Pneumatic tire

Abstract

To provide a pneumatic tire which comprises an acoustic absorbent, nonetheless enables a puncture repair agent to be properly permeated into the necessary portion of the tire, which therefore has high durability.SOLUTION: A tire 1 is provided with an acoustic absorbent 60 provided on a tire inner surface 501 and joining material 70 joining the tire inner surface 501 to the acoustic absorbent 60. The acoustic absorbent 60 is formed in a bent or curved shape so that the absorbent protrudes towards inside in a tire radial direction. A space portion 63 is formed in radial outside of the acoustic absorbent 60. The acoustic absorbent 60 is joined to the tire inner surface 501 at least at two separate joining portions 61 and 62, using the joining material 70.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 thereby reduce in-vehicle noise (see, for example, Patent Document 1).

[0003] In the pneumatic tire of Patent Document 1, a sound-absorbing material (porous material) formed flat in the cross section in the tire axial direction is joined to the inner surfaces of a pair of sidewalls facing each other in the tire axial direction. As a result, it is easier for the puncture repair agent to reach the inner surface of the tread.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, the sidewall of the tire has many opportunities to bend and deform. Therefore, in the form in which the sound-absorbing material is joined to the inner surface of the sidewall as in Patent Document 1, there is a high possibility that the joint portion of the sound-absorbing material is peeled off by the force due to the bending of the sidewall, and the durability is poor.

[0006] An object of the present disclosure is to provide a pneumatic tire that has a sound-absorbing material, allows the puncture repair agent to appropriately penetrate easily, and has high durability of the sound-absorbing material.

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. The sound-absorbing material has a shape bent or curved so as to be convex toward the inner side in the tire radial direction. A space is formed on the outer side in the tire radial direction of the sound-absorbing material. The sound-absorbing material is joined to the inner surface of the tire using the adhesive at at least two separated joining portions.

Advantages of the Invention

[0008] According to the present disclosure, even if a sound-absorbing material is provided, a puncture repair agent can easily penetrate appropriately, and a pneumatic tire with high durability of the sound-absorbing material can be provided.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

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

[0011] (First Embodiment) FIG. 1 is a cross-sectional view of a pneumatic tire 1 according to the first embodiment of the present disclosure in the tire axial direction. FIG. 2 is a schematic view of a cross-section obtained by cutting the tire 1 of the first embodiment along the tire equatorial plane S1. In FIG. 2, only main parts such as the bead 10, the tread 30, the inner liner 50, the sound-absorbing material 60, and the bonding material 70 are shown, and the belt 31 and the like are omitted. Note that each of the figures shown below, including FIG. 1, is a schematically shown figure, and the size and shape of each part are exaggerated or omitted as appropriate for easy understanding. Further, in the following description, specific numerical values, shapes, materials, etc. are shown for the description, 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 in the cross-section in the tire axial direction (tire width direction). In the figure, the symbol S1 is the tire equatorial plane. The tire equatorial plane S1 is a plane orthogonal to the tire rotation axis (tire meridian) and is located at the center in the tire axial direction.

[0013] Note that the cross-sectional view of FIG. 1 is a cross-sectional view (tire meridian cross-sectional view) of the tire 1 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 a 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 shown as the tire axial direction X. Also, in this tire axial direction, for convenience of explanation, the left side of the tire equatorial plane S1 in FIG. 1 is called the first end side, and the right side of the tire equatorial plane S1 is called the second end side. And the inner side in the tire axial direction is a 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 a 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] The tire radial direction is the direction perpendicular to the tire rotation axis and is the vertical direction of the paper 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, which is the lower side of the paper in FIG. 1. The inner side in the tire radial direction is the direction approaching the tire rotation axis, which is the upper side of the paper in FIG. 1.

[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 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 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 times a metal bead wire coated with rubber, 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. 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, a rubber having a higher hardness than the surrounding rubber members.

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

[0021] The rim strip rubber 14 is disposed on the tire axial direction outer side 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 tire axial direction outer side of the carcass ply 40. The sidewall rubber 21 constitutes the outer wall surface of the tire 1. The sidewall rubber 21 is the part that bends the most when the tire 1 exerts a cushioning effect, 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 tire radial direction outer side of the carcass ply 40. The cap ply 32 is disposed on the tire radial direction outer side of the belt 31.

