Patent Application
20250196547
The present technology relates to a functional component assembly including a functional component having a function of detecting a state of a tire, and a support body thereof, and a tire including the functional component assembly.
In recent years, a sensor unit (functional component) including a sensor for acquiring tire internal information, such as internal pressure or temperature, has been installed in a tire cavity. In order to attach such a functional component to a tire inner surface, a support body that functions as a pedestal of the functional component is bonded to the tire inner surface, and the functional component is stored inside the support body (for example, see Japan Unexamined Patent Publication No. 2015-160512 A). However, if the functional component is not sufficiently held by the support body, the functional component may fall off or be damaged by an impact or the like during travel.
The present technology provides a functional component assembly that makes it possible to prevent a functional component from falling off and provide improved damage resistance, and a tire including the functional component assembly.
An embodiment of the present technology provides a functional component assembly including: a functional component having a function of detecting a state of a tire; and a support body configured to accommodate the functional component and attached to a tire inner surface, in which the support body includes a base portion having a sheet shape and a housing portion having a side wall protruding from one surface of the base portion and configured to accommodate at least a part of the functional component, an other surface of the base portion being an attachment surface to the tire inner surface, the functional component is fixed inside the housing portion via a locking portion, the locking portion is configured by a pair composed of a protrusion portion that is provided on one of the side wall of the housing portion or a portion of the functional component in contact with the side wall and that protrudes toward the other of the side wall of the housing portion or the portion of the functional component in contact with the side wall and a receiving portion that is provided on the other of the side wall of the housing portion or the portion of the functional component in contact with the side wall and that is configured to be in contact with the protrusion portion, and contact of the protrusion portion with the receiving portion fixes the functional component inside the housing portion, and in a state where the functional component is not accommodated in the support body, when a height of the locking portion on the support body side from a lower end of the side wall is H and a height of the locking portion on the functional component side from a bottom surface is h, the heights H and h satisfy a relationship 1.00<h/H≤1.40.
In an embodiment of the present technology, since the locking portion configured by a pair composed of the protrusion portion and the receiving portion is provided on the side wall of the housing portion and the portion of the functional component in contact with the side wall, and the functional component is fixed inside the housing portion by contact of the protrusion portion with the receiving portion, it is possible to suppress movement of the functional component in a vertical direction with respect to the tire inner surface. In addition, since the height H of the locking portion on the support body side and the height h of the locking portion on the functional component side satisfy the above-described relationship, the functional component is pressed toward the tire inner surface side when the protrusion portion and the receiving portion come into contact with each other, making it possible to effectively prevent the functional component from falling off and to improve the damage resistance.
In an embodiment of the present technology, in a state where the functional component is accommodated in the support body, when a height of the locking portion on the support body side from the lower end of the side wall is H′ and a maximum thickness of the functional component is T, H′ and T preferably satisfy relationships 5.0 mm≤T≤30.0 mm and 0.30≤H′/T≤1.00. Such dimensions are advantageous for preventing the functional component from falling off and improving the damage resistance. In particular, when the maximum thickness T of the functional component is within the above-described range, it is possible to suppress a load applied to the side wall of the housing portion when the functional component is accommodated. In addition, when the ratio H′/T is within the above-described range, it is possible to effectively prevent the functional component from falling off.
In an embodiment of the present technology, when a maximum length of the functional component in a horizontal direction is L, a protruding amount of the protrusion portion is LH, and a thickness of the protrusion portion is LV, L, LH, and LV preferably satisfy relationships 5.0 mm≤L≤35.0 mm, 0.04≤LH/L≤0.40, and 0.10≤LH/LV≤3.00. With such dimensions, the fitting protrusion portion has an appropriate size, which is advantageous for preventing the functional component from falling off and improving the damage resistance.
In an embodiment of the present technology, preferably, an outer shape of the functional component is a columnar shape, the housing portion has a cylindrical shape corresponding to the functional component, and a sum of projection lengths of the locking portion on a circumference of the side wall is ¾ times to 1 time a circumferential length of the side wall. In an aspect in which the outer shape of the functional component is a columnar shape and the housing portion has a cylindrical shape corresponding to the functional component, securing the length of the locking portion on the circumference of the side wall as described above is advantageous for preventing the functional component from falling off and improving the damage resistance.
