JP7211786B2 - Pneumatic tire manufacturing apparatus and manufacturing method - Google Patents

Description

The present invention relates to a pneumatic tire manufacturing apparatus and manufacturing method.

As a method for manufacturing a pneumatic tire, a ribbon winding method is known in which a tread portion is formed by spirally winding a band-shaped strip rubber around a drum in a partially overlapping manner (see, for example, Patent Document 1).

JP 2009-149206 A

However, in the method of Patent Document 1, air is likely to enter between the wound strip rubber, that is, so-called air entrapment.

An object of the present invention is to effectively prevent air from entering in a pneumatic tire manufacturing apparatus and manufacturing method.

A first aspect of the present invention is a strip rubber feeder having a mouthpiece for extruding a rubber material from the mouthpiece to form a belt-shaped strip rubber, and winding the strip rubber supplied from the strip rubber feeder. A drum and a relative positional relationship between the drum and the strip rubber feeder are changed in the axial direction of the drum so that the strip rubber is spirally wound around the drum in a partially overlapping manner. and an air release groove forming section for forming air release grooves in the surface of the strip rubber pressed against the drum.

According to this configuration, even if air tends to remain in the overlapped portion of the strip rubber, the air can be smoothly discharged through the air release groove. Therefore, air entry can be effectively prevented with a simple structure.

The air release groove forming portion may be a protrusion provided on the inner surface of the mouthpiece.

According to this configuration, the rubber material can be extruded from the mouthpiece to form the band-shaped strip rubber, and at the same time, the air vent groove can be formed. In addition, there is no need for any additional device for forming the air vent groove, and it is only necessary to process the mouthpiece of the existing pneumatic tire manufacturing apparatus to provide the protrusion.

The air vent groove forming section may be arranged between the strip rubber feeder and the drum, and press the outer surface of the strip rubber to form the air vent groove.

According to this configuration, the air release groove can be easily formed by pressing the outer surface of the strip rubber. As the air release groove forming portion, for example, a washer for making a cut in the strip rubber, a transfer roller for transferring the shape of the air release groove, or the like may be employed. In particular, the configuration in which the air release groove is formed by pressing the outer surface of the strip rubber is highly versatile because the shape of the air release groove can be formed in various ways.

For example, the air vent groove forming portion may be arranged to form a linear air vent groove parallel to the supply direction of the strip rubber. Further, the air vent groove forming portion may be arranged to form a streak-like air vent groove perpendicular to the supply direction of the strip rubber. Further, the air release groove forming portion may be arranged and configured so as to form a mesh-like air release groove.

According to these configurations, the air vent groove can be formed in any direction according to the design. In particular, mesh-like air vent grooves can discharge air in various directions, and can prevent air entry more effectively.

The air release groove forming portion may form the air release groove only in the overlapping portions of the strip rubbers.

According to this configuration, air remaining in the overlapped portion of the strip rubber can be removed efficiently. In particular, residual air tends to occur in overlapping portions of the strip rubber. This is because air tends to remain when strip rubbers whose outer surfaces are easily deformed are overlapped. That is, this is a unique problem that arises in the ribbon winding method in which strip rubbers are partially overlapped and wound together, and the above configuration provides an efficient solution to this problem.

The air vent groove forming portion may form an air vent groove at a position closer to the center than both end portions of the strip rubber in the width direction of the strip rubber.

According to this configuration, since the air vent groove is not formed in the vicinity of both ends of the strip rubber in the width direction, the shape of both ends of the strip rubber can be maintained.

In a second aspect of the present invention, a pneumatic tire is manufactured by a ribbon winding method in which a rubber material is extruded from a die to form a belt-shaped strip rubber, and the strip rubber is spirally wound around a drum in a partially overlapping manner. in which an air release groove is formed on the surface of the strip rubber that is pressed against the drum.

