Pneumatic tire

Abstract

To provide a pneumatic tire which comprises an acoustic absorbent, nevertheless enables a puncture repair agent to be properly permeated to the necessary portion of the tire.SOLUTION: A tire 1 is provided with an acoustic absorbent 60 provided on a tire inner surface 501 and joining materials 70 joining the tire inner surface 501 to the acoustic absorbent 60. Space portions (71 and 72) where the jointing materials 70 are not provided are provided on a position where the tire inner surface 501 is opposing to the acoustic agent 60. The space portions (71 and 72) are communicated with a tire inner cavity space LS formed closer to inside in a tire radial direction than the acoustic absorbent 60.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to pneumatic tires.

Background Art

[0002] Conventionally, a pneumatic tire is known in which a sound-absorbing material made of a porous sponge material or the like is disposed on the inner surface of the tire to reduce cavity resonance generated in the tire cavity and reduce in-vehicle noise (see, for example, Patent Document 1).

[0003] In the pneumatic tire of Patent Document 1, peeling of the sound-absorbing material is suppressed by providing an adhesive region and a non-adhesive region for adhesion between the sound-absorbing material and the inner surface of the tire.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the pneumatic tire described in Patent Document 1, most of the regions other than the partially provided non-adhesive region are adhesive regions where the sound-absorbing material and the inner surface of the tire are adhered. Therefore, there are many regions where the sound-absorbing material and the adhesive are in close contact with the inner surface of the tire, and when a puncture repair agent is used, there is a high possibility that the puncture repair agent cannot properly penetrate into the required parts.

[0006] An object of the present disclosure is to provide a pneumatic tire in which a puncture repair agent can easily penetrate even when a sound-absorbing material is provided.

Means for Solving the Problems

[0007] The pneumatic tire of the present disclosure includes a sound-absorbing material provided on the inner surface of the tire and an adhesive for joining the inner surface of the tire and the sound-absorbing material. A space portion where the adhesive is not provided is provided at a position where the inner surface of the tire and the sound-absorbing material face each other, and the space portion communicates with the inner cavity space of the tire radially inward of the sound-absorbing material.

Advantages of the Invention

[0008] According to the present disclosure, it is possible to provide a pneumatic tire in which a puncture repair agent can easily penetrate appropriately even when a sound-absorbing material is provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0010] Hereinafter, an embodiment for carrying out the present disclosure will be described with reference to the drawings and the like.

[0011] (Embodiment) FIG. 1 is a cross-sectional view in the tire axial direction of a pneumatic tire 1 according to an embodiment of the present disclosure. FIG. 2 is a perspective view showing a state in which the tire 1 of the embodiment is cut in the tire axial direction (tire meridian). Note that each of the figures shown below, including FIG. 1, is a schematic figure, and the size and shape of each part are exaggerated or omitted as appropriate for easy understanding. In the following description, specific numerical values, shapes, materials, etc. are shown for explanation, but these can be changed as appropriate.

[0012] The tire 1 is, for example, a tire for a passenger car. The basic structure of the tire 1 is symmetric about the cross-section in the tire axial direction (tire width direction). In the figure, reference sign S1 is the tire equatorial plane. The tire equatorial plane S1 is a plane orthogonal to the tire rotation axis (tire meridian) and located at the center in the tire axial direction.

[0013] Note that the cross-sectional view of FIG. 1 is a cross-sectional view in the tire axial direction (tire meridian cross-sectional view) of the tire in the unloaded state in which the tire 1 is mounted on a specified rim and filled with a specified internal pressure. The specified rim refers to the standard rim defined by JATMA corresponding to the tire size. The specified internal pressure is, for example, 180 kPa when the tire is for a passenger car.

[0014] Here, the tire axial direction is a direction parallel to the tire rotation axis and is the left-right direction of the paper surface in the cross-sectional view of FIG. 1. In FIG. 1, it is illustrated as the tire axial direction X. And the inner side in the tire axial direction is the direction approaching the tire equatorial plane S1, and in FIG. 1, it is the center side of the paper surface. The outer side in the tire axial direction is the direction away from the tire equatorial plane S1, and in FIG. 1, it is the left side and the right side of the paper surface.