In an embodiment of the present technology, a plurality of locking portions may be provided along a height direction of the side wall of the housing portion and a height direction of the functional component. According to this configuration, since the functional component is fixed to the housing portion by each of the plurality of locking portions, it is possible to more firmly fix the functional component, which is advantageous for preventing the functional component from falling off and improving the damage resistance.
In an embodiment of the present technology, an outer shape of the functional component may be a columnar shape, the housing portion may have a cylindrical shape corresponding to the functional component, and the locking portion may be provided in a spiral shape. According to this configuration, since the spiral locking portion substantially functions as a screw, the functional component can be fixed to the housing portion by being rotated, and thus the functional component can be fixed more firmly and stably.
In an embodiment of the present technology, the functional component may include a sensor configured to acquire tire information, and the sensor may include a piezoelectric element. According to this configuration, when the functional component is pressed toward the tire inner surface side as described above, vibration or the like can be more accurately detected.
In an embodiment of the present technology, an elongation at break EB of rubber constituting the support body preferably ranges from 50% to 900%, and a modulus at 300% elongation of the rubber constituting the support body preferably ranges from 2 MPa to 16 MPa. As a result, it is possible to improve the workability when inserting the functional component into the support body (housing portion), the holding property of the support body, and the breaking resistance of the support body in a well-balanced manner. Note that the elongation at break and the modulus at 300% elongation of the rubber constituting the support body are measured in conformity to JIS (Japanese Industrial Standard)-K6251.
The functional component assembly of an embodiment of the present technology is used attached to a tire inner surface. A tire including the functional component assembly of an embodiment of the present technology attached to the tire inner surface (hereinafter, referred to as “tire of an embodiment of the present technology”) can effectively prevent the functional component from falling off and provide improved damage resistance by the above-described characteristics of the functional component assembly of an embodiment of the present technology. Note that the tire according to an embodiment of the present technology is preferably a pneumatic tire, but may be a non-pneumatic tire. In the case of a pneumatic tire, the inside thereof may be filled with air, an inert gas such as nitrogen, or other gases.
In the tire of an embodiment of the present technology, preferably, the functional component includes a sensor configured to acquire tire information, and a shortest distance between the sensor and the tire inner surface is equal to or less than 5 mm. By bringing the sensor close to the tire inner surface in this way, the tire information can be easily acquired. However, by using the functional component assembly of an embodiment of the present technology described above, the sensor can be more firmly and stably fixed at a suitable position close to the tire inner surface.
In the tire of an embodiment of the present technology, the support body may be fixed to the tire inner surface, while the functional component may be detachable from the support body. With this configuration, it is possible to replace only the functional component accommodated in the support body while leaving the support body on the tire inner surface, which is advantageous for reducing costs.
In the tire of an embodiment of the present technology, the support body may be fixed to the tire inner surface via an adhesive layer. In addition, in the tire of an embodiment of the present technology, the tire information about the tire to which the functional component assembly is attached may be periodically and automatically transmitted.
Configurations of embodiments of the present technology will be described in detail below with reference to the accompanying drawings.
For example, as illustrated in
A carcass layer 4 including a plurality of reinforcing cords (hereinafter, referred to as carcass cords) extending in the tire radial direction is mounted between the pair of bead portions 3 on the right and left. A bead core 5 is embedded in each of the bead portions, and a bead filler 6 having an approximately triangular cross-sectional shape is disposed on an outer circumference of the bead core 5. The carcass layer 4 is folded back around the bead core 5 from an inner side to an outer side in a tire width direction. Accordingly, the bead core 5 and the bead filler 6 are wrapped by a body portion (a portion extending from the tread portion 1 through each of the sidewall portions 2 to each of the bead portions 3) and a folded back portion (a portion folded back around the bead core 5 of each bead portion 3 and extending toward each sidewall portion 2 side) of the carcass layer 4.
