WO2020121571A1

WO2020121571A1 - Pneumatic radial tire for passenger vehicles

Info

Publication number: WO2020121571A1
Application number: PCT/JP2019/027043
Authority: WO
Inventors: 勲桑山
Original assignee: 株式会社ブリヂストン
Priority date: 2018-12-13
Filing date: 2019-07-08
Publication date: 2020-06-18
Also published as: JP2020093675A; JP2022164929A

Abstract

This pneumatic radial tire for passenger vehicles is equipped with a carcass which comprises a ply of radially arranged cords extending toroidally across a pair of bead portions, and the cross-sectional width SW (mm) and outer diameter OD (mm) of the tire satisfy a predetermined relational expression. One or more noise suppressors are provided on the inner surface of the tire. The noise suppressors are provided at least on the inner surface of the tire in a shoulder region. The ratio T1/L1 falls within the range of 0.2-0.8 where L1 (mm) is the peripheral length of the noise suppressor along the inner surface of the tire and T1 (mm) is the maximum thickness of the noise suppressor measured in a direction perpendicular to the direction along the inner surface of the tire.

Description

Pneumatic radial tires for passenger cars

The present invention relates to a pneumatic radial tire for passenger cars.

The applicant has proposed various narrow and large-diameter pneumatic radial tires for passenger cars in which the tire cross-section width SW and the tire outer diameter OD have a predetermined relationship (for example, Patent Document 1).

▽Here, for pneumatic radial tires for passenger cars (especially pneumatic radial tires for electric vehicles), reduction of tire noise is required. As one of the tire noises, so-called road noise is known, which produces a sound in a frequency range of 50 to 400 Hz when traveling on a road surface. The main cause of this is resonance vibration (cavity resonance) of air or gas generated in the tire inner cavity. On the other hand, it is known to dispose a noise suppressor made of a sponge material or the like on the inner surface of the tire (for example, Patent Document 2). The noise suppressor can convert vibration energy of air or gas in the tire inner cavity into heat energy, and suppress cavity resonance in the tire inner cavity.

International publication 2012/176476 pamphlet JP 2005-254924 A

However, when the above-mentioned noise damper is provided on the inner surface of the tire in order to improve the noise damping property, heat is accumulated in the noise damper, and the noise damper and the inner surface of the tire are bonded to each other, for example, after running for a long time. In some cases, the durability of the tire is deteriorated by melting the adhesive layer, peeling the noise suppressor from the inner surface of the tire, or easily causing a failure in the tire member. As described above, it is usually difficult to achieve both the noise control property and the tire durability.

Therefore, an object of the present invention is to provide a pneumatic radial tire for passenger cars, which has both noise control and tire durability.

The gist of the present invention is as follows.
In the first aspect, the pneumatic radial tire for passenger cars of the present invention is
A pneumatic radial tire for a passenger vehicle, which comprises a carcass consisting of a ply of a radial arrangement cord, straddling toroidally between a pair of bead portions,
The sectional width SW of the tire is less than 165 (mm), the ratio SW/OD of the sectional width SW (mm) and the outer diameter OD (mm) of the tire is 0.26 or less,
The inner surface of the tire is provided with one or more noise dampers,
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a no-load state, a tire width direction region of the tire width direction center 50% between ground contact ends is defined as a center region, and the center When the tire width direction area of 25% outside the area in the tire width direction is set as the shoulder area,
The noise damper is provided at least on the inner surface of the tire in the shoulder region,
In the tire width direction cross section, when the peripheral length of the noise suppressor along the inner surface of the tire is L1 (mm), the measurement is performed in a direction orthogonal to the direction of the noise suppressor along the inner surface of the tire. When the maximum thickness is T1 (mm), the ratio T1/L1 is characterized by being 0.2 or more and 0.8 or less.
The term “periphery length” as used herein means the total length of peripherals when two or more noise suppressors are provided.

Here, the "rim" is an industrial standard that is effective in regions where tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (The European Tire and Rim). STANDARDS MANUAL of ETRTO, or STANDARDS MANUAL of standard size described in YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States, STANDARDS MANUAL of ETRA , TRA's YEAR BOOK Design Rim) (i.e., the above-mentioned "rim" includes, in addition to the current size, a size that may be included in the industry standard in the future. , The size described as “FUTURE DEVELOPMENTS” in the ETRTO 2013 edition can be mentioned.) However, in the case of a size not listed in the above industrial standards, the width corresponding to the bead width of the tire Refers to the rim.
The "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel in the applicable size and ply rating described in JATMA, etc. In this case, the “specified internal pressure” means the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle in which the tire is mounted. Further, the “maximum load capacity” described later means a load corresponding to the maximum load capacity.

The term "ground contact edge" means both ends in the tire width direction of the ground contact surface that comes into contact with the road surface when the tire is incorporated into a rim, the specified internal pressure is filled, and the maximum load is applied.

In a second aspect, the pneumatic radial tire for passenger cars of the present invention is
A pneumatic radial tire for a passenger vehicle, which comprises a carcass consisting of a ply of a radial arrangement cord, straddling toroidally between a pair of bead portions,
The sectional width SW of the tire is 165 (mm) or more, and the sectional width SW (mm) and the outer diameter OD (mm) of the tire are expressed by a relational expression,
OD (mm)≧2.135×SW (mm)+282.3
The filling,
The inner surface of the tire is provided with one or more noise dampers,
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a no-load state, a tire width direction region of the tire width direction center 50% between ground contact ends is defined as a center region, and the center When the tire width direction area of 25% outside the area in the tire width direction is set as the shoulder area,
The noise damper is provided at least on the inner surface of the tire in the shoulder region,
In the tire width direction cross section, when the peripheral length of the noise suppressor along the inner surface of the tire is L1 (mm), the measurement is performed in a direction orthogonal to the direction of the noise suppressor along the inner surface of the tire. When the maximum thickness is T1 (mm), the ratio T1/L1 is characterized by being 0.2 or more and 0.8 or less.

In a third aspect, the pneumatic radial tire for passenger cars of the present invention is
A pneumatic radial tire for a passenger vehicle, which comprises a carcass consisting of a ply of a radial arrangement cord, straddling toroidally between a pair of bead portions,
The sectional width SW (mm) and outer diameter OD (mm) of the tire are expressed by a relational expression,
OD (mm) ≥-0.0187 x SW (mm) ² +9.15 x SW (mm)-380
The filling,
The inner surface of the tire is provided with one or more noise dampers,
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a no-load state, a tire width direction region of the tire width direction center 50% between ground contact ends is defined as a center region, and the center When the tire width direction area of 25% outside the area in the tire width direction is set as the shoulder area,
The noise damper is provided at least on the inner surface of the tire in the shoulder region,
In the tire width direction cross section, when the peripheral length of the noise suppressor along the inner surface of the tire is L1 (mm), the measurement is performed in a direction orthogonal to the direction of the noise suppressor along the inner surface of the tire. When the maximum thickness is T1 (mm), the ratio T1/L1 is characterized by being 0.2 or more and 0.8 or less.

In the present specification, the “sidewall portion” is the tire width direction outer side of the ground contact end E, and the tire radial direction outer end of the bead portion from the ground contact end E (in the case of having a bead filler, the tire radial direction outer end thereof). In the case of not having a bead filler, it means a tire radial direction region up to the tire radial direction outer end of the bead core.

In the present specification, the "butless portion" means a virtual line extending in the tire radial direction through the ground contact end E in the tire width direction cross-sectional view in which the tire is mounted on the applicable rim, the internal pressure is filled with the tire, and no load is applied. And a virtual line that passes through the tire surface position that is half the length of the peripheral from the ground contact end E to the tire surface position that is the maximum width of the tire and that is perpendicular to the tire inner surface.

According to the present invention, it is possible to provide a pneumatic radial tire for passenger cars, which has both noise control and tire durability.

It is a schematic diagram showing section width SW and outer diameter OD of a tire. FIG. 3 is a cross-sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to an embodiment of the first to third aspects of the present invention. It is a figure which shows typically the contact pressure distribution of the tire of a normal tire size. It is a figure which shows typically the contact pressure distribution of a narrow width and large diameter tire. FIG. 4 is a sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to another embodiment of the first to third aspects of the present invention. FIG. 3 is a sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to another embodiment of the first to third aspects of the present invention. FIG. 6 is a sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to still another embodiment of the first to third aspects of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