[0015] Also, the tire radial direction is a direction perpendicular to the tire rotation axis and is the up-down direction of the paper surface in FIG. 1. In FIG. 1, it is illustrated as the tire radial direction Y. And the outer side in the tire radial direction is the direction away from the tire rotation axis, and in FIG. 1, it is the lower side of the paper surface. The inner side in the tire radial direction is the direction approaching the tire rotation axis, and in FIG. 1, it is the upper side of the paper surface.

[0016] As shown in FIG. 1, the tire 1 includes a pair of beads 10 provided on both sides in the tire axial direction, a pair of sidewalls 20 extending radially outward in the tire diameter direction from each of the pair of beads 10, a tread 30 disposed between the pair of sidewalls 20, a carcass ply 40 disposed between the pair of beads 10, and an inner liner 50 disposed on the tire inner cavity side of the carcass ply 40.

[0017] The bead 10 includes a bead core 11, a bead filler 12 extending radially outward in the tire diameter direction from the bead core 11, a chafer 13, and a rim strip rubber 14.

[0018] The bead core 11 is an annular member formed by winding a plurality of rubber-coated metal bead wires, and is a member that serves to fix the air-filled tire 1 to the rim.

[0019] The bead filler 12 is a rubber member having a tapered shape as it extends radially outward in the tire diameter direction. The bead filler 12 is a member provided to increase the rigidity of the peripheral portion of the bead 10 and ensure high maneuverability and stability. The bead filler 12 is composed of, for example, rubber having a higher hardness than the surrounding rubber members.

[0020] The chafer 13 is provided on the inner side in the tire diameter direction of the carcass ply 40 provided around the bead core 11.

[0021] The rim strip rubber 14 is disposed on the outer side in the tire axial direction of the chafer 13 and the carcass ply 40. The rim strip rubber 14 is a member that contacts the rim on which the tire 1 is mounted.

[0022] The sidewall 20 includes a sidewall rubber 21 disposed on the outer side in the tire axial direction of the carcass ply 40. The sidewall rubber 21 constitutes the outer wall surface of the tire 1. The sidewall rubber 21 is the most flexible part when the tire 1 acts as a cushion, and usually, a flexible rubber having fatigue resistance is adopted.

[0023] The tread 30 includes an endless belt 31 and a cap ply 32, and a tread rubber 33.

[0024] The belt 31 is disposed on the outer side in the tire radial direction of the carcass ply 40. The cap ply 32 is disposed on the outer side in the tire radial direction of the belt 31.

[0025] The belt 31 is a member for reinforcing the tread 30. The belt 31 of the present embodiment has a two-layer structure including an inner belt 311 and an outer belt 312. Both the inner belt 311 and the outer belt 312 have a structure in which a plurality of cords such as steel cords are covered with rubber. Note that the belt 31 is not limited to a two-layer structure, and may have a single-layer or a three-layer or more structure.

[0026] The cap ply 32 is a member for reinforcing the tread 30 together with the belt 31. The cap ply 32 has a structure in which a plurality of insulating organic fiber cords such as polyamide fibers are covered with rubber. By providing the cap ply 32, it is possible to improve durability and reduce road noise during running.

[0027] The tread rubber 33 is disposed on the outer side in the tire radial direction of the cap ply 32. The tread rubber 33 is a member that constitutes a tread surface 37 that contacts the road surface during running. The tread surface 37 of the tread rubber 33 is provided with a tread pattern 34 composed of, for example, a plurality of grooves. The tread pattern 34 has a plurality of main grooves 341 arranged in the tire axial direction. Each of the plurality of main grooves 341 extends along the tire circumferential direction.