[0025] The belt 31 is a member that reinforces 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. In the present embodiment, the inner belt 311 is wider than the outer belt 312. Therefore, the maximum width belt having the widest width in the tire axial direction is the belt 311. 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 three-layer or more structure.

[0026] The cap ply 32 is a member that reinforces 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 tire diameter direction outer side 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, 342, 343, 344 arranged in the tire axial direction. Each of the plurality of main grooves 341 to 344 extends along the tire circumferential direction. In the present embodiment, four main grooves are illustrated as an example, but the number of main grooves may be three or less or five or more. In the present embodiment, the main groove closest to one sidewall 20 in the tire axial direction is also referred to as the first end side main groove 341. Similarly, the main groove 344 closest to the other sidewall 20 in the tire axial direction is also referred to as the second end side main groove 344.

[0028] The tread surface 37 has a ground contact width region which is a region that actually contacts the road surface in the tire axial direction. The ground contact width region is between the ground contact ends 37g at both ends of the tread surface 37 in the tire axial direction.

[0029] Here, the ground contact width region refers to the region in the tire axial direction that contacts the road surface under the condition that an inflated tire mounted on a regular rim and filled with a regular internal pressure is in contact with the road surface and a regular load is applied thereto. The regular load is the load determined for each tire in a standard system including the standard on which the tire is based. For JATMA, it is the "maximum load capacity", for TRA, it is the maximum value described in the table "TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES", and for ETRTO, it is the "LOAD CAPACITY". When the tire is for a passenger car, it is a load corresponding to 88% of the above load. When the tire is for a racing kart, the regular load is 392 N.

[0030] 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 a manner that 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 or polyamide cords. The plurality of carcass cords are coated with rubber to form the carcass ply 40.

[0031] The carcass ply 40 extends from one bead core 11 to the other bead core 11 and has a ply body portion 401 that extends between the tread 30 and the bead 10, a pair of bent portions 402 that are folded back at the bead core 11 from the ply 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 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 body portion 401.

[0032] 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.

[0033] 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 axially outside the tire 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.

[0034] The inner liner 50 covers the inner surface of the ply body portion 401 of the carcass ply 40 and the inner surfaces of the chafer 13 of the pair of beads 10. The inner liner 50 is made of an air-permeability-resistant rubber and prevents the air in the tire 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.

[0035] As shown in FIG. 1, the tire 1 according to the present embodiment further includes a sound-absorbing material 60 and an adhesive 70.

[0036] The adhesive 70 is provided between the tire inner surface 501 and the joints 61, 62 of the sound-absorbing material 60 and joins the tire inner surface 501 and the sound-absorbing material 60. As the adhesive 70, an adhesive may be used, or a double-sided adhesive tape may be used, but an adhesive for rubber or a tire is preferably used. The adhesive 70 that adheres 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".

[0037] The sound-absorbing material 60 is joined to the tire inner surface 501 by the adhesive 70. The sound-absorbing material 60 of the embodiment is a sponge provided with a large number of pores formed of a foamed 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 70. The sound-absorbing material 60 of the embodiment is arranged symmetrically with the tire equatorial plane S1 as the center plane of symmetry.

[0038] One member pre-formed in an annular shape is joined to the tire inner surface 501 for the sound-absorbing material 60 (see FIG. 2). Note that the sound-absorbing material 60 may be configured in an annular shape by two or more members divided in the tire circumferential direction, or may be intermittently arranged in the tire circumferential direction at a predetermined interval instead of in an annular shape. When the sound-absorbing material 60 is intermittently arranged in the tire circumferential direction at a predetermined interval, the both ends in the extending direction of the sound-absorbing material may be in an open form.

[0039] In the following description, an example will be given in which the sound-absorbing material 60 is provided by joining one annularly formed member to the inner surface 501 of the tire. The sound-absorbing material 60 absorbs various sounds generated in the inner cavity of the tire 1 during running to reduce noise.

[0040] From the viewpoint of weight balance in the tire 1, the sound-absorbing material 60 has a density of 60 kg / m 3 The following is preferable, and a density of 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).

