pneumatic tires

Abstract

To provide a pneumatic tire which can improve durability of a protrusion to indicate a position of a communication device.SOLUTION: A pneumatic tire according to the present invention comprises: a tire body with a tire side part where an external surface is constituted by a side coating rubber; and a communication device which is buried in the tire side part of the tire body. When a region of the tire side part where the communication device is positioned in a tire radial direction and in a tire circumferential direction is regarded as a device region, the external surface of the tire side part is protruded at the device region, and the thickness of the side coating rubber is thinner at the device region than the periphery of the device region.SELECTED DRAWING: Figure 8

Description

Technical Field

[0001] The present invention relates to pneumatic tires.

Background Art

[0002] Pneumatic tires with a communication device such as an RF tag embedded inside are known. Patent Document 1 discloses this type of pneumatic tire.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is difficult to identify the position of a communication device embedded inside a tire body from the outside of a pneumatic tire. Therefore, in some cases, a protrusion as a display unit for displaying the position of the communication device is provided as in the pneumatic tire described in Patent Document 1. However, the protrusion as the display unit may be damaged or worn due to various impacts from the outside of the pneumatic tire.

[0005] An object of the present invention is to provide a pneumatic tire capable of improving the durability of a protruding portion for displaying the position of a communication device.

Means for Solving the Problems

[0006] A pneumatic tire according to a first aspect of the present invention includes (1) a tire body including a tire side portion whose outer surface is formed of side covering rubber, and a communication device embedded in the tire side portion of the tire body. When the area in the tire radial direction and tire circumferential direction of the tire side portion where the communication device is located is defined as the device area, The outer surface of the tire side portion protrudes in the device area. The thickness of the side covering rubber is thinner in the device area than the surrounding area, and this is a pneumatic tire.

[0007] One embodiment of the present invention is a pneumatic tire, (2) The pneumatic tire described in (1) above has a maximum protrusion of 0.1 to 1.0 mm from the outer surface of the tire side portion in the device area.

[0008] One embodiment of the present invention is a pneumatic tire, (3) On the outer surface of the tire side portion, at least one side in the tire radial direction relative to the device area is provided with a marking portion consisting of a protruding portion. The pneumatic tire described in (2) above, wherein the maximum protrusion amount of the outer surface of the tire side portion in the device area is smaller than the maximum protrusion amount of the protrusion portion constituting the mark portion. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a pneumatic tire that can improve the durability of a protruding portion used to indicate the position of a communication device. [Brief explanation of the drawing]

[0010] [Figure 1] This is a cross-sectional view in the tire width direction of a pneumatic tire as one embodiment of the present invention. [Figure 2] This is a plan view of the communication device. [Figure 3] This is a perspective view of a communication device. [Figure 4] This is a perspective view of the communication device with the outer casing cover removed. [Figure 5] This is a disassembled perspective view of a communication device. [Figure 6] It is a plan view of the second antenna. [Figure 7] It is a partial cross-sectional view of the communication device. [Figure 8] It is a view showing an enlarged view of the vicinity of the communication device in FIG. 1. [Figure 9] It is a view showing an enlarged view of the vicinity of the communication device in the side view of the pneumatic tire shown in FIG. 1. [Figure 10] It is a cross-sectional view of the tire side portion at the position of line II-II in FIG. 9. [Figure 11] It is a view showing a modified example of the arrangement position of the communication device shown in FIG. 1. [Embodiments for Carrying Out the Invention]

[0011] Hereinafter, embodiments of the pneumatic tire according to the present invention will be exemplified and described with reference to the drawings. The same reference numerals are given to the same configurations in each figure.

[0012] FIG. 1 is a cross-sectional view in the tire width direction of a pneumatic tire 50 as an embodiment of the pneumatic tire according to the present invention. As shown in FIG. 1, the pneumatic tire 50 includes a tire body 60 and a communication device 10. Hereinafter, for convenience of explanation, the pneumatic tire 50 will be simply referred to as "tire 50".

[0013] FIG. 1 shows only one half in the tire width direction C with the tire equatorial plane CL of the tire 50 as a boundary, but the other half has the same configuration except for the presence or absence of the communication device 10. However, the tire 50 may have an asymmetric portion with the tire equatorial plane CL as a boundary.

[0014] The tire 50 shown in FIG. 1 is a tire for trucks and buses, but it may also be other heavy-duty tires or passenger car tires.

[0015] [Tire Body 60] The internal structure of the tire body 60 is not particularly limited, but the following configuration can be used as an example. The tire body 60 comprises a pair of tire side portions 57 and a tread portion 53 connected to the pair of tire side portions 57. The pair of tire side portions 57 consist of a pair of bead portions 51 and a pair of sidewall portions 52 connected to the bead portions 51.

[0016] A bead core 51a is embedded in the bead portion 51, and a stiffener 51b is positioned on the outer side of the bead core 51a in the tire radial direction E. In this embodiment, multiple stiffeners 51b1 and 51b2 with different hardnesses (two in this embodiment) are provided as stiffeners 51b. Stiffener 51b1, located on the inner side in the tire radial direction E, is harder than stiffener 51b2, located on the outer side in the tire radial direction E.

[0017] Furthermore, the tire body 60 includes a carcass 54 consisting of one or more carcass plies that toroidally straddle the pair of bead portions 51. The carcass 54 is wrapped around the bead core 51a and folded back from the inside to the outside in the tire width direction C, and extends to the folded end 54a. The carcass plies may be made of radially arranged carcass cords covered with rubber. In this example, the carcass cords are made of steel cords. The number of carcass plies is not particularly limited. The diameter of the carcass cords is not particularly limited, but may be, for example, 0.8 to 1.2 mm.

[0018] A belt 55 consisting of one or more (four in the illustrated example) belt plies 55a to 55d is arranged on the outer side of the crown portion of the carcass 54 in the tire radial direction E. Tread rubber 53a is arranged on the outer side of the belt 55 in the tire radial direction E. In this example, the belt cords of the belt 55 are steel cords. The belt cords can be inclined at an angle of inclination of, for example, 30 to 60° with respect to the tire circumferential direction F. The number of belt layers and the belt width are not particularly limited. Also, as shown in Figure 1, cushion rubber 53b may be arranged near the end of the belt 55.

