CN101137495B - Manufacturing method of run-flat tire - Google Patents

Abstract

The present invention provides a method for manufacturing a run-flat tire, which is less prone to eccentricity than conventional methods, and thus can manufacture run-flat tires with good uniformity by means of simple equipment and processes. The manufacturing method includes the following steps: respectively arrange an inner liner rubber (19), a carcass layer (14) and a reinforcing rubber member (18) for reinforcing the sidewall parts on both sides at predetermined positions on the outer periphery of the building drum; For the first bead (1a) and the filler strip (12), deform the inner part of the first bead (1a) into a ring shape; roll up the end (14b) of the above-mentioned carcass layer (14) and Paste it; paste the rubber members (13a, 13b) constituting the ring-shaped bulging part on the side of the above-mentioned filler strip (12) of the ring-shaped molding; The cord (BW) is adhered in a spiral shape to form a second bead (1b).

Description

Method for manufacturing run-flat tires

technical field

The present invention relates to a side-reinforced run-flat tire in which a second bead is disposed on an annular bulging portion bulging outward in the tire width direction of the bead portion, and a method for manufacturing the same. the

Background technique

A run-flat tire is a tire that can safely travel a certain distance even if the air pressure inside the tire drops due to a failure such as a flat. As one of the tire structures for enabling such a run-flat run, there is known a run-flat tire having a reinforcing rubber layer on a sidewall portion. With such a run-flat tire, when the air pressure inside the tire decreases, the reinforcing rubber layer supports the tire and prevents the tire from completely flattening, thereby allowing run-flat running. the

However, in a state where the air pressure inside the tire is lowered, there is a problem that the bead portion tends to come off from the rim because the bead portion is less pressed against the rim, thereby reducing its fitting force with the rim. For this reason, a so-called double bead type run-flat tire has been proposed, that is, in addition to arranging beads on the outer peripheral side of the bead portion of the rim, the bead portion also bulges outward in the tire width direction. A bead is disposed on the annular bulge (see Patent Documents 1 and 2 below). With this structure, the ring-shaped bulge, which has high elasticity due to the bead, can hold the rim flange during run-flat running, thereby preventing beading. the

Fig. 16 is a tire meridian sectional view showing a conventional double bead type run-flat tire. The bead 1 a and the bead filler 12 are provided in the bead portion 1 , and the ply 14 is rolled up from the inside to the outside to sandwich the bead 1 a and the bead filler 12 . The sidewall portion 2 has a sidewall rubber 11 disposed on its outer side, and a reinforcing rubber layer 9 having a substantially crescent-shaped cross-section is disposed on its inner side. The annular bulging portion 10 is formed so as to bulge outward in the tire width direction of the bead portion 1, and has an annular second bead 1b. In addition, the reinforcing layer 16 is arranged along the inner peripheral surface of the annular bulge 10 , and the rim strip 17 is arranged at a portion directly in contact with the rim 8 . the

Such a run-flat tire has a problem that, when the side reinforcement is bent to generate tension in the carcass layer during run-flat running, the bead is likely to lift up and the bead is likely to fall off. When increasing the fastening force of the bead or reducing the amount of tire deflection in order to avoid this problem, excessive reinforcement is required, which leads to problems such as difficulty in rim assembly and increase in weight. the

In addition, Patent Document 3 below describes a tire in which, in a side-reinforced run-flat tire having no second bead 1b, the reinforcing layer 16 is formed by winding one or a plurality of cords. Scroll-like (spiral-like) configuration. However, since there is no description of its manufacturing method, it can be understood that this type of tire is manufactured by pasting sheets in the same way as ordinary reinforcing layers. the

On the other hand, the run-flat tire shown in FIG. 16 was manufactured through the following manufacturing steps. That is, as shown in (a) to (c) of FIG. And the reinforcing rubber member 18 that becomes the reinforcing rubber layer 9 . Then, the carcass 14 is disposed on the outer peripheral side thereof, and the bead 1a and the bead filler 12 are inserted from the outside at predetermined positions. Next, the carcass 14 is rolled up, and the carcass 14 is arranged so as to sandwich the bead 1 a and the bead filler 12 . Next, the bead 1a, the bead filler 12, and the carcass 14 are vertically approached by a method such as slightly expanding the surface to be formed 20 of the forming drum. On the outer peripheral side of the carcass layer 14, in addition to the rubber member 22 constituting the annular bulge 10 and the second bead 1b, a reinforcing layer, a rim strip, a side rubber, and the like are arranged. As the second bead 1b, a bead wire assembly produced by helically winding a bead wire is used. Thereafter, the molded product is deformed along the shape of the tire to form the tread portion 3, and the process proceeds to a vulcanization step. the

However, in the above-mentioned manufacturing method, when arranging the annular second bead 1b, a mechanism for affixing it without eccentricity with respect to the tire axis is required. In addition, when the assembly of bead wires is manufactured in advance, there is also a problem that the support mechanism for winding and the device for bundling the assembly are relatively large. In addition, there is a problem that since the second bead 1b is arranged before expanding and deforming the molded product into a tire shape, eccentricity and cross-sectional shape of the second bead 1b are likely to occur when the molded product is expanded and deformed. Deformation etc. the

In addition, as described in Patent Document 3, when a reinforcing layer having a cord-shaped spiral winding structure is pasted on a molded product to manufacture, similar to the above-mentioned case of pasting the second bead 1b, the Uniformity problems, equipment and process problems caused by eccentricity. the

On the other hand, for ordinary pneumatic tires other than run-flat tires, there is known a tire manufacturing method in which a bead (corresponding to a first bead) is formed by helically winding a bead wire on a molded product (for example, refer to Patent Document 4~5). However, these manufacturing methods employ a method in which an annular core having the same shape as the inner surface of the tire is used, and constituent members are sequentially arranged (pasted) on the annular core, and in the case of a run-flat tire, there is no Take this approach. Therefore, a method of forming a bead by helically winding a bead wire on a molded article has not been known so far in a method of manufacturing a run-flat tire. the

Patent Document 1: Japanese Patent Application Laid-Open No. 51-116507

Patent Document 2: Japanese Patent Application Laid-Open No. 53-138106

Patent Document 3: Japanese Patent Laid-Open No. 2001-80318

Patent Document 4: Japanese Special Publication No. 2004-501815

Patent Document 5: Japanese Special Publication No. 2003-514706

Contents of the invention

Therefore, it is an object of the present invention to provide a method for manufacturing a run-flat tire that can produce a run-flat tire with good uniformity by using simple equipment and processes because it is less likely to cause eccentricity of the second bead 1b than conventional methods. Run-flat tires. the

In addition, another object of the present invention is to provide a run-flat tire and a method of manufacturing the same: since the eccentricity of the reinforcing layer and the like is less likely to occur than conventional methods, it can be manufactured with simple equipment and processes run-flat tires. the

The above objects can be achieved by the present invention as described below. the

