JP2021046128A - Pneumatic tire - Google Patents

Abstract

To provide a pneumatic tire which inhibits deterioration of puncture resistance.SOLUTION: A pneumatic tire according to the invention includes a tread part. A sound control body is disposed on a tire inner surface in the tread part through a sealant layer. The sound control body has a first groove part, extending in a tire circumferential direction, and second groove parts, communicating with the first groove part and extending in a tire width direction, on a sealant layer side surface.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pneumatic tire.

Conventionally, in order to reduce the resonance vibration (cavity resonance) of air or gas generated in the cavity of a tire, it is known to arrange a sound control body made of a sponge material or the like on the inner surface of the tire (for example, Patent Document). 1). The sound control body can convert the vibration energy of air or gas in the tire cavity into thermal energy and suppress the cavity resonance in the tire cavity.

Japanese Unexamined Patent Publication No. 2005-254924

Here, in order to close the hole at the time of tire puncture, a sealant layer may be arranged on the inner surface of the tire. In such a case, the nail penetrates the tread part and the sound control body is torn, and the torn part enters the hole created by the penetration of the nail, so that the sealant cannot flow into the hole well. There was a risk. Further, when the sound control body is a sponge material, the sealant agent may be absorbed by the sponge and the fluidity of the sealant agent may decrease. When such a phenomenon occurs, the puncture resistance may be deteriorated.

Therefore, an object of the present invention is to provide a pneumatic tire in which a decrease in puncture resistance is suppressed.

The gist structure of the present invention is as follows.
(1) The pneumatic tire of the present invention
Equipped with a tread part
A sound control body is arranged on the inner surface of the tire in the tread portion via a sealant layer.
The sound control body is characterized by having a first groove portion extending in the tire circumferential direction and a second groove portion communicating with the first groove portion and extending in the tire width direction on the surface on the sealant layer side. To do.

(2) In the above (1), the first groove portion extends along the tire circumferential direction or is inclined at an inclination angle of 30 ° or less with respect to the tire circumferential direction, and the second groove portion extends. It is preferable that the groove portion extends along the tire width direction or is inclined and extends at an inclination angle of 30 ° or less with respect to the tire width direction.

(3) In the above (1) or (2),
The first groove portion is formed in the central portion in the tire width direction, and the first groove portion is formed.
It is preferable that the sound control body is formed in an arch shape in a cross-sectional view in the tire width direction.

(4) In the above (3), it is also preferable that the sound control body is curved so as to be convex from the outside in the tire radial direction to the inside in the cross-sectional view in the tire width direction.

(5) In any of the above (1) to (4),
A plurality of the second groove portions are arranged in the tire circumferential direction at each of the end portions on one side and the other side in the tire width direction of the sound control body.
The second groove on one end in the tire width direction and the second groove on the other end in the tire width direction do not have a portion that overlaps each other when projected in the tire width direction. It is preferable that the tires are arranged so as to be out of phase in the tire circumferential direction.

(6) In (5) above,
The tire circumferential length of the second groove is preferably shorter than the tire circumferential length of the sound control body between the two adjacent second grooves in the tire circumferential direction.

According to the present invention, it is possible to provide a pneumatic tire in which a decrease in puncture resistance is suppressed.

It is a tire width direction sectional view of the pneumatic tire which concerns on one Embodiment of this invention. It is sectional drawing of the sound control body of FIG. It is sectional drawing of the sound control body which concerns on another example.

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

FIG. 1 is a cross-sectional view of a pneumatic tire according to an embodiment of the present invention in the tire width direction. FIG. 1 shows a cross section in the tire width direction in a state where a pneumatic tire (hereinafter, also simply referred to as a tire) is attached to an applicable rim, the specified internal pressure is applied, and no load is applied.
Here, the "applicable rim" is an industrial standard that is effective in the area where tires are produced and used. In Japan, JATMA (Japan Automobile Tire Association) JATMA YEAR BOOK, and in Europe, ETRTO (The European Tire and). STANDARDS MANUAL of Rim Technical Organization), YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States, etc. Rim, TRA's YEAR BOOK refers to Tire Rim) (ie, the "rim" above includes sizes that may be included in the industry standards in the future in addition to the current size. As an example, the size described as "FUTURE DEVELOPMENTS" in the ETRTO 2013 edition can be mentioned.) However, in the case of a size not described in the above industrial standard, the width corresponding to the bead width of the tire. Refers to the rim of.
In addition, 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 / ply rating described in the above JATMA, etc., and is of a size not described in the above industrial standard. In this case, the "specified internal pressure" shall mean the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tires are mounted.