A plurality of belt layers 7 (in the illustrated example, two layers) are embedded on an outer circumferential side of the carcass layer 4 in the tread portion 1. Each of the belt layers 7 includes a plurality of reinforcing cords (hereinafter, referred to as belt cords) inclined with respect to the tire circumferential direction, and the belt cords are disposed so as to intersect with one another between the layers. In the belt layers 7, an inclination angle of the belt cord with respect to the tire circumferential direction may be set within a range, for example, from 10° to 40°. For example, steel cords are preferably used as the belt cords constituting the belt layers 7.
In addition, a belt cover layer 8 is provided on the outer circumferential side of the belt layers 7. The belt cover layer 8 includes a reinforcing cord (hereinafter, referred to as a cover cord) oriented in the tire circumferential direction. In the belt cover layer 8, an angle of the cover cord with respect to the tire circumferential direction may be set to, for example, 0° to 5°. As the belt cover layer 8, a full cover layer 8a that covers an entire region of the belt layers 7 in the width direction, and a pair of edge cover layers 8b that locally cover both end portions of the belt layers 7 in the tire width direction can be provided individually or in combination (in the illustrated example, both of the full cover layer 8a and the edge cover layers 8b are provided). An organic fiber cord such as nylon or aramid is preferably used as the cover cord of the belt cover layer 8.
Since an embodiment of the present technology mainly relates to a functional component assembly 10, which will be described below, the basic structure of the tire on which the functional component assembly 10 is mounted is not limited to that described above.
In the example of
As illustrated in an enlarged view of
For example, as illustrated in
An outer shape of the functional component 20 (housing 21) is not particularly limited, but as illustrated in
The support body 30 accommodates the functional component 20. As illustrated in
Examples of the material of the support body 30 include chloroprene rubber (CR), butyl rubber (IIR), natural rubber (NR), acrylonitrile-butadiene copolymer rubber (NBR), butadiene rubber (BR), and styrene-butadiene rubber (SBR), and a single material or a blend of two or more materials can be used. Since these materials are excellent in adhesiveness to butyl rubber constituting the tire inner surface, when the support body 30 is formed of the above materials, sufficient adhesiveness between the support body 30 and the tire inner surface can be secured.
The physical properties of the rubber constituting the support body 30 are not particularly limited. However, from the perspective of the workability when inserting the functional component 20 into the support body 30 (housing portion 31), the holding property of the support body 30 for the functional component 20, the breaking resistance of the support body 30, and the like, an elongation at break EB is preferably 50% to 900%, and a modulus at 300% elongation is preferably 2 MPa to 16 MPa. With such physical properties, it is possible to improve the above-described characteristics (the workability when inserting the functional component 20 into the support body 30, the holding property of the support body for the functional component 20, and the breaking resistance of the support body 30) in a well-balanced manner.
In the example of
Since the support body 30 is attached to the tire inner surface, the support body is not necessarily required to have the contact surface 30B described above. That is, as illustrated in
The housing portion 31 of the support body 30 does not need to accommodate the entire functional component 20, and may accommodate at least a part of the functional component. For example, in the example of
The locking portion 40 provided on the functional component 20 and the support body 30 is configured by a pair composed of a protrusion portion 41 and a receiving portion 42, and the protrusion portion 41 is received by the receiving portion 42, thereby fixing the functional component 20 inside the housing portion 31. For example, in an aspect of
In addition to the locking portion 40 (combination of the fitting protrusion portion 41 and the fitting recess portion 42) as illustrated in
In a state where the functional component 20 is not accommodated in the support body 30 as illustrated in
Note that, as illustrated in the drawing, the height H is measured on the basis of a point, which is closest to the lower end of the side wall 30A, in the locking portion 40 on the support body 30 side. That is, when the support body 30 has the contact surface 30B (the case of
In a state where the functional component 20 is accommodated in the support body 30 as illustrated in
The dimensions of the locking portion 40 are not particularly limited, but as illustrated in
Note that the locking portion 40 (protrusion portion 41) does not need to protrude along the horizontal direction of the functional component 20, and as illustrated in
When the outer shape of the functional component 20 is a columnar shape and the housing portion 31 has a cylindrical shape corresponding to the functional component 20, as illustrated in
As illustrated in
When the outer shape of the functional component 20 is a columnar shape and the housing portion 31 has a cylindrical shape corresponding to the functional component 20, the locking portion 40 may be provided in a spiral shape as illustrated in
In the above description, the locking portion 40 is provided on the inner side of the housing portion 31 in any case. However, depending on the shape of the functional component 20 (housing 21), the locking portion 40 may be provided on an outer side of the housing portion 31. For example, in an aspect of
When the above-described functional component assembly is used, the functional component 20 can be firmly and stably fixed. Therefore, the sensor 23 included in the functional component 20 can be easily disposed at a position suitable for acquiring the tire information. For this reason, the shortest distance between the sensor 23 included in the functional component 20 and the tire inner surface is preferably set to be equal to or less than 5 mm, and more preferably equal to or less than 3 mm. By bringing the sensor 23 close to the tire inner surface in this way, the tire information can be easily acquired. However, by using the functional component assembly of an embodiment of the present technology described above, the sensor can be more easily and reliably disposed at a suitable position close to the tire inner surface.