That is, the method for manufacturing a run-flat tire according to the present invention is characterized in that it includes the steps of arranging an inner liner rubber, a reinforcing rubber member for reinforcing sidewall portions on both sides, respectively, at predetermined positions on the outer periphery of a building drum, and ply; a pair of first beads and filler strips are arranged, and the position inside the first bead is deformed into a toroid; before or after the deformation, the above-mentioned ply is rolled up Paste the end part; paste the rubber member constituting the ring-shaped bulging part on the side of the above-mentioned filling rubber strip of the ring-shaped molded product; stick the cord in a spiral shape while rotating the pasted molded product around the axis A second bead is formed on the above-mentioned rubber member; and the above-mentioned annular molded product is formed by arranging inner liner rubber and reinforcing rubber members for reinforcing sidewall portions on both sides at predetermined positions on the outer periphery of the building drum, and A carcass layer in which the cords are arranged in the width direction is respectively arranged on the outer side of each reinforcing rubber member than the vicinity of the outer side end in the drum width direction; A pair of first beads and a filler strip; deforming the obtained molded product into a ring shape at a position inner than the first bead; placing the outer end of each of the above-mentioned carcass layers toward the outer periphery of the deformed molded product Roll up the sides and tape it on that perimeter side. the

According to the method of manufacturing a run-flat tire of the present invention, since the cord is attached to the above-mentioned rubber member in a spiral shape while rotating the ring-shaped molding around the axis, it is not necessary to arrange a ring-shaped The eccentricity preventing mechanism of the conventional device for the second bead. In addition, compared with conventional methods, eccentricity is less likely to occur when pasting, and eccentricity and cross-sectional deformation are less likely to occur when expanding and deforming molded objects, and the uniformity is good. In addition, it is not necessary to manufacture bead wire aggregates in advance, but can be manufactured only by adding a cord bonding device, so that tires can be manufactured with simple equipment and processes. the

According to this manufacturing method, after the carcass is arranged on the outer side of the reinforcing rubber member, a pair of first beads and a filler strip are arranged on the outer side of the carcass slightly outside the inner end, and then the first bead Since the inner portion is deformed into a ring shape, the inner turn-up portion of the carcass can be easily arranged inside the bead. In addition, since the outer end of the carcass is rolled up toward the outer peripheral side of the molded product thus obtained and stuck, the carcass is easily pressed onto the shaped reinforcing rubber member. As a result, a run-flat tire excellent in bead-off resistance can be manufactured with good productivity without increasing the weight. In addition, since one end of the carcass is rolled from the outside to the inside of the first bead, during run-flat running, if the sidewall reinforcement is bent and tension is generated in the carcass, tension will be generated around the bead. The tire toe is pressed against the rim seat by the torque, so it is difficult to produce bead off. the

In addition, the above-mentioned cord is a cord coated with unvulcanized rubber, and after the cord is attached to the same surface in a spiral shape, it is preferable to repeatedly attach the cord to the previous cord in a spiral shape. process on the upper surface of the layer. When cords covered with unvulcanized rubber are used, bonding between the cords becomes easy, and by repeating the above steps, a second bead composed of multiple layers can be formed. the

On the other hand, another run-flat tire manufacturing method according to the present invention is characterized in that it includes the steps of arranging inner liner rubber at predetermined positions on the outer periphery of the building drum, and reinforcing the sidewall portions on both sides. A rubber member, and a carcass; a pair of first beads and a filler strip are arranged, and the position inside the first bead is deformed into a ring shape; before or after the deformation, the above-mentioned carcass is rolled up and pasted The end portion of the ring-shaped molding is pasted on the side of the above-mentioned filling strip; the rubber member that constitutes the annular bulge is pasted; while the pasted molding is rotated around the axis, the cord is pasted in a spiral shape on the above-mentioned The reinforcement layer is formed on the area of the rubber member facing the rim flange; the above-mentioned ring-shaped molding is formed by the following process: the inner liner rubber is arranged at a predetermined position on the outer periphery of the forming drum and the sidewall parts on both sides are reinforced. Reinforcing rubber members, and each reinforcing rubber member is provided with a ply in which the cords are arranged in the width direction at a position more outside than the vicinity of the outside end in the drum width direction of each reinforcement rubber member; A pair of first beads and filler strips are arranged on the outer side; the part of the obtained molded product inner than the first bead is deformed into a ring shape; the outer end of each of the above-mentioned plies is deformed The outer peripheral side of the molded product is rolled up and pasted on the outer peripheral side. the

According to another method of manufacturing a run-flat tire according to the present invention, since the cord is helically attached to the region of the rubber member facing the rim flange while rotating the annular molding around the axis, Therefore, there is no need for an eccentricity prevention mechanism like the conventional device in which the annular reinforcing layer sheets are disposed. In addition, compared with conventional methods, eccentricity is less likely to occur when pasting, and eccentricity and cross-sectional deformation are less likely to occur when expanding and deforming molded objects, and the uniformity is good. In addition, it is not necessary to pre-fabricate a reinforcing layer sheet in which cords are wound in a spiral shape, and it can be manufactured only by adding a cord pasting device, so tires can be manufactured with simple equipment and processes. the

In the above-mentioned technical solution, it is preferable to form the above-mentioned reinforcing layer by affixing the above-mentioned cords in a spiral form from the inner peripheral side to the outer peripheral side of the tire. A process in which cords extending continuously from layer to layer are adhered to the above-mentioned rubber member in a spiral shape to form a second bead. the

According to this manufacturing method, since the cord is attached to the above-mentioned rubber member in a spiral shape while rotating the annular molded product around the axis, eccentricity unlike the conventional device in which the annular second bead is arranged is unnecessary. prevent agency. In addition, compared with conventional methods, eccentricity is less likely to occur when pasting, and eccentricity and cross-sectional deformation are less likely to occur when expanding and deforming molded objects, and the uniformity is good. In addition, it is not necessary to manufacture the aggregate of bead wires in advance, but can be manufactured by using a cord bonding device for the reinforcing layer, so that the tire can be manufactured with simple equipment and processes. the

In addition, the above-mentioned cord is a cord coated with unvulcanized rubber, and after the above-mentioned cord is adhered to the same surface in a spiral shape in the step of forming the above-mentioned second bead, it is preferable to repeatedly carry out the process of forming the cord. The process of sticking on the upper surface of the previous cord layer in a spiral shape. When cords covered with unvulcanized rubber are used, bonding between the cords becomes easy, and by repeating the above steps, a second bead composed of multiple layers can be formed. the

According to this manufacturing method, after the carcass is arranged on the outer side of the reinforcing rubber member, a pair of first beads and a filler strip are arranged on the outer side of the carcass slightly outside the inner end, and then the first bead Since the inner portion is deformed into a ring shape, the inner turned-up portion of the carcass can be easily arranged inside the bead. In addition, since the outer end of the carcass is rolled up on the outer peripheral side of the molded product obtained in this way and stuck to the outer peripheral side, the carcass is easily attached to the shaped reinforcing rubber member. As a result, a run-flat tire excellent in bead-off resistance can be manufactured with good productivity without increasing the weight. In addition, since one end of the carcass is rolled from the outside to the inside of the first bead, during run-flat running, if the sidewall reinforcement is bent and tension is generated in the carcass, tension will be generated around the bead. The bead toe is pressed against the bead seat of the rim due to the torque, so it is difficult to cause the bead to fall off. the

