JP3701087B2 - Tire vulcanizing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a tire vulcanizing method and apparatus for vulcanizing an unvulcanized tire using three types of molds of an upper side, a lower side, and a sector.
[0002]
[Prior art]
If vulcanization is performed in a state where air remains between the unvulcanized tire and the vulcanized mold, traces of residual air remain on the surface of the product tire after vulcanization, causing a bad appearance of the tire. Residual air must be discharged from the vulcanization mold prior to vulcanization. Conventionally, in order to discharge such residual air, a large number of ventilation holes (generally referred to as vent holes) leading from the inner surface of the vulcanization mold to the outside are installed at locations where the air tends to remain. . However, when the vents are installed in this way, a part of the rubber on the surface of the unvulcanized tire enters the vents immediately after the residual air is discharged, so that it is unnecessary on the surface of the product tire after vulcanization. Many needle-like protrusions (generally called spew) are formed, and as a result, there is a problem that a process for cutting and removing these needle-like protrusions is required and the manufacturing cost of the tire is increased.
[0003]
In order to solve such problems, the air remaining in the vulcanization mold is positively exhausted immediately before the vulcanization mold is closed, thereby eliminating or reducing the number of vent holes. A tire vulcanizing method and apparatus has been proposed in, for example, Japanese Patent Publication No. 6-55371. This is a lower base having a lower side mold, an upper base that is installed above the lower base and is separated and approached by moving up and down, and between the lower base and the upper base. A lifting body having an upper side mold, a lifting body that is installed radially outward of the lifting body, an upper end is fixed to the upper base, and an inclined surface that is inclined radially inward as it goes upwards. The outer ring on the inner periphery and the lower surface of the lifting body are supported so as to be movable in the radial direction, and when the outer ring and the upper base are moved up and down, the outer ring can move in the radial direction by the wedge action of the inclined surface of the outer ring. Sector mold, and at least the upper side mold reaches the position 1.0 to 50.8 mm away from the lower limit (position where the sector mold contacts the lower base) and then the outer ring reaches the lower limit Until the outer side and the lower base are sealed to form a sealed space in which an unvulcanized tire is stored, and when the upper side mold is lowered to the position, the sealed space And an exhaust means for exhausting the air inside.
[0004]
And when vulcanizing an unvulcanized tire with such a vulcanizer, first, after unloading the tire into the vulcanizer and placing it on the lower side mold, the upper base, Lower the outer ring, upper side and sector mold together. When the upper side mold reaches a position at least 1.0 to 50.8 mm away from the descending end (position where the sector mold contacts the lower base), the sealing means seals between the outer ring and the lower base. The closed space surrounded by the upper and lower bases and the outer ring to form an unvulcanized tire is formed. Further, when the upper side mold is lowered to the position, the exhaust means exhausts the air in the sealed space to the outside, and the sealed space is set to a predetermined degree of vacuum. After that, the upper base, outer ring, upper side, and sector mold continue to descend together, but the upper side and sector mold are lowered when the upper side mold is at the lower end (the lower end of the sector mold is the lower base). Stops when it reaches the abutting position) and is positioned very close to the unvulcanized tire. After that, the upper base and the outer ring continue to descend independently, so that the sector mold is pushed by the inclined surface of the outer ring and moves inward in the radial direction. When the outer ring reaches its lower limit, the sector mold reaches the radially inner limit, and the vulcanization mold is closed. Thereafter, the unvulcanized tire in the vulcanization mold is vulcanized.
[0005]
[Problems to be solved by the invention]
However, in such a conventional tire vulcanizing method / apparatus, the upper base, outer ring, upper side, and sector mold are combined together, and the upper side mold is spaced 1.0 to 50.8 mm upward from the descending end. When the air is lowered to the position, that is, while the upper base, the outer ring, the upper side, and the entire sector mold are being lowered, the air in the sealed space is discharged to the outside by the exhaust means. During such exhaust, a gap of about 1.0 to 50.8 mm is left between the upper side mold and the unvulcanized tire, while a maximum gap remains between the sector mold and the unvulcanized tire. As a result, there is a problem that the volume of the sealed space for exhausting becomes extremely large, and it takes a long time to make the sealed space have a predetermined degree of vacuum, resulting in low productivity. Moreover, as described above, when exhaust is performed in a state where a wide gap exists between the unvulcanized tire and the upper side, sector mold, the unvulcanized tire easily grows and deforms. There is also a problem that the quality of the product tire is deteriorated because the unvulcanized tire is peeled off from the vulcanized bladder or a part of the unvulcanized tire is caught between the vulcanization molds.
