Tire

Abstract

Provided is a tire in which durability of a housing member and output stability of a functional component can be improved. This tire comprises a functional component for detecting tire information, and a housing member 10 for accommodating the functional component. The housing member 10 is fixed to a tire inner surface Ts by a curable adhesive A, and a spacer M of a uniform thickness is disposed between the housing member 10 and the tire inner surface Ts.

Description

tire

[0001] The present invention relates to a tire equipped with a functional component having a sensor function for detecting tire information, and more particularly to a tire that enables improvements in the durability of the housing and the output stability of the functional component.

[0002] Functional components (e.g., sensor units including sensors) that acquire internal tire information such as internal pressure and temperature are installed on the inner surface of the tire (see, for example, Patent Documents 1 and 2). When attaching a housing to the inner surface of the tire to accommodate such functional components, the housing can be fixed to the inner surface of the tire using, for example, double-sided tape or adhesive. However, in the case of double-sided tape, although it has excellent dimensional stability, it has the problem of poor adhesion, making it difficult to ensure sufficient durability. In the case of adhesive, although it has excellent adhesion, it is difficult to control the thickness of the adhesive when applying the adhesive and attaching the housing, resulting in uneven thickness with locally thin areas. Because the thickness of the adhesive is not uniform, it is not possible to accurately detect changes in physical quantities caused by deformation of the tread, which leads to a problem of poor output stability.

[0003] Japanese Patent No. 6272225 Publication Japanese Special Table No. 2016-505438

[0004] The objective of the present invention is to provide a tire that enables improved durability of the housing and improved output stability of the functional components.

[0005] To achieve the above objective, the present invention provides a tire comprising a functional component for detecting tire information and a housing for housing this functional component, characterized in that the housing is fixed to the inner surface of the tire with a hardening adhesive, and a spacer of constant thickness is placed between the housing and the inner surface of the tire.

[0006] In this invention, the housing is fixed to the inner surface of the tire with a hardening adhesive, and a spacer of constant thickness is placed between the housing and the inner surface of the tire. This spacer ensures that the adhesive thickness between the housing and the inner surface of the tire is at least equal to the thickness of the spacer, thus stabilizing and uniformizing the adhesive thickness. As a result, sufficient adhesive strength of the adhesive can be ensured, improving the durability of the housing (resistance to peeling of the housing), and changes in physical quantities caused by deformation of the tread can be detected with high accuracy, thereby improving the output stability of the functional component.

[0007] In this invention, the spacer can be constructed with a mesh-like layer. This allows the adhesive to permeate into the spacer, ensuring a sufficient bonding area between the housing and the inner surface of the tire, thereby effectively improving the durability of the housing. Furthermore, the mesh-like layer allows it to conform to repeated deformation of the tire, preventing the spacer from breaking or being damaged.

[0008] The mesh-like layer is preferably made of organic fibers. This gives the spacer both flexibility and strength, allowing it to follow repeated deformations of the tire and preventing breakage or damage to the spacer.

[0009] The diameter of the organic fibers is preferably in the range of 0.1 mm to 0.7 mm. This allows for both the ability to follow repeated deformation of the tire and the strength of the organic fibers themselves, thereby improving the durability of the mesh-like layer while preventing breakage or damage to the spacer.

[0010] The maximum width of the spacer hole is preferably in the range of 0.5 mm to 5.1 mm. This allows for both increased productivity and uniformity of the adhesive thickness.

[0011] The shape of the hole in the spacer is preferably hexagonal. This provides flexibility to follow deformation in various directions and fatigue resistance, thus preventing breakage or damage to the spacer. Furthermore, since it forms a honeycomb structure in the thickness direction, it has excellent dimensional stability and contributes to uniformity of the adhesive thickness.

[0012] The material constituting the spacer has a modulus of elasticity in the range of 1×10 6 Pa to 1×10 10 Pa, and preferably has a surface free energy in the range of 25 mJ / m 2 to 70 mJ / m 2 . Thereby, the adhesive force of the adhesive can be sufficiently ensured, so that the durability of the container and the output stability of the functional components can be effectively improved.

[0013] Alternatively, the spacer can be composed of granular additives. Thereby, the adhesive force of the adhesive can be sufficiently ensured, so that the durability of the container and the output stability of the functional components can be effectively improved.

[0014] The thickness T M of the spacer is preferably in the range of 0.2 mm to 1.5 mm. Thereby, the thickness of the adhesive between the container and the inner surface of the tire can be sufficiently ensured through the spacer, so that the durability of the container can be effectively improved. Also, since the followability to the repeated deformation of the tire can be obtained, breakage or damage of the spacer can be prevented.

[0015] The thickness T A of the adhesive directly below the central region of the container and the thickness T M of the spacer preferably satisfy the relationship of 1.0 ≦ T A / T M ≦ 2.0. Thereby, the output stability of the functional components can be effectively improved.

[0016] The storage modulus of elasticity of the adhesive at -40°C is in the range of 5.0×10 8 Pa to 1.0×10 10 Pa, and preferably the storage modulus of elasticity of the adhesive at 150°C is in the range of 1.0×10 6 Pa to 5.0×10 7 Pa. Thereby, the detachment of the container can be prevented against the repeated deformation and load applied during running. Also, even when heat is generated during running, the durability of the container can be sufficiently ensured.