[0028] The carcass ply 40 constitutes the ply that forms the framework of the tire 1. The carcass ply 40 is embedded in the tire 1 in such a manner that it passes between a pair of beads 10 through a pair of sidewalls 20 and a tread 30. The carcass ply 40 includes a plurality of carcass cords (not shown) that form the framework of the tire 1. The plurality of carcass cords extend, for example, in the tire axial direction and are arranged side by side in the tire circumferential direction. The carcass cords are composed of insulating organic fiber cords such as polyester and polyamide cords. The plurality of carcass cords are coated with rubber to form the carcass ply 40.

[0029] The carcass ply 40 has a ply main body portion 401 that extends from one bead core 11 to the other bead core 11 and extends between the tread 30 and the bead 10, a pair of bent portions 402 that are folded back by the bead core 11 from the ply main body portion 401, and a pair of folded-back portions 403 that extend radially outward of the tire from each of the bent portions 402. The ply main body portion 401, the bent portions 402, and the folded-back portions 403 surround the bead filler 12 and the bead core 11. The folded-back portion 403 of the portion radially outside the tire than the bead filler 12 is overlapped with the ply main body portion 401.

[0030] The carcass ply 40 of the present embodiment has a single-layer structure, but the carcass ply 40 is not limited to a single-layer structure and may have a two-layer or three-layer or more structure.

[0031] The chafer 13 of the bead 10 described above is provided so as to surround the radially inner end portion of the carcass ply 40 including the bent portion 402. Further, the rim strip rubber 14 is disposed on the outer side in the tire axial direction of the chafer 13 and the folded-back portion 403 of the carcass ply 40. The radially outer end portion of the rim strip rubber 14 is covered with the sidewall rubber 21 described above.

[0032] The inner liner 50 covers the inner surface of the ply body portion 401 of the carcass ply 40 and the inner surface of the chafer 13 of the pair of beads 10. The inner liner 50 is made of air-permeability-resistant rubber and prevents the air in the tire inner cavity from leaking to the outside. The inner surface of the inner liner 50 constitutes the tire inner surface 501 between the pair of beads 10.

[0033] As shown in FIG. 1, the tire 1 according to the present embodiment further includes a sound-absorbing material 60 and an adhesive material 70.

[0034] The sound-absorbing material 60 is joined to the tire inner surface 501 by the adhesive material 70. The sound-absorbing material 60 of the embodiment is a sponge having a large number of pores formed of a foaming material, and a foamed resin such as polyurethane foam is preferably used. The sound-absorbing material 60 is attached to the tire inner surface 501 in the tread 30 by the adhesive material 70. The sound-absorbing material 60 of the embodiment is arranged symmetrically with the tire equatorial plane S1 as the symmetric center plane.

[0035] As shown in FIG. 2, the sound-absorbing material 60 is provided annularly on the tire inner surface 501 by at least one member. The sound-absorbing material 60 may be configured annularly by two or more members divided in the tire circumferential direction. In the following description, an example in which the sound-absorbing material 60 is provided annularly on the tire inner surface 501 by one member will be described. The sound-absorbing material 60 absorbs various sounds generated in the inner cavity of the tire 1 during running to reduce noise. The sound-absorbing material 60 may be substantially rectangular parallelepiped-shaped in the free state, or may be curved in the free state in accordance with the curved shape of the tire inner surface 501. However, in order to facilitate the manufacture of the sound-absorbing material 60 and reduce the unit price, it is desirable that the sound-absorbing material 60 be substantially rectangular parallelepiped-shaped in the free state.

[0036] Further, the surface of the sound-absorbing material 60 facing the inner surface 501 of the tire (the surface on the outer side in the tire radial direction) is preferably a flat surface. Here, the flat surface includes a form that is curved along the curved shape of the inner surface 501 of the tire but does not include large uneven shapes on its surface (the surface on the outer side in the tire radial direction). Naturally, although there are unevennesses due to the pores provided in the sound-absorbing material 60 on the surface, even if there are such unevennesses due to the pores, it can be regarded as a flat surface. By the surface of the sound-absorbing material 60 facing the inner surface 501 of the tire being a flat surface, it is possible to prevent a change in the form of the space portion described later due to relative displacement with the bonding material 70, and the manufacturing can be facilitated.

