Retreaded tire and method for manufacturing the same

Abstract

To provide a retreaded tire which can improve communication property of a transponder, and a method for manufacturing the same.SOLUTION: A retreaded tire includes a base tire 10 having a skeleton composed of a carcass layer 4 bridged between a pair of bead parts 3 and a plurality of reinforcement belt layers 7 arranged on the outer peripheral side of the carcass layer 4 in a tread part 1, and a tread rubber layer 30 arranged outside in a tire radial direction of the base tire 10, where a transponder 20 is arranged outside the skeleton of the base tire 10.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a retread tire having an embedded transponder and a manufacturing method thereof, and more particularly to a retread tire that enables improved communication performance of the transponder and a manufacturing method thereof. [Background technology]

[0002] BACKGROUND ART Used tires are re-used as retread tires by grinding off the tread and attaching a new tread rubber layer (see, for example, Patent Document 1).

[0003] Also, it has been proposed to embed an RFID tag (transponder) inside a pneumatic tire (see, for example, Patent Document 2). However, depending on the position where the transponder is embedded inside the green tire, there is a problem that the communication performance of the transponder may be deteriorated. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-76269 [Patent Document 2] Japanese Patent Application Publication No. 7-137510 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a retread tire and a manufacturing method thereof that enable improved communication performance of a transponder. [Means for solving the problem]

[0006] To achieve the above object, the retreaded tire of the present invention is characterized in that it comprises a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and multiple reinforcing belt layers arranged on the outer circumferential side of the carcass layer in the tread portion, and a tread rubber layer arranged radially outward of the base tire, wherein a transponder is arranged outside the skeleton of the base tire.

[0007] Furthermore, the method for manufacturing a retread tire of the present invention is characterized in that the tread portion of a used tire is ground to form a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and a plurality of reinforcing belt layers arranged on the outer circumferential side of the carcass layer in the tread portion, a transponder is arranged outside the skeleton of this base tire, and then the assembly of the base tire and a tread rubber layer arranged radially outward of the base tire is vulcanized. [Effects of the Invention]

[0008] In the present invention, in a retread tire including a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and multiple reinforcing belt layers arranged on the outer peripheral side of the carcass layer in the tread portion, and a tread rubber layer arranged radially outward of the base tire, a transponder is arranged outside the skeleton of the base tire, and since the transponder is arranged in a position close to the outer surface of the tire, communication performance of the transponder can be improved. Furthermore, even if a transponder already arranged in a tire fails during the first run, it is possible to replace the transponder, and traceability management can be easily performed during the second run.

[0009] In the retread tire of the present invention, the transponder is preferably disposed between the base tire and the tread rubber layer, which is preferable because the transponder can be easily disposed during the retread tire manufacturing process and does not deteriorate the yield.

[0010] The transponder is preferably disposed on the outer side in the tire width direction of the end portion in the tire width direction of the widest reinforcement belt layer among the multiple reinforcement belt layers. Since metal members are often present in the tread portion and can be a factor in deteriorating the communication performance of the transponder or in causing damage to the transponder due to ground pressure, disposing the transponder away from the reinforcement belt layers can effectively improve the communication performance of the transponder.

[0011] The transponder is preferably arranged at a distance of 5 mm or more from an end in the tire width direction of the widest reinforcing belt layer among the multiple reinforcing belt layers, and at a distance of 5 mm or more from an end in the tire width direction of the tread rubber layer. By arranging the transponder at a distance from the end of the reinforcing belt layer and the end of the tread rubber layer, it is possible to improve the durability of the tire.

[0012] The transponder is preferably disposed in a side area of ​​the tire casing that is not covered by the tread rubber layer, thereby effectively improving the communication performance of the transponder.

[0013] The transponder is preferably embedded inside the sidewall rubber layer disposed on the outer side of the carcass layer in the tire width direction, whereby the transponder is disposed inside the base tire, thereby improving the durability of the transponder and effectively improving the communication performance of the transponder.

[0014] It is preferable that the transponder is covered with a covering layer. Furthermore, it is more preferable that the relative dielectric constant of the covering layer is lower than the relative dielectric constant of the rubber member adjacent to the covering layer. By covering the transponder with a covering layer in this way, the communication performance of the transponder can be effectively improved.

[0015] The thickness of the rubber on the reinforcing belt layer at the center of the tire base in the tire width direction is preferably 1 mm or more, which can effectively improve the durability of the tire.