[0017] The container has a bottom fixed to the inner surface of the tire, a side wall portion protruding from the bottom, a storage portion formed by the bottom and the side wall portion, and an opening communicating with the storage portion. The inclination angle of the side wall portion with respect to the bottom of the side wall portion measured on the outer wall side of the side wall portion in a state where the functional component is accommodated in the storage portion is smaller than the inclination angle of the side wall portion with respect to the bottom of the side wall portion measured on the outer wall side of the side wall portion in a state where the functional component is not accommodated in the storage portion, and it is preferable that the angle difference is in the range of 5° to 15°. In the container in a state of accommodating the functional component, excessive deformation can be prevented while ensuring a restraining force capable of sufficiently restraining the functional component. In particular, the balance between the restraining force of the container on the functional component and the degree of deformation that does not cause damage to the container is extremely good. Thereby, while preventing the functional component from falling off during traveling, damage to the container can be prevented.

[0018] The inclination angle of the side wall portion with respect to the bottom of the side wall portion measured on the outer wall side of the side wall portion in a state where the functional component is accommodated in the storage portion is preferably 90° or more. Thereby, stress concentration at the base of the side wall portion of the container can be alleviated, and the durability of the container can be improved. Furthermore, the opening of the container does not become excessively narrow, which is also suitable when removing the functional component.

[0019] The width of the opening is narrower than the minimum width of the storage portion, and the perimeter D2 of the upper portion of the storage portion u and the perimeter D1 of the upper portion of the functional component u satisfy the relationship of 0.60 ≤ D2 u / D1 u ≤ 0.95. Thereby, the restraining force of the container on the functional component can be increased, and the movement of the functional component can be suppressed, so that the housing of the functional component can be prevented from being damaged during high-speed traveling. Furthermore, since the balance between the restraining force of the container on the functional component and the degree of deformation that does not cause damage to the container is good, damage to the container can also be prevented.

[0020] Preferably, the modulus of the housing at 100% elongation at 20°C is 0.5 MPa or more and less than 10.0 MPa, and the loss modulus of the housing at 60°C is 0.4 MPa or more and less than 20.0 MPa. By setting the modulus appropriately in this way, it is possible to achieve both the durability of the housing and the ease of housing the functional components within it. Furthermore, by setting the loss modulus appropriately in this way, it is possible to prevent damage to the housing of the functional components caused by friction between the functional components and the housing, or by repeated deformation of the housing. The housing is also preferably made of vulcanized rubber.

[0021] The tire of the present invention is preferably a pneumatic tire, but may also be a non-pneumatic tire. In the case of a pneumatic tire, the inside can be filled with air, an inert gas such as nitrogen, or other gases.

[0022] Figure 1 is a meridian cross-sectional view showing an example of a pneumatic tire according to an embodiment of the present invention. Figure 2 is a perspective view showing a housing fixed to the pneumatic tire of Figure 1. Figure 3 is a perspective view showing the inside of the housing with a part of the housing of Figure 2 cut out. Figure 4 is a plan view showing the housing of Figure 2. Figure 5 is a cross-sectional view taken along the line V-V in Figure 4. Figures 6(A) to (C) are plan views showing the form of the spacer, respectively. Figures 7(A) to (D) illustrate the housing before and after housing the functional component, with Figure 7(A) being a perspective view of the state without the functional component, Figure 7(B) being a cross-sectional view of the state without the functional component, Figure 7(C) being a perspective view of the state with the functional component, and Figure 7(D) being a cross-sectional view of the state with the functional component. Figures 8(A) and (B) are half cross-sectional views of the housing to explain the dimensions of the housing, respectively. Figure 9 is a cross-sectional view showing an example of a housing fixed to a pneumatic tire. Figure 10 is a diagram showing an example of an output waveform from a piezoelectric element.

[0023] The configuration of the present invention will be described in detail below with reference to the attached drawings. Figure 1 shows a pneumatic tire according to an embodiment of the present invention, and Figures 2 to 5 show a housing fixed to the pneumatic tire.

[0024] As shown in Figure 1, the tire T comprises a tread portion 1 that extends in the circumferential direction of the tire and forms an annular shape, a pair of sidewall portions 2, 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3, 3 arranged radially inward of these sidewall portions 2.

[0025] A carcass layer 4 is mounted between a pair of bead portions 3, 3. This carcass layer 4 includes a plurality of reinforcing cords extending in the radial direction of the tire, and is folded back from the inside to the outside of the tire around the bead core 5 located in each bead portion 3. A bead filler 6 made of a rubber composition with a triangular cross-section is arranged on the outer circumference of the bead core 5. An inner liner layer 9 is arranged in the region between the pair of bead portions 3, 3 on the inner surface Ts of the tire. This inner liner layer 9 forms the inner surface Ts of the tire.