[0019] In addition to the bead core 51a and stiffener 51b described above, the bead portion 51 is provided with a rubber chafer 51c, a nylon chafer 51d, a wire chafer 51e, and a hat rubber 51f. Furthermore, a side rubber 52a is positioned on the outer side of the carcass 54 in the tire width direction C, extending from the bead portion 51 to the sidewall portion 52.

[0020] The outer surface of the tire body 60 in this embodiment consists of the outer surfaces of a pair of tire side portions 57 and the outer surface of the tread portion 53. The outer surface of the tire side portion 57 is made of side covering rubber 57a. The outer surface of the tread portion 53 is made of tread rubber 53a.

[0021] In this embodiment, the side covering rubber 57a is composed of a rubber chafer 51c in the bead portion 51, and a side rubber 52a that extends across the bead portion 51 and the sidewall portion 52.

[0022] Furthermore, the inner surface of the tire body 60 in this embodiment faces the tire cavity 60a and is composed of an inner liner 56 that extends over the bead portion 51, the sidewall portion 52, and the tread portion 53.

[0023] [Communication device 10] The communication device 10 is embedded in the tire side portion 57 of the tire body 60. Specifically, in this embodiment, the communication device 10 is positioned adjacent to the inside of the side covering rubber 57a in the tire width direction C in the tire side portion 57. More specifically, in this embodiment, the communication device 10 is embedded in the tire side portion 57 at a position adjacent to the inside of the side rubber 52a, which is the side covering rubber 57a, in the tire width direction C, and at a position between the side rubber 52a and the stiffener 51b2.

[0024] The communication device 10 only needs to be configured to be able to communicate wirelessly with a predetermined device outside the tire body 60, and the configuration of the communication device 10 is not particularly limited. An example of the communication device 10 is an RF tag. In this embodiment, the communication device 10 is an RF tag. The RF tag as the communication device 10 is able to communicate wirelessly with a reader located outside the tire body 60. The RF tag may be a passive type RF tag that operates on power supplied from a reader located outside the tire body 60. Specifically, the RF tag as the communication device 10 can receive information transmitted from the reader's antenna on radio waves or a magnetic field using the RF tag's antenna. Power is generated in the RF tag's antenna by rectification (in the case of radio waves) or resonance (in the case of a magnetic field), and the IC chip including the RF tag's memory unit, control unit, etc., performs a predetermined operation. In the RF tag's IC chip, the control unit can read information from a memory unit such as a non-volatile memory and send it back (transmit) to the reader from the antenna on radio waves or a magnetic field. The reader's antenna receives radio waves or a magnetic field from the RF tag. The reader's control unit can retrieve the information stored in the memory section of the RF tag's IC chip by extracting the received information.

[0025] Figure 2 is a plan view of the communication device 10 of this embodiment. Figure 3 is a perspective view of the communication device 10. Figure 4 is a perspective view of the communication device 10 with the cover 32 of the outer casing 3 removed. Figure 5 is an exploded perspective view of the communication device 10. Figure 6 is a plan view of the second antenna 2. Figure 7 is a partial cross-sectional view of the communication device 10. Figure 7 is a cross-sectional view of section II in Figure 3.

[0026] As shown in Figures 2 and 3, the communication device 10 comprises a circuit board 1, a second antenna 2, and an outer casing 3. For the sake of explanation, the longitudinal direction (left-right direction in Figure 2) of the retaining surface 31a of the outer casing 3 (see Figure 4) is referred to as the X direction. One direction of the X direction (right direction in Figure 2) is referred to as the +X direction. The other direction of the X direction (left direction in Figure 2) is referred to as the -X direction. The short direction of the retaining surface 31a of the outer casing 3 (see Figure 4) is referred to as the Y direction. The Y direction is perpendicular to the X direction in the plane along the retaining surface 31a. One direction of the Y direction (up direction in Figure 2) is referred to as the +Y direction. The other direction of the Y direction (down direction in Figure 2) is referred to as the -Y direction. The direction perpendicular to the retaining surface 31a of the outer casing 3 is referred to as the Z direction. The Z direction is perpendicular to the X and Y directions. Viewing from the Z direction is called a plan view (see Figure 2). The Z axis is the central axis along the Z direction.

[0027] As shown in Figure 4, the substrate 1 comprises an IC chip 11, a first antenna 12, and a base material 13.

[0028] The base material 13 is formed in a plate shape. The shape of the base material 13 in plan view is not particularly limited, but it is preferable that at least a part of the outer edge 13a is curved. Examples of curved shapes include elliptical arcs, circular arcs, and higher-order curves (e.g., quadratic curves). Examples of higher-order curves include parabolic and hyperbolic shapes. The outer shape of the base material 13 in plan view may be, for example, elliptical, circular, or oblong (racetrack shape). A non-circular outer shape of the base material 13 in plan view is preferable. In this embodiment, the base material 13 is elliptical. The base material 13 is positioned with its major axis oriented in the X direction. As the base material 13, glass epoxy resin substrates, ceramics, plastic films, etc., can be used.

[0029] The IC chip 11 allows for contactless writing and reading of information via the first antenna 12 and the second antenna 2. The IC chip 11 is mounted on the substrate 13.

[0030] The first antenna 12 is, for example, a conductive layer formed on one surface of the substrate 13. The conductive layer is composed of, for example, a conductive foil, a plating layer, a conductive ink layer, etc. The conductive foil is a metal foil composed of, for example, copper, silver, gold, platinum, aluminum, etc. The conductive foil is formed into a predetermined shape by etching or the like. The plating layer is composed of, for example, a metal such as copper, silver, gold, platinum, or aluminum. The conductive ink layer is formed by printing or the like using conductive ink. The conductive ink contains conductive particles made of metal, carbon material, etc.

[0031] The first antenna 12 is formed in a loop shape. The first antenna 12 has a curved shape that follows, for example, the outer edge 13a of the base material 13. The first antenna 12 is formed in an elliptical loop shape. The first antenna 12 is electrically connected to the IC chip 11.

