JP2013146933A - Method for manufacturing pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a pneumatic tire that can facilitate the manufacturing process of a tire.SOLUTION: A manufacturing method of a pneumatic tire includes: a side member molding step ST11 to form a side member that has a bead member, a carcass layer, a sidewall rubber, a rim cushion rubber, and a side inner liner that composes a part of inner liners; and a green tire molding step to form a green tire by arranging a pair of side members, a belt layer, and a tread rubber on a rigid core. Then this green tire is vulcanized and formed.

Description

  The present invention relates to a method for manufacturing a pneumatic tire, and more particularly to a method for manufacturing a pneumatic tire capable of facilitating a tire manufacturing process.

  In recent pneumatic tires, a carcass division structure in which a carcass layer is divided at a tread portion center region has been proposed.

  In a conventional pneumatic tire manufacturing method, first, a pair of bead cores, a pair of bead fillers, a pair of carcass layers, and an inner liner having a single structure are set on a molding drum that can be expanded and contracted in the axial direction. Then, the left and right carcass layers are rolled up to form a cylindrical primary green tire. Next, a belt tread assembly having a belt layer and tread rubber is formed. Then, the primary green tire and the belt / tread assembly are bonded together to form a secondary green tire. Thereafter, the secondary green tire is put into a tire vulcanization mold and vulcanized.

  Here, in the conventional method for manufacturing a pneumatic tire, in the secondary green tire forming process, a shaping bladder expands the primary green tire and attaches it to the inner surface of the belt-tread assembly. Next green tire is formed.

  As a conventional pneumatic tire manufacturing method employing such a configuration, a technique described in Patent Document 1 is known.

JP 2011-20350 A

  By the way, as another conventional method for manufacturing a pneumatic tire, each member is arranged on a rigid core to form a green tire, and the green tire and the rigid core are filled in a tire vulcanization mold. A method of performing a vulcanization molding process is widely known.

  In the manufacturing method of the pneumatic tire using such a rigid core, when forming a green tire on a rigid core, there exists a subject that arrangement | positioning of a carcass layer is not easy. That is, since the tire has a circumferential difference between the bead portion and the tread portion, when the carcass layer is arranged from the bead portion to the tread portion, an excess of the carcass layer is generated at the bead portion and wrinkles. There are challenges.

  For this reason, in a conventional pneumatic tire manufacturing method using a rigid core, the carcass layer is divided into strips and arranged, the carcass cord is knitted on the rigid core, and the carcass layer is formed. It has been adopted.

  This invention is made | formed in view of the above, Comprising: It aims at providing the manufacturing method of the pneumatic tire which can simplify the manufacturing process of a tire.

  In order to achieve the above object, a manufacturing method of a pneumatic tire according to the present invention includes a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, and a pair of rim cushions. A method of manufacturing a pneumatic tire comprising rubber and an inner liner, wherein the bead member, the carcass layer, the sidewall rubber, the rim cushion rubber, and a side inner liner constituting a part of the inner liner A side member molding step for molding a side member having a shape, and a green tire molding step for molding a green tire by arranging the pair of side members, the belt layer, and the tread rubber on a rigid core. And

  The pneumatic tire manufacturing method according to the present invention includes a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner. A side member forming step of forming a side member having a side inner liner that constitutes a part of the bead member, the carcass layer, and the inner liner, And a green tire molding step of molding a green tire by disposing the side member, the sidewall rubber, the rim cushion rubber, the belt layer, and the tread rubber on a rigid core.

  The pneumatic tire manufacturing method according to the present invention includes a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner. A side member molding step of molding a side member having the bead member, the carcass layer, the sidewall rubber, and the rim cushion rubber, the inner liner, and the pair of the tires A pneumatic tire manufacturing method comprising: a green tire molding step of molding a green tire by arranging a side member, the belt layer, and the tread rubber on a rigid core.

  The pneumatic tire manufacturing method according to the present invention includes a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner. A side member molding step for molding the side member having the bead member and the carcass layer, the inner liner, the pair of side members, the sidewall rubber, and the rim. And a green tire molding step of molding a green tire by disposing a cushion rubber, the belt layer, and the tread rubber on a rigid core.

  According to the method for manufacturing a pneumatic tire according to the present invention, a side member having at least a bead member and a carcass layer is assembled in advance, and the side member is disposed on a rigid core to form a green tire. At this time, since the annular side member can be arranged on the rigid core from the side of the rigid core, the carcass layer (side member) can be placed on the rigid core without being affected by the difference in circumferential length between the bead portion and the tread portion. Can be easily arranged. Thereby, there exists an advantage which can simplify the manufacturing process of a tire.

