JP2002036813A - Tubeless tire and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air leak preventing means together with its manufacturing method for a tubeless tire capable of preventing air leak certainly using a simple configuration. SOLUTION: A tubeless tire 1 according to the invention is structured so that an inner liner 5 for keeping air-tightness is adhered to the whole inner surface of an outer layer 4 including a tread part 3 contacting with the ground surface and fixed to a wheel by a pair of bead parts 2 and a seal liner 6 consisting of a plurality of band-shaped resilient pieces are formed on the inside surface of the inner liner 5, wherein the seal liner 6 is composed of an adhesion part 6a adhered to the inner liner 5 and a non-adhesion part 6b overlapping on another seal liner 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a tubeless tire capable of preventing air from leaking from a tire even when the tire is injured by a nail or the like while the vehicle is running, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In a tubeless tire, an inner liner layer made of rubber is entirely adhered to an inner portion of an outer layer portion having a tread portion or the like in contact with the ground, thereby keeping the inside of the tire airtight. Here, in such a tubeless tire, when a foreign matter such as a nail or a screw is stabbed into the tubeless tire during running of the vehicle, air leaks from the punctured portion, and the internal pressure of the tire decreases, and the vehicle becomes In some cases, means for preventing air leakage are provided to prevent the vehicle from running improperly.

As a conventional example of the means for preventing air leakage of a tubeless tire, there is a sealant made of an adhesive rubber or the like applied to the inner surface of an inner liner layer. The sealant agent flows through the punctured portion formed by penetrating a through hole or the like to block the punctured portion, thereby preventing the outflow of air by a so-called self-sealing action. As a method for producing such a sealant tire, first, an inner liner layer and an outer layer portion are sequentially wound around a cylindrical forming drum to form a laminate. Next, the laminate was formed into a tire shape and then vulcanized to produce a tubeless tire, and thereafter, a sealant was applied to the inner surface of the inner liner layer of the tubeless tire.

[0004]

However, in such a sealant tire, since the thickness of the sealant must be about 4 mm or more in order to surely exhibit the self-sealing action, the weight of the tubeless tire is greatly increased. Was causing the increase. Further, in order to quickly exert the self-sealing effect of the sealant when a large nail or the like is pierced, it is desirable that the viscosity of the sealant is low. However, if the viscosity of the sealant is low, the rotational vibration of the sealant tire during running may be reduced. When the temperature rises due to the load fluctuation accompanying the above, the fluidity of the sealant tends to increase. If the sealant has fluidity, the sealant may be deviated in the circumferential direction of the sealant tire or the like, thereby disturbing the weight balance of the sealant tire, which may cause unnecessary vibration in the vehicle. .

[0005] Further, in the manufacturing process, the bladder of the vulcanization molding machine and the sealant are stuck.
The vulcanization molding process and the sealant application process need to be performed separately, which greatly reduces the productivity of tubeless tires and raises the production cost of tubeless tires. Therefore, an object of the present invention is to provide an air leak preventing means capable of reliably preventing air leak without increasing the weight of a tubeless tire or breaking the weight balance of the tubeless tire, and including the air leak preventing means. To provide a manufacturing method capable of easily manufacturing a tubeless tire.

[0006]

According to a first aspect of the present invention, there is provided an outer layer portion including a tread portion fixed to a wheel by a pair of beads and in contact with the ground; The inner liner layer comprises a plurality of band-shaped elastic bodies on the inner surface of the inner liner layer, wherein the elastic body is A tubeless tire comprising a bonded portion bonded to the liner layer and a non-bonded portion overlapping another elastic body.

According to the tubeless tire of the first aspect, the belt-shaped elastic body has an adhesive portion and a non-adhesive portion adhered to the inner liner layer, and the non-adhesive portion overlaps with another elastic body. With this configuration, when the nail penetrates the inner liner layer, the non-adhesive portion of the elastic body is pressed so as to be pushed by the nail. On the other hand, when the nail is removed, the non-adhesive portion that has been turned back returns to its original position due to the elastic force, and the non-adhesive portion is pressed against the inner liner layer by the internal pressure of the tubeless tire. Can be reliably prevented. In addition, since the elastic body itself does not have fluidity, the tubeless tire does not break the weight balance when the vehicle is running, and the elastic body covers the puncture part and prevents air leakage, so a thin elastic body Even if there is, the effect can be sufficiently exhibited, so that an increase in the weight of the tubeless tire can be suppressed.

