JP2000225654A - Preparation of pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely exhaust air existing between belt-like members such as an inner liner and a carcass ply in a manufacturing process of a pneumatic tire. SOLUTION: At first, an inner liner 10 fed from a servicer is wound on the outer peripheral face of a band drum and then, a carcass ply 18 is wound on the inner liner 10 to form a band. A first drum is inserted into the band and before the first drum is expanded in its diameter, vent holes 30 passing through the carcass ply 18 are formed at approximately equal intervals on at least four positions on the periphery of the central part in the width direction of the carcass ply 18 on the first drum. When the first drum is expanded in its diameter and the band is expanded thereby, air entered between the inner liner 10 and the carcass ply 18 when the band is formed is exhausted outside from the vent holes 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a pneumatic tire, and more particularly, to a method for manufacturing a pneumatic tire, which comprises:
For example, the present invention relates to a method for manufacturing a pneumatic tire capable of reliably discharging air interposed between a carcass ply and an inner liner.

[0002]

2. Description of the Related Art Raw tires are roughly divided into a step of attaching an unvulcanized inner liner on a drum and a step of attaching an unvulcanized carcass ply on the inner liner to form a cylindrical band. Further, it is formed through a step of attaching various tire components such as a belt, a tread rubber, a bead core, a stiffener, and a side rubber.

[0003]

Conventionally, when a carcass ply is stuck on an inner liner, there has been a problem that air enters between the inner liner and the carcass ply, and air enters between the inner liner and the carcass ply. Various proposals have been made to exhaust air.

Conventionally, ridge processing (forming a large number of narrow grooves) on one side of a carcass ply to discharge the air that has entered into the outside via a ridge, or to press a roller or the like from above the carcass to remove air Although some methods have been adopted, some effects have been obtained, but not enough.

In view of the above, an object of the present invention is to provide a method of manufacturing a pneumatic tire that can reliably discharge air interposed between band members such as an inner liner and a carcass ply.

[0006]

According to the first aspect of the present invention, a second belt-shaped member arranged along the tire circumferential direction is attached to a first belt-shaped member arranged along the tire circumferential direction. Attaching, forming a plurality of vent holes in the second belt-shaped tire component in the circumferential direction, expanding the first belt-shaped member and the second belt-shaped member formed into a cylindrical shape, Discharging the air interposed between the first band-shaped member and the second band-shaped member from the vent hole.

In the method for manufacturing a pneumatic tire according to the first aspect, the second belt-shaped member arranged along the tire circumferential direction is attached to the first belt-shaped member arranged along the tire circumferential direction. .

Next, when the first and second belt-shaped members formed in a cylindrical shape are expanded, the inner first band-shaped member is pressed toward the second band-shaped member, so that the first band-shaped member is pressed. The air interposed between the band-shaped member and the second band-shaped member is compressed, flows to the nearest vent hole side, and is discharged from the vent hole to the outside. The air near the end of the band-shaped member flows toward the end of the band-shaped member and is discharged to the outside from the end of the band-shaped member.

The step of forming a plurality of vent holes in the second belt-shaped tire member in the circumferential direction may be performed before or after attaching the first belt-shaped member. It suffices before the second band-shaped member is expanded.

According to a second aspect of the present invention, a first belt-like member arranged along the tire circumferential direction is attached to a drum, and is arranged on the first belt-like member along the tire circumferential direction. Attaching a second band-shaped member to form a cylindrical band, forming a plurality of vent holes in the second band-shaped member in the circumferential direction before or after the formation of the band, A step of expanding a cylindrical band to discharge air interposed between the first band-shaped member and the second band-shaped member from the vent hole, and attaching a tire constituent member on the band after expansion. And a step.

In the method for manufacturing a pneumatic tire according to the second aspect, the first belt-shaped member arranged along the tire circumferential direction is attached on the drum, and thereafter, the first band-shaped member is mounted thereon along the tire circumferential direction. The second band-shaped member to be arranged is attached to form a cylindrical band.