On the other hand, the run-flat tire of the present invention is a run-flat tire produced by any one of the methods described above, and has a pair of bead portions, sidewall portions, a tread portion, a belt layer, a carcass layer, A reinforcing rubber layer and an annular bulging portion, the bead portion has an annular first bead and a filler strip disposed on the tire outer peripheral side of the first bead, and the sidewall portions extend from the bead portion to Extending outward in the tire radial direction, the tread portion is provided between the sidewall portions, the belt layer is provided on the tire inner peripheral side of the tread portion, and the carcass layer is composed of a carcass ply rolled up at the first bead. The above-mentioned reinforcing rubber layer is arranged on the above-mentioned sidewall part, and the above-mentioned annular bulging part bulges outward from the above-mentioned bead part in the tire width direction, and has a second bead, and the above-mentioned annular bulging part is characterized in that A reinforcing layer in which cords are arranged helically is provided in a region facing the rim flange, and the cords continuously extending from the reinforcing layer are wound helically to form the second bead. the

According to the run-flat tire of the present invention, since the cords forming the reinforcing layer and the second bead are continuous and wound in a helical shape, the reinforcing layer and the second bead can be formed by the same cord attaching device, thereby enabling Manufacture tires with simple equipment and processes. In addition, since the reinforcing layer and the second bead are less likely to be eccentric, a run-flat tire with good uniformity can be obtained. the

Description of drawings

Fig. 1 is a tire meridian sectional view showing an example of a run-flat tire obtained by the first invention. the

Fig. 2 is a sectional view of main parts schematically showing an example of a bead portion of a run-flat tire obtained by the first invention. the

Fig. 3 is a process diagram showing an example of a method of manufacturing a run-flat tire according to the first invention. the

Fig. 4 is a process diagram showing an example of a method of manufacturing a run-flat tire according to the first invention. the

Fig. 5 is a process diagram showing an example of a method of manufacturing a run-flat tire according to the first invention. the

Fig. 6 is a tire meridian sectional view showing another example of the run-flat tire obtained by the first invention. the

Fig. 7 is a process diagram showing another example of the manufacturing method of the first invention. the

Fig. 8 is a main part diagram showing another example of the run-flat tire obtained by the first invention. the

Fig. 9 is a tire meridian sectional view showing an example of a run-flat tire obtained by the second invention. the

Fig. 10 is a sectional view of main parts schematically showing an example of a bead portion of a run-flat tire obtained by the second invention. the

Fig. 11 is a process diagram showing an example of a method of manufacturing a run-flat tire according to the second invention. the

Fig. 12 is a process diagram showing an example of a method of manufacturing a run-flat tire according to the second invention. the

Fig. 13 is a process diagram showing an example of a method of manufacturing a run-flat tire according to the second invention. the

Fig. 14 is a tire meridian sectional view showing another example of a run-flat tire obtained by the second invention. the

Fig. 15 is a process diagram showing another example of the manufacturing method of the second invention. the

Fig. 16 is a tire meridian sectional view showing an example of a conventional run-flat tire. the

Fig. 17 is a process diagram illustrating a conventional run-flat tire manufacturing method. the

Explanation of reference signs

1 bead part

1a 1st bead

1b 2nd bead

9 reinforced rubber layer

10 Annular bulging part

11 sidewall rubber

12 filler strips

13 ring rubber body

13a Rubber components

13b rubber components

14 ply

14a One end (inside)

14b The other end (outside)

16 reinforcement layer

18 Reinforcing rubber member for reinforcing the sidewall

19 inner liner rubber

20 forming drums

C tire equator line

BW cord

SC cord

Detailed ways

Embodiment of the first invention

Next, an embodiment of the first invention will be described with reference to the drawings. Fig. 1 is a tire meridian cross-sectional view showing an example of a run-flat tire obtained by the manufacturing method of the first invention, and Fig. 2 is a main part cross-sectional view schematically showing a bead portion thereof. 3 to 5 are process diagrams of an example of the production method of the first invention. the

The method for manufacturing a run-flat tire according to the first invention includes the following steps: arranging an inner liner rubber, a carcass layer, and reinforcing rubber members for reinforcing sidewall portions on both sides at predetermined positions on the outer periphery of a building drum; arranging 1 For the first bead and the filler strip, the inner side of the first bead is deformed into a ring shape; before or after the deformation, the end portion of the above-mentioned carcass is rolled up and pasted. Thus, a ring-shaped molded product was obtained. The first invention further includes the steps of: adhering a rubber member constituting an annular bulging portion to the side of the above-mentioned rubber filler of the annular molded product; The second bead is formed by sticking it spirally on the above-mentioned rubber member. the

As shown in FIGS. 3 to 5 , this embodiment shows an example in which the above-mentioned annular molded product is formed through the following steps: the inner liner rubber 19 and the rubber for reinforcing the sidewalls on both sides are respectively arranged at predetermined positions on the outer periphery of the forming drum 20 ; The reinforcing rubber members 18 of the upper portion, and the carcass layers 14 in which the cords are arranged in the width direction are arranged at positions more outside than the vicinity of the outer ends in the drum width direction of each reinforcing rubber members 18; A pair of first bead 1a and filler strip 12 are arranged at a position slightly outside the inner end in the width direction; the part of the obtained molded product inner than the first bead 1a is deformed into a ring shape; each of the above-mentioned cords The outer end 14b of the layer 14 is rolled up toward the outer peripheral side of the deformed molded article and stuck to the outer peripheral side of the deformed molded article. the

First, the run-flat tire obtained by this embodiment will be described. the

The run-flat tire of the present embodiment

As shown in FIGS. 1 to 2 , the run-flat tire of this embodiment has a pair of bead portions 1 , a sidewall portion 2 and a tread portion 3 . Extending outward, the tread portion 3 is provided between the sidewall portions 2 . In the bead portion 1, a bead 1a (corresponding to the above-mentioned first bead) formed by forming a bead wire bundle into a ring in the tire circumferential direction is arranged, and a cross-sectional bead is arranged on the tire outer periphery of the bead 1a. A triangular filler strip 12 extending radially of the tire. In addition, a rim strip 17 having excellent wear resistance is disposed at a portion directly in contact with the rim 8 . the

The carcass layer 4 is composed of a carcass layer 14 in which cords are arranged at an angle of approximately 90° to the tire equator line C, and is respectively provided with respect to the pair of bead portions 1 . One end 14 a of the carcass layer 14 is rolled up from the outside to the inside of the first bead 1 a , and the other end 14 b is arranged inside the belt layer 6 . the

In the first invention, it is preferable to arrange the other end 14b of the carcass layer 14 in the range of 60 to 90% of the width of both outer sides of the widest layer (usually the innermost layer) in the belt layer 6 . As a result, the tire reinforcing effect by cooperation of the carcass layer 14 and the belt layer 6 can be maintained, and the weight of the tire can be reduced, and the rolling resistance and ride comfort can be improved. the

On the inner peripheral side of the carcass layer 4, an inner liner 5 for maintaining air pressure is arranged, and on the tire inner peripheral side of the tread portion 3, a belt layer 6 for reinforcement by a hoop effect and, if necessary, a reinforcement are arranged. belt layer7. The belt layer 6 is composed of sub-belt layers in which cords are arranged in parallel at a predetermined angle with respect to the tire equator line C. As shown in FIG. the