According to a second aspect of the present invention, there is provided the tubeless tire according to the first aspect, wherein the elastic body has a slit in a width direction thereof.

According to the tubeless tire of the second aspect, only the elastic body in the vicinity of the punctured portion where the foreign matter has penetrated turns up or returns to the original position, so that the foreign matter which has penetrated the inner liner layer can be prevented. The non-bonded portion of the elastic body can be deformed with good responsiveness.

Further, the invention according to claim 3 provides the tubeless tire according to claim 1 or 2, wherein a sealant having a self-sealing action is applied to the elastic body.

According to the tubeless tire according to the third aspect, the punctured portion is covered with the non-adhered portion of the elastic body, and the punctured portion is closed by the self-sealing action of the sealant, so that air leakage can be more reliably prevented. In addition, since the sealant is used as an auxiliary of the elastic body, the thickness of the sealant itself can be made thinner than that of the conventional sealant, so that an increase in weight of the tubeless tire can be suppressed.

According to a fourth aspect of the present invention, there is provided a tubeless tire formed by sequentially winding an inner liner layer for maintaining airtightness and an outer layer portion including a tread portion in contact with the ground on a cylindrical forming drum. In the manufacturing method, before winding the inner liner layer around the forming drum, a plurality of belt-like elastic bodies are stretched on the forming drum such that a part of the elastic bodies overlaps with another elastic body. The manufacturing method was adopted.

According to the method for manufacturing a tubeless tire according to the fourth aspect, the elastic body can be easily bonded to the inner liner layer simply by adding the step of stretching the elastic body. Therefore, it is not necessary to make a significant change in the manufacturing apparatus and the man-hour is not greatly increased, so that the productivity can be improved as compared with the conventional sealant tire. In addition, the stretching of the elastic body refers to the circumferential direction of the forming drum,
This means that the elastic body is provided so as not to be slackened in an arbitrary direction such as a major axis direction or a direction intersecting the major axis direction, and one form of the elastic body includes winding along the circumferential direction of the forming drum.

[0014] The invention according to claim 5 is a method of laminating an inner liner layer for maintaining airtightness and an outer layer portion including a tread portion in contact with the ground, and vulcanizing a green tire formed into a tire shape. A method for producing a tubeless tire is characterized in that a band-shaped elastic body is adhered to the inner surface of an inner liner layer so that a part of the elastic body overlaps with another elastic body.

When a tubeless tire is manufactured by the manufacturing method according to the fifth aspect, a conventional manufacturing apparatus can be used up to the vulcanization molding step, so that a change in manufacturing equipment can be minimized.

[0016]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a partial cross-sectional view of the tubeless tire of the present embodiment. The tubeless tire 1 is used by fixing a pair of bead portions 2 to a wheel of an axle, and is entirely adhered to an outer layer portion 4 including a bead portion 2 and a tread portion 3 in contact with the ground, and an inner surface of the outer layer portion 4. The inner liner layer 5 includes a rubber inner liner layer 5 for maintaining the airtightness of the tubeless tire 1, and a plurality of band-like elastic liner seal liner layers 6 provided on the inner surface of the inner liner layer 5.

Next, each component of the tubeless tire 1 will be described. First, the outer layer portion 4 includes a pair of bead portions 2 formed so as to surround the bead wire 7.
And a tread portion 3 on which a tread pattern for gripping the ground is formed, and a sidewall 8 connecting the bead portion 2 and the tread portion 3. Further, a plurality of belts 9 for adjusting the rigidity of the tread portion 3 are inserted inside the tread portion 3. In addition, each component of the outer layer part 4 is integrally bonded by an adhesive or a vulcanization molding process.

The inner liner layer 5 is formed of rubber, and is adhered to the entire surface so as to cover the inner surface of the outer layer portion 4 to prevent the air inside the tubeless tire 1 from leaking to the outside.