According to the present invention, in the pneumatic tire manufacturing apparatus and manufacturing method, air entry can be effectively prevented by forming an air release groove on the surface of the strip rubber that is pressed against the drum.

FIG. 2 is a meridional partial cross-sectional view of the green tire in the first embodiment. FIG. 2 is a meridional half-sectional view of a pneumatic tire obtained by vulcanizing and molding the green tire of FIG. 1 ; FIG. 2 is a schematic configuration diagram of a first sidewall forming apparatus of the pneumatic tire manufacturing apparatus according to the first embodiment. FIG. 4 is a front view of a die provided in the first sidewall forming apparatus according to the first embodiment; FIG. 5 is a cross-sectional view of a strip rubber in which air vent grooves are formed by the base of FIG. 4; A meridional partial sectional view of a tire case. The front view of the mouthpiece with which the 1st sidewall formation apparatus in the modification of 1st Embodiment is provided. FIG. 8 is a cross-sectional view of a strip rubber in which an air vent groove is formed by the mouthpiece of FIG. 7; The schematic block diagram of the 1st sidewall formation apparatus of the manufacturing apparatus of the pneumatic tire which concerns on 2nd Embodiment. The schematic block diagram of the 1st sidewall formation apparatus in the 1st modification of 2nd Embodiment. The schematic block diagram of the 1st sidewall formation apparatus in the 2nd modification of 2nd Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 shows a meridional partial cross-sectional view of a green tire 1 formed by a pneumatic tire manufacturing apparatus (not shown) according to this embodiment. Further, FIG. 2 shows a meridional half-sectional view of a product tire 2 obtained by vulcanizing and molding the green tire 1. As shown in FIG.

The green tire 1 is obtained by integrating the sidewall 4 with the side portion 13 of the tire case 3 .

The tire case 3 consists of a case body 5 and a tread ring 6. - 特許庁

The case body 5 includes a bead core 7, a bead filler 8, a carcass ply 9, an inner liner 10 and a rim strip rubber 11. The case main body 5 has a cylindrical shape as a whole, and includes a crown portion 12 forming an outer peripheral portion and side portions 13 on both sides thereof.

The bead cores 7 are formed by bundling a plurality of wires into a ring shape, and are arranged with a gap left and right (only one bead core 7 is shown in FIG. 1). The bead filler 8 is connected to the bead core 7 and serves to increase the rigidity of this portion. The carcass ply 9 has a toroidal shape and is composed of at least one ply in which a metal carcass cord is covered with rubber. Both sides of the carcass ply 9 are wound around the bead core 7 and the bead filler 8 . The inner liner 10 is arranged inside the carcass ply 9 . A rim strip rubber 11 is arranged outside the bead core 7 and the bead filler 8 . A tread ring 6 is integrated with the crown portion 12 .

The tread ring 6 includes a belt 14 and a belt reinforcing layer 15 from the inner peripheral side, and a tread rubber 16 is arranged on the outer peripheral portion. The tread ring 6 is integrated with the outer peripheral surface of the crown portion 12 of the case body 5 .

The sidewall 4 consists of a first sidewall portion 17 and a second sidewall portion 18 . The first sidewall portion 17 is formed by a first sidewall forming apparatus 19 shown in FIG. The second sidewall portion 18 is formed by a second sidewall forming device 20 (see FIG. 6), although details are not shown.

Referring to FIG. 3, the first sidewall forming device 19 includes a first drum 21, a strip rubber feeder 22, a crimping member 23, a stitcher 41, and the like.

The first drum 21 is formed in a cylindrical shape with the axis O as the center. The outer peripheral surface of the first drum 21 is composed of a radially expandable metal segment, a bladder, or the like. Further, the first drum 21 is rotated counterclockwise in FIG. 3 around the axis O by driving means such as a motor (not shown).