A steel wire or the like can be used as the bead wire, and steel or organic fibers such as polyester, rayon, nylon, and aramid can be used as the cords constituting the carcass layer 4 and the belt layer 6 . In order to improve the adhesion of all these cords to rubber, they are usually subjected to surface treatment or bonding treatment, etc. the

A sidewall rubber 11 is arranged on the outer side of the sidewall portion 2 , and a reinforcing rubber layer 9 having a substantially crescent-shaped cross section is arranged on the inner side of the sidewall portion 2 . As a result, when the air pressure inside the tire decreases, the bending deformation of the tire can be suppressed, and run-flat running can be performed. The reinforcing rubber layer 9 is formed of, for example, a rubber layer having a rubber hardness (rubber hardness measured in accordance with JIS K6253 Type A Durometer hardness test, the same below) of 65° to 90°. In addition, the reinforcing rubber layer 9 included in the run-flat tire of the first invention can be applied as long as it is a reinforcing rubber layer used in conventional side-reinforced run-flat tires, and the hardness and thickness are not particularly limited. . The reinforcing rubber layer 9 is not limited to a structure composed of a single rubber layer, and may have a structure composed of a plurality of rubber layers having different physical properties such as hardness. the

As shown in FIG. 2 , in this embodiment, there is also an annular bulging portion 10 that bulges outward in the tire width direction from at least one bead portion 1 and has a second bead 1b. . The annular bulging portion 10 bulges outward in the tire width direction from the rim flange 8a, and has an inner peripheral surface extending along the outer peripheral side curved surface of the rim flange 8a. As a result, the annular bulging portion 10 can effectively embrace the rim flange 8a, thereby preventing bead slipping. The annular bulging portion 10 is preferably formed on each of the bead portions 1 on both sides. the

A bead 1b (corresponding to the above-mentioned second bead) in which a bead wire forms a ring in the tire circumferential direction is arranged in the annular bulging portion 10 . The bead 1b according to the present embodiment is arranged so that when mounted on a rim, its center position is located closer to the tire outer peripheral side and outside in the tire width direction than the outermost radial point of the rim flange 8a. In addition, in the first invention, the arrangement position of the bead 1b is not particularly limited. the

The reinforcement layer 16 is disposed substantially along the inner peripheral surface of the annular bulging portion 10 , thereby reinforcing the inner peripheral surface of the annular bulging portion 10 and suppressing abrasion. As the reinforcing layer 16, a chafer made of organic fibers such as steel cords, rayon, nylon, polyester, and aramid can be exemplified. the

As shown in FIG. 2 , the carcass layer 14 is rolled up from the outside to the inside at the bead portion 1 a , and one end 14 a thereof is disposed near the bottom of the bead filler 12 . The height H of the bead filler 12 can vary, for example, within the range of 15 to 65 mm. However, from the viewpoint of tire durability and weight reduction, it is preferable to place the end 14a of the carcass 14 on the basis of the tire outer peripheral end of the bead portion 1a. The height P is made into the range of 10-20 mm. the

In addition, the cross-sectional shapes of the annular bulging portion 10, the annular rubber body 13, and the filler strip 12 of the run-flat tire obtained by the first invention are not limited to those shown in this embodiment. the

Method for manufacturing run-flat tires

Next, a method of manufacturing the run-flat tire of the present embodiment will be described with reference to FIGS. 3 to 5 . the

First, a cylindrical forming drum 20 is prepared. The forming drum 20 is a member having a conventionally known diameter-reducing and diameter-expanding mechanism, and its central part has an air bag for shaping or a diameter-expanding mechanism having the same function. In addition, an airbag mechanism for rolling up the outer end of the carcass layer is provided as needed. the

Next, as shown in FIG. 3( a ), a process of arranging the inner liner rubber 19 , the reinforcing rubber members 18 for reinforcing the sidewall portions on both sides, and the carcass 14 at predetermined positions on the outer periphery of the forming drum 20 is carried out. Specifically, the center of the inner liner rubber 19 is arranged at the center of the outer periphery of the forming drum 20 , and the reinforcing rubber members 18 are arranged on both sides at intervals of the tread width from the center. In addition, the carcass layers 14 are respectively arranged on the outer sides from the vicinity of the outer ends in the drum width direction of the respective reinforcing rubber members 18 . At this time, the cords constituting the carcass layer 14 are aligned in the drum width direction. the

In this embodiment, an example in which the rim strip 17 and the reinforcement layer 16 are arranged on the outer side in the width direction of the inner liner rubber 19 is shown. The rim strip 17 is preferably arranged such that its end face is in contact with the inner liner rubber 19 or its end is overlapped with the inner liner rubber 19 . the

Next, as shown in FIG. 3( b ), a step of arranging the pair of first beads 1 a and the bead filler 12 slightly outside the inner end in the drum width direction of the carcass 14 is carried out. The first bead 1a and the bead filler 12 may be arranged sequentially from the outside through the jacket, but they are preferably arranged in a structure in which they are integrated. the

Next, as shown in FIG. 3( c ), a step of deforming a portion of the obtained molded product inside the first bead 1 a into a ring shape is carried out. This deformation can be performed by forming drums 20 . At this time, a bead locking mechanism may be provided in advance on the forming drum 20, and the bead portion 1a may be clamped from the inner peripheral side of the tire by the rim strip 17, the ply 14, and the like. Thus, deformation can be performed with high precision. Due to this deformation, the one end 14a of the carcass 14 is sandwiched between the inner liner rubber 19 and the first bead 1a. 3( c ) shows an example in which the both sides of the enlarged diameter portion of the forming drum 20 are substantially planar, but it is preferable that the both sides of the enlarged diameter portion be formed as curved surfaces that protrude outward like the shape of the inner surface of the tire. the

Next, as shown in FIG. 4( a ), a step of rolling the outer end (the other end 14 b ) of each carcass layer 14 toward the outer peripheral side of the deformed molded product and affixing it to the outer peripheral side is carried out. Through this process, a ring-shaped molded product is formed. the

At this time, the carcass layers 14 may be individually or collectively rolled up by hand in a state in which the beads 1a are fixed using the bead locking mechanism, as required. In addition, the ply 14 can be easily rolled up by providing a rubber bladder called an air bladder to apply internal pressure. At this time, in order to roll up the reinforcing layer 16 and the rim strip 17 at the same time, a spacer may be interposed between them and the carcass 14 in advance, and the next step may be performed after peeling off the reinforcing layer 16 and the like. the

As shown in FIG. 4( b ), the first invention includes the step of sticking the rubber member 13 constituting the annular bulging portion to the side of the rubber filler 12 of the annular molding. The annular rubber body 13 is composed of the same type or two or more types of rubber members 13a, 13b, and the like. The annular rubber body 13 preferably has a rubber hardness of 40-75°, for example, and has sufficient rigidity and crack resistance to withstand repeated impacts transmitted from the rim 8 . The annular rubber body 13 is attached to the outer side of the bead filler 12 in the tire width direction with the ply 14 interposed between the annular rubber body 13 and the filler rod 12. the

As shown in FIG. 4(c), the first invention includes the step of forming the second bead 1b by affixing the cord BW to the rubber member 13 in a spiral shape while rotating the affixed molded product around its axis. Figures 5(a)-(b) show this process in more detail. In the illustrated example, the cord BW is first attached in a spiral form from the inner peripheral side to the outer peripheral side as indicated by the arrow, but it may be attached in the opposite direction. the