[0032] The second antenna 2 is an antenna for the booster. The second antenna 2 is, for example, a linear body. The second antenna 2 is made of a metal such as steel, stainless steel, copper, or a copper alloy. The second antenna 2 can be made of, for example, brass-plated steel wire. The second antenna 2 is separate from the substrate 1. The second antenna 2 in this embodiment has a flattened outer shape. In other words, the flattened second antenna 2 extends in a direction perpendicular to the thickness direction A (Z direction in this embodiment) (in-plane direction of the XY plane in this embodiment). Hereinafter, the direction perpendicular to the thickness direction A (Z direction in this embodiment) (in-plane direction of the XY plane in this embodiment) may simply be referred to as "antenna in-plane direction B". The second antenna 2 in this embodiment is a flattened linear antenna consisting of a linear body extending in the antenna in-plane direction B, but is not limited to this configuration. The second antenna 2 may be, for example, a flattened plate antenna consisting of a plate-like body extending in the antenna in-plane direction B.

[0033] The second antenna 2 comprises an electromagnetic field coupling section 21 and a pair of extension sections 22. The electromagnetic field coupling section 21 has a curved shape. A "curved shape" is a shape that bends smoothly without any sharp bends. Examples of curved shapes include elliptical arcs, circular arcs, and higher-order curves (e.g., quadratic curves). Examples of "higher-order curves" include parabolic and hyperbolic shapes. The electromagnetic field coupling section 21 is semi-elliptical. More specifically, the electromagnetic field coupling section 21 is semi-elliptical, extending from one vertex of an ellipse (the vertex intersecting the major axis) to the other vertex (the vertex intersecting the major axis).

[0034] The electromagnetic field coupling portion 21 has a shape that surrounds at least a part of the substrate 1 in a plan view. The electromagnetic field coupling portion 21 surrounds the range (half-circumference on the +Y direction side) from one vertex (the vertex intersecting the major axis) to the other vertex (the vertex intersecting the major axis) of the elliptical substrate 1.

[0035] The electromagnetic field coupling portion 21 has a curved shape (for example, an elliptical arc) that follows the outer edge 12a of the first antenna 12 in a plan view. The distance between the electromagnetic field coupling portion 21 and the outer edge 12a is approximately constant. The electromagnetic field coupling portion 21 is located outside the outer edge 13a of the substrate 1, and close to the outer edge 13a, in a plan view. The electromagnetic field coupling portion 21 has a shape that follows the outer edge 13a in a plan view. The distance between the electromagnetic field coupling portion 21 and the outer edge 13a is approximately constant.

[0036] The electromagnetic field coupling unit 21 is non-contactively electromagnetically coupled to the first antenna 12. Electromagnetic field coupling refers to, for example, either electric field coupling or magnetic field coupling. The cross-sectional shape of the electromagnetic field coupling unit 21 perpendicular to its length is, for example, circular (see Figure 7).

[0037] The pair of extensions 22 extend from one end 21a of the electromagnetic field coupling portion 21, respectively. As shown in Figure 6, the first extension 22A, one of the pair of extensions 22, extends in the -X direction from the -X end 21a of the electromagnetic field coupling portion 21, meandering along the -X direction. The second extension 22B, the other of the pair of extensions 22, extends in the +X direction from the +X end 21a of the electromagnetic field coupling portion 21, meandering along the +X direction.

[0038] The plan view shape of the extension portion 22 is, for example, a meandering shape, a wavy shape, a zigzag shape, etc. The extension portion 22 has a meandering shape.

[0039] As shown in Figure 5, the extension 22 comprises a plurality of straight sections 23 and a plurality of folded sections 24. The straight sections 23 are straight lines along the Y direction. The plurality of straight sections 23 are spaced apart in the X direction. The folded sections 24 connect the ends of adjacent straight sections 23. The folded sections 24 have a curved shape (for example, an arc shape).

[0040] Of the multiple straight sections 23, the straight section 23 closest to the electromagnetic field coupling section 21 is called the "first straight section 23A". Of the multiple straight sections 23, the straight section 23 second closest to the electromagnetic field coupling section 21 is called the "second straight section 23B". Of the multiple straight sections 23, the straight section 23 third closest to the electromagnetic field coupling section 21 is called the "third straight section 23C". The folded section 24 connecting the first straight section 23A and the second straight section 23B is called the "first folded section 24A". The folded section 24 connecting the second straight section 23B and the third straight section 23C is called the "second folded section 24B".

[0041] The first straight section 23A extends in the -Y direction from the end 21a of the electromagnetic field coupling section 21. The first folded section 24A curves and extends from the -Y end of the first straight section 23A to reach the -Y end of the second straight section 23B. Of the extended section 22, the first straight section 23A and a portion of the first folded section 24A are inside the outer casing 3, but the rest of the extended section 22 extends outside the outer casing 3 (see Figure 4).

[0042] The outer casing 3 holds the substrate 1 and the second antenna 2 on the holding surface 31a.

[0043] More specifically, as shown in Figure 3, the exterior body 3 of this embodiment comprises a plate-shaped main body 31 and a plate-shaped lid 32. One side of the main body 31 in the thickness direction is the holding surface 31a. In the communication device 10 of this embodiment, with the substrate 1 and the second antenna 2 held on the holding surface 31a of the main body 31, the lid 32 is attached so as to cover the holding surface 31a of the main body 31. As a result, the entire substrate 1 and a part of the second antenna 2 (in this embodiment, the entire electromagnetic field coupling part 21 and a part of the pair of extension parts 22) are housed between the holding surface 31a of the main body 31 and the lid 32.

[0044] The outer casing 3 is plate-shaped overall. The main body 31 and the lid 32 are formed of, for example, resin. Examples of resins include polyamide resins such as nylon 6,6; polyester resins such as polyethylene terephthalate (PET); polyolefin resins such as polyethylene; polyfluoroethylene resins such as polyvinyl fluoride; vinyl polymers such as polyvinyl chloride; and acrylic resins such as polymethyl methacrylate.

[0045] As shown in Figure 5, the main body portion 31 is rectangular in plan view. One side of the main body portion 31, the retaining surface 31a, has a substrate retaining recess 37 (substrate retaining portion), an antenna retaining groove 34, and a pair of side recesses 35. The substrate retaining recess 37 is formed by the substrate retaining protrusions 33. The substrate retaining recess 37 is a recess surrounded by the substrate retaining protrusions 33.

[0046] The substrate holding projection 33 is an annular rib-shaped projection. The substrate holding projection 33 has a curved shape (for example, an elliptical shape) that follows the outer edge 13a of the substrate 1. The substrate holding projection 33 protrudes from the holding surface 31a in the +Z direction. The shape of the cross section of the substrate holding projection 33 perpendicular to the longitudinal direction is, for example, rectangular. In a plan view, the substrate holding projection 33 has a curved shape (for example, an elliptical shape) that follows the outer edge 12a of the first antenna 12.

