JP2010058270A - Method and apparatus for producing green tire - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To effectively suppress the occurrence of wrinkles by making the amplitude and wavelength of waving generated in the outside part 17b in the axial direction of a tire intermediate band 17 approximately uniform in the circumference. <P>SOLUTION: Since after the outside part 17b in the axial direction of the tire intermediate band 17 is held between oscillating vanes 32 and 33 and holding rods 40 and 41, the oscillating vanes 32 and 33 are oscillated radially inside with the holding rods 40 and 41, and the diameter of the outside part 17b in the axial direction is contracted, a part circumferential held between the oscillating vanes 32 and 33 and the holding rods 40 and 41 is restricted strongly, can not wave radially inside, and becomes a waving crest. The waving crest is of the same number as the holding rods 40 and 41 and positioned at an equal angle away, and the amplitude and wavelength are made approximately uniform. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

    The present invention relates to a green tire manufacturing method and apparatus for manufacturing a green tire by reducing a diameter of an axially outer side portion of a tire intermediate band and then setting a bead core on a stepped portion.

As a conventional green tire manufacturing method and apparatus, for example, those described in Patent Document 1 below are known.
JP 2000-202923 A

  In this, first, the central part of the cylindrical tire intermediate band in the axial direction is supported from the inside in the radial direction by the tire forming drum, and then the tire forming drum is axially spaced from the outer side in the circumferential direction by equiangularly away from each other. The plurality of swinging blades extending substantially in the axial direction are brought into contact with the outer surface of the outer side in the axial direction of the tire intermediate band located on the outer side in the axial direction from the outer end in the axial direction of the tire forming drum. Is synchronously rocked radially inward with the axially outer end as a center, and the axially outer side portion of the tire intermediate band is reduced to a diameter smaller than the inner diameter of the bead core, and then the intermediate diameter of the tire is reduced by the reduced diameter. A bead core is supplied and set to the step part formed in the band.

    However, in such a conventional green tire manufacturing method and apparatus, the axially outer portion of the intermediate band of the tire is reduced in diameter to be smaller than the inner diameter of the bead core by swinging the swing blade inward in the radial direction. Therefore, there is a surplus of the circumferential length (the length obtained by subtracting the circumferential length after the diameter reduction from the original circumferential length) on the outer side in the axial direction of the tire intermediate band, and this remainder is the radius in the circumferential direction. It will be a wave of direction.

  Here, the undulation as described above becomes larger as the circumferential bending stiffness is smaller, but the circumferential bending stiffness of the tire intermediate band varies to some extent when viewed in the circumferential direction. There is a problem that it becomes non-uniform in the circumferential direction. And since the site | part with a large amplitude of a wavy will be wrinkled in a post process, correction work is needed, As a result, there also exists a subject that work efficiency will fall.

  The present invention provides a method and an apparatus for manufacturing a green tire in which the amplitude and wavelength of undulations generated on the outer side in the axial direction of a tire intermediate band are made substantially uniform in the circumferential direction and wrinkles can be effectively suppressed. For the purpose.

    The purpose of this is to firstly support the axial central portion of the cylindrical tire intermediate band from the inside in the radial direction by the tire forming drum, and equiangularly in the circumferential direction on both axial outer sides of the tire forming drum. A plurality of oscillating blades extending substantially in the axial direction, which are spaced apart from each other, are brought into contact with the outer surface of the outer side in the axial direction of the tire intermediate band located on the outer side in the axial direction from the outer end in the axial direction of the tire forming drum and oscillated. The holding members, which are arranged at equal angles in the circumferential direction on the radially inner side of the blades and whose number is 1/2 or more of the swing blades, are brought into contact with the inner surface of the outer side in the axial direction of the tire intermediate band. The step of holding the outer side portion of the tire intermediate band in the axial direction by the holding member, and the swinging blade is swung synchronously inward in the radial direction together with the holding member around the outer end portion in the axial direction. wing A step of reducing the axially outer side portion of the tire intermediate band sandwiched between the root and the pinching member until the inner diameter of the bead core is smaller than the inner diameter of the bead core, and supplying the bead core to the stepped portion formed in the tire intermediate band by the reduced diameter. This can be achieved by a green tire manufacturing method including a step of setting and a step of turning a tire intermediate band outside in the axial direction from the bead core around the bead core.

