JP2019014281A - Pneumatic tire and assembly - Google Patents

Abstract

To provide a pneumatic tire and an assembly, which can prevent lowering of radiation performance in the vicinity of a belt end of an innermost belt layer in a radial direction while exhibiting performance for reducing cavity resonance energy.SOLUTION: A pneumatic tire includes a carcass, one or more belt layers and a tread rubber, and includes a noise damper which is adhered to a tread inner surface positioned on a reverse side of the tread rubber out of a tire inner surface and covers a predetermined area of the tire inner surface, where the one or more belt layers include an inner most belt layer in a radial direction positioned at the innermost side in the tire radial direction, the predetermined area of the tire inner surface is an area astride a belt end position of the tire inner surface that overlaps the belt end in the tire width direction of the innermost belt layer in the radial direction in the tire radial direction, in the tire width direction, and the sound damper covers the belt end position of the tire inner surface without being adhered to the belt end position of the tire inner surface.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pneumatic tire and an assembly.

  One of the tire noises is so-called road noise that produces a “go” sound in a frequency range of 50 to 400 Hz when traveling on a road surface. As its main cause, resonance vibration of air (cavity resonance) occurring in the tire lumen is known. Patent Document 1 discloses a technique for reducing road noise by disposing a noise control body in a tire lumen and controlling the resonance energy by absorbing cavity resonance energy.

Japanese Patent No. 4318639

  In the pneumatic tire described in Patent Document 1, the sound damping body is fixed to the tire cavity surface. For this reason, even when a large centrifugal force or lateral force acts on the sound absorber during high-speed rotation, the sound absorber itself does not frequently collide with the tire cavity surface. Thereby, in the pneumatic tire of patent documents 1, damage and destruction of a sound control object can be controlled, and as a result, suppression of cavity resonance can be maintained over a long period of time.

  By the way, when the sound absorber is fixed to the tire inner surface, the region where the noise absorber is fixed on the tire inner surface and the vicinity thereof are likely to store heat by the heat insulating action of the sound absorber. As a result, the cavity resonance energy can be reduced, but deterioration due to heat is promoted, and durability may be reduced.

  In particular, the vicinity of the belt end of the belt disposed outside the carcass in the tire radial direction tends to generate heat. When the vicinity of the belt end is deteriorated by heat, separation or the like may occur between the belt end and surrounding members. In addition, among the plurality of belt layers constituting the belt, the radially innermost belt layer located on the innermost side in the tire radial direction is far from the tread tread surface (tread outer surface), and therefore the belt end of the radially innermost belt layer. The heat in the vicinity is hardly dissipated outside the tire.

  Therefore, the present invention provides a pneumatic tire and an assembly capable of suppressing a decrease in heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting a cavity resonance energy reduction performance. For the purpose.

The pneumatic tire according to the first aspect of the present invention includes a toroidal carcass straddling between a pair of bead portions, and one or more belt layers disposed on the outer side in the tire radial direction with respect to the carcass, A tread rubber disposed on the outer side in the tire radial direction of the carcass so as to cover the one or more belt layers, the tread located on the back side of the tread rubber on the inner surface of the tire The sound absorber is fixed to an inner surface and covers a predetermined region of the tire inner surface, and the one or more belt layers include a radially innermost belt layer positioned on the innermost side in the tire radial direction. The predetermined region of the tire inner surface overlaps the belt end of the radial innermost belt layer in the tire width direction in the tire radial direction, and the belt end position of the tire inner surface is defined as the tire width direction. In an area extending over the noise damper is that without the fixed to the belt end position of the tire inner surface, and covers the belt end position of the tire inner surface.
By providing the above configuration, it is possible to suppress a decrease in the heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting the cavity resonance energy reduction performance.

As one embodiment of the present invention, the noise damper is not fixed to the tire inner surface in the outer region outside the belt end position in the tire width direction in the predetermined region. Covering.
By providing the above configuration, it is possible to further suppress the deterioration of the heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting the cavity resonance energy reduction performance.

As one embodiment of the present invention, the predetermined region includes a region straddling the belt end position on one side in the tire width direction in the tire width direction, and a belt end position on the other side in the tire width direction in the tire width direction. The outer region includes a first outer region on the outer side in the tire width direction from the belt end position on the one side and a second outer side in the tire width direction from the belt end position on the other side. An outer region, and the sound damping body covers the tire inner surface without being fixed to the tire inner surface in the first outer region, and is fixed to the tire inner surface in the second outer region. The inner surface of the tire is covered without being damaged.
By providing the above configuration, the heat radiation performance in the vicinity of the belt end of the radially innermost belt layer is reduced while the cavity resonance energy reduction performance is exhibited in the vicinity of the belt ends on both sides of the radially innermost belt layer. Can be suppressed.

As one embodiment of the present invention, in the sound damping body, in the tire width direction, the region covering the tire inner surface without being fixed to the tire inner surface is defined as a non-adhering region, and in the tire width direction, When the region that is fixed to the tire inner surface and covers the tire inner surface is a fixed region, the maximum thickness of the sound damper in the non-fixed region is smaller than the minimum thickness of the noise suppressor in the fixed region. Is also thin.
By providing the above configuration, it is possible to further suppress the deterioration of the heat dissipation performance of the tire due to the provision of the non-adhering region.

As one embodiment of the present invention, the sound damping body includes a facing surface facing the tire inner surface, and a free surface positioned on the opposite side of the facing surface, and the free surface is formed on the tire inner surface. A flat portion extending along the ridge, and a peak portion protruding inward in the tire radial direction from the flat portion.
By providing the above configuration, the heat dissipation performance of the tire can be improved.

As one embodiment of the present invention, the free surface in the fixing region is provided with the flat portion and the crest portion, and the thickness of the noise damper at the position of the flat portion in the fixing region. The thickness is smaller than the thickness of the sound damper at the position of the peak, and thicker than the maximum thickness of the sound damper in the non-fixed region.
By providing the above configuration, not only the surface area can be increased, but also the volume of the noise control body in the tire lumen can be secured, and the cavity resonance energy reduction performance can be enhanced.

As one embodiment of the present invention, a gap is formed between the sound damping body and the tire inner surface in the outer region.
By providing the said structure, the thermal radiation efficiency of a tire can be improved.

As one embodiment of the present invention, the sound damping body is fixed to a region including a position intersecting the tire equator surface on the inner surface of the tread.
By providing the above configuration, the sound damping body itself can be further prevented from being broken or unfixed.

An assembly according to a second aspect of the present invention includes the pneumatic tire and a rim to which the pneumatic tire is attached.
By providing the above configuration, it is possible to suppress a decrease in the heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting the cavity resonance energy reduction performance.

