pneumatic tires

Abstract

This invention provides a pneumatic tire that allows for efficient puncture repair using puncture repair fluid, eliminates the need for tire replacement after puncture repair, and improves the durability of the sound-absorbing material. [Solution] The present invention relates to a pneumatic tire 1 in which a sound-absorbing body 3 is detachably attached to the inner surface 2a of the tread portion 2. The sound-absorbing body 3 is formed in an annular shape by joining a main body portion 4 made of a long sponge material. The main body portion 4 has a joint surface 4c where a first end 4a on one side in the longitudinal direction and a second end 4b on the other side are joined. The joint surface 4c is inclined with respect to the radial direction of the tire. The length of the outer circumferential surface 3a of the sound-absorbing body 3 is smaller than the length of the inner surface 2a of the tread portion 2.

Description

Technical Field

[0001] The present invention relates to a pneumatic tire with a sound absorber attached to its inner cavity surface.

Background Art

[0002] Conventionally, a pneumatic tire with a sound absorber attached to the inner surface of the tread portion is known. For example, Patent Document 1 below proposes a pneumatic tire that achieves both improved puncture repair efficiency and noise performance by forming grooves on the outer peripheral surface of a sponge-like sound absorber fixed to the inner surface of the tread portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, even in the pneumatic tire of Patent Document 1, when a puncture repair liquid is used, the puncture repair liquid is partially absorbed by the sponge-like sound absorber, resulting in an unstable weight balance in the tire circumferential direction and vibrations may occur during driving. Therefore, even if a pneumatic tire with a sound absorber fixed thereto can be repaired to a temporarily drivable state by puncture repair using a puncture repair liquid, tire replacement has been required thereafter.

[0005] The present invention has been devised in view of the above actual situation, and its main object is to provide a pneumatic tire that can efficiently perform puncture repair using a puncture repair liquid, does not require tire replacement after puncture repair, and can improve the durability performance of the sound absorber.

Means for Solving the Problems

[0006] The present invention relates to a pneumatic tire in which a sound-absorbing material is detachably attached to the inner surface of the tread portion, wherein the sound-absorbing material is formed in an annular shape by joining a main body made of a long sponge material, the main body has a joint surface where a first end on one longitudinal side and a second end on the other longitudinal side are joined, the joint surface is inclined with respect to the radial direction of the tire, and the length of the outer surface of the sound-absorbing material is smaller than the length of the inner surface of the tread portion. [Effects of the Invention]

[0007] The pneumatic tire of the present invention, having the above-described configuration, allows for efficient puncture repair using puncture repair fluid, eliminates the need to replace the tire after puncture repair, and improves the durability of the sound-absorbing material. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing one embodiment of the pneumatic tire of the present invention. [Figure 2] This is a schematic diagram of the disassembled end face of a pneumatic tire. [Figure 3] This is a schematic diagram of a meridian cross-section of a pneumatic tire. [Figure 4] This is a magnified section of Figure 1. [Figure 5] This is a schematic diagram showing the tread section viewed from the inner side. [Modes for carrying out the invention]

[0009] One embodiment of the present invention will be described in detail below with reference to the drawings. Figure 1 is a schematic cross-sectional view perpendicular to the tire axis direction showing the pneumatic tire 1 of this embodiment in contact with the road surface R. As shown in Figure 1, the pneumatic tire 1 of this embodiment has a sound-absorbing body 3 detachably attached to the inner surface 2a of the tread portion 2.

[0010] In other words, the sound-absorbing body 3 in this embodiment is positioned on the inner surface 2a of the tread portion 2 without being fixed in place. With such a sound-absorbing body 3, even if the puncture repair fluid is partially absorbed when a puncture is repaired using puncture repair fluid, causing an unstable weight balance in the circumferential direction of the tire, only the sound-absorbing body 3 can be replaced, eliminating the need to replace the tire after the puncture repair.

[0011] The pneumatic tire 1 is preferably used, for example, as a passenger car tire. The pneumatic tire 1 is not limited to this embodiment and can be applied to various types of tires, such as heavy-duty tires, light cargo tires, off-road tires, electric vehicle tires, and industrial machinery tires.

[0012] In this embodiment, the sound-absorbing body 3 is formed in an annular shape by joining together a main body portion 4 made of elongated sponge material. Compared to sound-absorbing bodies that are molded in an annular shape, this type of sound-absorbing body 3 can reduce manufacturing costs and can easily be produced in multiple sizes.

[0013] The main body 4 preferably has a joint surface 4c where a first end 4a on one longitudinal side and a second end 4b on the other side are joined. In this embodiment, the joint surface 4c is inclined with respect to the tire radial direction. Such a joint surface 4c can secure a large joining area and can distribute the stress acting on the joint surface 4c during compression deformation, thereby improving the durability of the sound absorber 3.

