JP7703407B2 - Pneumatic tires - Google Patents

Description

The present invention relates to a pneumatic tire.

Conventionally, pneumatic tires are known that incorporate communication devices such as RF (Radio Frequency) tags that have memories for reading and writing data for tire manufacturing management, shipping management, usage history management, etc. (see, for example, Patent Document 1). Patent Document 1 proposes covering the communication device with rubber that has a higher elastic modulus than the rubber that constitutes the adjacent members as a method for suppressing distortion of the communication device.

JP 2016-037235 A

However, in recent years, there has been an increasing demand to suppress the strain on communication devices. In particular, there are cases where the rubber that constitutes the tire is made thinner due to demands for lighter tires. In such cases, the strain on the communication device placed inside the rubber tends to be large, so there is a demand to reduce the strain even further.

The present invention aims to provide a pneumatic tire that suppresses distortion of the built-in communication device.

The gist and configuration of the present invention are as follows.
(1) A pneumatic tire incorporating a communication device member in which the communication device is rubber-covered,
the communication device member includes a first covering rubber that covers the communication device, and a second covering rubber that covers an outer periphery of the first covering rubber,
A pneumatic tire, wherein the elastic modulus E2 of the second covering rubber is smaller than the elastic modulus E1 of the first covering rubber.
The term "elastic modulus" as used herein refers to a value obtained by performing a tensile test in accordance with JIS K 6251 and measuring the tensile stress at 25% elongation.

(2) A pneumatic tire as described in (1) above, in which the ratio E1/E2 is 2 or more and 10 or less.

(3) The elastic modulus E1 of the first covering rubber is greater than the elastic modulus E3 of the rubber of the tire constituent member adjacent to the communication device member,
The pneumatic tire according to the above (1) or (2), wherein the elastic modulus E2 of the second covering rubber is smaller than the elastic modulus E3 of the rubber of the tire constituent member adjacent to the communication device member.

(4) A pneumatic tire according to (3) above, in which the ratio E1/E3 is 1.42 or more and 2.85 or less.

(5) A pneumatic tire according to claim (3) or (4), in which the ratio E2/E3 is 0.28 or more and 0.71 or less.

(6) When the pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and unloaded, the ratio V of the volume V2 of the second covering rubber to the volume V1 of the first covering rubber is
The pneumatic tire according to any one of (1) to (5) above, wherein 2/V1 is 0.26 or greater and 0.35 or less.
Here, the term "applicable rim" refers to a standard rim for the applicable size that is an industrial standard effective in the region where the tire is manufactured and used, and is described or will be described in the future in the JATMA YEAR BOOK of the Japan Automobile Tire Manufacturers Association (JATMA) in Japan, the STANDARDS MANUAL of the European Tire and Rim Technical Organization (ETRTO) in Europe, and the YEAR BOOK of the Tire and Rim Association, Inc. (TRA) in the United States. The term "rim" refers to a rim having a width corresponding to the bead width of the tire (i.e., the above "rim" includes not only current sizes but also sizes that may be included in the above industry standard in the future. Examples of "sizes to be described in the future" include sizes described as "FUTURE DEVELOPMENTS" in the 2013 edition of ETRTO). However, in the case of a size not described in the above industry standard, the term refers to a rim having a width corresponding to the bead width of the tire.
In addition, the "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity of a single wheel for the applicable size and ply rating as described in the above-mentioned JATMA etc., and in the case of a size not described in the above-mentioned industrial standards, the "specified internal pressure" refers to the air pressure (maximum air pressure) corresponding to the maximum load capacity specified for each vehicle on which the tire is mounted.

(7) A pneumatic tire according to any one of (1) to (6) above, in which the communication device is an RF tag having one or more antennas for transmitting and/or receiving electromagnetic waves and an IC chip having a memory unit.

The present invention provides a pneumatic tire that suppresses distortion of the built-in communication device.

1 is a schematic cross-sectional view in the tire width direction of a pneumatic tire according to one embodiment of the present invention. FIG. 2 is a schematic diagram of communication device components.

The following describes in detail an embodiment of the present invention with reference to the drawings.

Figure 1 is a cross-sectional view in the tire width direction of a pneumatic tire according to one embodiment of the present invention. As shown in Figure 1, this tire 1 includes a pair of bead portions 2, a carcass 3 that spans the pair of bead portions 2 in a toroidal shape, a belt 4 consisting of one or more belt layers that is arranged on the tire radial outer side of the crown portion of the carcass 3, and a tread 5 that is arranged on the tire radial outer side of the belt 4.

In the illustrated example, a bead core 2a is embedded in the bead portion 2, and a bead filler 2b with a roughly triangular cross section is disposed on the radially outer side of the bead core 2a.

In the illustrated example, the carcass 3 is made up of one or more carcass plies. The carcass 3 is made up of a carcass main body 3a that spans a pair of bead portions 2 in a toroidal shape, and a carcass folded-up portion 3b that extends from the carcass main body 3a and is folded back around the bead core 2a. In the illustrated example, the end of the carcass folded-up portion 3b terminates radially outward of the radially outer end of the bead filler 2b, but this is not limited to this case. The cords of the carcass ply are not particularly limited, but organic fiber cords can be used.