[0006]
An object of the present invention is to provide a tire vulcanizing method and apparatus that can shorten the exhaust time and improve the quality of a product tire.
[0007]
[Means for Solving the Problems]
    The first purpose is to first lower the upper side mold together with the outer ring to the lower end of the upper side mold, and then lower the outer ring alone to the lower limit N of the outer ring. In the tire vulcanization method in which the sector mold is moved to the inner limit in the radial direction by the wedge action of the inclined surface to close the vulcanization mold and then vulcanize the unvulcanized tire in the vulcanization mold. ,When the outer ring is loweredThe space in which the unvulcanized tire is stored is sealed by the sealing means from just before the outer ring reaches the position P 10-25 mm away from the lower limit N until the lower limit N is reached. When the ring descends to the position P, secondly, a tire vulcanization method that exhausts air in the sealed space to the outside, and secondly, a lower base having a lower side mold, and an upper part of the lower base The upper base that is separated and approaches the lower base by being lifted and lowered, and is installed so that it can be raised and lowered between the lower base and the upper base. Installed radially outward, the upper end is fixed to the upper base, and the outer ring has an inclined surface that is inclined radially inward as it goes upward, and can be moved in the radial direction on the lower surface of the elevator Supported and out And a sector mold that can move in the radial direction by the wedge action of the inclined surface of the outer ring when the upper base is raised and lowered, and the upper side and the sector mold are sectored together with the upper base and the outer ring. After the mold is lowered to the lower end of the upper side mold that comes into contact with the lower base, the upper base and the outer ring are independently lowered to the lower limit N of the outer ring, and the sector is caused by the wedge action of the inclined surface of the outer ring. In the tire vulcanizing apparatus that moves the mold to the inner limit in the radial direction, closes the vulcanized mold, and then vulcanizes the unvulcanized tire in the vulcanized mold.When the outer ring is loweredUntil the outer ring reaches the lower limit N immediately before reaching the position P that is 10-25 mm away from the lower limit N, the space between the outer ring and the lower base is sealed to store the unvulcanized tire. This is achieved by a tire vulcanizing apparatus provided with a sealing means for forming a sealed space, and provided with an exhaust means for discharging the air in the sealed space to the outside when the outer ring descends to the position P. Can do.
[0008]
  When vulcanizing an unvulcanized tire, first, the unvulcanized tire is carried into a vulcanizing apparatus and placed on the lower side mold. Next, the upper base, the outer ring, the upper side, and the sector mold are lowered together to bring the upper side mold closer to the unvulcanized tire. When the lower end of the sector mold comes into contact with the lower base and the upper side mold reaches its lower end, the lower side of the upper side and the sector mold stops. They are located close to each other and there is almost no gap between them. In addition, since the upper base and the outer ring continue to descend independently after the upper side and the sector mold are stopped descending, the sector mold is pushed by the inclined surface of the outer ring that is descending while being supported by the lifting body. Moves radially inward and approaches the unvulcanized tire. When such an outer ring is lowered, the sealing means seals between the outer ring and the lower base to form a sealed space in which the unvulcanized tire is stored. To the position P 10-25mm away from the lower limit NJust before reachingUntil reaching the descent limit NBetween, lineIs called. When the outer ring descends to the position P, the exhaust means discharges the air in the sealed space to the outside and sets the sealed space to a predetermined degree of vacuum. Here, at the time of such exhaust, there is almost no gap between the upper side mold and the unvulcanized tire as described above, while there is a slight gap between the sector mold and the unvulcanized tire. That is, the outer ring is in position PJust beforeSince there is only a distance that the sector mold is pushed and moved while moving from the lower limit N to the lower limit N, the volume of the space to be evacuated is reduced, and as a result, the evacuation time until a predetermined degree of vacuum is achieved. It is shortened and productivity is improved. Moreover, as described above, since there is almost no gap between the vulcanized mold and the unvulcanized tire, growth and deformation of the unvulcanized tire during exhaust (particularly deformation in the width direction) are limited, As a result, a situation in which the unvulcanized tire is peeled off from the vulcanization bladder or a part of the unvulcanized tire is caught between the vulcanization molds is prevented, and the quality of the product tire is improved. When the outer ring reaches its lowering limit N, the sector mold reaches the radially inner limit, and the upper, lower side, and sector molds are closed. Thereafter, the unvulcanized tire in the vulcanization mold is vulcanized.
