Green tire and tire manufacturing method

Abstract

According to the present invention, a communication device on the surface of a green tire is configured to include an RFID and a coating rubber layer that covers at least the green-tire outer side of the RFID, and further include a reinforcing rubber layer that covers the green-tire outer side of the coating rubber layer. By setting the dielectric constant of the coating rubber layer smaller than the dielectric constant of the reinforcing rubber layer, it is possible to obtain the green tire that is advantageous when subjected to tire manufacturing in which the RFID in the communication device disposed inside the tire is not damaged or exposed to the surface of the tire, while improving the communication performance of the communication device.

Description

Green Tire and Method for Manufacturing a Tire

[0001] The present invention relates to a green tire and a method for manufacturing a tire.

[0002] Tires in which a communication device such as an RFID tag is embedded inside are known. To embed this communication device inside the tire, at the green tire molding stage, after attaching the communication device to a predetermined position in advance, vulcanization molding is performed. For example, Patent Document 1 discloses a method for manufacturing this type of tire and the tire.

[0003] Japanese Patent Application Laid-Open No. 2024-15903

[0004] In the tire described in Patent Document 1, an electronic device is described as the communication device, and such an electronic device is provided with a thin sheet-like or slightly thick patch-like elastic member (rubber) only on at least a part of the surface of the electronic device. Here, in the technique described in Patent Document 1, although the specific performance of such rubber is not particularly described, for example, when using a rubber material that does not cause a decrease in communication performance, the strength, durability, and cut resistance at the location where such rubber is exposed may decrease, or foreign matter may混入 the surface of the tire, resulting in design problems. Further, according to the method for manufacturing the above tire, the communication device is embedded inside the tire, but due to the rubber flow generated during vulcanization molding, there is a risk that the communication device will be damaged (for example, the RFID antenna will break), and it has been desired to reliably avoid this damage.

[0005] The present invention provides a green tire that is advantageous for use in manufacturing a tire in which a communication device attached outside the carcass, which is the skeleton of the tire body, improves its communication performance and in which the RFID in such a communication device is not damaged or exposed on the surface of the tire, together with a method for manufacturing a tire using the green tire.

[0006] (1) A green tire comprising a green tire body and a communication device attached to the surface of the green tire body, wherein the communication device includes an RFID and a covering rubber layer covering at least the outer side of the green tire of the RFID, and further comprises a reinforcing rubber layer covering the outer side of the green tire of the covering rubber layer, wherein the dielectric constant of the covering rubber layer is smaller than that of the reinforcing rubber layer.

[0007] (2) In the raw tire described in (1) above, the thickness of the reinforcing rubber layer is 0.7 mm or more.

[0008] (3) In the raw tire described in (1) or (2) above, the thickness of the reinforcing rubber layer shall be 3.0 mm or less.

[0009] (4) In the raw tire described in any one of the above items (1) to (3), the step difference between the edge of the covering rubber layer and the edge of the reinforcing rubber layer shall be 3.0 mm or less in the distance in the thickness direction of the communication device.

[0010] (5) A method for manufacturing a tire comprising a tire body and a communication device attached to the outside of a carcass that forms the skeleton of the tire body, wherein the green tire described in any one of the above items (1) to (4) is placed in a mold and vulcanized.

[0011] According to the present invention, it is possible to provide a tire in which a communication device installed inside the tire improves its communication performance while preventing damage or exposure to the tire surface.

[0012] This is a schematic cross-sectional view in the tire width direction of a green tire according to one embodiment of the present invention. This figure shows examples of communication devices that may be used in a method for manufacturing a green tire, including a conventional communication device or a communication device of the present invention, where (a) is a schematic plan view showing an example of a conventional communication device, (b) is a schematic perspective view showing another example of a conventional communication device, and (c) is a schematic longitudinal cross-sectional view of a communication device showing an example of a communication device of the present invention. This is a schematic cross-sectional view in the tire width direction showing an example of a mold and a green tire that may be used in a method for manufacturing a tire according to one embodiment of the present invention. This figure illustrates the flow of rubber around a communication device in a conventional vulcanization molding process. This figure illustrates the flow of rubber around a communication device in a vulcanization molding process according to the present invention.

[0013] The green tire and the method for manufacturing a tire using the green tire according to the present invention can be suitably used as a method for manufacturing any type of tire and any type of tire, for example, as a passenger car tire, a truck / bus tire, a construction / mining vehicle tire, etc., or as a method for manufacturing them, and in particular can be suitably used as a method for manufacturing truck / bus tires and construction / mining vehicle tires.

[0014] The following describes embodiments of the green tire and the method for manufacturing a tire using the green tire according to the present invention, with reference to the drawings. Common members and parts in each figure are denoted by the same reference numerals. In this specification, "tire circumferential direction" refers to the direction in which the tire rotates around the tire's axis of rotation, "tire radial direction" refers to the direction perpendicular to the tire's axis of rotation, and "tire width direction" refers to the direction parallel to the tire's axis of rotation. In some drawings, the tire circumferential direction is indicated by the reference numeral "CD", the tire radial direction by the reference numeral "RD", and the tire width direction by the reference numeral "WD".

