JP2008221719A - Manufacturing method of pneumatic tire and green tire molding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the undulation apt to occur on the outer surface of a green tire by improving the take-up process of a tire member at the time of molding of the green tire. <P>SOLUTION: This manufacturing method of a pneumatic tire includes the process of winding a tire member 10 in a cylindrical form over a molding drum 2 and the oscillation arm 8 held along an axial direction, the process of fitting a bead core 15 in the tire member 10, the process of expanding the tire member 10 in a toroidal form to form a main body part 20, and the take-up process of taking up a protruded part 21 by the roller 9 of the oscillation arm 8 radially moved toward the main body part 20. The take-up process includes a bead taking-up stage for inclining the side region 20S of the main body part 20 axially inside toward the outside in the radial direction to take up the bead part 21a of the protruded part 21 and a side wall taking-up stage for more raising the side region 20S than the bead taking-up stage to take up the side wall part 21b of the protruded part 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention reduces the undulation that tends to occur on the outer surface of the rolled-up portion by improving the winding process of the tire member at the time of green tire molding, thereby improving the appearance and excellent in uniformity. The present invention relates to a pneumatic tire manufacturing method and a green tire molding apparatus that are useful for providing a tire.

  In a general pneumatic tire manufacturing process, first, after a tire member including a carcass ply is wound around a molding drum in a cylindrical shape, a pair of bead cores are fitted, and the tire member between the bead cores is inflated and deformed in a toroidal shape. The protruding portion of the tire member outside the bead core in the tire axial direction is wound around the bead core to form a raw tire (sometimes referred to as “low cover” or “green tire”), and this is added with a mold. Sulfur molding is performed. And the following patent documents 1 thru | or 3 are proposed as a method of shape | molding a green tire conventionally.

  Patent Document 1 discloses a method of pushing up and rolling up a protruding portion of a tire member with a bladder that is preliminarily charged on the inner peripheral surface side and expands in a balloon shape. As described above, the method of winding the tire member using the bladder is generally called a “bladder method”.

  Further, as shown in FIG. 15, Patent Documents 2 to 3 show that a tire member includes a plurality of rollers r spaced in the circumferential direction on the inner peripheral surface of the protruding portion c of the tire member along the main body g. A method of winding up the protruding portion c around the main body portion g by radially pushing up from the inside in the radial direction is disclosed. Such a winding method is generally called “mechanical method”.

JP 2003-39572 A JP 2004-268371 A JP 2004-9298 A

  The bladder system disclosed in Patent Document 1 requires maintenance such as periodically replacing the bladder. For this reason, there is a problem that the production line must be stopped every maintenance, and the productivity cannot be sufficiently improved.

  Further, in the mechanical systems of Patent Documents 2 to 3, the above-described bladder maintenance can be made unnecessary. However, as shown in FIG. 15, when the protruding portion c of the tire member is rolled up by the roller r, the side wall rubber c1 of the protruding portion c has a large pressure on the outer peripheral surface of the roller r and the arm f that supports the roller r. Touch and slide. As a result, as shown in FIG. 16 (a) and FIG. 16 (b), which is a cross-sectional view taken along the line AA, the outer surface of the bead portion or sidewall portion of the green tire t has a roller r and / or an arm f. There is a problem in that the groove-like recesses e recessed by are spaced apart. Such undulation is moderated to some extent by vulcanization, but depending on the situation, it may remain after vulcanization, and the appearance of the tire may be significantly deteriorated, and the weight unbalance may be caused to deteriorate uniformity. There is a problem.

  The present invention has been devised in view of the above situation, and the invention according to claim 1 is directed to incline the side region of the main body portion toward the radially outer side in the axial direction in the mechanical winding process. A bead hoisting stage for hoisting the bead part of the protruding part, and a side wall hoisting stage for raising the side part by raising the side wall part from the bead hoisting stage by reducing the axial distance between the bead cores. It is an object of the present invention to provide a method for manufacturing a pneumatic tire that can reduce undulation that tends to occur on the outer surface of a green tire without impairing productivity.