[0009]
According to the third aspect of the present invention, the upper and lower side molds can adsorb and hold the bead portion of the unvulcanized tire when exhausting from the sealed space. Peeling and deformation from the sulfur bladder are further restricted, and the quality of the product tire is further improved. Further, a sealing means for preventing air from entering between the upper and lower side molds and the bead portion of the unvulcanized tire, for example, an O-ring can be omitted, and the structure is simplified.
Furthermore, since the tire vulcanizer of the prior art is designed to fix the outer ring to the upper base only at the upper end, the outer ring cannot be provided with sufficient mounting accuracy, particularly centering accuracy, and the mold If the outer ring receives a large reaction force from the sector mold when the outer ring is closed, the outer ring may slightly wobble. As a result, the mold may be insufficiently closed. Since the position of the ring is regulated by the first cylindrical surface and the centering member and becomes highly accurate, the assembly accuracy of the outer ring, particularly the centering accuracy can be increased, and the wobbling of the outer ring can be prevented. Since it can be firmly regulated by the center shaft via the centering member, Wobble can be effectively suppressed. Since the centering accuracy described above becomes higher as the sliding surfaces of the two members are radially inward, the first plate and the second cylindrical surface are both the upper plate and the inner end of the centering member in the radial direction as described above. The centering accuracy is improved by providing it in the section.Moreover, if comprised as described in Claim 5, the tire external appearance defect by the trace of residual air can be suppressed within a specification.
Furthermore, if it comprises as described in Claim 6, a centering member will not become obstructive at the time of replacement | exchange of a mold, and carrying in / out of a mold becomes easy.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
In FIG. 1, 11 is a tire vulcanizing device, and this tire vulcanizing device 11 has a base 12 including a lower platen. A lower side mold 13 is fixed to the upper surface of the base 12, and the space between the lower side mold 13 and the base 12 is sealed by an O-ring 14 attached to the upper surface of the base 12 so as to be airtight. A molding recess 15 is formed on the upper surface of the lower side mold 13 to mold the lower sidewall portion S and bead portion B of the unvulcanized tire T. The base 12 and the lower side mold 13 described above constitute a lower base 16 as a whole. As a result, the lower base 16 has the lower side mold 13. Reference numeral 17 denotes an upper base installed above the lower base 16, and a piston rod of a vertical cylinder (not shown) is connected to the upper base 17. As a result, when the cylinder is operated, the upper base 17 moves up and down and moves away from and approaches the lower base 16.
[0011]
Reference numeral 20 denotes a relatively thin disk-shaped upper plate that is installed directly below the upper base 17 and functions as a part of the upper platen. The upper plate 20 extends vertically and is attached to the upper base 17. It is detachably attached to the piston rod 22 of the cylinder 21 while maintaining a coaxial relationship. As a result, when the cylinder 21 is operated, the piston rod 22 and the upper plate 20 can be lifted and lowered separately from the upper base 17. Here, the piston rod 22 extends in the vertical direction while penetrating the central portion of the upper base 17 and corresponds to a center shaft as a centering reference. An upper side mold 23 is fixed to the lower surface of the upper plate 20, and the space between the upper side mold 23 and the upper plate 20 is sealed by an O-ring 24 attached to the lower surface of the upper plate 20 so as to be airtight. . Further, a molding recess 25 is formed on the lower surface of the upper side mold 23 to mold the upper sidewall portion S and the bead portion B of the unvulcanized tire T. The above-described upper plate 20 and upper side mold 23 as a whole constitute a lifting body 26 that can be moved up and down between the lower base 16 and the upper base 17, and as a result, the lifting body 26 It will have a mold 23. Reference numeral 27 denotes an elevating body 26, more specifically, an outer ring installed on the outer side in the radial direction of the upper plate 20. The upper end of the outer ring 27 is fixed to the outer end of the upper base 17 in the radial direction by a plurality of bolts 27b. ing. The outer ring 27 is coaxial with the elevating body 26, and the inner diameter of the upper end thereof is substantially the same as the outer diameter of the upper plate 20. In addition, the outer ring 27 has an inclined surface 27a that is inclined radially inward as it goes upward on the inner periphery of the lower portion thereof. Reference numeral 29 denotes a relatively thin ring-shaped centering member whose outer periphery is in surface contact with the inner periphery of the upper end portion of the outer ring 27. The centering member 29 is coaxial with the piston rod 22 and functions as a part of the upper platen. . The centering member 29 is detachably attached to the outer ring 27 by sandwiching the outer end portion of the centering member 29 from both sides by the step formed on the outer ring 27 and the upper base 17. A ring portion 20a protruding upward is formed at the radially inner end of the upper plate 20, and the outer peripheral surface of the ring portion 20a constitutes a first cylindrical surface 20b coaxial with the piston rod 22. On the other hand, the centering member 29 has a second cylindrical surface 29a coaxial with the piston rod 22 (coaxial with the first cylindrical surface 20b) on the inner end in the radial direction, more specifically, on the inner periphery. The ring portion 20a is in surface contact with the first cylindrical surface 20b so as to be slidable by being inserted into the centering member 29. 28 is an O-ring attached to the outer periphery of the centering member 29, 30 is an O-ring as a second sealing means attached to the outer periphery of the upper end of the ring portion 20a, and these O-rings 28 and 30 are outer rings 27. And the centering member 29 and between the centering member 29 and the upper plate 20 are always sealed to prevent air flow therebetween.