[0041] In the cross-section in the tire axial direction shown in FIG. 1, the sound-absorbing material 60 has a substantially arch-like shape that curves convexly toward the inner side in the tire radial direction, and a space portion 63 is formed on the outer side of the sound-absorbing material 60 in the tire radial direction. That is, the sound-absorbing material 60 has a substantially semi-cylindrical cross-sectional shape and extends along the circumferential direction of the inner surface of the tire. Note that the substantially semi-cylindrical shape is not limited to a shape that exactly divides the cylindrical shape in half, but includes a shape that can be regarded as dividing the cylindrical shape along the extending direction of the cylindrical shape. Since the sound-absorbing material 60 has such a shape, that is, a substantially arch-like shape that curves convexly toward the inner side in the tire radial direction in the cross-sectional view in the tire axial direction, it is possible to effectively suppress the sound-absorbing material 60 from being deformed by the centrifugal force received by the sound-absorbing material 60 when the tire 1 is in use (rotating).

[0042] The dimensions of the sound-absorbing material 60 are selected according to the dimensions of the tire 1 and the like. For example, the height in the radial direction, that is, the height h (see FIG. 1) from the inner surface 501 of the tire to the innermost surface of the sound-absorbing material 60 in the tire radial direction at the position of the tire equatorial plane S1 is desirably 20 mm or more and 50 mm or less. Further, the sound-absorbing material 60 is desirably configured with a substantially uniform thickness t (see FIG. 1), and the thickness t is desirably 10 mm or more and 30 mm or less.

[0043] The sound-absorbing material 60 is joined to the inner surface 501 of the tire using a joining material 70 at two spaced-apart joints 61 and 62 in the cross-sectional view in the tire axial direction shown in FIG. 1. The sound-absorbing material 60 is curved so as to be convex toward the inner side in the tire radial direction, and a space 63 is formed on the outer side in the tire radial direction. Also, the sound-absorbing material 60 is joined at two spaced-apart joints 61 and 62. With this configuration, most of the region of the inner surface 501 of the tire corresponding to the inner surface side of the tread 30 is a region that does not come into contact with either the sound-absorbing material 60 or the joining material 70. Therefore, when a puncture repair agent is used, the puncture repair agent can reach the inner surface 501 of the tire without being absorbed by the sound-absorbing material 60, and the probability of successful puncture repair can be increased. The puncture repair agent is injected into the tire inner cavity space LS, but since the space 63 is formed between the sound-absorbing material 60 and the inner surface 501 of the tire, it can reach the inner surface 501 of the tire through the sound-absorbing material 60.

[0044] Here, the positions of the two spaced-apart joints 61 and 62 are important from the viewpoint of preventing the sound-absorbing material 60 from peeling off from the inner surface 501 of the tire, that is, from the viewpoint of durability. From the viewpoint of durability, it is desirable that the positions of the joints 61 and 62 be positions where the tire 1 is less likely to deform, and the closer to the tire equatorial plane S1, the more desirable. On the other hand, in order to enhance the original function of the sound-absorbing material 60, that is, the effect of reducing the cavity resonance occurring in the tire inner cavity, it is desirable that the positions of the joints 61 and 62 be arranged more on the outer side in the tire axial direction of the tire 1 because the range of the sound-absorbing material 60 becomes larger. Therefore, considering these balances, it can be said that the following range is desirable.

[0045] (Range 1) It is desirable that the joints 61 and 62 be provided within a range overlapping with the maximum-width belt 311 having the widest width in the tire axial direction among the belts 31 when viewed from the outside in the tire radial direction. That is, it is desirable that the joints 61 and 62 be arranged at positions overlapping between the end portion 311a on the first end side and the end portion 311b on the second end side of the maximum-width belt 311. In the present embodiment, the end on the first end side of the joint 61 is arranged on the inner side in the tire axial direction than the end portion 311a on the first end side of the maximum-width belt 311. Further, the end on the second end side of the joint 62 is arranged on the inner side in the tire axial direction than the end portion 311b on the second end side of the maximum-width belt 311.

[0046] This range is a range reinforced by at least one belt (the maximum-width belt 311) and is a range in which the deformation of the tread 30 is suppressed. Therefore, the amount of deformation received by the joints 61 and 62 of the sound-absorbing material 60 can also be suppressed, and the durability of the sound-absorbing material 60 can be enhanced.