[0014] Figure 2 is a schematic diagram of the exploded end face of a pneumatic tire 1 at the tire equator C. As shown in Figures 1 and 2, it is desirable that the length L1 of the outer surface 3a of the sound absorber 3 is smaller than the length L2 of the inner surface 2a of the tread portion 2. Such a sound absorber 3 has a main body 4 made of sponge material with a specific gravity lower than the specific gravity of the puncture repair fluid, and also has dimensional clearance relative to the inner surface 2a of the tread portion 2, making it easy to float the main body 4 in the puncture repair fluid during puncture repair.

[0015] Therefore, the pneumatic tire 1 of this embodiment allows the puncture repair fluid to be smoothly moved to the puncture site when a puncture is repaired using puncture repair fluid, enabling efficient puncture repair. As a result, the pneumatic tire 1 of this embodiment allows for efficient puncture repair using puncture repair fluid, eliminating the need to replace the tire after the puncture repair and improving the durability of the sound-absorbing material 3.

[0016] In a more preferred embodiment, the length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 is 98% or less of the length L2 of the inner surface 2a of the tread portion 2. By having the length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 be 98% or less of the length L2 of the inner surface 2a of the tread portion 2, a dimensional margin relative to the inner surface 2a of the tread portion 2 can be reliably secured, which is useful for efficient puncture repair using puncture repair fluid. From this viewpoint, the length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 is more preferably 97% or less of the length L2 of the inner surface 2a of the tread portion 2, and even more preferably 95% or less.

[0017] The length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 is preferably 85% or more of the length L2 of the inner surface 2a of the tread portion 2. By having the length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 be 85% or more of the length L2 of the inner surface 2a of the tread portion 2, wear between the outer circumferential surface 3a of the sound-absorbing body 3 and the inner surface 2a of the tread portion 2 can be suppressed, and the durability of the sound-absorbing body 3 can be improved. From this viewpoint, the length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 is more preferably 88% or more of the length L2 of the inner surface 2a of the tread portion 2, and even more preferably 90% or more.

[0018] Based on these considerations, the length L1 of the outer circumferential surface 3a of the sound-absorbing body 3 is preferably 85% to 98% of the length L2 of the inner surface 2a of the tread portion 2, more preferably 88% to 97%, and even more preferably 90% to 95%. The combination of the upper and lower limits within these numerical ranges can be arbitrarily selected.

[0019] FIG. 3 is a schematic cross-sectional view of a pneumatic tire 1 including a tire axis. As shown in FIGS. 1 and 3, the sound absorber 3 includes at least one, in this embodiment, one main body portion 4. The sound absorber 3 is not limited to such a mode. For example, it may include a plurality of main body portions 4 divided in the tire circumferential direction, and the plurality of main body portions 4 may be arranged in parallel in the tire axis direction.

[0020] The main body portion 4 has at least one, in this embodiment, one joint surface 4c. The main body portion 4 is not limited to such a mode. For example, it may have a plurality of joint surfaces 4c formed by a plurality of main body portions 4.

[0021] The cross-sectional shape of the main body portion 4 is, for example, rectangular. Such a main body portion 4 is easy to manufacture and can reduce the manufacturing cost. The main body portion 4 is not limited to such a mode. For example, it may have at least one groove (not shown) or concavo-convex structure on the outer peripheral surface 3a side or the inner peripheral surface 3b side of the sound absorber 3. The groove may extend in the tire circumferential direction, may extend in the tire axis direction, or may extend in a direction inclined with respect to the tire circumferential direction.

[0022] The maximum cross-sectional thickness t of the main body portion 4 in the tire radial direction is preferably 10 mm or more. By having the maximum cross-sectional thickness t of the main body portion 4 be 10 mm or more, the noise performance of the pneumatic tire 1 can be surely improved. From such a viewpoint, the maximum cross-sectional thickness t of the main body portion 4 is more preferably 15 mm or more, and still more preferably, 20 mm or more.

[0023] The maximum cross-sectional thickness t of the main body portion 4 in the tire radial direction is preferably 40 mm or less. By having the maximum cross-sectional thickness t of the main body portion 4 be 40 mm or less, the excellent handling stability performance, riding comfort performance, and low fuel consumption performance of the pneumatic tire 1 can be maintained. From such a viewpoint, the maximum cross-sectional thickness t of the main body portion 4 is more preferably 35 mm or less, and still more preferably, 30 mm or less.

[0024] Based on these considerations, the maximum cross-sectional thickness t of the main body 4 in the tire radial direction is preferably 10 to 40 mm, more preferably 15 to 35 mm, and even more preferably 20 to 30 mm. The combination of the upper and lower limits within these numerical ranges can be arbitrarily selected.