  According to the present invention, there is provided a pneumatic tire and an assembly capable of suppressing a decrease in heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting a cavity resonance energy reduction performance. can do.

It is sectional drawing which shows the cross section which follows the tire width direction of the assembly as one Embodiment of this invention provided with the pneumatic tire as one Embodiment of this invention. It is sectional drawing of the pneumatic tire single-piece | unit shown in FIG. It is an expanded sectional view which expands and shows a part of pneumatic tire shown in FIG. FIG. 2 is a development view showing an inner surface of the pneumatic tire shown in FIG. 1. It is sectional drawing which shows the modification of the pneumatic tire shown in FIG.

  Hereinafter, a pneumatic tire and an assembly according to the present invention will be described with reference to FIGS. In each figure, the same code | symbol is attached | subjected to the common member and site | part.

  Hereinafter, unless otherwise specified, the dimensions, length relationships, positional relationships, etc. of each element are measured in a reference state in which a pneumatic tire is mounted on a rim, a predetermined internal pressure is filled, and no load is applied. And

Here, “rim” is an industrial standard effective in the area where pneumatic tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (The European Tire). and Rim Technical Organization's STANDARDDS MANUAL, in the United States, TRA (The Tile and Rim Association, Inc.) YEAR BOOK, etc. “Measuring Rim” (design rim in TRA's YEAR BOOK) (ie, “rim” above refers to the industry in the future in addition to the current size) Examples of “sizes that will be described in the future” include the sizes described as “FUTURE DEVELOPMENTS” in the ETRTO 2013 edition). In the case of a size not described in the above, it means a rim having a width corresponding to the bead width of the pneumatic tire.
The “predetermined internal pressure” refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size / ply rating, as described in the above JATMA YEAR BOOK, etc. In the case of a size having no air pressure, it means the air pressure (maximum air pressure) corresponding to the maximum load capacity defined for each vehicle on which the tire is mounted.

  FIG. 1 is a view showing an assembly 100 including a pneumatic tire 1 (hereinafter simply referred to as “tire 1”) and a rim 2. Specifically, FIG. 1 is a cross-sectional view (hereinafter referred to as a “cross-sectional view in the tire width direction”) of the assembly 100 showing a cross section including the tire rotation axis and parallel to the tire width direction A. FIG. 2 is a cross-sectional view showing a single tire 1 shown in FIG. FIG. 3 is an enlarged cross-sectional view showing an enlarged tread edge that is a part of the tire 1 shown in FIG. 1. 1 to 3 show the tire 1 and the assembly 100 in the reference state described above.

  In the assembly 100, the tire 1 is attached to the rim 2. The assembly 100 has an annular shape by a tire lumen surface constituted by an inner surface of the tire 1 (hereinafter referred to as “tire inner surface”) and an outer surface of the rim 2 (hereinafter referred to as “rim outer surface”). The tire lumen 101 is partitioned.

<Rim 2>
The rim 2 includes a rim body 2a to which a bead portion 1c described later of the tire 1 is mounted, and a disk 2b that holds the rim body 2a and is attached to an axle. The rim 2 of the present embodiment is a metal two-piece wheel rim, but is not limited to this, and may be a one-piece rim. Further, the rim body 2a protrudes outward in the tire radial direction B from both ends of the tire width direction A of the rim seat portion 2a1 in which a bead member 4 described later of the tire 1 is attached to the outer side in the tire radial direction B. A rim flange portion 2a2.

<Tire 1>
The tire 1 includes a tread portion 1a, a pair of sidewall portions 1b extending inward in the tire radial direction B from both ends in the tire width direction A of the tread portion 1a, and the inner side in the tire radial direction B of each sidewall portion 1b. And a pair of bead portions 1c provided at the end portions. The tire 1 of this embodiment is a tubeless type radial tire for a passenger car. Here, the “tread portion 1a” is parallel to the tire radial direction B passing through the belt ends (see “belt end Q” in FIG. 3) located on the outermost sides of both sides of the belt 6 in the tire width direction A described later. It means a portion sandwiched between two planes P1 and P2. Further, the “bead portion 1c” means a portion where a bead member 4 described later is located in the tire radial direction B. The “sidewall portion 1b” means a portion between the tread portion 1a and the bead portion 1c.

  The inner surface of the tire that defines the tire lumen 101 is an inner surface 31 of the tread portion 1a (hereinafter referred to as “tread inner surface 31”) and an inner surface 32 of the sidewall portion 1b, which are located on the back side of the tread rubber 7 described later. (Hereinafter referred to as “side wall inner surface 32”) and an inner surface 33 of the bead portion 1c (hereinafter referred to as “bead inner surface 33”).

  The tire 1 includes a sound control body 3, a bead member 4, a carcass 5, a belt 6, a tread rubber 7, a side rubber 8, and an inner liner 9.

[Suppression body 3]
As shown in FIGS. 2 and 3, the sound damping body 3 is fixed to the tread inner surface 31 of the tire inner surface and covers a predetermined region N of the tire inner surface. Details of the predetermined area N will be described later. The predetermined area N means an area facing the sound damper 3 in the tire radial direction B.

  The sound control body 3 is made of a sponge material. The sponge material is a sponge-like porous structure, and includes, for example, a so-called sponge having open cells in which rubber or synthetic resin is foamed. The sponge material includes a web-like material in which animal fibers, plant fibers, or synthetic fibers are entangled and connected together in addition to the above-described sponge. The above-mentioned “porous structure” is not limited to a structure having open cells but also includes a structure having closed cells.

  The sponge material as described above converts vibration energy of air in which voids formed on the surface or inside vibrate into heat energy. Thereby, cavity resonance in the tire lumen is suppressed, and as a result, road noise can be reduced. In addition, the sponge material is easily deformed such as contraction and bending. Therefore, even if the sound control body 3 formed of a sponge material is fixed to the inner surface 31 of the tread, it does not substantially affect the deformation of the tire 1 during traveling. That is, even if the sound control body 3 is fixed to the inner surface 31 of the tread, it is difficult to adversely affect the steering stability.

  Examples of the material of the sponge material include ether type polyurethane sponge, ester type polyurethane sponge, synthetic resin sponge such as polyethylene sponge, chloroprene rubber sponge (CR sponge), ethylene propylene rubber sponge (EPDM sponge), nitrile rubber sponge (NBR sponge). ) And other rubber sponges. In view of sound damping properties, lightness, foaming controllability, durability, and the like, it is preferable to use a polyurethane-based or polyethylene-based sponge including an ether-based polyurethane sponge.

