JP2010052260A - Apparatus and method for manufacturing pneumatic tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent air from remaining between tire constituting members by ensuring the air channels upon vulcanization. <P>SOLUTION: Projections having a predetermined shape are formed on the periphery of the rollers of the fold-back finger mechanisms 6, both ends of the carcass ply are folded back so as to be rolled up from the tire diameter direction inside to the outside along the beads with the fold-back rolls, and with the plurality of fold-back finger mechanisms 6 the tire width direction outer side surface of the side rubber 11 is pressed to be bonded to the outer side surface of the carcass ply. When the side rubber 11 is pressed with the fold-back finger mechanisms 6, the projections formed on the periphery of the rollers bite into the outer side surface of the side rubber 11 to lead to the formation of the zigzag grooves 12. The air between the mold and green tire is discharged through these grooves 12 from the vent piece of the mold. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for manufacturing a pneumatic tire by assembling a plurality of tire constituent members, and more particularly, to a pneumatic tire manufacturing apparatus and a manufacturing method for forming a plurality of grooves on the surface of a tire constituent member.

  In general, to form a green tire, a rubber member constituting a plurality of types of belt-like tires (hereinafter referred to as a tire constituent member), for example, an inner liner, a carcass ply, a side rubber, and the like are extruded from an extruder, for example, It is formed in a cylindrical shape by stacking and sticking to the tire forming drum. Subsequently, each tire constituent member formed into a cylindrical shape is shaped into a toroidal shape to form an annular shape (tire shape), and a tread rubber or the like is bonded to the outer peripheral surface thereof to form a green tire.

  When this green tire is vulcanized with a tire vulcanizer, air that has entered between the vulcanization mold (mold) and the green tire may remain, which is caused by the air remaining between the mold and the green tire. The cavities generate bears after vulcanization and reduce tire quality.

Therefore, in order to prevent air from remaining between the mold and the green tire, a plurality of grooves are formed on the surface of the belt-shaped tire constituent member (side member).
That is, by forming a plurality of grooves on the surface of the side member, the air that has entered between the mold and the green tire (side member) when the green tire is set in the mold is used when the green tire is vulcanized. Through the plurality of grooves (air flow paths) formed on the surface, the vent piece (the part for releasing air between the mold provided on the mold and the green tire) provided in the mold is discharged to the outside of the mold, and the residual air Can be prevented.

FIG. 5 is a view for explaining a conventional method for forming the groove on the surface of the side member, FIG. 5A shows a method for forming the groove using a die of an extruder, and FIG. 5B shows a groove using a ridge roll. It is a figure explaining the method of forming.
That is, in the method shown in FIG. 5A, a side member is formed by using a die having a cross-sectional shape so that a groove is formed on the surface of the side member 100 in an extruder for extruding the side member 100 as a tire constituent member. 100 is extruded with an extruder. Thereby, a groove | channel is formed between the protrusions 101 by forming the linear protrusions 101 along the extrusion direction (arrow direction in the figure) on the surface of the side member 100.

  Further, in the method shown in FIG. 5B, the side member 102 immediately after extrusion is conveyed in the direction of the arrow in the figure, and pressed against the surface of the side member 102 while rotating the ridge roll 103 having a plurality of protrusions formed on the outer peripheral surface. A plurality of linear grooves 104 are formed at equal intervals on the surface of the side member 102.

  The side member in which the groove is formed is once wound up on a reel, and then unwound from the reel in a molding process, and is attached to a tire molding drum in combination with other members to form a green tire. At this time, the groove may be crushed by the pressing force of the liner after winding, and the tire component in which the groove is formed is usually half a day in a state of being wound on a reel before being used in a molding process. In addition, since it is stored for one day, there is a problem that the shape of the groove formed in the tire constituent member decreases or disappears in the meantime, and the effect of exhausting the air that has entered between the tire constituent members decreases.