[0025] The maximum cross-sectional width w of the main body 4 in the tire axial direction is preferably 20% or more of the maximum cross-sectional width WS of the pneumatic tire 1. By having the maximum cross-sectional width w of the main body 4 be 20% or more of the maximum cross-sectional width WS of the pneumatic tire 1, the noise performance of the pneumatic tire 1 can be reliably improved. From this viewpoint, the maximum cross-sectional width w of the main body 4 is more preferably 30% or more of the maximum cross-sectional width WS of the pneumatic tire 1, and even more preferably 40% or more.

[0026] The maximum cross-sectional width w of the main body 4 in the tire axial direction is preferably 80% or less of the maximum cross-sectional width WS of the pneumatic tire 1. By keeping the maximum cross-sectional width w of the main body 4 at 80% or less of the maximum cross-sectional width WS of the pneumatic tire 1, the excellent handling stability, ride comfort, and fuel efficiency of the pneumatic tire 1 can be maintained. From this viewpoint, the maximum cross-sectional width w of the main body 4 is more preferably 70% or less of the maximum cross-sectional width WS of the pneumatic tire 1, and even more preferably 60% or less.

[0027] Based on these considerations, the maximum cross-sectional width w of the main body 4 in the tire axial direction is preferably 20% to 80% of the maximum cross-sectional width WS of the pneumatic tire 1, more preferably 30% to 70%, and even more preferably 40% to 60%. The combination of the upper and lower limits within these numerical ranges can be arbitrarily selected.

[0028] The main body 4 is, for example, joined at the first end 4a and the second end 4b by adhesive. Such a main body 4 has high adhesive strength at the joint surface 4c, which can improve the durability of the sound absorber 3. Furthermore, such a main body 4 is easy to manufacture and offers excellent cost performance.

[0029] The main body 4 may, for example, have its first end 4a and second end 4b joined by welding. In such a main body 4, the movement of puncture repair fluid is smooth at the joint surface 4c, allowing for efficient puncture repair using the puncture repair fluid. Furthermore, in such a main body 4, the weight fluctuation at the joint surface 4c is small, resulting in excellent weight balance in the circumferential direction of the tire, and vibrations during driving can be suppressed.

[0030] Figure 4 is a partially enlarged view of Figure 1. As shown in Figure 4, the angle θ1 of the joint surface 4c with respect to the tire radial direction is preferably 5° or more. An angle θ1 of 5° or more of the joint surface 4c with respect to the tire radial direction ensures that stress during compressive deformation is reliably distributed. From this viewpoint, the angle θ1 of the joint surface 4c with respect to the tire radial direction is more preferably 15° or more, and even more preferably 30° or more.

[0031] The angle θ1 of the joint surface 4c with respect to the tire radius is preferably 60° or less. By having an angle θ1 of the joint surface 4c with respect to the tire radius of 60° or less, the outer end 4d of the joint surface 4c in the tire radius direction does not become excessively acute, and damage originating from the outer end 4d due to contact with the inner surface 2a of the pneumatic tire 1 can be suppressed. From this viewpoint, the angle θ1 of the joint surface 4c with respect to the tire radius of 55° or less is more preferably 50° or less.

[0032] Based on these considerations, the angle θ1 of the joint surface 4c with respect to the tire radius is preferably 5 to 60°, more preferably 15 to 55°, and even more preferably 30 to 50°. The combination of the upper and lower limits within these numerical ranges can be arbitrarily selected.

[0033] Figure 5 is a schematic diagram of the tread portion 2 as viewed from the inner surface 2a side. As shown in Figure 5, the joint surface 4c is inclined, for example, with respect to the tire axis. Such a joint surface 4c can secure a large joint area and can also distribute the stress acting in the longitudinal direction of the main body portion 4, thereby improving the durability of the sound absorber 3.

[0034] The angle θ2 of the joint surface 4c with respect to the tire axis is preferably 5° or more. By having an angle θ2 of 5° or more of the joint surface 4c with respect to the tire axis, the stress acting in the longitudinal direction of the main body 4 can be reliably distributed. From this viewpoint, the angle θ2 of the joint surface 4c with respect to the tire axis is more preferably 15° or more, and even more preferably 30° or more.

[0035] The angle θ2 of the joint surface 4c with respect to the tire axis is preferably 60° or less. By keeping the angle θ2 of the joint surface 4c with respect to the tire axis at 60° or less, it is possible to suppress the joint surface 4c from becoming excessively large and reduce manufacturing costs.

[0036] Based on these considerations, the angle θ2 of the joint surface 4c with respect to the tire axis is preferably 5 to 60°, more preferably 15 to 55°, and even more preferably 30 to 50°. The combination of the upper and lower limits within these numerical ranges can be arbitrarily selected.

[0037] As shown in Figures 1 to 5, the sound absorber 3 of this embodiment has a specified mounting direction r2 with respect to the rotation direction r1 of the pneumatic tire 1. Such a sound absorber 3 can adopt a shape that corresponds to the influence based on the rotation direction r1 of the pneumatic tire 1.