One cord BW or a plurality of cords BW may be pasted simultaneously, but one cord BW is preferably pasted in view of uniformity, strength, productivity, and the like. As the material of the cord BW, steel wires, steel cords, organic fibers such as polyester, rayon, nylon, and aramid can be used. That is, in the conventional method, since the annular bead is manufactured in advance, it is difficult to maintain the annular shape using organic fibers, but in the first invention, the uniformity is good even if the organic fibers are used because they are pasted. the

In addition, it is preferable to use a cord coated with an unvulcanized rubber from the viewpoint of facilitating bonding between the cords. Such unvulcanized rubber can be used, for example, when manufacturing the first bead, and rubber with a rubber viscosity of 50 to 80 can be used, for example. Here, the rubber viscosity is a value measured in accordance with the "Mooney viscosity test" in the "Physical testing methods for unvulcanized rubber" of JIS K6300. the

In the first invention, it is only necessary to paste the cord BW in a helical shape, and it is also possible to arbitrarily wrap the cord BW (here also includes a helical winding), but as shown in FIG. The BW is adhered to the same surface in a spiral form, and the step of affixing the cord BW to the upper surface in a spiral form is preferably repeated subsequently. the

In the present embodiment, an example in which five turns of the cord BW are attached in a spiral shape on the first surface, four turns on the next surface, and then three turns and two turns is shown. By gradually reducing the number of loop turns in this way, it is easy to maintain the shape of the second bead 1b after the vulcanization step. In addition, by affixing two or more turns to the uppermost layer, it is also easy to maintain the shape of the second bead 1b after the vulcanization step. In addition, the cord BW can be pasted along the recess formed by the two cords by pasting the cord BW on the same surface in a spiral shape, returning it, and pasting it on the upper surface in a spiral shape. into a spiral. the

Next, as shown in FIG. 4( c ), the reinforcing layer 16 and the rim strip 17 are rolled up and attached to predetermined positions. Further, the sidewall rubber 11 is arranged along the outer peripheral surface of the annular rubber body 13 from the annular bulging portion 10 toward the sidewall portion 2 . Thereafter, the belt layer 6 and the reinforcing belt layer 7 are formed on the tire outer peripheral side of the molded body, and tread rubber is arranged on the outer peripheral side to form the tread portion 3 . After introducing the green tire obtained as described above into a metal mold, it is vulcanized and molded. the

Other embodiments of the first invention

(1) In the above-mentioned embodiment, two plies are used, and the outer end of each of the above-mentioned plies is rolled up and pasted, and the other end of the ply is rolled up from the outside to the inside. As an example of molded products, a run-flat tire having the same carcass structure as the conventional one shown in FIG. 6 can be manufactured using one carcass ply. Even in this case, the step of forming the second bead 1b by affixing the cord BW to the rubber member 13 in a helical shape while rotating the molded product around its axis may be performed similarly to the above-mentioned embodiment. the

That is, as shown in FIGS. 7( a ) to ( c ), the first invention may include the steps of disposing inner liner rubber 19 at predetermined positions on the outer periphery of the building drum 20, and rubber for reinforcing the sidewall portions on both sides. Reinforcing rubber member 18 and carcass layer 14; disposing a pair of first bead 1a and filler strip 12, deforming the inner part of the first bead 1a into a ring shape; before or after the deformation, rolling and The ends of the above-mentioned carcass 14 are pasted. the

Specifically, a cylindrical forming drum 20 as described above is prepared, and as shown in FIG. The rubber member 18 , and the carcass 14 . At this time, the center of the inner liner rubber 19 is arranged at the center of the outer periphery of the forming drum 20, and the reinforcing rubber members 18 are arranged on both sides at intervals of the tread width from the center, and the center of the carcass 14 is The carcass layer 14 is arranged so as to be located in the center of the outer periphery of the forming drum 20 . At this time, the cords constituting the carcass layer 14 are aligned in the drum width direction. the

Although not shown, the rim strip 17 and the reinforcing layer 16 may be arranged on the outer side of the inner liner rubber 19 in the width direction. The rim strip 17 is preferably arranged such that its end face is in contact with the inner liner rubber 19 or its end is overlapped with the inner liner rubber 19 . the

Next, a step of arranging a pair of the first bead 1a and the bead filler 12 at the arrangement position of the first bead 1a in the carcass layer 14 is implemented. The first bead 1a and the bead filler 12 may be arranged sequentially over the carcass 14, but it is preferable to arrange the structure in which both the first bead 1a and the bead filler 12 are integrally formed. the

Next, as shown in FIG. 7( b ), the end portion of the carcass 14 is rolled up and pasted, but this step may be performed after the step of deforming the molded product into a ring shape. Through this pasting step, the first bead 1 a and the bead filler 12 are formed into a shape sandwiched by the rolled carcass 14 . the

Next, as shown in FIG. 7( c ), a step of deforming the portion inside the first bead 1 a of the obtained molded product into a ring shape is carried out. Through this process, a ring-shaped molded product is formed. This deformation can be performed by forming drums 20 . At this time, a bead locking mechanism may be provided in advance on the forming drum 20, and the bead portion 1a may be clamped from the inner peripheral side of the tire by the rim strip 17, the ply 14, and the like. Thus, deformation can be performed with high precision. the

Next, as shown in FIG. 7( c ), the rubber member 13 constituting the annular bulge is attached to the side of the rubber filler 12 of the annular molding, but this step can be performed in the same manner as in the above-mentioned embodiment. the

In addition, as shown in FIG. 7( d ), the second bead 1b is formed by affixing the cord BW to the above-mentioned rubber member 13 in a spiral shape while rotating the affixed molded product around the axis. It can be performed in the same manner as in the above-mentioned embodiment. the

(2) In the above-mentioned embodiment, when attaching the cord in a spiral shape, 5 turns are attached to the first surface, 4 turns are attached to the next surface, and then 3 turns and 2 turns are pasted. As shown in Fig. 8, when the cord BW is adhered in a spiral shape to form the second bead 1b, various methods can be adopted. the

The shapes shown in the illustration are all shapes (trapezoid or triangle) with fewer turns as they get closer to the upper layer, but they can also be a quadrilateral shape in which the number of turns in each layer is equal, or the number of turns is increased at one end and then decreased. shape (6-gon or 8-gon), etc. the

As the shape of the above-mentioned second bead, a trapezoidal shape is particularly preferable from the viewpoint of preventing bead dropout, rim assembly performance, workability, and weight reduction. the

(3) In the above-mentioned embodiments, an example was shown in which one layer of sheet or plate-like material was used for molding as the inner liner rubber, reinforcing rubber member, rim strip, sidewall rubber, and tread rubber, etc., However, these members are obtained by winding a continuous rubber belt into a spiral shape to obtain a predetermined shape, so they can be arranged (so-called glue supply method). the

Specifically, the members can be arranged by the glue supply method by rotating the forming drum or the molded product around the axis, discharging the rubber strip from the rubber extruder and sticking it, and moving the sticking position. Various methods are known for this glue supply method, and any of these methods can be adopted. the