  The material constituting the sound damper 3 may be any material that can be controlled so as to reduce the cavity resonance energy by relaxation, absorption, conversion to another energy (for example, thermal energy), or the like. The sponge material is not limited to the above.

  The specific gravity of the sponge material is preferably 0.005 to 0.06, and preferably 0.01 to 0.04 in consideration of the balance between the increase in tire weight and the effect of suppressing cavity resonance. Is more preferable, and 0.01 to 0.03 is particularly preferable.

  Furthermore, the volume of the sound damper 3 is preferably 0.4% to 20% of the total volume of the tire lumen 101. By securing the volume of the sound control body 3 to 0.4% or more with respect to the total volume of the tire lumen, it is easy to realize a desired amount (for example, 2 dB or more) of cavity resonance energy reduction effect. The sound damping body 3 is more preferably 1% or more of the total volume of the tire lumen 101, further preferably 2% or more, and particularly preferably 4% or more. On the other hand, even if the volume of the noise control body 3 exceeds 20% of the total volume of the tire lumen 101, improvement in the cavity resonance energy reduction effect cannot be expected. Rather, the weight balance of the assembly 100 may be deteriorated. From such a viewpoint, the volume of the sound damper 3 is more preferably 16% or less, and particularly preferably 10% or less of the total volume of the tire lumen 101. Note that the volume ratio described above is not related to the number of damping bodies 3. That is, in the case where there are a plurality of sound damping bodies 3, the same effect can be obtained if the sum of the volumes of the plurality of sound damping bodies 3 satisfies the above-described volume ratio relationship.

[Bead member 4]
The bead member 4 is embedded in the bead portion 1c. The bead member 4 includes a bead core 4a and a rubber bead filler 4b positioned on the outer side in the tire radial direction B with respect to the bead core 4a. The bead core 4a includes a plurality of bead wires whose periphery is covered with rubber. The bead wire is formed of a steel cord. The steel cord can be made of, for example, steel monofilament or stranded wire. In addition, you may use an organic fiber, carbon fiber, etc. as a bead wire.

[Carcass 5]
The carcass 5 extends between the pair of bead portions 1c, more specifically, between the bead cores 4a of the pair of bead members 4, and extends in a toroidal shape. The carcass 5 has at least a radial structure.

  Further, the carcass 5 includes one or more carcass plies 5a in which carcass cords are arranged at an angle of, for example, 75 ° to 90 ° with respect to the tire circumferential direction C (see FIG. 4). ing. The carcass ply 5a includes a ply body portion positioned between the pair of bead cores 4a, and a ply folding portion that is folded from the inside to the outside in the tire width direction A around the bead core 4a at both ends of the ply body portion. ing. A bead filler 4b extending from the bead core 4a to the outer side in the tire radial direction B is disposed between the ply main body portion and the ply folded portion. As the carcass cord constituting the carcass ply 5a, a polyester cord is employed in this embodiment, but other than this, an organic fiber cord such as nylon, rayon, aramid, or a steel cord may be employed if necessary. Also, the number of carcass plies 5a may be two or more.

[Belt 6]
The belt 6 includes one or more (in this embodiment, five) belt layers disposed on the outer side in the tire radial direction B with respect to the crown portion of the carcass 5. Specifically, as shown in FIG. 3, the belt 6 of the present embodiment includes an inclined belt 6a and a circumferential belt 6b.

  As shown in FIG. 3, the inclined belt 6 a includes one or more (in this embodiment, two) inclined belt layers disposed on the outer side in the tire radial direction B with respect to the crown portion of the carcass 5. . More specifically, the inclined belt 6a of the present embodiment includes a first inclined belt layer 6a1 laminated on the outer surface of the carcass 5 in the tire radial direction B, and the tire radial direction of the first inclined belt layer 6a1. 2nd inclined belt layer 6a2 laminated | stacked on the outer side of B. Each of the first inclined belt layer 6a1 and the second inclined belt layer 6a2 is a belt ply in which steel cords as metal belt cords are inclined at an angle of 10 ° to 40 ° with respect to the tire circumferential direction C (see FIG. 4). Formed from. The two belt plies are stacked with the belt cords inclined in different directions. Therefore, the belt cords cross each other between the belt plies, the belt rigidity is enhanced, and the substantially full width of the tread portion 1a can be reinforced by the tagging effect. In the present embodiment, the second inclined belt layer 6a2 positioned on the outer side in the tire radial direction B is formed narrower than the first inclined belt layer 6a1 positioned on the inner side in the tire radial direction B. Therefore, in the present embodiment, the first inclined belt layer 6a1 positioned on the inner side in the tire radial direction B extends to the outer side in the tire width direction A than the second inclined belt layer 6a2 positioned on the outer side in the tire radial direction B. Exist.

  However, the first inclined belt layer positioned inside the tire radial direction B may be formed narrower than the second inclined belt layer positioned outside the tire radial direction B. In other words, the second inclined belt layer positioned outside the tire radial direction B may extend to the outer side in the tire width direction A than the first inclined belt layer positioned inside the tire radial direction B.

  As shown in FIG. 3, the circumferential belt 6 b includes one or more (three layers in this embodiment) circumferential belt layers disposed outside the tire radial direction B with respect to the inclined belt 6 a. . More specifically, the circumferential belt 6b includes a first circumferential belt layer 6b1 laminated on the outer surface in the tire radial direction B of the second inclined belt layer 6a2 of the inclined belt 6a, and the first circumferential belt 6b. The second circumferential belt layer 6b2 laminated on the outer side in the tire radial direction B of the layer 6b1, and the third circumferential belt layer 6b3 laminated on the outer side in the tire radial direction B of the second circumferential belt layer 6b2. And. Each of the first circumferential belt layer 6b1, the second circumferential belt layer 6b2, and the third circumferential belt layer 6b3 has a nylon cord as an organic fiber belt cord of 10 ° with respect to the tire circumferential direction C (see FIG. 4). In the following, the belt ply is preferably wound in a spiral around the tire rotation axis at an angle of 5 ° or less.

  The first circumferential belt layer 6b1 overlaps the tire radial direction B in the entire region in the tire width direction A of the first inclined belt layer 6a1. More specifically, the length in the tire width direction A of the first circumferential belt layer 6b1 of the present embodiment is substantially equal to the length in the tire width direction A of the first inclined belt layer 6a1, and both sides of the tire width direction A are respectively Thus, the belt end of the first inclined belt layer 6a1 and the belt end of the first circumferential belt layer 6b1 are overlapped in the tire radial direction B so that the positions in the tire width direction A are substantially equal.

