JP2010036378A - Manufacturing method of pneumatic tire and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To decrease certainly the deformation amount of the green tire 67 in the vulcanization process while effectively suppressing appearance defects. <P>SOLUTION: Since the axial direction distance between both bead cores 55 in the shaping process is kept much closer than conventionally is done until it becomes the axial direction distance between both bead cores in the pneumatic tire or more and the tire width or less, there are generated, in the vicinities of the radial outer ends of the stiffeners 54, large bends based on rigidity differences. However, onto inner surfaces of the green tire 67 at least at the portions where the radial outer ends of the stiffeners 54 are located, the reshaping members 70, 71 are pushed to produce deformation outward of the axial direction, and so the bends are changed to gradual curves, and the bends can be suppressed effectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

    The present invention relates to a pneumatic tire manufacturing method and apparatus for manufacturing a pneumatic tire by pasting a belt tread band on a carcass band to form a green tire and then vulcanizing the green tire.

As a conventional method and apparatus for manufacturing a pneumatic tire, for example, the one described in Patent Document 1 below is known.
JP 2002-067184 A

  This is a cylindrical carcass band in which a pair of stiffener bead cores is set, while supporting the bead cores from the inside in the radial direction, bringing the bead cores close to each other and supplying pressurized gas into the carcass band between the bead cores. Then, the carcass band between the bead cores bulges outward in the radial direction, while a cylindrical belt tread band is supplied to the outer side in the radial direction of the carcass band so that the belt tread is radially outward of the carcass band. It comprises a shaping process for attaching a band to form a green tire, and a vulcanizing process for vulcanizing the formed green tire into a pneumatic tire.

  In recent years, in order to reduce the amount of deformation of the raw tire in the vulcanization process, that is, the difference between the shape of the raw tire before vulcanization and the shape of the pneumatic tire after vulcanization, immediately before the end of the shaping process. Until the axial distance between the two bead cores becomes a value that approximates the distance between the two bead cores in a pneumatic tire, the two bead cores are made much closer than before, thereby making the meridian cross-sectional shape of the raw tire approximately toroidal. Has been proposed.

    Here, since the stiffener or the like having a large bending rigidity is arranged in the bead portion of the green tire described above, the bending rigidity of the bead portion is a large value, but is positioned on the outer side in the radial direction of the bead portion. Since only the carcass layer and the side tread having a small bending rigidity are arranged in the side wall part, the bending rigidity of the side wall part is considerably smaller than that of the bead part.

  For this reason, in the shaping process as described above, the pressure gas (typically low pressure air of about 100 to 200 kPa is used in order to avoid cord turbulence and the like in the carcass band between the two bead cores in a state in which both bead cores are much closer than before. ), The bead portion of the green tire cannot be sufficiently expanded (oscillated) until it exceeds the upright position with the expansion force by the pressure gas described above, and the position shown in FIG. 6 is limited. is there.

  As a result, a bent portion 2 having a large and abrupt substantially square shape due to a rigidity step is generated near the boundary between the bead portion B and the sidewall portion S, that is, near the radially outer end of the stiffener 1. When a raw tire having such a bent portion 2 is vulcanized as it is, a large gap is generated between the vulcanization mold and the bent portion 2, so that the pneumatic tire (vulcanized tire) in the portion is subjected to There was a problem that appearance defects such as bare (rubber flow failure) and chris (grooved wrinkles) occurred.

  An object of the present invention is to provide a method and an apparatus for manufacturing a pneumatic tire capable of reliably reducing the amount of deformation of a raw tire in a vulcanization process while effectively suppressing the appearance defect of the pneumatic tire. To do.

    The first object is to bring the bead cores close to each other while supporting the bead cores of the cylindrical carcass band in which a pair of bead cores with stiffeners are set from the inside in the radial direction, and the carcass band between the bead cores. A pressure gas is supplied into the inside to cause the carcass band between the bead cores to bulge outward in the radial direction, while a cylindrical belt tread band is supplied to the outside of the carcass band in the radial direction to A method for producing a pneumatic tire, comprising: a shaping step of forming the raw tire by attaching the belt tread band to the outside; and a vulcanization step of vulcanizing the formed raw tire to form a pneumatic tire. The approaching movement of the bead core in the shaping step is the axial distance between both bead cores. This is performed until the tire width is equal to or greater than the axial distance between the two bead cores in the pneumatic tire, and in the shaping step, at least the shaping member is pressed against the inner surface of the raw tire where the radial outer end of the stiffener is located. This can be achieved by a method for manufacturing a pneumatic tire that is deformed outward in the axial direction.

