Tire

Abstract

The invention provides a tire capable of improving high-speed durability of a functional component and preventing damage of a container. In a tire provided with a functional member (20) having a sensor function for detecting tire information, and a housing body (30) housing the functional member (20), the housing body (30) has a housing part (33) for housing the functional member (20), an opening part (34) communicating with the housing part (33) and allowing the functional member (20) to enter and exit, and a side wall part (32) surrounding the housing part (33). At least the side wall portion (32) is configured from an elastic material, and the volume Vs [cm3] of the functional member (20), the volume Vc [cm3] of the housing portion (33) when no load is applied, and the modulus M50 [MPa] of the elastic material at 50% elongation as measured in accordance with JIS K6251 satisfy the relationship 0.8 < = Vs / Vc * M50 < = 3.0.

Description

Technical Field

[0001] The present invention relates to a tire having a functional component with a sensor function for detecting tire information, and more specifically, to a tire that can improve the high-speed durability of the functional component while preventing damage to the housing. Background Technology

[0002] A common practice involves installing a functional component (e.g., a sensor unit including sensors) on the inner surface of the tire to acquire internal tire information such as internal pressure and temperature (see, for example, Patent Documents 1 and 2). When installing the functional component, a container made of rubber or the like is adhered to the inner surface of the tire, and the functional component is housed inside this adhered container. However, if the volume of the container is too large for the functional component, the container's fixation to the functional component is loose, leading to problems such as increased heat generation due to friction between the container and the functional component during high-speed driving, potentially causing damage to the container or the functional component. On the other hand, if the volume of the container is too small for the functional component, the container may deform excessively during long-distance driving, resulting in cracks.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6272225

[0006] Patent Document 2: Japanese Patent Publication No. 2016-505438 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The purpose of this invention is to provide a tire that can improve the high-speed durability of functional components while preventing damage to the housing.

[0009] means for solving problems

[0010] The tire of the present invention for achieving the above-mentioned objective comprises a functional component having a sensor function for detecting tire information, and a housing containing the functional component. The housing is characterized in that it has a receiving portion for receiving the functional component, an opening communicating with the receiving portion for allowing the functional component to enter and exit, and a sidewall portion surrounding the receiving portion. At least the sidewall portion is made of an elastic material, and the volume Vs of the functional component [cm²] 3 The volume Vc [cm³] of the housing when unloaded. 3 [and the modulus M of the elastic material at 50% elongation, as determined by JIS K6251]50 [MPa] satisfies 0.8≤Vs / Vc×M 50 Relationships ≤3.0.

[0011] Invention Effects

[0012] In this invention, the housing has a housing portion for housing a functional component, an opening communicating with the housing portion for the functional component to enter and exit, and sidewalls surrounding the housing portion. At least the sidewalls are made of an elastic material. The volume Vs of the functional component [cm²] 3 The volume of the containment section when unloaded, Vc [cm²] 3 [and the modulus M of elastic materials at 50% elongation, as determined by JIS K6251] 50 [MPa] satisfies 0.8≤Vs / Vc×M 50 The relationship ≤3.0 allows for the suppression of functional component vibration, prevention of heat generation caused by friction between the housing and the functional component, and suppression of housing deformation when the functional component is housed within the housing. This improves the crack resistance of the housing. Consequently, it is possible to improve the high-speed durability of the functional component while preventing damage to the housing.

[0013] In this invention, the volume Vs1 of the upper half of the functional component when it is divided at the midpoint of the height hs from the bottom surface to the top surface of the functional component, and the volume Vc1 of the upper half of the receiving portion when it is divided at the midpoint of the height hc of the receiving portion, preferably satisfy the relationship 1.0 ≤ Vs1 / Vc1 ≤ 1.8. Since the size of the upper half of the functional component contributes significantly to improving high-speed durability, by appropriately setting the ratio Vs1 / Vc1, the tightness provided by the sidewall portion can be enhanced, the vibration of the functional component can be suppressed, and the high-speed durability of the functional component can be effectively improved.

[0014] When the functional component is divided at a height hs from the bottom surface to the top surface, the volume Vs2 of the lower half of the functional component and the volume Vc2 of the lower half of the receiving portion when the receiving portion is divided at a height hc are preferably such that 0.8 ≤ Vs2 / Vc2 ≤ 1.3. By appropriately setting this ratio Vs2 / Vc2, root deformation of the sidewall portion can be suppressed, effectively improving the crack resistance of the receiving body.