[0037] From the viewpoint of weight balance in the tire 1, the density of the sound-absorbing material 60 is 60 kg / m 3 The following is preferable, and the density is 40 kg / m 3 The following is more preferable. Further, from the viewpoint of durability, the sound-absorbing material 60 preferably has a tensile strength of 30 kPa or more and a tear strength of 2.0 N / cm or more (JIS K 6400-5:2012).

[0038] The dimensions of the sound-absorbing material 60 are selected according to the dimensions of the tire 1 and the like. For example, the width, that is, the length in the tire axial direction in the state of being attached to the inner surface 501 of the tire, is preferably 80 mm or more and 110 mm or less, and the thickness, that is, the dimension in the tire radial direction, is preferably about 20 mm.

[0039] The bonding material 70 is partially provided between the tire inner surface 501 and the sound-absorbing material 60, and is bonded in a state where a space portion (circumferential direction space portion 71, axial direction space portion 72) is provided with a gap between the tire inner surface 501 and the sound-absorbing material 60. The bonding material 70 has a function as a structure (spacer) that supports the sound-absorbing material 60 on the tire inner surface 501 so that this space portion is maintained. As the bonding material 70, an adhesive may be used, or a double-sided adhesive tape may be used, but an adhesive for rubber or for tires is preferably used. The bonding material 70 that bonds the sound-absorbing material 60 to the tire inner surface 501 preferably has a tensile strength of 1.5 MPa or more from the viewpoints of adhesive strength and durability. The tensile strength in this case is a value measured by a test method based on "JIS K 6251:2017".

[0040] FIG. 3 is a schematic cross-sectional view of the tire 1 of the embodiment cut along the tire equatorial plane S1. FIG. 4 is a view of the inner surface of the tire 1 of the embodiment developed, and is a schematic view seen from the inner surface side of the state where the tire 1 is cut and developed at the cutting line A in FIG. 3. In FIG. 4, the tire axial direction is indicated by the arrow X, and the tire circumferential direction is indicated by the arrow Z.

[0041] As shown in FIGS. 3 and 4, the bonding material 70 is formed by a plurality of strips of the bonding material 70 extending along the tire circumferential direction with respect to the tire inner surface 501 of the inner liner 50. The plurality of bonding materials 70 are arranged side by side at intervals in each of the tire axial direction and the tire circumferential direction.

[0042] In the present embodiment, four bonding materials 70 for bonding the sound-absorbing material 60 to the tire inner surface 501 are arranged in the tire axial direction, and a plurality of (four in the present embodiment) are arranged side by side at intervals in the tire circumferential direction. The four bonding materials 70 are arranged at equal intervals, two on each side centered on the tire equatorial plane S1, to bond the sound-absorbing material 60 and the tire inner surface 501. Note that the number of the bonding materials 70 is not limited to four, and can be appropriately changed depending on the width of the sound-absorbing material 60, the required adhesive strength, etc., but for example, 2 or more and 10 or less are preferable.

[0043] In the region where there are no adjacent bonding members 70 in the tire axial direction among the bonding members 70 arranged adjacent to each other in the tire axial direction, a circumferential space portion 71 extending in the tire circumferential direction is formed. The width (dimension in the tire axial direction) W71 of the circumferential space portion 71 in the tire axial direction is desirably 5 mm or more and 25 mm or less, but is not limited to this dimension. The reason for this will be described later. In addition, the above-mentioned dimension and other dimensions of the space portion described later are dimensions in a state where the adhesive has hardened when the bonding member 70 is an adhesive, and are dimensions in a no-load state where the tire 1 is mounted on a specified rim and filled with a specified internal pressure.

[0044] Moreover, each strip of the bonding member 70 has a plurality of them arranged side by side in the circumferential direction at intervals in the circumferential direction. For example, in the present embodiment, in one strip, the bonding members 70 are arranged with 4 of them side by side at an appropriate angle interval in the circumferential direction. Note that the number of the bonding members 70 arranged in the circumferential direction is not limited to 4, and can be appropriately changed according to the width of the sound-absorbing material 60, the required adhesive strength, etc., but for example, 2 or more and 10 or less are preferable.

