JP5281671B2 - Shaping former for run-flat tires - Google Patents

Description

  The present invention relates to a shaping former for run flat tires that can improve productivity.

  For example, various run-flat tires have been proposed that can travel relatively long distances (hereinafter, such travel is simply referred to as “run-flat travel”) even in a state in which the air in the tire has escaped due to puncture or the like. Yes. As a typical one, a side reinforcing type in which a rubber reinforcing layer having a substantially crescent-shaped cross section is provided on the side wall is well known.

  As a process for manufacturing such a run-flat tire, first, as shown in FIG. 12A, a cylindrical molding drum d, a sheet-like inner liner rubber i, a pair of rubber reinforcing layers g, a sheet After the cylindrical carcass ply c is wound sequentially, the bead core b and the bead apex rubber e are inserted to form the cylindrical carcass base a.

  Next, as shown in FIG. 12B, the carcass base a is moved to the shaping former f, and both end portions of the carcass ply c are folded back from the outside in the axial direction, and then sheet-like side wall rubber is obtained. s is wound.

  Thereafter, the carcass base a is inflated and deformed (shaped) in a toroidal shape in accordance with conventional practice, and a tread ring including a belt ply and a tread rubber is bonded to the outer peripheral surface to form a raw tire (not shown). The A run flat tire is manufactured by vulcanization-molding this raw tire. Related documents include the following (see Patent Document 1 below).

JP 2010-36420 A

  By the way, in the shaping former f as described above, the outer peripheral surfaces of the side decks f1 and f1 that support the side wall rubber s of the carcass base are formed flat, while the rubber reinforcing layer g has a substantially crescent-shaped cross section. It has a relatively large thickness.

  For this reason, since the outer surface of the rubber reinforcing layer g around which the sidewall rubber s is wound has large irregularities, when the sidewall rubber s is wound, wrinkles, air confinement, etc. are likely to occur, resulting in productivity. There was a problem of getting worse. In addition, there is a problem in that such entrapped air causes defective vulcanization such as defects.

  The present invention has been devised in view of the actual situation as described above, and a circumferential groove recessed in accordance with the cross-sectional shape of the rubber reinforcing layer is formed on the outer peripheral surface of the side deck that supports the sidewall portion of the carcass base from the inside. The main object is to provide a shaping former for run-flat tires that can improve productivity on the basis of forming.

  The invention according to claim 1 of the present invention includes a pair of bead cores and a cylindrical unvulcanized carcass ply, and a rubber reinforcing layer for run flat running is disposed on each side wall portion of the carcass ply. A shape former for a run-flat tire for inflating and deforming a carcass base in a toroidal shape, a pair of side decks capable of expanding and contracting and capable of supporting a side wall portion of the carcass base from the inside, and the side deck A pair of bead lock means that can hold the bead core from the inside via the carcass ply and can move in the axial direction, and the outer peripheral surface of the side deck includes the rubber reinforcing layer. A circumferential groove that is recessed according to the cross-sectional shape is formed.

  A shaping former for a run-flat tire according to the present invention includes a pair of bead cores and a cylindrical unvulcanized carcass ply, and a rubber reinforcing layer for run-flat running is disposed on each side wall portion of the carcass ply. The carcass substrate is used to expand and deform into a toroidal shape.

  This shaping former has a pair of bead lock means that can hold the bead core from the inside via the carcass ply and can move in the axial direction by expanding the diameter, and is located on the inner side in the axial direction of the bead lock means and on the carcass base. And a pair of side decks capable of expanding and contracting to support the sidewall portion from the inside.

  Moreover, the outer peripheral surface of the side deck is formed with a circumferential groove that is recessed according to the cross-sectional shape of the rubber reinforcing layer. Such a side deck can absorb the thickness of the rubber reinforcing layer and can hold the outer surface of the carcass base around which the side wall rubber is wound in a flat state. As a result, when the sidewall rubber is wound, it is possible to prevent winding defects such as wrinkles and air confinement, and to improve productivity. In addition, since air confinement can be suppressed, defective vulcanization such as defects can be prevented.