[0047] (Range 2) It is desirable that the joints 61 and 62 be provided within a range overlapping with the range where the belts 31 are most overlapped when viewed from the outside in the tire radial direction. The belt 31 of the present embodiment has a two-layer structure including the inner belt 311 and the outer belt 312, and the outer belt 312 is narrower than the inner belt 311. Therefore, in the tire 1 of the present embodiment, the range where the belts 31 are most overlapped is a range overlapping with the outer belt 312 when viewed from the outside in the tire radial direction. That is, it is desirable that the joints 61 and 62 be arranged at positions overlapping between the end portion 312a on the first end side and the end portion 312b on the second end side of the outer belt 312. In the present embodiment, the end on the first end side of the joint 61 is arranged on the inner side in the tire axial direction than the end portion 312a on the first end side of the outer belt 312. Further, the end on the second end side of the joint 62 is arranged on the inner side in the tire axial direction than the end portion 312b on the second end side of the outer belt 312. Note that, in the case of a three-layer structure belt, it is a range overlapping with three belts, and in the case of a four-layer structure belt, it is a range overlapping with four belts.

[0048] This range is the range reinforced by the most belts and is a range where the deformation of the tread 30 is further suppressed. Therefore, the amount of deformation received by the joints 61 and 62 of the sound-absorbing material 60 can be further suppressed, and the durability of the sound-absorbing material 60 can be enhanced.

[0049] (Range 3) In addition, as shown in the third embodiment (FIG. 4) described later, the joints 61 and 62 may be provided within a range overlapping the ground contact width region when viewed from the outer side in the tire diameter direction. That is, the joints 61 and 62 may be arranged at a position overlapping between the ground contact ends 37g near the ends in the tire axial direction of the tread surface 37. In such an embodiment, the end on the first end side of the joint 61 is arranged on the inner side in the tire axial direction than the ground contact end 37g on the first end side. Also, the end on the second end side of the joint 62 is arranged on the inner side in the tire axial direction than the ground contact end 37g on the second end side. In such an embodiment, in the tire axial direction, the ground contact width region is narrower than the width of the belt 31. Therefore, since it is a range where the deformation of the tread 30 is further suppressed, the amount of deformation received by the joints 61 and 62 of the sound-absorbing material 60 can be further suppressed, and the durability of the sound-absorbing material 60 can be enhanced.

[0050] (Range 4) Note that, as shown in the third embodiment (FIG. 4) described later, the joint portions 61 and 62 may be provided within a range overlapping with the range sandwiched between the first end-side main groove 341 and the second end-side main groove 344 when viewed from the outside in the tire radial direction. In such an embodiment, the end on the first end side of the joint portion 61 is arranged on the inner side in the tire axial direction than the end on the first end side of the first end-side main groove 341. Further, the end on the second end side of the joint portion 62 is arranged on the inner side in the tire axial direction than the end on the second end side of the second end-side main groove 344. In such an embodiment, since the main groove is arranged on the inner side in the tire axial direction than the ground contact width region, the deformation of the tread 30 within the range where the main groove is provided is further suppressed compared to the above range 1 to range 3. Therefore, by arranging the joint portions 61 and 62 in this range 4, the durability of the sound-absorbing material 60 can be enhanced compared to the case of other ranges.

[0051] As described above, from the viewpoint of durability, the width in the tire axial direction becomes narrower and the durability becomes higher in the order of (range 1) to (range 4), so (range 4) is the most desirable. On the other hand, from the viewpoint of the effect of reducing cavity resonance, (range 1) is the most desirable. Therefore, the selection of these (range 1) to (range 4) can be appropriately selected according to the characteristics required for the tire 1.