(4) In the above-mentioned embodiment, the example in which the rim strip and the reinforcing layer are arranged in advance on the outer side of the inner liner rubber of the forming drum in the width direction is shown; The rubber member constituting the ring-shaped bulge is pasted, and then rolled up after arranging the rim strip and the reinforcing layer. the

According to this manufacturing method, the process of rolling up the carcass layer and the process of rolling up the rim strip and the reinforcing layer can be sequentially performed using a rubber bladder called an air bag. the

Embodiment of the second invention

Next, embodiments of the second invention will be described with reference to the drawings. Fig. 9 is a tire meridian cross-sectional view showing an example of a run-flat tire according to the second invention, and Fig. 10 is a main part cross-sectional view schematically showing a bead portion. 11 to 13 are process diagrams showing an example of the production method of the second invention. the

The method for manufacturing a run-flat tire according to the second invention includes the steps of arranging an inner liner rubber, a reinforcing rubber member for reinforcing sidewall portions on both sides, and a carcass layer at predetermined positions on the outer periphery of a building drum; A pair of first beads and a filler strip are arranged, and the inner portion of the first bead is deformed into a ring shape; before or after the deformation, the end of the above-mentioned carcass is rolled up and pasted. Thus, a ring-shaped molded product was obtained. The manufacturing method of the second invention further includes: adhering a rubber member constituting the annular bulging portion to the side of the above-mentioned rubber filler of the annular molded product; The reinforcing layer is formed by being spirally pasted on the area of the rubber member facing the rim flange. the

As shown in FIGS. 11 to 13 , this embodiment shows an example in which the above-mentioned ring-shaped molded product is formed through the following steps: the inner liner rubber 19 and the tires for reinforcing the tires on both sides are respectively arranged at predetermined positions on the outer periphery of the forming drum 20 ; The reinforcing rubber member 18 of the side portion, and the carcass layer 14 in which the cords are arranged in the width direction is respectively arranged on the outer side than the vicinity of the outer end of each reinforcing rubber member 18 in the drum width direction; A pair of first bead 1a and filler strip 12 are arranged at a position slightly outside the inner end in the width direction of the drum; the part inside the first bead 1a of the obtained molded product is deformed into a ring shape; The outer end 14b of the carcass 14 is rolled up toward the outer peripheral side of the deformed molded product and stuck thereto. the

First, a run-flat tire according to the second invention obtained by the present embodiment will be described. the

The run-flat tire of the second invention

As shown in FIGS. 9 to 10 , the run-flat tire according to the second invention has a pair of bead portions 1, a sidewall portion 2, and a tread portion 3. The sidewall portions 2 extend from the bead portion 1 to the tire radial direction. Extending outward, the tread portion 3 is provided between the sidewall portions 2 . In the bead portion 1, a bead 1a (corresponding to the above-mentioned first bead) formed by forming a bead wire bundle into a ring in the tire circumferential direction is arranged, and a cross-sectional bead is arranged on the tire outer periphery of the bead 1a. A triangular filler strip 12 extending radially of the tire. In addition, it is preferable to arrange a rim strip 17 having excellent wear resistance at a portion directly in contact with the rim 8 . the

The carcass layer 4 is composed of a carcass layer 14 formed by arranging cords at an angle of approximately 90° to the tire equator line C, and provided respectively for the pair of bead portions 1 . In this embodiment, an example is shown in which one end 14a of the carcass layer 14 is rolled up from the outside to the inside of the first bead 1a, and the other end 14b is arranged inside the belt layer 6 . the

In the present embodiment, the other end 14b of the carcass layer 14 is preferably disposed within a range of 60 to 90% of the width of both outer sides of the widest layer (usually the innermost layer) of the belt layer 6 . Thereby, while maintaining the tire reinforcing effect by the cooperation of the carcass layer 14 and the belt layer 6 , the weight of the tire can be reduced, and the rolling resistance and riding comfort can be improved. the

On the inner peripheral side of the carcass layer 4, an inner liner 5 for maintaining air pressure is arranged, and on the tire inner peripheral side of the tread portion 3, a belt layer 6 for reinforcement by a hoop effect and, if necessary, a belt layer 6 are arranged. Reinforce the belt layer 7 . The belt layer 6 is composed of sub-belt layers in which cords are arranged at a predetermined angle to the tire equator line C and in parallel. the

In addition, as the bead wire, a steel wire or the like can be used, and as the cords constituting the carcass layer 4 and the belt layer 6, organic fibers such as steel, polyester, rayon, nylon, and aramid can be used. In order to improve the adhesiveness of all these cords to rubber, they are usually subjected to surface treatment, bonding treatment, and the like. the

A sidewall rubber 11 is arranged on the outer side of the sidewall portion 2 , and a reinforcing rubber layer 9 having a substantially crescent-shaped cross section is arranged on the inner side of the sidewall portion 2 . As a result, when the air pressure inside the tire decreases, the bending deformation of the tire can be suppressed, and run-flat running can be performed. The reinforcing rubber layer 9 is constituted by, for example, a rubber layer having a rubber hardness (rubber hardness measured in accordance with JIS K6253 Type A Durometer hardness test, the same below) of 65° to 90°. In addition, the reinforcing rubber layer 9 of the run-flat tire of the second invention can be applied as long as it is a reinforcing rubber layer used in conventional side-reinforced run-flat tires, and the hardness, thickness, etc. are not particularly limited. . The reinforcing rubber layer 9 is not limited to a structure consisting of a single rubber layer, but may also be a structure composed of multiple rubber layers having different physical properties such as hardness. the

In the second invention, as shown in FIG. 10 , there is further provided an annular bulging portion 10 that bulges outward in the tire width direction from at least one bead portion 1 and has a second bead 1b. . The annular bulging portion 10 bulges outward in the tire width direction from the rim flange 8a, and has an inner peripheral surface extending along the outer peripheral side curved surface of the rim flange 8a. As a result, the annular bulging portion 10 can effectively embrace the rim flange 8a, thereby preventing bead slipping. The annular bulging portion 10 is preferably formed on each of the bead portions 1 on both sides. the

A bead 1b (corresponding to the above-mentioned second bead) in which a bead wire is annularly formed in the tire circumferential direction is arranged in the annular bulging portion 10 . The bead 1b of the present embodiment is arranged such that its center position is located on the tire outer peripheral side and outside in the tire width direction from the outermost radial point of the rim flange 8a when mounted on a rim. In addition, in the second invention, the arrangement position of the bead 1b is not particularly limited. the

The run-flat tire according to the second invention is characterized in that a reinforcing layer 16 in which cords SC are helically arranged is provided in a region of the annular bulging portion 10 facing the rim flange, and the self- The continuous cord SC of the reinforcement layer 16 is wound helically to form the second bead 1b. the

The reinforcement layer 16 is disposed substantially along the inner peripheral surface of the annular bulging portion 10 , thereby reinforcing the inner peripheral surface of the annular bulging portion 10 and suppressing abrasion. Examples of the cord SC constituting the reinforcing layer 16 and the second bead 1b include organic fibers such as steel cords, rayon, nylon, polyester, and aramid. the

