JP2017087613A - Tire production method and tire molding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly close a die without damaging the same.SOLUTION: The first step where the inside of a tire vulcanization die 2 having an upper die, a lower die 22 and a sector 20 is disposed with a green tire GT in such a manner that the axial direction goes vertically, and the inside face is held with a bladder 13, the second step where, while heating the green tire GT, the upper die 21 and the sector 20 are lowered, and a die 2 for tire vulcanization is closed, and the third step where the die 2 for tire vulcanization is closed are practiced. The lowering operations of the upper die 21 and the sector 20 in the second step are performed by the first lowering operation of performing lowering at the first lowering speed and the second lowering operation of performing the second lowering speed at a speed lower than the first lowering speed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tire manufacturing method and a tire molding apparatus.

Patent Document 1 discloses that the mold closing operation is temporarily stopped for 2 to 5 seconds until the distance between the joint surface of the segment mold and the joint surface of the side mold becomes zero. ing.
In Patent Document 2, each of the upper and lower side molds is gradually moved closer to the raw tire while maintaining the relative distance to the surface of the raw tire arranged at the middle position between them to close the mold of the vulcanization mold. The point which was made to perform is disclosed.
Patent Document 3 discloses that the convex portion of the sector mold and the convex strip portion of the side wall mold are pushed in the vicinity of the buttress portion of the split surface when both molds are closed.

  However, none of the above-mentioned patent documents considers the moving speed of the mold until the mold is closed. If the moving speed immediately before the mold closes is large, the mold may be damaged by the collision between the molds. On the other hand, when the speed at which the mold closes is slowed down, the molding time becomes longer and the rubber may be denatured.

JP 2013-1111859 A JP 2008-290334 A JP-A-8-216620

  This invention makes it a subject to provide the tire manufacturing method and tire molding apparatus which can be closed smoothly, without damaging a metal mold | die.

As a means for solving the above problems, the present invention provides:
A first step of placing a green tire in a tire vulcanization mold having an upper mold, a lower mold and a sector so that an axial direction is directed vertically and holding an inner surface with a bladder;
A second step of closing the tire vulcanization mold by lowering the upper mold and the sector while heating the green tire;
A third step of clamping the tire vulcanization mold;
A tire manufacturing method for performing
A lowering operation of lowering the upper mold and the sector in the second step at a first lowering speed and a second lowering operation of lowering at a second lowering speed lower than the first lowering speed; A tire manufacturing method is provided.

  According to this, even when the sector descends due to the second descending operation, the speed at which it contacts the lower part of the tire vulcanizing mold can be reduced to the second descending speed. Therefore, it is possible to prevent the sector or the like from being damaged by the impact force caused by the contact. In addition, the sector can be lowered by the first descent operation that descends at the first descent speed until the second descent operation is reached, so that the cycle time becomes longer or the green tire is overheated and the vulcanized state is reached. There will be no inconvenience.

  It is preferable to execute an intermediate stop operation for temporarily stopping the lower die and the sector lowering operation before the transition from the first lowering operation to the second lowering operation.

  According to this, switching from the first descending speed to the second descending speed can be surely performed with sharpness.

  The stop position of the upper mold and the sector is such that the distance l from the upper surface of the green tire to the lower end of the sector is 1/2 L when the width dimension in the axial direction of the green tire held by the bladder is L. It is preferable to satisfy <l <3 / 4L.

  The stop time of the intermediate stop operation is preferably 2 seconds or less.

  The second descending speed is preferably 30% or more and 80% or less of the first descending speed.

  Immediately before the tire vulcanization mold is completely closed, it is preferable to execute a stop operation immediately before stopping the movement of the sector toward the inner diameter side.

  According to this, even if the sector is displaced from an appropriate position when moving to the inner diameter side, it can be corrected by the immediately preceding stop operation. Therefore, it is possible to prevent the green tire from being caught in the circumferential gap of the sector.

  The stop time of the immediately preceding stop operation is preferably 2 seconds or less.