[0015] The volume Vs of the functional component and the volume Vc of the housing preferably satisfy the relationship 1.0 ≤ Vs / Vc ≤ 1.5. This allows for a balanced improvement in the high-speed durability of the functional component and the crack resistance of the housing.

[0016] The width of the opening is narrower than the minimum width of the receiving section, and the perimeter Ds of the upper part of the functional component is... uThe perimeter Dc of the upper part of the containment section u Preferably, 0.60 ≤ Dc u / Ds u The relationship is ≤0.95. Therefore, the constraint force of the containment on the functional components can be increased, and the vibration of the functional components can be suppressed, thus preventing damage to the functional components during high-speed travel. Furthermore, since a good balance is achieved between the constraint force of the containment on the functional components and the degree of deformation that will not cause damage to the containment, damage to the containment can also be prevented.

[0017] The height hs from the bottom surface to the top surface of the functional component and the height hc of the housing preferably satisfy the relationship 0.85 ≤ hc / hs ≤ 0.98. This achieves a good balance between the constraint force of the housing on the functional component and the degree of deformation that will not damage the housing, thereby improving the durability of the functional component during high-speed driving.

[0018] In this invention, the housing is preferably fixed to the back of the tread portion. The housing is preferably fixed to the back of the tread portion using an adhesive. The housing is preferably made of one or more vulcanized rubbers. Using this housing also achieves the aforementioned excellent effects.

[0019] Furthermore, the functional component preferably has a sensor function obtained by using a piezoelectric element as a sensor element. When using such a functional component with a sensor function obtained by using a piezoelectric element, significant effects can be obtained.

[0020] The tire of the present invention is preferably a pneumatic tire, but it can also be a non-pneumatic tire. When it is a pneumatic tire, its interior can be filled with air, nitrogen, or other inert gases. Attached Figure Description

[0021] Figure 1 This is a meridional sectional view showing an inflatable tire constructed according to an embodiment of the present invention.

[0022] Figure 2 It means Figure 1 A top view of the arrangement of functional components in an inflatable tire.

[0023] Figure 3 yes Figure 2 The cross-sectional view of arrow III-III.

[0024] Figure 4 It is a three-dimensional diagram showing the functional components and their housings.

[0025] Figure 5 It is a cross-sectional view showing the functional components and their housings.

[0026] Figure 6It is a half-sectional view of the housing used to illustrate the dimensions of the functional components and the housing.

[0027] Figure 7 It is a cross-sectional view showing a modified example of the cross-sectional shape of a functional component. Detailed Implementation

[0028] Hereinafter, the structure of the present invention will be described in detail with reference to the accompanying drawings. Figures 1 to 5 This is a diagram showing an inflatable tire constructed according to an embodiment of the present invention.

[0029] like Figure 1 As shown, the pneumatic tire of this embodiment includes a tread portion 1 extending in the circumferential direction of the tire and formed in an annular shape, a pair of sidewall portions 2, 2 disposed on both sides of the tread portion 1, and a pair of bead portions 3, 3 disposed on the radially inner side of these sidewall portions 2.

[0030] A carcass layer 4 is provided between a pair of bead portions 3, 3. The carcass layer 4 comprises multiple reinforcing cords extending radially along the tire and folded back from the inside to the outside of the tire around the bead core 5 disposed in each bead portion 3. The carcass layer 4 includes: a main body portion 4A, which extends from the tread portion 1 through each sidewall portion 2 to each bead portion 3; and a rolled-up portion 4B, which is rolled up in each bead portion 3 around the bead core 5 and extends toward each sidewall portion 2. A sidewall core 6 with a triangular cross-section, made of a rubber composition, is disposed on the outer periphery of the bead core 5.

[0031] On the other hand, multiple belt layers 7 are embedded on the outer periphery of the carcass layer 4 in the tread portion 1. These belt layers 7 contain multiple reinforcing cords inclined relative to the tire circumference, and the reinforcing cords are arranged in a crisscrossing manner between the layers. In the belt layer 7, the inclination angle of the reinforcing cords relative to the tire circumference is set, for example, in the range of 10° to 40°. Steel cords are preferably used as the reinforcing cords of the belt layer 7. To improve high-speed durability, at least one cover layer 8 is disposed on the outer periphery of the belt layer 7, consisting of reinforcing cords arranged at an angle of, for example, 5° or less relative to the tire circumference. Organic fiber cords such as nylon and aramid are preferably used as the reinforcing cords of the cover layer 8.