[0047] The substrate holding recess 37 holds the substrate 1. The substrate holding recess 37 is shaped to follow the outer edge 13a of the substrate 1 (for example, elliptical). The internal dimensions (inner diameter) of the substrate holding recess 37 are approximately the same as, or slightly larger than, the external dimensions (outer diameter) of the substrate 1. In plan view, the substrate holding recess 37 is similar in shape to the substrate 1.

[0048] If the substrate 1 and the substrate holding recess 37 are non-circular (for example, elliptical), it is possible to restrict the substrate 1 from tilting around the Z-axis and maintain the correct orientation of the substrate 1. Therefore, the electromagnetic field coupling between the first antenna 12 and the electromagnetic field coupling unit 21 can be maintained.

[0049] The antenna retaining groove 34 accommodates the electromagnetic field coupling portion 21 of the second antenna 2 (see Figures 4 and 7). The antenna retaining groove 34 is formed on the outside of the substrate retaining projection 33, and in close proximity to the substrate retaining projection 33. In a plan view, the antenna retaining groove 34 has a shape that follows the substrate retaining projection 33. In a plan view, the antenna retaining groove 34 has a curved shape (for example, an elliptical arc) that follows the outer edge 12a of the first antenna 12. In a plan view, the antenna retaining groove 34 has a curved shape (for example, an elliptical arc) that follows the outer edge 13a of the substrate 1. In a plan view, the antenna retaining groove 34 has a semi-elliptical shape. More specifically, the antenna retaining groove 34 has a semi-elliptical shape extending from one vertex of the ellipse (the vertex intersecting the major axis) to the other vertex (the vertex intersecting the major axis).

[0050] The antenna retaining groove 34 is shaped to surround at least a portion of the substrate 1 in a plan view. The antenna retaining groove 34 surrounds the area (half-circumference on the +Y direction side) from one vertex (the vertex intersecting the major axis) to the other vertex (the vertex intersecting the major axis) of the elliptical substrate 1.

[0051] As shown in Figure 7, the cross-section of the antenna retaining groove 34 perpendicular to the longitudinal direction is, for example, rectangular. The width (internal dimension) W1 of the antenna retaining groove 34 is greater than the outer diameter (external dimension) D1 of the electromagnetic field coupling part 21. The difference between the width W1 and the outer diameter D1 can be, for example, 0.01 mm to 1 mm (preferably 0.05 mm to 0.2 mm). Because the width W1 of the antenna retaining groove 34 is greater than the outer diameter D1 of the electromagnetic field coupling part 21, the electromagnetic field coupling part 21 is housed in the antenna retaining groove 34 in a state where it can be displaced in the radial direction (for example, the Y direction). The "radial direction" is the direction perpendicular to the longitudinal direction of the electromagnetic field coupling part 21. The electromagnetic field coupling part 21 is also displaceable in the longitudinal direction relative to the antenna retaining groove 34.

[0052] The depth of the antenna retaining groove 34 is determined such that the height (internal dimension) H1 from the bottom surface 34a of the antenna retaining groove 34 to the lid portion 32 (top surface 38a) is greater than the outer diameter D1 of the electromagnetic field coupling portion 21. The difference between the height H1 and the outer diameter D1 can be, for example, 0.01 mm to 1 mm (preferably 0.05 mm to 0.2 mm). Because the height H1 of the antenna retaining groove 34 is greater than the outer diameter D1 of the electromagnetic field coupling portion 21, the electromagnetic field coupling portion 21 is housed in the antenna retaining groove 34 in a state that allows it to be displaced in the radial direction (for example, the Z direction).

[0053] As shown in Figure 5, the side recesses 35 are formed on one and the other side of the retaining surface 31a. The side recesses 35 are formed in the region including the side edge 31b of the main body 31 in the X direction. The inner peripheral edge 35a of the side recess 35 has a first straight portion 35b along the Y direction, a curved portion 35c, and a second straight portion 35d along the X direction.

[0054] The first straight section 35b is the portion that extends in the -Y direction, starting from the end of the inner peripheral edge of the antenna holding groove 34. The curved section 35c is the portion that extends from the tip of the first straight section 35b, with the angle of inclination with respect to the X direction decreasing. The second straight section 35d is the portion that extends from the tip of the curved section 35c along the X direction toward the side edge 31b.

[0055] As shown in Figure 4, the side recess 35, in a plan view, encompasses the first straight section 23A and a portion of the first folded section 24A of the second antenna 2. The first straight section 23A is close to the first straight section 35b (see Figure 5). The first folded section 24A is close to the curved section 35c (see Figure 5). The side recess 35 accommodates at least a portion of a predetermined length range of the second antenna 2 (the first straight section 23A and a portion of the first folded section 24A).

[0056] As shown in Figure 3, since the side recess 35 has sufficient distance in the Y direction, a slit-shaped side end opening 36 extending in the Y direction (along the retaining surface 31a) is formed on the side end edge 31b. The second antenna 2 extends outside the outer casing 3 through the side end opening 36. As shown in Figure 5, two locking recesses 39 are formed on the +Y direction edge 31c of the main body 31, at different positions in the X direction. Two locking recesses 39 are also formed on the -Y direction edge 31d of the main body 31, at different positions in the X direction.

[0057] As shown in Figure 3, the lid portion 32 is rectangular in plan view. The lid portion 32 is the same shape as the main body portion 31 and is installed facing the retaining surface 31a of the main body portion 31. In plan view, the lid portion 32 is installed so as to overlap the retaining surface 31a of the main body portion 31.

[0058] As shown in Figure 7, the opposing surface 32a of the lid portion 32 is the surface that faces the holding surface 31a of the main body portion 31. A positioning groove 38 is formed on the opposing surface 32a. The positioning groove 38 is an annular groove. The shape of the cross section perpendicular to the longitudinal direction of the positioning groove 38 is, for example, rectangular.

[0059] The positioning groove 38 has a curved shape (for example, an elliptical shape) corresponding to the substrate holding protrusion 33 and the antenna holding groove 34. In a plan view, the positioning groove 38 has a width that encompasses both the substrate holding protrusion 33 and the antenna holding groove 34 together. A portion of the top surface 38a of the positioning groove 38 faces the bottom surface 34a of the antenna holding groove 34.