  The immediately preceding stop operation is preferably performed in a range where a gap between sectors arranged in parallel in the circumferential direction is 20 mm or less.

As a means for solving the above problems, the present invention provides:
An upper mold, a lower mold and a sector forming the outer surface of the green tire;
A bladder that supports the inner surface of the green tire;
Driving means for lowering the upper mold and the sector;
Drive control of the drive means to cause the lowering movement of the upper mold and the sector to descend at a first lowering speed at least at a first lowering speed and a second lowering speed that is lower than the first lowering speed. Control means for performing the second descent operation;
A tire molding apparatus is provided.

  According to the present invention, since the lowering speed of the upper mold and the sector when closing the mold is slowed in the middle, it is possible to prevent the molds from colliding with each other and causing damage.

It is a front half section view showing a part of a vulcanization molding machine equipped with a tire vulcanization mold concerning this embodiment. FIG. 2 is a front half sectional view showing a clamping operation of the tire vulcanizing mold in FIG. 1. FIG. 2 is a plan view of a pair of sectors adjacent in the circumferential direction among the sectors shown in FIG. 1. It is a block diagram of the vulcanization molding machine of FIG. It is a flowchart which shows the drive control by the control apparatus of FIG. It is a graph which shows the descent speed of the upper mold | type and a sector with the vulcanization molding machine of FIG. It is a graph which shows the descent speed of the upper model and sector concerning other embodiments. It is a graph which shows the descent speed of the upper model and sector concerning other embodiments. It is a graph which shows the descent speed of the upper model and sector concerning other embodiments.

  Embodiments according to the present invention will be described below with reference to the accompanying drawings. In addition, the following description is only illustrations essentially and does not intend restrict | limiting this invention, its application thing, or its use. Further, the drawings are schematic, and the ratio of each dimension is different from the actual one.

  FIG. 1 shows a state in which a tire vulcanizing mold 2 according to this embodiment is mounted on a vulcanization molding machine 1. A tire vulcanization mold 2 is attached via a container 6 between an upper plate 3 and an upper platen 4 of the vulcanization molding machine 1 and a lower platen 5.

  The upper plate 3 is fixed to the lower end portion of the elevating cylinder 7. A lifting rod 8 is arranged at the center of the lifting cylinder 7. The upper platen 4 is fixed to the lower end portion of the elevating rod 8. The raising / lowering cylinder 7 and the raising / lowering rod 8 are raised / lowered by the drive device 25 (refer FIG. 4). The upper plate 3 and the upper platen 4 are configured to be movable up and down independently. The drive device 25 is driven and controlled by a control device 26 (see FIG. 4), and moves the upper plate 3 and the upper platen 4 up and down independently to stop them. A flow path 4a is formed in the upper platen 4 so that the temperature can be adjusted by flowing a heat exchange medium (for example, oil).

  Similarly to the upper platen 4, the lower platen 5 is formed with a flow path 5 a through which the heat exchange medium flows. Then, by adjusting the temperature of the heat exchange medium, the tire vulcanization mold 2 can be brought to a desired vulcanization temperature via the upper platen 4 and the lower platen 5. A bladder unit 9 is disposed at the center of the lower platen 5.

  The bladder unit 9 is obtained by attaching a bladder 13 to an upper clamp 11 and a lower clamp 12 fixed to a support shaft 10 that can be moved up and down. In the space surrounded by the upper clamp 11, the lower clamp 12 and the bladder 13, air is supplied and discharged by a supply / exhaust device (not shown). The bladder 13 is supplied with air and swells to the outer peripheral side, and supports the green tire GT from the inside.

  The container 6 includes a segment 14, a jacket ring 15, an upper container plate 16, and a lower container plate 17.

  The segment 14 is composed of a plurality (in this case, nine pieces) for screwing each sector 20 of the tire vulcanizing mold 2 described later. The inner surface of each segment 14 extends along the outer surface of the sector 20, and the outer surface is formed of an inclined surface (outer peripheral conical surface) that gradually expands toward the outer diameter side as it goes downward. Each segment 14 is supported on the upper slide 18 so as to be capable of reciprocating in the radial direction.