  Second, a tire molding drum that supports the central portion in the axial direction of the cylindrical tire intermediate band from the inside, and an axially opposite outer side of the tire molding drum that are arranged at equal angular intervals in the circumferential direction. A plurality of oscillating blades that extend and contact the outer surface of the tire intermediate band in the axial direction outside the axially outer end of the tire forming drum; Are disposed at an equal angle in the direction, and the number of the sandwiching members is 1/2 or more of the swing blades, and the swing blades are in contact with the outer surface of the tire intermediate band in the axial direction. By contacting the inner surface of the outer side in the axial direction, the outer side in the axial direction of the tire intermediate band sandwiched between the swinging blade and the sandwiching member can be moved in the radial direction together with the sandwiching member with the swinging blade at the outer end in the axial direction. A diameter reducing means for reducing the diameter until the inner diameter of the bead core is smaller than the inner diameter of the bead core, and a bead supply means for supplying and setting the bead core to the stepped portion formed in the tire intermediate band by the reduced diameter; This can be achieved by a green tire manufacturing apparatus provided with a turning means for turning back a tire intermediate band axially outside the bead core around the bead core.

  In this invention, after the swinging blade and the clamping member are brought into contact with the outer surface and the inner surface of the tire intermediate band in the axial direction, the axially outer portion of the tire intermediate band is clamped by the swinging blade and the clamping member. Since the swinging blade is synchronously rocked radially inward with the pinching member, the outer diameter portion of the tire intermediate band sandwiched from both sides is reduced in diameter as described above. The circumferential portion sandwiched between the two is strongly constrained and cannot undulate inward in the radial direction, and becomes the top of the undulating mountain. Here, the sandwiching members are arranged at equal angular intervals in the circumferential direction, and the number thereof is 1/2 or more of the swinging blades, so that the top of the undulating mountain is also 1/2 or more of the swinging blades. Are located at an equal angle in the circumferential direction.

  As a result, the amplitude and wavelength of the undulation generated at the axially outer side portion of the tire intermediate band become substantially uniform in the circumferential direction, and as a result, the quality of the product tire is improved. Moreover, since the axially outer portion of the tire intermediate band undulates with substantially the same amplitude in the circumferential direction, it is possible to effectively suppress the generation of wrinkles in the subsequent process, and as a result, no correction work is required. Efficiency is improved.

  Further, when configured as described in claim 2, the order of undulation (number of undulations per round) can be increased, and as a result, the amplitude and wavelength of each undulation are reduced and the uniformity is improved. To do. Furthermore, if it comprises as described in Claim 3, the contact area of a tire intermediate band and a clamping member will become narrow, and the frictional resistance between the tire intermediate band and a clamping member at the time of diameter reduction will become small, and a tire Application of an extra external force to the intermediate band can be suppressed. Further, if the tire intermediate band is formed with a separate drum as described in claim 4, the forming operation is easy and the efficiency becomes high.

Embodiment 1 of the present invention will be described below with reference to the drawings.
1 and 2, 11 is a tire forming drum connected to a drive unit (not shown) via a main shaft 12 and a link mechanism to be described later. The tire forming drum 11 receives a driving rotational force from the drive unit. It can be driven to rotate around a horizontal axis. The tire molding drum 11 is composed of a plurality of arc segments 13, and these arc segments 13 are arranged equidistantly in the circumferential direction.

  14 is a link mechanism as an expansion / contraction mechanism provided between the arc segment 13 and the main shaft 12, and when a driving force is applied to the link mechanism 14 from the drive unit, the arc segment 13 moves synchronously in the radial direction. Then, the tire forming drum 11 expands and contracts. When the arc segment 13 moves to the outer limit in the radial direction, a tire molding drum 11 having a cylindrical shape in an expanded state is molded from the arc segment 13. In the present invention, a cylinder, a conical cam or the like may be used as the expansion / contraction mechanism.

  Reference numeral 17 denotes a cylindrical tire intermediate band fitted to the outside of the tire forming drum 11. The tire intermediate band 17 is formed by a band forming drum (not shown), and is then tired by a conveying device (not shown). It is carried into the molding drum 11, and then the tire molding drum 11 is supported by the tire molding drum 11 from the inside in the radial direction by expanding the diameter. Here, since the axial length of the tire intermediate band 17 is longer than the axial length of the tire molding drum 11, the axial middle portion 17a of the tire intermediate band 17 is supported by the tire molding drum 11 from the radially inner side. On the other hand, both axially outer portions 17b protrude outward in the axial direction from both axial ends of the tire forming drum 11.

  In this way, after the cylindrical tire intermediate band 17 is formed around the band forming drum which is a drum different from the tire forming drum 11, the tire intermediate band 17 is transferred from the band forming drum to the tire forming drum 11. Thus, if it is supported by the tire molding drum 11, it is possible to perform the operation simultaneously with both drums, which facilitates the molding operation and makes the operation highly efficient. Here, the tire intermediate band 17 described above is formed by winding tire constituent members such as an inner liner, a rubber chafer, a hat rubber, a wire chafer, a carcass ply, etc. around the band forming drum one after another.

