JP2022076891A - Pneumatic tire - Google Patents

Abstract

To improve uniformity of a weight balance in a tire circumferential direction, in a pneumatic tire having a sealing layer provided on an inner surface of the tire.SOLUTION: In a pneumatic tire T having a sealing layer 5 provided on an inner surface of the tire, the sealing layer 5 comprises a plurality of belt-like sealed bodies 6 that are wound by going one or more full circles in a tire circumferential direction X. The plurality of belt-like sealed bodies 6 are arranged in such a manner as to deviate in a tire width direction Y so as to partially overlap each other in the tire width direction Y, and a winding start end 6a is arranged in such a manner as to deviate in the tire circumferential direction X.SELECTED DRAWING: Figure 2

Description

The present invention relates to a pneumatic tire.

Conventionally, a pneumatic tire in which a sealing agent for preventing a puncture called a sealant is applied to the inner surface of the tire has been known (see, for example, Patent Document 1 below).

In the pneumatic tire described in Patent Document 1 below, a sealing body in which a sealing agent is formed in a band shape is spirally wound around the inner surface of the tire from one side to the other side in the tire width direction to form a sealing layer. ..

Japanese Unexamined Patent Publication No. 2014-217953

However, when the band-shaped sealing body is spirally wound from one side to the other side in the tire width direction to form a sealing layer, the amount of overlapping of the sealing agent at the application start position and the application end position of the sealant is larger than that of the other parts. Therefore, there is a problem that the weight balance deteriorates in the tire circumferential direction.

The present invention has been made in view of such circumstances, and an object of the present invention is to improve the uniformity of weight balance in the tire circumferential direction in a pneumatic tire provided with a sealing layer on the inner surface of the tire.

The pneumatic tire according to the embodiment of the present invention is a pneumatic tire provided with a sealing layer on the inner surface of the tire. The plurality of strip-shaped sealed bodies are arranged so as to be offset in the tire width direction so that some of them overlap in the tire width direction, and the winding start end portions are arranged so as to be displaced in the tire circumferential direction.

In the pneumatic tire, the uniformity of the weight balance in the circumferential direction of the tire provided with the sealing layer on the inner surface of the tire can be improved.

Sectional drawing of the pneumatic tire of one Embodiment of this invention The view which developed the sealing layer of the pneumatic tire of FIG. 1 on a plane. Explanatory drawing showing a manufacturing apparatus of a pneumatic tire The figure which developed the sealing layer of the pneumatic tire of the modification of this invention on a plane. Explanatory drawing which outlines the tire manufacturing apparatus of the modification of this invention.

As shown in FIG. 1, the pneumatic tire (hereinafter, also referred to as a tire) T of the present embodiment includes a tread 1 forming a contact patch and a pair of shoulders extending inward in the tire radial direction from both ends of the tread 1 in the width direction. 2, 2, sidewalls 3, 3 and beads 4, 4 are provided, and a sealing layer 5 provided on the inner surface of the tread 1 and the pair of shoulders 2, 2 is provided on the inner surface of the tire. Various general tire structures can be adopted except for the sealing layer 5 provided on the inner surface of the tire. In the present specification, the vulcanized tire without the sealing layer 5 may also be referred to as a tire T.

The sealing layer 5 is composed of a plurality of strip-shaped sealing bodies 6 in which a sealing agent having high adhesiveness is formed in an elongated strip shape, and when a hole penetrating the tread 1 of the tire T is formed by nailing or the like, this hole is formed. It automatically seals to prevent air leakage and suppresses puncture of the tire T. That is, the tire T is a self-sealing type pneumatic tire.

As shown in FIG. 2, the plurality of strip-shaped sealing bodies 6 constituting the sealing layer 5 form an elongated strip extending in the tire circumferential direction X. The band-shaped sealing body 6 has a sealing portion 7 wound around the inner surface of the tire along the tire circumferential direction X, and a circumferential laminated portion 8 in which the band-shaped sealing body 6 overlaps at the winding start end portion 6a and the winding end portion 6b of the band-shaped sealing body 6. And.