  The jacket ring 15 has a hollow cylindrical shape, and its upper end surface is fixed to the upper plate 3. And it raises / lowers according to the raising / lowering operation of the raising / lowering cylinder 7. The inner surface of the jacket ring 15 is composed of an inner circumferential conical surface that gradually inclines toward the outer diameter side toward the lower end side. The inner peripheral side conical surface of the jacket ring 15 and the outer peripheral side conical surface of each segment 14 slide along the conical surface and are not separated from each other (for example, by a configuration like a tenon and a dovetail). Yes. As a result, when the jacket ring 15 is lowered, the outer circumferential side conical surface of each segment 14 is pressed by the inner circumferential side conical surface thereof, and the segment 14 in a state of spreading to the outer diameter side is connected annularly on the inner diameter side. It can be moved to the state.

  The upper container plate 16 has an upper slide 18 fixed to the outer peripheral side lower surface, and an upper mold 21 to be described later fixed to the inner peripheral lower surface. The upper container plate itself is fixed to the lower surface of the upper platen 4. Thus, when the lifting rod 8 moves up and down, the upper mold 21 and the segment 14 (including the sector 20 fixed to the segment 14) move up and down together with the upper platen 4 and the upper container plate 16.

  The lower container plate 17 has a lower slide 19 fixed to the outer peripheral upper surface and a lower mold 22 to be described later fixed to the inner peripheral upper surface. The segment 14 is placed on the lower slide 19 when the mold is clamped, and is supported so as to be slidable in the radial direction. The lower container plate 17 itself is fixed to the upper surface of the lower platen 5.

  The tire vulcanizing mold 2 includes a sector 20, an upper mold 21, and a lower mold 22.

  The sector 20 is made of an aluminum alloy, is divided into a plurality of pieces in the tire circumferential direction (here, 9 divisions), and continues in an annular shape while moving to the inner diameter side. Each sector 20 is configured with a tread molding surface for molding a tread portion of the tire on the inner surface.

  The upper mold | type 21 is formed in cyclic | annular form, and the upper bead ring 23 is being fixed to the inner peripheral part. The upper mold 21 is fixed to the upper container plate 16 and moves up and down as the lifting rod 8 moves up and down. When descending, the bead portion of the green tire GT can be pressed by the upper bead ring 23. Thereby, the sidewall portion and the bead portion of the tire are formed by the lower inner surface of the upper die 21 and the lower surface of the upper bead ring 23.

  The lower die 22 is formed in a ring shape like the upper die 21, and a lower bead ring 24 is fixed to the inner peripheral portion.

  In the vulcanization molding machine 1 equipped with the tire vulcanization mold 2 having the above-described configuration, the green tire GT is set as follows, and the mold is closed according to the flowchart of FIG. Thus, vulcanization molding of the green tire GT is performed.

  That is, in the mold open state shown in FIG. 2A, the green tire GT is placed on the lower mold 22 so that the axial direction of the green tire GT is directed vertically. At this time, the bead portion positioned on the lower side is positioned on the lower bead ring 24.

  Then, as shown in FIG. 2B, air is supplied into the bladder 13 to be inflated, and the inner surface of the green tire GT is held by the outer surface (step S1). Thereby, the green tire GT is supported by the lower bead ring 24 and the bladder 13 and is not in contact with the lower mold 22.

  Subsequently, by driving the driving device 25, the upper die 21 and the sector 20 are lowered by the elevating rod 8 and the elevating cylinder 7 (step S2). At this time, the lowering operation of the upper die 21 and the sector 20 includes a first lowering operation (step S2-1) for lowering at the first lowering speed, an intermediate stop operation (step S2-2) for temporarily stopping, and a first lowering operation. The second descent operation (step S2-3) is performed to descend at a second descent speed that is lower than the speed. The change in speed in each operation is shown in the graph of FIG.