[0052] Any position from the above-mentioned (Range 1) to (Range 4) is within the range that overlaps with the tread 30 when viewed from the outer side in the tire radial direction, and at least the sidewall 20 is not included. Since the vicinity of the tread 30 is less likely to bend and deform than the sidewall 20, within the range from the above-mentioned (Range 1) to (Range 4), it is possible to improve the durability of the sound-absorbing material 60 compared to the prior art. On the other hand, the tread 30 is a part where the frequency of puncture due to the penetration of nails or the like is high. If the sound-absorbing material 60 is directly attached to the inner surface side of the tread 30, the puncture repair agent will be absorbed by the sound-absorbing material 60, so that the puncture repair agent cannot sufficiently penetrate into the damaged part, and there has been a conventional risk that the probability of successful puncture repair will be low. However, the sound-absorbing material 60 of the present embodiment has a curved shape that protrudes toward the inner side in the tire radial direction, and a space portion 63 is formed on the outer side of the sound-absorbing material 60 in the tire radial direction. Therefore, the puncture repair agent can easily reach the tire inner surface 501 on the inner surface side of the tread 30, and the probability of successful puncture repair can be increased.

[0053] According to the tire 1 according to the above-described embodiment, the following effects can be obtained.

[0054] (1) The tire 1 according to the present embodiment includes a sound-absorbing material 60 provided on the tire inner surface 501 and an adhesive 70 that joins the tire inner surface 501 and the sound-absorbing material 60. The sound-absorbing material 60 has a bent or curved shape that protrudes toward the inner side in the tire radial direction, a space portion 63 is formed on the outer side of the sound-absorbing material 60 in the tire radial direction, and the sound-absorbing material 60 is joined to the tire inner surface 501 using the adhesive 70 at at least two spaced-apart joining portions 61, 62.

[0055] Thereby, when a puncture repair agent is used, the puncture repair agent can reach the tire inner surface 501 of the portion covered by the sound-absorbing material 60, and the probability of successful puncture repair can be increased.

[0056] In the pneumatic tire described in (2)(1), a pair of beads 10, 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 extending from the tread 30 to the bead 10, and at least one layer of belt 31 disposed radially outside the carcass ply 40 in the tread 30, wherein the joints 61, 62 are provided within a range overlapping with the widest-width belt 311 having the widest width in the tire axial direction among the belts 31 when viewed from the outside in the tire diameter direction. A pneumatic tire.

[0057] As a result, since the joints 61, 62 are disposed within the range reinforced by at least one layer of belt (widest-width belt 311), the joints 61, 62 are difficult to peel off, and the durability of the sound-absorbing material 60 can be enhanced.

[0058] (3) In the pneumatic tire described in (2), the joints 61, 62 are provided within a range overlapping with the range where the belts 31 are most overlapped when viewed from the outside in the tire diameter direction. A pneumatic tire.

[0059] As a result, since the joints 61, 62 are disposed within the range where the reinforcing effect by the belt 31 is the highest, the joints 61, 62 are difficult to peel off, and the durability of the sound-absorbing material 60 can be further enhanced.

[0060] (4) In the pneumatic tire described in (2), the tread 30 is provided with a plurality of main grooves 341 to 344 extending along the tire circumferential direction, the main grooves 341 to 344 have a first end-side main groove 341 closest to one of the sidewalls 20 in the tire axial direction and a second end-side main groove 344 closest to the other sidewall 20 in the tire axial direction, and the joints 61, 62 are provided within a range overlapping with the range sandwiched between the first end-side main groove 341 and the second end-side main groove 344 when viewed from the outside in the tire diameter direction. A pneumatic tire.

[0061] As a result, since the joints 61 and 62 are arranged within a range with less deformation where the main groove is provided, the joints 61 and 62 are less likely to peel off, and the durability of the sound absorbing material 60 can be further enhanced.

[0062] (5) The pneumatic tire according to any one of (1) to (4), wherein the sound absorbing material 60 has a substantially semi-cylindrical cross-sectional shape and extends along the inner surface 501 of the tire.

[0063] As a result, it is possible to effectively suppress the deformation of the sound absorbing material 60 due to the centrifugal force received by the sound absorbing material 60 during the use (rotation) of the tire 1.

[0064] (6) The pneumatic tire according to any one of (1) to (5), wherein both ends of the sound absorbing material 60 in the extending direction may be open.

[0065] As a result, it is possible to facilitate the entry of the puncture repair agent into the space portion 63 from the opening.

[0066] (7) The pneumatic tire according to any one of (1) to (6), wherein the sound absorbing material 60 extends along the tire circumferential direction.

[0067] As a result, it becomes possible to continuously arrange the sound absorbing material 60 along the inner surface 501 of the tire on the back side of the tread 30, and the sound absorption effect can be enhanced.