<Pneumatic radial tires for passenger cars>
FIG. 1 is a schematic diagram showing a sectional width SW and an outer diameter OD of a tire.
A pneumatic radial tire for passenger cars (hereinafter, also simply referred to as a tire) according to an embodiment of the first aspect of the present invention has a tire sectional width SW of less than 165 (mm), and a tire sectional width SW and an outer diameter. The ratio SW/OD with OD is 0.26 or less, and the shape is narrow and large in diameter. By narrowing the cross-sectional width SW of the tire as compared with the outer diameter OD of the tire, air resistance can be reduced, and by increasing the outer diameter OD of the tire as compared with the cross-sectional width SW of the tire. The rolling resistance can be reduced by suppressing the deformation of the tread rubber near the ground contact surface of the tire, which can improve the fuel economy of the tire. The SW/OD is preferably 0.25 or less, more preferably 0.24 or less.
The above ratio is preferably satisfied when the internal pressure of the tire is 200 kPa or more, more preferably 220 kPa or more, and more preferably 280 kPa or more. Is more preferable. This is because the rolling resistance can be reduced. On the other hand, the above ratio is preferably satisfied when the internal pressure of the tire is 350 kPa or less. This is because the riding comfort can be improved.
Here, from the viewpoint of ensuring the ground contact area, the sectional width SW of the tire is preferably 105 mm or more, more preferably 125 mm or more, and further preferably 135 mm or more in the range satisfying the above ratio. It is preferably 145 mm or more and particularly preferably. On the other hand, the sectional width SW of the tire is preferably 155 mm or less in the range satisfying the above ratio from the viewpoint of reducing the air resistance. Further, from the viewpoint of reducing rolling resistance, the outer diameter OD of the tire is preferably 500 mm or more, more preferably 550 mm or more, and further preferably 580 mm or more in the range satisfying the above ratio. .. On the other hand, from the viewpoint of reducing the air resistance, the outer diameter OD of the tire is preferably 800 mm or less, more preferably 720 mm or less, and further preferably 650 mm or less in the range satisfying the above ratio. It is preferably 630 mm or less, and particularly preferably 630 mm or less. Further, from the viewpoint of reducing rolling resistance, the rim diameter is preferably 16 inches or more, and more preferably 17 inches or more when the sectional width SW and the outer diameter OD of the tire satisfy the above ratio. More preferably, it is 18 inches or more. On the other hand, from the viewpoint of reducing air resistance, the rim diameter is preferably 22 inches or less, and more preferably 21 inches or less when the sectional width SW and the outer diameter OD of the tire satisfy the above ratio. 20 inches or less is more preferable, and 19 inches or less is particularly preferable. Further, the flatness of the tire is more preferably 45 to 70, and further preferably 45 to 65 when the sectional width SW and the outer diameter OD of the tire satisfy the above ratios.
The specific tire size is not particularly limited, but as an example, 105/50R16, 115/50R17, 125/55R20, 125/60R18, 125/65R19, 135/45R21, 135/55R20, 135/60R17. , 135/60R18, 135/60R19, 135/65R19, 145/45R21, 145/55R20, 145/60R16, 145/60R17, 145/60R18, 145/60R19, 145/65R19, 155/45R18, 155/45R21, 155 /55R18, 155/55R19, 155/55R21, 155/60R17, 155/65R18, 155/70R17, 155/70R19.

The tire of one embodiment in the second aspect of the present invention has a tire cross-section width SW of 165 (mm) or more, and the tire cross-section width SW (mm) and outer diameter OD (mm) are expressed by a relational expression,
OD (mm)≧2.135×SW (mm)+282.3
It has a narrow width and a large diameter.
By satisfying the above relational expression, the air resistance can be reduced and the rolling resistance can be reduced, whereby the fuel efficiency of the tire can be improved.
In the second aspect, the sectional width SW and the outer diameter OD of the tire satisfy the above relational expression, and the ratio SW/OD is preferably 0.26 or less, and is 0.25 or less. More preferably, it is more preferably 0.24 or less. This is because the fuel efficiency of the tire can be further improved.
The above relational expression and/or ratio is preferably satisfied when the internal pressure of the tire is 200 kPa or more, more preferably 220 kPa or more, and more preferably 280 kPa or more. More preferably, it is satisfied. This is because the rolling resistance can be reduced. On the other hand, it is preferable that the above relational expressions and/or ratios are satisfied when the internal pressure of the tire is 350 kPa or less. This is because the riding comfort can be improved.
Here, the sectional width SW of the tire is preferably 175 mm or more, and more preferably 185 mm or more, in the range satisfying the above relational expression, from the viewpoint of ensuring the ground contact area. On the other hand, from the viewpoint of reducing the air resistance, the sectional width SW of the tire is preferably 230 mm or less, more preferably 215 mm or less, and more preferably 205 mm or less in the range satisfying the above relational expression. More preferably, it is particularly preferably 195 mm or less. From the viewpoint of reducing rolling resistance, the outer diameter OD of the tire is preferably 630 mm or more, and more preferably 650 mm or more, in the range satisfying the above relational expression. On the other hand, from the viewpoint of reducing air resistance, the outer diameter OD of the tire is preferably 800 mm or less, more preferably 750 mm or less, and even more preferably 720 mm or less in the range satisfying the above relational expression. More preferable. Further, from the viewpoint of reducing rolling resistance, the rim diameter is preferably 18 inches or more, and more preferably 19 inches or more when the sectional width SW and the outer diameter OD of the tire satisfy the above relational expressions. .. On the other hand, from the viewpoint of reducing air resistance, the rim diameter is preferably 22 inches or less, and more preferably 21 inches or less when the tire sectional width SW and the outer diameter OD satisfy the above relational expressions. preferable. Further, when the sectional width SW and the outer diameter OD of the tire satisfy the above relational expressions, the flatness of the tire is preferably 45 to 70, more preferably 45 to 65.
The specific tire size is not particularly limited, but as an example, 165/45R22, 165/55R18, 165/55R19, 165/55R20, 165/55R21, 165/60R19, 165/65R19, 165/70R18. 175/45R23, 175/55R19, 175/55R20, 175/55R22, 175/60R18, 185/45R22, 185/50R20, 185/55R19, 185/55R20, 185/60R19, 185/60R20, 195/50R20, 195 /55R20, 195/60R19, 205/50R21, 205/55R20, 215/50R21.

In the tire according to the embodiment of the third aspect of the present invention, the sectional width SW (mm) and the outer diameter OD (mm) of the tire are expressed by a relational expression,
OD (mm) ≥-0.0187 x SW (mm) ² +9.15 x SW (mm)-380
It has a narrow width and a large diameter.
By satisfying the above relational expression, the air resistance can be reduced and the rolling resistance can be reduced, whereby the fuel efficiency of the tire can be improved.
In the third aspect, the sectional width SW and the outer diameter OD of the tire satisfy the above relational expression, and the ratio SW/OD is preferably 0.26 or less, and is 0.25 or less. More preferably, it is more preferably 0.24 or less. This is because the fuel efficiency of the tire can be further improved.
The above relational expression and/or ratio is preferably satisfied when the internal pressure of the tire is 200 kPa or more, more preferably 220 kPa or more, and more preferably 280 kPa or more. More preferably, it is satisfied. This is because the rolling resistance can be reduced. On the other hand, it is preferable that the above relational expressions and/or ratios are satisfied when the internal pressure of the tire is 350 kPa or less. This is because the riding comfort can be improved.
Here, from the viewpoint of securing the ground contact area, the tire cross-section width SW is preferably 105 mm or more, more preferably 125 mm or more, and more preferably 135 mm or more in the range satisfying the above relational expression. More preferably, it is more preferably 145 mm or more. On the other hand, from the viewpoint of reducing the air resistance, the sectional width SW of the tire is preferably 230 mm or less, more preferably 215 mm or less, and more preferably 205 mm or less in the range satisfying the above relational expression. More preferably, it is particularly preferably 195 mm or less. From the viewpoint of reducing rolling resistance, the outer diameter OD of the tire is preferably 500 mm or more, more preferably 550 mm or more, and further preferably 580 mm or more in the range satisfying the above relational expression. preferable. On the other hand, from the viewpoint of reducing air resistance, the outer diameter OD of the tire is preferably 800 mm or less, more preferably 750 mm or less, and even more preferably 720 mm or less in the range satisfying the above relational expression. More preferable. From the viewpoint of reducing rolling resistance, the rim diameter is preferably 16 inches or more, and more preferably 17 inches or more when the sectional width SW and the outer diameter OD of the tire satisfy the above relational expressions. And more preferably 18 inches or more. On the other hand, from the viewpoint of reducing air resistance, the rim diameter is preferably 22 inches or less, and more preferably 21 inches or less when the tire sectional width SW and the outer diameter OD satisfy the above relational expressions. It is preferably 20 inches or less. Further, the flatness of the tire is more preferably 45 to 70, and further preferably 45 to 65 when the sectional width SW and the outer diameter OD of the tire satisfy the above ratios.
The specific tire size is not particularly limited, but as an example, 105/50R16, 115/50R17, 125/55R20, 125/60R18, 125/65R19, 135/45R21, 135/55R20, 135/60R17. , 135/60R18, 135/60R19, 135/65R19, 145/45R21, 145/55R20, 145/60R16, 145/60R17, 145/60R18, 145/60R19, 145/65R19, 155/45R18, 155/45R21, 155 /55R18, 155/55R19, 155/55R21, 155/60R17, 155/65R18, 155/70R17, 155/70R19, 165/45R22, 165/55R18, 165/55R19, 165/55R20, 165/55R21, 165/60R19. , 165/65R19, 165/70R18, 175/45R23, 175/55R18, 175/55R19, 175/55R20, 175/55R22, 175/60R18, 185/45R22, 185/50R20, 185/55R19, 185/55R20, 185 /60R19, 185/60R20, 195/50R20, 195/55R20, 195/60R19, 205/50R21, 205/55R20, 215/50R21.

FIG. 2 is a sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to an embodiment of the first to third aspects of the present invention. FIG. 2 shows a cross-section in the width direction of the tire when the tire is incorporated into a rim, a specified internal pressure is filled, and no load is applied. As shown in FIG. 2, the tire 1 is provided with a carcass 3 made of a ply of a radial arrangement cord, which extends in a toroidal manner between a pair of bead portions 2. Further, the tire 1 is provided with a belt 4 and a tread 5, which are two layers of

belt layers

4a and 4b in the illustrated example, in that order on the tire radial outside of the carcass 3.

In this example, a bead core 2a is embedded in each of the pair of bead portions 2. In the present invention, the cross-sectional shape and the material of the bead core 2a are not particularly limited, and the bead core 2a may have a configuration normally used in a pneumatic radial tire for passenger cars. In the present invention, the bead core 2a may be divided into a plurality of small bead cores. Alternatively, in the present invention, the bead core 2a may be omitted.