Before or after the formation of the band, a plurality of vent holes are formed in the second band-shaped member in the circumferential direction.

Next, when the cylindrical band is expanded, the inner first band member is pressed toward the second band member, so that the first band member and the second band member are pressed. Is compressed, flows toward the nearest vent hole side, and is discharged from the vent hole to the outside. The air near the end of the band-shaped member flows toward the end of the band-shaped member and is discharged to the outside from the end of the band-shaped member.

After the band is expanded and the air is exhausted,
Another tire constituent member is stuck on the band to form a raw tire.

According to a third aspect of the present invention, in the method for manufacturing a pneumatic tire according to the first or second aspect,
Four or more vent holes are formed in the circumferential direction of the second belt-shaped member.

According to the method of manufacturing a pneumatic tire according to the third aspect, since four or more vent holes are formed in the second belt member in the circumferential direction, the first belt member and the second belt member are formed. The air interposed between the members can be reliably discharged.

The vent holes are preferably formed at equal intervals in the circumferential direction.

According to a fourth aspect of the present invention, in the method of manufacturing a pneumatic tire according to any one of the first to third aspects, the vent hole is formed at a center of the second band-shaped member in the width direction. It is characterized in that it is formed in the vicinity.

The air interposed between the first band member and the second band member in the vicinity of the center in the width direction is difficult to be discharged because the air is separated from both ends of the band member.

In the method for manufacturing a pneumatic tire according to the fourth aspect, since the vent hole is formed near the center in the width direction of the second belt-shaped member, the air interposed near the center in the width direction is reliably discharged. It becomes possible.

According to a fifth aspect of the present invention, in the method for manufacturing a pneumatic tire according to any one of the first to fourth aspects, a plurality of cords are embedded in the second belt-shaped member. The vent hole has an elongated shape along the direction of the cord.

According to the method of manufacturing a pneumatic tire according to the fifth aspect, since the vent hole has a pore shape, the hole area of the vent hole can be sufficiently secured, and the air is easily discharged.

It is possible to form an elongated vent hole along the direction of the cord by piercing the second band-shaped member with an elongated perforating member along the direction of the cord.

Since the perforated member having an elongated shape along the direction of the cord is pierced into the second belt-shaped member, the perforated member can penetrate between the cords while suppressing damage to the cord. If the perforated member is elongated in a direction intersecting the direction of the cord, the cord may be cut when the perforated member is pierced into the second belt-shaped member.

According to a sixth aspect of the present invention, in the method for manufacturing a pneumatic tire according to any one of the first to fifth aspects, the second belt-shaped member includes the first belt-shaped member. A narrow groove is formed on the side surface.

In the pneumatic tire manufacturing method according to the sixth aspect, since the narrow groove is formed on the surface on the side of the first band-shaped member, the gap between the first band-shaped member and the second band-shaped member is provided. The intervening pneumatic tire is easily discharged to the outside from the end portion or the vent hole of the belt-shaped member through the narrow groove.

According to a seventh aspect of the present invention, in the method for manufacturing a pneumatic tire according to any one of the first to sixth aspects, the first belt-shaped member is an inner liner and the second belt-shaped member is an inner liner. Is characterized by being a carcass ply.

In the manufacture of a tire, air is likely to be interposed when the carcass ply is attached to the inner liner. Therefore, vent holes are provided in the carcass ply to discharge air between the inner liner and the carcass ply. And the incidence of defective products can be significantly reduced.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a method for manufacturing a pneumatic tire according to the present invention will be described with reference to FIGS.

As shown in FIG. 1, first, an inner liner 10 supplied from a servicer (not shown) is wound around the outer peripheral surface of a band drum 12.

Next, a nylon chafer 14 and a wire chafer 16 are wound around the band drum 12 near the widthwise end of the inner liner 10 as shown in FIG.

