Non-puncture tire

Abstract

To provide a non-puncture tire having improved assemblability and ride quality.SOLUTION: A non-puncture tire 10 has a cavity 12 inside a tire member 11. In an outer side of the cavity 12 being a ground plane side of the tire member 11, a first member 13 formed of sponge rubber by extrusion is mounted in a ring shape. In an inner side of the cavity 12, a second member 14 formed in a ring shape is mounted and divided into two. The first member 13 and the second member 14 are arranged so as to contact with each other in the vicinity of a center portion of the outer side and the inner side of the cavity 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a puncture-proof tire for a vehicle. [Background technology]

[0002] Conventionally, puncture-proof tires that do not get punctured, as opposed to air-filled tires, have been known to include tires in which an extruded piece of sponge rubber is inserted inside the tire as a tube (for example, Patent Documents 1 and 2), tires in which urethane resin or epoxy resin is injected inside the tire and hardened (for example, Patent Document 3), and tires in which the entire tire is molded in a mold.

[0003] Extruded sponge rubber inserts offer better ride comfort due to their superior cushioning compared to resin-injected or molded inserts, but they have the problem of being difficult to assemble when inserted inside the tire. Tire sizes vary depending on the vehicle. For example, as shown in Figure 7, when considering the A / B value, which shows the relationship between the tire's outer diameter (strictly speaking, the value minus the thickness of the tire's outer shell) A and its inner diameter B, the higher the A / B value, the stronger the force required, as the approximately straight extrusion product must be bent while being inserted. In other words, compared to bicycles (A / B=1.2) and wheelchairs (A / B=1.3), it was generally difficult to assemble sponge rubber extrusions inside tires for vehicles with an A / B ratio above 1.3, such as golf carts (A / B=1.5), electric carts (A / B=2.0-2.4), and forklifts (A / B=2.4).

[0004] Also, as shown in FIG. 8, there is a method for suppressing the twisting phenomenon of a tire by mounting a rubber foam ring 2 on the upper side and a rubber or resin molded ring 3 on the lower side in a cavity inside a tire component 1 with them in contact with each other (Patent Document 4), but this does not aim to improve the ease of assembly when mounting the rubber foam ring 2. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-210930 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-111378 [Patent Document 3] Japanese Unexamined Patent Publication No. 52-49503 [Patent Document 4] Japanese Patent Application Publication No. 9-2014 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a puncture-proof tire with improved assembly ease and riding comfort. [Means for solving the problem]

[0007] In order to achieve the above object, the puncture-proof tire of the present invention is a puncture-proof tire (10) having a cavity (12) inside a cross section of a tire member (11) (without discontinuities in the annular direction), A first member (13) made of extruded sponge rubber is attached in an annular shape to the outer side of the cavity (12) which is the contact surface side of the tire member (11), and a second member (14) formed in an annular shape is attached to the inner side of the cavity (12), thereby dividing the tire member (11) into two parts. The first member (13) and the second member (14) are arranged so as to be in contact with each other near the center between the outward side and the inward side of the cavity (12).

[0008] In addition, the present invention is characterized in that the area ratio of the first member (13) to the entire cross-sectional shape of the tire member (11) is 30 to 70%.

[0009] The present invention is also characterized in that the relationship between the outer diameter A and the inner diameter B of the tire member (11) is A / B≧1.3.

[0010] The present invention is also characterized in that the first member (13) and the second member (14) are in contact with each other by fitting a recess (15) or protrusion formed on the first member (13) into a protrusion (16) or recess formed on the second member (14).

[0011] Furthermore, the present invention is characterized in that a hollow portion (17) is formed in the center of the second member (14).

[0012] The present invention is also characterized in that a gap (18) is formed between the first member (13) and the second member (14).

[0013] It should be noted that symbols in parentheses indicate corresponding elements or matters described in the drawings and in the detailed description to be described later. [Effects of the Invention]

[0014] According to the present invention, a first component made of extruded sponge rubber is attached in an annular shape to the outward side of a cavity that forms the contact surface side of the tire component. This provides superior cushioning and ride comfort compared to tires in which urethane resin or epoxy resin is injected into the tire and hardened, or tires in which the entire tire is molded in a mold. Not only does sponge rubber have the elasticity and flexibility due to the bubbles, but its processing method (extrusion molding) allows the extruded cross-sectional shape to be freely shaped to provide excellent cushioning properties. In addition, the first member set on the contact surface side and the second member set on the rim member side are arranged in the cavity of the tire component so that they are in contact near the center between the outward and inward sides of the cavity, so the first member and the second member can be installed separately. This means that workers do not need to apply a large amount of force during assembly, making it easy to assemble.