[0045] In the region where there is no bonding member 70 between the bonding members 70 arranged side by side in the circumferential direction, an axial space portion 72 extending in the tire axial direction is formed. That is, the plurality of bonding members 70 are also arranged at intervals in the tire circumferential direction. The dimension W72 in the tire circumferential direction of the axial space portion 72 is desirably 5 mm or more and 25 mm or less, but is not limited to this dimension. The reason for this will be described later.

[0046] In addition, the circumferential space portion 71 and the axial space portion 72 communicate with each other. In the present embodiment, all the circumferential space portions 71 and the axial space portions 72 are in a communicating state. However, for example, there may be a space portion that does not communicate partially. Further, since the circumferential space portion 71 and the axial space portion 72 communicate with each other, the circumferential space portion 71 and the axial space portion 72 communicate with the tire inner cavity space LS on the inner side in the tire radial direction than the sound absorbing material 60. Thus, since the circumferential space portion 71 and the axial space portion 72 communicate with the tire inner cavity space LS, when a puncture repair agent is injected into the tire inner cavity space LS from a tire valve (not shown) in the tire 1 of the present embodiment, the puncture repair agent can directly touch the tire inner surface 501. Thereby, the possibility of being able to repair a puncture with the puncture repair agent can be dramatically increased.

[0047] Here, in addition to the circumferential space portion 71 and the axial space portion 72 being provided, the specific sizes of these circumferential space portion 71 and axial space portion 72 are important because they have a great influence on the penetrability of the puncture repair agent and the durability of the sound absorbing material 60.

[0048] The minimum distance h (see FIG. 1) in the tire radial direction between the surface of the sound absorbing material 60 facing the tire inner surface 501 and the tire inner surface 501 is desirably 1 mm or more and 10 mm or less. By having a distance (gap, space) of 1 mm or more between the sound absorbing material 60 and the tire inner surface 501, the puncture repair agent easily enters the circumferential space portion 71 and the axial space portion 72, and the puncture repair agent easily directly touches the tire inner surface 501. Therefore, the possibility of being able to repair a puncture with the puncture repair agent is increased. Further, when the above distance becomes larger than 10 mm, the possibility that the sound absorbing material 60 peels off from the tire inner surface 501 increases. Note that the minimum distance h in the tire radial direction is the distance at the portion where the distance is the shortest among the distances between the surface of the sound absorbing material 60 facing the tire inner surface 501 and the tire inner surface 501.

[0049] Also, as described above, the width (dimension in the tire axis direction) W71 of the circumferential space portion 71 in the tire axis direction is desirably 5 mm or more and 25 mm or less, and the dimension W72 of the axial space portion 72 in the tire circumferential direction is desirably 5 mm or more and 25 mm or less. When W71 and W72 are 5 mm or more, it becomes easier for the puncture repair agent to enter the circumferential space portion 71 and the axial space portion 72, and it becomes easier for the puncture repair agent to directly contact the tire inner surface 501. Further, when W71 and W72 are larger than 25 mm, the possibility that the sound absorbing material 60 peels off from the tire inner surface 501 increases.

[0050] The sound absorbing material 60 of the present embodiment is substantially rectangular parallelepiped-shaped in a free state, and one is arranged along the tire inner surface 501 with the ends 61 of the sound absorbing material 60 butted against each other in the circumferential direction at the butting portion 62. A bonding material 70 is provided between the butting portion 62 and the tire inner surface 501. That is, no axial space portion 72 is provided between the butting portion 62 and the tire inner surface 501. With this configuration, it is possible to suppress the peeling of the sound absorbing material 60 starting from the end 61 of the sound absorbing material 60, and the durability can be improved. Further, when it is desired to further enhance the durability, a form in which no space portion is provided between the butting portion 62 and the tire inner surface 501, that is, the bonding material 70 may be arranged between the butting portion 62 and the tire inner surface 501 without providing the circumferential space portion 71 and the axial space portion 72.