[0068] (Second Embodiment) FIG. 3 is a cross-sectional view in the tire axial direction of a tire 1B which is a pneumatic tire according to the second embodiment of the present disclosure. The tire 1B of the second embodiment has the same form as the first embodiment except that the form of the sound absorbing material 60B is different from that of the sound absorbing material 60 of the first embodiment. Therefore, the same reference numerals are given to the parts that perform the same functions as those in the first embodiment described above, and the overlapping descriptions are appropriately omitted.

[0069] In the cross-section in the tire axial direction shown in FIG. 3, the sound-absorbing material 60B of the second embodiment is bent so as to be convex toward the inner side in the tire radial direction, and has a substantially U-shaped form with substantially right-angled corners. A space portion 63 is formed on the outer side in the tire radial direction of the sound-absorbing material 60B.

[0070] According to the tire 1B of the second embodiment, even in the form of the sound-absorbing material 60B, the same effects as those of the tire 1 of the first embodiment can be achieved.

[0071] (Third Embodiment) FIG. 4 is a cross-sectional view in the tire axial direction of a pneumatic tire 1C according to the third embodiment of the present disclosure. The tire 1C of the third embodiment has the same form as that of the first embodiment except that the form of the sound-absorbing material 60C is different from that of the sound-absorbing material 60 of the first embodiment. Therefore, the same reference numerals are given to the parts that perform the same functions as those in the first embodiment described above, and the overlapping descriptions are appropriately omitted.

[0072] In the cross-section in the tire axial direction shown in FIG. 4, the sound-absorbing material 60C of the third embodiment is bent so as to be convex toward the inner side in the tire radial direction, and is formed in a partial shape of a triangular shape with a pointed center. A space portion 63 is formed on the outer side in the tire radial direction of the sound-absorbing material 60C. In the present embodiment, the joint portions 61 and 62 are provided within a range overlapping the ground contact width region when viewed from the outer side in the tire radial direction (range 3). Further, in the present embodiment, the joint portions 61 and 62 are provided within a range overlapping the range sandwiched between the first end-side main groove 341 and the second end-side main groove 344 when viewed from the outer side in the tire radial direction (range 4). However, the present invention is not limited to this, and for example, the joint portions may be provided in the above-described (range 1) and (range 2).

[0073] According to the tire 1C of the third embodiment, even in the form of the sound-absorbing material 60C, the same effects as those of the tire 1 of the first embodiment can be achieved.

[0074] (Fourth Embodiment) FIG. 5 is a schematic cross-sectional view of a pneumatic tire 1D according to the fourth embodiment of the present disclosure, taken along the tire equatorial plane S1. FIG. 5 shows only the main parts, similar to FIG. 2, and omits the belt 31 and the like. The tire 1D of the fourth embodiment has the same form as the first embodiment, except that the form of the sound-absorbing material 60D is different from that of the sound-absorbing material 60 of the first embodiment. Therefore, parts that perform the same functions as those in the first embodiment described above are denoted by the same reference numerals, and duplicate descriptions are appropriately omitted.

[0075] The sound-absorbing material 60D of the fourth embodiment has a substantially arch-like shape that curves convexly toward the inner side in the tire radial direction in the cross-section of the tire equatorial plane S1 shown in FIG. 5, and a space portion 63 is formed outside the sound-absorbing material 60D in the tire radial direction. The sound-absorbing material 60D extends along the tire axial direction. In the present embodiment, as shown in FIG. 5, five sound-absorbing materials 60D are arranged at equal angular intervals along the tire circumferential direction. Note that the number of sound-absorbing materials 60D arranged along the tire circumferential direction may be four or less, or six or more.

[0076] Both ends of the sound-absorbing material 60D are open, and this opening makes it easier for the puncture repair agent to enter the space portion 63. And since a plurality (five in the present embodiment) of sound-absorbing materials 60D are arranged, it is easy to enter the space portion 63, and the possibility of successful puncture repair can be further increased.

[0077] According to the tire 1D according to the fourth embodiment described above, the following effects can be obtained.

[0078] (8) In the pneumatic tire according to any one of (1) to (6), the sound-absorbing material 60D extends along the tire axial direction, the pneumatic tire.

[0079] Thereby, the possibility of successful puncture repair can be further increased.