[0012]
A sector mold 31 is disposed between the lower base 16 and the upper plate 20 and has a ring shape as a whole. The sector mold 31 is disposed on the radially inner side of the outer ring 27. The sector mold 31 is composed of a plurality of, for example, nine arc-shaped segments 32 divided in the circumferential direction. Each arc-shaped segment 32 is fixed to a slider 33 and a radially inner end of the slider 33, and is radially inward. The vulcanization segment 35 is formed on the side surface with a molding recess 34 in which the tread portion D of the unvulcanized tire T is molded. No vent hole (vent hole) is formed in the vulcanization segment 35. The upper ends of the sliders 33 of the arc-shaped segments 32 are supported so as to be movable in the radial direction on the lower surface of the elevating body 26, more specifically on the lower surface of the upper plate 20 radially outward from the upper side mold 23. When all the arc segments 32 move to the inner limit in the radial direction, the arc segments 32 are in close contact with each other to form a continuous ring-shaped sector mold 31. At this time, the sector mold 31 is the upper side mold of the descending end. 23 and the lower side mold 13 are in close contact with each other so that the upper and lower side and sector molds 32, 13, and 31 are closed to form a donut-shaped space in which the unvulcanized tire T is accommodated and a molding dent 25 , 15, and 34 constitute a molding surface that continuously defines the outer shape of the unvulcanized tire T. An inclined surface 33a having the same gradient as the inclined surface 27a of the outer ring 27 is formed on the outer periphery of each slider 33. The inclined surface 33a and the inclined surface 27a are slidable while being connected by a joint. Is engaged. As a result, when the outer ring 27 is lifted and lowered integrally with the upper base 17 and the centering member 29, each arc segment 32 of the sector mold 31 is supported by the lifting body 26 while being radiused by the wedge action of the inclined surfaces 27a and 33a. Move synchronously in the direction.
[0013]
Reference numeral 37 denotes a vertically extending cylindrical body that is loosely fitted in the central portion of the lower base 16, and this cylindrical body 37 is raised by a fluid cylinder or a knockout lever (not shown) when the vulcanized tire is taken out. A lower clamp ring 38 is attached to the outer periphery of the upper end of the cylindrical body 37. The lower clamp ring 38 is located between the upper and lower side molds 23 and 13, and when the cylindrical body 37 is lowered, the lower side mold 13 Abuts against the inner end of the. A center post 39 coaxial with the cylindrical body 37 is slidably inserted into the cylindrical body 37, and the center post 39 moves up and down separately from the cylindrical body 37 by a cylinder (not shown). An upper clamp ring 40 is attached to the outer periphery of the upper end of the center post 39. The upper clamp ring 40 is located between the upper side mold 23 and the lower clamp ring 38, and contacts the inner end of the upper side mold 23. You can touch. Reference numeral 41 denotes a bendable vulcanization bladder having a lower end portion sandwiched between the lower clamp ring 38 and an upper end portion of the upper clamp ring 40 in an airtight state, and the vulcanization medium 41 is injected into the vulcanization bladder 41. Then, the unvulcanized tire T expands into a donut shape, and vulcanizes while pressing the unvulcanized tire T against the mold surface of the closed vulcanization mold.