  Second, while supporting the bead cores of a cylindrical carcass band in which a pair of bead cores with stiffeners are set from the inside in the radial direction, the bead cores are brought close to each other and pressure gas is supplied into the carcass band between the bead cores. Then, the carcass band between the bead cores bulges outward in the radial direction, while a cylindrical belt tread band is supplied to the outer side in the radial direction of the carcass band so that the belt tread is radially outward of the carcass band. A pneumatic tire manufacturing method, comprising: a shaping process for forming a green tire by attaching a band; and a vulcanizing process for vulcanizing the formed green tire to form a pneumatic tire, wherein the shaping process and the vulcanization process are performed. During the vulcanization process, the bead core is placed between the two bead cores in the axial direction. The tire is approached until it is greater than the axial distance between the bead cores and less than the tire width, and at least the shaping member is pressed against the inner surface of the raw tire where the radially outer end of the stiffener is located to be deformed outward in the axial direction. This can be achieved by a method for manufacturing a pneumatic tire provided with an intermediate process.

  Thirdly, by moving the bead lock body in the axial direction, a pair of bead lock bodies that can respectively support the bead core of the cylindrical carcass band in which a pair of bead cores with stiffeners is set from the inside in the radial direction. A moving mechanism capable of bringing the bead cores close to each other, and when the bead cores are close to each other, a pressure gas is supplied into the carcass band between the bead cores to bulge the carcass band between the bead cores outward in the radial direction. A rotatable shaping drum having a bulging mechanism, and when the carcass band bulges radially outward, a cylindrical belt tread band is supplied radially outward of the carcass band to provide the carcass band The belt and tread band are pasted on the outside in the radial direction to form a green tire Supply means and a vulcanization mold for vulcanizing the molded green tire to form a pneumatic tire, and the moving mechanism allows the bead core to approach, and the axial distance between the bead cores is the pneumatic tire. Until the tire width is equal to or greater than the axial distance between the two bead cores, and at least the radial outer end of the stiffener is pressed against the inner surface of the raw tire so that the raw tire of the part is axially This can be achieved by a pneumatic tire manufacturing apparatus provided with a shaping member that deforms outward.

  In the invention according to claim 1, the bead core in the shaping step is much closer than before until the axial distance between both bead cores is greater than the axial distance between both bead cores in the pneumatic tire and less than the tire width. Therefore, a large bend based on the rigidity step occurs near the radially outer end of the stiffener, but at least the shaping member is pressed against the inner surface of the raw tire where the radially outer end of the stiffener is located. Since the raw tire is deformed outward in the axial direction, the above-described bending changes to a gentle curve, and the above-described bending is effectively suppressed.

  As a result, when the raw tire is vulcanized, the gap between the vulcanization mold and the raw tire near the radially outer end of the stiffener is close to the gap of the other part. It is possible to effectively suppress such appearance defects. Moreover, since the whole raw tire has a bead core that is very close, it has a shape approximating that of a pneumatic tire, and as a result, the amount of deformation of the raw tire in the vulcanization process can be reduced reliably.

  Such a pneumatic tire can be easily manufactured by using the invention according to claim 5. Further, as in the invention according to claim 2, in the intermediate step between the shaping step and the vulcanization step, the bead core is made much closer than before and at least the radially outer end portion of the stiffener is positioned by the shaping member. If the raw tire of the part is deformed to the outside in the axial direction, it is possible to effectively suppress defects in appearance such as bear and chris while facilitating the work.

  Further, if configured as described in claim 3, the raw tire can be sufficiently expanded (swinged) until it exceeds the upright position in a wide range from the bead core to the radial outer end of the stiffener. As a result, the shape of the raw tire can be regulated to a shape substantially similar to that of the pneumatic tire, and the appearance defect and the deformation amount of the raw tire in the vulcanization process can be further effectively suppressed. Furthermore, if constituted as described in claim 4, it is possible to strongly reduce the appearance defect and the amount of deformation of the green tire in the vulcanization process.