FIG. 1 is a sectional view in the tire meridian direction showing a pneumatic tire according to an embodiment of the present invention. FIG. 2 is a flowchart showing a method for manufacturing the pneumatic tire shown in FIG. FIG. 3 is an explanatory view showing a method for manufacturing the pneumatic tire shown in FIG. 1. FIG. 4 is an explanatory view showing a method for manufacturing the pneumatic tire shown in FIG. 1. FIG. 5 is an explanatory view showing a method for manufacturing the pneumatic tire shown in FIG. 1. FIG. 6 is an explanatory diagram showing a method for manufacturing the pneumatic tire depicted in FIG. 1. FIG. 7 is an explanatory view showing a method for manufacturing the pneumatic tire shown in FIG. 1. FIG. 8 is an explanatory view showing a method for manufacturing the pneumatic tire shown in FIG. 1. FIG. 9 is an explanatory view showing the effect of the method for manufacturing the pneumatic tire shown in FIG. 1. FIG. 10 is an explanatory view showing an inner liner of the pneumatic tire shown in FIG. FIG. 11 is an explanatory view showing a modification of the inner liner shown in FIG. FIG. 12 is an explanatory view showing a modified example of the inner liner shown in FIG. FIG. 13 is an explanatory view showing a modification of the method for manufacturing the pneumatic tire shown in FIG. FIG. 14 is an explanatory view showing a modification of the manufacturing method of the pneumatic tire shown in FIG. FIG. 15 is an explanatory view showing a modified example of the manufacturing method of the pneumatic tire shown in FIG. FIG. 16 is an explanatory view showing a modified example of the manufacturing method of the pneumatic tire shown in FIG. FIG. 17 is an explanatory view showing a modification of the method for manufacturing the pneumatic tire shown in FIG. FIG. 18 is an explanatory view showing a modification of the method for manufacturing the pneumatic tire depicted in FIG. 2. FIG. 19 is an explanatory view showing a modification of the method for manufacturing the pneumatic tire shown in FIG. FIG. 20 is an explanatory view showing a modification of the method for manufacturing the pneumatic tire shown in FIG. FIG. 21 is an explanatory view showing a modification of the method for manufacturing the pneumatic tire depicted in FIG. 2. FIG. 22 is an explanatory diagram showing a modification of the method for manufacturing the pneumatic tire depicted in FIG. 2. FIG. 23 is an explanatory view showing a modification of the manufacturing method of the pneumatic tire shown in FIG. FIG. 24 is an explanatory view showing a modification of the manufacturing method of the pneumatic tire shown in FIG. FIG. 25 is an explanatory diagram showing a modification of the method for manufacturing the pneumatic tire depicted in FIG. 21. FIG. 26 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 27 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 28 is an explanatory view illustrating a modified example of the pneumatic tire depicted in FIG. 1. FIG. 29 is an explanatory diagram illustrating a modification of the pneumatic tire depicted in FIG. 1. FIG. 30 is an explanatory view showing a modified example of the pneumatic tire depicted in FIG. 1. FIG. 31 is an explanatory diagram showing a modified example of the pneumatic tire depicted in FIG. 1. FIG. 32 is a chart showing the results of performance tests of the pneumatic tire manufacturing method according to the embodiment of the present invention.

  Hereinafter, the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments. Further, the constituent elements of this embodiment include those that can be replaced while maintaining the identity of the invention and that are obvious for replacement. In addition, a plurality of modifications described in this embodiment can be arbitrarily combined within a range obvious to those skilled in the art.

[Pneumatic tire]
FIG. 1 is a sectional view in the tire meridian direction showing a pneumatic tire 1 according to an embodiment of the present invention. FIG. 1 shows a radial tire for a passenger car having a carcass division structure as an example of the pneumatic tire 1. Reference sign CL is a tire equator plane.

  The pneumatic tire 1 includes a pair of bead cores 11, 11, a pair of bead fillers 12, 12, a pair of carcass layers 13, 13, a belt layer 14, a tread rubber 15, a pair of sidewall rubbers 16, 16 and a pair of rim cushion rubbers 17 and 17 (see FIG. 1).

  The pair of bead cores 11 and 11 has an annular structure and constitutes the core of the left and right bead portions. The pair of bead fillers 12 and 12 are disposed on the outer periphery in the tire radial direction of the pair of bead cores 11 and 11 to reinforce the bead portion.

  The pair of carcass layers 13 and 13 has a two-layer structure formed by laminating two carcass plies 131 and 132, respectively, and is arranged from the left and right bead cores 11 and 11 to the tread portion to form a tire skeleton. Configure. Further, the end portion of each carcass layer 13 on the inner side in the tire radial direction is wound back and locked to the outer side in the tire width direction so as to wrap the bead core 11 and the bead filler 12. Further, the left and right carcass layers 13 are arranged separately in the tire width direction in the tread portion center region (carcass division structure). The carcass plies 131 and 132 are formed by rolling a plurality of carcass cords made of steel or an organic fiber material (for example, nylon, polyester, rayon, etc.) with a coat rubber.

  In such a carcass division structure, a hollow portion (a region where the carcass layers 13 and 13 are not disposed) is formed in the tread center region. At this time, the tension of the tire in the hollow portion is carried by the belt layer 14, and the rigidity in the left and right sidewall portions is ensured by the left and right carcass layers 13, 13, respectively. As a result, the weight of the tire can be reduced while maintaining the internal pressure holding capability of the tire and the rigidity of the sidewall portion.

  The belt layer 14 is formed by laminating a pair of cross belts 141 and 142, a belt cover 143, and a pair of edge covers 144, and is arranged around the outer periphery of the carcass layer 13. The pair of cross belts 141 and 142 is formed by rolling a plurality of belt cords made of steel or organic fiber material with a coating rubber, and having a belt angle of 10 [deg] or more and 30 [deg] or less in absolute value. Have. Further, the pair of cross belts 141 and 142 have belt angles with different signs from each other (inclination angle of the fiber direction of the belt cord with respect to the tire circumferential direction), and are laminated so that the fiber directions of the belt cords cross each other. (Cross ply structure). The belt cover 143 is formed by rolling a plurality of belt cords made of steel or organic fiber material with a coat rubber, and has a belt angle of 10 [deg] or more and 45 [deg] or less in absolute value. Further, the belt cover 143 is disposed so as to be laminated on the outer side in the tire radial direction of the cross belts 141 and 142. The pair of edge covers 144 and 144 are disposed on the outer side in the tire radial direction of the belt cover 143 and on the left and right edge portions.

  The tread rubber 15 is disposed on the outer circumference in the tire radial direction of the carcass layers 13 and 13 and the belt layer 14 to constitute a tread portion of the tire. The pair of side wall rubbers 16 and 16 are respectively arranged on the outer side in the tire width direction of the carcass layer 13 to constitute left and right side wall portions. The pair of rim cushion rubbers 17 and 17 are arranged on the outer sides in the tire width direction of the left and right bead cores 11 and 11 and the bead fillers 12 and 12, respectively, and constitute left and right bead portions.

  In the configuration of FIG. 1, as described above, the pneumatic tire 1 includes the pair of bead cores 11, 11, the pair of bead fillers 12, 12, and the pair of sidewall rubbers 16, 16. However, the present invention is not limited to this, and the pneumatic tire 1 may include a plurality of pairs of bead cores 11 and 11, a plurality of pairs of bead fillers 12 and 12, or a plurality of pairs of sidewall rubbers 16 and 16 (not shown). . For example, the structure by which the bead filler 12 is arrange | positioned 2 each on the tire right and left is mentioned.

