Solid Tire

Abstract

To provide a solid tire configured so that an end part of a joint surface of a tread is suppressed from peeling off from a wheel.SOLUTION: In a solid tire 2, a wheel 6 has an inclined surface 26 positioned between a side surface 24 and an outer peripheral surface 20 and inclined toward outside in a radial direction as going toward inside in an axial direction. A ratio (Te / T) of a thickness Te in the radial direction at an outer end in the axial direction of a tread 4 to a thickness T in the radial direction in an equator is 0.070 or more and 0.25 or less. Structures of the wheel 6 and of the tread 4 can effectively relax concentration of stress onto an end part of a joint surface of the tread 4. This can suppress the end part of the joint surface of the tread 4 from peeling from the wheel 6, in the tire 2.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] This specification discloses a solid tire. [Background technology]

[0002] Solid tires (also called solid-core tires) are mainly used for industrial vehicles such as transport equipment in production facilities and forklifts. Solid tires include a wheel and a tread mounted on the wheel. The tread is typically made of a rubber composition.

[0003] When a solid tire is subjected to a large load, the tread bends. This bending tends to cause stress concentration near the axially outer end of the interface between the tread and the wheel (the edge of the tread interface). Stress concentration at the edge of the tread interface can cause the edge of the tread interface to separate from the wheel. Japanese Patent Application Laid-Open No. 2005-349872 discloses a study on a solid tire that alleviates stress concentration at the edge of the tread interface. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP2005-349872A Summary of the Invention [Problem to be solved by the invention]

[0005] Solid tires are required to effectively prevent the edge of the tread joint surface from peeling off from the wheel.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a solid tire in which the edge of the mating surface of the tread is prevented from peeling off from the wheel. [Means for solving the problem]

[0007] A preferred solid tire comprises an annular wheel and a tread located radially outward of the wheel and having a tread surface in contact with a road surface, the wheel having a side surface, an outer peripheral surface, and an inclined surface located between the side surface and the outer peripheral surface and inclined radially outward as it approaches axially inward, and the ratio (Te / T) of the radial thickness Te at an axially outer end of the tread to the radial thickness T at the equator is 0.070 or greater and 0.25 or less. Effect of the Invention

[0008] In this solid tire, the concentration of stress at the joint edge of the tread is effectively mitigated by providing an inclined surface on the wheel and by setting the ratio (Te / T) of the radial thickness Te at the axially outer end of the tread to the radial thickness T at the equator to 0.070 or more and 0.25 or less. In this tire, separation of the joint edge of the tread from the wheel is suppressed. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing a solid tire according to one embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a cross section perpendicular to the circumferential direction of the tire in FIG. [Diagram 3] FIG. 3 is an enlarged cross-sectional view of a portion of FIG. [Figure 4] FIG. 4 is a cross-sectional view showing a solid tire according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, preferred embodiments will be described in detail with reference to the drawings as appropriate.

[0011] FIG. 1 is a perspective view showing a solid tire 2. In FIG. 1, an arrow X indicates the axial direction of the tire 2, and an arrow A indicates the circumferential direction of the tire 2. FIG. 2 is a cross-sectional view showing a cross section perpendicular to the circumferential direction of the tire 2 in FIG. 1. In FIG. 2, an arrow X indicates the axial direction of the tire 2, an arrow Y indicates the radial direction of the tire 2, and a direction perpendicular to the paper surface is the circumferential direction of the tire 2. In FIG. 2, a dashed dotted line CL represents the equatorial plane of the tire 2. This tire 2 does not have a cavity for putting air in. This tire 2 is a solid tire 2. As shown in FIGS. 1 and 2, this tire 2 includes a tread 4 and a wheel 6.

[0012] The tread 4 has an annular shape. The tread 4 is attached to the radially outer side of the wheel 6. The tread 4 is made of crosslinked rubber having excellent wear resistance and gripping properties. Examples of the base rubber of the tread 4 include natural rubber (NR), polyisoprene (IR), polybutadiene (BR) and urethane rubber (U). The material of the tread 4 may be a thermoplastic elastomer.