Embodiment 1 of the present invention will be described below with reference to the drawings.
In FIG. 1, reference numeral 11 denotes a shaping drum that can rotate around an axis, and the shaping drum 11 has a horizontal cylindrical drum main shaft 12. The drum main shaft 12 is connected to a drive unit (not shown), and is driven and rotated as necessary by the drive unit. A screw shaft 13 coaxial with the drum main shaft 12 is rotatably inserted into the drum main shaft 12, and male screw portions 14 and 15 that are reverse screws are formed on the outer periphery of both sides in the axial direction of the screw shaft 13, respectively. Has been.

  In addition, a plurality of slits 16 and 17 extending in the axial direction are formed in the drum main shaft 12 in a portion overlapping with the male screw portions 14 and 15, respectively, and these slits 16 and 17 are arranged equidistantly in the circumferential direction. . Reference numerals 18 and 19 denote screw members which are screwed into the male screw portions 14 and 15, respectively. Connection blocks 20 and 21 penetrating the slits 16 and 17 are fixed to the screw members 18 and 19, respectively.

  25 and 26 are substantially cylindrical sliding bodies supported on the both sides in the axial direction of the drum main shaft 12 so as to be movable in the axial direction, and surround the drum main shaft 12. Blocks 20 and 21 are connected to each other. A plurality of storage holes 27, 28 extending in the radial direction are formed on the outer periphery of the inner side in the axial direction of the sliding bodies 25, 26, and these storage holes 27, 28 are arranged equidistantly in the circumferential direction, respectively. .

  Bead lock segments 29 and 30 are inserted into the respective storage holes 27 and 28 so as to be movable in the radial direction, and rollers 31 and 32 are rotatable at inner ends of the bead lock segments 29 and 30, respectively. It is supported. The plurality of bead lock segments 29, the roller 31 and the plurality of bead lock segments 30, and the roller 32 constitute bead lock bodies 33 and 34, respectively. The bead cores of the cylindrical carcass band in which the bead cores with stiffeners are set can be supported from the inside in the radial direction.

  37 and 38 are cylinder chambers formed in the sliding bodies 25 and 26 and having a ring shape coaxial with the drum main shaft 12, and the inner ends in the axial direction of the cylinder chambers 37 and 38 are the radii of the storage holes 27 and 28. It communicates with the inner end of the direction. Reference numerals 39 and 40 denote ring-shaped pistons housed in the cylinder chambers 37 and 38 so as to be movable in the axial direction. The pistons 39 and 40 have an axially inner side extending from the axially outer side toward the axially inner side. Accordingly, conical inclined surfaces 41 and 42 are formed which incline toward the inner side in the radial direction and to which the rollers 31 and 32 are in rolling contact.

  45 and 46 are fluid passages communicating with the cylinder chambers 37 and 38 axially outside the pistons 39 and 40. When high-pressure fluid is supplied from the high-pressure fluid source to the cylinder chambers 37 and 38 through the fluid passages 45 and 46, respectively. The pistons 39 and 40 move inward in the axial direction, and the bead lock segments 29 and 30 are synchronously moved outward in the radial direction by the inclined surfaces 41 and 42. 47 and 48 are substantially cylindrical sealing members made of a thin rubber sheet whose axial central portion is bent into a dogleg shape, and the inner ends of these sealing members 47 and 48 are in the radial direction of all the beadlock segments 29 and 30. The outer end surfaces are in close contact with each other, while the outer end portions are hermetically locked to the sliding bodies 25 and 26.

  As a result, the bead lock segments 29 and 30 move radially outward to create gaps between adjacent bead lock segments 29 and bead lock segments 30, and pressure gas leaks axially outward through these gaps. Even if it tries to come out, the leakage is prevented by the sealing members 47 and 48. In addition, when the supply of high-pressure fluid to the cylinder chambers 37 and 38 is stopped, the seal members 47 and 48 move the bead lock segments 29 and 30 inward in the radial direction by the elastic restoring force.

  The cylinder chambers 37 and 38, the pistons 39 and 40, the fluid passages 45 and 46, and the seal members 47 and 48 described above constitute an expansion / contraction mechanism 49 that expands / contracts the bead lock bodies 33 and 34 as a whole. In the present invention, the expansion / contraction mechanism may be composed of a pair of cylinder cases that reciprocate in the axial direction and a plurality of links that connect the cylinder cases and the bead lock segments. Further, a drive motor (not shown) is connected to the screw shaft 13. As a result, when the drive motor is operated and the screw shaft 13 is driven and rotated, the sliding bodies 25 and 26 are reverse screws. The male screw parts 14 and 15 are moved by an equal distance in the opposite direction, and approach and separate from each other.