[0015] In this specification, the side of the tire closer to the axis of rotation along the tire's radial direction is referred to as the "inner side in the tire's radial direction," and the side of the tire further from the axis of rotation along the tire's radial direction is referred to as the "outer side in the tire's radial direction." Furthermore, in this specification, the side of the tire closer to the tire's equatorial plane CL along the tire's width direction is referred to as the "inner side in the tire's width direction," and the side of the tire further from the tire's equatorial plane CL along the tire's width direction is referred to as the "outer side in the tire's width direction." In this specification, "inner tire surface" refers to the surface of the tire facing the inner cavity of the tire, and "outer tire surface" refers to the surface of the tire facing the outside of the tire. In this specification, the terms "tire circumferential direction," etc., and symbols such as "CD" are used not only for vulcanized tires (i.e., finished tires) but also for unvulcanized green tires. Furthermore, in this specification, the terms "mold circumferential direction," etc., and symbols such as "CD" may be used with the same meaning as above for molds used to vulcanize green tires.

[0016] <Raw Tire> First, a raw tire 10 according to one embodiment of the present invention will be described with reference to Figure 1. Figure 1 is a drawing for illustrating a raw tire 10 according to one embodiment of the present invention, and is a schematic cross-sectional view of the raw tire 10 in the tire width direction. Note that the raw tire 10 of the embodiment of the present invention may be configured as a raw tire for any type and / or any size of tire. For example, the raw tire 10 of this embodiment may be configured as a raw tire for a tire in which the nominal rim diameter of the applicable rim is 20 inches or more. Examples of nominal rim diameters of the applicable rim that are 20 inches or more include, for example, 25 inches, 29 inches, 33 inches, 35 inches, 49 inches, 51 inches, 57 inches, 63 inches, etc. Also, when the nominal rim diameter of the applicable rim is 20 inches or more, according to this embodiment, if the communication device is attached to the inner surface side of the tire, problems with communication may occur, for example. Therefore, in the case of such large tires, it is preferable to attach the communication device near the outer surface of the tire side.

[0017] Herein, in this specification, "nominal rim diameter of the applicable rim" (hereinafter also simply referred to as "nominal rim diameter") refers to the inner diameter of the tire and, by extension, the rim diameter of the applicable rim. More specifically, it refers to the nominal rim diameter of the applicable rim (in inches) as indicated in the tire size display on the sidewall of the tire, that is, the rim diameter of the applicable rim expressed in inches. For example, if the tire size is "29.5R25", the nominal rim diameter is "25 inches", if the tire size is "18.00R33", the nominal rim diameter is "33 inches", if the tire size is "46 / 90R57", the nominal rim diameter is "57 inches", and if the tire size is "59 / 80R63", the nominal rim diameter is "63 inches".

[0018] In this specification, "Applicable Rim" refers to the standard rim for the applicable size (Measuring Rim in ETRTO's STANDARDS MANUAL, Design in TRA's YEAR BOOK) which is an industrial standard valid in the region where the tire is produced and used, and which is described or will be described in the future in publications such as the JATMA YEAR BOOK of JATMA (Japan Automobile Tire Manufacturers Association) in Japan, the STANDARDS MANUAL of ETRTO (The European Tyre and Rim Technical Organization) in Europe, and the YEAR BOOK of TRA (The Tire and Rim Association, Inc.) in the United States. This refers to the rim, but in the case of sizes not listed in these industry standards, it refers to a rim with a width corresponding to the bead width of a pneumatic tire. "Applicable rims" include current sizes as well as sizes that will be listed in the aforementioned industry standards in the future. An example of "sizes that will be listed in the future" is the size listed as "FUTURE DEVELOPMENTS" in the ETRTO 2013 edition.

[0019] The green tire 10 according to this embodiment is for a pneumatic tire and, as shown in Figure 1, has a bead portion 1, a sidewall portion 2, and a tread portion 3. The bead portion 1 is the portion configured to contact the rim on the inner side in the radial direction of the tire and on the outer side in the width direction of the tire when the tire is mounted on the rim. The tread portion 3 is the portion of the green tire 10 in the tire width direction between a pair of tread ends. The sidewall portion 2 is the portion between the pair of bead portions 1 and the tread portion 3. In this specification, the sidewall portion 2 and the bead portion 1 of the green tire 10 may be collectively referred to as the tire side portion 8. The sidewall portion 2 refers to the portion that is at least the portion inside the tire radial direction of the belt 5, which will be described later, and the portion that is outside the tire radial direction of the bead portion 1.