Thereafter, as shown in FIG. 3, a carcass ply 18 is wound on the inner liner 10 to form a cylindrical band 20 on the outer peripheral surface of the band drum 12.

The band 20 is detached from the band drum 12, and as shown in FIG.
2 is inserted.

As shown in FIGS. 5A and 5B, the carcass ply 18 is formed by coating a plurality of cords (steel cords in this embodiment) 24 arranged in parallel with each other with rubber 26. .

Ridges (narrow grooves) 28 parallel to each other are formed at equal intervals on the entire surface of the carcass ply 18 on the inner liner 10 side.

In the present embodiment, before the diameter of the first drum 22 is increased, four or more (preferably six or more, more preferably eight) positions on the circumference of the widthwise central portion of the carcass ply 18 on the first drum 22. As described above, the vent holes 30 penetrating the carcass ply 18 at substantially equal intervals are formed.

The vent hole 30 preferably has an elongated shape along the cord 24 as shown in FIG. 5A, but may have another shape such as a round hole.

The vent hole 30 which is elongated in the cord direction.
As shown in FIG. 5 (A), it can be formed by vertically pushing a perforated member 32 made of a metal plate or the like having a tapered tip into the carcass ply 18 in a direction parallel to the cord 24. .

The length of the vent hole 30 is preferably 2 mm or more in order to easily discharge air.

The thickness of the piercing member 32 is
It is preferably smaller than the inner distance between the cord and the cord 24.

After the vent holes 30 are formed in the carcass ply 18, as shown in FIG. 6, the diameter of the first drum 22 is expanded to expand the vicinity of the center of the band 20 in the width direction. Refine parts.

When the band 20 is expanded, the inner liner 10 presses the carcass ply 18 from the inside, and the width of the air that has entered between the inner liner 10 and the carcass ply 18 when the band 20 is formed. The air near the center in the direction flows toward the nearest vent hole 30 and is discharged to the outside through the vent hole 30, and the air near the end is discharged to the outside from the end.

Since the ridges 28 are formed on the carcass ply 18 on the inner liner 10 side, the air that has entered between the inner liner 10 and the carcass ply 18 will be removed when the ridges 28 are not formed. It is easy to be discharged compared with.

After the band 20 is expanded and the air between the inner liner 10 and the carcass ply 18 is exhausted, as shown in FIG. 7, the bead cores are provided at both ends (only one side is shown in FIG. 7) of the band 20. 34 and the stiffener 36 are inserted.

Thereafter, both ends of the carcass ply 18 are folded inward by a bladder and a push can (not shown), and the side tread 37 is wound as shown in FIG.

Next, the band 20 is attached to a second former 38 as shown in FIG. 9, and the inside is filled with air as shown in FIG. The belt 40 and the top tread 42 are wound around the central portion, and a raw tire 44 as shown in FIG. 11 is completed.

The raw tire 44 is then loaded into a mold (not shown) and vulcanized to produce a product tire, as in the prior art.

When the internal pressure is applied to the raw tire 44 in the mold, the surrounding rubber flows and disappears in the ridge 28 and the vent hole 30.

According to the pneumatic tire manufacturing method of the present embodiment, four or more vent holes 30 are formed in the center portion in the width direction of the carcass ply 18 in the circumferential direction before expansion.
The air that has entered between the inner liner 10 and the carcass ply 18 during expansion can be reliably discharged.

Since the ridge 28 is formed on the carcass ply 18 on the inner liner 10 side, air between the inner liner 10 and the carcass ply 18 is easily discharged.

Further, since the perforated member 32 having an elongated shape is pierced into the carcass ply 18 along the direction of the cord 24, the vent hole 30 having a sufficient hole area is provided.
Through the carcass ply 18.

In the present embodiment, the vent hole 30 is formed in the carcass ply 18 on the first drum 22, but it may be at least any time before the expansion and before the lamination to the inner liner 10.