  Further, the invention according to claim 5 is based on the fact that the outer peripheral surface of the swing arm around which the tire member is wound is formed in an arc shape, so that the contact resistance with the tire member is reduced, and as a result tends to occur on the outer surface of the raw tire. It aims at providing the raw tire shaping | molding apparatus which can reduce an undulation.

  The invention according to claim 1 of the present invention includes a forming drum having a substantially cylindrical shape, and a tire member winding device disposed on both sides in the axial direction of the forming drum. A sliding member movable in the axial direction, and a plurality of swinging arms attached to the sliding member at intervals in the circumferential direction and extending in the axial direction. A method of manufacturing a pneumatic tire using a raw tire molding apparatus, wherein one end thereof is pivotally attached to the slide member and a roller is pivotally supported at the other end, the molding drum, A step of winding a tire member including a carcass ply in a cylindrical shape over a swing arm held along an axial direction, a step of fitting a pair of bead cores into the tire member, and a gap between the bead cores A step of expanding the ear member in a toroidal shape to form a main body portion, and moving the slide member in the axial direction toward the forming drum, thereby moving the rollers of the swing arms along the main body portion of the tire radius. And a winding step of winding the protruding portion of the tire member that is radially outward from the bead core to the main body portion, and the winding step includes a side region of the main body portion radially outward. A bead winding stage in which the bead portion of the protruding portion is wound inward in the axial direction toward the inner side, and an axial distance between the bead cores is shortened to raise the side region from the bead winding step to protrude the protruding portion. And a side wall winding step for winding the side wall portion.

  The invention according to claim 2 is the method for manufacturing a pneumatic tire according to claim 1, wherein, in the bead winding stage, an angle of inclination of the side region with respect to a tire axial direction is 10 to 50 degrees.

  The invention according to claim 3 is the method for producing a pneumatic tire according to claim 1 or 2, wherein an angle of inclination of the side region with respect to a tire axial direction is 60 to 80 degrees in the side wall winding stage.

  According to a fourth aspect of the present invention, in the cross-section perpendicular to the longitudinal direction of the swing arm, the outer peripheral surface in contact with the tire member has an arc shape. It is a manufacturing method of a entering tire.

  According to a fifth aspect of the present invention, there is provided a cylindrical molding drum around which a tire member including a carcass ply is wound, and a pair of bead cores arranged on both outer sides in the axial direction of the molding drum and extrapolated to the tire member A pair of axially movable bead core holding devices that hold the inner peripheral surface of the pair of bead core holding devices, and a protruding portion that is disposed on both outer sides of the pair of bead core holding devices and that is on the outer side in the tire axial direction than the bead core. A raw tire molding apparatus that includes a hoisting device that is wound and winds the protruding portion outward in the tire radial direction, the hoisting device being movable in the axial direction of the molding drum, and the slide member A plurality of oscillating arms attached at intervals in the circumferential direction and extending in the axial direction, the oscillating arms rising radially One end thereof is pivotally attached to the slide member, and a roller is pivotally supported at the other end. Further, the axial movement of the slide member causes the rollers of the swing arms to move along the main body. The tire member can be moved radially from the inside to the outside and the protruding portion of the tire member axially outside the bead core can be wound around the main body portion, and the swing arm has a cross section perpendicular to the longitudinal direction of the tire member. The outer peripheral surface which contacts is made into circular arc shape.

  In the invention described in claim 1, the winding process includes a bead winding stage and a sidewall winding stage. In the bead winding stage, the bead portion of the protruding portion is wound by tilting the side region of the main body portion inward in the radial direction toward the outside in the radial direction. In this way, by tilting the side region and winding up the protruding portion, the extension of the protruding portion is suppressed, and the contact pressure with the roller and the swing arm can be reduced as compared with the conventional case. Therefore, it is possible to effectively suppress the formation of a large undulation on the outer surface of the green tire.