Further, as shown in FIG. 2, the seal liner layer 6 is a band-shaped elastic body arranged along the circumferential direction of the tubeless tire 1, and the inner liner layer 5
And a non-adhesive portion 6b that can be deformed by a foreign substance such as a nail penetrating the inner liner layer 5, and the non-adhesive portion 6b overlaps the other seal liner layer 6. It is arranged as follows. Here, the seal liner layer 6 is provided only on the inner surface of the region where the tubeless tire 1 is in contact with the ground.

As shown in FIG. 3, when a foreign matter F such as a nail sticks into the tubeless tire 1 and penetrates through the inner liner layer 5, the non-adhered portion 6b of the seal liner layer 6 avoids the penetrated foreign matter F. Since it is deformed, the non-adhesive portion 6b is not damaged. Thereafter, when the foreign matter F comes out of the tubeless tire 1, the non-adhesive portion 6b returns to the original position by the elastic force. In addition, since the non-adhesive portion 6b is pressed against the adhesive portion 6a of the inner liner layer 5 or the seal liner layer 6 by the internal pressure of the tubeless tire 1,
Air leakage from the puncture portion 10 can be prevented.

Here, in order to facilitate deformation due to foreign matter, it is desirable that the thickness of the seal liner layer 6 is 3 mm or less and the width thereof is about 5 to 50 mm. Further, the width of the bonding portion 6a is set to 5 to 5 with respect to the width of the seal liner layer 6.
The seal liner layer 6 is made to be about 20 mm, and the adjacent seal liner layers 6 are arranged so that 20 to 80% of the width of the seal liner layers are overlapped with each other. 5 can be securely bonded. In FIG. 2, the seal liner layer 6 has a three-stage shape in the width direction.
The shape may not have a step, and the cross-sectional shape may be an arbitrary shape. In addition, when the seal liner layers 6 are arranged without leaving a gap, air leakage can be more effectively prevented.

Examples of the material constituting the seal liner layer 6 include butyl rubber, a mixture of butyl rubber and latex rubber, and an elastic material containing styrene / butadiene rubber or natural rubber as a main component. Is used.
Furthermore, a resin having elasticity such as VeraRen (registered trademark of Yokohama Rubber Co., Ltd.) may be mixed with them to improve the non-adhesion portion 6b of the seal liner layer 6 with respect to foreign matter penetration.

Further, the seal liner layer 6 is preferably a single layer made of the above-mentioned rubber or the like. You can also. further,
In order to increase the strength of the seal liner layer 6, fibers such as polyester, polyamide, and aramid may be bonded as a reinforcing material, or a composite material obtained by mixing the fibers. The direction of the reinforcing material to be bonded or mixed may be any of the longitudinal direction, the width direction, and the oblique direction of the seal liner layer 6,
A plurality of fiber layers can be laminated so as to intersect.

Here, in the width direction of the seal liner layer 6,
A slit 11 as shown in FIG. 4 can be provided.
When the foreign matter F penetrates the tubeless tire 1 having such a seal liner layer 6, the area deformed by the foreign matter F is only the liner piece 6c partitioned by the slit 11, so that the movement of the foreign matter F is quickly followed. be able to. Alternatively, a thin portion may be formed instead of the slit 11, and the thin portion may be torn by pressing the seal liner layer 6 against foreign matter.

Further, as shown in FIG.
Liner layer 1 with thinly applied sealant 12
6 can also be used. Seal liner layer 1
6, the air leakage of the tubeless tire 1 can be more reliably prevented by using the self-sealing action of the sealant 12 together. In this case, the sealant agent 12 is preferably applied uniformly to the surface of the non-adhesive portion 16b which comes into contact with the inner liner layer 5 or another seal liner layer 16, and the amount of the sealant agent 12 is used together with the seal liner layer 16. Therefore, it is possible to reduce the amount (for example, the thickness is 3 mm or less) as compared with the conventional application amount of the sealant. In addition, the sealant 1 applied in this manner
2 does not directly touch the bladder of the vulcanization molding machine at the time of vulcanization molding of the tubeless tire 1 described later,
Since the integral vulcanization molding becomes possible, the productivity of the tubeless tire 1 can be improved.