[0020] More specifically, the green tire 10 of this embodiment comprises a pair of bead portions 1 having a bead core 11, a carcass 4 consisting of at least one (one in the illustrated example) carcass ply extending in a toroidal shape between the pair of bead portions 1 via a pair of sidewall portions 2 and a tread portion 3, a belt 5 consisting of at least one (six in the illustrated example) belt layer provided on the radially outer side of the carcass 4 (i.e., the crown portion of the carcass 4) in the tread portion 3, and a communication device 6 (synonymous with the communication device laminate 60 described later in the illustrated example) attached to the surface of the tire side portion 8 (more specifically, in this example, the bead portion 1 and the sidewall portion 2). Here, in this specification, "communication device" refers to a device equipped with known electronic components, for example, one that has a communication function with the outside by wireless or other means. In this specification, the part of the green tire 10 excluding the communication device 6 (communication device laminate 60) may be referred to as the "green tire body".

[0021] In this embodiment, each bead core 11 is embedded in the corresponding bead portion 1. The bead core 11 may comprise a plurality of bead wires that are covered with rubber. However, the bead core 11 may consist of a single bead wire. The bead wire is preferably made of metal (e.g., steel). The bead wire may consist of, for example, a monofilament or a stranded wire. The bead wire may also be made of organic fibers or carbon fibers. In this embodiment, as shown in Figure 1, the cross-sectional shape of the bead core 11 in the tire width direction is a regular hexagon, but the cross-sectional shape of the bead core 11 may be other shapes, such as polygonal shapes other than a regular hexagon, circular shapes, etc.

[0022] In this embodiment, as shown in Figure 1, the carcass 4 comprises a carcass body portion located between the bead cores 11 of a pair of bead portions 1, and carcass folded portions that are folded back from both ends of the carcass body portion around each bead core 11 from the inside to the outside in the tire width direction. However, the carcass 4 does not have to have carcass folded portions. Each carcass ply constituting the carcass 4 includes one or more carcass cords and a covering rubber covering the carcass cords. The carcass cords can be formed from, for example, monofilament or stranded wire. In this embodiment, the carcass cords are made of steel. Because the carcass cords are made of steel, sufficient strength can be obtained even if the carcass is made of a simple radial structure in, for example, a large tire. Also, in this embodiment, the carcass 4 has a radial structure. That is, each carcass cord included in the carcass ply of the carcass 4 extends substantially along the tire width direction (i.e., without being inclined at a substantially 0° angle with respect to the tire width direction in a projection view from the tire radially outward of the tread portion 3). However, the carcass cords may be composed of organic fibers such as polyester, nylon, rayon, or aramid. Furthermore, the carcass 4 may have a bias structure.

[0023] In this embodiment, each belt layer constituting the belt 5 includes one or more belt cords and a covering rubber that covers the belt cords. The belt cords can be formed from, for example, monofilaments or stranded wires. The belt cords may be made of metal (e.g., steel) or organic fibers such as polyester, nylon, rayon, or aramid.

[0024] As shown in Figure 1, in this embodiment, the communication device 6 is attached to the outer surface 10a of the green tire on the tire side portion 8. In this embodiment, the communication device 6 includes an RFID and a covering rubber layer 61 that covers at least the outer side of the RFID on the green tire, and further includes a reinforcing rubber layer 62 that covers the outer side of the covering rubber layer on the green tire. Such a communication device 6, i.e., the communication device of the present invention, is installed on the surface of the tire side portion 8 of the green tire 10 as a communication device laminate 60 (see Figure 2(c)). The reason why the communication device 6 has a covering rubber layer 61 and a reinforcing rubber layer 62 on at least a part of the surface of the communication device 6 is that the communication performance of the communication device 6 is improved, the resistance to damage to the device is improved, and the effect of rubber flow on irregularities such as side lettering and vent spews is suppressed, thereby suppressing damage to the electronic device.

[0025] Furthermore, if the communication device laminate 60 is as shown in Figure 2(c), which will be described later, the thin IC chip 6a may be attached to the outer surface 10a of the raw tire such that the surfaces on both sides of the thickness direction TD (for example, the upper and lower surfaces with respect to the plane of the paper in Figure 2(c)) are aligned with the outer surface 10a of the raw tire (i.e., the two are substantially parallel).

[0026] Furthermore, in the illustrated example, the outer side of the belt 5 in the tire radial direction of the tread portion 3 is provided with tread rubber that forms the tread tread surface, which is the outer surface 10a of the raw tire of the tread portion 3. A tread pattern is formed on the tread tread surface during the tire manufacturing process described later. In this embodiment, the tread pattern is a lug pattern in which lugs are partitioned in the circumferential direction of the tire by lug grooves, but the tread pattern is not particularly limited. Furthermore, in the illustrated example, the outer side of the carcass 4 in the tire width direction of the tire side portion 8 is provided with side rubber that forms the outer surface 10a of the raw tire of the tire side portion 8. In addition, the inner surface side of the raw tire 10 in this embodiment may be made of an inner liner (not particularly shown) that is permeable to air and / or gas.