  The screw shaft 13, the screw members 18, 19, the connecting blocks 20, 21, and the drive motor described above as a whole have the sliding body 25, the bead lock body 33 and the sliding body 26, and the bead lock body 34 in the opposite directions in the axial direction. The moving mechanism 50 that can be moved closer to and away from each other is configured. As described above, when the bead core 55 is supported from the radially inner side by the bead lock bodies 33 and 34, when the moving mechanism 50 is activated and the bead lock bodies 33 and 34 move inward in the axial direction, the bead locks are moved. The bead cores 55 supported by the bodies 33 and 34 approach each other.

  In FIG. 2, 53 is a cylindrical carcass band made of a carcass layer with an inner liner affixed to the inner periphery, and a pair of bead cores 55 with stiffeners 54 are set at both axial ends of the carcass band 53. Around the bead core 55, a carcass layer axially outside the bead core 55 is folded. Further, in this embodiment, side treads 56 are wound around the outer ends of the carcass band 53 in the axial direction.

  Then, such a cylindrical carcass band 53 and the like are molded on a molding drum (not shown) and then conveyed to the shaping drum 11 by a conveying device, and are fitted to the outside of the shaping drum 11 as shown in FIG. Is done. Thereafter, when the bead lock segments 29 and 30 are synchronously moved radially outward, the bead core 55 is supported from the radially inner side by the bead lock bodies 33 and 34 via the carcass band 53.

  Referring again to FIG. 1, 58 is a gas passage formed in the sliding body 26, one end of the gas passage 58 opens to the inner end surface in the axial direction of the sliding body 26, and the other end is a pressure gas source (not shown). For example, a low-pressure air source of about 100 to 200 kPa is connected in order to avoid the cord disturbance of the carcass band 53. As described above, when the bead cores 55 are approaching each other due to the movement of the bead lock bodies 33 and 34 in the axial direction, the pressure gas is supplied from the pressure gas source through the gas passage 58 into the carcass band 53 between the bead cores 55. When supplied, the carcass band 53 between the bead cores 55 bulges outward in the radial direction so as to have a substantially arc-shaped cross section.

  As described above, the gas passage 58 and the pressure gas source as a whole supply pressure gas into the carcass band 53 between the bead cores 55 when the bead cores 55 are close to each other, so that the carcass band 53 between the bead cores 55 is radially outward. A bulging mechanism 59 for bulging is configured. At this time, the pressure gas that has passed through the gap between the bead lock segments 29 and 30 adjacent in the circumferential direction is prevented from leaking to the outside by the seal members 47 and 48. As described above, the shaping drum 11 includes the bead lock bodies 33 and 34, the moving mechanism 50, and the bulging mechanism 59.

  In the above-described embodiment, the carcass layer 53 constituting the carcass band 53 is folded around the bead core 55 and the side tread 56 is wound around the shaping drum 11 before being carried into the shaping drum 11. In the shaping process in which the carcass layer 53 and the side tread 56 located on the outer side in the axial direction from the bead core 55 are carried into the shaping drum 11 after the carcass band 53 is carried into the shaping drum 11, and the carcass band 53 is bulged outward in the radial direction. The bead core 55 may be folded back.

  In FIG. 3, reference numeral 63 denotes a belt tread band which is formed into a cylindrical shape by a band forming machine (not shown). The belt tread band 63 is a belt layer 64 and a top attached to the outer side in the radial direction of the belt layer 64. It consists of a tread 65. When the carcass band 53 bulges outward in the radial direction, the belt-tread band 63 is gripped from the outside by the substantially cylindrical supply means 66, and the belt-tread band 63 extends outward in the radial direction of the carcass band 53. By being supplied, the carcass band 53 is attached to the outside in the radial direction. Thereafter, the belt tread band 63 is pressed against the carcass band 53 by a stitching device (not shown) to form a green tire 67 as shown in FIG. The raw tire 67 described above may be formed by a shaping drum capable of forming a carcass band, that is, a single stage type drum.

  1, 2, 3, 4, 70 and 71 are shaped parts 72 and 73, and the base ends are integrally connected to the base ends of the shaped parts 72 and 73, and the length is shorter than the shaped parts 72 and 73. A plurality of shaping members composed of the arm portions 74, 75, and the shaping portions 72, 73 of the shaping members 70, 71 and the arm portions 74, 75 intersect at a predetermined angle. The shaping members 70 and 71 have a substantially letter shape in cross section. These shaping members 70 and 71 are made of a rigid body such as metal or plastic with substantially the same thickness.