[0014]
  A seal plate 45 is fixed to the upper surface of the base 12 radially outward from the lower side mold 13. The seal plate 45 is in close contact with the upper surface of the base 12, and the radially outer side of the flange portion 45 a. The flange portion 45a and the base 12 are sealed by an O-ring 46 attached to the lower surface of the flange portion 45a so as to be airtight. The inner diameter of the cylindrical portion 45b is substantially the same as the outer diameter of the outer ring 27. As a result, when the outer ring 27 is lowered, the lower end portion of the outer ring 27 is inserted into the cylindrical portion 45b of the seal plate 45. Is done. 47 is an O-ring attached to the outer periphery of the lower end portion of the outer ring 27. The O-ring 47 is always connected to the outer ring 27 and the seal plate 45 while the outer ring 27 is between the position P and the lower limit N. Seal between. That is, the seal plate 45 and the O-ring 47 cooperate to seal between the outer ring 27 and the lower base 16 while the outer ring 27 is between the position P and the lower limit N. Here, the position P means a position away from the lower limit N of the outer ring 27 by a predetermined distance between 10 mm and 25 mm, and the position of the outer ring 27 during the descent immediately before the vulcanization mold is closed. It is. The lower limit N is the position of the outer ring 27 when the vulcanization mold is closed, and is the position when the outer ring 27 is lowered most. In this embodiment, the O-ring 47 and the seal plate 45 are moved from immediately before the outer ring 27 reaches the position P, that is, from when the outer ring 27 descends to just above the position P. The space between the outer ring 27 and the lower base 16 is sealed until reaching The seal plate 45 and O-ring 47 mentioned above as a wholeAThe water ring 27 reaches the position P 10-25 mm away from the lower limit NJust before reachingUntil the lower limit N is reached, a first sealing means 48 is configured to seal between the outer ring 27 and the lower base 16 and prevent the flow of air between them, and this first sealing means 48, in cooperation with the second sealing means (O-ring) 30 and third and fourth sealing means described later, the lower base 16, the outer ring 27, the lifting body 26, the upper and lower clamp rings 40, 38, A sealed space M is formed which is surrounded by the vulcanized bladder 41 and in which the unvulcanized tire T is accommodated.
[0015]
Reference numeral 50 denotes at least one penetrating exhaust hole formed at the lower end of the cylindrical portion 45b of the seal plate 45, and an exhaust mechanism (vacuum source) is connected to the exhaust hole 50 via a switching valve (not shown). Has been. The exhaust mechanism operates when the outer ring 27 has been lowered to the position P alone, and discharges the air in the sealed space M to the outside, thereby preventing adverse effects due to residual air. Here, when the outer ring 27 reaches the position P, that is, the outer ring 27 reaches a position away from the descending limit N by a predetermined distance between 10 mm and 25 mm, the air in the sealed space M is exhausted. The reason is that if the exhaust is performed when it is less than 10 mm, the interval between the vulcanization molds becomes too narrow and the exhaust is not smoothly performed, and the convex part on the inner surface of the sector mold 31 is an unvulcanized tire. This is because an independent space is created by biting into T, and that part cannot be exhausted. On the other hand, if the exhaust is performed when it exceeds 25 mm, the volume of the sealed space M becomes large and the exhaust is exhausted for a long time. This is because it is necessary. The exhaust hole 50 is provided at such a position even if the outer ring 27 is lowered to the lower limit N and the vulcanization mold is closed at this position. This is because the exhaust hole 50 is not closed by the mold 31 and the exhaust can be performed reliably. The exhaust hole 50 and the exhaust mechanism described above constitute an exhaust means 51 as a whole.
[0016]
54 is a plurality of lower narrow passages as third sealing means formed in the lower side mold 13 so as to be separated from each other in the circumferential direction, and one end of each of these lower narrow passages 54 is provided on the lower side of the unvulcanized tire T. It opens to the upper surface (molding recess 15) facing the bead portion B, and the other end is not covered by another vulcanization mold when the vulcanization mold is closed (in other words, exposed to the sealed space during exhaustion described later). Open) on the outer surface. Reference numeral 55 denotes a plurality of upper narrow passages as fourth seal means formed in the upper side mold 23 so as to be separated from each other in the circumferential direction. One end of each of these upper narrow passages 55 is a bead on the upper side of the unvulcanized tire T. It opens to the lower surface (molding recess 25) facing part B, and the other end is not covered with another vulcanization mold when the vulcanization mold is closed (in other words, exposed to the sealed space during exhaustion described later). ) Open on the outer surface. In addition, the diameters of the lower narrow passages 54 and 55 are about 0.6 to 0.9 mm. Here, the upper and lower small diameter passages 55 and 54 are open at one end, and the molding recesses 25 and 15 of the lower side molds 23 and 13 are lowered to the position P as described above. At this time, since the air in the sealed space M is exhausted by the exhaust means 51 at this time, the upper and lower narrow diameter passages 55 and 54 are substantially in surface contact with the bead portion B of the unvulcanized tire T. The air remaining between the upper and lower bead portions B and the upper and lower side molds 23 and 13 is guided to the sealed space M near the exhaust hole 50, and one end opening adsorbs these bead portions B. Then, sealing between the upper and lower side molds 23 and 13 and the unvulcanized tire T is performed at the position, and between the upper side mold 23 and the upper clamp ring 40 and between the lower side mold 13 and the lower clamp ring 38. Each air flow is blocked. Accordingly, a sealing means for preventing air from entering between the upper and lower side molds 23 and 13 and the bead portion B of the unvulcanized tire T, for example, between the upper side mold 23 and the upper clamp ring 40 is interposed. It is possible to omit the O-ring to be mounted and the O-ring interposed between the lower side mold 13 and the lower clamp ring 38.