  In order to solve this problem, the applicant of the present invention first, when unrolling the raw rubber member (tire constituent member) extruded from the extruder from the reel, for example, a roller having a large number of protrusions formed on the surface, etc. Then, a large number of grooves are formed on the surface of the raw rubber member, and the raw rubber member having the grooves is wound around the tire molding drum as it is, that is, before the shape of the groove formed in the tire constituent member decreases or disappears in the meantime. A tire manufacturing method for forming a green tire has been proposed (see Patent Document 1).

  However, when the raw rubber member wound around the tire forming drum is formed into a green tire shape, especially when both ends of the raw rubber member are folded back by a stitching roller, the formed groove shape is broken or the groove depth is constant. I found out that it might disappear. In particular, the groove depth may not be constant in the radial direction due to side member diameter growth (from band molding to second molding) during shaping molding. That is, it was found that the groove becomes shallower in the portion where the growth amount is large.

In addition, since the rubber constituting the side portion is contoured in the tire width direction and the gauge in the tire width direction is not constant, if the ridges form grooves with a ridge roll with a constant height, the result is a gauge Compared to the part where the gauge is thin, in the part where the gauge is thick, the protrusion deeply penetrates deeply, so the groove in the part where the gauge is thick becomes deep, and the depth of the groove cannot be formed constant due to the difference in gauge There is also a problem, and as a result, there is a possibility that a problem arises that an air flow path at the time of vulcanization cannot be secured.
JP 2006-142557 A

  The present invention has been made in order to solve the above-described conventional problems, and an object of the present invention is to form a groove having a certain depth on the surface of a tire component member and to prevent the shape of the groove from collapsing. It is to be.

The present invention provides a bead portion having a tire molding drum around which a carcass ply is wound, an expansion means for expanding a central portion of the carcass ply wound around the tire molding drum, and both end portions of the carcass ply expanded at the central portion. And a roller disposed at the tip of a finger that folds from the inner side to the outer side in the tire radial direction and presses the side rubber against the folded carcass ply and presses the side rubber to the outer surface, and the roller is circumferentially disposed on the outer periphery thereof. When the side rubber is pressed against the carcass ply, an air vent groove for vulcanization corresponding to the protrusion is formed on the surface of the side rubber.
Further, the present invention includes a step of winding a carcass ply around a tire molding drum, a step of expanding a central portion of the carcass ply wound around the tire molding drum, and both end portions of the carcass ply in which the central portion is expanded. A step of folding back from the inside in the tire radial direction along the bead portion, a step of pressing side rubber against the folded carcass ply and crimping it to the outer surface, and pressing side rubber against the carcass ply and crimping to the outer surface And a step of forming an air vent groove at the time of vulcanization on the surface of the side rubber by a circumferentially extending protrusion formed on the outer periphery of the pressure-bonding roller.

  According to the present invention, a groove having a certain depth can be formed on the surface of a tire constituent member regardless of the tire size and the member constituting the tire, and the shape of the groove can be prevented from collapsing. It is possible to secure an air flow path at the time of sulfuration to prevent air from remaining between the tire constituent members and to prevent deterioration of the quality of the product tire.

Hereinafter, a manufacturing method and a manufacturing apparatus of a pneumatic tire according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional view of a tire forming drum included in the pneumatic tire manufacturing apparatus according to the present embodiment, and FIG. 1A shows a state in which the tire forming member before expansion of the tire forming drum is not shown. Indicates a state when the tire component is expanded.

  As shown in FIG. 1A, the tire forming drum 1 includes a central shaft 2 and a plurality of pairs of sliders 5 that are spaced apart from each other and moved closer together. On the outer periphery of the slider 5, a plurality of pairs of bead lock devices 10 and folding finger mechanisms 6 that fix and support the bead core are fixed.

  The slider 5 is screw-engaged with a screw shaft 3 provided in a hollow portion in the central shaft 2, and is separated and moved in a laterally symmetrical manner by the rotation of the screw shaft 3, and a pair of bead lock devices 10 mounted on the slider 5 are moved. Displace close to each other.