[0013] The tread 4 includes a tread surface 8 that comes into contact with the road surface, a joint surface 10 that comes into contact with the wheel 6, and a pair of side surfaces 12. Each side surface 12 is located between the tread surface 8 and the joint surface 10. The tread surface 8, the joint surface 10, and the side surfaces 12 each extend in the circumferential direction. In the embodiment of FIG. 1, grooves 14 are formed in the tread surface 8. The grooves 14 form a tread pattern. The grooves 14 may not be formed in the tread surface 8.

[0014] Fig. 3 shows an enlarged view of the vicinity of the axially outer end of the joint surface 10. In Fig. 3, the reference symbol P1 represents the radially inner end of the side surface 12 of the tread 4. The reference symbol P1 also represents the axially outer end of the joint surface 10. In this specification, the position represented by the reference symbol P1 is referred to as the "end point P1."

[0015] As shown in FIG. 3, each side surface 12 has an end portion 16 and a curved portion 18. The end portion 16 extends in a radial direction from an end point P1. The end portion 16 extends in a radial direction from an axially outer end of the joining surface 10. The end portion 16 has a straight shape in a cross section perpendicular to the circumferential direction. The curved portion 18 extends from an outer end 19 of the end portion 16. The curved portion 18 is inclined so as to extend radially outward as it extends axially inward. In this embodiment, the curved portion 18 has an inwardly convex circular arc shape in a cross section perpendicular to the circumferential direction.

[0016] In Fig. 3, the double-headed arrow Te represents the radial thickness of the tread 4 at the axially outer end. In detail, the thickness Te is the distance in the radial direction between the end point P1 and the outer end 19 of the end portion 16. In Fig. 2, the double-headed arrow T represents the radial thickness of the tread 4 at the equator. In the tire 2, the ratio (Te / T) of the thickness Te to the thickness T is equal to or greater than 0.070 and equal to or less than 0.25.

[0017] The wheel 6 has an annular shape. The wheel 6 is typically made of metal. Preferable materials for the wheel 6 include steel and aluminum alloy. The wheel 6 may also be made of synthetic resin.

[0018] The wheel 6 has an outer peripheral surface 20, an inner peripheral surface 22, a pair of side surfaces 24, and a pair of inclined surfaces 26. The outer peripheral surface 20 is covered by the tread 4. The outer peripheral surface 20 is in contact with the joint surface 10 of the tread 4. The inner peripheral surface 22 forms the inner peripheral surface of the tire 2. The outer peripheral surface 20, the inner peripheral surface 22, the side surfaces 24, and the inclined surfaces 26 each extend in the circumferential direction.

[0019] As shown in Fig. 2, each side surface 24 extends radially from an axially outer end of the inner circumferential surface 22. As shown in Fig. 3, the side surface 24 is continuous with the end 16 of the tread 4. That is, the end point P1 coincides with the radially outer end of the side surface 24 of the wheel 6. The side surface 24 is connected to the end 16 in a straight line.

[0020] Each inclined surface 26 is located between the corresponding side surface 24 and the outer circumferential surface 20. The inclined surface 26 extends from an end point P1. That is, the end point P1 is an axially outer end of the inclined surface 26. The inclined surface 26 is inclined so as to move radially outward as it moves axially inward. As shown in Fig. 3, in this embodiment, in a cross section perpendicular to the circumferential direction, the inclined surface 26 has an outwardly convex arc shape.

[0021] In FIG. 3 , the reference symbol P2 denotes the axially inner end of the inclined surface 26. The reference symbol P2 also denotes the axially outer end of the outer peripheral surface 20. In this specification, the position represented by the reference symbol P2 is referred to as the "end point P2." At the end point P2, the inclined surface 26 is connected to the outer peripheral surface 20. The inclined surface 26 is covered by the tread 4. The inclined surface 26 is in contact with the joint surface 10 of the tread 4.

[0022] The effects of this embodiment will be described below.