[0032] It should be noted that the above description of the internal structure of a tire shows a representative example of a pneumatic tire, but is not limited to this.

[0033] In the aforementioned pneumatic tires, such as Figure 1 As shown, a cylindrical functional component 20 with a sensor function for detecting tire information is provided on the back of the tread portion 1.

[0034] like Figures 2-4As shown, the functional component 20 is housed inside the housing 30. The housing 30 has a flat bottom 31 fixed to the back of the tread portion 1, a cylindrical sidewall portion 32 protruding from the bottom 31, a housing portion 33 formed by the bottom 31 and the sidewall portion 32, and an opening 34 communicating with the housing portion 33 for the functional component 20 to enter and exit. The sidewall portion 32 surrounds the housing portion 33. The housing 30 can be a molded body made of one type of vulcanized rubber or a molded body made of multiple types of vulcanized rubber. The housing 30 thus constructed is fixed to the back of the tread portion 1, for example, by an adhesive, and the functional component 20 is housed within the housing 30. The functional component 20 has a contact surface 21 that contacts the back side of the tread portion 1. That is, the contact surface 21 is the surface that contacts the bottom 31 of the housing 30.

[0035] The functional component 20 has a structure that houses various electronic components within a housing. These electronic components may include various sensors, transmitters, receivers, control circuits, and batteries for acquiring tire information. Examples of tire information acquired through sensors include the internal temperature, internal pressure, and tread wear of a pneumatic tire. For instance, a temperature sensor or a pressure sensor may be used to measure the internal temperature or internal pressure. When detecting tread wear, for example, a sensor element 22 composed of a piezoelectric element may be disposed on the contact surface 21 of the functional component 20. This sensor element 22 detects an output voltage corresponding to the tire deformation during driving, and the wear of the tread 1 is detected based on this output voltage. Alternatively, an acceleration sensor or a magnetic sensor may be used.

[0036] In the aforementioned pneumatic tire, at least the sidewall portion 32 of the components constituting the housing 30 is made of an elastic material. Examples of elastic materials include rubber and elastomers. Furthermore, the volume Vs [cm²] of the functional component 20... 3 ], Volume Vc [cm³] of the containment section 33 when unloaded 3 [and the modulus M of elastic materials at 50% elongation] 50 [MPa] satisfies 0.8≤Vs / Vc×M 50 The relationship is ≤3.0. It is particularly preferred to satisfy 1.0≤Vs / Vc×M. 50 Relationships ≤2.0.

[0037] Here, the volume Vs of functional component 20 includes the volume of the housing thickness portion, and is the volume within the height hs of functional component 20 (and...). Figure 5The volume corresponding to the area of ​​the diagonal portion of the functional component 20. The height hs of the functional component 20 is measured with the functional component 20 housed in the housing 30, and is the height of the portion of the functional component 20 housed within the housing 33. This means that, for example, sometimes a gripper is provided on the upper part of the functional component 20 to facilitate gripping, but in the housed state, when the gripper extends out of the housing 33, the height hs of the functional component 20 does not include the height of the gripper portion outside the housing 33. On the other hand, the volume Vc of the housing 33 does not include the volume of the thickness portion of the opening 34, and is the volume within the height hc of the housing 33 (compared to the volume of the opening 34). Figure 5 The volume corresponding to the area of ​​the diagonal portion of the receiving part 33). The height hc of the receiving part 33 is measured in the state where the functional component 20 is not housed in the receiving body 30, and is the total inner height from the upper surface of the bottom 31 to the lower surface of the locking part 32e that bends towards the opening 34 in the side wall part 32.

[0038] In addition, the modulus M of elastic materials at 50% elongation 50 Preferably, the pressure is in the range of 0.5 MPa to 4.0 MPa, more preferably in the range of 0.8 MPa to 2.0 MPa. In this invention, the modulus M of the elastic material at 50% elongation is... 50 The determination was performed according to JIS K6251.