  Reference numerals 78 and 79 denote a plurality of brackets attached to the radially outer end portions on the inner end surfaces in the axial direction of the sliding bodies 25 and 26, and these brackets 78 and 79 are arranged equidistantly in the circumferential direction. The brackets 78 and 79 are connected to the intersections of the shaping members 70 and 71 so as to be rotatable. 80 and 81 are a plurality of axially extending servo cylinders whose rod side is fixed to the axial outer end surfaces of the sliding bodies 25 and 26. The piston rods 82 and 83 of these servo cylinders 80 and 81 are connected to the sliding bodies 25 and 26. It penetrates and projects inward from the inner end surface in the axial direction of the sliding bodies 25 and 26.

  A connecting ring 86 coaxial with the drum spindle 12 is fixed to the tip of the piston rod 82 of the servo cylinder 80, and a connecting ring 86 coaxial with the connecting ring 86 is fixed to the tip of the piston rod 83 of the servo cylinder 81. ing. An inner end of a connection link 89 is rotatably connected to the connection ring 86 via a plurality of brackets 88, and an outer end of the connection link 89 is rotatable to the tip of the arm portion 75 of the shaping member 71. It is connected. On the other hand, the inner ends of the connection links 91 are rotatably connected to the connection ring 87 via a plurality of brackets 90, and the outer ends of the connection links 91 are rotated to the tips of the arm portions 74 of the shaping member 70. Connected as possible.

  When the servo cylinders 80 and 81 are operated and the piston rods 82 and 83 are protruded or retracted, the shaping members 71 and 70 are centered on the intersecting portion, and the shaping portions 73 and 72 are axially moved as shown in FIG. Can be swung between the lying position R substantially parallel to the expansion position T and the expanding position T where the shaping portions 73 and 72 are expanded until they exceed the upright position as shown in FIG. The servo cylinders 80 and 81, the connecting rings 86 and 87, and the connecting links 89 and 91 as described above press the shaping portions 72 and 73 against the inner surface of the raw tire 67 by swinging the shaping members 70 and 71 as a whole. A swing mechanism 92 that can

  Here, immediately before the end of the shaping process described later, the moving mechanism 50 causes the axial distance between the bead cores 55 to be equal to or greater than the axial distance between the bead cores 55 in the pneumatic tire 95, and the tire width in the pneumatic tire 95. When the bead cores 55 of the raw tire 67 are brought close to each other until the following, the bending stiffness of the stiffener 54 and the like is large, so pressure gas is supplied into the carcass band 53 (raw tire 67) between the bead cores 55. However, the bead portion B of the raw tire 67 cannot be sufficiently expanded (oscillated), and a substantially U-shaped bent portion based on the rigidity step is generated near the radially outer end of the stiffener 54. End up.

  For this reason, in this embodiment, the shaping members 70 and 71 are swung to the expanded position T in the shaping step (immediately before the end) in which the axial distance between the bead cores 55 is made much closer than before. By moving, the shaping portions 72 and 73 are pressed against the inner surface of the raw tire 67 at least at the portion where the radially outer end portion of the stiffener 54 is located, thereby deforming the portion outward in the axial direction. is there. Thereby, the above-mentioned bending changes into a gentle curve, and the bending is effectively suppressed.

  As a result, when vulcanizing the raw tire 67, the gap between the vulcanization mold 94 and the raw tire 67 in the vicinity of the radially outer end of the stiffener 54 is different from that of the vulcanization mold 94 in other parts. It becomes close to the gap between the raw tires 67, thereby effectively suppressing appearance defects such as bear and chris. Moreover, since the whole raw tire 67 has a bead core 55 that is very close, it has a shape that approximates that of a pneumatic tire 95, and as a result, the amount of deformation of the raw tire 67 in the vulcanization process can be reliably reduced.

  The vulcanization mold 94 described above can be composed of, for example, a lower mold 96 as shown in FIG. 5, an upper mold 97 that can be raised and lowered, and a plurality of sector molds 98 that can move synchronously in the radial direction. Then, after storing the molded raw tire 67 in such a vulcanization mold 94, a high-temperature, high-pressure vulcanization medium is supplied to the bladder 99 and vulcanized. And In the present invention, the raw tire 67 may be vulcanized using a vulcanization mold composed of a mold that is divided into two vertically.