[0016] The transponder is preferably embedded inside the tread rubber layer, which can effectively improve the durability of the tire. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a meridian cross-sectional view showing an example of a retread tire according to an embodiment of the present invention. [Figure 2] FIG. 10 is a meridian cross-sectional view showing a modified example of a retread tire according to an embodiment of the present invention. [Figure 3] FIG. 10 is a meridian cross-sectional view showing another modified example of a retread tire according to an embodiment of the present invention. [Figure 4] FIG. 10 is a meridian cross-sectional view showing another modified example of a retread tire according to an embodiment of the present invention. [Figure 5] 1A and 1B show an example of a transponder that can be embedded in a retread tire according to the present invention, where 1A is a perspective view and 1B is a cross-sectional view. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 shows a retread tire according to an embodiment of the present invention;

[0019] The base tire 10 is a member formed by grinding (buffing) a part of the tread portion and sidewall portion of a tire whose remaining grooves have reached the end of their life. The tread rubber layer 30 attached to this base tire 10 is a rubber member that constitutes the new tread portion 1 of the retread tire.

[0020] Furthermore, a retread tire generally comprises a tread portion 1 extending circumferentially around the tire to form a ring, a pair of sidewall portions 2 arranged on both sides of the tread portion 1, and a pair of bead portions 3 arranged radially inward of the sidewall portions 2.

[0021] At least one carcass layer 4 (one layer in FIG. 1) made up of a plurality of carcass cords arranged in the radial direction is mounted between a pair of bead portions 3. Metal cords such as steel cords are preferably used as the carcass cords making up the carcass layer 4. An annular bead core 5 is embedded in each bead portion 3, and a bead filler 6 made of a rubber composition and having a triangular cross section is disposed on the outer periphery of the bead core 5.

[0022] A plurality of reinforcing belt layers 7 (four layers in FIG. 1 ) are embedded on the tire radially outer side of the carcass layer 4 in the tread portion 1. Each reinforcing belt layer 7 includes a plurality of belt cords (e.g., steel cords) inclined with respect to the tire circumferential direction. These reinforcing belt layers 7 include two central reinforcing belt layers 72, 73 whose belt cords intersect with each other, and reinforcing belt layers 71, 74 disposed on the tire radially inner and outer sides of these reinforcing belt layers 72, 73. The inclination angle of the belt cords constituting the reinforcing belt layers 72, 73 with respect to the tire circumferential direction is set within a range of 15° to 35°, for example, and the inclination angle of the belt cords constituting the reinforcing belt layers 71, 74 with respect to the tire circumferential direction is set within a range of 15° to 75°, for example. Among the reinforcing belt layers 71 to 74, the reinforcing belt layer 72 is configured to have the widest width.

[0023] The base tire 10 has a residual tread rubber layer 11 that remains in the tread portion 1 so as to cover the reinforcing belt layer 7, a pair of sidewall rubber layers 12 that are arranged on the tire width direction outer sides of the carcass layer 4 in the left and right sidewall portions 2, and a pair of rim cushion rubber layers 13 that are arranged on the tire width direction outer sides of the bead cores 5 in the left and right bead portions 3.

[0024] In the above-mentioned retread tire, the carcass layer 4 and the reinforcing belt layer 7 form the skeleton of a tire casing 10. A transponder 20 is embedded outside the skeleton of the tire casing 10. In Fig. 1, the transponder 20 is embedded at the interface between the tire casing 10 and the tread rubber layer 30. The transponder 20 is arranged to extend along the tire circumferential direction.

[0025] An example of the transponder 20 that can be used is an RFID (Radio Frequency Identification) tag. As shown in FIGS. 5(a) and 5(b), the transponder 20 has an IC board 21 that stores data and an antenna 22 that transmits and receives data contactlessly. By using such a transponder 20, tire-related information can be written or read as needed, enabling efficient tire management. RFID is an automatic identification technology that is composed of a reader / writer with an antenna and a controller, and an ID tag with an IC board and an antenna, and is capable of wirelessly communicating data.

[0026] 5(a) and 5(b), the entire transponder 20 is preferably covered with a covering layer 23 made of rubber. This covering layer 23 is formed, for example, by sandwiching the front and back surfaces of the transponder 20 between two rubber sheets to cover the entire transponder 20. Protecting the transponder 20 with the covering layer 23 in this manner improves the communication performance and durability of the transponder 20. Furthermore, it is preferable that the relative dielectric constant of the covering layer 23 is lower than the relative dielectric constant of the rubber member adjacent to the covering layer 23. Covering the transponder 20 with the covering layer 23 in this manner contributes to improving the communication performance of the transponder 20.