  30 and 31 are movable bodies arranged on both outer sides in the axial direction of the tire forming drum 11 and having a cylindrical shape coaxial with the main shaft 12. These movable bodies 30 and 31 receive a driving force from a driving mechanism (not shown). Thus, it can move in the axial direction of the main shaft 12 and can approach and separate from the tire forming drum 11. Axial outer ends (base ends) of a plurality of (usually about 8 to 18) swinging blades 32 and 33 extending substantially in the axial direction can be rotated at the inner ends of the movable bodies 30 and 31. As a result, the swinging blades 32 and 33 are respectively arranged on both outer sides in the axial direction of the tire forming drum 11 and can swing in the radial direction with the outer end in the axial direction as a swing center.

  Further, the swing blades 32 and 33 are disposed at an equal angle in the circumferential direction, and the cross-sectional shape is arcuate, and the tire intermediate band 17 is located on the outer side in the axial direction from the outer end in the axial direction of the tire forming drum 11. It can contact the outer surface of the axially outer portion 17b. Here, the oscillating blades 32 and 33 are biased so as to be opened by a torsion spring (not shown), that is, to oscillate outward in the radial direction. Swinging outward in the direction is restricted by a stopper (not shown) so as to stop at the outer rocking limit that is a predetermined angle away from the axial direction.

  36 and 37 are substantially cylindrical holders whose inner diameters are slightly larger than the outer diameters of the axially outer ends of the swing blades 32 and 33, and these holders 36 and 37 are coaxial with the main shaft 12. Thus, it can move in the axial direction separately from the movable bodies 30 and 31 by a driving force from a driving mechanism (not shown), and can approach and separate from the tire forming drum 11. 26 and 27 are loosely fitted in the movable bodies 30 and 31, and are support bodies coaxial with the holding bodies 36 and 37. These support bodies 26 and 27 are connected to the holding bodies 36 and 37, and the holding bodies 36 and 37 It can move in the axial direction integrally with 37.

  28 and 29 are a pair of folded bladders that are locked in an airtight state at both ends to the outer periphery of each support 26 and 27, and these folded bladders 28 and 29 are usually contracted to have a cylindrical shape, When a high-pressure fluid is supplied to the inside, it expands in a substantially donut shape. The holding bodies 36 and 37 have can portions 36a and 37a at their inner ends in the axial direction, and these can portions 36a and 37a face the folded bladders 28 and 29 expanded in the axial direction as described above. Can be pushed down.

  The swinging blades 32 and 33 are positioned at the outer swing limit, and the axial inner ends (tips) of the swinging blades 32 and 33 are positioned slightly outside the axially outer ends of the tire forming drum 11 in the axial direction. When the movable bodies 30 and 31 are positioned at the inner limit, when the holding bodies 36 and 37 move toward the inner side in the axial direction, the inner peripheral surface of the inner end portion in the axial direction of the holding bodies 36 and 37 becomes the swing blade 32, The oscillating blades 32 and 33 are slidably contacted with the outer peripheral surface of 33 and synchronously oscillated inward in the radial direction around the outer end in the axial direction. As a result, the oscillating blades 32 and 33 are in contact with the outer surface of the axially outer portion 17b of the tire intermediate band 17. In the present invention, the stopper for defining the swinging blades 32, 33 to the outer swing limit is omitted, while the swinging blades 32, 33 are pressed by the holding bodies 36, 37, so that the swinging blade 32, 33 may be defined as the outer swing limit.

  Reference numerals 40 and 41 denote sandwiching rods having a circular cross section as a sandwiching member that is disposed radially equidistantly in the circumferential direction of the oscillating blades 32 and 33 and extends linearly in the substantially axial direction. These sandwiching rods 40 and 41 Is more than half of the oscillating blades 32, 33, and here is the same number as the oscillating blades 32, 33. The axially outer ends (base ends) of the sandwiching rods 40 and 41 are rotatably connected to the proximal ends of the swinging blades 32 and 33. As a result, the sandwiching rods 40 and 41 swing the proximal ends. It can swing as a moving center.

  42 and 43 are a pair of cylindrical movable cylinders, and these movable cylinders 42 and 43 are slidably fitted to the inner peripheral surfaces of the movable bodies 30 and 31, and in the axial direction of the tire forming drum 11. Can move. Ring-shaped cylinder chambers 46 and 47 are defined by annular grooves 44 and 45 between the movable cylinders 42 and 43 and the movable bodies 30 and 31. 51 and 52 are stored in the cylinder chambers 46 and 47, respectively, and are a pair of fixed pistons having a ring shape fixed to the inner peripheral surfaces of the movable bodies 30 and 31, and these fixed pistons 51 and 52 serve as cylinder chambers. 46 and 47 are divided into inner chambers 46a and 47a and outer chambers 46b and 47b.