It is a top view which shows the manufacturing line in which the shaping former of this invention was integrated. (A) is sectional drawing which shows a forming drum, (b) is sectional drawing which shows the forming drum which made the circumferential groove | channel appear. (A)-(c) is sectional drawing which shows the shaping | molding method of a carcass base | substrate. It is sectional drawing which shows the shaping former of this embodiment. FIG. 5 is an enlarged view of FIG. 4. It is sectional drawing perpendicular to the axial direction which shows the side deck expanded and contracted in the radial direction. It is sectional drawing which shows the side deck expanded radially and the bead lock ring. (A) is a cross-sectional view illustrating a step of locking the bead core, and (b) is a cross-sectional view illustrating a step of sinking the rubber reinforcing layer into the circumferential groove of the side deck. (A)-(c) is sectional drawing explaining the process in which bead apex rubber is laid down. It is sectional drawing explaining the process of winding side wall rubber. It is sectional drawing of the run flat tire manufactured with the shaping former of this embodiment. (A), (b) is sectional drawing explaining the process of forming the conventional carcass base | substrate and a green tire.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 11, a shaping former 12 for a run-flat tire (hereinafter, simply referred to as “shaping former”) 12 according to the present embodiment passes through a sidewall portion 3 from a tread portion 2 and a bead portion 4. A carcass 6 reaching the bead core 5, a belt layer 7 disposed on the outer side in the tire radial direction of the carcass 6 and on the inner side of the tread portion 2, and a rubber reinforcing layer disposed on the inner side of the carcass 6 of each sidewall portion 3. 9 and a run-flat tire 1 for a passenger car comprising an inner liner rubber 10 disposed inside the carcass 6 or the rubber reinforcing layer 9.

  The carcass 6 is composed of one or more radial structures in which carcass cords are arranged at an angle of, for example, 70 to 90 degrees with respect to the tire equator C, and in this embodiment, one carcass ply 6A. As the carcass cord, for example, an organic fiber cord such as polyester, nylon, rayon, or aramid, or a steel cord as necessary is adopted.

  Further, the carcass ply 6A is folded from the inner side to the outer side in the tire axial direction around the bead core 5 and the main body part 6a extending from the tread part 2 through the sidewall part 3 to the bead core 5 of the bead part 4 and the main body part 6a. And the folded portion 6b. A bead apex rubber 8 made of hard rubber extending from the bead core 5 to the outside in the tire radial direction is disposed between the main body portion 6a and the folded portion 6b of the carcass ply 6A, and the bead portion 4 is appropriately reinforced.

  In the present embodiment, the folded portion 6b of the carcass 6 rolls up over the bead apex rubber 8 radially outward, and its outer end portion 6be is sandwiched between the main body portion 6a and the belt layer 7 and terminates. It has a so-called ultra-high turn-up folding structure. Thereby, the side wall part 3 is effectively reinforced using one carcass ply 6A.

  The belt layer 7 includes at least two belt plies 7A and 7B in which the belt cord is arranged at a small angle of, for example, 10 to 35 degrees with respect to the tire equator C. Are superimposed in the direction in which the cords cross each other. The belt cord of this embodiment employs a steel cord, but a highly elastic organic fiber cord such as aramid or rayon can also be used as necessary.

  The rubber reinforcing layer 9 is made of, for example, hard rubber having a rubber hardness of about 60 to 95 degrees, and is continuously arranged in the tire circumferential direction on the inner side in the tire axial direction of the carcass 6 and on the outer side in the tire axial direction of the inner liner rubber 10. Is done. The rubber reinforcing layer 9 has a cross section in which the thickness r measured in the normal direction with respect to the main body portion 6a of the carcass ply 6A gradually decreases from the central portion toward the inner end 9i and the outer end 9o in the tire radial direction. It is formed in a nearly crescent shape. “Rubber hardness” is the hardness according to durometer type A in an environment of 23 ° C. in accordance with JIS-K6253.