  Further, in the sidewall winding stage, by narrowing the distance in the tire axial direction between the pair of bead cores, the side area of the main body is raised as compared with the bead winding stage, so that the protruding portion is wound up. As a result, the sidewall portion can be wound up without causing the swing arm to interfere with the bead portion that has already been wound up. In addition, since the side region has a so-called steep slope, the roller can be moved largely in the radial direction by the axial movement with few slide members. Therefore, productivity is improved. Note that, in the side wall winding stage, compared with the bead winding stage, a part of the winding is completed, so that the contact area between the swing arm and the protruding portion is reduced. For this reason, at the side wall winding stage, even if the side region is raised and rolled up as described above, there is little risk of undulation being formed.

  Further, in the invention according to claim 5, the oscillating arm has an arcuate outer peripheral surface around which the protruding portion is wound in a cross section perpendicular to the longitudinal direction thereof. Is unlikely to occur. Therefore, it is useful for manufacturing a pneumatic tire excellent in appearance and uniformity.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows a partial perspective view of a green tire molding apparatus 1 of the present embodiment, and FIGS. 2 and 3 show sectional views thereof. The green tire molding apparatus 1 includes a molding drum 2 having a substantially cylindrical shape, a pair of bead core holding devices 3 arranged on both outer sides in the axial direction of the molding drum 2, and both outer sides in the axial direction of the bead core holding device 3. And a hoisting device 4 for a tire member disposed in the vehicle. 1-3, although the whole is not shown in figure, the raw tire shaping | molding apparatus 1 of this embodiment has a left-right symmetric structure with respect to the reference line C (shown in FIG. 2).

  The molding drum 2 includes a center drum 2a disposed at the center thereof and a pair of side drums 2b, 2b disposed adjacent to both sides in the axial direction. Each of the drums 2a and 2b has substantially the same outer diameter and is coaxially disposed on the central shaft 5. Such a forming drum 2 provides a cylindrical outer peripheral surface having a wide width around which a tire member can be wound, by making the outer peripheral surfaces of the center drum 2a and the side drum 2b substantially continuous in the axial direction.

  In the center drum 2a, for example, an outer peripheral surface that is substantially continuous in the circumferential direction is formed by connecting a plurality of segments s in the circumferential direction, while the segments s are alternately and radially used by using the actuator 2a1. By pulling inward, the diameter can be reduced as shown in FIG.

  The side drum 2b includes a cylindrical base portion 2b1 and a sleeve 6 fixed to the outer edge in the tire axial direction via a flange 2b2, and the center drum 2a side is opened. The sleeve 6 is extrapolated to be movable with respect to the central shaft 5 and is connected to an actuator (not shown). Therefore, as shown in FIG. 3, the center drum 2 a can be reduced in diameter, and the pair of side drums 2 b and 2 b can be brought close to each other together with the sleeve 6.

  The bead core holding device 3 includes a ring-shaped inner base 3a fixed to the sleeve 6 in the vicinity of the flange 2b2 of the side drum 2b, and a ring fixed to the sleeve 6 at a position spaced axially outward from the inner base 3a. Between the inner base 3a and the outer base 3b, and a slide ring 3c disposed between the inner base 3a and the outer base 3b and movable in the axial direction along the sleeve 6; And a core receiving portion 3d that is held so as to be movable only in the direction and can be projected and retracted in the radial direction by sliding of the slide ring 3c.

  The core receiving portion 3d includes a plurality of segments divided in the circumferential direction, and in this embodiment, has a slope 3d1 that engages with the slope 3c1 of the slide ring 3c. The core receiving portion 3d can move radially outward by movement of the slide ring 3c in the axial direction, and can move radially inward by movement of the slide ring 3c in the axial direction. Here, the inside in the axial direction is a direction toward the reference line C, and the outside in the axial direction is a direction away from the reference line C.

  A rubber seat 3e is fixed to the outer surface of the core receiving portion 3d. One end of the rubber seat 3e in the axial direction is fixed to the inner base 3a, and the other end extends beyond the core receiving portion 3d in the axial direction so as to cover the outer base 3b in a cantilever manner.