The strip rubber feeder 22 is for feeding a belt-shaped strip rubber 26 and has a mouthpiece 28 at the tip of an extruder 27 . The mouthpiece 28 is formed with an opening 28a through which the strip rubber 26 is extruded. Further, the strip rubber feeder 22 brings the mouthpiece 28 into contact with and separates from the outer peripheral surface of the first drum 21 in the radial direction of the first drum 21 by means of a drive means (moving part) 22a including a conceptually illustrated motor or the like, It reciprocates along the axial direction of the first drum 21 . As a result, the strip rubber 26 is spirally wound around the first drum 21 in a partially overlapping manner. However, the form of the driving means (moving part) 22a is not particularly limited, and the first drum 21 may be moved in the direction of its axis O, that is, the first drum 21 and the strip rubber feeder 22 may move. , relative to each other in the axial center O direction.

Referring to FIG. 4, the cross-sectional shape of opening 28a of base 28 is a flat triangular shape in which the width dimension in the height direction gradually decreases from the central portion in the width direction toward both ends. As a result, the strip rubber 26 extruded from the mouthpiece 28 has a flat shape as a whole, but strictly speaking, it has a triangular cross-sectional shape with the thickest part at the center and gradually becoming thinner toward the ends. In addition, three protrusions (air vent groove forming portions) 28b are provided on the inner surface of the opening 28a of the base 28. As shown in FIG. The protrusion 28b forms three grooves parallel to the feed direction of the strip rubber 26 on the lower surface of the strip rubber 26 (the surface pressed against the drum).

Preferably, as in the present embodiment, the protrusion 28b is provided in a region S1 within half of the full width at the widthwise center of the opening 28a of the mouthpiece 28 . Accordingly, an air vent groove 36 is formed in a region S2 (see FIG. 5) within a half of the entire width of the strip rubber 26 in the width direction of the cross section. In other words, the air vent groove 36 is formed at a position closer to the center than both ends of the strip rubber 26 in the width direction of the strip rubber 26 . As a result, the air vent grooves 36 are not formed in the vicinity of both ends of the strip rubber 26, so that the shape of both ends of the strip rubber 26 can be maintained. The number of protrusions 28b, that is, the number of corresponding air vent grooves 36 is not particularly limited.

Referring to FIG. 3 again, the pressing member 23 has a cylindrical pressing roller 32 rotatably attached to the tip of a piston 31 that can be advanced and retracted by a cylinder 30 about a rotating shaft 32a. The pressing roller 32 is arranged such that the axial direction of its rotating shaft 32 a is parallel to the axial direction of the first drum 21 . By driving the cylinder 30 to advance the piston 31, the strip rubber 26 supplied from the strip rubber feeder 22 can be pressed against the outer surface of the tire case 3 by the outer peripheral surface of the pressing roller 32. It's becoming

The stitcher 41 has substantially the same configuration as the crimping member 23 . The strip rubber 26 attached to the outer surface of the tire case 3 is further pressed by the stitcher 41 to be attached more firmly.

The second sidewall forming device 20 (see FIG. 6) includes a second drum (shaping drum) 40, and the configuration of the first sidewall forming device 19 such as a strip rubber feeder 22, a crimping member 23, and a stitcher 41. It has the same configuration as the parts. The configuration of the second sidewall forming device 20 is substantially the same as the configuration of the first sidewall forming device 19 except for the drum portion, so detailed description and illustration are omitted.

(Method of forming green tire 1)
Next, a method for forming the green tire 1 will be described. The formation of the green tire 1 includes the first and second steps of forming the case body 5, the third step of forming the first sidewall portion 17, the fourth step of forming the tread ring 6, the case body 5 and the first A fifth step of forming the tire case 3 by combining the tread ring 6 with the sidewall portion 17 and a sixth step of forming the second sidewall portion 18 on the tire case 3 are performed. Each of these steps will be described below.

(First step)
First, referring to FIGS. 1 and 2, an inner liner 10 and then a carcass ply 9 are wound around the outer peripheral surface of a band drum (not shown) to form a cylindrical shape. The cylindrical member is transferred from the band drum to the first drum 21 (see FIG. 3).