[0017]
Next, the operation of one embodiment of the present invention will be described.
When vulcanizing the unvulcanized tire T, first, the unvulcanized tire T is loaded into the tire vulcanizer 11 and fitted to the outside of the cylindrical vulcanization bladder 41, and the lower side The sidewall portion S and the bead portion B are brought into contact with the molding recess 15 of the lower side mold 13. Next, while lowering the center post 39 and the upper clamp ring 40, a fluid is supplied into the vulcanizing bladder 41 to inflate the vulcanizing bladder 41 into a donut shape and enter the unvulcanized tire T.
[0018]
Next, the upper base 17, the outer ring 27, the centering member 29 and the upper plate 20, the upper side, and the sector molds 23 and 31 are lowered together, and the upper side mold 23 is brought close to the unvulcanized tire T. In the middle of the lowering, the upper side mold 23 reaches its lower end, and the lower end of the sector mold 31, more specifically, the lower end of the slider 33 is brought into contact with the upper surface of the lower base 16 via the flange portion 45a of the seal plate 45. When the upper side mold 23 comes into contact with the upper clamp ring 40, the upper side and the sector molds 23 and 31 descend. At this time, the upper side mold 23 is located in the very vicinity of the unvulcanized tire T, there is almost no gap between the molding dent 25 and the upper side wall part S, and the bead part B is almost surface. In contact.
[0019]
In this way, the upper side and sector molds 23 and 31 stop descending, but the upper base 17 and the outer ring 27 continue to descend independently thereafter. As a result, each arc segment 32 of the sector mold 31 is pushed by the wedge action of the inclined surfaces 27a, 33a while being supported by the elevating body 26, and moves inward in the radial direction to approach the unvulcanized tire T. At this time, since the ring portion 20a is inserted into the centering member 29 and the distance between the upper base 17 and the lift 26 is reduced, the piston rod 22 of the cylinder 21 is retracted following the lowering of the upper base 17. When the outer ring 27 is lowered while being engaged with each arc segment 32 of the sector mold 31 in this way, the outer ring 27 connected to the upper base 17 is wobbled by the reaction force from the sector mold 31 only at the upper end. However, as described above, the centering member 29 whose outer periphery is in surface contact with the inner periphery of the upper end of the outer ring 27 is provided, and the piston rod 22 serving as a centering reference is provided on the second cylindrical surface 29a provided on the centering member 29. Since the first cylindrical surface 20b of the upper plate 20 attached to the surface is brought into surface contact, the wobbling of the outer ring 27 is firmly regulated by the piston rod 22 through the upper plate 20 and the centering member 29, Such wobble as described above is effectively suppressed. When the outer ring 27 enters the cylindrical portion 45 b of the seal plate 45 and descends to a position just above the position P, the O-ring 47 and the seal plate 45 are located between the outer ring 27 and the lower base 16. Sealing is started, and the sealing is performed thereafter until the outer ring 27 reaches the lowering limit N. Thereby, a sealed space M surrounded by the lower base 16, the outer ring 27, the elevating body 26, the upper and lower clamp rings 40 and 38, and the vulcanization bladder 41 is formed.