Next, a method of manufacturing the tubeless tire 1 will be described with reference to FIGS. 1 and 6 by taking, as an example, a case where the seal liner layer 6 is wound around the forming drum 21 in the circumferential direction. FIG. 6 is a schematic diagram of a manufacturing process for manufacturing the raw tire 20 before the vulcanization forming process. The forming drum 21 is configured such that both end portions 21a are slidable toward a center portion 21b. The central portion 21b is composed of a plurality of divided surfaces, and the divided surfaces are provided with a mechanism for blowing out compressed air while moving so as to increase the diameter of the forming drum 21.

First, a band-shaped elastic body 22 is wound around a cylindrical forming drum 21 rotating at a predetermined speed. FIG.
As shown in (a), the elastic body 22 is wound around the forming drum 21 and then cut by an unillustrated cutting means, and the ends are joined to form an annular shape. The seal liner layer 6 is formed. Then, the next elastic body 22 is wound so as to overlap the seal liner layer 6 by a predetermined amount, and thereafter, the seal liner layer 6 is wound similarly.

Next, as shown in FIG. 6B, a rubber sheet 23 is wound around the seal liner layer 6, and the ends thereof are joined to form the inner liner layer 5. Further, as shown in FIG. 6C, the belt 9, the sidewalls 8, the tread portion 4, and the like are wound around the inner liner layer 5, and the bead wires 7 are attached to both ends of the inner liner layer 5, thereby forming the tubeless tire 1. A stacked body 24 is formed by stacking all the constituent elements to be formed on the forming drum 21. Here, by sliding both end portions 21a of the forming drum 21 toward the center portion 21b so as to reduce the width of the forming drum 21, both end portions of the laminated body 24 are narrowed, and the bead portion 2 is formed. . At the same time, the dividing surface of the central portion 21b of the forming drum 21 is
By blowing out compressed air while moving so as to increase the diameter of the tire, the sidewall 8 is formed by inflating the central portion of the laminate 24, and the raw tire 20 as shown in FIG. Is done.

Further, the green tire 20 is charged into a vulcanization molding machine, vulcanized at a predetermined temperature for a predetermined time, and all the components except for the non-adhered portion of the seal liner layer 6 are integrated to form a tubeless. Tire 1 is completed. Here, the application of the adhesive to the bonding portion 6a (see FIG. 1) where the seal liner layer 6 is bonded to the inner liner layer 5 is performed by using the
1 may be performed, or may be performed after winding on the forming drum 21.

When the tubeless tire 1 is manufactured in this manner, it is only necessary to add a step of winding the seal liner layer 6 to the conventional method for manufacturing a tubeless tire. Does not greatly increase, so that the tubeless tire 1 can be manufactured without lowering the productivity.
When the seal liner layer 6 is provided in the radial direction of the tubeless tire 1 or obliquely to the radial direction, the seal liner layer 6 is formed along the long axis direction of the forming drum 21 or obliquely to the long axis direction. The layer 6 is stretched. Also in this case, the seal liner layer 6 is stretched so that a part thereof overlaps with each other.

As another manufacturing method, as shown in FIG. 7, a seal liner layer 6 can be bonded to the tubeless tire 1 after vulcanization molding. As shown in FIG. 7A, a mold release agent 31 for facilitating removal of the tubeless tire 30 from the bladder of the vulcanization molding machine is applied to the inner surface of the tubeless tire 30 after vulcanization molding. First, the inner surface of the inner liner layer 5 of the tubeless tire 30 is washed to remove the release agent 31. next,
After the inner surface of the washed tubeless tire 30 is dried, as shown in FIG.
The seal liner layer 6 is formed by adhering the adhesive portion 6a to the inner liner layer 5 along the circumferential direction. In addition,
As described above, the seal liner layer 6 is attached to the inner surface of the inner liner layer 5 such that the non-adhesive portion 6b overlaps the adjacent seal liner layer 6.

In the method of manufacturing the tubeless tire 30, the conventional manufacturing apparatus can be used as it is until the vulcanization molding step, so that the change of the manufacturing equipment can be minimized. This manufacturing method is particularly useful when the seal liner layer 6 is made of a material that adheres to the inner liner layer 5 or the adjacent seal liner layer 6 during vulcanization.