[0026] On the other hand, multiple belt layers 7 are embedded on the outer circumference of the carcass layer 4 in the tread portion 1. These belt layers 7 include multiple reinforcing cords that are inclined with respect to the tire circumferential direction, and the reinforcing cords are arranged to intersect each other between layers. In the belt layers 7, the inclination angle of the reinforcing cords with respect to the tire circumferential direction is set to, for example, a range of 10° to 40°. Steel cords are preferably used as the reinforcing cords of the belt layers 7. On the outer circumference of the belt layers 7, at least one belt cover layer 8 is arranged, in which the reinforcing cords are arranged at an angle of, for example, 5° or less with respect to the tire circumferential direction, for the purpose of improving high-speed durability. Organic fiber cords such as nylon or aramid are preferably used as the reinforcing cords of the belt cover layer 8.

[0027] The tire internal structure described above is a typical example of a pneumatic tire, but is not limited to this example.

[0028] In the above-described pneumatic tire, as shown in Figures 2 to 5, the housing 10 is fixed to the inner surface Ts of the tire via a hardening adhesive A. A spacer M having a substantially constant thickness is placed between the housing 10 and the inner surface Ts of the tire.

[0029] This spacer M is a material that forms a layer in one of the following forms, for example, a film, a mesh, a nonwoven fabric, a cord (strip), or a sphere. In any of these forms, there are or are formed multiple gaps in the spacer M, and the adhesive A permeates through these gaps, so that the adhesive A and the spacer M form an integrated layer. Therefore, the spacer M forms an intermediate layer, and its upper and lower layers are made of adhesive A.

[0030] Adhesive A has a storage modulus of 5.0 × 10⁻⁶ at -40°C. 8 Pa ~ 1.0 × 10 10 It is in the Pa range and has a storage modulus of 1.0 × 10⁻⁶ at 150°C. 6 Pa ~ 5.0 x 10 7 It is preferable that the storage modulus of elasticity is in the range of Pa. Examples of adhesives having such physical properties include instant adhesives, epoxy adhesives, acrylic adhesives, rubber adhesives, and urethane adhesives. As described above, by appropriately setting the storage modulus of elasticity of the adhesive, it is possible to prevent the housing 10 from falling off due to repeated deformation and load applied during driving. Furthermore, even if heat is generated during driving, sufficient durability of the housing 10 can be ensured.

[0031] The housing 10 has a flat bottom portion 11 fixed to the inner surface Ts of the tire, a cylindrical side wall portion 12 protruding from the bottom portion 11, a housing portion 13 formed by the bottom portion 11 and the side wall portion 12, and an opening 14 communicating with the housing portion 13. The housing 10 is preferably a molded body made of vulcanized rubber. For example, it is desirable to use the same butyl rubber as the inner surface Ts of the tire (inner liner layer 9), but butadiene rubber which has excellent repeated flexibility, natural rubber which has excellent strength, or a rubber compound which is a mixture of the two can also be used.

[0032] The bottom portion 11 is the longest part (has the largest diameter) of the parts constituting the housing 10. The side wall portion 12 is formed to slope inward from a direction perpendicular to the bottom portion 11. Therefore, the housing portion 13 formed by the bottom portion 11 and the side wall portion 12 has a roughly trapezoidal cross-sectional shape. That is, the cross-sectional width of the housing portion 13 gradually decreases towards the upper part, and the cross-sectional width is narrowest at the maximum height position. In addition, the side wall portion 12 has a locking portion 12e formed to bend toward the opening 14 at one end 12a, and the other end 12b is fixed to the bottom portion 11. After the functional component 20 is housed, the locking portion 12e abuts against the upper surface of the functional component 20 and plays a role in fixing the functional component 20 in place during housing. The width of the opening 14 into which the functional component 20 is inserted is narrower than the minimum width in the cross-sectional view of the housing portion 13 (width at a position adjacent to the opening 14).

[0033] In Figure 1, the bottom portion 11, the side wall portion 12, and the opening 14 all have a circular planar shape, and the storage portion 13 has the shape of a truncated cone. The planar shapes of the bottom portion 11, the side wall portion 12, and the opening 14 are not particularly limited and may be composed of any other planar shape, or may be composed of different planar shapes from each other. Also, the shape of the storage portion 13 is not particularly limited.

[0034] The functional component 20 has a contact surface 21 that contacts the inner surface Ts of the tire. That is, the contact surface 21 is the surface that contacts the bottom surface 13x of the housing 13. The functional component 20 also has a structure in which various electronic components are housed inside the housing 23. The electronic components can be configured to include various sensors for acquiring tire information, a transmitter, a receiver, a control circuit, and a battery. Examples of tire information acquired by the sensors include the internal temperature and pressure of the pneumatic tire, and the amount of wear on the tread. For example, a temperature sensor and a pressure sensor are used to measure the internal temperature and pressure. When detecting the amount of wear on the tire tread, for example, a sensor element 22 made of a film-like piezoelectric element is placed on the contact surface 21 of the functional component 20, and the sensor element 22 detects an output voltage corresponding to the tire deformation during driving, and the amount of wear on the tread is detected based on that output voltage. In addition, it is also possible to use an acceleration sensor or a magnetic sensor. The sensor element 22 can be placed on either the outer surface or the inner surface of the housing 23.

[0035] The internal structure of the functional component 20 described above is merely an example and is not limited thereto. The functional component 20 may be fixed to the housing 10 with adhesive tape or glue, or it may not be fixed to the housing 10.