  Reference numerals 53 and 54 denote a plurality of transmission links (the same number as the sandwiching rods 40 and 41). The base ends of the transmission links 53 and 54 are rotatably connected to the inner ends of the movable cylinders 42 and 43. Reference numerals 57 and 58 denote a plurality of connecting arms whose base ends are fixed to the outer ends in the axial direction of the sandwiching rods 40 and 41. The tips of these connecting arms 57 and 58 rotate to the tips of the transmission links 53 and 54, respectively. Connected as possible. As a result, when high pressure fluid, here, air of constant pressure is supplied to the inner chambers 46a and 47a of the cylinder chambers 46 and 47, the sandwiching rods 40 and 41 are synchronously rocked radially outward and the shaft of the tire intermediate band 17 is rotated. It contacts the inner surface of the direction outer side portion 17b.

  On the other hand, when high-pressure fluid is supplied to the outer chambers 46b and 47b of the cylinder chambers 46 and 47, the sandwiching rods 40 and 41 swing synchronously radially inward to the inner swing limit. The aforementioned movable cylinders 42 and 43, cylinder chambers 46 and 47, transmission links 53 and 54, and connecting arms 57 and 58 as a whole swing the clamping rods 40 and 41 radially outward about their axial outer ends. Thus, the swing mechanism 59 is configured to contact the inner surface of the tire intermediate band 17 in the axially outer side portion 17b.

  As described above, when the swinging blades 32 and 33 are synchronously rocked radially inward and the sandwiching rods 40 and 41 are synchronously rocked radially outward, the swinging blades 32 and 33 are axially outer. The sandwiching rods 40 and 41 are in contact with the inner surface of the axially outer portion 17b on the outer surface of the portion 17b, and thereby the swinging blades 32 and 33 and the sandwiching rod are swung until the axially outer portion 17b is substantially parallel. 40 and 41 are sandwiched from both sides.

  In the above-described embodiment, the swinging blades 32 and 33 are swung inward in the radial direction and the sandwiching rods 40 and 41 are swung out in the radial direction at the same time. 33, the axially outer portion 17b is clamped by the clamping rods 40, 41. In the present invention, after the oscillating blades 32, 33 are oscillated, the clamping rods 40, 41 are oscillated. Alternatively, after the sandwiching rods 40 and 41 are swung, the swinging blades 32 and 33 are swung so that the axially outer portion 17b is sandwiched by the swinging blades 32 and 33 and the sandwiching rods 40 and 41. It may be.

  Moreover, in this invention, it is good also as rocking | fluctuating this clamping member by connecting the base end of the said clamping member to a movable body so that rotation is possible. Furthermore, in the present invention, a pinching member extending in parallel to the swinging blade is disposed on the radially inner side of the swinging blade, and these pinching members are translated by a cylinder, a link mechanism, etc. The both sides in the direction may be clamped in cooperation with the swing blade.

  Next, when the holding bodies 36 and 37 are further moved inward in the axial direction in the above-described state, the swinging blades 32 and 33 are further swung inward in the radial direction, whereby the swinging blades 32 and 33 are sandwiched. The rods 40 and 41 are reduced in diameter until they are slightly smaller in diameter than a bead core 66 described later while sandwiching the axially outer portion 17b. At this time, a stepped portion 17c that is bent along both axial end surfaces of the tire molding drum 11 is formed at the boundary between the axial center portion 17a and the axial outer portion 17b of the tire intermediate band 17. Note that the clamping force at this time is constant regardless of the swinging position because air of a constant pressure is supplied to the inner chambers 46a and 47a.

  As a whole, the holding bodies 36 and 37 and the swinging mechanism 59 described above have the swinging blades 32 and 33 in contact with the outer surface of the axially outer portion 17b of the tire intermediate band 17 and the sandwiching rods 40 and 41 of the tire intermediate band 17. By contacting the inner surface of the axially outer portion 17b, the axially outer portion 17b of the tire intermediate band 17 sandwiched between the swinging blades 32 and 33 and the sandwiching rods 40 and 41 is connected to the swinging blades 32 and 33 in the axial direction. The diameter reducing means 60 is configured to reduce the diameter of the bead core 66 to be smaller than the inner diameter of the bead core 66 by swinging in the radial direction together with the sandwiching rods 40 and 41 around the outer end.

  In this way, the swinging blades 32 and 33 and the sandwiching rods 40 and 41 are brought into contact with the outer surface and the inner surface of the tire intermediate band 17 in the axial direction, respectively. After pinching the outer portion 17b in the direction, the swinging blades 32 and 33 are synchronously swung with the sandwiching rods 40 and 41 radially inward to reduce the diameter of the axially outer portion 17b sandwiched from both sides. The circumferential portion of the axially outer portion 17b sandwiched between the oscillating blades 32 and 33 and the sandwiching rods 40 and 41 is strongly constrained and cannot undulate radially inward, and becomes the top of the undulating mountain. .