[0023] In the solid tire 2 according to the present disclosure, the wheel 6 has an inclined surface 26 located between the side surface 24 and the outer peripheral surface 20, which is inclined so as to move radially outward as it moves axially inward. This inclined surface 26 prevents the concentration of stress applied to the vicinity of the axially outer end of the joint surface 10 of the tread 4 (the joint surface end of the tread 4). Furthermore, in this solid tire, the ratio (Te / T) of the thickness Te to the thickness T is 0.070 or more and 0.25 or less. By providing the inclined surface 26 on the wheel 6 and appropriately setting the thickness Te of the tread 4 at the position in contact with this inclined surface 26, the concentration of stress at the joint surface end of the tread 4 is more effectively prevented. In this solid tire 2, the joint surface end of the tread 4 is prevented from peeling off from the wheel 6.

[0024] The ratio (Te / T) is more preferably 0.10 or greater. By setting the ratio (Te / T) to 0.10 or greater, the tread 4 has a thickness capable of withstanding stress loads at the axially outer end. In the solid tire 2, the end of the joint surface of the tread 4 is more effectively prevented from peeling off from the wheel 6. From this viewpoint, the ratio (Te / T) is more preferably 0.14 or greater. The ratio (Te / T) is more preferably 0.21 or less. By setting the ratio (Te / T) to 0.21 or less, the concentration of stress applied to the end of the joint surface of the tread 4 is more effectively alleviated. In the solid tire 2, the end of the joint surface of the tread 4 is prevented from peeling off from the wheel 6. From this viewpoint, the ratio (Te / T) is more preferably 0.18 or less.

[0025] In Fig. 3, a double-headed arrow Wr indicates the radial width of the inclined surface 26. Specifically, the width Wr is the radial distance between the end point P1 and the end point P2. The ratio (Wr / T) of the width Wr to the thickness T is preferably equal to or greater than 0.050. By setting the ratio (Wr / T) to be equal to or greater than 0.050, the inclined surface 26 effectively reduces the concentration of stress at the joint surface end of the tread 4. From this viewpoint, the ratio (Wr / T) is more preferably equal to or greater than 0.060, and further preferably equal to or greater than 0.080.

[0026] Increasing the ratio (Wr / T) reduces the radial thickness at the axial end of the wheel 6. This may affect the durability of the wheel 6. In order to ensure the durability of the wheel 6, it is possible to increase the radial thickness of the entire wheel 6. However, this may affect the cost of the wheel 6.

[0027] The ratio (Wr / T) is preferably 0.15 or less. By keeping the ratio (Wr / T) at 0.15 or less, it is possible to maintain excellent durability while suppressing increases in costs. From this viewpoint, the ratio (Wr / T) is more preferably 0.14 or less, and further preferably 0.12 or less.

[0028] In FIG. 3, a double-headed arrow Wa indicates the axial width of the inclined surface 26. More specifically, the width Wa is the axial distance between the end point P1 and the end point P2. The ratio (Wa / Wr) of the width Wa to the width Wr is preferably 0.50 or more. By setting the ratio (Wa / Wr) to 0.50 or more, the portion of the tread 4 present on the axial outside of the inclined surface 26 has a size capable of withstanding the applied stress. In the solid tire 2, the end of the joint surface of the tread 4 is prevented from peeling off from the wheel 6. From this viewpoint, the ratio (Wa / Wr) is more preferably 0.60 or more, and further preferably 0.80 or more. The ratio (Wa / Wr) is preferably 1.5 or less. By setting the ratio (Wa / Wr) to 1.5 or less, the inclined surface 26 effectively relieves the concentration of stress on the end of the joint surface of the tread 4. From this viewpoint, the ratio (Wa / Wr) is more preferably 1.4 or less, and further preferably 1.2 or less.

[0029] 3, the symbol V represents an imaginary line extending in the radial direction through the end point P2. The double-headed arrow Ti represents the radial thickness of the tread 4 at the end point P2. The thickness Ti is the thickness of the tread 4 measured along the imaginary line V.