[0027] Figure 2 shows examples of communication devices that may be used in tire manufacturing methods. Figure 2(a) is a schematic plan view of a conventional communication device, Figure 2(b) is a schematic perspective view of another example of a conventional communication device, and Figure 2(c) is a schematic longitudinal cross-sectional view of a communication device showing an example of a communication device according to the present invention.

[0028] As shown in Figure 2(a), the communication device 6 is an RF tag having an IC chip 6a with a memory unit and the like, and one or more (two in the illustrated example) antennas 6b that transmit and / or receive electromagnetic waves. RF tags are also generally called RFID (Radio Frequency Identification) tags. The antennas 6b are connected to the IC chip 6a and extend in a linear, wavy, or spiral shape (spiral in the illustrated example). These two antennas 6b extend from the IC chip 6a in opposite directions. However, the antennas 6b may extend from the IC chip 6a in only one direction. Furthermore, the lengths of the long-side LD of the IC chip 6a described later are the same for the two antennas 6b. However, the lengths of the long-side LD of the IC chip 6a may be different for the two antennas.

[0029] The IC chip 6a is a thin, thin plate with a roughly rectangular shape in plan view (see Figure 2(a)). Here, the "thickness" of the IC chip 6a refers to the thickness in the direction LD parallel to the direction along the long side of the IC chip 6a in plan view (hereinafter also referred to as the "long side direction of the IC chip (6a)"), the direction SD parallel to the direction along the short side of the IC chip 6a in plan view (hereinafter also referred to as the "short side direction of the IC chip (6a)"), and the direction TD perpendicular to both of these directions (hereinafter also referred to as the "thickness direction of the IC chip (6a)"). In this embodiment, the long side direction LD of the IC chip (6a) is also the longitudinal direction of the communication device (6), the short side direction SD of the IC chip (6a) is also the short side direction of the communication device (6), and the thickness direction TD of the IC chip (6a) is also the thickness direction of the communication device (6). The IC chip 6a has, for example, a storage unit which is any known memory and a control unit which is any known processor. The IC chip 6a may operate using induced electromotive force generated by electromagnetic waves received by one or more antennas 6b. That is, the communication device 6 may be a passive communication device. Alternatively, the communication device 6 may further include a battery and be able to communicate by generating electromagnetic waves with its own power. That is, the communication device 6 may be an active communication device. The control unit of the IC chip 6a can, for example, read data such as tire manufacturing management, shipping management, and usage history management stored in the storage unit, or write such data to the storage unit.

[0030] Figure 2(b) shows an example of a communication device laminate 60 having a coating rubber layer 61 on at least a portion of the surface of the communication device 6. That is, such a communication device 6 has a coating 61 on at least a portion of the surface of the communication device 6. As shown in Figure 2(b), the coating rubber layer 61 (one-sided coating rubber layer 61a and the other-sided coating rubber layer 61b) is, for example, a thin sheet of rubber having the properties described later. In other words, the communication device 6 may be formed as a communication device in which the entire surfaces of one side and the other side in the thickness direction TD are covered with a sheet of coating rubber. Note that the configuration of the communication device 6 in the example of Figure 2(b) is the same as the configuration of the communication device 6 in Figure 2(a) described above as the communication device 6.

[0031] Figure 2(c) shows an example of a communication device laminate 60, which is a communication device of the present invention, comprising a reinforcing rubber layer 62 provided on at least the entire surface of one side (outside in the tire width direction) of the coating rubber layer 61 disposed on the surface of the communication device 6 in the thickness direction TD of the communication device 6. In this embodiment, the reinforcing rubber layer 62 can be, for example, a rubber sheet having the properties described later. That is, the reinforcing rubber layer 62 is located on the outside in the tire width direction of the communication device 6 and the coating rubber layer 61, and is responsible for protecting the antenna portion 6b of the communication device 6 in particular. Here, it is important to apply a rubber material with a lower dielectric constant than the reinforcing rubber layer 62 to the coating rubber layer 61, because this improves communication performance. In addition, the reinforcing rubber layer 62 can function sufficiently with just one layer, but it may be composed of two or more layers, as shown in Figure 2(c). Note that the configuration of the communication device 6 in the example of Figure 2(c) is the same as the configuration of the communication device 6 in Figure 2(a) described above as the communication device 6.

[0032] In the examples of Figures 2(b) and 2(c) above, the communication device 6 is provided with a covering rubber layer 61 over its entire surface. However, when the communication device 6 is configured as the communication device laminate 60 of the present invention, the communication device laminate 60 may be provided with a covering rubber layer 61 over at least a portion of its surface. As shown in the example of Figure 2(c), the communication device laminate 60 is provided with a covering rubber layer 61 and a reinforcing rubber layer 62 over at least the entire surface of one side in the thickness direction TD of the communication device laminate 60.

[0033] The communication device laminate 60 according to the present invention can be used in a tire manufacturing method according to one embodiment of the present invention, which will be described later. In this case, the communication device laminate 60 is attached to the surface of the tire side portion 8 of the green tire 10 according to one embodiment of the present invention, which has been described with reference to Figure 1. Although the communication device 6 and the communication device laminate 60 are simplified in Figure 1, in the example of Figure 1, the communication device 6 is attached to the outer surface 10a of the green tire with one side and the other side of the thin plate-shaped IC chip 6a in the thickness direction TD (i.e., so that the two are substantially parallel).