As shown in FIG. 1, the pneumatic tire (hereinafter, also simply referred to as a tire) 1 of the present embodiment includes a pair of bead portions 2, a pair of sidewall portions connected to the bead portions, and a pair of sidewall portions connected to the sidewall portions. It has a tread portion 5. Further, the tire 1 is provided with a belt 4 and a tread rubber in this order on the outer side in the tire radial direction of the crown portion of the carcass 3 straddling the bead core 2a embedded in the pair of bead portions 2 in a toroidal shape.

As shown in FIG. 1, in the present embodiment, a bead filler 2b having a substantially triangular cross section in the illustrated example is further provided on the outer side of the bead core 2a in the tire radial direction. On the other hand, in the present invention, the configuration of the bead portion 2 is not particularly limited, and the cross-sectional shape, size, and material of the bead core 2a and the bead filler 2b can be any known one. Further, the configuration may not have a bead core 2a or a bead filler 2b.

Further, in the present embodiment, the carcass 3 is composed of one carcass ply made of organic fibers, but in the present invention, the number and materials of the carcass ply constituting the carcass 3 are not particularly limited.

Further, in the present embodiment, the belt 4 is composed of two layers of belt layers 4a and 4b in which cords (steel cords in this example) intersect each other between layers, but in the present invention, the belt structure is not particularly limited. Any configuration can be used such as the material of the cord, the number of driving, the inclination angle, the number of belt layers, and the like.
Further, the material of the rubber of the tread portion 5 and the like can be any known configuration.

FIG. 2 is a cross-sectional view of the sound control body of FIG. FIG. 2 shows a cross section on the sealant layer side in which the first groove portion is formed in the tire radial direction.
As shown in FIGS. 1 and 2, in the tire of the present embodiment, the sound control body 7 is provided on the inner surface 6 of the tire in the tread portion 5 (further inner surface of the inner liner (not shown in this example)) via the sealant layer 8. Have been placed.

In the present embodiment, in the sound control body 7, at least a part (all in the illustrated example) of the tire width direction extending region is arranged inside the tire radial direction of the tread portion 5. In the illustrated example, the width of the sealant layer 8 in the tire width direction is larger than the width of the sound control body 7 in the tire width direction, but can be the same or smaller.
In this example, the sound control body 7 and the sealant layer 8 are continuously provided on the tire circumference along the tire peripheral direction. On the other hand, the sound control body 7 and the sealant layer 8 may be provided intermittently on the tire circumference along the tire circumference direction.

For the sealant layer 8, a sealant liquid which is an adhesive fluid can be used, and for example, a conventionally known sealant for puncture sealing can be used. As the sealant, for example, a silicone compound, a styrene compound, a urethane compound, an ethylene compound, a gel sheet containing polybutene and a terpene resin as main components, or the like can be used.

In the present embodiment, the sound control body 7 is a porous body (sponge material in this example). In this example, the sound control body 7 has a substantially rectangular shape in a cross-sectional view in the tire width direction, but the shape of the sound control body 7 is not particularly limited. The size of the sound control body 7 is not particularly limited, but the volume of the sound control body 7 is preferably 0.1% to 80% of the total volume of the lumen of the tire 1. The volume of the sound control body 7 can be set to 0.1% or more of the total volume of the cavity of the tire 1 to enhance the sound control property, while the volume of the sound control body 7 can be set to the total volume of the cavity of the tire 1. This is because the weight increase due to the sound control body 7 can be suppressed to 80% or less. The "volume" referred to here is defined as a state in which the tire 1 is removed from the rim at normal temperature and pressure. Further, the "total product of the tire lumen" means the total product when the tire 1 is attached to the applicable rim and the specified internal pressure is applied.