  Here, the shaping portions 72 and 73 of the shaping members 70 and 71 described above extend from the bead core 55 to beyond the radial outer end of the stiffener 54, and the outer surface shape of the shaping portions 72 and 73 is a pneumatic tire. It is preferable to approximate the inner surface shape of 95. The reason for this is that the raw tire 67 can be sufficiently expanded (swinged) until it exceeds the upright position in a wide range from the bead core 55 to the radial outer end of the stiffener 54. As a result, the shape of the raw tire 67 can be defined to be substantially the same shape as the pneumatic tire 95, and the amount of deformation of the raw tire 67 in the vulcanization process can be further effectively suppressed. is there.

  Further, the axial distance between the bead cores 55 in the raw tire 67 described above is substantially the same as the axial distance between the bead cores 55 in the pneumatic tire 95, and the shaping parts 72, 73 of the shaping members 70, 71 If the outer surface shape is substantially the same as the inner surface shape of the pneumatic tire 95, it is more preferable because the appearance defect and the amount of deformation of the raw tire 67 in the vulcanization process can be strongly reduced.

  Here, the shaping portions 72 and 73 of the shaping members 70 and 71 described above have a substantially fan shape in which the circumferential length increases from the proximal end toward the distal end as shown in FIG. A wide range of the inner surface of the raw tire 67 can be pressed almost uniformly. However, if the shaping portions 72 and 73 have a substantially fan shape in this way, when the shaping portions 72 and 73 swing to the fall position R, the shaping portions 72 and 73 adjacent in the circumferential direction may interfere with each other.

  Therefore, in this embodiment, of the shaping units 72 and 73, the odd-numbered shaping units 72 and 73 from any one shaping unit 72 and 73 are moved earlier than the even-numbered shaping units 72 and 73. By swinging from the spread position T to the lying position R, the adjacent shaping portions 72 and 73 are prevented from interfering at the lying position R. In the present invention, as the swing mechanism, a cylinder in which the tip of the piston rod is connected to the shaping members 70, 71 is used, or a fan-shaped external gear is provided instead of the arm portions 74, 75, A rack meshing with the gear may be reciprocated by a cylinder or the like.

Next, the operation of the first embodiment will be described.
First, a pair of bead cores 55 with stiffeners 54 is set by the forming drum, and after forming a cylindrical carcass band 53 around which a side tread 56 is wound, the carcass band 53 and the like are conveyed by a conveying device (not shown). Is conveyed from the forming drum to the shaping drum 11 and is fitted to the outside of the shaping drum 11 as shown in FIG. At this time, since the shaping members 70 and 71 are both in the lying position R, the carcass band 53 and the like and the shaping members 70 and 71 do not interfere with each other during the fitting.

  Next, high pressure fluid is supplied from the high pressure fluid source to the cylinder chambers 37 and 38 through the fluid passages 45 and 46 of the expansion / contraction mechanism 49 to move the pistons 39 and 40 inward in the axial direction, and the bead lock segments 29 and 30 are inclined. 41 and 42 are synchronously moved radially outward. When the radially outer ends of the bead lock segments 29 and 30 come into contact with the bead core 55 via the carcass band 53, the bead core 55 is supported from the radially inner side by the bead lock bodies 33 and 34, respectively.

  Next, when the drive motor of the moving mechanism 50 is operated to drive and rotate the screw shaft 13, the sliding bodies 25 and 26 are moved inward in the axial direction by the male screw portions 14 and 15 which are reverse screws, Thus, the pair of bead cores 55 supported by the bead lock bodies 33 and 34 approach each other. At this time, a pressure gas, for example, low-pressure air of about 100 to 200 kPa, is supplied from a pressure gas source into the carcass band 53 between the bead cores 55 through the gas passage 58, and the radius is such that the carcass band 53 between the bead cores 55 has a substantially arcuate cross section. The bulge is deformed outward in the direction.

  At this time, the formed belt-tread band 63 having a cylindrical shape is supplied to the outer side in the radial direction of the carcass band 53 while being gripped from the outside by the supply means 66, and the belt-tread band 63 is supplied as shown in FIG. Affix to the outside of the carcass band 53 in the radial direction. At this time, the servo cylinders 80 and 81 are operated to retract the piston rods 82 and 83, and the shaping members 71 and 70 are moved from the lying position R toward the expanded position T around the intersection, Oscillate (expand) while avoiding contact.