[0051] According to the tire 1 according to the present embodiment described above, the following effects are obtained.

[0052] (1) The tire 1 according to the present embodiment includes a sound absorbing material 60 provided on the tire inner surface 501 and a bonding material 70 that bonds the tire inner surface 501 and the sound absorbing material 60, and a space portion (71, 72) where the bonding material 70 is not provided is provided at a position where the tire inner surface 501 and the sound absorbing material 60 face each other, and the space portion (71, 72) communicates with the tire inner cavity space LS inside the tire in the tire radial direction more than the sound absorbing material 60.

[0053] As a result, even if the sound-absorbing material 60 is provided, the puncture repair agent can easily penetrate appropriately. More specifically, the puncture repair agent can flow into the inner surface 501 of the tire, penetrate appropriately into the damaged portion, and increase the possibility of successful puncture repair.

[0054] (2) In the pneumatic tire according to (1), the space portions (71, 72) include a circumferential space portion 71 extending in the tire circumferential direction and an axial space portion 72 extending in the tire axial direction, and the circumferential space portion 71 and the axial space portion 72 communicate with each other. Pneumatic tire.

[0055] As a result, the puncture repair agent can flow in both the circumferential direction and the axial direction, and the puncture repair agent can penetrate into the damaged portion evenly in a shorter time.

[0056] (3) In the pneumatic tire according to (1) or (2), the surface of the sound-absorbing material 60 facing the inner surface 501 of the tire is a flat surface along the inner surface 501 of the tire, and the minimum distance h in the tire radial direction between the surface of the sound-absorbing material 60 facing the inner surface 501 of the tire and the inner surface 501 of the tire is 1 mm or more and 10 mm or less. Pneumatic tire.

[0057] As a result, while maintaining the durability of the sound-absorbing material, the puncture repair agent can easily enter the space portions (71, 72).

[0058] (4) In the pneumatic tire according to (2), the width of the circumferential space portion 71 in the tire axial direction is 5 mm or more and 25 mm or less. Pneumatic tire.

[0059] As a result, while maintaining the durability of the sound-absorbing material, the puncture repair agent can easily enter the circumferential space portion 71.

[0060] (5) In the pneumatic tire according to (2), the width of the axial space portion 72 in the tire circumferential direction is 5 mm or more and 25 mm or less. Pneumatic tire.

[0061] This enables the puncture repair agent to easily penetrate into the axial space portion 72 while maintaining the durability of the sound-absorbing material.

[0062] (6) The pneumatic tire according to any one of (2) to (5), wherein a plurality of the circumferential space portions 71 are provided, and the plurality of circumferential space portions 71 are arranged at equal intervals.

[0063] This allows the puncture repair agent to be evenly distributed on the inner surface 501 of the tire.

[0064] (7) The pneumatic tire according to any one of (2) to (6), wherein a plurality of the axial space portions 72 are provided, and the plurality of axial space portions 72 are arranged at equal angular intervals along the inner surface 501 of the tire.

[0065] This allows the puncture repair agent to be evenly distributed on the inner surface 501 of the tire.

[0066] (8) The pneumatic tire according to any one of (1) to (7), wherein the sound-absorbing material 60 is substantially rectangular parallelepiped-shaped in a free state, and one or a plurality of the sound-absorbing materials 60 are arranged with their end portions 61 butted against each other in the circumferential direction at the butting portion 62 along the inner surface 501 of the tire, and the bonding material 70 is provided between the butting portion 62 and the inner surface 501 of the tire.

[0067] This can suppress the peeling of the sound-absorbing material 60 from the end portion 61 of the sound-absorbing material 60 and improve the durability.

[0068] (9) The pneumatic tire according to (8), wherein the space portions (71, 72) are not provided between the butting portion (62) and the inner surface 501 of the tire.