[0027] A method for manufacturing a retreaded tire having such a structure will now be described. A used tire that has been determined to be retreadable is subjected to buffing, which scrapes off the outer surface of the tread portion, to obtain a base tire 10. This buffing is performed with internal pressure applied to the tire. A transponder 20 is placed in a desired position (for example, the location shown in Figure 1) on the base tire 10 and temporarily fixed with an adhesive or the like.

[0028] Next, the tread rubber layer 30 for retreading is placed on the outer peripheral surface of the base tire 10. At this time, for example, strip-shaped unvulcanized rubber is spirally wound around the outer peripheral surface of the base tire 10 to form the tread rubber layer 30. Then, the assembly of the tread rubber layer 30 and the base tire 10 is placed in a vulcanizer equipped with a tire molding mold and vulcanized. At this time, the assembly of the tread rubber layer 30 and the base tire 10 is pressed against the tire molding mold by a bladder, and the shape of the grooves in the tire molding mold is transferred to the tread rubber layer 30, forming the grooves. In this way, the retread tire of the present invention can be manufactured.

[0029] Alternatively, a precured tread in which grooves have been formed in advance can be used as the tread rubber layer 30. In this case, after a cushion rubber made of a sheet of unvulcanized rubber is attached to the entire outer periphery of the base tire 10, the tread rubber layer 30 (precured tread) is wrapped around the outer periphery of the base tire 10 and both ends are temporarily fixed. The assembly of the tread rubber layer 30 and base tire 10 is then placed in a vulcanizer not equipped with a tire molding mold and vulcanized. At this time, the cushion rubber is vulcanized, and the base tire 10 and the tread rubber layer 30 are bonded together. In this manner, the retread tire of the present invention can be manufactured.

[0030] In the above-described retread tire, the transponder 20 is disposed outside the framework of the base tire 10, and therefore the transponder 20 is disposed in a location close to the outer surface of the tire, thereby improving the communication performance of the transponder 20. Furthermore, even if a transponder already disposed in a tire breaks down during the first run, the transponder can be replaced, and traceability management can be easily performed during the second run.

[0031] In particular, it is preferable that the transponder 20 be disposed between the base tire 10 and the tread rubber layer 30. Disposing the transponder 20 in this manner is preferable because it allows the transponder 20 to be easily disposed during the manufacturing process of the retread tire and does not result in a decrease in yield.

[0032] In the above retread tire, it is preferable that the transponder 20 is disposed on the outer side in the tire width direction of the end 7e in the tire width direction of the widest reinforcement belt layer 72. Since metal members are often present in the tread portion and may be a factor in deteriorating the communication performance of the transponder or the transponder may be damaged by ground pressure, by disposing the transponder 20 away from the reinforcement belt layer 7, the communication performance of the transponder 20 can be effectively improved.

[0033] The transponder 20 should be arranged so that the distance L1 (see FIG. 1) from the end 7e of the widest reinforcement belt layer 72 in the tire width direction to the transponder 20 is preferably 5 mm or more, more preferably 10 mm or more. Furthermore, the transponder 20 should be arranged so that the distance L2 (see FIG. 1) from the end 30e of the tread rubber layer 30 in the tire width direction to the transponder 20 is preferably 5 mm or more, more preferably 10 mm or more. By arranging the transponder 20 at a distance from the end 7e of the reinforcement belt layer 7 and the end 30e of the tread rubber layer 30 in this way, the durability of the tire can be improved. Note that the distances L1 and L2 are both the straight-line distances (shortest distances) from each member to the transponder 20.

[0034] Furthermore, the rubber thickness t (see FIG. 1) on the reinforcement belt layer 7 at the center in the tire width direction of the base tire 10 is preferably 1 mm or more. By appropriately setting the rubber thickness t on the reinforcement belt layer 7 in this manner, the durability of the tire can be effectively improved.

[0035] Fig. 2 shows a modified example of a retread tire according to an embodiment of the present invention. As shown in Fig. 2, the transponder 20 is disposed in a side area of ​​the base tire 10 that is not covered by the tread rubber layer 30. That is, the transponder 20 is disposed relative to the sidewall rubber layer 12. This includes cases where the transponder 20 is disposed on the outer surface of the sidewall rubber layer 12 and cases where the transponder 20 is disposed inside the sidewall rubber layer 12. Fig. 2 shows the former case. By disposing the transponder 20 in this manner, the communication performance of the transponder 20 can be effectively improved.