[0060] As shown in Figure 3, two locking protrusions 40 are formed on the +Y edge 32c of the lid portion 32, positioned at different locations in the X direction. Two locking protrusions 40 are also formed on the -Y edge 32d of the lid portion 32, positioned at different locations in the X direction.

[0061] The locking projection 40 has a locking claw (not shown) at its tip. The locking projection 40 is inserted into the locking recess 39 of the main body 31. The locking claw of the locking projection 40 locks into the main body 31. As a result, the lid 32 is detachably connected to the main body 31.

[0062] The outer casing 3 is not fixed to the second antenna 2. In other words, the outer casing 3 is not fixed to the second antenna 2.

[0063] The communication device 10 can be installed in a molded product made of, for example, rubber, resin, or the like. For example, the communication device 10 can be embedded in the molded product. The molded product is, for example, an elastic body and is elastically deformable. If deformation such as stretching or bending occurs in the molded product, an external force may act on the second antenna 2. For example, a tensile force may act on the extension portion 22 in the direction away from the outer casing 3 along the X direction. A force may also act on the extension portion 22 in the direction approaching the outer casing 3 along the X direction. When installing the communication device 10 on the tire body 60 as in this embodiment, the communication device 10 can be provided so as to be enclosed in a fixing member (lamination rubber) made of a rubber sheet. This not only reliably prevents damage to the communication device 10, but if the communication device 10 is enclosed in the fixing member before being assembled into the tire 50, the communication device 10 can be easily and safely assembled into the tire 50 without the risk of damage.

[0064] [Effects of RF tags] In the communication device 10 of this embodiment, the electromagnetic field coupling portion 21 of the second antenna 2 is housed in the antenna holding groove 34 in a state that allows it to be displaced in the radial direction (a direction perpendicular to the longitudinal direction of the electromagnetic field coupling portion 21) (see Figure 7). Because the electromagnetic field coupling portion 21 is displaceable, the stress on the second antenna 2 can be relieved when an external force acts on it. Therefore, damage to the second antenna 2 can be made less likely. In contrast, if the second antenna is fixed to the outer casing, when an external force acts on the second antenna, stress concentrates at the base end (root portion) of the second antenna extending from the outer casing, and damage is more likely to occur at this point.

[0065] Since the electromagnetic field coupling portion 21 of the second antenna 2 has a shape that follows the outer peripheral edge 12a of the first antenna 12 on the substrate 1, the electromagnetic field coupling portion 21 can be sufficiently electromagnetically coupled to the first antenna 12. Since the antenna holding groove 34 is formed along the outer peripheral edge 12a of the first antenna 12, the electromagnetic field coupling portion 21 of the second antenna 2 can be positioned along the first antenna 12. Therefore, the electromagnetic field coupling portion 21 can be sufficiently electromagnetically coupled to the first antenna 12.

[0066] Because the electromagnetic field coupling portion 21 of the second antenna 2 has a curved shape (for example, a semi-elliptical shape), stress concentration is less likely to occur when an external force acts on the second antenna 2 compared to the case where it is rectangular. Therefore, damage to the second antenna 2 can be made less likely. In contrast, if the electromagnetic field coupling portion is rectangular, when an external force acts on the second antenna, stress will concentrate at the corners (bent parts), and damage may be more likely to occur at these points.

[0067] Since the antenna holding groove 34 is formed along the outer peripheral edge 13a of the substrate 1, the electromagnetic field coupling portion 21 of the second antenna 2 can be positioned along the first antenna 12. Therefore, the electromagnetic field coupling portion 21 can be sufficiently electromagnetically coupled to the first antenna 12.

[0068] The outer casing 3 comprises a main body 31 and a lid 32 that overlaps the holding surface 31a. The substrate holding recess 37 and the antenna holding groove 34 are formed in the holding surface 31a. Therefore, the lid 32 prevents the substrate 1 and the second antenna 2 from falling out of the main body 31. Thus, the substrate 1 and the second antenna 2 can be stably held in the outer casing 3.

[0069] In the communication device 10, a slit-shaped side end opening 36 extending in the Y direction (along the holding surface 31a) is formed on the side edge 31b of the outer casing 3. Therefore, the second antenna 2 can shift position in the Y direction relative to the outer casing 3. Consequently, when an external force acts on the second antenna 2, the stress is more easily relieved by displacement. Thus, damage to the second antenna 2 can be made less likely.

[0070] For example, in the communication device 10, the outer edge 13a of the substrate 1 and the outer edge 12a of the first antenna 12 are curved around their entire circumference, but the substrate and antenna may have only a portion of their outer edges curved. The casing 3 comprises a main body 31 and a lid 32, but the configuration of the casing is not particularly limited. For example, the casing may not have a lid. The casing is not limited to a plate shape, but may have other shapes (such as a block shape).

[0071] The following describes the features of the side covering rubber 57a near the communication device 10 with reference to Figures 8 to 10. Figure 8 is an enlarged view of the area near the communication device 10 in Figure 1. Figure 9 is an enlarged view of the area near the communication device 10 in a side view of the tire 50 shown in Figure 1, viewed from the outside in the tire width direction C. In Figure 9, the position of the communication device 10 is indicated by a dashed line. In other words, Figure 9 is also a front view of the protruding portion 80, which will be described later in this embodiment, viewed from the outer surface of the tire side portion 57. Figure 10 is a cross-sectional view taken along line II-II in Figure 9. In Figures 8 and 10, for the sake of explanation, the cross-sectional details of the communication device 10 are omitted. Also, in Figures 8 and 10, for the sake of explanation, members of the tire side portion 57 that are located inside the tire width direction C from the communication device 10 (for example, the carcass 54 shown in Figure 1) are omitted. As shown in Figures 8 to 10, the communication device 10 of this embodiment is embedded in the tire side portion 57 such that the X direction is aligned with the tire circumferential direction F. Also, as shown in Figures 8 to 10, the communication device 10 of this embodiment is embedded in the tire side portion 57 such that the Y direction is aligned with the tire radial direction E. Furthermore, as shown in Figures 8 to 10, the communication device 10 of this embodiment is embedded in the tire side portion 57 of the tire body 60 such that the Z direction is aligned with the tire width direction C.