  The inner liner rubber 10 is disposed in a toroid shape so as to straddle between the bead portions 4 and 4 in order to retain air in the tire lumen i, and forms a main portion of the tire lumen surface. For the inner liner rubber 10, for example, a rubber composition having gas barrier properties such as butyl rubber, halogenated butyl rubber and / or brominated butyl rubber is used.

  FIG. 1 shows a production line L in which the shaping former 12 of the present invention is incorporated.

  The production line L includes a forming drum 11 that forms a carcass base 1M in which a rubber reinforcing layer 9 is disposed on each sidewall portion 3 of the carcass ply 6A, and a shaping former 12 that expands and deforms the carcass base 1M in a toroid shape. including.

  Further, the belt ply 7 that forms the tread ring 2R by winding the belt plies 7A and 7B and the tread rubber 2G, the belt plies 7A and 7B, and the tread rubber 2G are supplied to the belt drum 13 in the production line L. Devices 14 and 15, and devices 16 and 17 for supplying the carcass ply 6 </ b> A, the rubber reinforcing layer 9, and the inner liner rubber 10 to the molding drum 11 are included. Further, a first transfer 18 that conveys the carcass substrate 1M is disposed between the forming drum 11 and the shaping former 12, and a tread ring 2R that conveys the tread ring 2R between the belt drum 13 and the shaping former 12 is disposed. Two transfers 19 are arranged.

  As shown in FIGS. 2A and 2B, the forming drum 11 of the present embodiment includes a carcass ply 6A and a cylindrical drum body 21 around which the rubber reinforcing layer 9 is wound.

  The drum body 21 includes a central segment 21A, a pair of side segments 21B and 21B disposed on both sides of the central segment 21A, and a segment support portion 21C that supports these from the inside in the radial direction. Further, the side segments 21B and 21B are slidably supported on the outer peripheral surface of the segment support portion 21C.

  As shown in FIG. 2A, the molding drum 11 has a cylindrical smooth outer peripheral surface 11S formed by bringing the central segment 21A and the side segment 21B into contact with each other in the axial direction. . Further, as shown in FIG. 2 (b), the forming drum 11 has a substantially inverted cross section that is continuous with the outer circumferential surface in the tire circumferential direction by separating the central segment 21A and the side segment 21B in the axial direction. A circumferential groove 22 of shape can appear. The circumferential groove 22 has substantially the same volume as the rubber reinforcing layer 9 (shown in FIG. 1).

A method for forming the carcass substrate 1M using the forming drum 11 of the present embodiment will be described.
As shown in FIG. 3A, in the state where the cylindrical drum outer peripheral surface 11S is formed, the inner drum rubber 10 and the rubber reinforcing layer 9 are sequentially wound around the outer peripheral surface 11S. Is done. As a result, a first cylindrical object 1N including a cylindrical inner liner rubber 10 and a rubber reinforcing layer 9 protruding radially outward from the inner liner rubber 10 is formed on the molding drum 11.

  As shown in FIG. 3 (b), the molding drum 11 is formed in a state where the rubber reinforcing layer 9 of the first cylindrical object 1N is plastically deformed in a state where the circumferential groove 22 appears on the outer peripheral surface. Sink into the directional groove 22. Since the circumferential groove 22 has substantially the same volume as the rubber reinforcing layer 9, the rubber reinforcing layer 9 can sink the rubber reinforcing layer 9 uniformly, and the outer peripheral surface of the first cylindrical object 1N. Can be flattened.

  As shown in FIG. 3C, a sheet-like carcass ply 6A and a bead assembly 5C composed of a bead core 5 and a bead apex rubber 8 are sequentially formed on the flat outer peripheral surface of the first cylindrical object 1N. Wrapped. Thereby, the carcass base 1M in which the rubber reinforcing layer 9 protrudes in a substantially inverted trapezoidal shape inward in the radial direction is formed. As shown in FIG. 1, the carcass base 1 </ b> M is conveyed to the shaping former 12 by the first transfer 18.