  The hoisting device 4 includes a slide member 7 movable along the central axis 5 of the forming drum 2 and a plurality of swing arms attached to the slide member 7 at intervals in the circumferential direction and extending in the axial direction. 8 and so on.

  In the present embodiment, the slide member 7 has a ring shape that is extrapolated to the sleeve 6 and can move in the axial direction with respect to the sleeve 6 by a drive mechanism (not shown).

  The swing arm 8 is provided on the slide member 7 at a constant circumferential pitch, as is apparent from FIG. 4 which is an AA end view of FIGS. 1 and 3. The swing arm 8 is pivotally attached to the slide member 7 so that the arm 8 can be raised radially, and the other end 8b on the bead core holding device 3 side. A roller 9 is pivotally supported by the roller 9. The roller 9 can rotate around an axis along a tangential direction with respect to the circumference of the forming drum 2.

  The swing arm 8 is provided with an annular rubber band B for tightening them. Thereby, as shown in FIGS. 1 to 3, each swing arm 8 (and its outer peripheral surface) is maintained in an initial state of being substantially horizontal. At this time, in this embodiment, each roller 9 is placed on the horizontal outer surface of the outer base 3b as shown in FIGS. Further, as the slide member 7 moves inward in the axial direction, the swing arm 8 swings in a direction in which the roller 9 moves up the slope 3b1 provided on the outer base 3b while extending the rubber band B. On the other hand, by the movement of the slide member 7 in the axial direction outside, each swing arm 8 swings in the direction in which the roller 9 moves down the slope 3b1 by the tightening force of the rubber band B. In this initial state, a virtual cylinder (shown in FIG. 4) Vc connecting the outer peripheral surface 8c of the swing arm 8 is formed to be substantially equal to the outer diameter of the forming drum 2.

  A process of forming a raw tire using the raw tire forming apparatus 1 configured as described above will be described. First, as shown in FIG. 5, the tire member 10 is wound in a cylindrical shape across the forming drum 2 and the swing arm 8 held substantially along the axial direction. The tire member 10 includes, for example, an inner liner rubber 11, a bead rubber 14 connected to an edge in the width direction, a side wall rubber 13 connected to the bead rubber 14, and a carcass ply 12 wound around the outside. These may be integrated in advance or may be wound separately as in the present embodiment. At this time, the core receiving portion 3d of the bead core holding device 3 is slightly in the radial direction from the outer diameter of the forming drum 2 in consideration of, for example, the thickness of the bead rubber 14 and the subsequent fitting process of the bead core 15. It is desirable to wait at the inner position.

  Next, a step of fitting the pair of bead cores 15 into the tire member 10 from both outer sides in the axial direction is performed. The bead core 15 is fitted into a position corresponding to the core receiving portion 3 d of the bead core holding device 3. Thereafter, as shown in FIG. 6, the core receiving portion 3d is moved radially outward. Thereby, the core receiving part 3d can press and hold the inner peripheral surface of the bead core 15 via the rubber seat 3e and the tire member 10. The bead core 15 is preferably provided with a bead apex rubber 16 having a substantially crescent cross section, for example, in advance.

  Next, as shown in FIG. 7, a process of forming the main body portion 20 by inflating the tire member 10 between the bead cores 15 and 15 in a toroid shape is performed. That is, after the diameter of the center drum 2a of the forming drum 2 is reduced, the side drum 2b together with the sleeve 6 is moved inward in the axial direction to approach each other. Thereby, the bead core holding device 3 fixed to the sleeve 6 moves in the axial direction while holding the bead core 15, and the axial distance between the bead cores 15 and 15 can be reduced to CW1. At the same time, for example, by supplying high-pressure air or the like to the inner region i of the tire member 10, the tire member 10 between the bead cores 15 and 15 can be inflated and deformed in a toroid shape as shown in FIG. 7. At this time, the tread region of the tire member 10 is bonded to the inner peripheral surface of the ring-shaped tread rubber body 17 including the belt layer 17a and the tread rubber 17b waiting in advance in the radial direction.