  In the configuration of FIG. 1, the left and right bead fillers 12 and 12 may be omitted (not shown). Therefore, the structure which does not have the bead filler 12 is assumed. In this embodiment, the configuration having both the bead core 11 and the bead filler 12 (see FIG. 1), and the configuration having only the bead core 11 by omitting the bead filler 12 (not shown) are collectively referred to as a bead member. .

[Inner liner]
The pneumatic tire 1 has an inner liner 18 (see FIG. 1). The inner liner 18 is disposed so as to cover the left and right carcass layers 13 and 13 and the belt layer 14 on the inner peripheral surface of the tire, thereby suppressing oxidation due to exposure of these and preventing leakage of air filled in the tire. To do.

  For example, in the configuration of FIG. 1, the inner liner 18 includes a pair of side inner liners 181 and 181 and an under-belt inner liner 182, which are bonded to each other while being wrapped. The pair of side inner liners 181 and 181 are belt-shaped rubber sheets, and are arranged so as to wrap around the tire along the left and right carcass layers 13 and 13 and to wrap both ends in the circumferential direction. The under-belt inner liner 182 is a belt-like rubber sheet, and is arranged so as to go around the tire along the belt layer 14 and wrap both ends in the circumferential direction. Further, the left and right side inner liners 181 and 181 and the belt lower inner liner 182 are disposed so as to wrap edges in the width direction. Thereby, a toroidal rubber sheet is formed, and the inner peripheral surface of the carcass layer 13 and the inner peripheral surface of the belt layer 14 are covered without a gap.

  The inner liner 18 may have an adhesive tie rubber (not shown). For example, tie rubber is laminated and integrated on the pair of side inner liners 181 and 181 and the belt lower inner liner 182. The side inner liner 181 adheres to the carcass layer 13 via a tie rubber, and the lower belt inner liner 182 adheres to the belt layer 14 via a tie rubber. Thereby, the adhesion state of the inner liner 18 is ensured appropriately.

[Pneumatic tire manufacturing method]
FIG. 2 is a flowchart showing a method for manufacturing the pneumatic tire 1 shown in FIG. 3-8 is explanatory drawing which shows the manufacturing method of the pneumatic tire 1 described in FIG. FIG. 9 is an explanatory view showing the effect of the manufacturing method of the pneumatic tire 1 shown in FIG. In these drawings, FIG. 3 shows a molded single side member X, and FIG. 4 schematically shows a molding process of the side member X. FIG. 5 shows a molding process of the green tire Z. FIG. 6 shows a state when the side member X is installed, and FIGS. 7 and 8 show a molded green tire Z. FIG. 9 (a) and 9 (b) show two types of pneumatic tires 1A and 1B having the same cross-sectional height SH and different tread widths TW1 and TW2 and tire peripheral lengths TP1 and TP2, respectively. Show.

  The pneumatic tire 1 is manufactured as follows (see FIG. 2).

  In step ST11, a pair of side members X, X is formed (side member forming step ST11). As shown in FIGS. 2 and 3, one side member X includes one bead core 11, one bead filler 12, one carcass layer 13 (two stacked carcass plies 131 and 132), One side wall rubber 16, one rim cushion rubber 17, and one side inner liner 181 constituting the inner liner 18 are configured.

  In this step ST11, as shown in FIG. 4, each member is set to the side member forming drum 21. At this time, the bead core 11 is held at a predetermined position on the side of the side member molding drum 21 by a holding device (not shown), and the carcass layer 13 and the side inner liner 181 are placed on the side member molding drum 21 by the member pressing device 22. Retained. Then, the turn-up bladder 23 is used to wind up the carcass layer 13 and the sidewall rubber 16 so as to wrap the bead core 11 and the bead filler 12. And these members are crimped | bonded by the turnup bladder 23, and a uniform cross section and the cyclic | annular side member X are shape | molded. Further, the pair of left and right side members X and X are formed by the same process.

  In addition, as the side member shaping | molding drum 21, the holding device (illustration omitted), and the member pressing device 22, the structure of the existing primary green tire shaping | molding drum (illustration omitted) can be diverted, for example. In forming the side member X, a member in which the side wall rubber 16 and the rim cushion rubber 17 are integrated in advance may be used (see FIG. 4A).

  In step ST12, the green tire Z is molded on the rigid core 24 (green tire molding step ST12). 2 and 5, the green tire Z includes a pair of side members X and X, a belt layer 14 (a pair of cross belts 141 and 142, a belt cover 143, and a pair of edge covers 144 and 144), A tread rubber 15 and a belt lower inner liner 182 constituting the inner liner 18 are formed.

  In this step ST12, a pre-assembled rigid core 24 is used. The rigid core 24 has an outer shape for forming a tire inner surface shape during tire vulcanization molding. An existing configuration can be adopted as the rigid core 24. And the side members X and X are arrange | positioned at the right and left of this rigid core 24, respectively (refer Fig.5 (a)). Thereafter, the belt layer 14, the tread rubber 15, and the belt inner liner 182 are disposed, and the green tire Z (see FIG. 7) is formed on the rigid core 24 (see FIG. 5B).

  Here, the process of arrange | positioning the side member X to the rigid core 24 can be performed like FIG. 6, for example. First, the side member X is set and gripped on the gripping devices 25 and 26 (see FIG. 6A). Next, the gripping device 25 is driven to increase the diameter of the end portion of the side member X on the tread side (see FIG. 6B). Thereafter, the gripping devices 25, 26 move in the axial direction of the rigid core 24 to fit the side member X to the rigid core 24 from the side of the rigid core 24, and end portions of the side members X on the tread side Is arranged along the side of the rigid core 24 (see FIG. 6C). In this state, the gripping devices 26 and 26 on the bead side hold the left and right side members X and X on the rigid core 24.