As shown in FIG. 10 , the carcass layer 14 is rolled up from the outside to the inside at the bead portion 1 a , and one end 14 a thereof is disposed near the bottom of the bead filler 12 . The height H of the bead filler 12 can vary, for example, within the range of 15 to 65 mm. However, from the viewpoint of tire durability and weight reduction, it is preferable to place the end 14a of the carcass 14 on the basis of the tire outer peripheral end of the bead 1a. The height P is made into the range of 10-20 mm. the

In addition, the cross-sectional shapes of the annular bulging portion 10, the annular rubber portion 13, and the filler strip 12 of the run-flat tire obtained by the second invention are not limited to those shown in this embodiment. the

Method for Manufacturing Run-flat Tire of Second Invention

Next, a method of manufacturing a run-flat tire according to the second invention will be described with reference to FIGS. 11 to 13 . The difference between the steps shown in Figures 11(a) to 12(b) of the second invention and the steps shown in Figures 3 to 4 of the first invention is only that in Figures 11(a) to 12(b) There is no reinforcement layer 16 in this point. First, the same cylindrical molding drum 20 as that of the first invention is prepared. the

Next, as shown in FIG. 11( a ), a process of arranging the inner liner rubber 19 , the reinforcing rubber member 18 for reinforcing both sidewall portions, and the carcass 14 at predetermined positions on the outer periphery of the forming drum 20 is carried out. Specifically, the same steps as those of the first invention can be employed. the

Next, as shown in FIG. 11( b ), a step of arranging the pair of first beads 1 a and the bead filler 12 slightly outside the inner end in the drum width direction of the carcass layer 14 is carried out. Specifically, the same steps as those of the first invention can be employed. the

Next, as shown in FIG. 11( c ), a step of deforming the portion inside the first bead 1 a of the obtained molded product into a ring shape is carried out. Specifically, the same steps as those of the first invention can be employed. the

Next, as shown in FIG. 12( a ), a step of rolling up the outer end (the other end 14 b ) of each carcass layer 14 toward the outer peripheral side of the deformed molded product and affixing it to the outer peripheral side is carried out. Through this process, a ring-shaped molded product is formed. Specifically, the same steps as those of the first invention can be employed. the

At this time, the carcass layers 14 may be individually or collectively rolled up by hand in a state in which the bead 1a is fixed by the bead lock mechanism as needed. In addition, the ply 14 can be easily rolled up by assembling a rubber bladder called an air bladder to apply internal pressure. At this time, in order to wind up the rim strip 17 at the same time, a spacer may be inserted between the rim strip 17 and the carcass 14 in advance, and the next step may be performed after peeling off the rim strip 17 and the like. the

As shown in FIG. 12( b ), the second invention includes the step of sticking the rubber member 13 constituting the annular bulging portion to the side of the rubber filler 12 of the annular molding. The annular rubber body 13 is composed of the same type or two or more types of rubber members 13a, 13b, and the like. The annular rubber body 13 preferably has a rubber hardness of 40-75°, for example, and has sufficient rigidity and crack resistance to withstand repeated impacts transmitted from the rim 8 . The annular rubber body 13 is stuck on the outer side of the bead filler 12 in the tire width direction with the carcass layer 14 interposed therebetween. the

As shown in FIG. 12(c), the second invention involves sticking the cord SC in a helical shape in the region of the rubber member 13 facing the rim flange while rotating the pasted molded product around the axis. And the process of forming the reinforcing layer 16 . In this embodiment, an example is shown in which the reinforcement layer 16 is formed by affixing the cord SC in a spiral form from the tire inner peripheral side to the outer peripheral side. The second bead 1b is formed by affixing the cord SC continuous from the reinforcement layer 16 to the rubber member 13 in a spiral shape while the core is rotated. Figures 13(a) to (c) show these steps in more detail. the

One or a plurality of cords SC may be bonded together, but it is preferable to bond one cord SC from the viewpoint of uniformity, strength, productivity, and the like. As the material of the cord SC, steel wires, steel cords, organic fibers such as polyester, rayon, nylon, and aramid, and the like can be used. That is, in the conventional method, it was difficult to maintain the annular shape with organic fibers because the annular bead was manufactured in advance, but in the second invention, the uniformity is good even if the organic fibers are used because they are bonded. the

In addition, it is preferable to use a cord coated with an unvulcanized rubber from the viewpoint of facilitating bonding between the cords. Examples of the unvulcanized rubber include those used in the production of the first bead, for example, rubber having a rubber viscosity of 50 to 80 is used. Here, the rubber viscosity is a value measured in accordance with the "Mooney viscosity test" in the "Physical testing methods for unvulcanized rubber" of JIS K6300. the

In the second invention, as shown in FIG. 13( a ), when forming the reinforcing layer 6 , it is preferable to stick the cord SC on the same surface in a spiral shape first. In the illustrated example, as shown by the arrow, first, the cord SC is pasted in a spiral form from the inner peripheral side to the outer peripheral side, but when the reinforcing layer 16 and the second bead 1b are formed discontinuously, they may be attached to the outer peripheral side. Paste in the direction opposite to the direction of the arrow. the

In the manufacturing method of the second invention, when the reinforcement layer 16 is formed, the region to which the cord SC is pasted should only include a part or the whole of the region facing the rim flange, for example, it may be extended to the second The side or bottom of the first bead 1a, or extends to the side of the second bead 1b. In addition, when the cord SC is pasted in a spiral shape, the pitch (center-to-center distance) of the cord SC is preferably 1.5 to 3 mm. When the pitch is larger than this range, there is a tendency for the resistance effect against bead fall to decrease. the

In addition, when forming the second bead 1b, the cord SC may be pasted in a helical shape, and the cord SC may be arbitrarily wound (helical winding is also included here), but as shown in FIG. 13(b), Preferably, the cord SC is attached to the same surface in a spiral form first. Moreover, it is preferable to repeat the process of affixing the cord BW to the upper surface in a spiral shape next, as shown in FIG.13(c). the

In this embodiment, when forming the second bead 1b, 5 turns of the cord SC are attached in a spiral shape on the first surface, 4 turns are attached to the next surface, and then 3 turns and 2 turns are attached. By gradually reducing the number of turns in this way, it is easy to maintain the shape of the second bead 1b after the vulcanization step. In addition, by affixing two or more turns to the uppermost layer, it is also easy to maintain the shape of the second bead 1b after the vulcanization step. In addition, after the cord BW is pasted in a spiral on the same surface, return it, and then paste it in a spiral on the upper surface, the cord SC can be pasted in a spiral along the concave portion formed by the two cords. shape. the

Next, as shown in FIG. 12( c ), the rim strip 17 is rolled up and attached to a predetermined position. Further, the sidewall rubber 11 is arranged along the outer peripheral surface of the annular rubber body 13 from the annular bulging portion 10 toward the sidewall portion 2 . Thereafter, the belt layer 6 and the reinforcing belt layer 7 are formed on the tire outer peripheral side of the molded body, and tread rubber is arranged on the outer peripheral side to form the tread portion 3. the