The plurality of strip-shaped sealed bodies 6 are provided so that the winding positions are shifted in the tire width direction Y so that a part of the tire width direction Y overlaps. That is, the plurality of strip-shaped sealing bodies 6 are smaller than the width dimension so that the end portion of the strip-shaped sealing body 6 of 1 in the tire width direction overlaps the other strip-shaped sealing bodies 6 adjacent to the tire width direction Y over the entire circumferential direction. It is provided on the inner surface of the tire by shifting it by a predetermined pitch P in the tire width direction Y. Further, in the plurality of strip-shaped sealed bodies 6, the winding start end portion 6a is arranged so as to be displaced in the tire circumferential direction X.

In the present embodiment, the sealing layer 5 is composed of a plurality of N strip-shaped sealing bodies 6 (N is an integer, for example, 45). Each of the strip-shaped sealed bodies 6 has a sealing portion 7 wound around the inner surface of the tire in parallel with the tire circumferential direction X, and a circumferential laminated portion 8 in which the winding end portion 6b is overlapped on the winding start end portion 6a. And.

Further, the winding start end portion 6a of the strip-shaped sealing body 6 of 1 is arranged at a position shifted by 360 / N degrees from the winding starting end portion 6a of the other strip-shaped sealing body 6 adjacent to one side in the tire width direction to one side in the tire circumferential direction. Has been done.

That is, in the sealing layer 5, a plurality of strip-shaped sealing bodies 6 are arranged so as to be offset by a predetermined pitch P in the tire width direction Y, and the strip-shaped sealing body 6 located at a position shifted to one side in the tire width direction is wound around the tire and the starting end portion 6a is a tire. A plurality of winding start end portions 6a are arranged at equal intervals in the tire circumferential direction X so as to be displaced to one side in the circumferential direction.

The sealing agent constituting the strip-shaped sealing body 6 is, for example, an unvulcanized or semi-vulcanized butyl rubber, a plasticizing agent such as polyisobutylene or polybutene, and a tackifier such as a thermoplastic olefin / diolefin copolymer. And, a material containing a filler such as carbon black or silica can be used. The sealing agent is not limited to this, and other known sealing agents conventionally used can also be used.

Next, the tire manufacturing apparatus 10 that forms the sealing layer 5 on the inner surface of the tire T will be described with reference to FIG.

The tire manufacturing apparatus 10 has a holding device 20 that rotatably holds the vulcanized tire T around the tire rotation axis L, and a strip-shaped sealing body 6 wound around the inner surface of the tire T held by the holding device 20. A coating device 50 for forming the sealing layer 5 is provided.

The holding device 20 includes a holding portion 21 that holds the tire T from the outside in the radial direction, a rotating plate 22 that supports the holding portion 21, a driving portion 23 that moves the holding portion 21 and rotates the rotating plate 22, and a rotating plate. A moving mechanism 24 for moving the 22 and the driving unit 23 is provided.

In the holding device 20, the driving unit 23 rotates the tire T held on the rotating plate 22 by the holding portion 21 around the rotation axis of the tire together with the rotating plate 22, and the moving mechanism 24 rotates the tire together with the rotating plate 22 and the driving unit 23. Change the position and angle of T.

The coating device 50 includes a supply unit 51 for pressure-feeding the sealing agent, and a nozzle 52 to which the sealing agent pressure-fed from the supply unit 51 is supplied. The supply unit 51 includes a gear pump, and pressurizes a certain amount of the sealing agent to the nozzle 52 while the gear pump is operating, and shuts off the supply of the sealing agent to the nozzle 52 when the gear pump is stopped.

The discharge port 52a provided at the tip of the nozzle 52 is arranged so as to face the inner surface of the tire T, and discharges the sealing agent supplied from the supply unit 51 to the inner surface of the tire T. The discharge port 52a has a substantially rectangular opening shape having a dimension in the width direction (direction parallel to the tire width direction) of about 2 to 20 mm and a dimension in the thickness direction of about 2 to 10 mm, and the width of the tire T. Discharge while molding the band-shaped sealed body 6 into a band shape narrower than the dimensions. The opening shape of the discharge port 52a can be set to any shape such as a round shape or a flat triangular shape in addition to the rectangular shape as described above.

The holding device 20 and the coating device 50 described above are each connected to a control device (not shown), and the operation thereof is controlled by the control device.

Next, a method of manufacturing the above-mentioned pneumatic tire T by using the above-mentioned tire manufacturing apparatus 10 will be described.

First, the vulcanized tire T is set on the rotating plate 22 of the holding device 20, and the tire T is fixed on the rotating plate 22 by the holding portion 21.