FIG. 2 is an enlarged top view of the main part of the folding finger mechanism 6 shown in FIG.
The folding finger mechanism 6 folds both ends of the carcass ply wound around the outer periphery of the tire forming drum 1 shown in FIG. 1 so as to be wound around a bead core set in the bead lock device 10. A roller 63 having a predetermined width for pressing a side rubber previously attached to both ends in the tire width direction, a rotating shaft 62 of the roller 63, and one end thereof are pivotally supported by an end portion of the rotating shaft 62. The other end is composed of a finger 61 (not shown) pivotally supported by a cylinder mechanism, for example.

The roller 63 has a zigzag-shaped (broken line-shaped) protrusion 64 formed on the outer periphery thereof along the circumferential direction, and the height of the protrusion 64 is preferably 1 mm to 3 mm.
The roller 63 incorporates a heating means such as a heater (not shown). When the side rubber is pressed by the folding finger mechanism 6, the roller 63 is heated by the heating means. The heated roller 63 transmits heat to the contacting side rubber and heats and softens the rubber, so that the protrusions 64 easily bite into the rubber, and the groove processing can be easily performed.

  When the green tire is formed, as will be described later, when the carcass ply is folded back by the folding finger mechanism 6 using the roller 63 and the side rubber is pressed against the carcass ply on the outer peripheral surface of the roller 63, the surface of the softened side rubber is projected. The strip 64 bites in and forms a zigzag groove for air bleeding corresponding to the shape of the projection 64.

Next, a method for forming a green tire using the tire forming drum 1 will be described with reference to FIG. 1 again.
First, the state shown in FIG. 1A, that is, a single cylindrical body is formed by winding the chafer rubber and the side rubber so that the ends of the tire rubber and the side rubber overlap each other on both ends of a tire component such as a carcass ply formed on the tire molding drum 1. .
An air supply means (not shown), which is an expansion means for expanding the central portion of the cylindrical body, is provided on the inner side of the cylindrical body made of the carcass ply or the like.
Next, a bead member including a bead core and a bead filler is disposed at a position corresponding to the bead lock device 10 on the carcass ply, and the carcass ply and the like are fixed (bead lock).

  Subsequently, as shown in FIG. 1B, the screw shaft 3 is rotated to bring the slider 5 closer to each other, thereby bringing the bead lock device 10 fixed to the slider 5 and the folding finger mechanism 6 closer to each other, and a cylindrical body. The air is supplied from the inside of the carcass ply or the like by an air supply means (not shown) to bulge the carcass ply or the like in a toroidal shape. Thereafter, the finger 61 (see FIG. 2) of the folding finger mechanism 6 is driven inward in the axial direction, for example, by a cylinder mechanism, and the roller 63 is moved outward in the tire radial direction along the outer surface of a toroidal carcass ply or the like. In other words, both ends of the carcass ply are turned from the inner side to the outer side in the tire radial direction, folded back by a large number of rollers 63 so as to be wound around the bead member, and the side rubber is pressed to be pressed against the outer surface of the carcass ply. Then, a green case is formed.

FIG. 3 is a perspective view showing a state in which the side rubbers affixed to both ends of the carcass ply are pressed by the folding finger mechanism 6.
As shown in the figure, the outer side surface of the side rubber 11 in the tire width direction is pressed against the green case by a plurality of folded finger mechanisms 6.

As a result, the protrusion 64 shown in FIG. 2 of the roller 63 bites into the outer surface of the green case, that is, the rubber surface constituting the side rubber 11 by heating and pressing force, as shown in FIG. A zigzag groove 12 having a depth of about 1 mm to 3 mm corresponding to the shape of the protrusion 64 is formed.
By forming the plurality of grooves 12 in accordance with the position of the vent piece (the part for removing air between the mold provided on the mold and the green tire), that is, by forming the end of the groove 12 in the vicinity of the vent piece. When the green tire is vulcanized, air between the mold and the green tire is discharged from the vent piece through the groove 12.

  Finally, another tire constituent member such as tread rubber is attached to the outer peripheral surface of the green case in which the zigzag groove 12 is formed to form a green tire.