  The second circumferential belt layer 6b2 overlaps the tire radial direction B in the entire region in the tire width direction A of the first circumferential belt layer 6b1. More specifically, the length in the tire width direction A of the second circumferential belt layer 6b2 of the present embodiment is longer than the length in the tire width direction A of the first circumferential belt layer 6b1. The positions of the belt ends on both sides in the tire width direction A of the second circumferential belt layer 6b2 are further outside in the tire width direction A than the belt ends in the tire width direction A of the first circumferential belt layer 6b1. Thus, it is piled up in the tire radial direction B.

  The third circumferential belt layer 6b3 is laminated on the outer side in the tire radial direction B of the second circumferential belt layer 6b2 only at the positions of both end portions in the tire width direction A of the second circumferential belt layer 6b2. More specifically, two third circumferential belt layers 6b3 are arranged at different positions in the tire width direction A, and one third circumferential belt layer 6b3 is a tire width of the second circumferential belt layer 6b2. It is laminated on the outer side in the tire radial direction B with respect to one end portion in the direction A. The other third circumferential belt layer 6b3 is laminated on the outer side in the tire radial direction B with respect to the other end portion in the tire width direction A of the second circumferential belt layer 6b2. Further, each third circumferential belt layer 6b3 has a position of the belt end on the outer side in the tire width direction A in the tire width direction A and the position of the belt end in the tire width direction A of the second circumferential belt layer 6b2. It is laminated | stacked on the 2nd circumferential belt layer 6b2 so that it may become substantially equal.

  In addition, although the circumferential belt 6b of this embodiment is comprised by the three-layer circumferential belt layer arrange | positioned on the outer side of the tire radial direction B with respect to the inclination belt 6a, it is not restricted to this structure, 2 It is good also as a circumferential belt which consists of a circumferential belt layer of four layers or less. Further, the length relationship between the plurality of circumferential belt layers in the tire width direction A, the length relationship between the inclined belt layers and the length in the tire width direction A, the positional relationship between the belt ends of the circumferential belt layers, the circumferential belt The positional relationship of the belt ends between the layer and the inclined belt layer, etc. is not limited to the configuration of the present embodiment, and can be appropriately designed according to desired performance, and is not limited to the belt structure of the present embodiment. .

[Tread rubber 7 and side rubber 8]
The tread rubber 7 is disposed outside the tire radial direction B of the carcass 5 so as to cover the belt layer of the belt 6. The tread rubber 7 constitutes an outer surface of the tread portion 1a in the tire radial direction B (hereinafter referred to as “tread outer surface”), and the tread outer surface has a tire circumferential direction C (see FIG. 4). ) Extending in the tire width direction A, and a tread pattern including a width direction groove (not shown) extending in the tire width direction A is formed. The side rubber 8 constitutes the outer surface of the sidewall portion 1b in the tire width direction A, and is formed integrally with the tread rubber 7 described above.

[Inner liner 9]
The inner liner 9 is laminated on the inner surface of the carcass 5 and is formed of butyl rubber having low air permeability. The butyl rubber means butyl rubber and halogenated butyl rubber which is a derivative thereof. The sound damper 3 is fixed to the inner liner 9 with a double-sided adhesive tape, an adhesive, or the like. Therefore, in the inner liner 9, the region where the sound damper 3 is fixed is also a low butyl compound region in which the amount of butyl rubber is lower than the region where the sound absorber 3 is not fixed in order to improve adhesion. Good.

[Predetermined region N covered by the sound control body 3 on the tire inner surface]
Next, with reference to FIG. 2, FIG. 3, the detail of the predetermined area | region N covered with the noise suppression body 3 among tire inner surfaces is demonstrated. The predetermined region N on the inner surface of the tire is a region straddling the belt end position X on the inner surface of the tire that overlaps the belt end in the tire width direction A of the innermost belt layer in the radial direction of the belt 6 in the tire radial direction B and extends in the tire width direction A is there. Here, the “radial innermost belt layer” of the belt 6 means a belt layer located on the innermost side in the tire radial direction B among one or more belt layers in the belt 6. Therefore, the radially innermost belt layer in the present embodiment is the first inclined belt layer 6 a 1 of the belt 6. The belt end in the tire width direction A of the radially innermost belt layer in the present embodiment is the belt end 13 in the tire width direction A of the first inclined belt layer 6a1.

  In this manner, the sound damper 3 covers the tire inner surface so as to straddle the belt end position X in the tire width direction A. On the other hand, the sound damper 3 is not fixed to the belt end position X on the inner surface of the tire. That is, the noise control body 3 covers the belt end position X on the tire inner surface without being fixed to the belt end position X on the tire inner surface. By covering the inner surface of the tire with the sound damper 3, it is possible to exhibit the cavity resonance energy reduction performance due to relaxation, absorption, conversion to another energy (for example, thermal energy), and the like. Even if the noise control body 3 is arranged so as to cover the belt end position X, if the structure is not fixed to the belt end position X, it is compared with the configuration fixed to the belt end position X in the radial direction. Heat generated in the vicinity of the belt end of the innermost belt layer (the belt end 13 of the first inclined belt layer 6a1 in this embodiment) is generated between the two formed by the tire inner surface and the sound damping body 3 not being fixed. Heat can be easily radiated to the tire lumen 101 (see FIG. 1 and the like) through the gap. Therefore, it is possible to achieve the tire 1 that can suppress the reduction of the heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting the cavity resonance energy reduction performance.

  The noise control body 3 may be fixed to the tire inner surface at an arbitrary position outside the belt end position X in the tire width direction A in the predetermined region N. However, the sound damper 3 of the present embodiment covers the tire inner surface without being fixed to the tire inner surface in the outer region M1 outside the belt end position X in the tire width direction A in the predetermined region N. Yes. That is, the sound control body 3 of the present embodiment covers not only the belt end position X but also the outer region M1 outside the belt end position X in the tire width direction A on the tire inner surface. Furthermore, the sound damping body 3 of the present embodiment is not only fixed to the belt end position X, but also not fixed to the tire inner surface in the outer region M1. With this configuration, heat generated near the belt end of the radially innermost belt layer (the belt end 13 of the first inclined belt layer 6a1 in this embodiment) is formed at the position of the outer region M1. Further, it is easier to radiate heat to the tire lumen 101 (see FIG. 1 and the like) through the gap between the sound control body 3 and the tire inner surface. That is, it is possible to realize the tire 1 that can further suppress the deterioration of the heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting the cavity resonance energy reduction performance.