  Thus, since the molding drum 11 of this embodiment can wind the carcass ply 6A around the flat outer peripheral surface of the first cylindrical object 1N, the winding accuracy of the carcass ply 6A is improved, and the bead cores 5, 5 The length of the carcass cord extending in the area between them (hereinafter sometimes simply referred to as “carcass cord path”) can be made uniform in the tire circumferential direction, and the uniformity can be greatly improved.

  As shown in FIG. 4, the shaping former 12 of the present embodiment includes a central drum mechanism 31 including a pair of side decks 38 capable of expanding and contracting and capable of supporting the vicinity of the sidewall portion 3 of the carcass base 1M from the inside, A pair of bead locking means 32 that is located on the outer side in the axial direction of the side deck 38 and can hold the bead core 5 from the inner side via the carcass ply 6A, and a bead apex rubber folding means 33 having an inflatable bladder 61 are provided. Including.

  The central drum mechanism 31 is held via a drum shaft 36, a rotating cylinder 37 concentrically arranged on the outer side in the radial direction of the drum shaft 36, and a first horizontal slide cylinder 43 on the rotating cylinder 37. The side deck 38 is composed of a pair of left and right drum bodies, guide means 39 for guiding the side deck 38 inward and outward in the radial direction, and first expansion / contraction diameter means 40 for expanding and contracting the side deck 38.

  Further, in the present embodiment, a first drive motor (not shown) is connected to one end of the drum shaft 36, and a second drive motor (not shown) is connected to one end of the rotating cylinder 37. As a result, the drum shaft 36 and the rotary cylinder 37 can rotate independently of each other.

  The drum shaft 36 is formed on both sides with a right screw portion 36A in which a right screw is screwed and a left screw portion 36B in which a left screw is screwed. Nut fittings 41A and 41B are screwed into the screw portions 36A and 36B.

  The rotary cylinder 37 is formed with elongated guide holes 34A and 34B extending in the axial direction on the outer side in the radial direction of the screw portions 36A and 36B of the drum shaft 36. The guide holes 34A and 34B are provided with moving bodies 42A and 42B which are arranged on the radially outer side of the nut fittings 41A and 41B and which can move in the axial direction while being guided by the guide holes 34A and 34B.

  As shown in an enlarged view in FIG. 5, the moving bodies 42A and 42B are rotated with, for example, a concave locking portion 42a that constrains the movement of the nut fittings 41A and 41B in the axial center direction, and the nut fittings 41A and 41B. For example, a fastener 42b such as a key is provided to restrain the movement in the direction.

  Such moving bodies 42A and 42B are guided by the guide holes 34A and 34B of the rotating cylinder 37 by rotating only the drum shaft 36 while the rotating cylinder 37 is stationary, and the nut fittings 41A and 41B. And move toward or away from each other in the axial direction. Further, the moving bodies 42A and 42B can rotate together with the rotating cylinder 37 while maintaining the position in the axial direction by rotating the drum shaft 36 and the rotating cylinder 37 in the same rotational speed and in the same direction.

  The first horizontal slide cylinder 43 is extrapolated on the outer periphery of the rotary cylinder 37 so as to be slidable in the axial direction, and is integrally connected to the moving bodies 42A and 42B. Accordingly, the first horizontal slide cylinder 43 can move close to or away from the axial direction and rotate in accordance with the movement and rotation of the moving bodies 42A and 42B in the axial direction.

  The side deck 38 is arranged at the inner end in the axial direction of the first horizontal slide cylinder 43, and is divided into a plurality of segments 45 in the circumferential direction.

  As shown in FIG. 6, the segment 45 includes first segments 45A and second segments 45B that are alternately arranged in the circumferential direction. In the present embodiment, the circumferential width of the first segment 45A is formed larger than that of the second segment 45B.