Then, the moving mechanism 24 moves the tire T together with the rotating plate 22 and the drive unit 23, inserts the nozzle 52 from the inside of the bead 4 of the tire T into the inside of the tire, and inserts the nozzle 52 into the discharge port 52a of the nozzle 52 of one shoulder 2. Facing the inner predetermined position.

After that, the drive unit 23 rotates the rotary plate 22 to rotate the tire T around the tire rotation shaft L, and drives the gear pump provided in the coating device 50 to pump a constant amount of the sealing agent to the nozzle 52. do. As a result, the strip-shaped sealed body 6 having a cross-sectional shape corresponding to the opening shape of the discharge port 52a is discharged from the discharge port 52a toward the inner surface of the tire, and the strip-shaped sealed body 6 is started to be attached to the inner surface of the tire.

Then, after the tire T makes one rotation after starting the attachment of the strip-shaped sealed body 6, when the tire T further rotates in the tire circumferential direction X by a predetermined length to form the circumferential laminated portion 8, the gear pump is stopped and the nozzle is nozzleed. The supply of the sealing agent to 52 is cut off, and the attachment of the band-shaped sealing body 6 is stopped. At the same time, the drive unit 23 stops the rotation of the tire T. As a result, the first strip-shaped sealed body 6 having the sealing portion 7 and the circumferential laminated portion 8 is wound around the inner surface of the tire.

When the winding of the first strip-shaped sealed body 6 is completed, the tire T is moved so that the discharge port 52a faces the winding start position of the second strip-shaped sealed body 6. That is, the moving mechanism 24 moves the tire T to one side in the tire width direction by a predetermined pitch P set to a dimension slightly smaller than the width dimension of the strip-shaped sealed body 6. In addition to this, the moving mechanism 24 has a rotation shaft of the tire T so that the direction in which the band-shaped sealed body 6 is discharged from the discharge port 52a coincides with the normal direction of the inner surface of the tire at the position where the band-shaped sealed body 6 is attached. Adjust the direction. Further, the drive unit 23 rotates the tire T to one side in the tire circumferential direction by 360 / N degrees.

When the discharge port 52a moves to the winding start position of the second strip-shaped sealing body 6, the second strip-shaped sealing body 6 is wound around the inner surface of the tire. That is, the drive unit 23 rotates the tire T around the tire rotation shaft L, and the gear pump provided in the coating device 50 is driven to discharge the band-shaped sealed body 6 from the discharge port 52a toward the inner surface of the tire. The attachment of the second strip-shaped sealed body 6 is started. Then, as with the first strip-shaped sealing body 6, the tire T makes one rotation after starting the attachment of the second strip-shaped sealing body 6, and then further rotates in the tire circumferential direction X by a predetermined length. When the circumferential laminated portion 8 is formed, the gear pump is stopped and the rotation of the tire T is stopped.

As a result, the tire is arranged so as to be offset from one side in the tire width direction so as to overlap one side in the tire width direction of the first strip-shaped sealing body 6, and the tire is arranged from the winding start end portion 6a of the first strip-shaped sealing body 6. A second strip-shaped sealed body 6 having a winding start end portion 6a arranged at a position shifted to one side in the circumferential direction is wound around the inner surface of the tire.

After that, by repeating the movement of the discharge port 52a to the next winding start position of the band-shaped sealing body 6 and the winding of the band-shaped sealing body 6 around the inner surface of the tire as described above, the plurality of band-shaped sealing bodies 6 have the tire width. A sealing layer 5 as shown in FIG. 2 is formed on the inner surface of the tire, which is arranged so as to be offset in the direction Y and the plurality of winding start ends 6a are arranged so as to be offset in the tire circumferential direction X at equal intervals.

In the pneumatic tire T of the present embodiment, the sealing layer 5 is composed of a plurality of strip-shaped sealing bodies 6, and the winding start ends of the plurality of strip-shaped sealing bodies 6 are arranged so as to be offset in the tire circumferential direction X. The positions where the bodies 6 overlap can be dispersed in the tire peripheral direction X, and the uniformity of the weight balance in the tire peripheral direction X can be improved.

In the present embodiment, since the sealing layer 5 is composed of a plurality of strip-shaped sealing bodies 6 wound once in parallel with the tire circumferential direction X, the thickness of the strip-shaped sealing body 6 can be uniformly wound. Further, the uniformity of the weight balance in the tire circumferential direction X can be improved.