[0039] In the aforementioned pneumatic tire, the housing 30 has a housing portion 33 for housing the functional component 20, an opening 34 communicating with the housing portion 33 for allowing the functional component 20 to enter and exit, and a side wall portion 32 surrounding the housing portion 33. At least the side wall portion 32 is made of an elastic material. The volume Vs of the functional component 20 [cm] 3 ], Volume Vc [cm³] of the containment section 33 when unloaded 3 [and the modulus M of elastic materials at 50% elongation] 50 [MPa] satisfies 0.8≤Vs / Vc×M 50 The relationship ≤3.0 allows for the suppression of vibration of the functional component 20 when it is housed within the housing 30, preventing heat generation caused by friction between the housing 30 and the functional component 20, suppressing deformation of the housing 30, and improving the crack resistance of the housing 30. Thus, it is possible to improve the high-speed durability of the functional component 20 while preventing damage to the housing 30.

[0040] Here, in Vs / Vc×M 50When the calculated value is less than 0.8, the functional component 20 becomes loosely secured within the housing 30 when housed within it. Therefore, during high-speed travel, the functional component 20 may move within the housing 30, leading to increased heat generation due to friction between the housing 30 and the functional component 20, making either the housing 30 or the functional component 20 susceptible to damage. Conversely, when Vs / Vc×M... 50 When the calculated value exceeds 3.0, the functional component 20 is housed in the housing 30, and the housing 30 becomes tightly fixed to the functional component 20. Therefore, the housing 30 will deform excessively during long-distance travel, and the housing 30 is prone to cracking.

[0041] In the aforementioned pneumatic tires, such as Figure 5 As shown, when the functional component 20 is divided at the midpoint Ps (the height position from the bottom surface to 0.5×hs) of the height hs from the bottom surface to the top surface of the functional component 20, the volume Vs1 of the upper half of the functional component 20 is [cm]. 3 The volume Vc1 of the upper half of the housing section 33 when it is divided at the midpoint Pc (the height from the bottom surface to 0.5×hc) of the housing section 33. 3 Preferably, the relationship 1.0 ≤ Vs1 / Vc1 ≤ 1.8 is satisfied. Since the size of the upper part of the functional component 20 contributes significantly to improving high-speed durability, by setting the ratio Vs1 / Vc1 in this way, the fastening provided by the side wall portion 32 can be enhanced, the vibration of the functional component 20 can be suppressed, and the high-speed durability of the functional component 20 can be effectively improved.

[0042] Furthermore, when the functional component 20 is divided at the midpoint Ps of its height hs, the volume Vs2 [cm] of the lower half of the functional component 20 is... 3 The volume Vc2 of the lower half of the containment section 33 when it is divided at the midpoint Pc of the height hc of the containment section 33. 3 Preferably, the relationship 0.8 ≤ Vs2 / Vc2 ≤ 1.3 is satisfied. By setting the ratio Vs2 / Vc2 appropriately, the root deformation of the sidewall portion 32 can be suppressed, effectively improving the crack resistance of the housing 30.

[0043] Furthermore, the volume Vs of the functional component 20 and the volume Vc of the housing 33 preferably satisfy the relationship 1.0 ≤ Vs / Vc ≤ 1.5. That is, the aim is to improve the restraint of the housing 30 by setting the volume Vs of the functional component 20 relatively large within a specific range relative to the volume Vc of the housing 33. By setting the ratio Vs / Vc appropriately in this way, the high-speed durability of the functional component 20 and the crack resistance of the housing 30 can be improved in a balanced way.

[0044] In the aforementioned pneumatic tire, the width w1 of the opening 34 (refer to...) Figure 3 ) than the minimum width w2 of the containment section 33 (refer to Figure 3 Narrow, the perimeter Ds of the upper part of the functional component 20 u The perimeter Dc of the upper part of the containment section 33 u Preferably, 0.60 ≤ Dc u / Ds u A relationship ≤0.95. That is, the intention is to measure the perimeter Dc of the upper portion of the housing 33. u The perimeter Ds relative to the upper part of the functional component 20 u The perimeter Dc of the upper portion of the containment section 33 is set relatively small within a specific range to enhance the restraint of the containment body 30. u Obtained in the following manner: Figure 6 As shown, in the state before housing the functional component 20, the height of the housing 33 is defined as h1, which is 3 / 4 (0.75 × hc) of its height hc. The perimeter of the housing 33 is measured at three locations: the position at height h1 and a position equivalent to ±25% (0.25 × h1) of height h1. The perimeters measured at these three locations are then averaged. Additionally, the perimeter Ds of the upper portion of the functional component 20 is also measured. u The perimeter of the functional component 20 is obtained by measuring the perimeter of the functional component 20 at the positions corresponding to the three positions mentioned above, and averaging the perimeters measured at these three positions.