Other embodiments of the second invention

(1) In the above-mentioned embodiment, two layers of carcass are used, and the outer end of each carcass mentioned above is rolled up and pasted to form a ring shape in which the other end of the carcass is rolled up from the outside to the inside. However, a run-flat tire having the same carcass structure as the conventional one shown in FIG. 14 can be manufactured using one carcass ply. Even in this case, in the same manner as in the above-described embodiment, the cord SC can be adhered in a helical shape in the area of the rubber member 13 facing the rim flange while rotating the molded product around the axis. A process of forming the reinforcement layer 16 . the

That is, as shown in FIGS. 15( a ) to ( c ), the second invention may include the steps of disposing inner liner rubber 19 at predetermined positions on the outer periphery of the building drum 20, and rubber for reinforcing the sidewall portions on both sides. Reinforcing rubber member 18, and carcass layer 14; a pair of first bead 1a and filler strip 12 are arranged, and the part inside the first bead 1a is deformed into a ring shape; before or after the deformation, the above-mentioned The ends of the ply 14 are glued. the

Specifically, the steps shown in FIGS. 15( a ) to ( c ) can be the same steps as the steps shown in FIGS. 7( a ) to ( c ) of the first invention. the

In addition, as shown in FIG. 15( d ), while rotating the pasted molded product around the axis, the cord SC is pasted in a spiral shape in the area of the rubber member 13 facing the rim flange to form reinforcement. layer 16, and this step and subsequent steps can also be performed in the same manner as in the above-mentioned embodiment. the

(2) In the above-mentioned embodiment, an example was shown in which the reinforcing layer and the second bead are continuously formed with continuous cords, but the reinforcing layer and the second bead may be formed with other cords. In this case, for the second bead, it is also possible to use a member that is separately made into a bead wire assembly by helically winding the bead wire as in the conventional method. the

(3) In the above-mentioned embodiment, when forming the second bead 1b and attaching the cord in a spiral shape, 5 turns of the cord SC are attached to the first surface, 4 turns are attached to the next surface, and then In the example of pasting three turns and two turns, when the cord SC is pasted in a spiral shape to form the second bead 1b, various forms can be adopted as shown in FIG. 8 . the

(4) In the above-mentioned embodiments, examples were shown in which one layer of sheet or plate-like material was used as the inner liner rubber, reinforcing rubber member, rim strip, sidewall rubber, and tread rubber. All the components can be arranged by winding a continuous rubber belt into a spiral shape to obtain a predetermined shape (the so-called glue supply method). Specifically, the same steps as those in other embodiments of the first invention can be employed. the

(5) In the above-mentioned embodiment, the example in which the rim strip is arranged in advance on the outer side of the inner liner rubber of the forming drum in the width direction is shown; The rubber member of the shaped bulge is then rolled up after being fitted with the rim strip. the

According to this manufacturing method, the process of rolling up the carcass layer and the process of rolling up the rim strip and the reinforcement layer can be sequentially performed using a rubber bladder called an air bag. the

Claims (6)

1. A method for manufacturing a run-flat tire, comprising the following steps: In the specified positions on the outer periphery of the building drum, the inner layer rubber, the carcass layer and the reinforcing rubber members for strengthening the sidewalls on both sides are arranged respectively; A pair of first beads and filler strips are arranged to deform the inner part of the first bead into a ring shape; before or after this deformation, rolling up the end of the above-mentioned ply and gluing the end; Paste the rubber member constituting the ring-shaped bulging part on the side of the above-mentioned filling rubber strip of the ring-shaped molding; While rotating the pasted molded product around the axis, the cord is pasted on the rubber member in a spiral shape to form a second bead; The above-mentioned ring-shaped molding is formed by the following steps: Inner liner rubber and reinforcing rubber members for reinforcing the sidewalls on both sides are arranged at predetermined positions on the outer periphery of the building drum, and curtains are respectively arranged on the outer side of each reinforcing rubber member near the outer end in the drum width direction. Ply with lines arranged along the width direction; A pair of first beads and filler strips are arranged at a position slightly outside the inner end of the ply in the drum width direction; deforming the part of the obtained molded product inside the first bead into a ring shape; The outer end of each of the above-mentioned carcass layers was rolled up toward the outer peripheral side of the deformed molded product and stuck to the outer peripheral side. 2. The method of manufacturing a run-flat tire according to claim 1, wherein: The above-mentioned cords are cords coated with unvulcanized rubber. After the cords are pasted in a spiral shape on the same surface, the cords are repeatedly pasted in a spiral shape on the upper surface of the previous cord layer. process. 3. A method for manufacturing a run-flat tire, comprising the following steps: In the specified positions on the outer periphery of the building drum, the inner layer rubber, the carcass layer and the reinforcing rubber members for strengthening the sidewalls on both sides are arranged respectively; A pair of first beads and filler strips are arranged to deform the inner part of the first bead into a ring shape; before or after this deformation, rolling up the end of the above-mentioned ply and gluing the end; Paste the rubber member constituting the ring-shaped bulging part on the side of the above-mentioned filling rubber strip of the ring-shaped molding; While rotating the pasted molded product around the axis, the cord is pasted in a spiral shape on the area facing the rim flange of the above-mentioned rubber member to form a reinforcing layer; The above-mentioned ring-shaped molding is formed by the following steps: Inner liner rubber and reinforcing rubber members for reinforcing the sidewalls on both sides are arranged at predetermined positions on the outer periphery of the building drum, and curtains are respectively arranged on the outer side of each reinforcing rubber member near the outer end in the drum width direction. Ply with lines arranged along the width direction; A pair of first beads and filler strips are arranged at a position slightly outside the inner end of the ply in the drum width direction; deforming the part of the obtained molded product inside the first bead into a ring shape; The outer end of each of the above-mentioned carcass layers was rolled up toward the outer peripheral side of the deformed molded product and stuck to the outer peripheral side of the molded product. 4. The method for manufacturing a run-flat tire according to claim 3, wherein the method for manufacturing the run-flat tire comprises the following steps: The above-mentioned cord is pasted in a spiral form from the inner peripheral side to the outer peripheral side of the tire to form the above-mentioned reinforcing layer. The second bead is formed by sticking it spirally on the above-mentioned rubber member. 5. The method of manufacturing a run-flat tire according to claim 4, wherein: The above-mentioned cords are cords coated with unvulcanized rubber. After the above-mentioned cords are attached to the same surface in a spiral shape in the process of forming the above-mentioned second bead, the above-mentioned cord layer is then repeatedly applied to the previous cord layer. The process of sticking the cord on the surface in a spiral shape. 6. A run-flat tire manufactured by the method of claim 1 or 3, comprising a bead portion, a sidewall portion, a tread portion, a belt layer, a carcass layer, a reinforcement rubber layer and annular bulge; The bead portions are a pair, and have an annular first bead and a filler strip disposed on the tire outer peripheral side of the first bead, and the sidewall portions respectively extend outward in the tire radial direction from the bead portions, The tread portion is provided between the sidewall portions, the belt layer is provided on the tire inner peripheral side of the tread portion, the carcass layer is composed of carcass wound around the first bead, and the reinforcing rubber layer is Arranged on the sidewall portion, the annular bulging portion bulges outward in the tire width direction from the bead portion and has a second bead; Wherein, a reinforcing layer in which cords are arranged in a helical shape is provided in a region of the annular bulge facing the rim flange, and the cords continuously extending from the reinforcing layer are wound in a helical shape. shape to form the above-mentioned second bead.

Images