[0036] In the pneumatic tire described above, the housing 10 is fixed to the inner surface Ts of the tire with a hardening adhesive A, and a spacer M of constant thickness is placed between the housing 10 and the inner surface Ts of the tire. As a result of this spacer M, the thickness of the adhesive A is ensured to be at least the thickness of the spacer M between the housing 10 and the inner surface Ts of the tire, thereby stabilizing and uniformizing the thickness of the adhesive A. This ensures sufficient adhesive strength of the adhesive A, improving the durability of the housing 10 (resistance to peeling of the housing 10), and also allows for accurate detection of changes in physical quantities caused by deformation of the tread portion 1, thereby improving the output stability of the functional component 20.

[0037] In the above-described pneumatic tire, the spacer M can be constructed from a mesh-like layer N1. For example, woven tulle can be used. As shown in Figure 6(A), the spacer M is constructed by combining warp threads m1 and weft threads m2 and has multiple holes g. The shape of the holes g can be formed from squares, triangles, rectangles, or hexagons. By constructing the spacer M from a mesh-like layer N1 in this way, the adhesive A can permeate into the interior of the spacer M, and a sufficient bonding area can be secured between the housing 10 and the inner surface Ts of the tire, thereby effectively improving the durability of the housing 10. Furthermore, because the mesh-like layer N1 has the ability to follow repeated deformation of the tire T, breakage or damage of the spacer M can be prevented.

[0038] Furthermore, the mesh-like layer N1 can be made of natural fibers such as silk, or inorganic fibers such as metal or carbon fiber, but it is preferable to make it of organic fibers. Examples of organic fibers include nylon, polyester, and rayon. By making the mesh-like layer N1 of organic fibers in this way, the spacer M has both flexibility and strength, so it can follow the repeated deformation of the tire T and prevent breakage or damage to the spacer M. This leads to an improvement in the durability of the spacer M.

[0039] The diameter d of the organic fiber described above is preferably in the range of 0.1 mm to 0.7 mm, and more preferably in the range of 0.4 mm to 0.5 mm. In this case, the warp thread m1 and weft thread m2 may be monofilaments or multifilaments. By setting the diameter d appropriately in this way, it is possible to achieve both the ability to follow the repeated deformation of the tire T and the strength of the organic fiber itself, thereby improving the durability of the mesh-like layer N1 while preventing the breakage or damage of the spacer M. If the diameter d of the organic fiber is 0.1 mm or more, it is possible to prevent the breakage or damage of the spacer M without impairing the strength of the thread, and if the diameter d of the organic fiber is 0.7 mm or less, it is possible to increase the strength of the thread without impairing the ability to follow the repeated deformation of the tire T. Note that the diameter d is the maximum width of the warp thread m1 and weft thread m2, respectively, as shown in Figure 6(A).

[0040] In the mesh-like layer N1, the maximum width w of the holes g of the spacer M is preferably in the range of 0.5 mm to 5.1 mm. Furthermore, the area of ​​the holes g of the spacer M is preferably in the range of 20% to 95% of the total area of ​​the spacer M including the holes g, and more preferably in the range of 20% to 80%. By appropriately setting the maximum width w of the holes g in this way, it is possible to achieve both productivity and uniformity of the thickness of the adhesive A. This leads to further improvement in the output stability of the functional component 20. If the maximum width w of the holes g is 0.5 mm or more, the adhesive A can penetrate the spacer M without worsening productivity, and if the maximum width w of the holes g is 5.1 mm or less, a good balance can be obtained between improved productivity and uniformity of the thickness of the adhesive A.

[0041] Furthermore, the shape of the hole g of the spacer M can be circular, triangular, square, rectangular, parallelogram, rhombus, hexagon, etc., but a hexagon as shown in Figure 6(B) is particularly preferable. Also, knitted fabric may be used as the material m3 that makes up the spacer M. By configuring the shape of the hole g of the spacer M as a hexagon, it is possible to prevent fracture and damage to the spacer M because it has the ability to follow deformation in various directions and fatigue resistance. In addition, because it is hexagonal, it has a honeycomb structure in the thickness direction, so it has excellent dimensional stability and contributes to the uniformity of the thickness of the adhesive A, which leads to further improvement in the output stability of the functional component 20.

[0042] The material that makes up spacer M has an elastic modulus of 1 × 10 6 Pa ~ 1 x 10 10 It is in the Pa range and has a surface free energy of 25 mJ / m 2 ~70 mJ / m 2It is preferable that the material is within this range. Examples of materials having such physical properties include nylon 6, nylon 66, nylon 12, nylon 11, nylon 46, nylon 6T, nylon 9T, nylon MXD6, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), polylactic acid, cotton, silk, hemp, etc. By having such physical properties in the material constituting the spacer M, the adhesive strength of adhesive A can be sufficiently ensured, thereby effectively improving the durability of the containment 10 and the output stability of the functional component 20. In contrast, if, for example, Teflon (registered trademark), which has a low surface free energy, is used, the adhesion is poor, and the durability of the containment and the output stability of the functional component tend to deteriorate. Surface free energy is measured in accordance with JIS K6768.

[0043] Alternatively, the spacer M can be composed of granular additives N2. Beads can be used as an example of granular additives N2, but inorganic materials such as glass beads are preferable. In this case, as shown in Figure 6(C), it is preferable to use multiple materials m4 consisting of spheres with a substantially constant maximum diameter and to disperse them. By composing the spacer M with granular additives N2 in this way, the adhesive strength of the adhesive A can be sufficiently ensured, thereby effectively improving the durability of the housing 10 and the output stability of the functional component 20.