In the illustrated example, the belt 4 is an inclined belt consisting of two belt layers 4a and 4b, with the belt cords extending between the layers crossing each other. The angle of the belt cords with respect to the tire circumferential direction is not particularly limited, but can be, for example, 15° to 60°. The number of belt layers is also not particularly limited, as long as it is one or more. The material of the belt cords is not particularly limited, but can be a steel cord.

In the illustrated example, the tread 5 is made of one layer of tread rubber, but it can also be formed as a tread having multiple layers of rubber in the tire radial direction or tire width direction. In the illustrated example, the tread 5 has three circumferential main grooves 6, but there is no particular limit to the number of circumferential main grooves, groove width, groove depth, groove shape, etc.

In the illustrated example, an inner liner 8 is disposed on the inner surface 7 of the tire. This prevents air and gas from passing through.

Figure 2 is a schematic diagram of the communication device member. As shown in Figures 1 and 2, the tire 1 has built-in communication device members 9, each of which is formed by rubber-coating a communication device 10 with a coating rubber 13, in each half of the tire width direction bounded by the tire equatorial plane CL. Note that it is sufficient for the tire 1 to have one or more communication device members 9 built in.

The communication device 10 performs wireless communication. In the illustrated example, the communication device 10 is an RF tag that has one or more antennas 12 (two in the illustrated example) that transmit and/or receive electromagnetic waves, and an IC chip 11 that has a memory unit.

In this example, the IC chip 11 has a storage unit which is any known memory and a control unit which is any known processor. The antenna 12 is connected to the IC chip 11 and extends in a straight line, a wavy line, or a spiral. In this example, two antennas 12 extend in opposite directions. The IC chip 11 may be operated by induced electromotive force generated by electromagnetic waves received by one or more antennas 12. That is, the communication device 10 may be a passive communication device. Alternatively, the communication device 10 may further include a battery and be capable of communicating by generating electromagnetic waves using its own power. That is, the communication device 10 may be an active communication device. Data such as tire manufacturing management, shipping management, and usage history management stored in the storage unit can be read, or data can be written to the storage unit.

In this embodiment, the communication device member 9 is disposed in the sidewall of the tire. In this example, the communication device member 9 is located radially outward from the end of the carcass folded portion 3b, but is located radially inward from the maximum tire width portion (the portion where the tire width in the tire width direction is maximum in the cross-sectional view of FIG. 1). This makes it possible to suppress the carcass from interfering with the transmission and reception of electromagnetic waves, and to increase the durability of the communication device member by avoiding the vicinity of the buttress portion where deformation is large. On the other hand, the arrangement of the communication device member 9 is not limited to this example, and the communication device member 9 may be located radially inward from the end of the carcass folded portion 3b. Also, the communication device member 9 may be located radially outward from the maximum tire width portion.

As shown in FIG. 2, the covering rubber 13 that covers the communication device is made of two types of rubber 14, 15. That is, the communication device member 9 has a first covering rubber 14 that (directly) covers the communication device 10, and a second covering rubber 15 that covers the outer periphery of the first covering rubber 14.

In the illustrated example, the first covering rubber 14 completely surrounds the entire outer periphery of the communication device 10, and all parts of the communication device 10 are in contact with the first covering rubber 14. In the illustrated example, the first covering rubber 14 is substantially elliptical in cross section (with the portion for the communication device 10 cut out), but the shape of the first covering rubber 14 is not limited to this and can be any shape, for example, it can be substantially rectangular in cross section (with the portion for the communication device 10 cut out).

In the illustrated example, the second covering rubber 15 completely surrounds the entire outer periphery of the first covering rubber 14, and all parts of the outer periphery of the first covering rubber 14 are in contact with the second covering rubber 15. In the illustrated example, the second covering rubber 15 is annular in cross section (i.e., the first covering rubber 14 and the communication device 10 are hollowed out), but the shape of the second covering rubber 15 is not limited to this and can be any shape, for example, the outer periphery can be approximately rectangular (however, the first covering rubber 14 and the communication device 10 are hollowed out). The shape of the inner periphery of the second covering rubber 15 corresponds to the shape of the outer periphery of the first covering rubber 14.

In the tire of this embodiment, the elastic modulus E2 of the second covering rubber 15 is smaller than the elastic modulus E1 of the first covering rubber 14 .
The effects of the pneumatic tire of the present embodiment will be described below.

According to the pneumatic tire of this embodiment, first, since the communication device 10 is covered with the first covering rubber 14, the first covering rubber 14 can suppress the deformation occurring in the tire from being transmitted to the communication device 10. Then, since the first covering rubber 14 is also covered with the second covering rubber 15 having a small elastic modulus, the deformation occurring in the tire can be dispersed by the second covering rubber 15. In this way, the deformation occurring in the tire is dispersed by the second covering rubber 15 and transmitted to the first covering rubber 14, and the first covering rubber 14 suppresses the dispersed deformation from being transmitted to the communication device 10, so that the distortion applied to the communication device can be effectively suppressed.
As described above, according to the pneumatic tire of the present embodiment, it is possible to suppress distortion of the built-in communication device.