[0034] In the green tire 10 according to one embodiment of the present invention shown in Figure 1, if the communication device laminate 60 is, for example, an RF tag as shown in Figure 2(a) and includes an antenna 6b, the communication device laminate 60 may be attached to the surface of the green tire 10 such that, in a view in the tire rotation axis direction, the antenna 6b extends in a direction intersecting the extending direction of the carcass cord included in the carcass ply of the carcass 4 (preferably in a direction perpendicular to the extending direction). If the carcass 4 has a radial structure, in this case, the entire longitudinal LD ​​of the communication device laminate 60 is suppressed from being greatly bent by the bending strain of the sidewall portion 2, and the durability of the communication device 6 in the communication device laminate 60 can be improved.

[0035] The reinforcing rubber layer 62 used in the present invention is preferably 0.7 mm or thicker. This is because it improves resistance to damage. If the thickness is less than 0.7 mm, there is a possibility that the RF tag may become visible on the surface of the finished tire during internal pressure filling, use, and driving. On the other hand, the reinforcing rubber layer 62 is preferably 3.0 mm or less thick. If the thickness exceeds 3.0 mm, localized protrusions will form on the surface of the green tire, and the formation of localized protrusions will increase the risk of rubber indentation during vulcanization molding.

[0036] Furthermore, when attaching a communication device to the surface of a raw tire, if the size of the covering rubber layer 61 and the reinforcing rubber layer 62 differs, and a step is created between the edge of the covering rubber layer 61 and the edge of the reinforcing rubber layer 62, it is preferable that the distance of this step (represented by T in Figure 2(c)) in the thickness direction of the communication device be 3.0 mm or less. That is, by making this step 3.0 mm or less, the formation of the localized protrusions described above can be suppressed, and the pinching of the rubber during vulcanization molding can be further suppressed. The distance between the ends of the reinforcing rubber layer 61 and the covering rubber layer 62 in a plan view (both in the longitudinal and transverse directions in Figure 2(c)) is preferably 3.0 mm or more, and more preferably 5.0 mm or more considering the work surface.

[0037] <Tire Manufacturing Method> Next, a tire manufacturing method according to one embodiment of the present invention, which is suitable for manufacturing the tire obtained by the present invention, will be described with reference to Figure 3. Figure 3 is a schematic cross-sectional view in the tire width direction showing an example of a mold and a green tire that can be used in the tire manufacturing method according to one embodiment of the present invention for explaining the tire manufacturing method.

[0038] First, a mold that can be used in a tire manufacturing method according to one embodiment of the present invention will be described. In Figure 3, reference numeral 30 denotes a tire vulcanizing apparatus, which can manufacture a tire by vulcanizing an unvulcanized tire, i.e., a green tire 20. The green tire 20, like a tire, comprises a pair of bead portions 21, sidewall portions 22 extending outward in the tire radial direction from each bead portion 21, and a tread portion 15 connecting the radially outer ends of these sidewall portions 22. In this specification, the sidewall portions 22 and bead portions 21 of the green tire 20 may be collectively referred to as the tire side portion 28. Here, in Figure 3, internal members that the green tire 20 has, similar to the green tire 10 in Figure 1, such as the bead core, carcass, belt, etc., are omitted from description to avoid complexity.

[0039] In this embodiment, the tire vulcanizing apparatus 30 has a mold 31, which consists of at least a substantially ring-shaped lower mold 32 and a substantially ring-shaped upper mold 33. The lower mold 32 has a tire side molding surface 323 on its upper surface in a region approximately in the center of the tire in the radial direction, for molding various markings (letters, numbers, and patterns: for example, brand name, product model, tire size, etc.) onto at least a portion of the tire side portion 28 on one side (lower side) of the raw tire 20. Similarly, the upper mold 33 has a tire side molding surface 333 on its lower surface in a region approximately in the center of the tire in the radial direction, for molding (same as above) onto at least a portion of the tire side portion 28 on the other side (upper side) of the raw tire 20.

[0040] In Figure 3, reference numeral 321 and 331 indicate the tread molding surfaces in the mold 31 used to mold the tread portion 23 of the green tire 20, and reference numeral 322 and 332 indicate the lug groove forming bones in the mold 31 used to form lug grooves in one (lower) half and the other (upper) half of the green tire 20, respectively. As shown in Figure 3, the lug groove forming bones 322 and 332 protrude inward in the tire radial direction from the outer end portion in the tire radial direction of the lower mold 32 and the outer end portion in the tire radial direction of the upper mold 33, respectively, and are arranged at, for example, equidistant distances in the tire circumferential direction.