  Here, the sandwiching rods 40 and 41 are arranged at equal angular intervals in the circumferential direction, and the number thereof is more than 1/2 of the swinging blades 32 and 33, so that the top of the undulating mountain also swings. While the number of blades 32 and 33 is more than half the number, they are located at an equal angle in the circumferential direction. As a result, the amplitude and wavelength of the undulation generated in the axially outer side portion 17b of the tire intermediate band 17 become substantially uniform in the circumferential direction, and the quality of the product tire is improved. Moreover, since the axially outer portion 17b of the tire intermediate band 17 undulates with substantially the same amplitude in the circumferential direction, it is possible to effectively suppress the generation of wrinkles in the subsequent process, and as a result, no correction work is required. Work efficiency.

  When the number of the oscillating blades 32 and 33 is N, it is preferable that the number of the sandwiching rods 40 and 41 is a number obtained by multiplying N by a natural number (excluding zero). The value is multiplied. The reason is that the order of undulation (the number of undulations per round) is determined by the number of sandwiching rods 40 and 41, so that the order of undulation can be easily increased. This is because the wavelength is reduced and the uniformity can be improved with certainty.

  Here, the sandwiching rods 40 and 41 may be constituted by strips having a circular arc cross section. However, if the sandwiching rods 40 and 41 are constituted by rods extending in a straight line having a circular cross section as in this embodiment, the tire intermediate band 17 (axial direction) The contact area between the outer side portion 17b) and the sandwiching rods 40, 41 is narrowed, and the frictional resistance between the tire intermediate band 17 and the sandwiching rods 40, 41 when the diameter is reduced is reduced. Since application of external force can be suppressed, it is preferable. Reference numerals 63 and 64 denote permanent magnets as ring-shaped adsorbers that are fixed to the radially inner end portions of the can portions 36a and 37a in the axial direction, and these permanent magnets 63 and 64 are substantially bowl-shaped. It is possible to adsorb and hold a bead core 66 having a circular, square or hexagonal cross section made of steel to which a filler 65 made of unvulcanized rubber is attached.

  When the holding bodies 36 and 37 are moved further inward in the axial direction after the diameter reduction of the axially outer portion 17b, the bead core 66 with the filler 65 held by the permanent magnets 63 and 64 is pressed against the stepped portion 17c. Then, the bead core 66 is supplied to and set at a predetermined position outside the both ends in the axial direction of the tire intermediate band 17, here, the stepped portion 17c. The holding bodies 36 and 37 having the can portions 36a and 37a, the permanent magnets 63 and 64, and the drive mechanism as a whole are set by supplying the bead core 66 to the stepped portion 17c formed in the tire intermediate band 17 by the reduced diameter. The bead supply means 67 is configured.

  As described above, when the bead core 66 is set in the stepped portion 17c, the sandwiching rods 40 and 41 are synchronously swung inward in the radial direction and separated from the axially outer portion 17b, and the movable bodies 30 and 31 are held. The bodies 36 and 37 move outward in the axial direction, and a predetermined gap is formed between the axial ends of the tire forming drum 11 and the swinging blades 32 and 33, the holding bodies 36 and 37, and the sandwiching rods 40 and 41.

  When the gap is formed in this way, the folding bladders 28 and 29 of the supports 26 and 27 moved inward in the axial direction together with the holding bodies 36 and 37 expand in a substantially donut shape in the gap. At this time, the holding body 36 and 37 move inward in the axial direction to push down the folding bladders 28 and 29 toward the inner side in the axial direction, so that the tire intermediate band 17 outside the bead core 66 in the axial direction is placed around the bead core 66 as shown in FIG. Turn back.

  The above-described supports 26, 27, folding bladders 28, 29, and holding bodies 36, 37 constitute folding means 70 that folds the tire intermediate band 17 axially outside the bead core 66 around the bead core 66. Here, the holding bodies 36 and 37 are shared by the diameter reducing means 60, the bead supply means 67, and the folding means 70 as described above. As a result, the structure becomes simple and can be manufactured at low cost.

  Thereafter, the holding bodies 36 and 37 are moved outward in the axial direction, but the movement of the holding bodies 36 and 37 is stopped when the permanent magnets 63 and 64 reach slightly inward in the axial direction from the tips of the swinging blades 32 and 33. . Next, a tire constituent member, here, a side tread is supplied and wound around the outer ends of both ends in the axial direction of the tire intermediate band 17 while the tire molding drum 11 is rotated. As a result, the green case 73 is molded outside the tire molding drum 11.