The tire 1 in the illustrated example has a bead filler 2b having a substantially triangular cross section on the tire radial outside of the bead core 2a. The cross-sectional shape of the bead filler 2b is not limited to this example, and the material is not particularly limited. Alternatively, it is possible to reduce the weight of the tire by using the configuration without the bead filler 2b.

In the present embodiment, the tire width direction cross-sectional area S1 of the bead filler 2b is preferably 1 to 4 times the tire width direction cross-sectional area S2 of the bead core 2a. By setting the cross-sectional area S1 to 1 times or more of the cross-sectional area S2, the rigidity of the bead portion 2 can be ensured, and by setting the cross-sectional area S1 to 4 times or less of the cross-sectional area S2, the tire is This is because the weight can be reduced and the fuel economy can be further improved. Further, in the present embodiment, at the tire maximum width position (the tire radial direction position where the width in the tire width direction is the maximum, and when it is the tire radial direction region, the tire radial direction center position of that region) The ratio Ts/Tb of the gauge Ts of the sidewall portion and the bead width (width of the bead portion 2 in the tire width direction) Tb at the tire radial center of the bead core 2a is preferably 15% or more and 40% or less. .. By setting the ratio Ts/Tb to 15% or more, the rigidity of the sidewall portion can be secured. On the other hand, by setting the ratio Ts/Tb to 40% or less, the tire can be made lighter and the fuel economy can be improved. This is because it can be further improved. Note that the gauge Ts is the sum of the thicknesses of all the members such as rubber, the reinforcing member, and the inner liner (however, even when the noise suppressor is arranged on the inner surface of the sidewall portion, the thickness of the noise suppressor is Not included). In the case where the bead core 2a is divided into a plurality of small bead cores by the carcass 3, the distance between the innermost end and the outermost end in the tire width direction of all the small bead cores is Tb. Further, in the present embodiment, it is preferable that the ratio Ts/Tc of the gauge Ts of the sidewall portion at the tire maximum width position and the diameter Tc of the carcass cord is 5 or more and 10 or less. By setting the ratio Ts/Tc to 5 or more, the rigidity of the sidewall portion can be secured, while setting the ratio Ts/Tc to 10 or less makes the tire lighter and further improves fuel economy. This is because it can be improved. In the present embodiment, the maximum tire width position is, for example, in the range of 50% to 90% in terms of tire cross-sectional height from the bead base line (imaginary line that passes through the bead base and is parallel to the tire width direction) to the tire radial outside. Can be provided.
Here, the "bead portion" refers to a portion in the tire radial region from the rim baseline to the tire radial outermost end of the bead filler when it has a bead filler, and when it does not have a bead filler, The portion in the tire radial direction region from the baseline to the tire radial outermost end of the bead core.

In the present embodiment, the tire 1 may have a structure having a rim guard. Further, in the present embodiment, the bead portion 2 may be further provided with an additional member such as a rubber layer or a cord layer for the purpose of reinforcement or the like. Such an additional member can be provided at various positions with respect to the carcass 3 and the bead filler 2b.

In the example shown in FIG. 2, the carcass 3 is composed of one carcass ply. On the other hand, in the present invention, the number of carcass plies is not particularly limited, and may be two or more. Further, in the example shown in FIG. 2, the carcass 3 includes a carcass body portion 3a that straddles between the pair of bead portions 2 in a toroidal shape, and a folded portion 3b that is folded from the carcass body portion 3a around the bead core 2a. Have On the other hand, in the present invention, the carcass folded-back portion 3b may be wound around the bead core 2a or may be sandwiched between a plurality of divided small bead cores. In the illustrated example, the end 3c of the carcass folded-back portion 3b is located outside the tire radial direction outer end of the bead filler 2b in the tire radial direction and inside the tire maximum width position in the tire radial direction. As a result, it is possible to reduce the weight of the tire while ensuring the rigidity of the sidewall portion. On the other hand, in the present invention, the end 3c of the carcass folded-back portion 3b may be located on the tire radial direction inner side from the tire radial direction outer end of the bead filler 2b, or on the tire radial direction outer side from the tire maximum width position. It may be located. Alternatively, the end 3c of the carcass folded-back portion 3b is positioned inside the tire width direction from the end of the belt 4 (for example, the end of the belt layer 4b) so as to be located between the carcass body 2a and the belt 4 in the tire radial direction. It may also be an envelope structure. Further, when the carcass 3 is composed of a plurality of carcass plies, the positions (for example, tire radial direction positions) of the ends 3c of the carcass folded-back portions 3b may be the same or different between the carcass plies. . The number of cords to be driven into the carcass 3 is not particularly limited, but may be, for example, 20 to 60 cords/50 mm. Further, various structures can be adopted for the carcass line. For example, the carcass maximum width position can be brought closer to the bead portion 2 side or the tread 5 side in the tire radial direction. For example, the carcass maximum width position can be provided outside the bead base line in the tire radial direction in the range of 50% to 90% in terms of the tire cross-sectional height. The “radial arrangement” is 85° or more with respect to the tire circumferential direction, and preferably 90° with respect to the tire circumferential direction.

The tire according to the present embodiment preferably has one or more inclined belt layers formed of rubberized layers of cords that extend obliquely with respect to the tire circumferential direction, and is a compromise between weight reduction and suppression of ground plane shape distortion. It is most preferable to have two layers. The belt layer may be a single layer from the viewpoint of weight reduction, or may be three or more layers from the viewpoint of suppressing distortion of the ground contact surface shape. In the example shown in FIG. 2, of the two

belt layers

4a and 4b, the width in the tire width direction of the belt layer 4b on the tire radial direction outer side is smaller than the width of the belt layer 4a on the tire radial direction inner side in the tire width direction. .. On the other hand, the width in the tire width direction of the belt layer 4b on the outer side in the tire radial direction can be made larger than or the same as the width of the belt layer 4a on the inner side in the tire radial direction in the tire width direction. The width of the belt layer having the largest width in the tire width direction (the belt layer 4a in the illustrated example) in the tire width direction is preferably 90 to 115% of the ground contact width, and 100 to 105% of the ground contact width. Particularly preferred. The "ground contact width" means the distance in the tire width direction between the ground contact ends E on the ground contact surface.
In the present embodiment, it is most preferable to use a metal cord, particularly a steel cord, as the belt cord of the belt layers 4a and 4b, but an organic fiber cord can also be used. The steel cord is mainly composed of steel and may contain various trace contents such as carbon, manganese, silicon, phosphorus, sulfur, copper and chromium. In the present embodiment, the belt cords of the belt layers 4a and 4b may be monofilament cords, cords in which a plurality of filaments are aligned, or cords in which a plurality of filaments are twisted. Various twist structures can be adopted, and the cross-sectional structure, twist pitch, twist direction, and distance between adjacent filaments can be various. Furthermore, a cord formed by twisting filaments of different materials can be used, and the cross-sectional structure is not particularly limited, and various twist structures such as single twist, layer twist, and double twist can be adopted.
In the present embodiment, the inclination angle of the belt cords of the belt layers 4a and 4b is preferably 10° or more with respect to the tire circumferential direction. In the present embodiment, the inclination angle of the belt cords of the belt layers 4a and 4b is a high angle, specifically 20° or more, preferably 35° or more, and particularly 55° to the tire circumferential direction with respect to the tire circumferential direction. It is preferably in the range of 85°. This is because by setting the inclination angle to 20° or more (preferably 35° or more), the rigidity in the tire width direction can be increased, and particularly the steering stability performance during cornering can be improved. Also, it is possible to reduce the shear deformation of the interlayer rubber and reduce the rolling resistance.