  Next, in this embodiment, a trimming process is performed. In the trimming step, as shown in FIG. 8, the trim roller 19 having the same circumferential surface as the tire circumferential direction is pressed against the outer surface of the tread rubber body 17 to rotate the tire member, and the trim roller 19 is moved in the axial direction. This is done by moving slowly. As a result, the tread rubber body 17 is deformed and closely adhered along the outer surface of the tread region of the main body 20 shaped in a toroidal shape.

  After the trimming step, a winding step is performed in which the protruding portion 21 of the tire member protruding outward in the axial direction from the bead core 15 is wound up to the main body portion 20 side. The protruding portion 21 includes at least the carcass ply 12 and the sidewall rubber 13.

  The winding process of the present invention includes a bead winding stage of the protruding portion 21 and a side wall winding stage.

  The bead winding step is a step of winding the bead portion 21a of the protruding portion 21 around the main body portion 20, and prior to this, as shown in FIG. 9, the side region 20S of the main body portion 20 is directed radially outward. Tilted inward in the axial direction (tire equator side). Here, the side region 20S of the main body 20 is a region where the protruding portion 21 is rolled up and bonded.

  In the present embodiment, after the trimming step, the side drums 2b are separated from each other, thereby increasing the distance in the tire axial direction between the bead cores 15 and 15 from CW1 to CW2, thereby making the side region 20S more tire shafts. Tilt (lay down) in a direction approaching the direction and hold. In order to sufficiently attach the tread rubber body 17 to the main body portion 20, it is desirable that the distance CW1 at the trimming step is smaller than the distance CW2 at the bead winding stage.

  And after adjusting the side area | region 20S to the said inclination, as FIG. 10 shows, the slide member 7 of the winding apparatus 4 is moved to an axial direction inner side (forming drum 2 side). As a result, each roller 9 of the swing arm 8 moves radially so as to go up the slope 3b1 of the outer base 3b, winds up the bead portion 21a of the protruding portion 21 together with the rubber seat 3e, and the outer peripheral surface of the protruding portion 21. The surface that has been formed can be pressed against the main body 20 and pasted. While the roller 9 is moved outward in the radial direction, the protruding portion 21 is wound up toward the main body portion 20 while sliding on the outer peripheral surface 8 c of the swing arm 8.

  In such a bead winding stage, in the present embodiment, since the inclination of the side region 20S is set to be small with respect to the tire axial direction, distortion generated in the protruding portion 21 at the time of winding can be reduced. That is, as schematically shown in FIG. 11, when the side region 20S is wound up into the region OA of the length b with θa and θb (θa <θb) as the inclination angles with respect to the tire axial direction, the inclination angle Is smaller, the outer diameter of the circumferential line passing through the winding position A is also smaller (φa <φb). That is, by reducing the inclination angle θ of the side region 20S during winding, the radial extension of the protruding portion 21 can be reduced, and the contact pressure between the protruding portion 21 and the roller 9 or the protruding portion 21 and the swinging motion can be reduced. The sliding resistance with the outer peripheral surface 8c of the arm 8 can be reduced. Therefore, undulation and the like can be effectively suppressed from forming on the outer surface of the protruding portion 21.

  Here, in the bead winding stage, the inclination angle θ1 of the side region 20S of the main body 20 is not particularly limited, but is preferably 50 degrees or less, more preferably 45 degrees or less with respect to the tire axial direction. desirable. When the angle θ1 exceeds 50 degrees, the effect of suppressing distortion of the protruding portion 21 tends to decrease. On the other hand, if the angle θ1 is too small, the force of pressing the protruding portion 21 against the main body is insufficient, or the slide member 7 needs a large axial movement to complete the bead hoisting. There is a risk of interference between the swung arm 8 and the wound part. From such a viewpoint, the angle θ1 is preferably 10 degrees or more, more preferably 20 degrees or more, and further preferably 30 degrees or more.