  Further, as shown in FIG. 5, each segment 45A, 45B has a plate-like mounting piece 45C extending radially inward from each inner peripheral surface, and a circumferential groove 45D recessed inward in the radial direction from each outer peripheral surface. And a return spring 45E for urging the mounting piece 45C radially inward. The circumferential groove 45D is formed in a substantially inverted trapezoidal shape in accordance with the cross-sectional shape of the rubber reinforcing layer 9 of the carcass base 1M.

  The guide means 39 includes a disc-shaped side plate 39A attached to the inner end in the axial direction of the first horizontal slide cylinder 43, and a guide extending radially in the axial direction inner side surface of the side plate 39A in the radial direction. Rail 39B. The mounting pieces 45C of the segments 45A and 45B are slidably attached to the guide rail 39B inward and outward in the radial direction.

  The first expansion / contraction diameter means 40 includes a cylinder chamber 46 formed concentrically with the first lateral slide cylinder 43 and extending in the axial direction, and a ring-like shape capable of sliding the cylinder chamber 46 in and out of the axial direction. The piston 47 includes a link 48 having one end pivotally attached to the inner end of the piston 47 in the axial center direction and the other end pivotally attached to the attachment piece 45 </ b> C of the segment 45. The piston 47 can slide in and out in the axial direction by high-pressure air supplied to the cylinder chamber 46.

  As shown in FIG. 6, the link 48 is attached to a first link 48A attached to the first segment 45A having a short radial movement distance and to a second segment 45B having a long radial movement distance. Second link 48B. Further, the distance in the length direction of the first link 48A is formed smaller than that of the second link 48B.

  As shown in FIGS. 6 and 7, such a central drum mechanism 31 moves the piston 47 of the first expansion / contraction diameter means 40 inward in the axial center direction, thereby via the link 48 and the guide means 39. Thus, each segment 45 can be moved radially outward to expand the side deck 38 in diameter.

  As shown in FIG. 6, in the diameter-expanded state Ye of the side deck 38, the first and second segments 45 </ b> A and 45 </ b> B are arranged side by side in the circumferential direction, and one cylindrical surface S <b> 0 substantially continuous in the circumferential direction is formed. It is formed. At this time, the diameter De of the side deck 38 is set larger than the outer diameters of the rubber reinforcing layer 9 and the carcass ply 6A (shown in FIG. 4) of the carcass base 1M.

  Further, the circumferential groove 45D of each segment 45 is formed as a continuous groove that is continuous with the circumferential groove 45D of each segment 45 adjacent in the circumferential direction and has substantially the same volume as the rubber reinforcing layer 9 of the carcass base 1M. The

  Further, the central drum mechanism 31 can reduce the diameter of the side deck 38 by moving each segment 45 radially inward by moving the piston 26 outward in the axial direction.

  In the diameter-reduced state Yr of the side deck 38, the second segment 45B retreats inward in the radial direction from the first segment 45A. At this time, the diameter Dr of the side deck 38 is set smaller than the inner diameters of the rubber reinforcing layer 9 and the carcass ply 6A (shown in FIG. 4) of the carcass base 1M.

  Next, as shown in FIG. 4, the bead lock means 32 includes a second horizontal slide cylinder 51 that is movable in the axial direction on the outer periphery of the first horizontal slide cylinder 43, and the second horizontal slide cylinder 51. A bead lock ring 52 that can be expanded and contracted and is held by a slide cylinder 51 is provided.

  As shown in FIG. 5, the second horizontal slide cylinder 51 includes an airtight air chamber 53 formed between the first horizontal slide cylinder 43 and the axially inner side of the air chamber 53. And a vertical cylinder chamber 55 which is continuous at the inner end in the axial direction of the horizontal cylinder chamber 54 and extends radially outward. The second horizontal slide cylinder 51 can move laterally in the axial direction by supplying high pressure air to the air chamber 53.

  The horizontal cylinder chamber 54 is provided with a piston 56 that can slide inward and outward in the axial direction. The piston 56 has an inclined surface 56S that is inclined inward in the axial direction at the inner end in the axial direction, and is formed in a substantially wedge shape. The piston 56 can move laterally inward in the axial direction by supplying high-pressure air to the horizontal cylinder chamber 54.