The tire according to the present embodiment has a configuration in which one or more circumferential belt layers including cords extending substantially along the tire circumferential direction are not provided outside the belt 4 in the tire radial direction. On the other hand, in the present invention, a configuration in which a circumferential belt composed of one or more circumferential belt layers can be provided outside the belt 4 in the tire radial direction. In particular, when the belt cords of the belt layers 4a and 4b forming the belt 4 have inclination angles θ1 and θ2 of 35° or more, it is preferable to provide a circumferential belt, and the circumferential belt is a unit of the center region C. The tire circumferential rigidity per width is preferably higher than the tire circumferential rigidity per unit width of the shoulder region S.
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a non-loaded state, a tire width direction area of the tire width direction center 50% between the ground contact ends E is defined as a center area C, The tire width direction regions of 25% on both sides in the tire width direction from the center region are defined as shoulder regions S.
For example, by setting the number of circumferential belt layers in the center region C to be greater than that in the shoulder region S, the tire circumferential rigidity per unit width of the center region C can be made smaller than the tire circumferential rigidity per unit width of the shoulder region S. Can be higher. Here, most of the tires in which the belt cords of the belt layers 4a and 4b incline at 35° or more with respect to the tire circumferential direction have a primary, secondary, and tertiary order in the cross-sectional direction in a high frequency range of 400 Hz to 2 kHz. In the vibration mode, since the tread tread has a shape that vibrates uniformly and greatly, a large radiated sound is generated. Therefore, if the tire circumferential rigidity of the center region C of the tread 5 is locally increased, the center region C of the tread 5 becomes difficult to spread in the tire circumferential direction, and the tread tread's spread in the tire circumferential direction is suppressed. , Radiated sound can be reduced.
In the present embodiment, the inclination angle θ1 of the belt cord of the belt layer having the largest width in the tire width direction (belt layer 4a in the illustrated example) with respect to the tire circumferential direction, and the belt layer having the smallest width in the tire width direction (in the illustrated example, It is also preferable that the inclination angle θ2 of the belt cord of the belt layer 4b) with respect to the tire circumferential direction satisfies 35°≦θ1≦85°, 10°≦θ2≦30°, and θ1>θ2. Most of tires provided with a belt layer having a belt cord inclined at 35° or more with respect to the tire circumferential direction are subjected to a vibration mode such as a primary, secondary and tertiary vibration in a cross-sectional direction in a high frequency range of 400 Hz to 2 kHz. As a result, the tread surface is uniformly vibrated and a large radiated sound is produced. Therefore, if the tire circumferential rigidity of the center region C of the tread 5 is locally increased, the center region C of the tread 5 becomes difficult to spread in the tire circumferential direction, and the tread tread's spread in the tire circumferential direction is suppressed. , Radiated sound can be reduced.
Here, in the present embodiment, when the circumferential belt is provided, the circumferential belt layer preferably has high rigidity, and more specifically, the circumferential belt layer is made of a rubberized layer of a cord extending in the tire circumferential direction. When the rate is Y (GPa), the number of driving is n (pieces/50 mm), the circumferential belt layer is m layers, and the cord diameter is d (mm), X=Y×n×m×d It is preferable that 1500≧X≧225. In a pneumatic radial tire for passenger cars of narrow width and large diameter, local deformation occurs in the tire circumferential direction with respect to the input when turning from the road surface, and the ground contact surface has a substantially triangular shape, that is, the position in the tire width direction. Therefore, the contact length in the circumferential direction tends to change greatly. On the other hand, by using a highly rigid circumferential belt layer, the ring rigidity of the tire is improved and deformation in the tire circumferential direction is suppressed. Deformation is also suppressed, and the ground contact shape is less likely to change. Further, since the ring rigidity is improved, the eccentric deformation is promoted, and the rolling resistance is also improved at the same time. Furthermore, when the high-rigidity circumferential belt layer is used as described above, the inclination angle of the belt cords of the belt layers 4a and 4b with respect to the tire circumferential direction may be a high angle, specifically, 35° or more. preferable. When a high-rigidity circumferential belt layer is used, the rigidity in the tire circumferential direction becomes high, which may reduce the ground contact length depending on the tire. Therefore, by using a belt layer with a high angle, it is possible to reduce the out-of-plane bending rigidity in the tire circumferential direction, increase the elongation of the rubber in the tire circumferential direction when the tread deforms, and suppress the decrease in the ground contact length. .. Further, in the present embodiment, a wavy cord may be used for the circumferential belt layer in order to increase the breaking strength. Similarly, a high elongation cord (for example, elongation at break of 4.5 to 5.5%) may be used to increase the breaking strength. Further, in the present embodiment, various materials can be used for the circumferential belt layer, and typical examples are rayon, nylon, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), aramid, glass. Fiber, carbon fiber, steel, etc. can be used. From the viewpoint of weight reduction, organic fiber cords are particularly preferable. Here, in the present embodiment, when the circumferential belt is provided, the cord of the circumferential belt layer is a monofilament cord, a cord in which a plurality of filaments are aligned, a cord in which a plurality of filaments are twisted, and a different material. It is also possible to use a hybrid cord formed by twisting filaments. Further, in the present embodiment, the number of circumferential belt layers to be driven can be set in a range of 20 to 60 lines/50 mm, but the number is not limited to this range. Further, in the present embodiment, distribution of rigidity, material, number of layers, driving density, and the like can be provided in the tire width direction, and the number of layers of the circumferential belt layer can be increased only in the shoulder portion S, for example. On the other hand, the number of circumferential belt layers can be increased only in the center region C. Further, in the present embodiment, the circumferential belt layer may have a width in the tire width direction larger or smaller than that of the belt layers 4a and 4b. For example, the width in the tire width direction of the circumferential belt layer is 90% to 110% of the width in the tire width direction of the belt layer (belt layer 4a in the illustrated example) having the largest width in the tire width direction among the belt layers 4a and 4b. It can be %. Here, it is particularly advantageous from the viewpoint of manufacturing that the circumferential belt layer is configured as a spiral layer.

In the illustrated example, the tread rubber forming the tread 5 is composed of one layer. On the other hand, in the present embodiment, the tread rubber forming the tread 5 may be formed by laminating a plurality of different rubber layers in the tire radial direction. As the plurality of rubber layers, those having different tangent loss, modulus, hardness, glass transition temperature, material and the like can be used. Further, the ratio of the thickness of the plurality of rubber layers in the tire radial direction may be changed in the tire width direction, and only the circumferential main groove bottom or the like may be a rubber layer different from the periphery thereof. The tread rubber that constitutes the tread 5 may be formed of a plurality of rubber layers that are different in the tire width direction. As the plurality of rubber layers, those having different tangent loss, modulus, hardness, glass transition temperature, material, etc. can be used. Further, the ratio of the width in the tire width direction of the plurality of rubber layers may be changed in the tire radial direction, and only in the vicinity of the circumferential main groove, only in the vicinity of the ground contact end, only in the shoulder land portion, only in the center land portion, etc. Only a limited part of the area may be a rubber layer different from the surrounding area.
Further, in the present embodiment, in the tire width direction cross section, a straight line parallel to the tire width direction passing through the point P on the tread surface CL of the tire equatorial plane CL is defined as a straight line parallel to the tire width direction passing through the ground contact end E. As m2, when the distance between the straight line m1 and the straight line m2 in the tire radial direction is set to be the height L _CR and the ground contact width of the tire is W, the ratio L _CR /W is preferably 0.045 or less. By setting the ratio L _CR /W in the above range, the crown portion of the tire is flattened (flattened), the ground contact area is increased, and the input (pressure) from the road surface is relaxed, so that the tire radial direction It is possible to reduce the deflection rate and improve the durability and wear resistance of the tire.

In the illustrated example, the tire 1 has three circumferential main grooves 6 extending in the tire circumferential direction. Specifically, one circumferential main groove 6 is provided on the tire equatorial plane CL, and one circumferential main groove 6 is provided in each shoulder region S on both sides in the tire width direction. The groove width (opening width) of the circumferential main groove 6 is not particularly limited, but may be, for example, 2 mm to 5 mm.
In the present embodiment, it is preferable to reduce the amount of grooves occupying the tread 5 from the viewpoint of achieving both wet performance and other performance. Specifically, the groove volume ratio (groove volume V2/tread rubber volume V1) is preferably 30% or less, and the negative ratio (ratio of the groove area to the tread tread area) is 30% or less. Preferably.
As will be described later, in a pneumatic radial tire for a passenger car having a narrow width and a large diameter, the ground contact pressure in the center region C is higher than that in the shoulder region S, so that heat generation in the center region C tends to be relatively large. Therefore, as in the present embodiment, by providing one circumferential main groove 6 in the center region C (on the tire equatorial plane CL in the illustrated example), heat can be efficiently dissipated. Further, as will be described later, in the present embodiment, since the noise suppressor 9 (sponge material) is provided on the inner surface 7 of the tire in the shoulder region S at each half in the tire width direction with the tire equatorial plane CL as the boundary, By having one or more (one in this example) circumferential main groove 6 in each shoulder region S, heat can be efficiently radiated.
On the other hand, in a tire in which the rigidity of the center region C in the tire circumferential direction is increased by a belt structure or the like, the tread 5 has a land portion continuous in the tire circumferential direction in a region including at least the tire equatorial plane CL of the tread tread surface. However, it is preferable from the viewpoint of ensuring the contact length and improving the cornering performance.
In the present invention, the number and arrangement of the circumferential main grooves 6 are not particularly limited to the above example. Further, a widthwise groove extending in the tire widthwise direction, a sipe closed at the time of contact with the ground, and the like can be appropriately provided.
Further, from the viewpoint of satisfying both noise performance and wet performance, the cross-sectional area of each circumferential direction main grooves it is preferably set to 24 mm ² or more 96 mm ² or less, the number of the time circumferential main groove, two or more is preferably set to five or less, therefore, the sum of the cross-sectional area of the circumferential main groove in the entire tread surface, it is preferable that the 48 mm ² or more 480 mm ² or less.

The tire 1 of the present embodiment has an inner liner 8 on the inner surface 7 of the tire (hereinafter, also simply referred to as the tire inner surface 7). The inner liner 8 preferably has a thickness of about 1.5 mm to 2.8 mm. This is because the vehicle interior noise of 80 to 100 Hz can be effectively reduced. The air permeability coefficient of the rubber composition constituting the inner liner 8 is 1.0×10 ⁻¹⁴ cc·cm/(cm ² ·s·cmHg) or more and 6.5×10 ⁻¹⁰ cc·cm/(cm ² ·S·cmHg) or less is preferable. Further, it is preferable to have one or more particles containing fluorine having a maximum diameter of 1.0 μm or more per 100 μm ² area of the tire inner surface, and a plurality of bladder ridges extending in the tire width direction are formed on the circumference of the tire inner surface. It is preferable that five or more bladder ridges are formed per inch in the tire circumferential direction at any position on the inner surface of the tire in the tire width direction.
In the present embodiment, the inner liner 8 can be formed of a rubber layer mainly containing butyl rubber or a film layer mainly containing resin. In the present embodiment, a sealant member for preventing air leakage at the time of puncture can be provided in a portion of the tire inner surface 7 where the noise suppressor 9 is not arranged.