When the sound control body 7 is a sponge material, the sponge material can be a sponge-like porous structure, and includes, for example, a so-called sponge having open cells in which rubber or synthetic resin is foamed. Further, the sponge material includes, in addition to the above-mentioned sponge, a web-like material in which animal fibers, plant fibers, synthetic fibers and the like are entwined and integrally connected. The above-mentioned "porous structure" is not limited to a structure having open cells, but also includes a structure having closed cells. The sponge material as described above converts the vibration energy of air in which the voids formed on the surface or inside vibrate into heat energy. As a result, cavity resonance in the tire cavity is suppressed, and as a result, road noise can be reduced.
Examples of the sponge material include synthetic resin sponges such as ether-based polyurethane sponges, ester-based polyurethane sponges, and polyethylene sponges, chloroprene rubber sponges (CR sponges), ethylene propylene diene rubber sponges (EPDM sponges), and nitrile rubber sponges (NBR). A rubber sponge such as sponge) can be mentioned. From the viewpoints of sound control, lightness, adjustable foaming, durability and the like, it is preferable to use a polyurethane-based sponge containing an ether-based polyurethane sponge or a polyethylene-based sponge.

When the sound control body 7 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 5 to 450 N. By setting the hardness to 5 N or more, the sound control property can be improved, while by setting the hardness to 450 N or less, the adhesive force of the sound control body can be increased. Similarly, the hardness of the sound control body is more preferably in the range of 8 to 300 N. Here, the "hardness" is a value measured in accordance with the method A of item 6.3 of the measurement methods of item 6 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 control property can be improved, while by setting the specific gravity of the sponge material to 0.090 or less, the weight increase due to the sponge material can be suppressed. Because it can be done. 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 the specific gravity in accordance with the measurement method of paragraph 5 of JIS K6400.
The tensile strength of the sponge material is preferably 20 to 500 kPa. This is because the adhesive strength can be improved by setting the tensile strength to 20 kPa or more, while the productivity of the sponge material can be improved by setting the tensile strength to 500 kPa or less. Similarly, the tensile strength of the sponge material is more preferably 40 to 400 kPa. Here, the "tensile strength" is a value measured with a No. 1 dumbbell-shaped test piece in accordance with the measurement method of Section 10 of JIS K6400.
Further, 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 by setting the elongation at break to 800% or less, the productivity of the sponge material can be improved. 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 measurement method of Section 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 occurrence of cracks in the sponge material, while by setting the tear strength to 130 N / cm or less, the manufacturability of the sponge material can be improved. 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 test piece in accordance with the measurement method of Section 11 of JIS K6400.
The foaming rate of the sponge material is preferably 1% or more and 40% or less. This is because the sound control property can be improved by setting the foaming rate to 1% or more, while the productivity of the sponge material can be improved by setting the foaming rate to 40% or less. Similarly, the foaming rate of the sponge material is more preferably 2 to 25%. Here, the "foaming ratio" 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 total mass of the sponge material is preferably 5 to 800 g. This is because the sound control property can be reduced by setting the mass to 5 g or more, while the weight increase due to the sponge material can be suppressed by setting the mass to 800 g or less. Similarly, the mass of the sponge material is preferably 20 to 600 g.

Here, as shown in FIGS. 1 and 2, in the tire of the present embodiment, the sound control body 7 has a first groove portion 9 extending in the tire circumferential direction on the surface of the sealant layer 8 side and the first groove portion 9. It has a second groove portion 10 that communicates with the groove portion 9 and extends in the tire width direction.