[0020]
  Then, when the outer ring 27 is lowered to the position P as shown in FIG. 1, the lowering of the upper base 17 and the outer ring 27 is temporarily stopped, and the exhaust mechanism is operated to close the inside of the sealed space M. Air is discharged to the outside through the exhaust hole 50, and the sealed space M is set to a predetermined degree of vacuum. Here, the sealed space M where the exhaust is performed is surrounded by the lower base 16, the outer ring 27, the centering member 29, the upper plate 20, the upper side mold 23, the upper and lower clamp rings 40 and 38, and the vulcanization bladder 41. The lower side mold 13 and the unvulcanized tire T are in close contact with each other, and there is almost no gap between the upper side mold 23 and the unvulcanized tire T as described above. Furthermore, a slight gap between the sector mold 31 and the unvulcanized tire T, that is, the outer ring 27 is located at the position P.Just beforeSince there is only a distance that the sector mold 31 is pushed and moved while moving from the lower limit N to the lower limit N, the volume of the space to be evacuated is reduced, and as a result, the evacuation time until a predetermined degree of vacuum is achieved. Is shortened and productivity is improved. Moreover, since there is almost no gap between the vulcanized mold and the unvulcanized tire T as described above, growth and deformation (particularly deformation in the width direction) of the unvulcanized tire T during exhaust are limited. This prevents the situation where the unvulcanized tire T is peeled off from the vulcanized bladder 41 or a part of the unvulcanized tire T is caught between the vulcanized molds. Will improve. In addition, during the above-described exhaust, the upper and lower narrow passages 55 and 54 allow the air remaining between the upper and lower bead portions B and the upper and lower side molds 23 and 13 to be in the vicinity of the exhaust hole 50. The one end opening adsorbs the bead portions B and seals between the upper and lower side molds 23 and 13 and the unvulcanized tire T. As a result, peeling and deformation of the unvulcanized tire T from the vulcanized bladder 41 are further restricted, and the fitting between the vulcanized bladder 41 and the unvulcanized tire T is maintained well, and the quality of the product tire is improved. Further improve. Usually, the sealed space M is reduced to an absolute pressure of 6600 Pa or less by exhausting for 20 seconds or less. Here, the reason why the degree of vacuum of the sealed space M is set to 6600 Pa or less is to suppress a tire appearance defect due to traces of residual air within the standard. In order to reliably suppress the traces as described above, it is preferable to reduce the absolute pressure to 1300 Pa or less by exhausting for 15 seconds or less.
[0021]
When exhaust is completed in this manner, the upper base 17 and the outer ring 27 are lowered again. When the outer ring 27 reaches the lowering limit N, as shown in FIG. 2, the sector mold 31 reaches the radially inner limit, and the upper and lower sides, the sector molds 23, 13, and 31 are closed. Thereafter, a high-temperature and high-pressure vulcanizing medium is supplied into the vulcanizing bladder 41, and the unvulcanized tire T is pressed against the molding recesses 25, 15, and 34 of the upper and lower sides and the sector molds 23, 13, and 31 to be molded. While being vulcanized. Further, as described above, the first cylindrical surface 20b is provided on the upper plate 20 attached to the piston rod 22 serving as a centering reference, and the second cylindrical surface 29a and the outer ring 27 are in surface contact with the first cylindrical surface 20b. Since the centering member 29 having an outer periphery that is in surface contact with the inner periphery of the upper end portion is provided, the position of the outer ring 27 is regulated by the first cylindrical surface 20b and the centering member 29, so that the outer ring 27 is highly accurate. 27 assembly accuracy, especially centering accuracy is high. Here, since the centering accuracy becomes higher as the sliding surfaces of the two members are radially inward, the first and second cylindrical surfaces 20b and 29a are both connected to the upper plate 20 and the centering member 29. The centering accuracy is improved by providing it at the radially inner end. Although the centering member 29 may be integrally formed with the outer ring 27, in this way, even if the upper plate 20 is removed at the time of mold replacement, the centering member becomes an obstacle and it is difficult to carry in and out the mold. Become. For this reason, the integral formation as described above should be avoided.
[0022]
In the above-described embodiment, the seal plate 45 is attached to the base 12. However, in the present invention, the seal plate 45 may be attached to the lower side mold 13. In the above-described embodiment, the upper base 17 and the outer ring 27 are exhausted from the sealed space M in a state where the lowering of the upper base 17 and the outer ring 27 is temporarily stopped. You may make it exhaust while lowering 27. Furthermore, in the above-described embodiment, both the upper plate 20 and the centering member 29 function as a platen. However, in the present invention, the upper base 17 has a function as a platen taken up from the upper plate 20 and the centering member 29. You may make it let. In the above-described embodiment, the upper plate 20 is provided with the ring portion 20a, the first cylindrical surface 20b is formed on the outer periphery of the ring portion 20a, and the second cylindrical surface 29a is formed on the inner periphery of the centering member 29. However, in the present invention, a ring portion is provided in the centering member, a ring groove into which the ring portion is inserted is formed on the upper surface of the upper plate, and the first cylindrical surface is formed on the outer surface of the ring groove. The second cylindrical surface may be formed on the outer peripheral surface of the ring portion.