  Further, the predetermined region N of the present embodiment includes a region extending over the belt width position A on one side in the tire width direction A and a belt edge position X on the other side in the tire width direction A. And a region straddling. That is, in this embodiment, the outer ends 41 on both sides in the tire width direction A of the noise damper 3 are the belt ends 13 on both sides in the tire width direction A of the first inclined belt layer 6a1 as the radially innermost belt layer. Rather than outside in the tire width direction A. Hereinafter, for convenience of explanation, the belt end position X on one side in the tire width direction A is referred to as “first belt end position X1”, and the belt end position X on the other side in the tire width direction A is referred to as “second belt end position”. X2 ".

  The outer region M1 of the present embodiment includes a first outer region M1a on the outer side in the tire width direction A from the first belt end position X1, and a second outer region on the outer side in the tire width direction A from the second belt end position X2. And M1b. And the sound-damping body 3 of this embodiment has covered the tire inner surface, without adhering to a tire inner surface in 1st outer side area | region M1a. Further, the sound damping body 3 of the present embodiment covers the tire inner surface without being fixed to the tire inner surface in the second outer region M1b. In this way, by providing the outer regions M1 to which the sound damping body 3 is not fixed on both sides in the tire width direction A, in the vicinity of the belt ends on both sides of the radially innermost belt layer (in this embodiment, the first inclined belt layer 6a1). In the vicinity of the belt end 13), it is possible to suppress a decrease in the heat dissipation performance in the vicinity of the belt end of the radially innermost belt layer while exhibiting the cavity resonance energy reduction performance.

  Furthermore, the sound damper 3 of the present embodiment is fixed to the inner surface 31 of the tread, and the outer ends 41 on both sides in the tire width direction A are the outermost belt layers in the width direction of the belt 6 in the tire width direction A. It is located further outside in the tire width direction A than the belt end located outside. Here, the “width direction outermost belt layer” of the belt 6 is a belt layer in which the belt end in the tire width direction A is located on the outermost side in the tire width direction A among the one or more belt layers in the belt 6. means. Therefore, the outermost belt layer in the width direction in the present embodiment is the third circumferential belt layer 6 b 3 of the belt 6. And the belt end located outside the tire width direction A of the width direction outermost belt layer in the present embodiment is a belt end Q located outside the tire width direction A of the third circumferential belt layer 6b3.

  By adopting such a configuration of the noise damper 3, the tire lumen is increased while increasing the area of the tire inner surface covered by the noise absorber 3 as compared with a configuration in which the noise absorber is provided only at the center in the tire width direction. The volume of the sound control body 3 at 101 can be increased. Therefore, cavity resonance energy can be reduced efficiently. On the other hand, as described above, the region including the outer ends 41 on both sides in the tire width direction A of the sound damping body 3 covers the tire inner surface but does not adhere to the heat dissipation performance of the tire 1. Can be increased. In particular, in the present embodiment, the region including the outer ends 41 on both sides of the sound damper 3 in the tire width direction A covers the belt end position X on the tire inner surface, but is not fixed to the belt end position X. That is, since the sound damping body 3 of the present embodiment covers a wide region including the belt end position X on the tire inner surface, the cavity resonance energy can be efficiently reduced, and the belt end position X that easily generates heat can be obtained. Since it is not fixed, it is possible to efficiently suppress a decrease in heat dissipation performance.

  Further, the sound damping body 3 of the present embodiment is fixed to the tire inner surface in a part of the central region M2 sandwiched between the first outer region M1a and the second outer region M1b in the predetermined region N. . The central region M2 is a part of the tread inner surface 31.

  Hereinafter, further details of the sound control body 3 of the present embodiment will be described.

  The sound damping body 3 of the present embodiment is a belt-like member that extends over substantially the entire circumferential region in the tire circumferential direction C (see FIG. 4), and at any position in the tire circumferential direction C (see FIG. 4). In the cross-sectional view in the tire width direction (see FIG. 2 and the like), they have substantially the same cross-sectional outer shape. Specifically, the sound damping body 3 of the present embodiment has a horizontally long flat shape having a maximum width W1 larger than the maximum thickness T1 in a tire width direction cross-sectional view (see FIG. 2 and the like). In addition, the sound control body 3 of the present embodiment has a symmetrical shape with respect to the tire equatorial plane CL. The “thickness” and “width” of the sound control body 3 are measured in a state where the sound control body 3 is attached to the tire 1 and before the rim assembly (normal temperature and normal pressure). Means the thickness measured in the direction perpendicular to the inner surface of the opposing tire, and “width” means the width measured in the tire width direction A. That is, the above-mentioned “maximum thickness T1” means the maximum value of the thickness measured in the direction perpendicular to the opposing tire inner surface, and “maximum width W1” is the maximum width measured in the tire width direction A. Mean value. In addition, the maximum thickness T1 of the sound control body 3 of this embodiment is set to 5 mm to 45 mm.

  In the tire width direction A, the sound damping body 3 of the present embodiment includes a fixed region D1 and a non-fixed region D2. The fixing region D1 of the sound damper 3 is a region that is fixed to the tire inner surface and covers the tire inner surface. The non-adhesion region D2 of the sound control body 3 is a region that is continuous with the adhesion region D1 and the tire width direction A and covers the tire inner surface without being adhered to the tire inner surface. The non-adhesion region D2 of the sound damper 3 of the present embodiment covers the outer region M1 of the predetermined region N on the tire inner surface.

  Here, the maximum thickness T2 of the sound damper 3 in the non-adhesion region D2 is thinner than the minimum thickness T3 of the sound absorber 3 in the adhesion region D1. By doing in this way, the non-adhesion area | region D2 can be made thinner than the adhesion area | region D1, and the fall of the thermal radiation performance of the tire 1 by providing the non-adhesion area | region D2 can be suppressed further. In addition, since the thickness in the non-adhesion area | region D2 of the noise suppression body 3 in this embodiment is uniform, the said thickness is the maximum thickness T2 in the arbitrary positions of the tire width direction A of the non-adhesion area | region D2. Become. Moreover, since the thickness in the adhering region D1 of the sound damper 3 in the present embodiment is also uniform, the thickness becomes the minimum thickness T3 at an arbitrary position in the tire width direction A of the adhering region D1. Therefore, the maximum thickness T1 of the sound damper 3 of the present embodiment is equal to the minimum thickness T3 that is the thickness of the sound damper 3 in the fixing region D1.

  Further, the sound control body 3 of the present embodiment is fixed to the tread inner surface 31. More specifically, the sound damping body 3 of the present embodiment is fixed to a region of the tread inner surface 31 that includes a position that intersects the tire equator plane CL. By fixing the sound damper 3 to the tread inner surface 31, the sound damper 3 can be pressed against the tread inner surface 31 by centrifugal force acting toward the outer side in the tire radial direction B even when the tire 1 rotates at high speed. it can. Therefore, it becomes easy to effectively restrain the movement of the sound control body 3. That is, by fixing the sound damping body 3 to the tread inner surface 31, not only destruction of the sound damping body 3 itself but also unfixing can be suppressed with a smaller fixing force. In particular, if the sound damper 3 is fixed to a region of the tread inner surface 31 that includes a position that intersects the tire equator plane CL, the movement of the sound damper 3 can be more effectively restrained. For this reason, it is possible to further suppress the destruction and unfixing of the sound control body 3 itself.