In this example, the first groove portion 9 extends along the tire circumferential direction, and the second groove portion 10 extends along the tire width direction.
The width (maximum width) of the first groove 9 in the tire width direction is not particularly limited, but may be 80 to 90% of the width (maximum width) of the sound control body 9 in the tire width direction. When it is 80% or more, the fluidity of the sealant can be further increased, while when it is 90% or less, the decrease in the volume of the sound control body is suppressed and the sound control property is ensured. Because it can be done.
The height (maximum height) of the first groove portion 9 is not particularly limited, but may be 15 to 60% of the thickness (maximum thickness) of the sound control body 7. By setting it to 15% or more, the fluidity of the sealant can be further increased, while by setting it to 60% or less, the decrease in the volume of the sound control body is suppressed to ensure the sound control property. Because it can be done.
The length (maximum length) of the second groove portion 10 in the tire circumferential direction is not particularly limited, but may be 5 to 20 mm. When it is 5 mm or more, the fluidity of the sealant can be further increased, while when it is 20 mm or less, the decrease in the volume of the sound control body can be suppressed and the sound control property can be ensured. Because.
The height (maximum height) of the second groove portion 10 is not particularly limited, but may be 10 to 60% of the thickness (maximum thickness) of the sound control body 7. By setting it to 10% or more, the fluidity of the sealant can be further increased, while by setting it to 60% or less, the decrease in the volume of the sound control body is suppressed to ensure the sound control property. Because it can be done.

As shown in FIGS. 1 and 2, in this example, the first groove portion 9 is formed in the central portion in the tire width direction, and as shown in FIG. 1, the sound control body 7 is arched in the cross-sectional view in the tire width direction. It is formed in a shape. In this example, in the cross section in the tire width direction, the first groove portion 9 has a rectangular cross section, and the end portion in the tire width direction of the sound control body 7 (in this example, one of the tire width directions in the illustrated tire width direction cross section). Only the end) is in contact with the tire inner surface 6 (sealing layer 8 in this example).
Hereinafter, the action and effect of the pneumatic tire of the present embodiment will be described.

According to the pneumatic tire of the present embodiment, first, since the sound control body 7 is arranged on the inner surface 6 of the tire, the sound control property can be improved. Further, since the sealant layer 8 is arranged on the inner surface 6 of the tire, the hole can be closed when the tire is punctured.
Then, the sound control body 7 has a first groove portion 9 extending in the tire circumferential direction and a second groove portion 10 communicating with the first groove portion 9 and extending in the tire width direction on the surface on the sealant layer 8 side. Therefore, when the tire is punctured, the sealant can flow through the first groove 9 and the second groove 10 communicating with the first groove 9 as a passage, so that the sealant 7 (sponge material). ), The fluidity of the sealant can be increased in the tire circumferential direction and the tire width direction.
Further, since the sound control body 7 is not in contact with the sealant layer 8 at the place where the first groove portion 9 and the second groove portion 10 are formed, the nail does not reach the sound control body 7, and the sound control body 7 is torn. It is possible to suppress the phenomenon that the sound body 7 enters the hole generated by the penetration of the nail.
As described above, according to the pneumatic tire of the present embodiment, it is possible to suppress the deterioration of the puncture resistance performance.

Here, the first groove portion extends along the tire circumferential direction, or is inclined and extends at an inclination angle of 30 ° or less with respect to the tire circumferential direction, and the second groove portion extends along the tire width direction. It is preferable that the tire extends at an inclination angle of 30 ° or less with respect to the tire width direction. This is because the fluidity of the sealant can be further increased in the tire circumferential direction and the tire width direction within the above range.

Further, it is preferable that the first groove portion is formed in the central portion in the tire width direction, and the sound control body is formed in an arch shape in the cross-sectional view in the tire width direction. This is because it is possible to suppress the deterioration of the puncture resistance performance as described above while arranging the sound control body in a structurally stable manner.

Further, it is also preferable that the sound control body is curved so as to be convex from the outside in the tire radial direction to the inside in the cross-sectional view in the tire width direction. In this case, the first groove portion can have a substantially semicircular cross section. Sound control because the first groove (approximately semicircular) functions as a space that is not easily crushed by centrifugal force during running (especially during high-speed running) and can be displaced when subjected to centrifugal force. This is because the decrease in the volume of the body can be suppressed and the sound control property can be further improved.