  The vertical cylinder chamber 55 is provided with a guide portion 57 including a guide groove extending in the radial direction. The guide portion 57 can guide the bead lock ring 52 inward and outward in the radial direction.

  The bead lock ring 52 includes an inclined surface 52S formed at an inner end portion in the radial direction, a concave groove-shaped core receiving surface portion 52A that receives the inner peripheral surface of the bead core 5, and the bead lock ring 52 in the radial direction. And a return spring 59 biased in the direction.

  The inclined surface 52S of the bead lock ring 52 is formed so as to be inclined radially inward in the axial direction inward, and is arranged in surface contact with the inclined surface 56S of the piston 56 of the horizontal cylinder chamber 54.

  Accordingly, as shown in FIG. 7, when the piston 56 moves laterally inward in the axial direction due to the supply of high-pressure air into the horizontal cylinder chamber 54, the bead lock ring 52 is inclined to each inclined surface 56S, 52S. It can be pushed out in the radial direction via the, and can expand in the radial direction. When the high-pressure air in the horizontal cylinder chamber 54 is exhausted, the bead lock ring 52 is pushed inward in the radial direction by the restoring force of the spring 59. At this time, the piston 56 can move laterally outward in the axial direction via the inclined surface 52S of the bead lock ring 52.

  As shown in FIG. 4, the apex rubber folding means 33 includes an expandable bladder 61 attached to the second lateral slide cylinder 51, and an auxiliary plate 62 that deforms the expanding bladder 61 inward in the axial direction. (Shown in FIG. 9B).

  One end 61 a of the bladder 61 is fixed at a position outside the bead lock ring 52 in the axial direction, and the other end 61 b is fixed at a position inside the bead lock ring 52 in the axial direction. Further, the bladder 61 is folded and held on the outer peripheral surface of the second lateral slide cylinder 51 in the deflated normal state.

  As shown in FIG. 9B, the auxiliary plate 62 is movably disposed on the outer side in the radial direction of the bladder 61 and on the inner side in the axial direction. The auxiliary plate 62 can effectively incline the bead apex rubber 8 by laterally moving in the axial direction while pressing the expanding bladder 61 radially inward.

Next, a method for forming the raw tire 1L using the shaping former 12 of the present embodiment will be described.
In this forming method, as shown in FIG. 1, the step of placing the carcass base 1M on the shaping former 12, the step of locking the bead core 5 by the first transfer 18, and the rubber reinforcing layer 9 of the carcass base 1M. At least a step of sinking the bead apex rubber 8 and a step of winding the sidewall rubber 3G.

  In the step of arranging the carcass base 1M, as shown in FIG. 4, the carcass base 1M is conveyed in a cylindrical shape and transferred onto the outer periphery of the side deck 38 of the shaping former 12.

  In the step of locking the bead core 5, as shown in FIG. 8 (a), the bead lock ring 52 of the bead lock means 32 is expanded in diameter so that the bead assembly 5C and the bead lock 5C are bead-locked. The carcass ply 6A is fixed to the ring 52 while being narrowed. Thereby, since the bead assembly 5C is fixed while the carcass ply 6A is maintained in a cylindrical shape, it is possible to reliably prevent the positional deviation between the bead assembly 5C and the carcass ply 6A, and the carcass cord paths are not varied. Uniform and accurate.

  In the step of sinking the rubber reinforcing layer 9 of the carcass base 1M into the circumferential groove 45D of the side deck 38, the side deck 38 of the central drum mechanism 31 is expanded in diameter as shown in FIG. The 1M rubber reinforcing layer 9 is sunk in the circumferential groove 45D. At this time, in order to surely sink the rubber reinforcing layer 9 into the circumferential groove 45D, the outer surface of the rubber reinforcing layer 9 may be pressed toward the circumferential groove 45D using, for example, a pressing roller (not shown).