[0044] In the above-mentioned pneumatic tire, the thickness T of the spacer M M (See Figure 5) is preferably in the range of 0.2 mm to 1.5 mm. M By setting it appropriately, the thickness T of the adhesive A between the housing 10 and the inner surface Ts of the tire is controlled via the spacer M. A Because sufficient space can be secured, the durability of the housing 10 can be effectively improved. In addition, because the ability to follow the repeated deformation of the tire T can be obtained, breakage or damage of the spacer M can be prevented. Thickness T M If the thickness of the adhesive A is 0.2 mm or more, the durability of the spacer M will not be reduced. A This ensures sufficient thickness TM If the thickness is 1.5 mm or less, it is possible to avoid deterioration in the tire T's ability to follow deformation and damage to the adhesive A.

[0045] Thickness T of adhesive A directly below the central region of the containment body 10 A (See Figure 5) and the thickness T of spacer M M This means that 1.0 ≤ T A / T M It is preferable to satisfy the relationship ≤ 2.0. The central region of the housing 10 refers to the region with a radius of 5 to 10 mm from the center of the housing 10. By satisfying the above relationship directly below this central region of the housing 10, the thickness of the adhesive A is stabilized, and the output stability of the functional component 20 can be effectively improved. Note that the thickness of the adhesive A is T. A The thickness T of the spacer M between the housing 10 and the inner surface Ts of the tire. M The thickness includes [the specified element].

[0046] Figures 7(A) to 7(D) show the housing before and after the housing of the functional components. Figures 7(A) and 7(B) show the state in which the functional components 20 are not housed in the housing 10, while Figures 7(C) and 7(D) show the state in which the functional components 20 are housed in the housing 10.

[0047] As shown in Figures 7(A) to (D), it is preferable that the inclination angle θ2 of the side wall portion 12 with respect to the bottom 11 when the functional component 20 is housed in the housing portion 13 is smaller than the inclination angle θ1 of the side wall portion 12 with respect to the bottom 11 when the functional component 20 is not housed in the housing portion 13. Both of these inclination angles θ1 and θ2 are angles measured on the outer wall side of the side wall portion 12. When the functional component 20 is housed in the housing portion 13 through the opening 14, it is preferable that the side wall portion 12 tilts outward and deforms so that the width of the opening 14 expands, thereby reducing the inclination angle θ of the side wall portion 12 with respect to the bottom 11. It is preferable that the angle difference (θ1 - θ2) between the inclination angle θ1 before the functional component 20 is housed and the inclination angle θ2 after the functional component 20 is housed be in the range of 5° to 15°.

[0048] Here, when measuring the inclination angle θ(θ1, θ2) of the side wall portion 12, the angle can be calculated using a CT scan or the like. Also, only when measuring the inclination angle θ of the side wall portion 12, as shown in Figure 8(A), the straight line L1 passing through two points on the outer surface of the side wall portion 12, at positions 1 / 2 (0.5 × H) and 1 / 4 (0.25 × H) of the total height H of the housing 10, is considered as the side wall portion 12, and the inclination angle θ1 before housing the functional component 20 and the inclination angle θ2 after housing the functional component 20 are measured, respectively. The total height H (maximum height H) of the housing 10 changes before and after housing the functional component 20, and the inclination angle θ(θ1, θ2) of the side wall portion 12 is measured based on each height. Furthermore, if a projection is formed on the outer surface of the side wall portion 12 at a position half and / or one-quarter of the total height H of the housing 10, the inclination angle θ of the side wall portion 12 shall be measured based on a straight line defined with the lower end of the projection as a new reference point, without including the projection. The total height H of the housing 10 is the height from the lower surface of the bottom portion 11 to the upper surface of the locking portion 12e.

[0049] In this way, by setting the inclination angle θ2 of the side wall 12 relative to the bottom 11, measured on the outer wall side of the side wall 12 when the functional component 20 is housed in the housing 13, to be smaller than the inclination angle θ1 of the side wall 12 relative to the bottom 11, measured on the outer wall side of the side wall 12 when the functional component 20 is not housed in the housing 13, it is possible to prevent excessive deformation while ensuring sufficient restraining force to hold the functional component 20 in the housing 10 when the functional component 20 is housed. In particular, by setting the angle difference (θ1 - θ2) of the inclination angle before and after housing the functional component 20 in the range of 5° to 15°, an extremely good balance is achieved between the restraining force of the housing 10 on the functional component 20 and the degree of deformation that does not cause damage to the housing 10. As a result, it is possible to prevent damage to the housing 10 while preventing the functional component 20 from falling out during travel.

[0050] Here, if the angle difference of the inclination angle (θ1 - θ2) becomes less than 5°, the restraining force of the housing 10 on the functional component 20 decreases, increasing the risk of the functional component 20 falling off during driving, and also increasing the movement of the functional component 20, thus reducing the durability of the housing 10. Conversely, if the angle difference of the inclination angle (θ1 - θ2) becomes greater than 15°, the deformation of the housing 10 becomes excessively large, making it more likely for cracks to occur in the housing 10 during long-distance driving.