[0041] In this embodiment, the tire vulcanizing apparatus 30 has a shaping unit 34. The shaping unit 34 has a one-side support 35 on which the bead portion 21 on one side (lower side) of the green tire 20 is seated and which can mainly tidy up the bead portion 21, and a other-side support 36 on which the bead portion 21 on the other side (upper side) of the green tire 20 is seated and which can mainly tidy up the bead portion 21. These one-side support 35 and other-side support 36 can be detachably connected by a connecting mechanism (not shown). In Figure 3, reference numeral 80 denotes a flexible bladder provided on the shaping unit 34, with one end and the other end in the tire width direction securely locked to the one-side support 35 and other-side support 36, respectively.

[0042] Here, as shown in Figure 3, the aforementioned communication device 6 (communication device laminate 60) is positioned on the tire side portion 28 of the green tire 20. However, the communication device 6 only needs to be positioned on at least one of the surfaces of the tire side portion 28 that contacts the lower mold 32 of the green tire 20, and the surface of the tire side portion 28 that contacts the upper mold 33 of the green tire 20, before the green tire 20 is housed in the vulcanization space VS, the lower mold 32 and the upper mold 33 are closed to each other, and vulcanization begins.

[0043] The following describes a method for manufacturing a tire according to an embodiment of the present invention, which includes a tire body and a communication device attached to the outside of a carcass that forms the framework of the tire body. The method for manufacturing a tire according to the present embodiment manufactures a green tire 10 using, for example, a tire vulcanizing device 30, and thus, a mold 31, a lower mold 32, an upper mold 33, etc., as described with reference to FIG. 3. That is, the method for manufacturing a tire according to the present embodiment is, for example, a manufacturing method for obtaining a tire in which a communication device laminate 60 according to the present invention is embedded in a tire side portion 8 as described above. As described above, the type and / or size of the green tire 10 may be arbitrary, but the green tire 10 may be configured as a green tire to be used for a tire having a nominal rim diameter of the applicable rim of 20 inches or more, for example.

[0044] In the method for manufacturing a tire according to the present embodiment, the lower mold 32 and the upper mold 33 are used as the mold 31 for vulcanizing the green tire 20. The configurations of the mold 31, the lower mold 32, and the upper mold 33 are not particularly limited as long as the lower mold 32 provided on the lower side in the vertical direction and the upper mold 33 provided on the upper side in the vertical direction from the lower mold 32 are used. However, as the mold 31, the lower mold 32, and the upper mold 33, for example, the mold 31, the lower mold 32, and the upper mold 33 as described above can be used while referring to FIG. 3.

[0045] (Communication device attachment step) Referring to FIG. 3, in the communication device attachment step, it is preferable to dispose the communication device laminate 60 according to the present invention on at least one of the surfaces of the tire side portion 28 on the side contacting the lower mold 32 of the green tire 20 and the surface of the tire side portion 28 on the side contacting the upper mold 33 of the green tire 20. Here, the “tire side portion 28 on the side contacting the lower mold 32 (or the upper mold 33) of the green tire 20” means the tire side portion 28 in the tire half portion of the green tire 20 that contacts the lower mold 32 (or the upper mold 33) in the vulcanization step described later.

[0046] More specifically, in the present embodiment using the tire vulcanizing apparatus 30 shown in FIG. 3, in the communication device arranging step, the communication device laminate 60 is arranged on the lower mold 32 and the upper mold 33 (specifically, the tire side portion molding surface 323 of the lower mold 32 and the tire side portion molding surface 333 of the upper mold 33). However, as described above, in the communication device attaching step, the communication device laminate 60 may be attached to at least one of the surfaces of the tire side portion 28 on the side contacting the lower mold 32 of the green tire 20 and the surfaces of the tire side portion 28 on the side contacting the upper mold 33 of the green tire 20.

[0047] The attachment position of the communication device laminate 60 is such that in a state where the green tire 20 is accommodated in the mold 31 and the mold is closed, the minimum distance between the communication device laminate 60 and the vent holes of the lower mold 32 and the upper mold 33 is more than 0 mm, that is, the communication device laminate 60 and the vent holes of the lower mold 32 and the upper mold 33 are arranged so as not to overlap in the tire width direction. It is preferable to subject the green tire 20 to vulcanization molding. The minimum distance is more preferably 2 mm or more, and even more preferably 5 mm or more.

[0048] That is, in the next vulcanization step, the lower mold 32 and the upper mold 33 are closed, and after setting (accommodating) the green tire 20 with the communication device laminate 60 attached therein in the mold 31, that is, in the vulcanization space VS, a high-temperature and high-pressure vulcanizing medium is supplied into the bladder 80 to vulcanize the green tire 20. In this vulcanization step, various displays are transferred and engraved on the tire side portion 28 of the green tire 20, and various displays due to unevenness are formed on the tire side portion 28 of the vulcanized tire, that is, the manufactured tire.