  Further, in the green tire Z, as shown in FIGS. 7 and 8, the side inner liners 181 and 181 of the left and right side members X and X and the belt inner liner 182 are mutually wrapped in the tire width direction. Be placed. At this time, the wrap width W1 is set in a range of 1 [mm] ≦ W1 ≦ 10 [mm]. As a result, the bonding margin between the left and right side inner liners 181 and 181 and the lower belt inner liner 182 is optimized, and the inner peripheral surface of the carcass layers 13 and 13 and the inner peripheral surface of the belt layer 14 are covered without any gaps. Is done. Further, by leaving the bonding allowance as 1 [mm] ≦ W1, the opening of the lap portion between the side inner liners 181 and 181 and the belt inner liner 182 during tire vulcanization is appropriately prevented. Further, by setting W1 ≦ 10 [mm], it is possible to reduce the rubber volume of the inner liner and prevent damage to the core or mold during vulcanization molding due to the non-compression characteristics of the rubber.

  Moreover, in the green tire Z, as shown in FIG. 7, the carcass layers 13 and 13 and the belt layer 14 are disposed so as to be wrapped in the tire width direction. At this time, the wrap width W2 is set in a range of 5 [mm] ≦ W2, preferably in a range of 25 [mm] ≦ W2. Thereby, the internal pressure holding | maintenance capability of a tire and the rigidity of a sidewall part are maintained. The upper limit of the wrap width W2 is preferably in the range of W2 ≦ 0.1 × Wb [mm] with reference to the width Wb of the wide cross belt 141 in the tire width direction. As a result, the tire weight can be effectively reduced by the carcass division structure. The lap width W2 is the tire width of the innermost end of the carcass layer 13 (out of the two carcass plies 131 and 132) in the tire width direction and the widest cross belt 141 that forms the belt layer 14. It is measured as the distance in the tire width direction from the outer end in the direction.

  Further, in the green tire Z, as shown in FIG. 8, both end portions of the inner liner 18 are arranged so as to wrap in the tire circumferential direction. At this time, the wrap width W3 is set in a range of 0 [mm] ≦ W3 ≦ 3 [mm]. Thereby, the inner peripheral surface of the carcass layer 13 and the inner peripheral surface of the belt layer 14 are appropriately covered without a gap.

  In step ST13, a vulcanization molding process of the green tire Z is performed (tire vulcanization molding step ST13). In this step ST13, the tire vulcanization mold is filled with the green tire Z installed in the rigid core 24 (not shown). Next, the tire vulcanization mold is heated, and the tire molding mold of the tire vulcanization mold is pressurized and closed, whereby the green tire Z is pressed between the tire molding mold of the tire vulcanization mold and the rigid core. . In addition, when the green tire Z is heated, the rubber molecules and sulfur molecules in the tread portion are bonded and vulcanized. At this time, the shape of the tire molding die is transferred to the tread surface of the green tire Z, and the tire tread pattern is molded. Then, the molded tire is pulled out from the tire vulcanization mold.

  In the configuration shown in FIG. 2, as described above, the tire vulcanization mold is filled with the green tire Z in a state where the green tire Z is installed on the rigid core 24 and the vulcanization molding process is performed. However, the present invention is not limited thereto, and the green tire Z may be removed from the rigid core 24 and vulcanized using a bladder (not shown). Since the green tire Z is integrated by the crimping force of the carcass layers 13 and 13 and the belt layer 14, vulcanization molding using such a bladder is possible.

  In the method for manufacturing the pneumatic tire 1, the side member X (see FIG. 3) is assembled in advance, and the side member X is disposed on the rigid core 24 to form the green tire Z (see FIG. 5). At this time, since the annular side member X can be disposed on the rigid core 24 from the side of the rigid core 24 (see FIG. 6), the carcass layer is not affected by the circumferential length difference between the bead portion and the tread portion. 13 (side member X) can be easily disposed on the rigid core 24.

  Moreover, in the manufacturing method of this pneumatic tire 1, for example, when manufacturing two types of pneumatic tires 1A and 1B having the same cross-sectional height SH and mutually different tread widths TW1 and TW2 as shown in FIG. It is beneficial. That is, in the configuration of FIG. 2, the pneumatic tire 1 includes left and right carcass layers 13 and 13 having a divided structure and left and right side inner liners 181 and 181 having a divided structure (see FIG. 1). The side members X and X can be independently molded in a state of being separated from each other (see, for example, FIGS. 3 and 4). Then, the side member X can be shared in two types of pneumatic tires 1A and 1B (see FIG. 9) having the same cross-sectional height SH and different tire peripheral lengths TP1 and TP2. Thereby, the inventory of semi-finished products can be reduced.

  In the pneumatic tire 1 of FIG. 1, as shown in FIG. 10, the side inner liners 181 and 181 of the left and right side members X and X and the belt lower inner liner 182 of the belt / tread assembly Y are tires. They are arranged so as to wrap in the width direction. Further, the wrap width W1 is optimized within a predetermined range. Here, in the configuration of FIG. 10, the side inner liner 181 and the under-belt inner liner 182 have edges having a rectangular cross-sectional shape (bat shape), and the edges are arranged so as to be overlapped with each other.

  However, the present invention is not limited to this, and as shown in FIG. 11, the side inner liner 181 and the lower belt inner liner 182 have edges with cross-sectional shapes (butt splice shapes) cut out at angles, and the edges are joined. You may wrap and arrange | position so that it may match. At this time, as shown in FIG. 12, the edge portion of the side inner liner 181 and the edge portion of the belt inner liner 182 may be overlapped with each other while being displaced. Thus, the inner peripheral surface of the belt layer 14 is covered without a gap by arranging the side inner liner 181 and the belt lower inner liner 182 so as to wrap. Thereby, the oxidation of the belt layer 14 is suppressed and the air tightness of the tire is ensured. 11 and 12 is preferable in that the material cost of the tire can be reduced because the amount of the inner liner member used can be reduced as compared with the configuration of FIG. Furthermore, the configuration of FIG. 11 is preferable in that the unevenness of the tire inner peripheral surface can be reduced, and the appearance of the tire can be improved.