[0030] The ratio (Ti / Te) of the thickness Ti to the thickness Te is preferably 0.70 or more. By setting the ratio (Ti / Te) to 0.70 or more, the tread 4 has a thickness capable of withstanding the stress applied at the axially inner end of the inclined surface 26. In the solid tire 2, the end of the joint surface of the tread 4 is prevented from peeling off from the wheel 6. From this viewpoint, the ratio (Ti / Te) is more preferably 0.90 or more, and further preferably 1.1 or more. The ratio (Ti / Te) is preferably 2.0 or less. By setting the ratio (Ti / Te) to 2.0 or less, the concentration of the stress applied to the end of the joint surface of the tread 4 is effectively alleviated. In the solid tire 2, the end of the joint surface of the tread 4 is prevented from peeling off from the wheel 6. From this viewpoint, the ratio (Ti / Te) is more preferably 1.7 or less, and further preferably 1.5 or less.

[0031] In FIG. 3, an arrow R indicates the radius of curvature of the curved portion 18. The radius of curvature R is preferably 10 mm or more. By making the radius of curvature R 10 mm or more, the concentration of stress applied to the joint surface end of the tread 4 is effectively alleviated. From this viewpoint, the radius of curvature R is more preferably 15 mm or more, and further preferably 20 mm or more. The radius of curvature R is preferably 40 mm or less. By making the radius of curvature R 40 mm or less, the tread 4 has a thickness capable of withstanding the applied stress in the vicinity of the outer end in the axial direction. The tread 4 has excellent durability. From this viewpoint, the radius of curvature R is more preferably 35 mm or less, and further preferably 30 mm or less.

[0032] 4 is a cross-sectional view showing a solid tire 30 according to another embodiment. The tire 30 includes a tread 32 and a wheel 34. The wheel 34 includes an inclined surface 40 between an outer circumferential surface 36 and a side surface 38. In the tire 30, the shape of the inclined surface 40 of the wheel 34 is different from that of the tire 2 in FIG.

[0033] The inclined surface 40 is inclined so as to move radially outward as it moves axially inward. As shown in Fig. 4, in this embodiment, the inclined surface 40 is linear in a cross section perpendicular to the circumferential direction. The linear inclined surface 40 effectively relieves the concentration of stress applied to the joint surface end of the tread 32. In this solid tire 30, the joint surface end of the tread 32 is prevented from peeling off from the wheel 34.

[0034] In addition, in the solid tire 30 of the embodiment in Figure 4, the preferable ranges of the ratio (Te / T), ratio (Wr / T), ratio (Wa / Wr), ratio (Ti / Te) and radius of curvature R are the same as those of the solid tire 2 of the embodiment in Figure 3. EXAMPLES

[0035] The effects of the solid tires according to the examples will be explained below, but the scope of the present specification should not be construed as being limited based on the description of these examples.

[0036] [Example 1] A solid tire of Example 1 was obtained with the specifications shown in Table 1 below. The outer diameter of this tire measured at the equatorial plane was 267 mm, and the tread thickness T was 42 mm. The inner diameter of the wheel was 165 mm. The base rubber of the tread was natural rubber.

[0037] [Comparative Example 1] In this tire, the wheel does not have an inclined surface. The side surface of the wheel is connected to the outer circumferential surface. The ratio (Te / T) of this tire was as shown in Table 1. Other than these, the tire of Comparative Example 1 was obtained in the same manner as in Example 1.

[0038] [Comparative Example 2-3, Example 2-4] Tires of Comparative Example 2-3 and Example 2-4 were obtained in the same manner as in Example 1 except that the ratio (Te / T) was as shown in Table 1.

[0039] [Example 5] A tire of Example 5 was obtained in the same manner as Example 1, except that the inclined surface had an arcuate shape.

[0040] [Examples 6-7] The tires of Examples 6-7 were obtained in the same manner as in Example 3, except that the values ​​of the ratio (Wr / T), ratio (Wr / T), ratio (Ti / Te), radius R, and the shape of the inclined surface were as shown in Table 2.

[0041] [Example 8] A tire of Example 8 was obtained in the same manner as in Example 1, except that the value of the ratio (Ti / Te), the value of the radius R, and the shape of the inclined surface were as shown in Table 2.