The present invention is not limited to the embodiment but can be widely applied. For example, instead of attaching the seal liner layer 6 in the circumferential direction of the tubeless tire 1, the seal liner layer 6 can be attached diagonally to the radial direction of the tubeless tire 1 or the circumferential direction of the tubeless tire 1. Furthermore, you may affix so that several seal liner layers 6 may cross. After the plurality of seal liner layers 6 are formed in a sheet shape, the seal liner layers 6 can be attached to the inner surface of the tubeless tire 1. Furthermore, the seal liner layer 6 has been described as being attached such that only one of the seal liner layers 6 overlaps the adjacent seal liner layer 6 in the width direction, but the center of the seal liner layer 6 in the width direction is the inner liner layer 5. And may be attached so that both ends in the width direction overlap with the adjacent seal liner layers 6 respectively.

[0034]

The present invention provides a tubeless tire in which a seal liner layer, which is a band-shaped elastic body, is deformably adhered to the inner surface of the inner liner layer. By closing, it is possible to prevent air leakage of the tubeless tire. Also,
A slit is provided in the width direction of the seal liner layer so that only the vicinity of the punctured portion where the foreign matter has penetrated is deformed, so that the seal liner layer is deformed with good responsiveness to the foreign matter penetrating the inner liner layer. Can be.

Further, since a sealant having a self-sealing action is applied to the seal liner layer, and the self-sealing action of the sealant is used in combination with the sealing of the punctured portion, air leakage can be more reliably prevented. And, when manufacturing a tubeless tire, before winding the inner liner layer around the forming drum, a band-shaped elastic body is stretched over the forming drum to form a seal liner layer, or after vulcanizing the green tire, Since the seal liner layer was formed by bonding the band-shaped elastic body to the inner surface of the inner liner layer,
The change from the manufacturing process of the conventional tubeless tire can be minimized, and the productivity can be maintained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a tubeless tire of the present invention.

FIG. 2 is a perspective sectional view showing a seal liner layer.

FIG. 3 is a partially enlarged cross-sectional view showing a state where a nail is stuck in a tubeless tire.

FIG. 4 is a perspective view of an essential part showing a seal liner layer having a slit in a width direction.

FIG. 5 is a partially enlarged sectional view showing a tubeless tire having a seal liner layer coated with a sealant.

FIG. 6 is a schematic view illustrating a method for manufacturing a tubeless tire of the present invention.

FIG. 7 is a schematic view showing another method of manufacturing the tubeless tire of the present invention.

[Explanation of symbols]

 1, 30 tubeless tire 2 bead portion 3 tread portion 4 outer layer portion 5 inner liner layer 6, 16 seal liner layer (belt-like elastic body) 6a bonded portion 6b non-bonded portion 11 slit 12 sealant 20 raw tire 21 forming drum 24 lamination Body 31 Release agent

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Claims (5)

[Claims] 1. An outer layer portion including a tread portion fixed to a wheel by a pair of bead portions and in contact with the ground, and an inner liner layer adhered to an inner surface of the outer layer portion to maintain airtightness. In the tubeless tire to be provided, the inner surface of the inner liner layer is provided with a plurality of belt-shaped elastic bodies, the elastic body is a non-adhesive part that is bonded to the inner liner layer and the other elastic body. And a tubeless tire. 2. The tubeless tire according to claim 1, wherein the elastic body has a slit in a width direction thereof. 3. The tubeless tire according to claim 1, wherein a sealant having a self-sealing action is applied to the elastic body. 4. A method for manufacturing a tubeless tire in which an inner liner layer for maintaining airtightness and an outer layer portion including a tread portion in contact with the ground are sequentially wound around a forming drum on a cylinder, and wherein the inner liner layer is A method for manufacturing a tubeless tire, wherein a plurality of belt-shaped elastic bodies are stretched on the forming drum before winding around the forming drum such that a part of the elastic bodies overlaps the other elastic body. 5. After laminating an inner liner layer for maintaining airtightness and an outer layer portion including a tread portion in contact with the ground and vulcanizing a green tire formed into a tire shape, a belt-shaped elastic body is partially formed. And bonding to the inner surface of the inner liner layer so as to overlap with the other elastic body.