The number of vent holes formed at the center in the width direction of the carcass ply and the finished green tire (TBR 295)
FIG. 12 shows the result of examining the relationship between the carcass ply (/ 75R225 R194Z) and the amount of air interposed between the inner liner.

As shown in FIG. 12, when six vent holes are formed on the circumference, the air interposed between the carcass ply and the inner liner becomes extremely small. The amount was reduced to zero.

In the present embodiment, the vent hole 30 is formed in the carcass ply 18 in order to discharge the air between the inner liner 10 and the carcass ply 18. However, another ply (for example, a belt or the like) is used. A vent hole 30 may be formed in a member other than the carcass ply 18 in order to discharge air that has entered between the rubber member and the like.

The tip of the piercing member 32 is
It is better to drop the edge so that the cord 24 is hardly damaged when it comes into contact with the wire.

[0057]

According to the method for manufacturing a pneumatic tire of the present invention, air interposed between belt-shaped members such as an inner liner and a carcass ply can be reliably discharged, and a high-quality raw tire can be obtained. The effect is excellent.

[Brief description of the drawings]

FIG. 1 is a perspective view of a band drum around which an inner liner is wound.

FIG. 2 is a perspective view of a band drum around which a nylon chafer and a wire chafer are wound.

FIG. 3 is a perspective view of a band drum around which a carcass ply is wound.

FIG. 4 is a perspective view of a band in which a first drum is inserted.

FIG. 5A is a perspective view of a carcass ply having a vent hole and a perforating member forming a vent hole;
(B) is a top view of the carcass ply in which the vent hole was formed.

FIG. 6 is a perspective view of an expanded band.

FIG. 7 is a sectional view of a band in which a bead core and a stiffener are inserted.

FIG. 8 is a sectional view of a band around which a side tread is wound.

FIG. 9 is a sectional view of a band attached to a second former.

FIG. 10 is a sectional view of a band, a belt, and a top tread of the second former.

FIG. 11 is a sectional view of a completed raw tire.

FIG. 12 is a graph showing a relationship between a vent hole and an air amount between a carcass ply and an inner liner.

[Explanation of symbols]

 10 inner liner 18 carcass ply 20 band 24 cord 30 vent hole

Claims (7)

[Claims] 1. a step of attaching a second band-shaped member arranged along the tire circumferential direction to a first band-shaped member arranged along the tire circumferential direction; Forming a plurality of vent holes in the circumferential direction; expanding the first and second band-shaped members formed into a cylindrical shape, and forming a gap between the first and second band-shaped members. Discharging the air interposed in the vent hole from the vent hole. 2. A first belt-like member arranged along the tire circumferential direction is stuck on a drum, and a second belt-like member placed along the tire circumferential direction is placed on the first belt-like member. A step of forming a cylindrical band by sticking, a step of forming a plurality of vent holes in the second band member before or after the formation of the band in a circumferential direction, and expanding the cylindrical band. Exhausting air interposed between the first band-shaped member and the second band-shaped member from the vent hole, and attaching a tire constituent member on the band after expansion. A method for manufacturing a pneumatic tire, which is a feature. 3. The method for manufacturing a pneumatic tire according to claim 1, wherein four or more vent holes are formed in a circumferential direction of the second belt-shaped member. 4. The method for manufacturing a pneumatic tire according to claim 1, wherein the vent hole is formed near a center in a width direction of the second band-shaped member. . 5. A plurality of cords are buried in the second band-shaped member, and the vent hole has an elongated shape along the direction of the cords. Any one of 4
13. The method for producing a pneumatic tire according to item 13. 6. The device according to claim 1, wherein a narrow groove is formed in a surface of the second band-shaped member on the side of the first band-shaped member. A method for manufacturing the pneumatic tire according to the above. 7. The pneumatic device according to claim 1, wherein the first band-shaped member is an inner liner, and the second band-shaped member is a carcass ply. Tire manufacturing method.