  Next, the green case 73 is conveyed from the tire forming drum 11 to the shaping drum 75 as shown in FIG. 4 by a conveying device (not shown) and fitted to the outside of the shaping drum 75. Here, the above-described shaping drum 75 is supported by a main shaft 76 that can receive a driving force from a driving unit (not shown) and rotate around the axis, and can be expanded and contracted on the main shaft 76 and can be moved in the axial direction. When the green case 73 is carried into the shaping drum 75 as described above, the pair of bead lock bodies 77 expands in diameter, and the bead core 66 of the green case 73 is moved in the radial direction. Support each from the inside.

  Next, while moving the bead lock body 77 inward in the axial direction, air of an internal pressure, for example, low pressure, is supplied into the green case 73 between the bead cores 66 to bulge the axially central portion of the green case 73 outward in the radial direction. . At this time, a cylindrical belt tread band 80 formed by successively winding a belt 78, a top tread 79, etc. around a band drum (not shown) is formed on the outside of the green case 73 in the radial direction by the conveying device 81. And is affixed to the green case 73. Thereafter, the belt tread band 80 is pressure-bonded to the green case 73 by a stitching device (not shown) to form a green tire.

Next, the operation of the first embodiment of the present invention will be described.
When manufacturing a green tire using the manufacturing apparatus as described above, first, the bead core 66 with filler 65 is supplied to the holding bodies 36 and 37 waiting at the standby position by a bead supply means (not shown), It passes to the permanent magnets 63 and 64 of the holders 36 and 37. At this time, since the tire molding drum 11 is in a reduced diameter state, the bead core 66 is transferred to the permanent magnets 63 and 64 without interfering with the tire molding drum 11.

  Next, the cylindrical tire intermediate band 17 formed by the band forming drum is carried into the tire forming drum 11 by the transport device and fitted to the outside thereof. Next, when a driving force is applied from the driving unit to the link mechanism 14 to move the arcuate segment 13 synchronously outward in the radial direction, the tire forming drum 11 is expanded in diameter. As a result, the tire forming drum 11 supports the central portion 17a in the axial direction of the tire intermediate band 17 from the inside. At this time, both the axially outer portions 17b protrude axially outward from both axial ends of the tire forming drum 11, There is no support by the tire forming drum 11.

  Next, the movable bodies 30 and 31 are moved inward in the axial direction to the inner limit, and the swinging blades 32 and 33 and the sandwiching rods 40 and 41 are brought close to the tire forming drum 11. At this time, the swinging blades 32 and 33 swing and stop radially outward to the outer swing limit by the stopper, while the clamping rods 40 and 41 swing and stop radially inward to the inner swing limit. Therefore, both the axially outer side portions 17b are respectively positioned at substantially intermediate positions between the swinging blades 32 and 33 and the sandwiching rods 40 and 41 that are separated in the radial direction.

  Next, the holding bodies 36 and 37 are moved inward in the axial direction together with the support bodies 26 and 27. At this time, the inner peripheral surface of the inner end portion in the axial direction of the holding bodies 36 and 37 becomes the outer peripheral surface of the swinging blades 32 and 33. The oscillating blades 32 and 33 are in sliding contact with each other and oscillate synchronously inward in the radial direction with the axially outer end as a center. At the same time, when high pressure fluid is supplied to the inner chambers 46a and 47a of the cylinder chambers 46 and 47 to move the movable cylinders 42 and 43 inward in the axial direction, the movement of the movable cylinders 42 and 43 is transferred to the transmission links 53 and 54. Then, it is transmitted to the sandwiching rods 40 and 41 via the connecting arms 57 and 58, and the sandwiching rods 40 and 41 are synchronously oscillated radially outward about the outer end in the axial direction.

  As a result, the swinging blades 32 and 33 come into contact with the outer surface of the axially outer portion 17b, while the sandwiching rods 40 and 41 come into contact with the inner surface of the axially outer portion 17b. It is clamped from both sides by the swinging blades 32 and 33 and the sandwiching rods 40 and 41 swinging until they become parallel. Thereafter, when the holding bodies 36 and 37 are moved inward in the axial direction, the swinging blades 32 and 33 further swing inward in the radial direction together with the sandwiching rods 40 and 41. At this time, since the movable cylinders 42 and 43 are supplied with constant pressure air to the inner chambers 46a and 47a, the movable cylinders 42 and 43 move in the axial direction following the swinging of the sandwiching rods 40 and 41. It does not affect the swing.