Here, it is preferable that the ratio E1/E2 is 2 or more and 10 or less. By making the ratio E1/E2 2 or more, the deformation occurring in the tire can be further dispersed and/or the deformation can be prevented from being transmitted to the communication device, so that the distortion on the communication device can be further suppressed. Also, by making the ratio E1/E2 10 or less, the difference in rigidity between the first covering rubber 14 and the second covering rubber 15 can be prevented from becoming too large, so that failures and the like occurring at the interface between them can be suppressed.

Moreover, it is preferable that the elastic modulus E1 of the first covering rubber 14 is greater than the elastic modulus E3 of the rubber of the tire constituent member adjacent to the communication device member 9 (sidewall rubber in this embodiment), and the elastic modulus E2 of the second covering rubber 15 is less than the elastic modulus E3 of the rubber of the tire constituent member adjacent to the communication device member 9 (sidewall rubber in this embodiment). By making the elastic modulus E1 greater than the elastic modulus E3, it is possible to further prevent deformation from being transmitted to the communication device, and by making the elastic modulus E2 smaller than the elastic modulus E3, it is possible to further disperse deformation occurring in the tire. This is because it is possible to further suppress the distortion applied to the communication device.
In this embodiment, the tire component adjacent to the communication device member 9 is a sidewall rubber, but may also be a coating rubber of the carcass ply or a reinforcing rubber such as a chafer rubber.

Here, the ratio E1/E3 is preferably 1.42 or more and 2.85 or less. When the ratio E1/E3 is 1.42 or more, it is possible to further prevent deformation from being transmitted to the communication device, while when the ratio E1/E3 is 2.85 or less, it is possible to prevent the rigidity difference between the first covering rubber 14 and the adjacent tire constituent member from becoming too large, thereby suppressing failures and the like that occur at the interface between them.
Moreover, the ratio E2/E3 is preferably 0.28 or more and 0.71 or less. By making the ratio E2/E3 0.28 or less, deformation occurring in the tire can be further dispersed, while by making the ratio E2/E3 0.71 or more, the rigidity difference between the second covering rubber 15 and the adjacent tire constituent member can be prevented from becoming too large, thereby suppressing failures and the like occurring at the interface therebetween.

When a pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and unloaded, the ratio V2/V1 of the volume V2 of the second covering rubber 15 to the volume V1 of the first covering rubber 14 is
It is preferable that the ratio V2/V1 is 0.26 or more and 0.35 or less. By making the ratio V2/V1 0.26 or more, the deformation occurring in the tire can be further dispersed.
By keeping /V1 at 0.35 or less, it is possible to prevent deformation from being transmitted to the communication device more effectively.

Although not particularly limited, the pneumatic tires disclosed herein are particularly suitable for passenger car tires or truck and bus tires.

1: tire; 2: bead portion; 3: carcass; 4: belt;
5: tread, 6: circumferential main groove, 7: tire inner surface, 8: inner liner,
9: communication device member, 10: communication device, 11: IC chip, 12: antenna,
13: Covering rubber, 14: First covering rubber, 15: Second covering rubber

Claims (7)

A pneumatic tire incorporating a communication device member in which the communication device is rubber-covered,
the communication device member includes a first covering rubber that covers the communication device, and a second covering rubber that covers an outer periphery of the first covering rubber,
The communication device includes one or more antennas for transmitting and/or receiving electromagnetic waves and an IC chip;
The elastic modulus E2 of the second coating rubber is smaller than the elastic modulus E1 of the first coating rubber,
The pneumatic tire according to claim 1, wherein the first covering rubber completely surrounds an entire outer periphery of the communication device . The pneumatic tire according to claim 1, wherein the ratio E1/E2 is 2 or more and 10 or less. The elastic modulus E1 of the first covering rubber is greater than the elastic modulus E3 of the rubber of the tire constituent member adjacent to the communication device member,
3. The pneumatic tire according to claim 1, wherein the elastic modulus E2 of the second covering rubber is smaller than the elastic modulus E3 of the rubber of the tire constituent member adjacent to the communication device member. The pneumatic tire according to claim 3, wherein the ratio E1/E3 is 1.42 or more and 2.85 or less. The pneumatic tire according to claim 3 or 4, wherein the ratio E2/E3 is 0.28 or more and 0.71 or less. The pneumatic tire according to any one of claims 1 to 5, wherein when the pneumatic tire is mounted on an applicable rim, inflated to a specified internal pressure, and unloaded, the ratio V2/V1 of the volume V2 of the second covering rubber to the volume V1 of the first covering rubber is 0.26 or more and 0.35 or less. The pneumatic tire according to any one of claims 1 to 6, wherein the communication device is an RF tag having the antenna and the IC chip having a memory unit.

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