[0049] In this vulcanization step, in order to surely mold the tire, it is common practice to provide a large number of vent holes in the lower mold 32 and the upper mold 33 to discharge the gas generated in the rubber during the vulcanization process from the vent holes to the outside of the mold. In particular, it is common practice to provide concave portions and vent holes in the mold region for transferring the convex portions for the above various displays.

[0050] Here, Figure 4(a) schematically shows a state in which a conventional communication device 6 is attached and set on the tire side portion 28 of a green tire 20 in a mold region where the recess 70 and vent hole 71 are provided as shown. As vulcanization progresses in this set state, as shown in Figure 4(b), a phenomenon occurs in which the rubber around the communication device 6 (including the rubber for the coating rubber layer 61) flows toward the recess 70 and vent hole 71. This rubber flow partially moves the IC chip 6a and antenna 6b of the communication device 6, resulting in bending occurring at the connection between the IC chip 6a and the antenna 6b and within the antenna 6b. In particular, since the connection between the IC chip 6a and the antenna 6b is relatively fragile, the connection may break, hindering the communication function of the communication device 6.

[0051] Therefore, in the present invention, the minimum distance between the communication device laminate 60 according to the present invention and the vent holes 71 of the lower mold 32 and upper mold 33 is set to more than 0 mm, that is, the communication device laminate 60 and the vent holes 71 of the lower mold 32 and upper mold 33 are arranged so that they do not overlap in the tire width direction, thereby avoiding the situation in which rubber flow occurs as shown in Figure 4.

[0052] Furthermore, in this invention, since the reinforcing rubber layer 62 prevents (suppresses) rubber flow, it is possible to prevent bending from occurring at the connection between the IC chip 6a and the antenna 6b, or within the antenna 6b, as shown in Figure 5.

[0053] The minimum distance mentioned above refers to the minimum distance between the communication device laminate 60 and the vent hole 71 when the raw tire 20 is housed in the vulcanization space VS within the lower mold 32 and upper mold 33, the lower mold 32 and upper mold 33 are closed, and the raw tire 20 with the communication device laminate 60 attached is set (stored) in the vulcanization space VS within the mold 31.

[0054] (Vulcanization Process) Referring to Figure 3, in the vulcanization process, after the communication device placement process described above, the green tire 20 is set in the mold 31 and vulcanized. More specifically, in the example using the tire vulcanization apparatus 30 shown in Figure 3, in the vulcanization process, for example, after both bead portions 21 of the unvulcanized green tire 20 are seated on the one-side support 35 and the other-side support 36 respectively, these one-side support 35 and the other-side support 36 are connected by a connecting mechanism (not shown), and then when internal pressure is filled into the bladder 80, the green tire 20 deforms into a roughly toroidal shape and is supported by the shaping unit 34 consisting of these one-side support 35, the other-side support 36 and the bladder 80. Next, the green tire 20 mounted on the shaping unit 34 in this manner is transported into the upper mold 33 in an open state by a transport means (not shown), and then placed on the lower mold 32 while aligning the lug groove forming bones 322 of the lower mold 32 with the lug groove forming grooves formed on one side (lower side) of the green tire 20. After that, the lower mold 32 and the upper mold 33 are closed to set (store) the green tire 20 inside the mold 31, i.e., inside the vulcanization space VS, and then a high-temperature, high-pressure vulcanizing medium is supplied into the bladder 80 to vulcanize the green tire 20.

[0055] Furthermore, in the vulcanization process described above, the communication device laminate 60 attached to the green tire 20 is integrally molded with the green tire body, and after vulcanization, i.e., in the manufactured tire, the communication device laminate 60 is embedded in the tire. In this vulcanization process, the flow of rubber around the communication device laminate 60 is reliably suppressed, so that the manufactured tire has an undamaged communication device laminate 60.

[0056] Furthermore, in the present invention, the communication device laminate 60 is provided with a covering rubber layer 61 (one-sided covering rubber layer 61a and / or the other-sided covering rubber layer 61b) on at least a portion of the surface of the communication device laminate 60. In other words, such a communication device laminate 60 includes a communication device 6 including the covering rubber layer 61, as shown in Figure 2(c). By adopting this configuration, it becomes possible to interpose the covering rubber layer 61 between the communication device 6 and the lower mold 32, and between the upper mold 33 and the green tire 20 during the vulcanization process.

[0057] In addition, in the present invention, the communication device laminate 60 further comprises a reinforcing rubber layer 62 provided on at least the entire surface of one side (outer side in the tire width direction) of the coating rubber layer 61 in the thickness direction TD of the communication device 6, as shown in Figure 2(c). By adopting this structure, it becomes possible to more reliably suppress the flow of rubber around the communication device laminate 60 into recesses for side lettering and vent holes in the mold during the vulcanization process, and as described in Figure 5, damage to the communication device 6 during vulcanization molding can be more reliably avoided. Consequently, the damage resistance of the communication device laminate 60 in the tire after vulcanization can be improved.