(Change example)
The above embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention.

For example, in the above-described embodiment, the sealing layer 5 is configured by arranging a plurality of strip-shaped sealing bodies 6 wound around once in parallel with the tire circumferential direction X so as to be offset in the tire width direction Y by a predetermined pitch P. However, the sealing layer 5 may be formed by a plurality of strip-shaped sealing bodies 106 wound around a plurality of circumferences in the tire circumferential direction X.

For example, as shown in FIG. 4, the band-shaped sealing body 106 constituting the sealing layer 5 is wound around the tire circumferential direction X one circumference (that is, 360 degrees) so that a part of the tire width direction Y overlaps. The tire is wound by moving the winding position to one side in the tire width direction by a predetermined pitch P, and such winding in the tire circumferential direction X and movement of the winding position are repeated for a plurality of laps (3 laps in the case of FIG. 4). It is wrapped around the inner surface.

In such a strip-shaped sealed body 106 wound three times in the tire circumferential direction X, the winding start end portion 106a is arranged so as to be offset in the tire width direction Y by a length three times the predetermined pitch P, and the tire circumference. The sealing layer 5 is formed by arranging a plurality of tires at different positions in the tire circumferential direction X so as to be arranged at equal intervals in the direction X.

Even in such a case, the same action and effect as those of the above-described embodiment can be obtained.

Further, in the above-described embodiment, the case where the winding start end portions 6a of the plurality of strip-shaped sealing bodies 6 constituting the sealing layer 5 are all arranged at different positions in the tire circumferential direction X has been described, but some of the strip-shaped sealing bodies 6 have been described. In the sealed body 6, the winding start end portion may be arranged at the same position in the tire circumferential direction X.

Further, in the above-described embodiment, the rotating plate 22 and the driving unit 23 are attached to the tip of the arm 24a of the industrial robot having three axes of freedom, and the tire T is horizontally and while the strip-shaped sealed body 6 is attached. Although the tire rotation axis direction of the tire T is changed while moving in the vertical direction, the strip-shaped sealing body 6 may be attached to the inner surface of the tire by moving the discharge port 52a of the nozzle 52.

Specifically, as shown in FIG. 5, the rotary plate 22 and the drive unit 23 are fixed to the ground surface, and the discharge port 52a of the nozzle 52 is attached to the tip of the arm 60a of the industrial robot 60 having three degrees of freedom. 6 may be attached to the inner surface of the tire by changing the direction in which the sealing agent is discharged by the discharging port 52a while moving the discharging port 52a in the horizontal direction and the vertical direction. Even in such a case, the tire T does not shift in the direction of the tire rotation axis during the rotation of the tire T, and the same effects as those in the above embodiment can be obtained.

1 ... tread, 2 ... shoulder, 3 ... sidewall, 4 ... bead, 5 ... sealing layer, 6 ... strip-shaped sealed body, 6a ... winding start end, 6b ... winding end, 7 ... sealing, 8 ... circumferential lamination Unit, 10 ... Tire manufacturing device, 20 ... Holding device, 21 ... Holding part, 22 ... Rotating plate, 23 ... Drive unit, 24 ... Moving mechanism, 50 ... Coating device, 51 ... Supply unit, 52 ... Nozzle, 52a ... Discharge Exit

Claims (4)

In a pneumatic tire with a sealing layer on the inner surface of the tire
The sealing layer includes a plurality of strip-shaped sealing bodies wound around one or a plurality of turns in the tire circumferential direction.
The plurality of strip-shaped sealed bodies are pneumatic tires that are arranged so as to be offset in the tire width direction so that parts of the tire width direction overlap each other, and the winding start end portion is displaced in the tire circumferential direction. The pneumatic tire according to claim 1, wherein the band-shaped sealed body is wound around the tire in the circumferential direction. The pneumatic tire according to claim 1 or 2, wherein the winding start ends of the plurality of strip-shaped sealed bodies are arranged at equal intervals in the tire circumferential direction. Assuming that the number of the strip-shaped sealed bodies provided on the sealing layer is N, the winding start ends of the strip-shaped sealed bodies adjacent to each other in the tire width direction are arranged so as to be offset by 360 / N degrees to one side in the tire circumferential direction. The pneumatic tire according to claim 3.

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