(Second step)
1 to 3, in the first drum 21, bead cores 7 and bead fillers 8 are arranged on both sides of the carcass ply 9 in the width direction of the cylindrical member including the carcass ply 9 and the inner liner 10. As shown in FIG. Both ends of the carcass ply 9 are folded back (turned up) to cover the outer surfaces of the bead core 7 and the bead filler 8 . The case body 5 is obtained by sticking the rim strip rubber 11 on the region including the folded portion.

(Third step)
Subsequently, as shown in FIG. 3 , strip rubber 26 is supplied to the first drum 21 from the rubber supply portion 22 to form the first sidewall portion 17 on the case main body 5 .

The strip rubber 26 is spirally wound around the first drum 21 . At this time, the crimping member 23 presses the strip rubber 26 against the outer surface of the case body 5 (not shown in FIG. 3). The first winding of the strip rubber 26 is carried out parallel to the rotation direction without moving the first drum 21 in the axial direction. In winding the strip rubber 26 for the second and subsequent rounds, the rubber supply unit 22 is moved toward one side of the first drum 21 in the axial direction at a predetermined feed rate. Here, as shown in FIG. 5, the feed amount per rotation is determined so that the feed amount of the rubber supply unit 22 is about half the width of the strip rubber 26 . That is, in the present embodiment, the strip rubber 26a wound first is spirally wound with the center position C of the strip rubber 26a wound first and one side edge position E of the strip rubber 26b to be wound next aligned with each other. However, the overlapping amount of the strip rubber 26 is not limited to that of this embodiment, and can be changed as appropriate.

The strip rubber 26 wound around the first drum 21 and pressed by the pressing member 23 is sequentially wound so as to partially overlap. When the crimping member 23 is pressed against the strip rubber 26 of the second roll to be wound, the strip rubber 26 of the first roll is crimped. Since the second roll has an air release groove 36 (see FIG. 5) in the overlapping portion with the first roll, the air in the overlapping portion is discharged to the outside through the air release groove 36 and has nowhere to go. It does not cause air pools. Also, even if air remains in the air vent groove 36, it will not remain and can be reliably discharged because the inside of the mold is evacuated during vulcanization molding, which will be described later. After the strip rubber 26 is wound up to the predetermined position in this manner, the tread rubber 16 is wound once around the same circumference in the tire radial direction. Thereby, the first sidewall portion 17 is formed by a so-called ribbon winding method.

(Fourth step)
Apart from the case main body 5 and the first sidewall portion 17, the belt 14 and the belt reinforcing layer 15 are wound around the outer peripheral surface of a belt drum (not shown). A cylindrical tread ring 6 is obtained by forming a tread rubber 16 on the outer peripheral surface of the belt reinforcing layer 15 . The tread rubber 16 can be formed, for example, by a ribbon winding method in which a band-shaped strip rubber 26 is spirally wound multiple times along the tire circumferential direction.

(Fifth step)
The case body 5 having the first sidewall portion 17 formed thereon is transferred from the first drum 21 to the second drum 40 (see FIG. 6), the tread ring 6 is transferred from the belt drum to the second drum 40, and each is transferred to the second drum. 40 on the outer peripheral side. At this time, the tread ring 6 is arranged on the outer peripheral side of the case body 5 . In this state, the case main body 5 is expanded radially outward by the second drum 40 so that the outer peripheral surface thereof is brought into close contact with the inner peripheral surface of the tread ring 6 and deformed. Thereby, as shown in FIG. 6, the tread ring 6 is formed on the case body 5, that is, the tire case 3 is formed, and the main portion of the green tire 1 excluding the second sidewall portion 18 is obtained.

(6th step)
While rotating the second drum 40, the strip rubber 26 is supplied from a rubber supply section (not shown). The method of winding the strip rubber 26 here is substantially the same as in the case of the first sidewall portion 17 . A stitcher is further pressed against the second sidewall portion 18 thus obtained. Thus, the green tire 1 (see FIG. 1) is completed.