  By swinging inward in the radial direction as described above, the swinging blades 32 and 33 and the sandwiching rods 40 and 41 are squeezed by pushing inward in the radial direction while sandwiching the axially outer portion 17b of the tire intermediate band 17 from both sides, The axially outer portion 17b is reduced in diameter until it becomes slightly smaller than the bead core 66 while maintaining a substantially cylindrical shape. At this time, a stepped portion 17c that is bent along both axial end surfaces of the tire molding drum 11 is formed at the boundary between the axial center portion 17a and the axial outer portion 17b of the tire intermediate band 17.

  In this way, the diameter of the axially outer portion 17b is reduced while being clamped from both sides by the swinging blades 32 and 33 and the sandwiching rods 40 and 41, so the sandwiching between the swinging blades 32 and 33 and the sandwiching rods 40 and 41 is performed. The circumferential portion of the axially outer portion 17b is strongly constrained and cannot undulate inward in the radial direction, and becomes the top of a undulating mountain. Here, the sandwiching rods 40 and 41 are arranged at equal angular intervals in the circumferential direction, and the number thereof is more than 1/2 of the swinging blades 32 and 33, so that the top of the undulating mountain also swings. While the number of blades 32 and 33 is equal to or more than 1/2 of the blades 32 and 33, they are located at an equal angle in the circumferential direction, and the amplitude and wavelength of the undulation generated in the axially outer portion 17b are substantially uniform in the circumferential direction. The correction work is also unnecessary. Here, since the waviness described above becomes more prominent as the tire diameter increases, this embodiment is suitable for a super-large tire to be mounted on a large construction vehicle.

  After the diameter reduction of the axially outer portion 17b described above, the holders 36 and 37 are further moved inward in the axial direction, and the bead core 66 with the filler 65 held by the permanent magnets 63 and 64 is moved to the stepped portion 17c. Press and pass to the tire intermediate band 17. As a result, the bead core 66 is supplied and set to a predetermined position outside the both ends of the tire intermediate band 17 in the axial direction, here, the stepped portion 17c.

  Next, high-pressure fluid is supplied to the outer chambers 46b and 47b of the cylinder chambers 46 and 47, the movable cylinders 42 and 43 are moved outward in the axial direction, and the sandwiching rods 40 and 41 are swung to the inner swing limit. Thereafter, the movable bodies 30, 31, the holding bodies 36, 37 are moved outward in the axial direction by the same distance, both ends of the tire forming drum 11 in the axial direction and the swinging blades 32, 33, the holding bodies 36, 37, the sandwiching rod 40, A predetermined gap is formed with 41. At this time, in the tire forming drum 11 of this embodiment, since the folding bladder is not always located on both outer sides in the axial direction of the forming drum as in the prior art, the sandwiching rods 40 and 41 can be pulled out outward in the axial direction without any problem. it can.

  Next, a high-pressure fluid is supplied into the folded bladders 28 and 29 of the supports 26 and 27 stopped at the above-mentioned positions together with the holding bodies 36 and 37, and the folded bladders 28 and 29 are formed in a substantially donut shape in the gap. Inflate. Next, the holding bodies 36 and 37 are moved inward in the axial direction integrally with the support bodies 26 and 27, and the folding bladders 28 and 29 are pushed down toward the inner side in the axial direction by the holding bodies 36 and 37. The tire intermediate band 17 on the axially outer side from 66 is folded back around the bead core 66, and then the folded bladders 28 and 29 are contracted.

  Next, after the holding bodies 36 and 37 are moved outward in the axial direction together with the supports 26 and 27, side treads are supplied to the outside of both ends in the axial direction of the tire intermediate band 17 while the tire forming drum 11 is rotated by the drive unit. Then, the green case 73 is formed on the outside of the tire forming drum 11. Next, after the green case 73 is gripped from the outside by the conveying device, the diameter of the tire forming drum 11 is reduced, and the green case 73 is transferred from the tire forming drum 11 to the conveying device. Next, the green case 73 is conveyed to the shaping drum 75 by the conveying device and transferred to the shaping drum 75, and the bead lock body 77 is expanded in diameter, and the bead core 66 of the green case 73 is supported from the radially inner side.

  Next, the bead lock body 77 is moved inward in the axial direction to bring both ends of the green case 73 in the axial direction, that is, the bead cores 66 close to each other. At this time, internal pressure is supplied into the green case 73 between the bead cores 66. As a result, the central portion in the axial direction of the green case 73 bulges outward in the radial direction, and the green case 73 is deformed into a substantially arc shape in cross section. At this time, the belt / tread band 80 is carried to the outside of the green case 73 in the radial direction by the conveying device 81 and is attached to the green case 73. Thereafter, the belt tread band 80 is pressure-bonded to the green case 73 by a stitching device to form a green tire.

    Next, test examples will be described. In this test, both the axially outer side portions of the tire intermediate band were clamped from both sides by a conventional tire in which both axially outer side portions of the tire intermediate band were reduced in diameter only by the swinging blades and the swinging blade and the clamping member. 100 tires each having a reduced diameter were produced. Here, the size of each tire was 37.00R57.