  Next, the belt / tread band 63 is pressure-bonded to the carcass band 53 by a stitching device while the shaping drum 11 is rotated around the axis by the drive unit, and the raw tire 67 is formed. Immediately before the end of the shaping process, the moving mechanism 50 is actuated again until the axial distance between the bead cores 55 is significantly smaller than before, that is, the axial distance between the bead cores 55 is inflated. Until the tire width is equal to or greater than the axial distance between the two bead cores 55 in the tire 95, the tires 95 are brought closer to each other until the axial distance between the two bead cores 55 in the pneumatic tire 95 is substantially the same.

  At this time, since the bending stiffness of the stiffener 54 and the like is large, even if a low-pressure gas is supplied into the carcass band 53 (raw tire 67), a bent portion based on a rigidity step is provided near the radially outer end of the stiffener 54. In this embodiment, at this time, the shaping members 70 and 71 are swung to the expansion position T by the rocking mechanism 92, so that the shaping portions 72 and 73 are at least radially outward of the stiffener 54. The part where the part is located, here, the wide range from the bead core 55 to the radial outer end of the stiffener 54 over the shaping parts 72, 73 whose outer surface shape is substantially the same shape as the inner surface shape of the pneumatic tire 95 Then, it was pressed against the inner surface of the raw tire 67, whereby the pressed portion was deformed outward in the axial direction until it became substantially the same shape as the pneumatic tire 95.

  As a result, the above-described bending changes to a gentle curve, and the above-described bending is effectively suppressed. The pressing by the shaping members 70 and 71 (the shaping portions 72 and 73) described above is performed when the belt tread band 63 is attached to the carcass band 53, or after that, the carcass band of the belt tread band 63 by a stitching device. It may be started from the time of crimping to 53, or may be started after the bead core 55 is made much closer than before. In this way, the shaping process in the shaping drum 11 is completed.

  Next, the raw tire 67 that has been deformed and smoothed as described above is taken out of the shaping drum 11 and placed on the lower mold 96 of the vulcanizing mold 94 in a horizontally placed state, and then the upper mold 97 is lowered. At the same time, the sector mold 98 is synchronously moved radially inward to close the vulcanization mold 94, and the raw tire 67 is stored in the vulcanization mold 94. Next, a high temperature and high pressure vulcanization medium is supplied to the bladder 99 to vulcanize the raw tire 67, and the raw tire 67 is used as a pneumatic tire 95.

  At this time, since the bent portion of the raw tire 67 was gently changed to a curve approximating the pneumatic tire 95 as described above, the raw tire 67 in the vicinity of the radially outer end of the vulcanization mold 94 and the stiffener 54 The gap between the two becomes close to the gap in other parts, and thereby, appearance defects such as bear and chris can be effectively suppressed. Moreover, since the whole raw tire 67 has a bead core 55 that is very close, the shape of the raw tire 67 is similar to that of the pneumatic tire 95. As a result, the amount of deformation of the raw tire 67 during vulcanization can be reliably reduced. In this way, the vulcanization process using the vulcanization mold 94 is completed.

    In the above-described embodiment, in the shaping drum 11, the bead core 55 is made much closer than before, and the shaping members 70 and 71 are pressed against the raw tire 67 and deformed outward in the axial direction. In this case, the raw tire 67 molded by the shaping drum 11 is taken out from the shaping drum 11 and supported by an intermediate stand, an intermediate drum, etc. It is also possible to press the shaping member provided on the raw tire 67 and deform it outward in the axial direction, and then vulcanize the raw tire 67 by the vulcanizing mold 94.

  In this case, an intermediate process is provided between the shaping process and the vulcanization process, and in this intermediate process, the bead core 55 is axially spaced between the two bead cores 55 in the pneumatic tire 95. It is made to approach until it becomes equal to or greater than the distance and equal to or less than the tire width, and is deformed outward in the axial direction by pressing a shaping member such as an intermediate platform on the inner surface of the raw tire 67 at least where the radial outer end of the stiffener 54 is located Become. And, in this way, it is possible to effectively suppress appearance defects such as bear and chris as described above, and it is not necessary to consider interference with surrounding equipment such as a stitching device. Becomes easy.