[0045] By setting the perimeter Ds of the functional component 20 in this way... u and the perimeter Dc of containment section 33 u This increases the constraint force of the housing 30 on the functional component 20, suppresses the vibration of the functional component 20, and thus prevents the functional component 20 from breaking during high-speed travel. Furthermore, since a good balance is achieved between the constraint force of the housing 30 on the functional component 20 and the degree of deformation that will not cause damage to the housing 30, damage to the housing 30 can also be prevented.

[0046] Here, if the ratio Dc u / Ds u If the ratio Dc is less than 0.60, the restraining force generated by the containment body 30 will increase, but the deformation of the side wall 32 will also increase. Therefore, the containment body 30 may crack during long-distance travel, increasing the likelihood of damage to the containment body 30. Conversely, if the ratio Dc... u / Ds uIf the value exceeds 0.95, the constraint force generated by the containment body 30 will decrease, and the vibration of the functional component 20 within the containment body 30 will increase. Therefore, the friction between the containment body 30 and the functional component 20 will lead to increased heat generation, which in turn will cause the functional component 20 to break.

[0047] Furthermore, it is preferable that the height hs of the functional component 20 and the height hc of the receiving portion 33 satisfy the relationship of 0.85 ≤ hc / hs ≤ 0.98. By appropriately setting the height hs of the functional component 20 and the height hc of the receiving portion 33, a good balance is achieved between the restraining force of the receiving body 30 on the functional component 20 and the degree of deformation that will not cause damage to the receiving body 30, thereby improving the durability of the functional component 20 during high-speed driving.

[0048] Here, if the ratio hc / hs is less than 0.85, the locking portion 32e of the side wall portion 32 cannot accommodate the functional component 20 in a way that covers it, thus reducing the effect of improving the durability of the functional component 20 during high-speed driving. Conversely, if the ratio hc / hs is greater than 0.98, the restraint of the housing 30 will be weaker, and the vibration of the functional component 20 within the housing 30 will be greater, thus failing to achieve the effect of improving the durability of the functional component 20 during high-speed driving.

[0049] In this invention, the volume Vs of the functional component 20, the volume Vc of the housing 30, and the modulus M are... 50 The shape of functional component 20 is not particularly limited, except for various dimensions that satisfy specific relationships. Figure 5 Besides the generally rectangular cross-sectional shape shown, other examples include: Figure 7 (a) shows a stepped cross-sectional shape where the upper half of the functional component 20 is narrower than the lower half, as illustrated. Figure 7 (b) shows a stepped cross-sectional shape where the upper half of the functional component 20 is wider than the lower half, as indicated. Figure 7 (c) shows a cross-sectional shape where the width gradually decreases towards the lower part of the functional component 20, as shown in the figure. Figure 7 As shown in (d), the width of the cross-section gradually decreases towards the top and bottom from the middle position of the height of the functional component 20.

[0050] Example

[0051] Tires for Comparative Examples 1 and 2 and Examples 1 to 12 were manufactured, with a tire size of 225 / 45R18. Each tire included a functional component with a sensor function for detecting tire information and a housing containing the functional component. The functional component had a sensor function obtained using a piezoelectric element as the sensor element. The volume Vs of the functional component, the volume Vc of the housing, and the modulus M were set as shown in Table 1. 50Vs / Vc×M 50 The volume of the functional component Vs1, the volume of the receiving part Vc1, the ratio Vs1 / Vc1, the volume of the functional component Vs2, the volume of the receiving part Vc2, the ratio Vs2 / Vc2, the ratio Vs / Vc, and the ratio Dc. u / Ds u The ratio hc / hs. It should be noted that the functional components are mounted on the back of the tread via a housing made of vulcanized rubber, and the housing is fixed to the inner surface of the tire using an adhesive.

[0052] The high-speed durability of the functional components and the crack resistance of the housing were evaluated using the following test methods, and the results are shown in Table 1.

[0053] High-speed durability (functional components):

[0054] Each test tire was assembled onto a wheel with a rim size of 18×7.5, subjected to a load of 88% of its maximum load capacity, and subjected to a driving test using a drum tester at an air pressure of 360 kPa. Specifically, starting from an initial speed of 120 km / h, the speed was increased by 10 km / h every 10 minutes, and the maximum speed at which the functional components operated normally was measured. The evaluation results are expressed as an index with the measured value of Comparative Example 1 set as 100. The higher the index value, the better the high-speed durability.