  In addition, the wrap width W1 is set by arranging the edge end surfaces of the left and right side inner liners 181 and 181 and the edge end surfaces of the belt lower inner liner 182 in contact with each other over the entire circumference of the tire. W1 = 0 [mm] can be set (not shown). However, in order to reliably prevent the butted portion from opening, it is preferable that the wrap width W1 is 1 [mm] ≦ W1.

  Further, the lap portions and the lap width W3 (see FIG. 8) at both ends of the inner liner 18 in the tire circumferential direction are also configured as shown in FIGS. 10 to 12 (the bat shape shown in FIG. 10 or the butt splice shape shown in FIGS. 1 and 12). The structure in which the end portions of each other are wrapped together can be similarly employed.

[Modification]
FIGS. 13-18 is explanatory drawing which shows the modification of the manufacturing method of the pneumatic tire 1 described in FIG. In these drawings, FIG. 13 shows a flowchart of a method for manufacturing the pneumatic tire 1. FIG. 14 shows a single side member X. 15 to 18 show the molding process of the side member X.

  2 and 3, the side member X is molded including the sidewall rubber 16 and the rim cushion rubber 17 in the side member molding step ST11.

  However, the present invention is not limited to this, and as shown in FIGS. 13 and 14, one side member X includes one bead core 11, one bead filler 12, and one carcass layer 13 (carcass plies 131 and 132). One side inner liner 181 may be included. At this time, similarly to the configuration of FIG. 4, each member can be pressure-bonded by the turn-up bladder 23 to form the side member X (see FIG. 15). Further, in the green tire molding step ST22, the pair of side members X, X, the belt layer 14, the tread rubber 15, the left and right side wall rubbers 16, 16 and the left and right rim cushion rubbers 17, 17 are in a rigid body. The green tire Z (see FIG. 7) is formed by assembling on the child 24. Even with this configuration, the green tire Z can be formed appropriately.

  In the configuration in which the side member X includes the chafer 19, as shown in FIG. 16, the side member X may be molded by pressing the chafer 19 and another member in the side member molding step ST21.

  In the pneumatic tire 1 shown in FIG. 1, the carcass layer 13 has a two-layer structure in which two carcass plies 131 and 132 are laminated. However, the present invention is not limited to this, and the carcass layer 13 has a single-layer structure or a three-layer structure. You may have the above multilayered structure (illustration omitted). In such a case, one side member X has a single carcass ply 131.

  As described above, the configuration of the side member X can be appropriately changed depending on the specification of the tire. One side member X may be configured to include at least one bead core 11, one bead filler 12, and one carcass ply 131 (see FIGS. 13 and 14).

  In the configuration of FIG. 4, the side member X is formed by using the side member forming drum 21, the member pressing device 22, and the turn-up bladder 23. However, the present invention is not limited to this, and the side member X may be formed by using a wrapping bladder 27 as shown in FIG. The wrapping bladder 27 winds up the carcass layer 13 and the side inner liner 181 from the outside so that the carcass layer 13 and the side inner liner 181 wrap around the bead core 11 and the bead filler 12, and wraps each member from the surroundings and presses the members. It has a structure.

  In addition, as shown in FIG. 18, the carcass layer 13 and the side inner liner 181 may be wound around the bead core 11 and the bead filler 12 using a roller 28. Specifically, the roller 28 is composed of a pair of roll-shaped members whose opening angles are narrowed in the circumferential direction, and each member constituting the side member X is set on the roller 28 and rotated in the circumferential direction. The carcass layer 13 and the side inner liner 181 are wound around the bead core 11 and the bead filler 12. As such a roller 28, for example, an existing molding machine for winding a bead cover (not shown) around the bead portion may be employed.

  19 and 20 are explanatory views showing a modification of the method for manufacturing the pneumatic tire 1 shown in FIG. These drawings show a process of installing the side member X on the rigid core 24.

  In the configuration of FIG. 6, the gripping devices 25 and 26 are arranged to be fitted to the side portion of the rigid core 24 by expanding the diameter while gripping the side member X. However, the present invention is not limited to this, and the side member X may be disposed as follows with respect to the rigid core 24 (see FIGS. 19 and 20).

  In the configuration of FIG. 19, the gripping device 26 grips the bead portion of the side member X with the side member X folded back outward in the tire width direction, moves in the axial direction, and moves the side member X of the rigid core 24. It arrange | positions to a side (refer Fig.19 (a)). The gripping device 26 holds the side member X in a state where the bead portion of the side member X is in contact with the side surface of the rigid core 24. Next, the roller 29 raises and reverses the side member X, thereby arranging the side member X along the rigid core 24 (see FIG. 19B).

  In the configuration of FIG. 20, a bladder 30 is used instead of the roller 29. Thus, a reversing device such as the roller 29 or the bladder 30 may be used to install the side member X on the rigid core 24.

  FIGS. 21-23 is explanatory drawing which shows the modification of the manufacturing method of the pneumatic tire 1 described in FIG. In these drawings, FIG. 21 shows a flowchart of a method for manufacturing the pneumatic tire 1. FIG. 22 shows a single side member X. FIG. 23 shows a molding process of the side member X.

  In the pneumatic tire 1 of FIG. 1, the inner liner 18 has a divided structure, and includes left and right side inner liners 181 and 181 and a belt lower inner liner 182. In the method for manufacturing the pneumatic tire 1, the side member X includes the side inner liner 181 as shown in FIG. 2.

  However, the inner liner 18 having a single structure extending over the left and right sidewall portions is not limited thereto. Such an inner liner 18 is widely used in existing pneumatic tires.

  For example, in the configuration of FIGS. 21 and 22, one side member X includes one bead core 11, one bead filler 12, one carcass layer 13 (carcass plies 131 and 132), one side wall rubber 16 and 1. It is composed of two rim cushion rubbers 17 and does not include an inner liner 18. In addition, according to the specification of a tire, the side member X may be comprised including other members, such as the chafer 19 (refer FIG. 16).