  In each tire, the maximum amplitude of waviness and its variation (maximum amplitude-minimum amplitude) immediately after the reduction of the outer diameter in the axial direction were measured. As a result, in the conventional tire, the maximum amplitude was 123 mm and the variation was 58 mm. However, the maximum amplitude was 73mm and the variation was reduced to 34mm. The wrinkle generation rate for green tires was 87% for conventional tires, but decreased to 3% for implemented tires. Furthermore, the occurrence rate of manufacturing defects such as overlapping of ply cords under the bead in vulcanized tires and stepping at the ply ends was 12% in the conventional tires, but none (0%) in the implemented tires. . In addition, the minimum value of the gauge below the bead and its variation (maximum value-minimum value) of the vulcanized tire were 16.2 mm and 4.3 mm for the conventional tire, respectively, but 18.7 mm and 3.4 mm for the actual tire, respectively. Met.

  The present invention can be applied to an industrial field in which a green tire is manufactured by setting a bead core at a stepped portion after reducing the diameter of an outer portion in the axial direction of a tire intermediate band.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view showing Embodiment 1 of the present invention, in which the upper half shows a state before both side portions in the axial direction of a tire intermediate band are reduced in diameter, and the lower half shows a state after reduced diameter. It is II sectional view taken on the line of FIG. It is a front sectional view explaining the state where a tire middle band is turned up around a bead core. It is a partially broken front view explaining the molding state of a green tire.

Explanation of symbols

11 ... Tire molding drum 17 ... Tire intermediate band
17a ... Axial central part 17b ... Axial outer part
17c ... Step part 32, 33 ... Oscillating blade
40, 41 ... clamping member 60 ... diameter reduction means
66 ... Bead core 67 ... Bead supply means
70 ... Return means

Claims (5)

    A step of supporting the central portion in the axial direction of the cylindrical tire intermediate band by the tire forming drum from the inside in the radial direction, and a substantially axial direction arranged at equal angular intervals on both outer sides in the axial direction of the tire forming drum. A plurality of extending oscillating blades are brought into contact with the outer surface of the outer side in the axial direction of the tire intermediate band located on the outer side in the axial direction from the outer end in the axial direction of the tire forming drum, and in the circumferential direction on the radially inner side of the oscillating blade. Nipping members, which are arranged at an angle and whose number is one-half or more of the swinging blades, are brought into contact with the inner surface of the outer side in the axial direction of the tire intermediate band. Each of the outer portions is clamped, and the swinging blade is sandwiched by the swinging blade and the sandwiching member by synchronously swinging the swinging blade radially inward together with the sandwiching member around the outer end portion in the axial direction. A step of reducing the axially outer side portion of the held tire intermediate band until it becomes smaller than the inner diameter of the bead core, a step of supplying and setting the bead core to the stepped portion formed in the tire intermediate band by the reduced diameter, and A method of manufacturing a green tire, comprising: a step of turning a tire intermediate band axially outside of the bead core around the bead core.     2. The method of manufacturing a green tire according to claim 1, wherein when the number of the swing blades is N, the number of clamping members is a number obtained by multiplying N by a natural number.     The method for manufacturing a green tire according to claim 1 or 2, wherein the holding member is constituted by a rod extending in a straight line having a circular cross section.     The tire intermediate band is formed around a cylindrical band forming drum and then transferred from the band forming drum to the tire forming drum so as to be supported by the tire forming drum. The manufacturing method of the green tire in any one.     A tire forming drum that supports the axial center of the cylindrical tire intermediate band from the inside in the radial direction, and an axially opposite outer side of the tire forming drum that are arranged at equal angular intervals in the circumferential direction, and extend substantially in the axial direction. A plurality of oscillating blades that can come into contact with the outer surface of the outer side in the axial direction of the tire intermediate band located on the axially outer side of the outer end in the axial direction of the tire forming drum; The sandwiching members that are arranged at an equal angle and whose number is 1/2 or more of the swing blades, the swing blades are in contact with the outer surface of the tire intermediate band in the axial direction, and the sandwiching member is the axis of the tire intermediate band. The outer side in the axial direction of the tire intermediate band sandwiched between the swinging blade and the sandwiching member, and the swinging blade in the radial direction together with the sandwiching member about the axial outer end. A diameter reducing means for reducing the diameter until the inner diameter of the bead core is smaller than the inner diameter of the bead core, and a bead supply means for supplying and setting the bead core to the stepped portion formed in the tire intermediate band by the reduced diameter; An apparatus for producing a green tire, comprising: a turning means for turning a tire intermediate band axially outside the bead core around the bead core.

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