[0055] Crack resistance (container):

[0056] Each test tire was assembled onto a wheel with a rim size of 18×7.5. After 5 days of deterioration treatment at 80°C in an oxygen atmosphere, it was subjected to a load of 80% of its maximum load capacity and a driving test was conducted using a drum tester under an air pressure of 250 kPa. Specifically, starting from an initial speed of 120 km / h, the speed was increased by 10 km / h every 24 hours until a speed of 170 km / h was reached. The presence of cracks or wrinkles in the containment was then visually inspected. The evaluation results were expressed in four levels: "◎ (Excellent)" indicates no cracks or wrinkles, "○ (Good)" indicates wrinkles less than 1 mm in length, "Δ (Acceptable)" indicates wrinkles longer than 1 mm but less than 5 mm in length, and "× (Unacceptable)" indicates cracks.

[0057] [Table 1]

[0058]

[0059] As can be seen from Table 1, the tires of Examples 1 to 12 showed improved high-speed durability of functional components and crack resistance of the housing compared to the comparative examples.

[0060] Comparative Example 2 was set to be greater than Vs / Vc×M as specified in this invention. 50 The upper limit of the numerical range is used, so although the high-speed durability of the functional components is improved, the improvement effect of the crack resistance of the containment cannot be fully obtained.

[0061] Explanation of reference numerals in the attached figures

[0062] 1: Fetal face

[0063] 2: Side wall portion

[0064] 3: Bead area

[0065] 20: Functional components

[0066] 21: Contact surface

[0067] 22: Sensor Components

[0068] 30: Containment Entity

[0069] 31: Bottom

[0070] 32: Side wall portion

[0071] 33: Containment Department

[0072] 34: Opening

Claims

1. A tire, comprising: a functional member having a sensor function of detecting tire information; and a housing member housing the functional member, characterized in that The housing has a housing portion for housing the functional member, an opening portion communicating with the housing portion for allowing the functional member to enter and exit, and a side wall portion surrounding the housing portion. At least the side wall portion is made of an elastic material. The functional member has a volume Vs [cm 3 ], the housing portion has a volume Vc [cm 3 ] under no load, and the elastic material has a modulus M 50 [MPa] at 50% elongation determined based on JIS K6251. The relationship 0.8 ≤ Vs / Vc × M 50 ≤ 3.0 is satisfied.

2. Tyre according to Claim 1, characterized in that, a volume Vs1 of an upper half of the functional member when the functional member is divided at a middle position of a height hs from a bottom surface to an upper surface of the functional member satisfies a relationship of 1.0 ≤ Vs1 / Vc1 ≤ 1.8 with a volume Vc1 of an upper half of the housing member when the housing member is divided at a middle position of a height hc of the housing member.

3. Tyre according to Claim 1 or 2, characterised in that, a volume Vs2 of a lower half of the functional member when the functional member is divided at the middle position of the height hs from the bottom surface to the upper surface of the functional member satisfies a relationship of 0.8 ≤ Vs2 / Vc2 ≤ 1.3 with a volume Vc2 of a lower half of the housing member when the housing member is divided at the middle position of the height hc of the housing member.

4. Tyre according to any one of claims 1 to 3, characterised in that, a volume Vs of the functional member satisfies a relationship of 1.0 ≤ Vs / Vc ≤ 1.5 with a volume Vc of the housing member.

5. Tyre according to any one of claims 1 to 4, characterized in that, The width of the opening portion is narrower than the minimum width of the housing portion, and the circumference Dsof the upper side portion of the functional component u The circumference Dcof the upper side portion of the housing portion u The relationship 0.60 ≤ Dc u / Ds u ≤ 0.95 is satisfied.

6. A tyre according to any one of claims 1 to 5, characterised in that, a height hs from a bottom surface to an upper surface of the functional member satisfies a relationship of 0.85 ≤ hc / hs ≤ 0.98 with a height hc of the housing member.

7. A tyre according to any one of claims 1 to 6, characterised in that, the housing member is fixed to a back surface of a tread portion.

8. A tyre according to any one of claims 1 to 7, characterised in that, the housing member is fixed to the back surface of the tread portion by an adhesive.

9. A tyre according to any one of claims 1 to 8, characterised in that, the housing member is composed of one or more vulcanized rubbers.

10. A tyre according to any one of claims 1 to 9, characterised in that, the functional member has the sensor function obtained using a piezoelectric element as a sensor element.

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