[0015] Furthermore, according to the present invention, the area ratio of the first member to the cross-sectional shape of the tire member is 30 to 70% of the whole. Therefore, unlike the conventional example (Patent Document 4) in which the rubber foam ring 2 occupies most of the cavity of the tire member, the first member and the second member each occupy about half of the cavity of the tire member. Therefore, by dividing the first member and the second member in half, they can be attached without much force.

[0016] This technology is particularly effective for vehicles where the relationship between the outer diameter A and the inner diameter B of the tire components is A / B≧1.3, such as wheelchairs, and for vehicles where A / B≧1.5, such as golf carts, electric carts, and forklifts, because it improves both ease of assembly and ride comfort. It is also particularly effective for vehicles where A / B≧2.0, such as electric carts and forklifts.

[0017] Furthermore, according to the present invention, the first member and the second member are configured such that the convex portion formed on the second member fits into the concave portion formed on the first member, or the concave portion formed on the second member fits into the convex portion formed on the first member, thereby preventing the first member and the second member from becoming misaligned in the cavity of the tire member.

[0018] Furthermore, according to the present invention, a hollow portion is formed in the center of the second member, or a gap is formed between the first member and the second member, thereby providing better cushioning properties. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is an external side view showing a puncture-proof tire according to an embodiment of the present invention. [Figure 2] 2 is an enlarged cross-sectional view taken along line XX in FIG. 1, showing a puncture-proof tire according to an embodiment of the present invention. [Figure 3] 3(a) is a perspective view showing a state before the first member shown in FIG. 2 is attached, and FIG. 3(b) is a perspective view showing a state before the second member shown in FIG. 2 is attached. [Figure 4]2 is an enlarged cross-sectional view taken along line XX in FIG. 1, showing another puncture-proof tire according to an embodiment of the present invention. FIG. [Figure 5] 2 is an enlarged cross-sectional view taken along line XX in FIG. 1, showing another puncture-proof tire according to an embodiment of the present invention. FIG. [Figure 6] 2 is an enlarged cross-sectional view taken along line XX in FIG. 1, showing another puncture-proof tire according to an embodiment of the present invention. FIG. [Figure 7] FIG. 2 is an external side view showing the size of the tire. [Figure 8] FIG. 1 is a cross-sectional view showing a conventional puncture-proof tire. DETAILED DESCRIPTION OF THE INVENTION

[0020] A puncture-proof tire according to an embodiment of the present invention will be described with reference to FIGS. This puncture-proof tire 10 is shown as an example applied to a tire of an electric cart (including a handle-type electric wheelchair).

[0021] As shown in FIG. 1, the A / B value, which indicates the relationship between the tire's outer diameter A (strictly speaking, the value obtained by subtracting the thickness of the tire's outer shell) and its inner diameter B, is 2.4. As shown in the cross section in FIG. 2, a first member 13 and a second member 14 are attached in a divided state to a cavity 12 formed inside a tire member 11 (without any gaps in the annular direction).

[0022] The first member 13 is attached to the outward side (upper side in Figure 2) of the cavity 12 that faces the contact surface of the tire member 11, and the second member 14 is attached to the inward side (lower side in Figure 2) of the cavity 12 that faces the rim member 20.

[0023] As shown in Fig. 3, the first member 13 is made of extruded sponge rubber and attached in a ring shape, and the second member 14 is also made of extruded sponge rubber and attached in a ring shape. The ends of the first member 13 and the second member 14 are butted together to form a ring shape, but the butting portions 13a, 14a may be bonded with an adhesive or may not be bonded at all. The butting portions 13a of the first member 13 and the butting portions 14a of the second member 14 are not in the same position as shown in Fig. 1, but are positioned 180 degrees apart in this example.

[0024] A recess 15 is formed in the center of the inward side (second member 14 side) of the first member 13, and a protrusion 16 is formed in the center of the outward side (first member 13 side) of the second member 14. As shown in FIG. 2, the first member 13 and the second member 14 are attached to the cavity 12 such that the recess 15 of the first member 13 fits into the protrusion 16 of the second member 14. The recess 15 of the first member 13 fits into the protrusion 16 of the second member 14, preventing the first member 13 and the second member 14 from shifting positions in the cavity 12 of the tire member 11. Note that a protrusion may be provided on the first member 13 side and a recess may be provided on the second member 14 side, and the two may be fitted together.

[0025] At this time, the first member 13 and the second member 14 are arranged so as to contact each other near the center portion between the outward side and the inward side of the cavity 12 . Here, the vicinity of the central portion between the outward side and the inward side of the cavity 12 specifically refers to a position that is within 15(%) above and below the halfway point CL when the vertical distance of the cavity 12 is 100(%), as shown in Figure 2.