[0080] (Variant form) Without being limited to the embodiments described above, various modifications and changes are possible, and these are also within the scope of the present disclosure.

[0081] (Variant Form 1) In each embodiment, a communication hole may be provided in a part of the sound-absorbing materials 60 to 60D to communicate the tire inner cavity space LS and the space portion 63, so that the puncture repair agent can more easily reach the space portion 63. This communication hole may be provided at one location, but if provided at a plurality of locations, the effect of making it easier for the puncture repair agent to reach the space portion 63 can be further enhanced.

[0082] (Variant Form 2) Further, in the first to third embodiments, an example in which the sound-absorbing materials 60 to 60C are continuously provided in an annular shape in the circumferential direction has been described. However, the present invention is not limited to this. For example, the sound-absorbing material may be partially divided in the circumferential direction, that is, arranged discontinuously in the circumferential direction, so that the puncture repair agent can more easily reach the space portion 63.

[0083] (Variant Form 3) In each embodiment, a portion where the bonding material 70 is not provided partially may be formed, that is, the bonding material 70 may be provided in a discontinuous form, so that the puncture repair agent can more easily reach the space portion 63.

[0084] (Variant Form 4) In each embodiment, an example in which an adhesive is used as the bonding material 70 has been described. However, the present invention is not limited to this. For example, a double-sided adhesive tape may be used as the bonding material 70.

[0085] It should be noted that each embodiment and variant form can be used in appropriate combination, but detailed description is omitted. Further, the present disclosure is not limited by each of the embodiments described above.

Explanation of Reference Numerals

[0086] 1, 1B, 1C, 1D Tires 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 37g Ground Contact End 40 Carcass Ply 50 Inner Liner 60, 60B, 60C, 60D Sound Absorbing Material 61, 62 Joint 63 Space Part 70 Adhesive 311 Belt (Maximum Width Belt) 311a, 311b End 312 Belt 312a, 312b End 341 Main Groove (First End Side Main Groove) 342 Main Groove 343 Main Groove 344 Main Groove (Second End Side Main Groove) 501 Tire Inner Surface

Claims

1. A sound-absorbing material provided on the inner surface of the tire, An adhesive for joining the inner surface of the tire and the sound-absorbing material, comprising The sound-absorbing material has a shape bent or curved so as to be convex toward the inner side in the tire radial direction, A space is formed on the outer side in the tire radial direction of the sound-absorbing material, The sound-absorbing material is joined to the inner surface of the tire using the adhesive at at least two spaced-apart joints. A pneumatic tire.

2. In the pneumatic tire according to claim 1, A pair of beads, A pair of sidewalls extending radially outward from each of the pair of beads, A tread disposed between the pair of sidewalls, A carcass ply extending from the tread to the bead, At least one layer of belt disposed on the outer side in the tire radial direction of the carcass ply in the tread, comprising The joint is provided within a range overlapping with the maximum-width belt having the widest width in the tire axial direction among the belts when viewed from the outer side in the tire radial direction. A pneumatic tire.

3. In the pneumatic tire according to claim 2, The joint is provided within a range overlapping with the range where the belts are most overlapped when viewed from the outer side in the tire radial direction. A pneumatic tire.

4. In the pneumatic tire according to claim 2, A plurality of main grooves extending along the tire circumferential direction are provided in the tread, The main grooves include a first end-side main groove closest to one of the sidewalls in the tire axial direction and a second end-side main groove closest to the other sidewall in the tire axial direction. The pneumatic tire, wherein the joint portion is provided within a range overlapping with a range sandwiched between the first end-side main groove and the second end-side main groove when viewed from the outer side in the tire radial direction.

5. In the pneumatic tire according to claim 1 or claim 2, The pneumatic tire, wherein the sound-absorbing material has a substantially semi-cylindrical cross-sectional shape and extends along the inner surface of the tire.

6. In the pneumatic tire according to claim 5, The pneumatic tire, wherein both ends in the extending direction of the sound-absorbing material are open.

7. In the pneumatic tire according to claim 5, The pneumatic tire, wherein the sound-absorbing material extends along the tire circumferential direction.

8. In the pneumatic tire according to claim 5, The pneumatic tire, wherein the sound-absorbing material extends along the tire axial direction.

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