As shown in FIG. 2, the tire 1 of the present embodiment is provided with one or more (one in the illustrated example) noise suppressors 9 on the tire inner surface 7 (in this example, the inner surface of the inner liner 8). .. In this example, the noise suppressor 9 is a sponge material.
In the present embodiment, the noise suppressor 9 is provided at least on the tire inner surface 7 in the shoulder region S. In the illustrated example, the noise suppressor 9 extends from the tire inner surface 7 in the shoulder region S on one half of the tire width direction bounded by the tire equatorial plane CL to the tire inner surface 7 in the shoulder region S on the other half of the tire width direction. Both ends of the noise damper 9 in the direction along the tire inner surface 7 are located in the shoulder regions S of both half portions in the tire width direction (in the illustrated example, of the shoulder region S). At the tire width direction outer end position (that is, at the ground contact end E). In the present invention, the noise damper 9 may be provided at least on the tire inner surface 7 in the shoulder region S, and the end of the noise damper 9 is located inside the ground contact end E in the tire width direction. May be.
In the illustrated example, the noise damper 9 is bonded to all or part of the tire inner surface 7 via an adhesive layer (not shown) containing an adhesive. Any known adhesive layer can be used. Alternatively, they may be adhered by fusion or the like. In order to secure the adhesive force, it is preferable to adhere the entire area of the area in contact with the tire inner surface 7 as in this example. When the inner liner 8 is not provided on the tire inner surface 7, the noise suppressor 9 can be provided by directly adhering to the tire inner surface 7.
Further, it is preferable that the noise suppressor 9 is composed of one noise suppressor 9 in the continuous extending region, but it may be constituted by adhering two or more noise suppressors 9 with an adhesive layer or the like. it can.

In the present embodiment, the noise suppressor 9 continuously extends in the tire circumferential direction. In the illustrated example, the noise damper 9 is not divided in the tire circumferential direction, but two or more noise dampers 9 divided in the tire circumferential direction are bonded in the tire circumferential direction with an adhesive layer or the like. You can also do it. Alternatively, the noise suppressor 9 may extend discontinuously in the tire circumferential direction. In this case, from the viewpoint of improving the sound damping property, it is preferable that the total extension be 80% or more of the entire area in the tire circumferential direction. Further, when the noise suppressor 9 extends discontinuously in the tire circumferential direction, from the viewpoint of improving the uniformity in the circumferential direction of the tire, the noise suppressor 9 having the same circumferential length is used at equal intervals. It is preferable to arrange at a directional pitch.

In the present embodiment, the noise suppressor 9 has a substantially rectangular cross-sectional shape (however, the side bonded to the tire inner surface 7 is along the tire inner surface shape). The cross-sectional shape of the noise suppressor 9 may be any shape such as another polygonal shape such as a triangular shape, a trapezoidal shape, a circular shape, an elliptical shape, or the like. From the viewpoint of ensuring a bonding area between the noise damper 9 and the tire inner surface 7 and increasing the volume of the noise damper 9 as compared with the bonding area, the cross-sectional shape of the noise damper 9 is substantially rectangular. It is preferable that
In this embodiment, the noise suppressor 9 has the same cross-sectional shape and size in any cross section in the tire width direction, but may change in the tire circumferential direction.
The volume of the noise damper 9 is preferably 0.1% to 80% of the total volume of the tire inner cavity. By setting the volume of the noise suppressor 9 to 0.1% or more with respect to the total volume of the tire inner cavity, the effect of reducing cavity resonance noise can be effectively obtained, while the total volume of the tire inner cavity is reduced. On the other hand, by setting the volume of the noise damper 9 to 80% or less, the weight increase by the noise damper 9 can be suppressed. Further, it is possible to prevent heat from being accumulated in the noise suppressor 9. For the same reason, the volume of the noise damper 9 is preferably 5 to 70% of the total volume of the tire inner cavity, and more preferably 15 to 50%.
For the sake of convenience, dimensions are shown in the figure showing the state where the tire is built into the rim and the specified internal pressure is filled, but the volume of the noise suppressor and the width, thickness, flatness, cross-sectional area, peripheral length, etc., which will be described later, are shown. Indicates that the tire is removed from the rim at room temperature and pressure.

Here, as shown in FIG. 2, the peripheral length along the tire inner surface 7 of the noise suppressor 9 was set to L1 (mm), and measurement was performed in a direction orthogonal to the direction along the tire inner surface 7 of the noise suppressor 9. When the maximum thickness is T1 (mm), the ratio T1/L1 is 0.2 or more and 0.8 or less.

The material forming the noise suppressor 9 can be controlled so as to reduce the cavity resonance energy by relaxation, absorption of the cavity resonance energy, conversion to another energy (for example, thermal energy), or the like. Of course, it is not limited to the sponge material described above, and for example, a non-woven fabric made of organic fibers or inorganic fibers may be used.

When the noise suppressor 9 is a sponge material as in the present embodiment, the sponge material can be a sponge-like porous structure, and has, for example, open cells formed by foaming rubber or synthetic resin, Including so-called sponge. Further, the sponge material includes, in addition to the above-mentioned sponge, a web-shaped material in which animal fibers, plant fibers, synthetic fibers or the like are entwined and integrally connected. Note that the above-mentioned “porous structure” is not limited to a structure having open cells, but includes a structure having closed cells. The sponge material as described above converts the vibration energy of air in which the voids formed on the surface and inside vibrate into heat energy. Thereby, cavity resonance in the tire inner cavity is suppressed, and as a result, road noise can be reduced.
Examples of the material of the sponge material include synthetic polyurethane resin sponges such as ether polyurethane sponge, ester polyurethane sponge, polyethylene sponge, chloroprene rubber sponge (CR sponge), ethylene propylene rubber sponge (EPDM sponge), nitrile rubber sponge (NBR sponge). ) Such as rubber sponge. From the viewpoints of noise control, lightness, controllability of foaming, durability, etc., it is preferable to use a polyurethane-based or polyethylene-based sponge including an ether-based polyurethane sponge.

The total cross-sectional area of the noise suppressor 9 in the tire width direction cross section is preferably 20 to 30000 (mm ² ). When the total cross-sectional area is 20 (mm ² ) or more, the sound damping property can be further improved. On the other hand, when the total cross-sectional area is 30000 (mm ² ) or less, the noise suppressor 9 is heated. This is because it is possible to suppress the muddyness and further improve the tire durability. For the same reason, the total cross-sectional area is more preferably 100 (mm ² ) to 20000 (mm ² ), more preferably 1000 (mm ² ) to 18000 (mm ² ), and 3000 (mm ² ) to 15000 (mm ² ) is more preferable.
When the noise suppressor 9 is a sponge material as in the present embodiment, the hardness of the sponge material is not particularly limited, but is preferably in the range of 5N to 450N. By setting the hardness to 5 N or more, the sound damping property can be improved, and by setting the hardness to 450 N or less, the adhesive force of the sound damping body can be increased. Similarly, the hardness of the noise damper is more preferably in the range of 8 to 300N. Here, the "hardness" is a value measured according to the A method of 6.3 in the measuring method of 6th item of JIS K6400.
The specific gravity of the sponge material is preferably 0.001 to 0.090. By setting the specific gravity of the sponge material to 0.001 or more, the sound damping property can be improved, and on the other hand, by setting the specific gravity of the sponge material to 0.090 or less, the increase in weight due to the sponge material is suppressed. Because you can. Similarly, the specific gravity of the sponge material is more preferably 0.003 to 0.080. Here, the “specific gravity” is a value obtained by converting the apparent density into a specific gravity in accordance with the measuring method of the fifth item of JIS K6400.
The tensile strength of the sponge material is preferably 20 kPa to 500 kPa. By setting the tensile strength to 20 kPa or more, the adhesive force can be improved, and on the other hand, by setting the tensile strength to 500 kPa or less, the productivity of the sponge material can be improved. Similarly, the tensile strength of the sponge material is more preferably 40 to 400 kPa. Here, the “tensile strength” is a value measured by a No. 1 dumbbell-shaped test piece in accordance with the measuring method of Item 10 of JIS K6400.
The elongation at break of the sponge material is preferably 110% or more and 800% or less. By setting the elongation at break to 110% or more, it is possible to suppress the occurrence of cracks in the sponge material, while setting the elongation at break to 800% or less increases the productivity of the sponge material. This is because it can be improved. Similarly, the elongation at break of the sponge material is more preferably 130% or more and 750% or less. Here, the "elongation at break" is a value measured with a No. 1 dumbbell-shaped test piece in accordance with the measuring method of Item 10 of JIS K6400.
The tear strength of the sponge material is preferably 1 to 130 N/cm. By setting the tear strength to 1 N/cm or more, it is possible to suppress the generation of cracks in the sponge material, while setting the tear strength to 130 N/cm or less improves the manufacturability of the sponge material. This is because it can be improved. Similarly, the tear strength of the sponge material is more preferably 3 to 115 N/cm. Here, the “tear strength” is a value measured with a No. 1 type test piece in accordance with the measuring method of Item 11 of JIS K6400.
The foaming rate of the sponge material is preferably 1% or more and 40% or less. This is because by setting the foaming rate to 1% or more, the sound damping property can be improved, and on the other hand, by setting the foaming rate to 40% or less, the productivity of the sponge material can be improved. Similarly, the foaming rate of the sponge material is more preferably 2 to 25%. Here, the "foaming rate" means a value obtained by subtracting 1 from the ratio A/B of the specific gravity A of the solid phase portion of the sponge material to the specific gravity B of the sponge material and multiplying the value by 100.
The mass of the sponge material is preferably 5 to 800 g. This is because if the mass is 5 g or more, the sound damping property can be reduced, and if the mass is 800 g or less, the weight increase due to the sponge material can be suppressed. Similarly, the mass of the sponge material is preferably 20 to 600 g.

Hereinafter, the operational effects of the pneumatic radial tire for a passenger vehicle according to the present embodiment according to the first to third aspects of the present invention will be described.