[0072] As shown in Figures 8 and 10, the outer surface of the tire side portion 57 protrudes in the device area Q1. In other words, the side covering rubber 57a that constitutes the outer surface of the tire side portion 57 protrudes in the device area Q1. Here, "device area Q1" refers to the area where the communication device 10 is located in the tire radial direction E and the tire circumferential direction F of the tire side portion 57. That is, the device area Q1 in this embodiment refers to the area enclosed by the dashed line in Figure 9. In this way, by providing the protrusion 80 on the outer surface of the tire side portion 57 at a position that covers the communication device 10, the embedded position of the communication device 10 becomes easier to identify from outside the tire 50.

[0073] Furthermore, the thickness T of the side covering rubber 57a is thinner in the device area Q1 than the thickness around the device area Q1. The thickness T of the side covering rubber 57a refers to the thickness in the tire width direction C. A specific example of this will be explained below with reference to Figures 8 and 10. For the sake of explanation, in Figure 8, the area adjacent to the device area Q1 on one side in the tire radial direction E (in this embodiment, for example, the outside of the tire radial direction E) is defined as the first adjacent area Q2. Also, in Figure 8, the area adjacent to the device area Q1 on the other side in the tire radial direction E (in this embodiment, for example, the inside of the tire radial direction E) is defined as the second adjacent area Q3. In this case, as shown in Figure 8, the thickness T of the side covering rubber 57a is thinner in the device area Q1 than the thickness of the first adjacent area Q2 and the second adjacent area Q3 at the position adjacent to the device area Q1. In other words, the thickness T1 of the side covering rubber 57a in the device area Q1 is thinner than the thicknesses T2 and T3 of the side covering rubber 57a in the positions adjacent to the device area Q1 among the first adjacent area Q2 and the second adjacent area Q3, which are the periphery of the device area Q1 in the tire radial direction E. Here, in a cross-sectional view in the tire width direction at the location of the communication device 10 (see Figures 1 and 8), "position adjacent to the device area Q1 among the first adjacent area Q2" means a position within the first adjacent area Q2 that is 1 mm or less in the tire radial direction E from the boundary with the device area Q1. Similarly, in a cross-sectional view in the tire width direction at the location of the communication device 10 (see Figures 1 and 8), "position adjacent to the device area Q1 among the second adjacent area Q3" means a position within the second adjacent area Q3 that is 1 mm or less in the tire radial direction E from the boundary with the device area Q1.

[0074] Figure 8 compares the thickness T of the side covering rubber 57a in the device region Q1 and in the positions adjacent to the device region Q1 among the first adjacent region Q2 and the second adjacent region Q3, which are connected to the device region Q1 in the tire radial direction E. The same applies in the tire circumferential direction F. In Figure 10, the region connected to the device region Q1 on one side in the tire circumferential direction F is defined as the third adjacent region Q4. Also in Figure 10, the region connected to the device region Q1 on the other side in the tire circumferential direction F is defined as the fourth adjacent region Q5. In this case, as shown in Figure 10, the thickness T of the side covering rubber 57a is thinner in the device region Q1 than in the positions adjacent to the device region Q1 among the third adjacent region Q4 and the fourth adjacent region Q5. In other words, the thickness T1 of the side covering rubber 57a in the device area Q1 is thinner than the thickness T4 and T5 of the side covering rubber 57a in the third adjacent area Q4 and the fourth adjacent area Q5, which are the periphery of the device area Q1 in the tire circumferential direction F, and are adjacent to the device area Q1. Here, in a cross-sectional view of the tire side portion 57 in the tire circumferential direction at the location of the communication device 10 (see Figure 10), "the position adjacent to the device area Q1 in the third adjacent area Q4" means a position within the third adjacent area Q4 that is 1 mm or less in the tire circumferential direction F from the boundary with the device area Q1. Similarly, in a cross-sectional view of the tire side portion 57 in the tire circumferential direction at the location of the communication device 10 (see Figure 10), "the position adjacent to the device area Q1 in the fourth adjacent area Q5" means a position within the fourth adjacent area Q5 that is 1 mm or less in the tire circumferential direction F from the boundary with the device area Q1.

[0075] As described above, the thickness T of the side covering rubber 57a is thinner in the device area Q1 than the surrounding area Q1. By doing so, it is possible to suppress the concentration of strain in the protruding portion 80, which is the part that protrudes to indicate the position of the communication device 10, and improve the durability of the protruding portion 80.

[0076] Furthermore, the thickness T1 of the side covering rubber 57a in the device area Q1 does not have to be uniform within the device area Q1. In this case, "thickness T1 of the side covering rubber 57a in the device area Q1" means the maximum thickness of the side covering rubber 57a in the device area Q1. Also, the thicknesses T2 to T5 of the side covering rubber 57a around the device area Q1 in the tire radial direction E and the tire circumferential direction F do not have to be uniform. In this case, "thicknesses T2 to T5 of the side covering rubber 57a around the device area Q1 in the tire radial direction E and the tire circumferential direction F" means the minimum thickness of the side covering rubber 57a around the device area Q1 in the tire radial direction E and the tire circumferential direction F.

[0077] Furthermore, the protruding portion 80 of this embodiment is composed of a convex curved surface that, in a front view (see Figure 9) from the outer surface of the tire side portion 57, has a substantially circular base portion 80a and the central part of the same front view is the most protruding apex portion 80b. Therefore, as shown in Figure 8, in a cross-sectional view in the tire width direction at the location of the communication device 10, the protruding portion 80 of this embodiment has a convex shape in which the central part in the tire radial direction E is the most protruding. Also, as shown in Figure 10, in a cross-sectional view of the tire side portion 57 in the tire circumferential direction at the location of the communication device 10, the protruding portion 80 of this embodiment has a convex shape in which the central part in the tire circumferential direction F is the most protruding. In particular, as in this embodiment, it is preferable that the protruding portion 80 has a flared shape, changing from a convex curved surface portion to a concave curved surface portion from the apex portion 80b to the base portion 80a in both the tire radial direction E and the tire circumferential direction F. In other words, it is preferable that the protruding portion 80 has a flared shape, in a cross-sectional view in the tire width direction at the location of the communication device 10 (see Figure 8), where it changes from a convex curved portion L1 to a concave curved portion L2 via an inflection point CP1, from the top 80b in the central part of the tire radial direction E to the bottom 80a at both ends of the tire radial direction E. Similarly, it is preferable that the protruding portion 80 has a flared shape, in a cross-sectional view in the tire circumferential direction of the tire side portion 57 at the location of the communication device 10 (see Figure 10), where it changes from a convex curved portion L1 to a concave curved portion L2 via an inflection point CP1, from the top 80b in the central part of the tire circumferential direction F to the bottom 80a at both ends of the tire circumferential direction F.