Here, as shown in FIG. 2, a plurality of second groove portions are arranged in the tire circumferential direction at each of the end portions of the sound control body on one side and the other side in the tire width direction, and are arranged on one side in the tire width direction. The phase in the tire circumferential direction is shifted so that the second groove on the end and the second groove on the other end in the tire width direction do not overlap each other when projected in the tire width direction. It is preferably arranged. While ensuring the volume of the sound control body, the sound control body and the tire inner surface (sealant layer) are in continuous contact with each other when viewed in the tire circumferential direction, so that the sound control body and the tire inner surface (sealant layer) are in contact with each other. This is because the adhesiveness can be improved.
FIG. 3 is a cross-sectional view of the sound control body according to another example. FIG. 3 shows a cross section on the sealant layer side in which the first groove portion is formed in the tire radial direction.
On the other hand, from the viewpoint of further increasing the fluidity of the sealant in the tire width direction, as shown in FIG. 3, a plurality of sound control bodies are provided at the ends on one side and the other side in the tire width direction. When the second grooves are arranged in the tire circumferential direction and the second groove on one end in the tire width direction and the second groove on the other end in the tire width direction are projected in the tire width direction. It can also be arranged so as to have portions overlapping each other.

Here, as shown in FIG. 2, the tire circumferential length A of the second groove portion is shorter than the tire circumferential length B of the sound control body between the two second groove portions adjacent to the tire circumferential direction. Is preferable. This is because the volume of the sound control body can be secured to further secure the sound control property.
On the other hand, from the viewpoint of further ensuring the fluidity of the sealant, as shown in FIG. 3, the tire circumferential length A of the second groove is between the two second grooves adjacent to the tire circumferential direction. It is also preferable that the length of the sound control body is longer than the tire circumferential length B.
Further, the tire circumferential length A and the tire circumferential length B can be the same.

The contour line of the sound control body partitioned by the second groove may be rectangular in the side view from the tire width direction, but is preferably arcuate. This is because the arc-shaped sound control body having the second groove portion is less likely to be crushed by the centrifugal force during traveling (particularly during high-speed traveling), and the sound control property can be further 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 example shown in FIG. 1, the end portion of the sound control body in the tire width direction is the belt end (the end in the tire width direction of one belt layer or the belt layer having the maximum width among two or more belt layers. Although it is in contact with the tire inner surface 6 (sealing layer 8 in the illustrated example) on the inner side in the tire width direction from the end in the tire width direction), the end portion in the tire width direction of the sound control body is on the outer side in the tire width direction from the belt end. It may be in contact with the sealant layer). Various other modifications are possible.

1: Pneumatic tire 2: Bead part 2a: Bead core 2b: Bead filler 3: Carcass 4: Belt 5: Tread part 6: Tire inner surface 7: Sound control body 8: Sealant layer 9: First groove part 10: Second groove part

Claims (6)

Equipped with a tread part
A sound control body is arranged on the inner surface of the tire in the tread portion via a sealant layer.
The sound control body is characterized by having a first groove portion extending in the tire circumferential direction and a second groove portion communicating with the first groove portion and extending in the tire width direction on the surface on the sealant layer side. Pneumatic tires. The first groove portion extends along the tire circumferential direction, or is inclined and extends at an inclination angle of 30 ° or less with respect to the tire circumferential direction, and
The pneumatic tire according to claim 1, wherein the second groove extends along the tire width direction or is inclined at an inclination angle of 30 ° or less with respect to the tire width direction. The first groove portion is formed in the central portion in the tire width direction, and the first groove portion is formed.
The pneumatic tire according to claim 1 or 2, wherein the sound control body is formed in an arch shape in a cross-sectional view in the tire width direction. The pneumatic tire according to claim 3, wherein the sound control body is curved so as to be convex from the outside to the inside in the tire radial direction in a cross-sectional view in the tire width direction. A plurality of the second groove portions are arranged in the tire circumferential direction at each of the end portions on one side and the other side in the tire width direction of the sound control body.
The second groove on one end in the tire width direction and the second groove on the other end in the tire width direction do not have a portion that overlaps each other when projected in the tire width direction. The pneumatic tire according to any one of claims 1 to 4, wherein the tires are arranged so as to be out of phase in the tire circumferential direction. The pneumatic tire according to claim 5, wherein the tire circumferential length of the second groove is shorter than the tire circumferential length of the sound control body between the two adjacent second grooves in the tire circumferential direction.

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