In the pneumatic radial tire for passenger cars of the present embodiment, the tire cross-section width SW and the tire outer diameter OD satisfy the above-mentioned predetermined relationship (that is, in the first aspect, the tire cross-section width SW is The cross-sectional width SW of the tire is less than 165 (mm), and the ratio SW/OD of the tire cross-sectional width SW to the outer diameter OD is 0.26 or less. ) It is above, and the cross-sectional width SW (mm) and outer diameter OD (mm) of the tire satisfy the relational expression, OD (mm)≧2.135×SW (mm)+282.3. In the aspect of 3, the relational expression, OD (mm)≧−0.0187×SW (mm) ² +9.15×SW (mm)−380, is satisfied). Thereby, as described above, the fuel efficiency can be improved.
By the way, as schematically shown in FIGS. 3 and 4, in a pneumatic radial tire for a passenger vehicle of a normal tire size, the ground contact pressure tends to be higher in the shoulder region S than in the center region C. Therefore, in a pneumatic radial tire for a passenger car having a narrow width and a large diameter, in which the sectional width SW and the outer diameter OD of the tire satisfy the above-mentioned predetermined relationship, the ground contact pressure is equal to or higher than the shoulder area S in the center area C. Tends to be higher. From this, it is clear that the heat generation in the shoulder region S is relatively small in the narrow width and large diameter pneumatic radial tire for passenger cars in which the tire cross-sectional width SW and the outer diameter OD satisfy the above-mentioned predetermined relationship. did.

Therefore, in the pneumatic radial tire for a passenger vehicle of the present embodiment, one or more noise dampers 9 are provided on the tire inner surface 7, and the noise damper 9 is provided at least on the tire inner surface 7 in the shoulder region S. ..
As a result, the extending region of the noise suppressor 9 can be secured so as to include the shoulder region S, so that the noise suppressing property can be enhanced, and the heat generation in the shoulder region S is relatively low. From the above, it is possible to prevent the noise suppressor 9 from peeling from the tire inner surface 7 due to melting of the adhesive layer or the like, and to prevent failure of other members due to heat buildup in the noise suppressor 9 and a high temperature inside the tire. It is also possible to improve the durability of the tire.
Here, the higher the internal pressure of the tire, the higher the ground pressure becomes in the center region C in comparison with the shoulder region S. Therefore, the predetermined relationship between the sectional width SW of the tire and the tire outer diameter OD is that the internal pressure is It is preferably satisfied when it is 200 kPa or more, more preferably satisfied when it is 220 kPa or more, and further preferably satisfied when it is 280 kPa or more. This is because the above effects can be obtained more effectively, and the rolling resistance can be further reduced by setting the internal pressure to a high value. On the other hand, the predetermined relationship between the sectional width SW of the tire and the tire outer diameter OD is preferably satisfied when the internal pressure is 350 kPa or less. This is because the riding comfort can be improved.

Further, in the present embodiment, the noise suppressor 9 extends from the tire inner surface 7 in one half of the shoulder area S in the tire width direction bounded by the tire equatorial plane CL to the other half of the shoulder area S in the tire width direction. Both ends of the noise suppressor 9 extending in the direction along the tire inner surface 7 are continuously located in the tire inner surface 7, and both ends of the noise suppressor 9 are located in the shoulder regions S of both half portions in the tire width direction (in the illustrated example, the shoulder area). Since the region S is located at the outer end position in the tire width direction (that is, at the ground contact end E), it is possible to secure the volume of the noise suppressor 9 and further improve the noise suppressing property. Further, as compared with the case where the noise suppressor 9 is provided outside the shoulder region S in the tire width direction, it is possible to suppress heat from being accumulated in the noise suppressor 9 and improve tire durability. The weight increase can be further suppressed.
Further, in the present embodiment, a sponge material is used as the noise suppressor 9, and since the sponge material can exhibit high sound damping property despite its small specific gravity, it is possible to prevent an excessive weight increase. The noise control property can be further improved.

Further, in the present embodiment, the ratio T1/L1 is set to 0.2 or more and 0.8 or less. If the ratio T1/L1 is less than 0.2, the thickness of the noise damper 9 is small and the noise damping property is deteriorated. On the other hand, if the ratio T1/L1 is more than 0.8, the noise damper 9 is reduced. This is because heat is likely to accumulate and tire durability is reduced. For the same reason, the ratio T1/L1 is preferably 0.3 or more and 0.6 or less.
As described above, according to the pneumatic radial tire for a passenger vehicle of the present embodiment, it is possible to achieve both sound damping and tire durability.

FIG. 5 is a cross-sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to another embodiment of the first to third aspects of the present invention. FIG. 5 shows a cross-section in the width direction of the tire when the tire is incorporated into a rim, a specified internal pressure is filled, and no load is applied.
The tire of the other embodiment shown in FIG. 5 is different from the tire of the previous embodiment shown in FIG. 2 only in the arrangement mode and size of the noise suppressor 9. Therefore, the configuration will be described below and other tires will be described. The description of the common configuration is omitted.
That is, in the tire of the embodiment shown in FIG. 5, the noise suppressor 9 is formed from the tire inner surface 7 in the sidewall portion of one half portion in the tire width direction bounded by the tire equatorial plane CL to the other half portion in the tire width direction. Of the noise suppressor 9 extending in a direction along the tire inner surface 7 at both sidewall portions of the sidewall portion of the tire width direction (in the illustrated example, the maximum tire width). It is located on the tire inner surface 7 at the tire radial direction inner side of the position and at the tire radial direction outer side of the tire radial direction outer end of the bead filler 2b).
In the embodiment shown in FIG. 5, the thickness of the noise damper 9 measured in the direction orthogonal to the tire inner surface 7 is substantially constant, and has the maximum thickness T1 (mm) on the tire equatorial plane CL.
Also with the tire of the embodiment shown in FIG. 5, since the extending region of the noise suppressor 9 can be ensured so as to include the shoulder region S, the noise suppressing property can be improved, and the shoulder region S can be improved. Since the heat generation in the tire is relatively low, the noise suppressor 9 is separated from the tire inner surface 7 due to melting of the adhesive layer or the like, and heat is accumulated in the noise suppressor 9 to increase the temperature inside the tire. It is possible to suppress the breakdown of members and improve the durability of the tire.
Further, similar to the embodiment shown in FIG. 2, the ratio T1/L1 is set to 0.2 or more and 0.8 or less. The ratio T1/L1 is preferably 0.3 or more and 0.6 or less.
For example, the thickness T1 of the noise suppressor 9 can be set to 5 to 40 mm in the range of the above ratio T1/L1.
Particularly, in the tire of the embodiment shown in FIG. 5, the noise suppressor 9 is provided over the center region C, the shoulder region S, and the sidewall portion (in the illustrated example, to the tire radial direction inner side from the tire maximum width position). Therefore, as compared with the embodiment shown in FIG. 2, it is possible to secure a large volume of the noise damper 9, and it is possible to further improve the noise damping property without significantly impairing the tire durability.
In the embodiment shown in FIG. 5, the innermost end of the noise suppressor 9 in the tire radial direction is located outside of the outermost end of the bead filler 2b in the tire radial direction. According to this, heat transfer from the bead filler 2b, which is a member that generates a large amount of heat, to the noise suppressor 9 can be suppressed, and tire durability can be improved.
On the other hand, the noise suppressor 9 may be provided up to the tire inner surface 7 of the bead portion 2. For example, the innermost end in the tire radial direction of the noise suppressor 9 is closer to the tire outer diameter end than the outermost end in the tire radial direction of the bead filler 2b. It may be located inside the direction. In this case, it is possible to secure a larger volume of the sound damping body 9 and improve the sound damping property.

FIG. 6 is a sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to another embodiment of the first to third aspects of the present invention. FIG. 6 shows a cross-section in the width direction of the tire when the tire is incorporated into a rim, the internal pressure is filled with the tire, and no load is applied.
The tire of another embodiment shown in FIG. 6 is different from the tire of the previous embodiment shown in FIGS. 2 and 5 only in the arrangement mode and size of the noise damper 9, and therefore the configuration will be described below. Description of other common configurations will be omitted.
In the tire of the embodiment shown in FIG. 6, the noise suppressor 9 continuously extends from the tire inner surface 7 in the shoulder region S to the tire inner surface 7 in the sidewall portion in each half portion in the tire width direction, One end of each half of the noise width direction in the tire width direction along the tire inner surface 7 is located on the tire inner surface 7 in the shoulder region S (the tire width direction inner end of the shoulder region S in the illustrated example), and The other end is located on the tire inner surface 7 in the sidewall portion (in the illustrated example, the tire radial direction inner side from the tire maximum width position and the tire radial direction outer end of the bead filler 2b).
Each noise suppressor 9 has a peripheral length L2 (mm) (by definition, L2 (mm)=L1 (mm)/2), and a maximum thickness T2 (=T1) (mm) at the tire width direction inner end. )have.
Also with the tire of the embodiment shown in FIG. 6, since the extending region of the noise suppressor 9 can be ensured so as to include the shoulder region S, the noise suppressing property can be enhanced, and the shoulder region S can be improved. Since the heat generation in the tire is relatively low, the noise suppressor 9 is separated from the tire inner surface 7 due to melting of the adhesive layer or the like, and heat is accumulated in the noise suppressor 9 to increase the temperature inside the tire. It is possible to suppress the breakdown of members and improve the durability of the tire.
Further, similar to the embodiment shown in FIGS. 2 and 5, the ratio T1/L1 is set to 0.2 or more and 0.8 or less. The ratio T1/L1 is preferably 0.3 or more and 0.6 or less.
For example, the thickness T1 of the noise suppressor 9 can be set to 5 to 40 mm in the range of the above ratio T1/L1.
Particularly, in the tire of the embodiment shown in FIG. 6, as compared with the embodiment shown in FIGS. 2 and 5, since the tire inner surface 7 in the center portion C that generates relatively large heat is not provided with the noise suppressor 9, In the center region C, the adhesive layer is melted to prevent the noise suppressor 9 from peeling from the tire inner surface 7, and heat from being transferred to the noise suppressor 9 to prevent other tire members from breaking down, thereby improving tire durability. It can be improved.
In the embodiment shown in FIG. 6, the innermost end of the noise suppressor 9 in the tire radial direction is located outside of the outermost end of the bead filler 2b in the tire radial direction. According to this, heat transfer from the bead filler 2b, which is a member that generates a large amount of heat, to the noise suppressor 9 can be suppressed, and tire durability can be improved.
On the other hand, the noise suppressor 9 may be provided up to the tire inner surface 7 of the bead portion 2. For example, the innermost end in the tire radial direction of the noise suppressor 9 is closer to the tire outer diameter end than the outermost end in the tire radial direction of the bead filler 2b. It may be located inside the direction. In this case, it is possible to secure a larger volume of the sound damping body 9 and improve the sound damping property.