  In the configuration of FIG. 21, first, the side member X is formed (step ST31). At this time, the configurations of FIGS. 15 to 18 may be employed. Next, the pair of side members X, X, the belt layer 14, the tread rubber 15, and the single-layer inner liner 18 are disposed on the rigid core 24 to form the green tire Z (step) ST32). Specifically, first, as shown in FIG. 23, the inner liner 18 is disposed on the rigid core 24 (see FIG. 23A). At this time, as an arrangement method of the inner liner 18, known methods such as a strip wind method and a short high tension method can be employed. Next, the left and right side members X, X are disposed on the rigid core 24 (see FIG. 23B). As an arrangement method of the side member X, the configuration shown in FIG. 6, FIG. 19 or FIG. 20 can be adopted. Thereafter, the belt layer 14 and the tread rubber 15 are disposed on the rigid core 24, and the green tire Z (not shown) is molded (step ST32).

  24 and 25 are explanatory views showing a modification of the method for manufacturing the pneumatic tire 1 shown in FIG. In these drawings, FIG. 24 shows a flowchart of the manufacturing method of the pneumatic tire 1. FIG. 25 shows a single side member X.

  21 and 22, the side member X is molded including the sidewall rubber 16 and the rim cushion rubber 17 in the side member molding step ST31.

  However, not limited to this, as shown in FIGS. 24 and 25, one side member X may be composed of one bead core 11, one bead filler 12, and one carcass layer 13. In the green tire molding step ST42, the pair of side members X, X, the belt layer 14, the tread rubber 15, the left and right sidewall rubbers 16, 16 and the left and right rim cushion rubbers 17, 17 are single. The inner liner 18 having a structure is disposed on the rigid core 24, and a green tire Z (not shown) is formed. Even with this configuration, the green tire Z can be formed appropriately.

  26-31 is explanatory drawing which shows the modification of the pneumatic tire 1 described in FIG. In these drawings, FIG. 26 schematically shows an arrangement configuration of the carcass layer 13 and the inner liner 18 of the pneumatic tire 1 shown in FIG. 1, and FIGS. 27 to 31 show modifications thereof.

  As shown in FIG. 26, the pneumatic tire 1 in FIG. 1 has a carcass division structure in which a pair of carcass layers 13 and 13 are arranged separately on the left and right sides of the tire. Thereby, weight reduction of the tire is achieved, ensuring tire rigidity. The inner liner 18 includes a pair of side inner liners 181 and 181 and a belt lower inner liner 182, and these end portions are bonded to each other while being overlapped with each other in the tire width direction (see FIG. 8). Thereby, the inner liner 18 covers the inner peripheral surface of the carcass layers 13 and 13 and the inner peripheral surface of the belt layer 14 without a gap.

  On the other hand, in the modification of FIG. 27, the pneumatic tire 1 has an intermediate carcass ply 133 in the configuration of FIG. The intermediate carcass ply 133 is disposed on the inner side in the tire radial direction of the belt layer 14, and is disposed so as to wrap on the left and right carcass layers 13, 13 at the left and right edges, respectively. Thereby, the intermediate carcass ply 133 fills the hollow portion between the left and right carcass layers 13 and 13, and the rigidity of the tire is reinforced. The intermediate carcass ply 133 is disposed on the rigid core 24 at, for example, the green tire molding step ST12 (ST22, ST32, ST42). At this time, the intermediate carcass ply 133 and the left and right carcass layers 13 and 13 are arranged so as to be overlapped with each other (see FIG. 27).

  Further, in the modification of FIG. 28, in the configuration of FIG. 26, the inner liner 18 has a pair of side inner liners 181 and 181, and these side inner liners 181 and 181 extend to the center region of the tread portion. Wrapped to be placed. For this reason, the belt lower inner liner 182 (see FIG. 26) is omitted. Even in such a configuration, the inner peripheral surfaces of the carcass layers 13 and 13 and the inner peripheral surface of the belt layer 14 are covered without a gap.

  At this time, it is preferable that the wrap width W4 of the left and right side inner liners 181 and 181 is set in a range of 2 [mm] ≦ W4 ≦ 10 [mm]. Thereby, the inner peripheral surface of the carcass layer 13 and the inner peripheral surface of the belt layer 14 are appropriately covered without a gap. Moreover, opening of the lap | wrap part of the side inner liners 181 and 181 at the time of tire vulcanization is prevented by being 2 [mm] <= W4. Further, by satisfying W4 ≦ 10 [mm], it is possible to reduce the rubber volume of the inner liner and prevent the core or the mold from being damaged during vulcanization molding due to the non-compression characteristics of the rubber. The lap width W4 is measured for the green tire Z after shaping. Further, as the wrap structure of the left and right side inner liners 181 and 181, the configuration shown in FIGS. 10 to 12 (the structure in which the ends of the bat shape of FIG. 10 or the butt splice shape of FIGS. 1 and 12 are mutually wrapped) is used. It can be employed as well.

  In the modification of FIG. 29, in the configuration of FIG. 26, the pair of carcass layers 13 and 13 extend to the center region of the tread portion and are arranged so as to wrap with each other. Thereby, the structural strength of the tire is reinforced.

  Further, in the modification of FIG. 30, in the modification of FIG. 29, the left and right side inner liners 181 and 181 are further extended to the center area of the tread portion and arranged so as to overlap each other. Thereby, the inner peripheral surfaces of the carcass layers 13 and 13 are covered without a gap.

  In the modification of FIG. 31, the belt lower inner liner 182 is omitted in the configuration of FIG. In such a configuration, since the belt layer 14 (see FIG. 1) is exposed inside the tire, there is a concern about leakage of internal pressure and oxidative deterioration due to the filled air, but the exposed portion is the thickest rubber in a general tire. The leakage of internal pressure at the crown can be minimized by the thickness of the rubber. Further, the oxidative deterioration can be suppressed by filling the tire with nitrogen gas.