[0058] Here, the coating rubber layer 61 is preferably made of a rubber material that does not contain carbon black, or a rubber material with a lower carbon black content than the reinforcing rubber. However, it is not particularly limited to any rubber material with a lower dielectric constant than the reinforcing rubber, and any such material can be suitably used. Furthermore, the reinforcing rubber layer 62 may be made of the same rubber material as the side rubber, but it is not particularly limited to any rubber material that satisfies the relationship with the rubber material of the coating rubber layer described above, and any such material can be suitably used. Most importantly in this invention, the dielectric constant of the coating rubber layer is smaller than that of the reinforcing rubber layer. This is because it contributes to improving the communication performance of the communication device (communication device laminate 60) according to this invention.

[0059] In addition, during the communication device mounting process, the communication device laminate 60 may be placed on the green tire 20 via adhesive instead of being placed on the lower mold 32 and upper mold 33 as described above. In this case, for example, during the subsequent vulcanization process, it is possible to prevent the communication device laminate 60 from shifting or falling off the green tire 20.

[0060] Furthermore, in the communication device installation process, it is preferable that the communication device laminate 60 be placed on both sides of the tire side portion 28 of the green tire 20. In this case, in the manufactured tire, the communication device laminate 60 will be attached to both the green tire outer surface 10a of the tire side portion 8 on one half of the tire and the green tire outer surface 10a of the tire side portion 8 on the other half of the tire, with the tire equatorial plane CL as the boundary. As a result, information stored in the communication device laminate 60 can be read from both sides of the tire width direction, ensuring the communication of the communication device laminate 60 even for large tires, regardless of the direction in which the tire is mounted on the vehicle. In addition, even if one side of the communication device laminate 60 malfunctions and becomes non-functional, information can be read from the other side of the communication device laminate 60. However, in the communication device installation process, the communication device laminate 60 may be placed on only one side of the tire side portion 28 of the green tire 20.

[0061] Furthermore, the communication device stacks 60 may be installed at multiple positions spaced apart in the circumferential direction on each tire side portion 28 of the raw tire 20, thereby arranging three or more communication device stacks 60. In this case, even if at least one of the three or more communication device stacks 60 fails or detaches in the manufactured tire, there is a higher probability that one of the other communication device stacks 60 will remain functional. Therefore, for example, it is possible to prevent the inability to read and write tire information using the communication device stacks 60.

[0062] In the above case, it is preferable that the communication device laminate 60 be arranged at equal intervals in the circumferential direction of each tire side portion 28 of the raw tire 20. This arrangement makes it possible to further ensure that at least one of the communication device laminates 60 remains functional by mitigating the effects of events that cause failure or delamination during tire operation in the manufactured tire.

[0063] The green tire and tire manufacturing method according to the present invention can be suitably used as a method for manufacturing any type of tire and any type of tire using such green tire, for example, passenger car tires, truck and bus tires, construction and mining vehicle tires, etc., or as a method for manufacturing them, and in particular can be suitably used as a construction and mining vehicle tire or as a method for manufacturing the same.

[0064] 10, 20: Green tire, 10a: Green tire outer surface, 1, 21: Bead section, 11: Bead core, 2, 22: Sidewall section, 3, 23: Tread section, 4: Carcass, 5: Belt, 6: Communication device, 6a: IC chip, 6b: Antenna, 60: Communication device laminate, 61: Coating rubber layer, 61a: One-sided coating rubber layer, 61b: Other-sided coating rubber layer, 62: Reinforcement rubber layer, 70: Recess, 71: Vent hole, 8, 28: Tire side section, 30: Tire vulcanization device, 31: Mold, 32: Lower mold, 33: Upper mold, 321, 331: Tread section molding surface, 322, 332: Lug groove forming frame, 323, 333: Tire side section molding surface, 34: Shaping unit, 35: One-sided support, 36: Other-sided support, 70: recess, 71: vent hole, 80: bladder, WD: tire width direction, RD: tire diameter direction, CD: tire circumference direction, CL: tire equatorial plane, LD: long side direction, SD: short side direction, TD: thickness direction, VS: vulcanization space

Claims

1. A green tire comprising a green tire body and a communication device attached to the surface of the green tire body, wherein the communication device includes an RFID and a covering rubber layer covering at least the outer side of the green tire of the RFID, and further comprises a reinforcing rubber layer covering the outer side of the green tire of the covering rubber layer, wherein the dielectric constant of the covering rubber layer is smaller than that of the reinforcing rubber layer.

2. The raw tire according to claim 1, wherein the thickness of the reinforcing rubber layer is 0.7 mm or more.

3. The green tire according to claim 1 or 2, wherein the thickness of the reinforcing rubber layer is 3.0 mm or less.

4. The raw tire according to claim 1 or 2, wherein the difference in height between the edge of the covering rubber layer and the edge of the reinforcing rubber layer is 3.0 mm or less in the thickness direction of the communication device.

5. A method for manufacturing a tire, comprising a tire body and a communication device attached to the outside of the carcass which forms the skeleton of the tire body, wherein the green tire described in claim 1 is placed in a mold and vulcanized.

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