[0036] Figure 3 shows another modified example of a retread tire according to an embodiment of the present invention. As shown in Figure 3, the transponder 20 is embedded inside the sidewall rubber layer 12. When manufacturing such a retread tire, the sidewall rubber layer 12 is ground to fit the dimensions of the transponder 20, the transponder 20 is placed in the recess formed thereby, the recess is then covered with the same type of rubber as the sidewall rubber layer 12, and the tire is placed in a vulcanization mold and vulcanized. This makes it possible to manufacture a retread tire in which the transponder 20 is placed inside the sidewall rubber layer 12.

[0037] By arranging the transponder 20 in this manner, the transponder 20 is arranged inside the base tire 10, and therefore the durability of the transponder 20 can be improved while the communication performance of the transponder 20 can be effectively improved.

[0038] Fig. 4 shows another modified example of a retread tire according to an embodiment of the present invention. As shown in Fig. 4, the transponder 20 is embedded inside the tread rubber layer 30. By disposing the transponder 20 inside the tread rubber layer 30 in this way, the durability of the tire can be effectively improved. There are no particular restrictions on the embedding position as long as it is inside the tread rubber layer 30, but as shown in Fig. 4, it is preferable that the transponder 20 is disposed on the outer side in the tire width direction of the end 7e of the widest reinforcing belt layer 72 in the tire width direction, and that the distances L1 and L2 are each 5 mm or more. [Example]

[0039] In a retread tire having a tire size of 275 / 80R22.5 and including a base tire having multiple reinforcing belt layers arranged on the outer periphery of the carcass layer in the tread portion, and a tread rubber layer arranged radially outward of this base tire, transponders (RFID tags) were arranged, and tires of conventional example and examples 1 to 10 were produced with the arrangement on the outside of the frame of the base tire, arrangement between the base tire and the tread rubber layer, arrangement widthwise outward from the end of the reinforcing belt layer, distance L1 from the end of the reinforcing belt layer, distance L2 from the end of the tread rubber layer, arrangement in the side region of the base tire, arrangement inside the sidewall rubber layer, presence or absence of a coating layer, magnitude relationship of the relative dielectric constant, rubber thickness on the reinforcing belt layer, and arrangement inside the tread rubber layer set as shown in Table 1.

[0040] In the conventional example, the tag is disposed inside the frame of the tire base (more specifically, between the carcass layer and the inner liner layer). Regarding the "magnitude relationship of the relative permittivity" in Table 1, "same" means that the relative permittivity of the coating layer is the same as that of the rubber member adjacent to the coating layer, and "coating layer" means that the relative permittivity of the coating layer is lower than that of the rubber member adjacent to the coating layer.

[0041] The tag communication properties and tire durability of these test tires were evaluated using the following test methods, and the results are shown in Table 1.

[0042] Tag communication: For each test tire, a reader / writer was used to communicate with the tag. Specifically, the longest communication distance was measured using the reader / writer with an output of 250 mW and a carrier frequency of 860 MHz to 960 MHz. The evaluation results were expressed as an index, with the conventional example being set at 100. The higher the index value, the better the tag's communication performance.

[0043] Tire durability: Each test tire was mounted on a standard rim wheel, the air pressure adjusted to the maximum standard pressure, the load set to the maximum standard load, and a running test was conducted using a drum testing machine at a speed of 48 km / h. The running distance when the tire failed was measured. The evaluation results were expressed as an index, with the conventional example being set at 100. The higher the index value, the better the tire's durability.

[0044] [Table 1]

[0045] As can be seen from Table 1, the retreaded tires of Examples 1 to 10 were able to improve tag communication performance compared to the conventional tire. Furthermore, the retreaded tires of Examples 3 to 10 were able to improve tire durability while also improving tag communication performance.