The green tire 1 formed by the above steps has the following features.

As shown in FIG. 5, since the strip rubber 26 is formed with the air vent grooves 36, even if air tends to remain in the overlapped portion of the strip rubber 26, the air can be smoothly discharged through the air vent grooves 36. can be done.

Since the projections 28b are formed on the mouthpiece 28, the rubber material can be extruded from the mouthpiece 28 to form the band-shaped strip rubber 26, and at the same time, the air vent grooves 36 can be formed. In addition, no other additional device is required for forming the air vent groove 36, and it is sufficient to process the mouthpiece 28 of the existing pneumatic tire manufacturing device.

As a modification of the present embodiment, the protrusion (air vent groove forming portion) 28b of the mouthpiece 28 may be provided so as to form the air vent groove 36 only in the portion where the strip rubbers 26 overlap each other. In this embodiment, the amount of overlap between the strip rubbers 26 is set to about half the width of the strip rubber 26, so the projections 28b may be formed only in the half area (see FIGS. 7 and 8). .

According to this modification, the air remaining in the overlapped portion of the strip rubber 26 can be removed efficiently. In particular, residual air tends to occur in the overlapped portion of the strip rubber 26 . This is because air tends to remain when strip rubbers whose outer surfaces are easily deformed are overlapped. In other words, this is a peculiar problem that arises in the ribbon winding method in which the strip rubbers 26 are overlapped and wound, and the configuration of this modified example provides an efficient solution to this problem. Note that the configuration of this modified example can also be employed in subsequent embodiments.

(Second embodiment)
In the pneumatic tire manufacturing apparatus of the present embodiment shown in FIG. 9, the method of forming the air release grooves 36 by the first sidewall forming device 19 is different. In this embodiment, the die does not have the protrusion 28b (see FIG. 4) as in the first embodiment, and the first sidewall forming device 19 has a washer. This embodiment is the same as the first embodiment except for the configuration related to the formation of the air release grooves 36 . Therefore, the description of the same parts as the configuration shown in the first embodiment may be omitted.

In this embodiment, a washer (air vent groove forming portion) 50 is provided between the strip rubber feeder 22 and the first drum 21 and cuts the strip rubber 26 in a line-like shape to form the air vent groove 36 . ing. The washer 50 is arranged so as to form a linear air vent groove 36 parallel to the supply direction of the strip rubber 26 . Specifically, the washer 50 is rotatably supported by the support member 51 and arranged to contact the strip rubber 26 , and presses the outer surface of the strip rubber 26 to form the air vent groove 36 . The shape of the air release groove 36 can be substantially the same as that of the first embodiment.

According to this embodiment, the air vent groove 36 can be easily formed by the washer 50 . In particular, the washer 50 has high versatility because the shape of the air vent groove 36 can be formed in various ways.

Referring to FIG. 10, as a first modification of the present embodiment, washer 50 may be arranged to form streaky air vent groove 36 perpendicular to the supply direction of strip rubber 26 . Therefore, the air vent groove 36 is also formed perpendicular to the supply direction of the strip rubber 26 . This modification is effective when it is desired to remove air in the width direction of the strip rubber 26 .

Referring to FIG. 11, as a second modification of the present embodiment, a transfer roller (air release groove forming portion) 52 having a mesh-like outer surface may be used instead of washer 50 . In FIG. 11, a front view of the transfer roller 52 is shown enlarged within a dashed circle. The transfer roller 52 is rotatably supported by the support member 53 and arranged to contact the strip rubber 26 , and presses the outer surface of the strip rubber 26 to form the air vent groove 36 . According to this modification, the mesh-like air release groove 36 can be formed by the transfer roller 52 . Air can be discharged in various directions by the mesh-like air release grooves 36, and the intrusion of air can be prevented more effectively. Although details are not shown, instead of the transfer roller 52, a plurality of washers 50 may be disposed inclined in the supply direction of the strip rubber 26 to form a similar mesh-like air release groove 36. Also, the washer 50 shown in FIGS. 9 and 10 may be replaced with the transfer roller 52 .

