is preferably 0.40 or more.

[0036] In Figure 9, arrow Ws represents the width of the first stopper 44, and arrow Lb represents the left-right distance of the first side surface 62. The width Ws is measured excluding the rounding (R2) described later. The ratio of the distance Lb to the width Ws (Lb / Ws) is preferably 0.40 or less. A first stopper 44 with this ratio (Lb / Ws) of 0.40 or less has excellent strength. From this viewpoint, this ratio (Lb / Ws) is more preferably 0.35 or less, and particularly preferably 0.30 or less. From the viewpoint of avoiding overlap, this ratio (Lb / Ws) is preferably 0.10 or more.

[0037] The core metal 18 has a curve between the main portion 38 and the first side surface 62. In Figure 9, arrow R1 represents the radius of curvature of this curve. The radius of curvature R1 is preferably 1.0 mm or more. Core metal 18 with a radius of curvature R1 of 1.0 mm or more has excellent strength. From this viewpoint, the radius of curvature R1 is preferably 2.0 mm or more, and particularly preferably 2.5 mm or more. From the viewpoint of avoiding overlap, the radius of curvature R1 is preferably 6.0 mm or less.

[0038] The core metal 18 has a curve between the main part 38 and the second side surface 64. In Figure 9, the arrow R2 represents the radius of curvature of this curve. The radius of curvature R2 is preferably 2.0 mm or more. Core metal 18 with a radius of curvature R2 of 2.0 mm or more has excellent strength. From this viewpoint, the radius of curvature R2 is preferably 4.0 mm or more, and particularly preferably 5.0 mm or more. From the viewpoint of lightweight core metal 18, the radius of curvature R2 is preferably 10.0 mm or less.

[0039] [Disclosure items] Each of the following items is a disclosure of a preferred embodiment.

[0040] [Item 1] An endless, elastic main belt and Multiple core metals embedded in the main belt and arranged along the front-to-back direction. It is equipped with, Each core metal, Main part, Guide projections protruding inward from the main body mentioned above, The wheel rail has a recess on its inner surface. and A lateral displacement prevention stopper protruding forward or backward from the main body mentioned above. It has, An elastic crawler in which, when the core metal is viewed from the inside, the contour of the anti-lateral displacement stopper does not overlap with the contour of the guide projection and does not overlap with the contour of the wheel running rail.

[0041] [Item 2] The above-mentioned lateral displacement prevention stopper has a butt that is continuous with the main body and a tip that is continuous with this butt. The sides of the bat described above are inclined in the front-to-back direction. The elastic crawler according to item 1, wherein the slope of the side surface prevents overlap between the contour of the anti-lateral displacement stopper, the contour of the guide projection, or the contour of the wheel running rail.

[0042] [Item 3] The elastic crawler described in item 2, wherein the ratio of the height Hb of the bat to the height Hs of the above-mentioned lateral displacement prevention stopper (Hb / Hs) is 0.70 or less.

[0043] [Item 4] An elastic crawler according to item 2 or 3, wherein the ratio of the lateral distance Lb of the side surface to the width Ws of the above-mentioned lateral displacement prevention stopper (Lb / Ws) is 0.40 or less.

[0044] [Item 5] An elastic crawler according to any one of items 2 to 4, wherein the core metal has a rounded edge at the boundary between the main part and the side surface, and the radius of curvature R1 of this rounded edge is 1.0 mm or more.

[0045] [Item 6] Main part, Guide projections protruding inward from the main body mentioned above, The wheel rail has a recess on its inner surface. and A lateral displacement prevention stopper protruding forward or backward from the main body mentioned above. It has, A core metal for an elastic crawler, wherein, when viewed from the inside, the contour of the anti-lateral displacement stopper does not overlap with the contour of the guide projection and does not overlap with the contour of the wheel running rail. [Industrial applicability]

[0046] The aforementioned elastic crawler is suitable for various types of running gear. This crawler is particularly suitable for civil engineering and construction machinery. [Explanation of Symbols]

[0047] 2. Driving system 4. Drive wheel (sprocket) 6. Driven wheel 8...Road wheels 10. Elastic crawler 14. Main belt 16...rug 18. Mandrel 20...Road Wheel Guide 22...tensile body 24...Inner peripheral surface 26...outer surface 28...outer edge 30...Engagement holes 34a...First wheel running zone 34b...Second road wheel running zone 38... Main part 40... Guide protrusions 42...rail 44...First stopper 46...Second stopper 52 recesses 54...54 56...code 58... Bat 60... Tip 62...first aspect 64...Second side

Claims

1. An endless, elastic main belt and Multiple core metals embedded in the main belt and arranged along the front-to-back direction. It is equipped with, Each core metal, Main part, Guide projections protruding inward from the main body mentioned above, The wheel rail has a recess on its inner surface. and A lateral displacement prevention stopper protruding forward or backward from the main body mentioned above. It has, When the above core metal is viewed from the inside, the contour of the above lateral displacement prevention stopper does not overlap with the contour of the above guide projection, nor does it overlap with the contour of the above road wheel running rail. An elastic crawler in which the above-mentioned lateral displacement prevention stopper has a butt continuous with the main part and a tip continuous with the butt, the side surface of the butt is inclined with respect to the front-rear direction, and the inclination of the side surface prevents overlap between the contour of the lateral displacement prevention stopper and the contour of the guide projection or the contour of the wheel running rail.

2. The elastic crawler according to claim 1, wherein the ratio of the height Hb of the bat to the height Hs of the lateral displacement prevention stopper (Hb / Hs) is 0.70 or less.

3. The elastic crawler according to claim 1 or 2, wherein the ratio of the left-right distance Lb of the side surface to the width Ws of the above-mentioned lateral displacement prevention stopper (Lb / Ws) is 0.40 or less.

4. The elastic crawler according to claim 1 or 2, wherein the core metal has a rounded edge at the boundary between the main part and the side surface, and the radius of curvature R1 of this rounded edge is 1.0 mm or more.

5. Main part, Guide projections protruding inward from the main body mentioned above, The wheel rail has a recess on its inner surface. and A lateral displacement prevention stopper protruding forward or backward from the main body mentioned above. It has, When viewed from the inside, the contour of the above-mentioned lateral displacement prevention stopper does not overlap with the contour of the above-mentioned guide projection, nor does it overlap with the contour of the above-mentioned road wheel running rail. The above-mentioned lateral displacement prevention stopper has a butt continuous with the main body and a tip continuous with the butt, the side surface of the butt is inclined with respect to the front-rear direction, and the inclination of the side surface prevents overlap between the contour of the lateral displacement prevention stopper and the contour of the guide projection or the contour of the wheel running rail.

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