[0046] The present disclosure includes the following inventions [1] to

[11] . Invention [1] is a retread tire comprising a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and multiple reinforcing belt layers arranged on the outer periphery of the carcass layer in the tread portion, and a tread rubber layer arranged radially outward of the base tire, characterized in that a transponder is arranged outside the skeleton of the base tire. Invention [2] is the retread tire according to invention [1], characterized in that the transponder is disposed between the base tire and the tread rubber layer. Invention [3] is a retread tire according to invention [1] or [2], characterized in that the transponder is arranged on the outer side in the tire width direction of the end portion in the tire width direction of the widest reinforcing belt layer among the plurality of reinforcing belt layers. Invention [4] is a retread tire according to any one of inventions [1] to [3], characterized in that the transponder is arranged at a distance of 5 mm or more from the end in the tire width direction of the widest reinforcing belt layer among the plurality of reinforcing belt layers, and at a distance of 5 mm or more from the end in the tire width direction of the tread rubber layer. Invention [5] is a retread tire according to invention [1], characterized in that the transponder is arranged in a side area of ​​the base tire that is not covered by the tread rubber layer. Invention [6] is a retread tire according to invention [1] or [5], characterized in that the transponder is embedded inside a sidewall rubber layer arranged on the outer side of the carcass layer in the tire width direction. Invention [7] is a retread tire according to any one of inventions [1] to [6], characterized in that the transponder is covered with a covering layer. Invention [8] is a retread tire according to invention [7], characterized in that the relative dielectric constant of the coating layer is lower than the relative dielectric constant of the rubber member adjacent to the coating layer. Invention [9] is a retread tire according to any one of inventions [1] to [8], characterized in that the rubber thickness on the reinforcing belt layer at the center in the tire width direction of the base tire is 1 mm or more. Invention

[10] is a retread tire according to any one of inventions [1], [3], and [4], characterized in that the transponder is embedded inside the tread rubber layer. Invention

[11] is a method for manufacturing a retread tire, characterized in that the tread portion of a used tire is ground to form a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and multiple reinforcing belt layers arranged on the outer periphery of the carcass layer in the tread portion, a transponder is arranged outside the skeleton of this base tire, and then the assembly of the base tire and a tread rubber layer arranged radially outward of this base tire is vulcanized. [Explanation of symbols]

[0047] 1 Tread section 2 Sidewall 3 Bead section 4 carcass layers 5 bead core 6 Bead filler 7 Reinforcement belt layer 10 tires 11 Remaining tread rubber layer 12 Sidewall rubber layer 13 Rim cushion rubber layer 20 Transponder 23 Covering layer 30 tread rubber layer CL Tire centerline

Claims

1. A retread tire comprising: a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and a plurality of reinforcing belt layers arranged on the outer peripheral side of the carcass layer in the tread portion; and a tread rubber layer arranged radially outward of the base tire, wherein a transponder is arranged outside the skeleton of the base tire.

2. 2. The retread tire according to claim 1, wherein the transponder is disposed between the base tire and the tread rubber layer.

3. 3. The retread tire according to claim 1, wherein the transponder is arranged on the outer side in the tire width direction of an end portion in the tire width direction of the widest reinforcing belt layer among the plurality of reinforcing belt layers.

4. 3. The retread tire according to claim 1, wherein the transponder is arranged at a distance of 5 mm or more from an end portion in the tire width direction of the widest reinforcing belt layer among the plurality of reinforcing belt layers, and is arranged at a distance of 5 mm or more from an end portion in the tire width direction of the tread rubber layer.

5. 2. The retread tire according to claim 1, wherein the transponder is disposed in a side area of ​​the base tire that is not covered by the tread rubber layer.

6. 6. The retread tire according to claim 1, wherein the transponder is embedded inside a sidewall rubber layer disposed outside the carcass layer in the tire width direction.

7. 3. The retread tire according to claim 1, wherein the transponder is covered with a covering layer.

8. 8. The retread tire according to claim 7, wherein the dielectric constant of the cover layer is lower than the dielectric constant of a rubber member adjacent to the cover layer.

9. 3. The retread tire according to claim 1, wherein the thickness of the rubber on the reinforcing belt layer at the center in the tire width direction of the tire base is 1 mm or more.

10. 2. The retread tire according to claim 1, wherein the transponder is embedded inside the tread rubber layer.

11. A method for manufacturing a retread tire, characterized in that the tread portion of a used tire is ground to form a base tire having a skeleton consisting of a carcass layer mounted between a pair of bead portions and a plurality of reinforcing belt layers arranged on the outer peripheral side of the carcass layer in the tread portion, a transponder is arranged on the outside of the skeleton of this base tire, and then the assembly of the base tire and a tread rubber layer arranged on the radially outer side of this base tire is vulcanized.

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