[0051] As shown in Figure 9, when measuring the inclination angles θ1 and θ2 with the housing 10 fixed to the inner surface of the tire, the angle between the side wall portion 12 and the straight line L2 passing through the other end 12b of the side wall portions 12 on both sides in a cross-sectional view is measured. Furthermore, even if the housing does not have a member corresponding to the bottom and the side walls are directly fixed to the inner surface of the tire, the measurement can be performed in the same manner as described above.

[0052] In the above-described pneumatic tire, with the functional component 20 housed in the housing 13, the inclination angle θ2 of the side wall 12 with respect to the bottom 11 is preferably 90° or more, and more preferably in the range of 90° to 115°. By appropriately setting the inclination angle θ2 after housing the functional component 20 in this way, stress concentration at the base of the side wall 12 of the housing 10 can be alleviated, and the durability of the housing 10 can be improved. Furthermore, the opening 14 of the housing 10 does not become excessively narrow, which is also preferable when removing the functional component 20.

[0053] Here, if the inclination angle θ2 after the functional component 20 is housed becomes less than 90°, stress concentration at the base of the side wall portion 12 of the housing 10 increases, and strain energy during travel also increases, making it easier for cracks to occur at the base of the side wall portion 12. On the other hand, if the inclination angle θ2 after the functional component 20 is housed becomes greater than 115°, the tilt of the side wall portion 12 remains excessively large even after the functional component 20 is housed, so the width of the opening 14 becomes excessively narrow, making it difficult to remove the functional component 20.

[0054] Furthermore, the width of the opening 14 is narrower than the minimum width of the storage section 13, and the circumference D2 of the upper part of the storage section 13 u and the circumference D1 of the upper part of the functional component 20 uThis means 0.60 ≤ D2 u / D1 u It is preferable that the relationship ≤ 0.95 is satisfied. That is, the circumference D2 of the housing portion 13 u The circumference D1 of the functional component 20 u The intention is to increase the restraining force by the housing 10 by setting it to a smaller value within a specific range. Here, the circumference D2 of the housing section 13 u As shown in Figure 8(B), in the state before housing the functional component 20, the height of the housing 10 is defined as h2, which is 3 / 4 of the total inner height H2 (0.75 × H2). The circumference of the housing 13 is measured at three positions: at this height h2, and at positions corresponding to ±25% of height h2 (0.25 × h2) relative to the height h2 position. The circumferences measured at these three positions are then averaged. In addition, the circumference D1 of the upper part of the functional component 20 is also calculated. u This is obtained by measuring the circumference of the functional component 20 at positions corresponding to the three positions mentioned above, and averaging the circumferences measured at these three positions.

[0055] Thus, the circumference D2 of the housing section 13 u and the circumference D1 of the functional part 20 u By setting this appropriately, the restraining force of the housing 10 on the functional component 20 can be increased, suppressing the movement of the functional component 20, thereby preventing damage to the housing 23 of the functional component 20 during high-speed driving. Furthermore, because there is a good balance between the restraining force of the housing 10 on the functional component 20 and the degree of deformation that does not cause damage to the housing 10, damage to the housing 10 can also be prevented.

[0056] Here, ratio D2 u / D1 u If the ratio D2 is less than 0.60, the restraining force of the housing 10 increases, but the degree of deformation of the side wall 12 also increases, so the possibility of cracks occurring in the housing 10 during long-distance travel and the housing 10 being damaged increases. Conversely, ratio D2 u / D1 u If the value is greater than 0.95, the restraining force of the housing 10 decreases, and the movement of the functional component 20 within the housing 10 increases. As a result, heat generation increases due to friction between the housing 10 and the functional component 20, raising concerns that the housing 23 of the functional component 20 may be damaged during high-speed driving.

[0057] In the above-described pneumatic tire, the constituent material of the housing 10 preferably has the following physical properties. The modulus of the housing 10 when stretched to 100% at 20°C is preferably 0.5 MPa or more and less than 10.0 MPa, and the loss modulus of the housing 10 at 60°C is preferably 0.4 MPa or more and less than 20.0 MPa. By setting the modulus appropriately in this way, it is possible to achieve both the durability of the housing 10 and the ease of housing the functional component 20 in the housing 10. Furthermore, by setting the loss modulus appropriately in this way, it is possible to prevent damage to the housing 23 of the functional component 20 caused by friction of the functional component 20 against the housing 10 and repeated deformation of the housing 10.

[0058] The tire size is 225 / 45ZR18, and it comprises a functional component for acquiring tire information and a housing for housing this functional component. The housing is fixed to the inner surface of the tire, and the information acquired includes the presence or absence of a spacer, the type of adhesive layer, the shape of the spacer, the material of the mesh layer, the wire diameter of the fibers, the maximum width of the hole, the shape of the hole, and the thickness T of the spacer. M , ratio T A / T M Conventional, comparative, and example 1-22 tires were manufactured with the parameters set as shown in Tables 1 and 2. The functional component has a sensor function using a piezoelectric element as a sensor element, and the functional component is mounted on the back surface of the tread portion via a housing.

[0059] For these test tires, the output stability of the functional components, the durability of the housing, the durability of the spacer, and productivity were evaluated using the test methods described below, and the results are shown in Tables 1 and 2.