  Here, as shown in FIG. 10, the inclination angle of the side region 20S is determined by the outer end point P1 in the tire radial direction of the side region 20S and the point P2 on the outermost side in the tire axial direction of the bead core 15 (the position is the tire radius). In the case of continuous in the direction, the point is the point on the outermost side in the tire radial direction.) The angle between the straight line L1 and the tire axial direction.

  On the other hand, as shown in FIG. 12, in the side wall winding stage in which the side wall portion 21b of the protruding portion 21 is wound up, the axial distance between the bead cores 15 and 15 is set to CW2 to CW3 by bringing the side drum 2b closer to each other. (<CW2), and the side region 20S is held in a state of being raised from the bead winding stage. Thus, the swing arm 8 and the like can be wound up to the outer end of the protruding portion 21 without causing interference with the bead portion of the side region 20S. Further, when the side region 20S of the main body 20 rises, the roller 9 can be moved greatly in the tire radial direction by a small axial movement of the slide member 7, and the remaining wide range can be wound up in a short time. Therefore, productivity deterioration can be prevented.

  Although not particularly limited, in the side wall winding stage, the inclination angle θ2 of the side region 20S is preferably 60 degrees or more, more preferably 70 degrees or more with respect to the tire axial direction. When the angle θ2 is less than 60 degrees, it takes time to wind up to the outer end of the protruding portion 21, and the swing arm 8 may interfere with the bead portion. On the other hand, if the angle θ2 is too large, the radial force that pushes the roller 9 outward in the radial direction may be reduced, and smooth winding may be difficult. From such a viewpoint, the angle θ2 is preferably 80 degrees or less, more preferably 75 degrees or less.

  Further, in order to further reduce the undulation of the outer surface of the raw tire, the swing arm 8 may have an arcuate outer peripheral surface 8c in a cross section perpendicular to the longitudinal direction, as shown in FIG. desirable. Such a swing arm 8 reduces resistance when sliding with the tire member 10, especially the sidewall rubber 13, during winding, and is effective in forming rubbing marks, dents and the like on the sidewall rubber 13. Can be suppressed. Here, the “arc-shaped” means that, as shown in FIG. 14 (a), the whole is formed by an arc having a single radius of curvature R1, and a parabola as shown in FIG. 14 (b). Further, as shown in FIG. 5C, a circular arc having a plurality of curvature radii R1 and R2 may be connected.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments illustrated, and it is needless to say that various modifications can be made without departing from the scope of the present invention.

  In order to confirm the effect of the present invention, 20 raw tires (tire size “215 / 60R16 95H”) were molded in accordance with the winding process specifications shown in Table 1, and the undulation shown in FIG. The recess depth d of the tire and the uniformity of the vulcanized tire were measured.

  The recess depth d was measured at three locations on the tire circumference at the bead portions on both sides of each green tire, and the total average value thereof was defined as the recess depth of the tire.

  Uniformity was measured for TFV and RFV according to JASO C607: 2000 uniformity test conditions using a cornering tester. The evaluation speed was 10 km / h. In each example, the average value (N) of 20 tires is calculated, and the result is expressed as an index with the value of the comparative example being 100. The larger the value, the better. The test results are shown in Table 1.

  As a result of the test, it was confirmed that the depth of the concave portion was significantly reduced in the raw tire of the example. Moreover, based on this, it has confirmed that the uniformity was also improved significantly compared with the comparative example.