[0026] In addition, in the cross-sectional shape of the tire member 11, the area ratio of the first member 13 to the entire area (area occupied by the cavity 12) is 30 to 70%, and conversely, the area ratio of the second member 14 to the entire area is 70 to 30%. Furthermore, the first member 13 has a specific gravity of 0.5 to 0.85 and an Asker C hardness of 40 to 75, and the second member 14 has a specific gravity of 0.45 to 0.80 and an Asker C hardness of 25 to 65. The tire member 11 has a type A durometer hardness of 70 (in accordance with JIS K6253) (however, wires and net-like fibers (not shown) are inserted inside).

[0027] Furthermore, a hollow portion 17 is formed in the center of the second member 14 to further enhance cushioning. The hollow portion 17 has an elliptical shape extending vertically, but is not limited to this, and may have a shape extending horizontally (approximately chestnut-shaped) as shown in Fig. 4.

[0028] Furthermore, the hollow portion 17 can be provided on the first member 13 side instead of the second member 14 side, and as shown in Figures 5 and 6, a gap 18 can be formed between the first member 13 and the second member 14 to improve cushioning. In the case of Figure 5, the gap 18 extends in the left-right direction, and in the case of Figure 6, it extends in the up-down direction, and the shape of these gaps 18 is not particularly limited.

[0029] According to the puncture-proof tire 10 configured as described above, the first member 13 made of extruded sponge rubber is attached in a ring shape to the outward side of the cavity 12 of the tire member 11, so compared to conventional examples in which urethane resin or epoxy resin is injected into the tire and hardened, or tires in which the entire tire is molded in a mold, the tire has excellent cushioning properties and ride comfort. Furthermore, since the first member 13 and the second member 14 are arranged in the cavity 12 of the tire member 11 so as to contact near the center portion between the outward side and the inward side of the cavity 12, the first member 13 and the second member 14 can be attached in a separated state. This eliminates the need for a worker to apply a large force during assembly, and allows the first member 13 and the second member 14 to be easily assembled into the cavity 12.

[0030] Furthermore, in the cross-sectional shape of the tire member 11, the area ratio of the first member 13 to the whole is 30 to 70%. Therefore, unlike the conventional example (Patent Document 4) in which the rubber foam ring 2 occupies most of the cavity of the tire member, the first member 13 and the second member 14 each occupy about half of the cavity 12 of the tire member 11. Therefore, by dividing the first member 13 and the second member 14 in half, they can be attached easily without requiring a great deal of force.

[0031] In this embodiment, both the first member 13 and the second member 14 are made of extruded sponge rubber and are attached in a ring shape to the cavity 11 of the tire member 10. The first member 13 is made of extruded sponge rubber, but the second member 14 can also be made by injecting urethane resin or epoxy resin into the tire and hardening it.

[0032] In this embodiment, the example is described in which the tire is applied to an electric cart with an A / B ratio of 2.4, but the A / B ratio of tires for vehicles called electric carts (including electric wheelchairs with handlebars) is generally 2.0 to 2.5, and the tire can also be applied to these vehicles. Furthermore, in addition to forklifts (A / B=2.4), the tire can also be applied to bicycles (A / B=1.2), wheelchairs (A / B=1.3), and golf carts (A / B=1.5), which have smaller A / B ratios. In particular, it is effective in vehicle tires with A / B≧1.3, since it can improve both the ease of assembly and the riding comfort. [Explanation of symbols]

[0033] 1 Tire components 2. Rubber foam ring 3. Resin molded ring body 10. Puncture-proof tires 11 Tire components 12 Cavity 13 First member 13a Stopping part 14 Second member 14a Stop part 15 recess 16 Convex part 17 Hollow part 18 Gap 20 Rim member

Claims

1. A puncture-proof tire having a cavity inside a tire member, a first member made of extruded sponge rubber and having an annular shape is attached to the outer side of the cavity, which is the contact surface side of the tire member, and a second member formed in an annular shape is attached to the inner side of the cavity, thereby dividing the tire member into two parts; A puncture-proof tire characterized in that the first member and the second member are arranged so as to be in contact with each other near a central portion between the outward side and the inward side of the cavity.

2. 2. The puncture-proof tire according to claim 1, wherein the area ratio of the first member to the cross-sectional shape of the tire member is 30 to 70% of the entire tire member.

3. 3. The puncture-proof tire according to claim 1, wherein the relationship between the outer diameter A and the inner diameter B of the tire member is A / B≧1.

3.

4. 2. The puncture-proof tire according to claim 1, wherein the first member and the second member are in contact with each other by fitting a convex or concave portion formed on the second member into a concave or convex portion formed on the first member.

5. 3. The puncture-proof tire according to claim 1, wherein a hollow portion is formed in the center of the second member.

6. 3. The puncture-proof tire according to claim 1, wherein a gap is formed between the first member and the second member.

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