  Further, the band-shaped member as the sound damping body 3 of the present embodiment is, for example, linearly formed, and then curved in a circular arc shape in the tire circumferential direction C (see FIG. 4) along the tread inner surface 31. It is fixed to the tread inner surface 31 using a fixing member such as a double-sided adhesive tape or an adhesive. Both end portions in the tire circumferential direction C (see FIG. 4) of the belt-like member as the sound control body 3 may be separated by a slight gap and are continuous over the entire region in the tire circumferential direction C (see FIG. 4). Thus, both ends may be joined together. Moreover, you may make the strip | belt-shaped member as the noise suppression body 3 spirally circulate along the tire circumferential direction C (refer FIG. 4), shifting in the tire width direction A. FIG. Furthermore, a plurality of belt-like members as the sound control body 3 may be intermittently arranged with a gap in the tire circumferential direction C (see FIG. 4). Furthermore, a plurality of belt-like members as the sound control body 3 may be arranged in the tire width direction A. The sound damping body 3 of the present embodiment is composed of a single belt-like member, and is continuous in the tire circumferential direction C (see FIG. 4) so as to be continuous over the entire region in the tire circumferential direction C (see FIG. 4). It is being fixed to the tread inner surface 31 in the state which faced both end surfaces.

  Next, the further detail of the external shape in the tire width direction cross-sectional view (refer FIG. 2 etc.) of the noise suppression body 3 of this embodiment is demonstrated. The sound damping body 3 of the present embodiment includes a facing surface 3a facing the tire inner surface and a free surface 3b opposite to the facing surface 3a. The facing surface 3a of the sound damper 3 of the present embodiment includes the facing fixing surface 3a1 fixed to the tread inner surface 31 in the fixing region D1 described above. Further, the facing surface 3a of the sound damper 3 of the present embodiment covers and covers the tread inner surface 31 and part of the sidewall inner surface 32 in the non-fixed region D2 described above. An opposing non-fixed surface 3a2 that is not fixed to the tire inner surface including the inner surface 31 and the sidewall inner surface 32 is provided. Opposing non-adhering surfaces 3a2 are provided on both sides of the opposing adhering surface 3a1 in the tire width direction A, respectively. The opposing fixing surface 3a1 and the opposing non-fixing surface 3a2 are connected via a step surface 3a3 extending in the thickness direction of the sound damper 3. Thus, by providing a step between the opposing non-fixed surface 3a1 and the counter non-fixed surface 3a2, the counter non-fixed surface 3a2 can be easily moved away from the tire inner surface, and a gap is formed between the counter non-fixed surface 3a2 and the tire inner surface. It can be easily secured. That is, it becomes easy to radiate heat from the tire 1 through the gap, and the deterioration of the heat radiating performance of the tire 1 due to the provision of the non-fixed region D2 can be further suppressed.

  In order to keep the opposed non-fixed surface 3a2 away from the opposed inner surface 34 of the tire inner surface to which the opposed non-fixed surface 3a2 is opposed, the configuration is not limited to the above-described stepped surface 3a3. The opposing non-fixed surface extends in an inclined manner with respect to the counter fixed surface in a direction away from the counter inner surface 34 of the tire inner surface toward the outer side in the tire width direction A. It may be a surface.

  Further, the opposing fixing surface 3a1 of the present embodiment is disposed at a position intersecting with the tire equatorial plane CL. Further, the center position in the tire width direction A of the opposing fixing surface 3a1 of the present embodiment is aligned with the tire equatorial plane CL.

  The free surface 3b of the sound damper 3 of the present embodiment is constituted by a flat portion 3b1 extending along the tire inner surface. In addition, the facing surface 3 a and the free surface 3 b of the sound damper 3 of the present embodiment extend in the thickness direction of the sound damper 3 and are connected by a side end surface 3 c that forms the outer end 41 of the sound damper 3. ing.

  Moreover, the non-adhesion area | region D2 located in the both sides of the tire width direction A of the noise suppression body 3 of this embodiment is not being fixed to the tire inner surface over the whole region of the tire circumferential direction C (refer FIG. 4). On the other hand, the adhering region D1 located at the center in the tire width direction A of the sound damper 3 of the present embodiment is adhering to the tire inner surface over the entire region in the tire circumferential direction C (see FIG. 4).

  Here, the sound damper 3 of the present embodiment is not only fixed to the opposed inner surface 34 of the tire inner surface in the non-adhered region D2, but is at least partially spaced from the opposed inner surface 34. In other words, a gap S is formed between the sound damper 3 and the opposed inner surface 34 in the non-fixed region D2. In other words, a gap S is formed between the sound control body 3 and the tire inner surface in the outer region M1. More specifically, the sound damper 3 of the present embodiment is completely separated from the opposed inner surface 34 in the non-fixed region D2 by the above-described step surface 3a3.

  The sound damper 3 may be in non-adhering contact with the tire inner surface in the non-adhering region D2, but the sound absorber 3 can be separated from the tire inner surface in the non-adhering region D2 as in the present embodiment. In this case, the heat dissipation efficiency of the tire 1 can be increased as compared with the contacting configuration. And if the noise suppression body 3 is completely spaced apart from the tire inner surface in the non-adhesion region D2 as in this embodiment, the heat dissipation efficiency of the tire 1 can be further increased.

  FIG. 4 is a development view of the inner surface of the tire 1. As shown in FIG. 4, the convex part 12 is formed in the tire inner surface. More specifically, the convex portion 12 is a rib that extends in a direction inclined with respect to the tire circumferential direction C and protrudes toward the tire lumen 101 (see FIG. 1). In addition, the rib as the convex part 12 of this embodiment is inclined not only in the tire circumferential direction C but also in the tire width direction A. The ribs as the convex portions 12 are separately provided on both sides in the tire width direction A. In other words, a region where the ribs as the convex portions 12 are not formed is provided in the central portion of the tire inner surface in the tire width direction A. Further, a plurality of ribs as the convex portions 12 provided on both sides in the tire width direction A are arranged at predetermined intervals in the tire circumferential direction C over the entire tire circumferential direction C. Further, the rib as the convex portion 12 located on one side in the tire width direction A extends substantially in parallel with the rib as the convex portion 12 located on the other side in the tire width direction A. The height of the rib as the convex portion 12 can be set to 1 mm to 5 mm, for example. Note that the tire 1 shown in FIGS. 1 to 3 is drawn with the ribs as the convex portions 12 described above omitted.