FIG. 7 is a sectional view in the tire width direction showing a pneumatic radial tire for passenger cars according to still another embodiment of the first to third aspects of the present invention. FIG. 7 shows a cross-section in the width direction of the tire when the tire is incorporated in a rim, a specified internal pressure is filled, and no load is applied.
The tire of yet another embodiment shown in FIG. 7 is different from the tires of the previous embodiments shown in FIGS. 2, 5, and 6 only in the arrangement mode and size of the noise suppressor 9. The description will be given below, and the description of other common configurations will be omitted.
That is, in the tire of the embodiment shown in FIG. 7, the noise damper 9 extends intermittently in each half of the tire width direction from the tire inner surface 7 in the shoulder region S to the tire inner surface 7 in the sidewall portion. However, the noise suppressor 9 is not provided on the tire inner surface 7 in the center region C and the tire inner surface 7 in the buttress portion in each half portion in the tire width direction.
As shown in FIG. 7, in the present embodiment, in the noise suppressor 9 provided on the tire inner surface 7 in the shoulder region S, the width W3 of the noise suppressor 9 in the tire width direction is smaller than the thickness T3 of the noise suppressor 9. Large, flat shape. The noise suppressor 9 provided on the tire inner surface 7 in the shoulder region S has a substantially quadrangular cross-section (however, the side bonded to the tire inner surface 7 is along the tire inner surface shape). In the present invention, the cross-sectional shape of the noise suppressor 9 may be any shape such as another polygonal shape such as a triangular shape, a trapezoidal shape, a circular shape, an elliptical shape, or the like. From the viewpoint of ensuring a bonding area between the noise damper 9 and the tire inner surface 7 and increasing the volume of the noise damper 9 as compared with the bonding area, the cross-sectional shape of the noise damper 9 is substantially rectangular. It is preferable that
In the illustrated example, the noise suppressor 9 is provided on the tire inner surface 7 in the entire shoulder region S.
In the illustrated example, the thickness of the noise damper 9 in the shoulder region S gradually increases toward the inside in the tire width direction. In the illustrated example, the tire has a maximum thickness T3 (=T1) (mm) on the equatorial plane CL. The noise suppressor 9 provided on the tire inner surface 7 in the shoulder region S has a peripheral length L3 (mm).
Further, in the illustrated example, the noise suppressor 9 provided on the tire inner surface 7 in the sidewall portion is provided in substantially the entire sidewall portion (excluding the buttress portion).
As shown in FIG. 7, the noise suppressor 9 provided on the tire inner surface 7 in the sidewall portion has a substantially constant thickness T4 (mm), and in this example, T3 (=T1)>T4. However, T3=T4(=T1) may be satisfied, or T4(=T1)>T3 may be satisfied. The noise suppressor 9 provided on the tire inner surface 7 in the sidewall portion has a peripheral length L3 (mm). By definition, L1 (mm)=2×L3 (mm)+2×L4 (mm).
Also with the tire of the embodiment shown in FIG. 7, since the extending region of the noise suppressor 9 can be ensured so as to include the shoulder region S, the noise suppressing property can be improved, and the shoulder region S can be improved. Since the heat generation in the tire is relatively low, the noise suppressor 9 is separated from the tire inner surface 7 due to melting of the adhesive layer or the like, and heat is accumulated in the noise suppressor 9 to increase the temperature inside the tire. It is possible to suppress breakdown of members and improve durability of the tire.
Further, as in the embodiment shown in FIGS. 2, 5, and 6, the ratio T1/L1 is set to 0.2 or more and 0.8 or less. The ratio T1/L1 is preferably 0.3 or more and 0.6 or less.
For example, the thickness T1 of the noise damper 9 can be set to 5 to 40 mm in the range of the flattening ratio T1/L1.
In particular, in the tire of the embodiment shown in FIG. 7, compared to the embodiment shown in FIG. 6, the noise suppressor 9 is a buttress in which the deformation is relatively large in the narrow width/large diameter tire in the sidewall portion. Since it is not in contact with the tire inner surface 7 in the portion, it is possible to suppress the noise suppressor 9 from receiving a force due to the deformation and the heat transmitted from the buttress portion to the noise suppressor 9 as compared with the embodiment shown in FIG. It is also possible to secure a large volume of the noise suppressor 9 as compared with the embodiment shown in FIG. As a result, it is possible to better balance the noise control performance and the tire durability.
In the embodiment shown in FIG. 7, the region where the noise suppressor 9 is not provided on the tire inner surface 7 is the tire inner surface 7 of the buttress portion, but it may be another region in the sidewall portion.
In the embodiment shown in FIG. 7, the innermost end of the noise suppressor 9 in the tire radial direction is located outside of the outermost end of the bead filler 2b in the tire radial direction. According to this, heat transfer from the bead filler 2b, which is a member that generates a large amount of heat, to the noise suppressor 9 can be suppressed, and tire durability can be improved.
On the other hand, the noise suppressor 9 can be provided up to the tire inner surface 7 of the bead portion 2. For example, the innermost end of the noise suppressor 9 in the tire radial direction is closer to the tire outer diameter end than the outermost end of the bead filler 2b in the tire radial direction. It may be located inside the direction. In this case, it is possible to secure a larger volume of the sound damping body 9 and improve the sound damping property.

Further, in the present invention, as shown in FIG. 2, the noise suppressor 9 extends from the tire inner surface 7 in the shoulder region S in one half of the tire width direction to the tire in the shoulder region S in the other half of the tire width direction. It is preferable that both ends of the noise suppressor 9 in the direction along the tire inner surface 7 extend continuously to the inner surface 7 and that they are located in the shoulder regions S at both half portions in the tire width direction.
This is because it is possible to secure a large volume of the sound damping body 9 and further improve the sound damping property without lowering the tire durability.
Further, in the present invention, as shown in FIG. 5, the noise suppressor 9 extends from the tire inner surface 7 in the sidewall portion of one half portion in the tire width direction to the tire in the sidewall portion of the other half portion in the tire width direction. It is preferable that the both ends of the noise damper 9 extending in the direction along the tire inner surface 7 are located on the tire inner surface 7 in the sidewall portions of the tire width direction halves, respectively.
This is because it is possible to secure a larger volume of the sound damping body 9 and further improve the sound damping property without lowering the tire durability.
Further, in the present invention, as shown in FIG. 6, the noise suppressor 9 continuously extends from the tire inner surface 7 in the shoulder region S to the tire inner surface 7 in the sidewall portion in each half portion in the tire width direction. One end in the direction extending along the tire inner surface 7 of the noise suppressor 9 in each half of the tire width direction is located on the tire inner surface 7 in the shoulder region S, and the other end is the tire inner surface in the sidewall portion. It is preferably located at 7.
This is because it is possible to further improve tire durability by preventing the region where the noise suppressor 9 is provided from being applied to the center portion C where heat generation is relatively large.
Further, in the present invention, as shown in FIG. 7, the noise suppressor 9 intermittently extends in each half portion in the tire width direction from the tire inner surface 7 in the shoulder region S to the tire inner surface in the sidewall portion. It is preferable that the noise suppressor 9 is not provided on the tire inner surface 7 in the center region C and the tire inner surface 7 in the buttress portion in each half portion in the tire width direction.
This is because it is possible to further improve tire durability by preventing the region where the noise suppressor 9 is provided from being applied to the center portion where heat generation is relatively large and the buttress portion where deformation is large.
Further, in the present invention, the noise suppressor 9 is preferably a sponge material.
Since the sponge material has a small specific gravity, it is possible to improve the sound damping property while preventing an excessive increase in weight.

<Tire/rim assembly>
The tire/rim assembly here is one in which the pneumatic radial tire for passenger cars according to each of the embodiments of the first to third aspects is incorporated in a rim. According to the tire/rim assembly, it is possible to obtain the same operational effects as those described for the pneumatic radial tire for a passenger vehicle according to each of the embodiments of the first to third aspects. At this time, the internal pressure of the tire/rim assembly is preferably 200 kPa or more, more preferably 220 kPa or more, and further preferably 280 kPa or more. As described above, the higher the internal pressure of the tire is, the higher the ground pressure is in the center region C as compared with the shoulder region S, so that the above-described function and effect can be effectively obtained, and the high internal pressure By doing so, the rolling resistance can be further reduced. On the other hand, the internal pressure of the tire/rim assembly is preferably 350 kPa or less. This is because the riding comfort can be improved.