[0069] This can suppress the peeling of the sound-absorbing material 60 from the end portion 61 of the sound-absorbing material 60, and can further improve the durability.

[0070] (Modified form) The present disclosure is not limited to the embodiments described above, and various modifications and changes are possible, and they are also within the scope of the present disclosure.

[0071] (Modified form 1) For example, in the embodiment, an example in which an adhesive is used as the bonding material 70 has been described. However, the present disclosure is not limited to this. For example, a double-sided adhesive tape may be used as the bonding material 70. When a double-sided adhesive tape is used as the bonding material 70, by setting the thickness of the base material of the double-sided adhesive tape to an appropriate thickness, the distance between the inner surface 501 of the tire in the space portion and the sound-absorbing material 60 can be easily and stably formed at a predetermined distance.

[0072] (Modified form 2) Further, as the bonding material 70, an adhesive and a double-sided adhesive tape may be used in combination. In this case, the double-sided adhesive tape functions as a spacer for maintaining the distance between the inner surface 501 of the tire in the space portion and the sound-absorbing material 60, and the adhesive can exhibit a higher bonding force.

[0073] It should be noted that the embodiments and the modified forms can be used in appropriate combinations, but detailed descriptions thereof are omitted. Further, the present disclosure is not limited by the embodiments described above.

Explanation of reference numerals

[0074] 1 Tire (pneumatic tire) 10 Bead 11 Bead core 12 Bead filler 13 Chafer 14 Rim strip rubber 20 Sidewall 21 Sidewall rubber 30 Tread 31 Belt 32 Cap ply 33 Tread rubber 34 Tread pattern 37 Tread surface 40 Carcass ply 50 Inner liner 60 Sound-absorbing material 61 End part 62 Joint part 70 Bonding material 71 Circumferential space part 72 Axial space part 341 Main groove 501 Tire inner surface LS Tire inner cavity space

Claims

1. A sound-absorbing material provided on the inner surface of a tire, An adhesive for joining the inner surface of the tire and the sound-absorbing material, comprising A space portion where the adhesive is not provided is provided at a position where the inner surface of the tire and the sound-absorbing material face each other, The space portion communicates with the inner cavity space of the tire radially inside the sound-absorbing material. A pneumatic tire.

2. In the pneumatic tire according to Claim 1, The space portion A circumferential space portion extending in the circumferential direction of the tire, An axial space portion extending in the axial direction of the tire, having The circumferential space portion and the axial space portion communicate with each other. A pneumatic tire.

3. In the pneumatic tire according to Claim 1 or Claim 2, The surface of the sound-absorbing material facing the inner surface of the tire is a flat surface along the inner surface of the tire, The minimum radial distance between the surface of the sound-absorbing material facing the inner surface of the tire and the inner surface of the tire is 1 mm or more and 10 mm or less. A pneumatic tire.

4. In the pneumatic tire according to Claim 2, The width of the circumferential space portion in the axial direction of the tire is 5 mm or more and 25 mm or less. A pneumatic tire.

5. In the pneumatic tire according to Claim 2, The width of the axial space portion in the circumferential direction of the tire is 5 mm or more and 25 mm or less. A pneumatic tire.

6. In the pneumatic tire according to Claim 2, A plurality of the circumferential space portions are provided, and the plurality of circumferential space portions are arranged at equal intervals. A pneumatic tire.

7. In the pneumatic tire according to claim 2, a plurality of the axial space portions are provided, and the plurality of the axial space portions are arranged at equal angular intervals along the inner surface of the tire. A pneumatic tire.

8. In the pneumatic tire according to claim 1 or claim 2, the sound absorbing material is substantially rectangular parallelepiped in a free state, and one or a plurality of the sound absorbing materials are arranged such that the ends of the sound absorbing materials are butted against each other in the circumferential direction at the butting portion along the inner surface of the tire, and the bonding material is provided between the butting portion and the inner surface of the tire. A pneumatic tire.

9. In the pneumatic tire according to claim 8, no space portion is provided between the butting portion and the inner surface of the tire. A pneumatic tire.

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