  As shown in FIG. 4, the fixing region D1 of the sound damping body 3 of the present embodiment is fixed to the region of the tire inner surface where the rib as the convex portion 12 is not formed in the center portion in the tire width direction A. Has been. Therefore, compared with the area | region in which the rib is formed, the fixation area of the opposing fixation surface 3a1 and a tire inner surface can be ensured large. Therefore, the fixing strength of the sound damper 3 can be improved, and peeling of the sound damper 3 from the tire inner surface can be suppressed.

  The non-adhesion region D2 of the sound damping body 3 of the present embodiment is opposed to a region provided with ribs as the convex portions 12 on the tire inner surface. That is, the ribs as the convex portions 12 are formed on the facing inner surface 34 of the tire inner surface, where the sound damping body 3 faces in the non-fixed region D2. In the non-adhering region D2, a gap S is formed around the rib as the convex portion 12 because the rib as the convex portion 12 is interposed between the sound damper 3 and the opposed inner surface 34. The More specifically, in this embodiment, the gap S between the adjacent ribs in the tire circumferential direction C is the gap S. In this way, by providing the convex portion 12 that can hold the gap S between the sound damper 3 and the opposed inner surface 34 in the non-adhesion region D2, not only when there is no rotation, but also a high centrifugal force is applied. Even at the time of rotation and tire deformation, at least a part of the sound damper 3 can be more reliably separated from the opposed inner surface 34 of the tire inner surface in the non-adhering region D2. Therefore, not only when there is no rotation but also when rotating at high speed, a decrease in the heat dissipation performance of the tire can be more reliably suppressed, and the durability of the tire 1 can be further improved.

  In addition, although the convex part 12 shown to this embodiment is a rib inclined with respect to the tire circumferential direction C, the convex part 12 is not restricted to this structure. The convex part 12 is good also as a rib extended in the tire circumferential direction C, for example. However, in the non-adhesion region D2, it is preferable that the gap S between the sound control body 3 and the opposing inner surface 34 of the tire inner surface communicate with the tire lumen 101 (see FIG. 1). Therefore, it is preferable to use ribs that are inclined with respect to the tire circumferential direction C as in the present embodiment, a plurality of protrusions formed on the tire inner surface, and the like. With such a convex portion 12, in the non-fixed region D <b> 2, the gap S formed between the sound damper 3 and the opposed inner surface 34 communicates with the tire lumen 101 on the outer side in the tire width direction A. can do. In particular, as in the present embodiment, if the convex portion 12 is configured by ribs that are inclined with respect to the tire circumferential direction C and the tire width direction A, the air flow generated in the tire lumen 101 during tire rotation (for example, FIG. 4), the air in the gap S is easily released into the tire lumen 101, and the heat dissipation efficiency of the tire 1 in the non-fixed region D2 can be further increased.

  Further, in the present embodiment, in the non-adhesion region D2, the sound damping body 3 is configured to contact the convex portion 12 only when the tire 1 rotates at a high speed. The thickness of the non-adhering region D2 is equal to or greater than the thickness of the fixing region D1 of the sound damper, and the sound absorber is in contact with the convex portion 12 in the non-adhering region D2 even when there is no rotation. The gap S may be formed between the two. However, like the sound control body 3 of the present embodiment, when the tire 1 is not rotating, the tire 1 is not in contact with the convex portion 12 in the non-adhering region D2, and is largely separated from the tire inner surface. In the non-adhering region D2, it is preferable to approach the inner surface of the tire and come into contact with the convex portion 12. In this way, the heat dissipation efficiency of the tire 1 in the non-adhering region D2 can be increased even when, for example, no rotation is performed immediately after high speed rotation.

  Next, a tire 21 as a modified example of the tire 1 of the present embodiment will be described with reference to FIG. The tire 21 shown in FIG. 5 differs from the tire 1 of the present embodiment in the shape of the sound control body, but the other configurations are the same. Here, differences will be mainly described, and description of common configurations will be omitted.

  The tire 21 shown in FIG. The sound control body 23 includes a facing surface 23a that faces the tread inner surface 31 of the tire inner surface, and a free surface 23b that is located on the opposite side of the facing surface 23a. The shape of the facing surface 23 a of the sound damper 23 is the same as the shape of the facing surface 3 a of the sound damper 3 described above, but the shape of the free surface 23 b is different from the shape of the free surface 3 b of the sound damper 3. ing.

  The free surface 23b of the noise control body 23 shown in FIG. 5 includes a flat portion 23b1 extending along the tire inner surface, and a mountain portion 23b2 projecting inward in the tire radial direction B from the flat portion 23b1. I have. Thus, if the peak part 23b2 is provided in the free surface 23b, the surface area of the free surface 23b can be enlarged compared with the structure only of a flat part. Therefore, the area where the sound control body 23 comes into contact with the air in the tire lumen 101 is increased, the cooling efficiency of the sound control body 23 is increased, and as a result, the heat dissipation performance of the tire 1 can be improved. From the viewpoint of cooling efficiency, it is preferable to provide a plurality of (four in the example of FIG. 5) peak portions 23b2 on the free surface 23b.

  Further, the free surface 23b in the fixing region D1 is provided with a flat portion 23b1 and a peak portion 23b2. In the fixing region D1, the thickness of the noise damper 23 at the position of the flat portion 23b1 (“T3 in FIG. 5). Is smaller than the thickness of the sound control body 23 at the position of the peak portion 23b2 (see “T1” in FIG. 5). Further, the thickness of the sound damper 23 at the position of the flat portion 23b1 in the fixed region D1 is thicker than the maximum thickness T2 of the noise suppressor 23 in the non-adhered region D2. Note that the thickness of the non-adhering region D2 of the sound damper 23 shown in FIG. 5 is substantially constant regardless of the position in the tire width direction A. Therefore, for the sound damping body 23 shown in FIG. 5, the thickness at an arbitrary position in the tire width direction A of the non-fixed region D2 is the above-described maximum thickness T2. Further, in the sound damping body 23 shown in FIG. 5, the thickness of the sound damping body 23 at the position of the flat portion 23b1 in the fixing region D1 is the minimum thickness T3 of the noise suppressing body 23 in the fixing region D1. Further, in the sound damping body 23 shown in FIG. 5, the thickness of the sound damping body 23 at the position of the peak portion 23b2 in the fixing region D1 is the maximum thickness of the noise suppressing body 23 in the fixing region D1. This is the maximum thickness T1 in all 23 regions.