[0078] By giving the protruding portion 80 such a flared shape, the base portion 80a of the protruding portion 80 and the outer surface of the tire side portion 57 surrounding the protruding portion 80 can be smoothly continuous, and the concentration of strain at the base portion 80a of the protruding portion 80 can be suppressed. In addition, since the portion including the top portion 80b of the protruding portion 80 is composed of a convex curved surface, the top portion 80b is less likely to become tapered compared to when the same portion is composed of a concave curved surface, and the concentration of strain near the top portion 80b due to various impacts from the outside of the tire 50 can be suppressed. In this way, by giving the protruding portion 80 a flared shape, which changes from a convex curved surface to a concave curved surface from the top portion 80b to the base portion 80a, the durability of the protruding portion 80 can be increased.

[0079] Furthermore, the protruding portion 80 only needs to be configured such that at least a part of it covers the communication device 10 on the outer surface of the tire side portion 57. Therefore, the protruding portion 80 may be provided so as to cover the entire communication device 10 on the outer surface of the tire side portion 57, or it may be provided so as to cover only a part of the communication device 10 on the outer surface of the tire side portion 57. However, as shown in Figures 8 to 10, it is preferable that the protruding portion 80 is provided so as to cover the entire communication device 10 on the outer surface of the tire side portion 57. In other words, in a front view of the protruding portion 80 (see Figure 9) as seen from the outer surface side of the tire side portion 57, it is preferable that the hem portion 80a, which is the outer edge of the protruding portion 80, is outside the device area Q1. By positioning the bottom portion 80a outside the device area Q1, the change in the thickness T of the side covering rubber 57a at the boundary between the device area Q1 and the area connected to the device area Q1 in the tire radial direction E and tire circumferential direction F (in this embodiment, the first to fourth adjacent areas Q2 to Q5) can be made more gradual compared to a configuration in which the bottom portion 80a is inside the device area Q1. This reduces the rigidity step at the boundary and suppresses the concentration of strain near the boundary. As a result, the durability of the tire 50 can be increased.

[0080] As shown in Figure 8, the maximum protrusion amount PL1 of the outer surface of the tire side portion 57 in the device region Q1 is preferably 0.1 to 1.0 mm. In this embodiment, as an example, it is set to 0.5 mm. The maximum protrusion amount PL1 refers to the maximum distance between the top portion 80b and the bottom portion 80a in the direction of the top normal parallel to the normal of the top portion 80b of the protrusion 80. By setting the maximum protrusion amount PL1 to 0.1 mm or more, the external visibility of the tire 50 can be ensured. By setting the maximum protrusion amount PL1 to 1.0 mm or less, the concentration of strain in the protrusion portion 80 can be suppressed. This prevents the protrusion portion 80 from becoming the starting point of cracks due to strain concentration. From the viewpoint of the external visibility of the tire 50, it is more preferable that the maximum protrusion amount PL1 be 0.2 mm or more, and even more preferable that it be 0.3 mm or more. From the viewpoint of suppressing strain concentration in the protruding portion 80, the maximum protrusion amount PL1 is more preferably 0.8 mm or less, and even more preferably 0.7 mm or less.

[0081] Furthermore, as shown in Figure 1, on the outer surface of the tire side portion 57, a mark portion 90 consisting of a protruding portion 90a is provided on at least one side in the tire radial direction E relative to the device area Q1 (in this embodiment, the outside in the tire radial direction E relative to the device area Q1). Here, the mark portion 90 can be, for example, the name of the manufacturer, the logo of the manufacturer, the product name of the tire 50, etc. The above-mentioned maximum protrusion amount PL1 (see Figure 8) of the outer surface of the tire side portion 57 in the device area Q1 is smaller than the maximum protrusion amount PL2 (see Figure 1) of the protruding portion 90a constituting the mark portion 90. The maximum protrusion amount PL2 means the maximum distance between the top portion 90a1 of the protruding portion 90a and the bottom portion 90a2 of the protruding portion 90a in the top normal direction parallel to the normal of the top portion 90a1 of the protruding portion 90a constituting the mark portion 90.

[0082] As described above, in the tire 50 of this embodiment, the communication device 10 is embedded in the tire side portion 57 of the tire body 60. In particular, as shown in Figure 1, the communication device 10 in this embodiment is sandwiched between the stiffener 51b2 and the side rubber 52a, which is the side covering rubber 57a adjacent to the stiffener 51b2, within the tire side portion 57. However, the position of the communication device 10 may be at other positions within the tire side portion 57. Hereinafter, possible positions for the communication device 10 in a cross-sectional view of the tire 50 in the tire width direction will be illustrated with reference to Figure 11. In Figure 11, in addition to the positions of the communication device 10 shown in Figures 1 and 8 to 10 (shown as white rectangles in Figure 11), examples of possible positions for the communication device 10 are shown as black rectangles.

[0083] As described above, the communication device 10 in this embodiment is an RF tag. Hereinafter, the communication device 10 will simply be referred to as an RF tag. As described above, the RF tag comprises an IC chip 11 and an antenna (in this embodiment, a first antenna 12 on the substrate 1 and a second antenna 2). The RF tag may, for example, be embedded in the rubber member constituting the side rubber 52a. Furthermore, it is preferable that the RF tag is not placed at a position that is the boundary between members with different rigidity in the peripheral length direction, which is the direction along the outer surface of the tire in a cross-sectional view in the tire width direction. By doing so, the RF tag is not placed at a position where strain is likely to concentrate due to the difference in rigidity. Therefore, the load applied to the RF tag can be reduced. This improves the durability of the RF tag. In this example, it is preferable that the RF tag is not placed at a position that is the boundary between, for example, the folded end 54a of the carcass 54 and a member adjacent to the folded end 54a of the carcass 54 in a cross-sectional view in the tire width direction. The number of RF tags is not particularly limited. The tire 50 may be equipped with only one RF tag, or it may be equipped with two or more RF tags. Here, an RF tag is used as an example of a communication device, but a different communication device may be used.