[0060] Output Stability: Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ and placed on a drum testing machine. A driving test was conducted with an air pressure of 230 kPa, a load of 60% of the maximum load capacity, and a speed of 30 km / h, and the output detected by the sensor element (piezoelectric element) was recorded. Figure 10 shows an example of the output waveform from the piezoelectric element. In this output waveform, as the part of the tread where the functional component is installed makes contact with the ground, negative and positive peaks are sequentially formed in the output of the piezoelectric element over time T, and a peak-to-peak value V is obtained. The average value Vave and standard deviation σ of the peak-to-peak value V of the output waveform obtained in each of the 10 measurements were calculated, and the coefficient of variation CV (CV = σ / Vave) was calculated. The evaluation results are shown as an index using the reciprocal of the coefficient of variation CV, with the conventional example set to 100. A larger index value indicates better output stability. This output stability was evaluated.

[0061] Durability (resistance to peeling): Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ, and a running test was conducted on a drum testing machine under the conditions of an air pressure of 160 kPa, 100% of the maximum load, and a running speed of 80 km / h. The evaluation results were shown in three stages: "◎ (Excellent)" if the contents did not peel off after a running distance of 6,000 km to 7,000 km, "○ (Good)" if the contents did not peel off after a running distance of 4,000 km to less than 6,000 km, and "× (Poor)" if the contents peeled off after a running distance of less than 4,000 km.

[0062] Spacer Durability: Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ, and a driving test was conducted on a drum testing machine under the following conditions: air pressure of 170 kPa, 80% of the maximum load, driving speed of 60 km / h, and slip angle of ±3°, until the spacer broke. The distance traveled at the time of breakage was measured. The evaluation results are shown as an index with Example 1 set to 100. A higher index value indicates better spacer durability.

[0063] Productivity: When fixing the housing to the inner surface of each test tire, the time it took for the adhesive to penetrate the spacer was measured. The evaluation results were shown as follows: if the penetration time was 15 seconds or less, it was shown as "◎ (Excellent)"; if the penetration time was between 15 seconds and 30 seconds, it was shown as "〇 (Good)"; and if the penetration time was between 30 seconds and 60 seconds, it was shown as "△ (Acceptable)".

[0064]

[0065]

[0066] As can be seen from Tables 1 and 2, the pneumatic tires of Examples 1 to 22 achieved both stable output of functional components and durable housing (resistance to peeling) compared to conventional examples. The pneumatic tires of Examples 5 to 22 showed further improved spacer durability. The pneumatic tires of Examples 17 to 22 showed further improved productivity.

[0067] In the comparative example, the pneumatic tire used double-sided tape as the adhesive layer, which resulted in a deterioration of the durability (resistance to peeling) of the container.

[0068] Furthermore, the tire size is 225 / 45ZR18, and it comprises a functional component for acquiring tire information and a housing for housing this functional component. The housing is fixed to the inner surface of the tire with a hardening adhesive, and a spacer is placed between the housing and the inner surface of the tire. The housing has a bottom fixed to the inner surface of the tire, a side wall protruding from the bottom, a housing formed by the bottom and the side wall, and an opening communicating with the housing. The thickness of the spacer is T. M Set to 0.4 mm, and the thickness T of the adhesive directly below the central region of the containment. A and spacer thickness T M T A / T M Set to 1.5, the inclination angle of the side wall before storage θ1, the inclination angle of the side wall after storage θ2, the angle difference between the inclination angles before and after storage (θ1 - θ2), ratio D2 u / D1 u Tires for Examples 23 to 34 were manufactured with the settings shown in Table 3.

[0069] For these test tires, the output stability, presence or absence of detachment, ease of removal, and high-speed durability of the functional components were evaluated using the test methods described below. The durability (resistance to peeling), crack resistance, and durability (damage or crack occurrence) of the housing were also evaluated, and the results are shown in Table 3. The output stability of the functional components and the durability (resistance to peeling) of the housing were evaluated in the same manner as described above. In this case, the output stability of the functional components was expressed as an index with Example 23 set to 100.

[0070] Detachment of functional parts: Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ, and a load of 88% of the maximum load at an air pressure of 200 kPa was applied. A running test was conducted on a drum testing machine under the conditions of -20°C, air pressure of 160 kPa, and running speed of 81 km / h. Specifically, one cycle consisted of running under the above conditions and then letting the tire cool for a certain period of time. This was repeated 50 times, after which the presence or absence of detachment of functional parts was visually checked. The evaluation results indicate whether or not detachment of functional parts occurred.

[0071] Removability (Functional Components): For each test tire's housing with functional components, the process of removing the functional components inserted into the housing was repeated 10 times, and the time required for each removal was measured. The evaluation results were shown in three stages: "◎ (Excellent)" if the time required for each of the 10 removals was 20 seconds or less, "○ (Good)" if the time required for each of the 10 removals was between 20 seconds and 60 seconds, and "× (Poor)" if the time required for each of the 10 removals was over 60 seconds.

[0072] High-speed durability (functional components): Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ, and a running test was conducted on a drum testing machine under conditions of a load of 88% of the maximum load capacity and an air pressure of 360 kPa. Specifically, the speed was increased by 10 km / h every 10 minutes starting from an initial speed of 120 km / h, and the test was continued until damage occurred to the housing of the functional component, and the distance traveled was measured. The evaluation results are shown as an index with the measured value of Example 23 set to 100. A higher index value indicates better high-speed durability.