  As described above, the groove 12 serving as the air vent channel formed in the side rubber 11 (see FIG. 3) is formed at the end of the tire molding process, that is, when the carcass ply is folded, The green tire can be vulcanized before the shape collapses or disappears, the air entering between the side rubber 11 and the mold is discharged, the occurrence of bears can be prevented, and the quality of the product tire can be prevented from deteriorating. .

Further, since the groove is formed by pressing the protrusion 64 formed on the outer periphery of the roller 63 of the folding finger mechanism 6, the shape of the protrusion 64 is always obtained regardless of the tire size and the type of members constituting the tire. Accordingly, a groove having a certain depth can be formed, and an air flow path during vulcanization can be secured.
Furthermore, since the groove can be formed simultaneously with the folding of the carcass ply, the number of processes is not increased and the working efficiency is not lowered.

  The shape of the protrusion 64 formed on the outer periphery of the roller 63 of the folding finger mechanism 6 shown in FIG. 2 is not only a zigzag shape as in this embodiment, but also a wavy line shape as shown in FIG. As long as the protrusions 64 are continuously formed as shown in FIG. 4B, the shape may be any shape.

It is a schematic sectional drawing of the tire molding drum which the manufacturing apparatus of the pneumatic tire which concerns on this embodiment has. It is a principal part enlarged top view of a folding | turning finger mechanism. It is a perspective view which shows the state which is pressing the side rubber affixed on the both ends of the carcass ply with the return | turnback finger mechanism. It is a figure which shows the example of the shape of the protrusion formed in the roller of a return | turnback finger mechanism. It is a figure explaining the example of the method of forming a groove | channel in the surface of a tire structural member.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Tire shaping drum, 2 ... Center axis, 3 ... Screw axis, 5 ... Slider, 6 ... Folding finger mechanism, 10 ... Bead lock device, 11 ... Side rubber, DESCRIPTION OF SYMBOLS 12 ... Groove, 61 ... Finger, 62 ... Rotating shaft, 63 ... Roller, 64, 101 ... Projection, 100 ... Side member, 102 ... Tire constituent member, 103 ... Ridge roll.

Claims (6)

A tire molding drum around which the carcass ply is wound,
Expansion means for expanding a central portion of the carcass ply wound around the tire molding drum;
The both ends of the carcass ply with the center part expanded are folded back along the bead part from the inner side to the outer side in the tire radial direction, and the side rubber is pressed against the outer side surface by pressing the side rubber against the folded carcass ply. And equipped with
The roller has a circumferentially extending protrusion on its outer periphery, and when pressing the side rubber against the carcass ply, a groove for air venting during vulcanization corresponding to the protrusion is formed on the surface of the side rubber. A pneumatic tire manufacturing apparatus. In the manufacturing apparatus of the pneumatic tire described in Claim 1,
The said roller is provided with the heating means, The manufacturing apparatus of the pneumatic tire characterized by the above-mentioned. In the manufacturing apparatus of the pneumatic tire according to claim 1 or 2,
The protrusion formed on the outer periphery of the roller is composed of a plurality of strips, and the height thereof is 1 mm to 3 mm. Winding a carcass ply around a tire molding drum;
Expanding the central portion of the carcass ply wound around the tire molding drum;
A step of turning back both ends of the carcass ply, the center of which is expanded, from the inside to the outside of the tire in the radial direction along the bead;
Pressing the side rubber against the folded carcass ply and crimping it to the outer surface;
Forming a groove for venting air at the time of vulcanization on the surface of the side rubber by a circumferentially extending protrusion formed on the outer periphery of the pressing roller when the side rubber is pressed against the outer surface of the carcass ply. The manufacturing method of the pneumatic tire characterized by having. In the manufacturing method of the pneumatic tire according to claim 4,
The manufacturing method of the pneumatic tire characterized by having the process of heating the surface of the said side rubber. In the manufacturing method of the pneumatic tire according to claim 4 or 5,
The protrusion formed on the outer periphery of the pressure-bonding roller is composed of a plurality of stripes, and the height thereof is 1 mm to 3 mm.

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