  Thereby, the side deck 38 can absorb the thickness of the rubber reinforcing layer 9 by the circumferential groove 45D, and can hold the rubber reinforcing layer 9 and the outer surface of the carcass ply 6A in a flat state. Further, since the carcass ply 6A can be stretched radially outward by expanding the diameter of the side deck 38, the tension of the carcass cord can be given to maintain the uniformity of the cord arrangement.

  In the step of tilting the bead apex rubber 8, as shown in FIG. 9A, the bead lock ring 52 is moved laterally by moving the horizontal slide cylinder 51 of the bead lock means 32 inward in the axial direction. Then, the inner surface in the axial direction of the bead core 5 of the bead assembly 5C is brought into contact with the outer surface in the axial direction of the side deck 38 via the carcass ply 6A.

  Further, as shown in FIGS. 9B and 9C, due to the expansion of the bladder 61, the bead apex rubber 8 is folded down and pressed against the center portion of the carcass ply 6A while folding both end portions of the carcass ply 6A. .

  In this embodiment, after the bladder 61 is inflated, the expanding bladder 61 is deformed inward in the axial direction by the auxiliary plate 62, and the bead apex rubber 8 is brought down and brought into pressure contact with the central portion of the carcass ply 6A. Further, the bead apex rubber 8 and the folded portion of the carcass ply 6A that have been brought down are firmly joined by being pressed using, for example, a pressing roller (not shown).

  As described above, in this embodiment, the bead apex rubber 8 and both end portions of the carcass ply 6A are joined to the flat outer surfaces of the rubber reinforcing layer 9 and the carcass ply 6A, so that air is trapped and wrinkles are generated. It can be effectively suppressed and productivity can be improved. Further, even when both end portions of the bead apex rubber 8 and the carcass ply 6A are joined, the outer surface of the carcass base 1M is maintained flat.

  In the step of winding the sidewall rubber 3G, as shown in FIG. 10, the sheet-like sidewall rubber 3G is wound around the rubber reinforcing layer 9 and the carcass ply 6A in the radial direction. The sidewall rubber 3G is held in a flat state on the outer surface of the carcass base 1M to be wound, so that it is possible to prevent winding defects such as wrinkles and air confinement as in the past, and to improve productivity. Yes. Further, since it is possible to suppress air from remaining between the sidewall rubber 3G and the carcass ply 6A, it is possible to prevent vulcanization defects such as defects.

  Thereafter, as shown in FIG. 1, a step of conveying the tread ring 2R formed in advance by the belt drum 13 to the shaping former 12 using the second transfer 19, and a step of inflating the carcass ply 6A. Done.

  In the step of inflating the carcass ply 6A, the left and right bead lock rings 52, 52 (shown in FIG. 8A) are brought close to each other, and the carcass ply 6A is toroidal between the approaching bead lock rings 52, 52. Inflated into a shape.

  As a result, the toroidal carcass ply 6A is pressure-bonded to the tread ring 2R that has been made to wait in advance, and the raw tire T is formed. The raw tire T is removed from the shaping former 12 due to the reduced diameter of the bead lock ring 52 (shown in FIG. 8A).

  As mentioned above, although especially preferable embodiment of this invention was explained in full detail, this invention is not limited to embodiment of illustration, It can deform | transform and implement in a various aspect.

1M carcass base 5 bead core 6A carcass ply 12 shaping former 32 bead lock means 38 side deck 45D circumferential groove

Claims (1)

A carcass base including a pair of bead cores and a cylindrical unvulcanized carcass ply and having a rubber reinforcement layer for run-flat running on each side wall portion of the carcass ply is expanded and deformed in a toroidal shape. A shaping former for run flat tires of
A pair of side decks capable of expanding and contracting to support the side wall portion of the carcass base from the inside;
A pair of bead lock means located on the outside in the axial direction of the side deck and capable of holding the bead core from the inside via the carcass ply and movable in the axial direction;
A shaping former for a run-flat tire, wherein a circumferential groove that is recessed in accordance with a cross-sectional shape of the rubber reinforcing layer is formed on an outer peripheral surface of the side deck.

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