When the above-described functional component assembly is used, since the locking portion 40 is locked by the combination of the protrusion portion 41 and the receiving portion 42, conversely, when this state is released, the functional component 20 can be removed from the support body 30. For example, in the case where the locking portion 40 is configured by the fitting protrusion portion 41 and the fitting recess portion 42, since the locking portion is locked by fitting the fitting protrusion portion 41 into the fitting recess portion 42, conversely, when this fitting state is released, the functional component 20 can be removed from the support body 30. Therefore, the support body 30 may be fixed to the tire inner surface while the functional component 20 may be detachable from the support body 30. According to this configuration, it is possible to replace only the functional component 20 accommodated in the support body 30 in a state where the support body is left on the tire inner surface, which is advantageous for reducing environmental load and cost.
The present technology will further be described below by way of Examples, but the scope of the present technology is not limited to the Examples.
Pneumatic tires (test tires) of Comparative Examples 1 and 2 and Examples 1 to 17 with a tire size of 275/40R21 and a basic structure illustrated in
The corresponding drawing numbers are described in the “shape of locking portion” columns in Tables 1 and 2. Example 3 is an example in which a plurality of locking portions are provided as illustrated in
These test tires were evaluated for fall-off resistance and damage resistance according to the following evaluation methods. The results thereof are shown in Tables 1 and 2.
Each test tire was mounted on a wheel having a rim size of 21×9.5 J and mounted on a drum tester having a drum diameter of 1707 mm, and in a state where the air pressure was 360 kPa and 88% of the maximum applied load was applied, the traveling speed was increased by 10 km/h every 10 minutes from a reference speed corresponding to the speed symbol of the tire, the presence or absence of fall-off of the functional component was checked for each speed, and the speed at the time when the fall-off occurred was measured. The evaluation results are expressed as index values with Standard Example 1 being defined as 100. Larger index values indicate higher speed at the time of fall-off, and superior fall-off resistance.
Each test tire was mounted on a wheel having a rim size of 21×9.5 J and mounted on a drum tester having a drum diameter of 1707 mm, and in a state where the air pressure was 360 kPa and 88% of the maximum applied load was applied, the traveling speed was increased by 10 km/h every 10 minutes from the reference speed corresponding to the speed symbol of the tire, the damaged state of the functional component assembly was checked for each speed, and the damage resistance was evaluated by comprehensively considering the speed at the time when the damage occurred and the damaged state of the functional component. The evaluation results are expressed as index values with Standard Example 1 being defined as 100. Larger index values indicate higher speed at the time of damage, smaller damage, and superior damage resistance.
As can be seen from Tables 1 and 2, in Examples 1 to 17, the fall-off resistance and the damage resistance were improved as compared with Standard Example 1. On the other hand, in Comparative Example 1, since the ratio h/H was smaller than 1, the effect of pressing the functional component against the tire inner surface was not obtained, and thus the fall-off resistance was deteriorated. In Comparative Example 2, since the ratio h/H was larger than 1, the effect of pressing the functional component against the tire inner surface was obtained, and thus the functional component was prevented from falling off. However, since the ratio h/H was too large, the damage resistance was deteriorated.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-050180 | Mar 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/010247 | 3/16/2023 | WO |