  The present invention can be applied to the industrial field of manufacturing a pneumatic tire by pasting a belt tread band on a carcass band to form a green tire and then vulcanizing the green tire.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view of a shaping drum and a green tire showing Embodiment 1 of the present invention. It is front sectional drawing similar to FIG. 1 explaining the carrying-in state to the shaping drum of a carcass band. It is front sectional drawing similar to FIG. 1 explaining the sticking state to the carcass band of a belt tread band. It is the II arrow directional view of FIG. It is a front sectional view explaining the vulcanization state of a green tire. It is front sectional drawing similar to FIG. 1 explaining the conventional raw tire shape.

Explanation of symbols

11 ... Shaping drum 33, 34 ... Bead lock body
50 ... Movement mechanism 53 ... Carcass band
54… Stiffener 55… Bead Core
59 ... Swelling mechanism 63 ... Belt tread band
66 ... Supply means 67 ... Raw tires
70, 71 ... Shaping member 94 ... Vulcanizing mold
95 ... Pneumatic tire

Claims (5)

    While supporting the bead cores of a cylindrical carcass band in which a pair of bead cores with stiffeners are set from the inside in the radial direction, the bead cores are brought close to each other, and pressure gas is supplied into the carcass band between the bead cores between the bead cores. The carcass band of the carcass band bulges outward in the radial direction, and a cylindrical belt tread band is supplied to the outer side of the carcass band in the radial direction so that the belt tread band is attached to the outer side of the carcass band in the radial direction. A pneumatic tire manufacturing method comprising a shaping step of molding a tire and a vulcanization step of vulcanizing the formed green tire to form a pneumatic tire, wherein the bead core approaches and moves in the shaping step The axial distance between the bead cores in the pneumatic tire. This is performed until the tire width is equal to or greater than the axial distance between the two bead cores, and in the shaping step, at least the shaping member is pressed against the inner surface of the raw tire where the radially outer end portion of the stiffener is located to be axially outward. A method for producing a pneumatic tire, characterized by being deformed.     While supporting the bead cores of a cylindrical carcass band in which a pair of bead cores with stiffeners are set from the inside in the radial direction, the bead cores are brought close to each other, and pressure gas is supplied into the carcass band between the bead cores between the bead cores. The carcass band of the carcass band bulges outward in the radial direction, and a cylindrical belt tread band is supplied to the outer side of the carcass band in the radial direction so that the belt tread band is attached to the outer side of the carcass band in the radial direction. A method for manufacturing a pneumatic tire, comprising: a shaping step for forming a tire; and a vulcanization step for vulcanizing the formed green tire to form a pneumatic tire, comprising the shaping step and the vulcanization step. Between the bead cores, the axial distance between both bead cores is the pneumatic tire An intermediate that is made to approach until it becomes more than the axial distance between both bead cores and less than the tire width, and at least deforms outward in the axial direction by pressing the shaping member on the inner surface of the raw tire where the radial outer end of the stiffener is located A method for producing a pneumatic tire, comprising a step.     3. The pneumatic tire according to claim 1, wherein the shaping member extends from the bead core to beyond the radially outer end of the stiffener, and an outer surface shape of the shaping member is approximated to an inner surface shape of the pneumatic tire. Production method.     The axial distance between the two bead cores described above is substantially the same as the axial distance between the two bead cores in the pneumatic tire, and the outer surface shape of the shaping member is substantially the same as the inner surface shape of the pneumatic tire. The manufacturing method of the pneumatic tire of Claim 3.     A pair of bead lock bodies capable of supporting the bead core of a cylindrical carcass band in which a pair of bead cores with stiffeners are set from the inside in the radial direction, and the bead core is moved by moving the bead lock body in the axial direction. A moving mechanism that can approach each other, and a bulging mechanism that, when the bead cores are close to each other, supplies a pressure gas into the carcass band between the bead cores to bulge the carcass band between the bead cores outward in the radial direction. When the carcass band bulges outward in the radial direction, a cylindrical belt tread band is supplied radially outward of the carcass band so as to be radially outward of the carcass band. Supplying the belt and tread band to a green tire And a vulcanization mold for vulcanizing the molded green tire to form a pneumatic tire, the moving mechanism allows the bead core to approach, and the axial distance between the two bead cores in the pneumatic tire. While it is performed until the tire width is equal to or greater than the axial distance between the bead cores, at least the radial outer end of the stiffener is pressed against the inner surface of the raw tire so that the raw tire of the portion is axially outward. An apparatus for manufacturing a pneumatic tire, comprising a shaping member to be deformed.

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