[0073] Crack Resistance (Container): Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ, subjected to degradation treatment in an oxygen atmosphere at 80°C for 5 days, and then subjected to a running test on a drum testing machine under a load of 80% of the maximum load capacity and an air pressure of 250 kPa. Specifically, the speed was increased by 10 km / h every 24 hours from an initial speed of 120 km / h until a speed of 170 km / h was reached, after which the occurrence of cracks or wrinkles in the containment was visually checked. The evaluation results were shown in three stages: "◎ (Excellent)" if there were no cracks or wrinkles, "○ (Good)" if there were only wrinkles, and "× (Unacceptable)" if there were cracks.

[0074] Durability (container): Each test tire was mounted on a wheel with a rim size of 18 x 7 1 / 2 JJ, and a running test was conducted on a drum testing machine under the following conditions: air pressure of 540 kPa, 160% of the maximum load, running speed of 81 km / h, and running distance of 20,000 km. After the test, damage and cracking of the containment were visually inspected. The evaluation results were shown in three stages: "◎ (Excellent)" if there was no damage or cracking, "○ (Good)" if there were only cracks, and "× (Unacceptable)" if there was damage.

[0075]

[0076] As can be seen from Table 3, the pneumatic tires of Examples 24 to 34 showed improved resistance to detachment of functional components compared to Example 23. In particular, the pneumatic tires of Examples 32 and 33 showed a good balance of improved high-speed durability of functional components and crack resistance of the housing.

[0077] 1 Tread section 2 Sidewall section 3 Bead section 10 Housing section 11 Bottom section 12 Side wall section 13 Housing section 14 Opening 20 Functional parts A Adhesive M Spacer T Pneumatic tire Ts Inner surface of tire

Claims

1. A tire comprising a functional component for detecting tire information and a housing for housing this functional component, wherein the housing is fixed to the inner surface of the tire with a hardening adhesive, and a spacer of constant thickness is placed between the housing and the inner surface of the tire.

2. The tire according to claim 1, characterized in that the spacer is a mesh-like layer.

3. The tire according to claim 2, characterized in that the mesh-like layer is made of organic fibers.

4. The tire according to claim 3, characterized in that the wire diameter of the organic fiber is in the range of 0.1 mm to 0.7 mm.

5. The tire according to any one of 2 to 4, characterized in that the maximum width of the hole in the spacer is in the range of 0.5 mm to 5.1 mm.

6. The tire according to any one of claims 2 to 5, characterized in that the shape of the hole in the spacer is hexagonal.

7. The material constituting the spacer has an elastic modulus of 1 × 10 6 Pa ~ 1 x 10 10 It is in the Pa range and has a surface free energy of 25 mJ / m 2 ~70 mJ / m 2 A tire according to any one of claims 2 to 6, characterized in that it is within the range.

8. The tire according to claim 1, characterized in that the spacer consists of granular additives.

9. Thickness T of the spacer M A tire according to any one of claims 1 to 8, characterized in that the diameter is in the range of 0.2 mm to 1.5 mm.

10. The thickness T of the adhesive directly below the central region of the container A and the thickness T of the spacer M satisfy the relationship of 1.0 ≤ T A / T M ≤ 2.0, and the tire according to any one of claims 1 to 9 is characterized in that.

11. The storage modulus of the adhesive at -40°C is 5.0 × 10⁻⁶. 8 Pa ~ 1.0 × 10 10 The pressure is in the range of Pa, and the storage modulus of the adhesive at 150°C is 1.0 × 10⁻⁶. 6 Pa ~ 5.0 x 10 7 A tire according to any one of claims 1 to 10, characterized in that it is within the range of Pa.

12. The tire according to any one of claims 1 to 11, wherein the housing has a bottom fixed to the inner surface of the tire, a side wall protruding from the bottom, a housing formed by the bottom and the side wall, and an opening communicating with the housing, and the angle of inclination of the side wall with respect to the bottom, measured on the outer wall side of the side wall when the functional component is housed in the housing, is smaller than the angle of inclination of the side wall with respect to the bottom, measured on the outer wall side of the side wall when the functional component is not housed in the housing, and the angle difference is in the range of 5° to 15°.

13. The tire according to claim 12, characterized in that the angle of inclination of the side wall portion with respect to the bottom portion, measured on the outer wall side of the side wall portion when the functional component is housed in the housing portion, is 90° or more.

14. The width of the opening is narrower than the minimum width of the housing, and the circumference D2 of the upper part of the housing u and the circumference D1 of the upper part of the functional component u Toga 0.60 ≤ D2 u / D1 u The tire according to claim 12 or 13, characterized in that it satisfies the relationship ≤ 0.

95.

15. The tire according to any one of claims 1 to 14, characterized in that the modulus of the housing when fully stretched at 20°C is 0.5 MPa or more and less than 10.0 MPa, and the loss modulus of the housing at 60°C is 0.4 MPa or more and less than 20.0 MPa.

16. The tire according to any one of claims 1 to 15, characterized in that the housing is made of vulcanized rubber.

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