  In other words, the provision of the mountain portion 23b2 not only increases the surface area but also increases the thickness of the sound control body 23 at the position of the mountain portion 23b2, compared to the configuration of only the flat portion 23b1, thereby increasing the tire thickness. The volume of the sound control body 23 in the lumen 101 can be secured, and the cavity resonance energy reduction performance is enhanced. The relationship between the thickness of the sound damper 23 at the position of the flat portion 23b1 in the fixed region D1 (see “T3” in FIG. 5) and the maximum thickness T2 of the sound absorber 23 in the non-adhered region D2 is The relationship between the thicknesses T2 and T3 (see FIG. 2) of the sound control body 3 described above is the same, and the operational effects thereof are also the same.

  The pneumatic tire and assembly according to the present invention are not limited to the specific configuration shown in the above-described embodiment, and various modifications and changes can be made without departing from the scope of the claims. For example, a plurality of peak portions 23b2 of the sound control body 23 shown in FIG. 5 are arranged at intervals in the tire width direction A and each extend in the tire circumferential direction C. However, the configuration is not limited thereto. A plurality of tires may be arranged in the tire circumferential direction C (see FIG. 4) at intervals, and each may extend in the tire width direction A. Moreover, it is good also as a peak part scattered in the tire width direction A and the tire circumferential direction C.

  The present invention relates to a pneumatic tire and an assembly.

1: pneumatic tire, 1a: tread portion, 1b: sidewall portion,
1c: bead part, 2: rim, 2a: rim body, 2a1: rim seat part,
2a2: rim flange part, 2b: disc, 3: sound damping body, 3a: facing surface,
3a1: opposite fixing surface (facing surface), 3a2: opposing non-fixing surface (facing surface),
3a3: step surface, 3b: free surface, 3b1: flat part (free surface),
3c: side end surface, 4: bead member, 4a: bead core,
4b: bead filler, 5: carcass, 5a: carcass ply,
6: Belt, 6a: Inclined belt,
6a1: first inclined belt layer (radially innermost belt layer),
6a2: second inclined belt layer, 6b: circumferential belt,
6b1: first circumferential belt layer, 6b2: second circumferential belt layer,
6b3: third circumferential belt layer (width direction outermost belt layer), 7: tread rubber,
7a: circumferential groove, 8: side rubber, 9: inner liner, 12: convex part,
13: Belt end of the first inclined belt layer (belt end of the radially innermost belt layer),
21: Pneumatic tire, 23: Sound control body, 23a: Opposing surface,
23b: free surface, 23b1: flat part (free surface),
23b2: Mountain (free surface), 31: Tread inner surface (tire inner surface),
32: Side wall inner surface (tire inner surface), 33: Bead inner surface (tire inner surface),
34: opposing inner surface (tire inner surface), 41: outer end, 100: assembly,
101: tire lumen, A: tire width direction, B: tire radial direction,
C: tire circumferential direction, D1: damping region fixing area, D2: damping member non-fixing area,
M1: outer region, M1a: first outer region, M1b: second outer region,
M2: central area, N: predetermined area,
P1, P2: planes parallel to the tire radial direction, passing through the outermost belt end on both sides in the tire width direction of the belt,
Q: Belt end of the third circumferential belt layer (belt end of the outermost belt layer in the width direction),
S: gap, T1: maximum thickness of the sound control body,
T2: Maximum thickness of the non-adhering region of the sound damper, T3: Minimum thickness of the immobilizing region of the sound absorber
W1: Maximum width of the sound control body, X: Belt end position, X1: First belt end position,
X2: Second belt end position, CL: Tire equatorial plane

Claims (9)

A toroidal carcass straddling between a pair of bead parts;
One or more belt layers disposed on the outer side in the tire radial direction with respect to the carcass;
A tread rubber disposed outside the carcass in the tire radial direction so as to cover the one or more belt layers, and a pneumatic tire comprising:
It is fixed to the inner surface of the tread located on the back side of the tread rubber among the inner surface of the tire, and includes a noise control body covering a predetermined region of the inner surface of the tire,
The one or more belt layers include a radially innermost belt layer positioned on the innermost side in the tire radial direction,
The predetermined region of the tire inner surface is a region straddling a belt end position of the tire inner surface that overlaps with a belt end in the tire width direction of the radial innermost belt layer in the tire radial direction, and straddles the tire width direction,
The pneumatic tire is a pneumatic tire that covers the belt end position of the tire inner surface without being fixed to the belt end position of the tire inner surface.   The sound damping body covers the tire inner surface without being fixed to the tire inner surface in an outer region outside the belt end position in the tire width direction in the predetermined region. The described pneumatic tire. The predetermined region includes a region straddling the belt end position on one side in the tire width direction in the tire width direction, and a region straddling the belt end position on the other side in the tire width direction in the tire width direction,
The outer region includes a first outer region on the outer side in the tire width direction from the belt end position on the one side, and a second outer region on the outer side in the tire width direction from the belt end position on the other side,
The sound control body is
In the first outer region, the tire inner surface is covered without being fixed to the tire inner surface,
The pneumatic tire according to claim 2, wherein the second outer region covers the tire inner surface without being fixed to the tire inner surface. Of the noise control body, a region covering the tire inner surface without being fixed to the tire inner surface in the tire width direction is defined as a non-fixed region, and the tire is fixed to the tire inner surface in the tire width direction. When the area covering the inner surface is a fixed area,
The pneumatic tire according to claim 2 or 3, wherein a maximum thickness of the noise damper in the non-adhering region is thinner than a minimum thickness of the noise absorber in the adhering region. The sound damping body includes a facing surface facing the tire inner surface, and a free surface located on the opposite side of the facing surface,
5. The pneumatic tire according to claim 4, wherein the free surface includes a flat portion extending along the tire inner surface and a mountain portion protruding toward an inner side in a tire radial direction from the flat portion. The free surface in the fixed region is provided with the flat portion and the peak portion,
In the fixed region, the thickness of the noise damper at the position of the flat portion is smaller than the thickness of the noise damper at the position of the peak portion, and the thickness of the noise suppressor in the non-fixed region is The pneumatic tire according to claim 5, wherein the pneumatic tire is thicker than the maximum thickness.   The pneumatic tire according to any one of claims 2 to 6, wherein a gap is formed between the sound control body and the tire inner surface in the outer region.   The pneumatic tire according to any one of claims 1 to 7, wherein the sound control body is fixed to a region including a position intersecting with a tire equator plane on the inner surface of the tread.   An assembly comprising the pneumatic tire according to any one of claims 1 to 8, and a rim to which the pneumatic tire is attached.

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