As described above, specific embodiments and modifications thereof of the present invention have been described, but the present invention is not limited to the above embodiments, and various changes can be made within the scope of the present invention. For example, an embodiment of the present invention may be an appropriate combination of the contents of individual embodiments and modifications.

In the present embodiment, the air release grooves 36 are formed in the strip rubber 26 forming the sidewall 4, but the target of the strip rubber 26 forming the air release grooves 36 is not particularly limited. For example, similar air release grooves may be formed in the strip rubber 26 forming the tread rubber 16 .

1 … Green tire (pneumatic tire)
2 ... Product tire (pneumatic tire)
DESCRIPTION OF SYMBOLS 3... Tire case 4... Side wall 5... Case body 6... Tread ring 7... Bead core 8... Bead filler 9... Carcass ply 10... Inner liner 11... Rim strip rubber 12... Crown part 13... Side part 14... Belt 15... Belt Reinforcing layer 16... Tread rubber 16a... Side edge 17... First sidewall part 18... Second sidewall part 18a... First winding body 18b... Second winding body 19... First sidewall forming device 20... Second Sidewall forming device 21... First drum (drum)
22... Rubber supply part 22a... Drive means (moving part)
23 -- crimping member 24 -- first grooving member 25 -- second grooving member 26 -- strip rubber 27 -- extruder (strip rubber feeder)
28... Mouthpiece 28a... Opening 28b... Protruding portion (air release groove forming portion)
DESCRIPTION OF SYMBOLS 30... Cylinder 31... Piston 32... Pressure roller 33... First cylinder 34... First piston 35... First serrated roller 36... Air release groove 37... Second cylinder 38... Second piston 39... Second serrated roller 40... Second drum (drum)
41... Stitcher 50... Washer (air release groove forming portion)
51... Supporting member 52... Transfer roller (air release groove forming part)
53 ... support member

Claims (6)

a strip rubber feeder having a mouthpiece for extruding a rubber material from the mouthpiece to form a band-shaped strip rubber;
a drum around which the strip rubber supplied from the strip rubber feeder is wound;
A moving part that changes the relative positional relationship between the drum and the strip rubber feeder in the axial direction of the drum so that the strip rubber is wound around the drum in a partially overlapping spiral. When,
an air release groove forming part that forms an air release groove in the surface of the strip rubber that is pressed against the drum,
The apparatus for manufacturing a pneumatic tire, wherein the air release groove forming section forms the air release grooves only in overlapping portions of the strip rubbers. 2. The pneumatic tire manufacturing apparatus according to claim 1 , wherein the air release groove forming portion is a protrusion provided on the inner surface of the mouthpiece. 2. The pneumatic tire according to claim 1 , wherein the air vent groove forming portion is disposed between the strip rubber feeder and the drum, and forms the air vent groove by pressing the outer surface of the strip rubber. manufacturing device. 4. The pneumatic tire manufacturing apparatus according to claim 3 , wherein said air release groove forming portion is arranged to form a linear air release groove parallel to the supply direction of said strip rubber. 4. The pneumatic tire manufacturing apparatus according to claim 3 , wherein said air release groove forming portion is arranged to form a linear air release groove perpendicular to the supply direction of said strip rubber. A method of manufacturing a pneumatic tire by a ribbon winding method in which a rubber material is extruded from a mouthpiece to form a band-shaped strip rubber, and the strip rubber is spirally wound around a drum in a partially overlapping manner,
A method of manufacturing a pneumatic tire, wherein air release grooves are formed only in overlapping portions of the strip rubber on the surface of the strip rubber pressed against the drum.

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