[0084] As shown in Figure 11, the RF tag may be positioned between the carcass 54 and the side rubber 52a (see reference numeral "P1" in Figure 11). The RF tag may be positioned, for example, between the position of the tire's maximum width and the position of the tread surface in the tire's radial direction E (see the symbol "P1" in Figure 11). This configuration improves communication with the RF tag from the outside of the tire 50 in the tire's radial direction E compared to a configuration where the RF tag is positioned inside the tire's maximum width in the tire's radial direction E. The RF tag may be positioned, for example, inward in the radial direction E of the tire from the position of the tire's maximum width (see the symbol "P2" in Figure 11). In this way, the RF tag is positioned near the highly rigid bead portion 51. Therefore, the load on the RF tag can be reduced. This improves the durability of the RF tag. In particular, it is preferable that the RF tag be positioned inside the tire radially E from the position of the tire's maximum width, and outside the bead core 51a of the bead portion 51 in the tire radially E (see the symbol "P2" in Figure 11). By doing so, the durability of the RF tag can be improved, and communication between the RF tag and the reader is less likely to be hindered by the bead core 51a, thereby improving the communication performance of the RF tag. Furthermore, if the side rubber 52a is composed of multiple identical or different rubber members adjacent to each other in the tire radial direction E, the RF tag may be positioned sandwiched between the multiple rubber members that make up the side rubber 52a.

[0085] The RF tag may be positioned sandwiched between the nylon chafer 51d and another adjacent member on the outside of the nylon chafer 51d in the tire width direction C. This arrangement makes it less likely for the RF tag's position to change during tire deformation. Therefore, the load applied to the RF tag during tire deformation can be reduced. This improves the durability of the RF tag. The nylon chafer 51d may, for example, have a portion adjacent to the side rubber 52a on the outer side C in the tire width direction. In such a case, the RF tag may be positioned sandwiched between the nylon chafer 51d and the side rubber 52a (see reference numeral "P2" in Figure 11).

[0086] The pneumatic tire according to the present invention is not limited to the specific configurations shown in the embodiments and modifications described above, and various modifications, changes, and combinations are possible as long as they do not depart from the scope of the claims.

[0087] [Contribution to the United Nations-led Sustainable Development Goals (SDGs)] The SDGs have been proposed to realize a sustainable society. One embodiment of this invention is considered to be a technology that can contribute to "No. 12: Responsible Consumption and Production" and "No. 13: Climate Action," among others. [Industrial applicability]

[0088] This invention relates to a pneumatic tire. [Explanation of Symbols]

[0089] 1: Circuit board 2: Second antenna 3: Exterior 10: Communication device 11: IC chip 12: First Antenna 12a: Outer edge 13: Base material 13a: Outer edge 21: Electromagnetic field coupling part 21a: End of electromagnetic field coupling 22: Extension part 22A: 1st extension part 22B: Second extension part 23: Straight section 23A: 1st straight section 23B: 2nd straight section 23C: 3rd straight section 24: Folded section 24A: First folding section 24B: Second folding section 31: Main body 31a: Holding surface 31b: Side edge 31c: edge 31d:Edge 32: Lid 32a: Opposite surface 32c: edge 32d:Edge 33: Substrate holding protrusion 34: Antenna retaining groove 34a: Bottom 35: Side recess 35a: Periphery 35b: 1st straight section 35c: Curved section 35d: 2nd straight section 36: Side opening 37: Substrate holding recess 38: Positioning groove 38a: Top surface 39: Locking recess 40: Locking protrusion 50: Tires 51: Bead section 51a: Bead core 51b, 51b1, 51b2: Stiffener 51c: Rubber chafer (an example of side-covered rubber) 51d: Nylon Chafer 51e: Wire Chafer 51f: Hat elastic 52: Sidewall section (an example of a tire sidewall) 52a: Side rubber (an example of side covering rubber) 53: Tread section 53a: Tread rubber 53b: Cushion rubber 54: Carcass 54a: Folded end 55: Belt 55a~55d: Belt ply 56: Inner Liner 57: Tire sidewall 57a: Side covering rubber 60: Tire body 80:Protrusion 80a: Hem 80b:Top 90: Emblem Section 90a:Protrusion 90a1:Top 90b2: Hem A: Thickness direction of the second antenna B: In-plane direction of the second antenna C: Tire width direction CL: Tire equatorial plane CP1: Inflection point D1: Outer diameter of the electromagnetic field coupling section E: Tire radial direction F: Circumferential direction of the tire H1: Height from the bottom of the antenna retaining groove to the lid. L1: Convex curved part L2: Concave curved part PL1: Maximum protrusion of the outer surface of the tire sidewall in the device area. PL2: Maximum protrusion amount of the protruding part that constitutes the emblem. Q1: Equipment area Q2: 1st adjacent area Q3: Second adjacent area Q4: Third adjacent area Q5: Fourth adjacent area T: Thickness of the side covering rubber T1: Thickness of the side covering rubber in the device area T2, T3: Thickness of the side covering rubber around the tire in the radial direction of the device area. T4, T5: Thickness of the side covering rubber around the tire in the circumferential direction of the device area. W1: Width of the antenna retaining groove P1, P2: Possible placement locations for communication devices

Claims

1. A tire body having a tire sidewall whose outer surface is made of side covering rubber, The tire body comprises a communication device embedded in the tire side portion, When the area in the tire radial direction and tire circumferential direction of the tire side portion where the communication device is located is defined as the device area, The outer surface of the tire side portion protrudes in the device area. A pneumatic tire in which the thickness of the side covering rubber is thinner in the device area than the thickness of the surrounding area of ​​the device area.

2. The pneumatic tire according to claim 1, wherein the maximum protrusion of the outer surface of the tire side portion in the device area is 0.1 to 1.0 mm.

3. On the outer surface of the tire side portion, at least one side in the tire radial direction relative to the device area is provided with a marking portion consisting of a protruding portion. The pneumatic tire according to claim 2, wherein the maximum protrusion amount of the outer surface of the tire side portion in the device area is smaller than the maximum protrusion amount of the protrusion portion constituting the mark portion.

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