It is a fragmentary perspective view of the raw tire shaping | molding apparatus of this embodiment. It is sectional drawing of the raw tire shaping | molding apparatus which shows embodiment of this invention. It is sectional drawing which shows the state which changed the shaping | molding drum. FIG. 3 is an AA end view of FIG. 2. It is sectional drawing which shows the state which wound the tire member around the raw tire shaping | molding apparatus. It is sectional drawing which shows the state which hold | maintained the bead core with the core receiving part of the bead core holding | maintenance apparatus. It is sectional drawing which shows the process of shape | molding a main-body part. It is sectional drawing which shows a trimming process. It is sectional drawing explaining a bead winding-up stage. It is sectional drawing explaining a bead winding-up stage. It is a schematic diagram explaining the effect | action of the inclination of the side area | region at the time of winding. It is sectional drawing explaining a sidewall winding-up stage. It is sectional drawing of a rocking | fluctuating arm. (A)-(c) is a fragmentary sectional view of a rocking | fluctuating arm. It is sectional drawing explaining the conventional winding process. (A) is a perspective view of a green tire, (b) is the AA sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Raw tire shaping | molding apparatus 2 Molding drum 3 Bead core holding | maintenance apparatus 4 Winding apparatus 7 Slide member 8 Oscillating arm 9 Roller 10 Tire member 12 Carcass ply 13 Side wall rubber 15 Bead core 20 Main body part 20S Side area 21 of main part Overhang part 21a Bead portion 21b Side wall portion of protruding portion t Raw tire

Claims (5)

A substantially cylindrical forming drum, and a tire member winding device disposed on both sides in the axial direction of the forming drum,
The hoisting device includes a slide member movable in the axial direction of the forming drum, and a plurality of swing arms attached to the slide member at intervals in the circumferential direction and extending in the axial direction. The swing arm is a method of manufacturing a pneumatic tire using a raw tire molding device in which one end is pivotally attached to the slide member and a roller is pivotally supported at the other end so that the swing arm can rise radially. There,
Winding the tire member including the carcass ply in a cylindrical shape across the forming drum and the swing arm held along the axial direction;
Inserting a pair of bead cores into the tire member;
A step of inflating a tire member between the bead cores in a toroidal shape to form a main body part; and
By moving the slide member in the axial direction toward the forming drum, the rollers of the swing arms are moved radially inward from the radial direction of the tire along the main body portion, and are axially outside the bead core. A winding step of winding the protruding portion of the tire member around the main body portion,
The winding step includes a bead winding step of winding the bead portion of the protruding portion by inclining the side region of the main body portion in the axial direction toward the radially outer side,
A pneumatic tire comprising: a side wall hoisting step of raising the side region from the bead hoisting step to wind up a side wall portion of the protruding portion by reducing an axial distance between the bead cores. Production method.   The method for manufacturing a pneumatic tire according to claim 1, wherein, in the bead winding stage, an inclination angle of the side region with respect to a tire axial direction is 10 to 50 degrees.   The method for manufacturing a pneumatic tire according to claim 1 or 2, wherein, in the side wall winding stage, an angle of inclination of the side region with respect to a tire axial direction is 60 to 80 degrees.   The method for manufacturing a pneumatic tire according to any one of claims 1 to 3, wherein an outer peripheral surface of the swing arm in contact with the tire member has an arc shape in a cross section perpendicular to a longitudinal direction thereof. A cylindrical molding drum around which a tire member including a carcass ply is wound;
A pair of bead core holding devices which are arranged on both outer sides in the axial direction of the forming drum and which are movable in the axial direction to hold the inner peripheral surfaces of the pair of bead cores inserted through the tire member via the tire member;
A raw tire molding device including a hoisting device that is disposed on both outer sides of the pair of bead core holding devices and is wound around a protruding portion outside the bead core in the tire axial direction and winds the protruding portion outward in the tire radial direction. There,
The winding device includes a slide member that is movable in the axial direction of the forming drum, and a plurality of swing arms that are attached to the slide member at intervals in the circumferential direction and extend in the axial direction.
One end of the swing arm is pivotally attached to the slide member so that it can rise radially, and a roller is pivotally supported at the other end.
In addition, the axial movement of the slide member causes the rollers of the swing arms to move radially inward from the tire radial direction along the main body portion, so that the protruding portion of the tire member axially outside the bead core is the main body portion. And roll up
The swinging arm is a green tire molding apparatus characterized in that an outer peripheral surface in contact with the tire member forms an arc shape in a cross section perpendicular to the longitudinal direction of the swing arm.

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