[effect]
As described above, the method for manufacturing the pneumatic tire 1 includes a bead member (bead core 11, bead filler 12), carcass layer 13, sidewall rubber 16, rim cushion rubber 17, and part of the inner liner 18. Side member molding step ST11 (see FIGS. 3 and 4) for molding side member X having side inner liner 181 to be configured, and a pair of side members X, X, belt layer 14 and tread rubber 15 on rigid core 24 And a green tire forming step ST12 (see FIG. 5) for forming the green tire Z (see FIG. 7) (see FIG. 2).

  Moreover, the manufacturing method of this pneumatic tire 1 shape | molds the side member X which has the side inner liner 181 which comprises a bead member (bead core 11, bead filler 12), the carcass layer 13, and a part of inner liner 18. As shown in FIG. Side member molding step ST21 (see FIGS. 14 and 15) and a pair of side members X and X, sidewall rubber 16, rim cushion rubber 17, belt layer 14 and tread rubber 15 are arranged on rigid core 24. A green tire forming step ST22 (see FIG. 5) for forming the green tire Z (see FIG. 7) (see FIG. 13).

  2 and 13, the side member X (see FIGS. 3 and 14) having at least the bead members 11 and 12 and the carcass layer 13 is assembled in advance, and the side member X is disposed on the rigid core 24. Thus, the green tire Z is formed (see FIG. 5). At this time, since the annular side member X can be disposed on the rigid core 24 from the side of the rigid core 24 (see FIG. 6), the carcass layer is not affected by the circumferential length difference between the bead portion and the tread portion. 13 (side member X) can be easily disposed on the rigid core 24. Thereby, there exists an advantage which can simplify the manufacturing process of a tire, and there exists an advantage which can improve the quality of a tire. In addition, since the green tire Z can be formed on the pre-assembled rigid core 24, for example, compared with a configuration (not shown) in which a rigid core is subsequently assembled inside the carcass layer and bead assembly. Thus, there is an advantage that the configuration of the rigid core can be simplified.

  In particular, in the configuration of FIGS. 2 and 13, for example, when manufacturing two types of pneumatic tires 1A and 1B having the same cross-sectional height SH and different tread widths TW1 and TW2 as shown in FIG. Be beneficial. 2 and 13, the pneumatic tire 1 includes left and right carcass layers 13 and 13 having a divided structure and left and right side inner liners 181 and 181 having a divided structure (see FIG. 1). ), The left and right side members X, X can be independently molded in a state of being separated from each other (see, for example, FIGS. 3 and 4). Then, the side member X can be shared in two types of pneumatic tires 1A and 1B (see FIG. 9) having the same cross-sectional height SH and different tread widths TW1 and TW2. This has the advantage that the inventory of semi-finished products can be reduced.

  Further, in the method for manufacturing the pneumatic tire 1, in the green tire molding step ST12 (ST22), the lower belt inner liner 182 constituting a part of the inner liner 18 and the left and right side inner liners 181 and 181 are mutually connected. The green tire Z is formed on the rigid core 24 while being wrapped (see FIGS. 5, 7 and 8). Thereby, the inner peripheral surface of the carcass layers 13 and 13 and the inner peripheral surface of the belt layer 14 are covered without a gap.

  Further, in the method for manufacturing the pneumatic tire 1, in the green tire molding step ST12 (ST22), the left and right side inner liners 181 and 181 are disposed on the rigid core 24 while being wrapped with each other, and the green tire Z is disposed. Molding is performed (see FIGS. 28 and 30). Thereby, the inner peripheral surface of the carcass layers 13 and 13 and the inner peripheral surface of the belt layer 14 are covered without a gap.

  Further, in the method for manufacturing the pneumatic tire 1, in the green tire molding step ST12 (ST22), the left and right side inner liners 181 and 181 are arranged on the rigid core 24 in a state where they are separated from each other. Z is formed (see FIG. 31).

  Further, the manufacturing method of the pneumatic tire 1 includes a side for forming a side member X (see FIG. 22) having a bead member (bead core 11, bead filler 12), a carcass layer 13, a sidewall rubber 16, and a rim cushion rubber 17. A member forming step ST31, and a green tire forming step ST32 for forming the green tire Z by arranging the inner liner 18, the pair of side members X and X, the belt layer 14 and the tread rubber 15 on the rigid core 24 (see FIG. 23). (See FIG. 21).

  The pneumatic tire 1 is manufactured by a side member molding step ST41 for molding a side member X (see FIG. 25) having a bead member (bead core 11, bead filler 12) and a carcass layer 13, an inner liner 18, A green tire molding step ST42 in which the pair of side members X and X, the sidewall rubber 16, the rim cushion rubber 17, the belt layer 14 and the tread rubber 15 are arranged on the rigid core 24 to mold the green tire Z (see FIG. 23). (See FIG. 24).

  21 and 24, the side member X (see FIGS. 22 and 25) having at least the bead members 11 and 12 and the carcass layer 13 is assembled in advance, and the side member X is disposed on the rigid core 24. Thus, a green tire Z (not shown) is formed. At this time, since the annular side member X can be disposed on the rigid core 24 from the side of the rigid core 24 (see FIG. 6), the carcass layer is not affected by the circumferential length difference between the bead portion and the tread portion. 13 (side member X) can be easily disposed on the rigid core 24. Thereby, there exists an advantage which can simplify the manufacturing process of a tire, and there exists an advantage which can improve the quality of a tire. In addition, since the green tire Z can be formed on the pre-assembled rigid core 24, for example, compared with a configuration (not shown) in which a rigid core is subsequently assembled inside the carcass layer and bead assembly. Thus, there is an advantage that the configuration of the rigid core can be simplified.

  FIG. 32 is a chart showing the results of performance tests of the pneumatic tire manufacturing method according to the embodiment of the present invention.

  In this performance test, (1) water pressure resistance and (2) internal pressure retention performance were evaluated for a plurality of pneumatic tires with different manufacturing methods (see FIG. 32).