[0023]
【The invention's effect】
As described above, according to the present invention, the exhaust time can be shortened and the quality of the product tire can be improved.
[Brief description of the drawings]
FIG. 1 is a partially cutaway front sectional view showing an embodiment of the present invention.
FIG. 2 is a front sectional view similar to FIG. 1 when the vulcanization mold is closed.
[Explanation of symbols]
    11 ... Tire vulcanizer 13 ... Lower side mold
  16 ... Lower base 17 ... Upper base
  20 ... Upper plate 20b ... First cylindrical surface
22 ... Center shaft 23 ... Upper side mold
26 ... Elevator 27 ... Outer ring
27a ... Inclined surface 29 ... Centering member
    29a ... Second cylindrical surface 31 ... Sector mold
    48… Sealing means 51… Exhaust means
    54, 55 ... Narrow passage T ... Unvulcanized tire
B ... Bead part M ... Sealed space

Claims (6)

After the upper side mold is lowered together with the outer ring to the lower end of the upper side mold, the outer ring is lowered alone to the lower limit N of the outer ring, and the sector mold is radiused by the wedge action of the inclined surface of the outer ring. In the tire vulcanization method in which the vulcanized mold is closed by moving to the inner limit in the direction, and then the unvulcanized tire in the vulcanized mold is vulcanized , The space in which the unvulcanized tire is accommodated is sealed by the sealing means from just before the ring reaches the position P 10 to 25 mm away from the lower limit N until it reaches the lower limit N, and the outer ring The tire vulcanizing method is characterized in that air in the sealed space is exhausted to the outside when the air travels down to the position P. A lower base with a lower side mold, installed above the lower base, can be moved up and down between the lower base and the upper base by separating and approaching the lower base by moving up and down Elevating body installed and having an upper side mold, and installed on the outer side in the radial direction of the elevating body, with the upper end fixed to the upper base and an inclined surface inclined inward in the radial direction toward the upper side on the inner circumference An outer ring, and a sector mold that is supported on the lower surface of the lifting body so as to be movable in the radial direction, and that can move in the radial direction by the wedge action of the inclined surface of the outer ring when the outer ring and the upper base are lifted and lowered. The upper side and the sector mold are lowered to the lower end of the upper side mold where the sector mold contacts the lower base together with the upper ring and the outer ring, and then the upper base and the outer ring are Is lowered to the lower limit N of the outer ring, and the sector mold is moved to the radially inner limit by the wedge action of the inclined surface of the outer ring to close the vulcanization mold. In a tire vulcanizing apparatus adapted to vulcanize a vulcanized tire, when the outer ring is lowered alone, the outer ring reaches the lower limit N immediately before it reaches the position P that is 10-25 mm away from the lower limit N. In the meantime, when providing the sealing means for sealing between the outer ring and the lower base to form a sealed space in which the unvulcanized tire is accommodated, and when the outer ring is lowered to the position P, A tire vulcanizing apparatus comprising exhaust means for exhausting air in the sealed space to the outside.     In the upper and lower side molds, small diameter passages are formed, one end of which faces the bead portion of the unvulcanized tire, the lower surface opens on the upper surface, and the other end opens on the outer surface exposed to the sealed space during exhaust. The seal between the lower side mold and the unvulcanized tire is performed by adsorbing each bead portion of the unvulcanized tire by one end opening of these narrow passages during exhaust. Tire vulcanizer.     A disc-shaped upper plate that extends in the vertical direction while penetrating the upper base and is provided with a center shaft that can be raised and lowered as a centering reference and that is mounted on the center shaft and is located directly below the upper base. And an upper side mold fixed to the lower surface of the upper plate, and is attached to the outer ring. The outer periphery is in surface contact with the inner periphery of the upper end of the outer ring, and between the upper base and the upper plate. A ring-shaped centering member disposed on the upper plate, a first cylindrical surface coaxial with the center shaft provided at the radially inner end of the upper plate, and a center shaft provided at the radially inner end of the centering member; The tire vulcanizing apparatus according to claim 2, wherein the second cylindrical surface of the coaxial is slidably brought into surface contact.     The tire vulcanizer according to any one of claims 2 to 4, wherein the absolute pressure in the sealed space is reduced to 6600 Pa or less by the exhaust means.     The tire vulcanizing apparatus according to claim 4, wherein the centering member is detachably attached to the outer ring.

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