[0038] In this embodiment, the sound-absorbing body 3 is installed so that the outer end 4d of the joint surface 4c in the tire radial direction is the first to be attached. Even if there is a difference between the rotational speed of the pneumatic tire 1 and the rotational speed of the sound-absorbing body 3, such a sound-absorbing body 3 can suppress damage starting from the outer end 4d of the joint surface 4c and improve durability.

[0039] It is preferable that the sound-absorbing body 3 has a display section 5 on its inner circumferential surface 3b that indicates the mounting direction r2. In this embodiment, the display section 5 is an arrow indicating the mounting direction r2. Such a sound-absorbing body 3 has excellent visibility and can suppress mounting errors. Note that the display section 5 is not limited to this form, and for example, an arrow may be displayed along with words such as "tire rotation direction" or "directional".

[0040] Although particularly preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above and can be implemented in various modified forms.

[0041] [Note] The present invention is as follows:

[0042] [Invention 1] A pneumatic tire in which a sound-absorbing material is detachably attached to the inner surface of the tread, The sound-absorbing body is formed in an annular shape by joining together main body parts made of elongated sponge material. The main body has a joint surface where a first end on one side in the longitudinal direction and a second end on the other side are joined together. The aforementioned joining surface is inclined with respect to the tire radial direction, The length of the outer surface of the sound-absorbing material is smaller than the length of the inner surface of the tread portion. Pneumatic tires.

[0043] [Invention 2] The pneumatic tire according to claim 1, wherein the length of the outer surface of the sound-absorbing body is 98% or less of the length of the inner surface of the tread portion.

[0044] [Invention 3] The pneumatic tire according to invention 1 or 2, wherein the angle of the joint surface with respect to the tire radial direction is 5 to 60°.

[0045] [4th Invention] The aforementioned joint surface is inclined with respect to the tire axis, as described in any one of inventions 1 to 3.

[0046] [5th ​​Invention] The pneumatic tire according to the present invention, wherein the angle of the joint surface with respect to the tire axis is 5 to 60°.

[0047] [Invention 6] The main body is a pneumatic tire according to any one of inventions 1 to 5, wherein the first end and the second end are joined together by an adhesive.

[0048] [7th Invention] The main body portion is a pneumatic tire according to any one of inventions 1 to 5, wherein the first end and the second end are joined by welding.

[0049] [8th Invention] The sound-absorbing material is specified in a mounting direction relative to the rotation direction of the pneumatic tire, as described in any one of invention 1 to 7.

[0050] [Invention 9] The pneumatic tire according to the present invention, wherein the sound-absorbing material is mounted such that the outer end of the joint surface in the radial direction of the tire is the first to be attached.

[0051] [Invention 10] The sound-absorbing material has a display portion on its inner circumferential surface indicating the mounting direction, as described in the pneumatic tire according to the present invention 8 or 9. [Explanation of Symbols]

[0052] 1. Pneumatic tire 2 Tread section 2a Inner surface 3. Sound absorber 3a Outer surface 4. Main body 4a 1st end 4b 2nd end 4c Joint surface

Claims

1. A pneumatic tire in which a sound-absorbing material is detachably attached to the inner surface of the tread, The sound-absorbing body is formed in an annular shape by joining together main body parts made of elongated sponge material. The main body has a joining surface where a first end on one longitudinal side and a second end on the other side are joined together. The aforementioned joining surface is inclined with respect to the tire radial direction, The length of the outer surface of the sound-absorbing material is smaller than the length of the inner surface of the tread portion. Pneumatic tires.

2. The pneumatic tire according to claim 1, wherein the length of the outer surface of the sound-absorbing body is 98% or less of the length of the inner surface of the tread portion.

3. The pneumatic tire according to claim 1, wherein the angle of the joint surface with respect to the tire radius direction is 5 to 60°.

4. The pneumatic tire according to claim 3, wherein the joining surface is inclined with respect to the tire axis.

5. The pneumatic tire according to claim 4, wherein the angle of the joint surface with respect to the tire axis is 5 to 60°.

6. The pneumatic tire according to any one of claims 1 to 5, wherein the main body portion is joined at the first end and the second end by an adhesive.

7. The pneumatic tire according to any one of claims 1 to 5, wherein the main body portion is joined at the first end and the second end by welding.

8. The pneumatic tire according to any one of claims 1 to 5, wherein the sound-absorbing element has a mounting direction specified relative to the rotation direction of the pneumatic tire.

9. The pneumatic tire according to claim 8, wherein the sound-absorbing material is mounted such that the outer end of the joint surface in the radial direction of the tire is the first to be attached.

10. The pneumatic tire according to claim 8, wherein the sound-absorbing material has a display portion on its inner circumferential surface indicating the mounting direction.

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