  (1) Evaluation regarding pressure resistance performance was made by assembling a test tire with a rim, injecting water into the tire, measuring the pressure when the tire broke down, and indexing the conventional example as 100. The larger the index, the better the pressure resistance performance, which is preferable.

  (2) For the evaluation of the internal pressure retention performance, the tire is left for 3 months under an initial pressure of 200 [kPa], a room temperature of 21 [° C.] and no load. The measurement interval of the internal pressure is every 4 days, and the a value is obtained by regressing the following expression Pt / Po = exp (−at) as the measurement pressure Pt, the initial pressure Po, and the elapsed days t. Using the obtained a, t = 30 (days) is substituted, and β = [1-exp (−at)] × 100 is obtained. Let β be the rate of pressure drop per month (% / month). The reciprocal was expressed as an index with the conventional example being 100. The larger the index, the better the internal pressure holding performance, which is preferable.

  The pneumatic tire 1 of Examples 1 and 2 has the structure described in FIGS. 1 and 26, and the inner liner 18 includes a pair of side inner liners 181 and 181 and an under belt inner liner 182. The pneumatic tires 1 of Examples 1 and 2 are both manufactured by the manufacturing method described in FIGS. The pneumatic tires 1 of Examples 3 and 4 have the structure shown in FIG. 28, and the inner liner 18 wraps the left and right side inner liners 181 and 181 with each other. The pneumatic tire 1 of Examples 3 and 4 is based on the manufacturing method described in FIGS. 2 to 6, and the side inner liner extended to the center region of the tread portion in the side member forming step ST <b> 11 (see FIG. 4). 181 is used, and in the green tire molding step ST12 (see FIG. 5), the lower belt inner liner 182 is omitted, and the left and right side inner liners 181 and 181 are overlapped with each other (see FIG. 28). Tire Z (not shown) is molded.

  Further, in Example 2, the side inner liners 181 and 181 of the left and right side members X and X and the belt lower inner liner 182 of the belt and tread assembly Y are brought into contact with each other with the end surfaces of the edge portions being brought into contact with each other. They are arranged in a state (not shown). For this reason, the lap width W1 is W1 = 0 [mm], but the butted portion is not opened all around the tire (W1 is not negative). Similarly, in the fourth embodiment, the left and right side inner liners 181 and 181 are arranged in a state where the end surfaces of the edge portions are brought into contact with each other (not shown). For this reason, the lap width W4 is W4 = 0 [mm], but the butted portion is not opened all around the tire (W4 is not negative).

  Moreover, the pneumatic tire 1 of Examples 1-4 has tire size 235 / 40R18. The inner liner 18 (side inner liners 181 and 181 and under-belt inner liner 182) is made of a butyl rubber composition having a thickness of 1.0 [mm].

  In the conventional pneumatic tire, the inner liner 18 has a structure in which the pair of side inner liners 181 and 181 and the belt inner liner 182 have a single structure (one rubber sheet) in the configuration of FIG. (Omitted). This conventional pneumatic tire is manufactured by an existing manufacturing method.

  As shown in the test results, in the pneumatic tires 1 of Examples 1 to 4, it can be seen that (1) water pressure resistance and (2) internal pressure retention performance are appropriately secured.

  1, 1A, 1B Pneumatic tire, 11 bead core, 12 bead filler, 13 carcass layer, 131, 132 carcass ply, 133 intermediate carcass ply, 14 belt layer, 141, 142 cross belt, 143 belt cover, 144 edge cover, 15 Tread rubber, 16 side wall rubber, 17 rim cushion rubber, 18 inner liner, 181 side inner liner, 182 under belt inner liner, 19 chafer, 21 side member molding drum, 22 member presser, 23 turn-up bladder, 18 in rigid body Child, 25, 26 Gripping device, 27 Wrapped bladder, 28, 29 Roller, 30 bladder, X side member, Z green tire

Claims (7)

A pneumatic tire manufacturing method comprising a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner,
A side member molding step of molding a side member having a side inner liner constituting a part of the bead member, the carcass layer, the sidewall rubber, the rim cushion rubber, and the inner liner;
A pneumatic tire manufacturing method comprising: a green tire molding step of molding a green tire by arranging a pair of the side members, the belt layer, and the tread rubber on a rigid core. A pneumatic tire manufacturing method comprising a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner,
A side member molding step of molding a side member having a side inner liner constituting a part of the bead member, the carcass layer, and the inner liner;
And a green tire molding step of molding a green tire by arranging a pair of the side members, the sidewall rubber, the rim cushion rubber, the belt layer, and the tread rubber on a rigid core. A method for manufacturing a tire.   In the green tire molding step, the green tire is molded by placing the lower belt inner liner constituting a part of the inner liner and the left and right side inner liners on the rigid core while wrapping each other. The manufacturing method of the pneumatic tire of Claim 1 or 2.   The method for manufacturing a pneumatic tire according to claim 1 or 2, wherein, in the green tire molding step, the green tire is molded by arranging the left and right side inner liners on the rigid core while lapping each other.   The pneumatic tire manufacturing method according to claim 1 or 2, wherein in the green tire molding step, the left and right side inner liners are arranged on the rigid core in a state of being separated from each other, and the green tire is molded. Method. A pneumatic tire manufacturing method comprising a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner,
A side member molding step of molding a side member having the bead member, the carcass layer, the sidewall rubber, and the rim cushion rubber;
A pneumatic tire manufacturing method comprising: a green tire forming step of forming a green tire by disposing the inner liner, the pair of side members, the belt layer, and the tread rubber on a rigid core. A pneumatic tire manufacturing method comprising a pair of bead members, a pair of carcass layers, a belt layer, a tread rubber, a pair of sidewall rubbers, a pair of rim cushion rubbers, and an inner liner,
A side member molding step of molding a side member having the bead member and the carcass layer;
A green tire molding step of molding a green tire by arranging the inner liner, the pair of side members, the sidewall rubber, the rim cushion rubber, the belt layer, and the tread rubber on a rigid core. A method for producing a pneumatic tire.