[0042] [Tread peeling] This tire was mounted on the drive wheels of a vehicle (a 2.5-ton counterweight forklift). The vehicle was loaded so that a load of 28.5 kN was applied to the tire. This vehicle was repeatedly driven in a slalom pattern on a flat asphalt road. The vehicle's speed at this time was 8 km / h. The running time until separation occurred at the edge of the tread joint was measured. The results are shown in Table 1-2 on a scale of 1 to 10. The higher the number, the longer the running time. The higher the number, the more preferable it is.

[0043] [Table 1]

[0044] [Table 2]

[0045] As shown in Table 1-2, the tire of the embodiment example has less tread separation than the tire of the comparative example. From this evaluation result, the superiority of this solid tire is clear.

[0046] [Disclosure items] The following section discloses preferred embodiments.

[0047] [Item 1] A solid tire comprising: an annular wheel; and a tread having a tread surface located radially outward of the wheel and in contact with a road surface, the wheel having a side surface, an outer peripheral surface, and an inclined surface located between the side surface and the outer peripheral surface, the inclined surface inclining radially outward as it moves axially inward, the ratio (Te / T) of the radial thickness Te at an axially outer end of the tread to the radial thickness T at the equator being 0.070 or greater and 0.25 or less.

[0048] [Item 2] 2. The solid tire according to item 1, wherein a ratio (Wr / T) of a radial width Wr of the inclined surface to the thickness T is 0.050 or more and 0.15 or less, and a ratio (Wa / Wr) of an axial width Wa of the inclined surface to the width Wr is 0.50 or more and 1.5 or less.

[0049] [Item 3] 3. The solid tire according to item 1 or 2, wherein the inclined surface has a straight shape in a cross section perpendicular to the circumferential direction.

[0050] [Item 4] 4. The solid tire according to any one of items 1 to 3, wherein a ratio (Ti / Te) of a radial thickness Ti of the tread at an axially inner end of the inclined surface to the thickness Te is 0.70 or greater and 2.0 or less.

[0051] [Item 5] 5. The solid tire according to any one of items 1 to 4, wherein the tread has a side surface, the side surface of the tread has an end portion extending radially from an inner end of the side surface and a curved portion extending from an outer end of the end portion, the curved portion having an inwardly convex arc shape in a cross section perpendicular to the circumferential direction, and a radius of curvature of the curved portion is 10 mm or more and 40 mm or less. [Industrial Applicability]

[0052] The above-mentioned solid tire can be mounted on a conveying device in a production line or an industrial vehicle. [Explanation of symbols]

[0053] 2.30··Solid tires 4, 32... tread 6, 34... Wheels 8. Tread surface 10...Joint surface 12. Tread side 14...Groove 16 End 18... Curved section 20, 36...outer surface 22...Inner surface 24, 38... Wheel side 26, 40...Slope

Claims

1. The tire comprises an annular wheel and a tread located radially outward of the wheel and having a tread surface that contacts a road surface, The wheel has a side surface, an outer circumferential surface, and an inclined surface located between the side surface and the outer circumferential surface and inclined so as to extend radially outward as it extends axially inward, The solid tire has a ratio (Te / T) of a radial thickness Te at an axially outer end of the tread to a radial thickness T at the equator of the tread, which is 0.070 or greater and 0.25 or less.

2. a ratio (Wr / T) of a radial width Wr of the inclined surface to the thickness T is 0.050 or more and 0.15 or less, 2. The solid tire according to claim 1, wherein a ratio (Wa / Wr) of an axial width Wa of the inclined surface to the width Wr is equal to or greater than 0.50 and equal to or less than 1.

5.

3. 3. The solid tire according to claim 1, wherein the inclined surface is linear in a cross section perpendicular to the circumferential direction.

4. 4. The solid tire according to claim 1, wherein a ratio (Ti / Te) of a radial thickness Ti of the tread at an axially inner end of the inclined surface to the thickness Te is 0.70 or more and 2.0 or less.

5. the tread having a side surface, a side surface of the tread having an end portion extending radially from an inner end of the side surface and a curved portion extending from an outer end of the end portion; 5. The solid tire according to claim 1, wherein the curved portion has an inwardly convex arc shape in a cross section perpendicular to the circumferential direction, and the curved portion has a radius of curvature of 10 mm or more and 40 mm or less.

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