<How to use pneumatic radial tires for passenger cars>
The pneumatic radial tire for passenger cars used here is the pneumatic radial tire for passenger cars according to the respective embodiments of the first to third aspects. According to the method of using the pneumatic radial tire for a passenger vehicle, the same operational effects as those described for the pneumatic radial tire for a passenger vehicle according to the respective embodiments of the first to third aspects can be obtained. At this time, the internal pressure is preferably 200 kPa or more, more preferably 220 kPa or more, and further preferably 280 kPa or more. As described above, the higher the internal pressure of the tire is, the higher the ground pressure is in the center region C as compared with the shoulder region S, so that the above-described function and effect can be effectively obtained, and the high internal pressure By doing so, the rolling resistance can be further reduced. On the other hand, it is preferable to use the internal pressure of 350 kPa or less. This is because the riding comfort can be improved.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments. For example, in the embodiments shown in FIGS. 2 and 5 to 7, the noise suppressor 9 has a symmetrical structure with the tire equatorial plane CL as a boundary, but may have an asymmetric structure. For example, any one or more of the position, the extension region, the shape, the material, the maximum width, the maximum thickness, etc. of the noise suppressor 9 in one half of the tire width direction may be used to suppress the noise in the other half of the tire width direction. It can be different from the body 9. As an example, by different combinations of the above-described respective embodiments and the modifications thereof, the position, the extension region, and the like of the noise suppressor 9 in one half of the tire width direction may be changed to the noise suppressor 9 in the other half of the tire width direction. The position, the extension area, and the like can be different. Alternatively, for example, the noise suppressor 9 of each of the above-described embodiments and its modifications is provided only in one half of the tire width direction, and the noise suppressor 9 is not provided in the other half of the tire width direction. You can also
Further, when the noise suppressor 9 is divided in the tire circumferential direction, a part of the noise suppressor 9 is not in contact with or adhered to the inner surface of the tire in the center region, so that the above-described effect can be obtained. it can.

Here, in the tire/rim assembly, SW is less than 165 mm, the ratio SW/OD is 0.26 or less, the internal pressure is 200 kPa or more, and the oblateness is 70 or less, and It is preferable that the rim diameter is 18 inches or more, and the sound absorber (eg, sponge material) has a peripheral length of 1800 mm or more.
The "perimeter of the noise suppressor" here means the perimeter at the position where the circumference of the noise suppressor is minimized when measured in the tire circumferential direction, and the noise suppressor is divided into multiple parts. In the case of the sound damping body, it means the circumference of the sound damping body having the smallest circumference. Further, when the noise damper is divided in the tire circumferential direction, it means the total circumferential length.
In order to improve fuel efficiency, it is preferable to increase the internal pressure to reduce the rolling resistance, and it is also preferable to reduce the flatness to reduce the weight and suppress the tire deformation, and the tire cross section. It is also preferable to reduce the air resistance by narrowing the width.
On the other hand, when the internal pressure is set high, the ground contact pressure on the tread tread increases, and the cavity resonance tends to deteriorate. Further, when the flatness is lowered, the belt tension increases and the ground contact pressure on the tread tread increases, so that the cavity resonance tends to be deteriorated. Further, when the tire cross-sectional width is narrowed, the tread width is also narrowed accordingly, so that the cross-sectional area of the noise suppressor is generally reduced and the cavity resonance tends to be deteriorated.
Therefore, by increasing the outer diameter of the tire and increasing the circumferential length of the noise suppressor, it is possible to increase the total volume of the noise suppressor without increasing the cross-sectional area of the noise suppressor. Can be suppressed. Furthermore, since the noise suppressor has a small cross-sectional area, the amount of heat generated by the noise suppressor can be suppressed.
As described above, according to the above configuration, it is possible to achieve a high level of both cavity resonance reduction, rolling resistance reduction, and heat generation endurance performance.
Similarly, the tire/rim assembly has SW of 165 mm or more, satisfies OD (mm)≧2.135×SW (mm)+282.3, and has an internal pressure of 200 kPa or more, and a flatness Is 70 or less, the rim diameter is 18 inches or more, and the peripheral length of the noise damper (eg, sponge material) is 1800 mm or more.
Similarly, the tire/rim assembly satisfies OD (mm)≧−0.0187×SW(mm) ² +9.15×SW(mm)−380, and has an internal pressure of 200 kPa or more, Further, it is preferable that the flatness is 70 or less, the rim diameter is 18 inches or more, and the circumferential length of the noise damper (eg, sponge material) is 1800 mm or more.

1: Pneumatic radial tires (tires) for passenger cars,
2: bead portion, 2a: bead core, 2b: bead filler, 3: carcass,
4: belt, 4a, 4b: belt layer, 5: tread,
6: circumferential main groove, 7: tire inner surface, 8: inner liner,
9: Suppressor,
CL: tire equatorial plane, E: ground contact edge,
C: Center area, S: Shoulder area

Claims

A pneumatic radial tire for a passenger vehicle, which comprises a carcass consisting of a ply of a radial arrangement cord, straddling toroidally between a pair of bead portions,
The sectional width SW of the tire is less than 165 (mm), the ratio SW/OD of the sectional width SW (mm) and the outer diameter OD (mm) of the tire is 0.26 or less,
The inner surface of the tire is provided with one or more noise dampers,
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a no-load state, a tire width direction region of the tire width direction center 50% between ground contact ends is defined as a center region, and the center When the tire width direction area of 25% outside the area in the tire width direction is set as the shoulder area,
The noise damper is provided at least on the inner surface of the tire in the shoulder region,
In the tire width direction cross section, when the peripheral length of the noise suppressor along the inner surface of the tire is L1 (mm), the measurement is performed in a direction orthogonal to the direction of the noise suppressor along the inner surface of the tire. A pneumatic radial tire for passenger cars, characterized in that the ratio T1/L1 is 0.2 or more and 0.8 or less when the maximum thickness is T1 (mm).
A pneumatic radial tire for a passenger vehicle, which comprises a carcass consisting of a ply of a radial arrangement cord, straddling toroidally between a pair of bead portions,
The sectional width SW of the tire is 165 (mm) or more, and the sectional width SW (mm) and the outer diameter OD (mm) of the tire are expressed by a relational expression,
OD (mm)≧2.135×SW (mm)+282.3
The filling,
The inner surface of the tire is provided with one or more noise dampers,
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a no-load state, a tire width direction region of the tire width direction center 50% between ground contact ends is defined as a center region, and the center When the tire width direction area of 25% outside the area in the tire width direction is set as the shoulder area,
The noise damper is provided at least on the inner surface of the tire in the shoulder region,
In the tire width direction cross section, when the peripheral length of the noise suppressor along the inner surface of the tire is L1 (mm), the measurement is performed in a direction orthogonal to the direction of the noise suppressor along the inner surface of the tire. A pneumatic radial tire for passenger cars, characterized in that the ratio T1/L1 is 0.2 or more and 0.8 or less when the maximum thickness is T1 (mm).
A pneumatic radial tire for a passenger vehicle, which comprises a carcass consisting of a ply of a radial arrangement cord, straddling toroidally between a pair of bead portions,
The sectional width SW (mm) and outer diameter OD (mm) of the tire are expressed by a relational expression,
OD (mm) ≥-0.0187 x SW (mm) 2 +9.15 x SW (mm)-380
The filling,
The inner surface of the tire is provided with one or more noise dampers,
In the tire width direction cross section when the tire is incorporated into a rim, filled with a specified internal pressure, and in a no-load state, a tire width direction region of the tire width direction center 50% between ground contact ends is defined as a center region, and the center When the tire width direction area of 25% outside the area in the tire width direction is set as the shoulder area,
The noise damper is provided at least on the inner surface of the tire in the shoulder region,
In the tire width direction cross section, when the peripheral length of the noise suppressor along the inner surface of the tire is L1 (mm), the measurement is performed in a direction orthogonal to the direction of the noise suppressor along the inner surface of the tire. A pneumatic radial tire for passenger cars, characterized in that the ratio T1/L1 is 0.2 or more and 0.8 or less when the maximum thickness is T1 (mm).
The sound damper extends continuously from the inner surface of the tire in the shoulder region of one half of the tire width direction to the inner surface of the tire in the shoulder region of the other half of the tire width direction,
4. The pneumatic passenger vehicle according to any one of claims 1 to 3, wherein both ends of the noise suppressor in a direction along an inner surface of the tire are located in the shoulder regions of both half portions in a tire width direction, respectively. Radial tires.
The sound damper extends continuously from the inner surface of the tire in the sidewall portion of one half of the tire width direction to the inner surface of the tire in the sidewall portion of the other half of the tire width direction,
The both ends of the noise suppressor in the direction along the inner surface of the tire are respectively located on the inner surface of the tire in the sidewall portions of both half portions in the tire width direction, according to any one of claims 1 to 3. Pneumatic radial tires for passenger cars.
The noise suppressor, in each half of the tire width direction, from the inner surface of the tire in the shoulder region to the inner surface of the tire in the sidewall portion, respectively, extending continuously,
One end in the direction along the inner surface of the tire of the noise suppressor in each half of the tire width direction is located on the inner surface of the tire in the shoulder region, and the other end of the tire in the sidewall portion. The pneumatic radial tire for passenger cars according to any one of claims 1 to 3, which is located on the inner surface.
The noise suppressor, in each half portion in the tire width direction, from the inner surface of the tire in the shoulder region to the inner surface of the tire in the sidewall portion, each extending intermittently,
4. The noise suppressor according to claim 1, wherein, in each half of the tire width direction, the noise suppressor is not provided on an inner surface of the tire in the center region and an inner surface of the tire in a buttress portion. Pneumatic radial tires for passenger cars.
The pneumatic radial tire for passenger cars according to any one of claims 1 to 7, wherein the noise damper is a sponge material.