  In the first lowering operation, the lowering speeds of the upper mold 21 and the sector 20 may be set to the same standard speed as in the prior art. Specifically, the descending speed from the start of the lowering of the upper mold 21 and the sector 20 to the closing of the mold may be set to 0.3 m / s to 2.0 m / s. However, since the intermediate stop operation and the second descent operation described below are executed, the speed can be set faster than this speed range.

  In the intermediate stop operation, as shown in FIG. 2B, when the width dimension in the axial direction of the green tire GT held by the bladder 13 is L, the upper end (bead part) of the green tire GT The lowering operation of the upper mold 21 is temporarily stopped at a stop position where the distance l to the lower end satisfies l ≦ 3 / 4L, preferably l ≦ 1 / 2L. By setting the stop position in this way, it is possible to prevent the sector 20 from colliding with the lower slide 19 at the first descending speed. Further, the stop time is set to 2 seconds or less so that the green tire GT is not vulcanized before vulcanization molding due to the mold temperature.

  In the second lowering operation, the lowering speed of the upper mold 21 and the sector 20 is set to a second lowering speed that is lower than the first lowering speed (standard speed). The second descending speed is 30% or more and 80% or less of the first descending speed. If the second descending speed is less than 30% of the first descending speed, it takes too much time to close the mold, and the green tire GT is vulcanized before mold clamping. On the other hand, if the second descending speed exceeds 80% of the first descending speed, the speed at which the sector 20 contacts the lower slide 19 cannot be sufficiently suppressed, which may cause damage. However, when the first descent speed of the first descent operation is set faster than the standard speed, the lower limit value (30%) and the lower limit value (80%) of the second descent speed need to be changed to a smaller ratio.

  During the second lowering operation, as shown in FIG. 2C, the upper bead ring 23 comes into contact with the bead portion located on the upper side of the green tire GT. Then, as shown in FIG. 2D, after the green tire GT is deformed via the bead portion, the upper mold 21 comes into contact with the green tire GT. When the upper mold 21 is lowered to the clamping completion position, the green tire GT is sandwiched between the upper mold 21 and the lower mold 22 as shown in FIG.

  Even after the upper die 21 is lowered to the clamping completion position, the lowering by the elevating cylinder 7 is continued, and the jacket ring 15 is moved downward together with the upper plate 3. Thereby, the inner peripheral conical surface of the jacket ring 15 presses the outer peripheral conical surface of the segment 14. Then, the sector 20 fixed to the segment 14 moves to the inner diameter side.

  When the gap g between the sectors 20 arranged side by side in the circumferential direction becomes 20 mm or less (step S3), a stop operation immediately before stopping the descent by the elevating cylinder 7 is executed (step S4). As shown in FIG. 2E, whether the gap between the sectors 20 is 20 mm or less is from the lower end position of the segment 14 to the lower end position of the jacket ring 15 when the height dimension of the segment 14 is H. The distance h is determined by whether or not 3 / 4H ≧ h ≧ 1 / 2H is satisfied. Note that the relationship between the descending dimension by the elevating cylinder 7 and the gap between the sectors 20 may be recorded in advance, and the determination may be made based on the result.

  FIG. 3 shows a state in which some of the sectors 20 are moving to the inner diameter side. The sector 20 may be misaligned during movement, as indicated by a two-dot chain line in FIG. At this time, the gap between the two sectors 20 shown in the drawing becomes wider on the inner diameter side and becomes smaller toward the outer diameter side. For this reason, when the sector 20 moves to the inner diameter side in this posture, the green tire GT is easily caught in the gap. By executing the immediately preceding stop operation, the sector 20 is corrected for the positional deviation from the proper position by the elastic force of the green tire GT.

  In the last stop operation, the green tire GT is vulcanized before the mold clamping is performed because the stop time exceeds 2 seconds. Therefore, the stop time is set to 2 seconds or less (step S5).

  Therefore, if the movement of the sector 20 is resumed (step S6), all the sectors 20 can be moved uniformly toward the inner diameter side while eliminating the rubber bite between the sectors 20. Further, the green tire GT is not vulcanized before mold clamping.

  Thereafter, when the upper plate 3 comes into contact with the upper platen 4 (step S7), the lowering by the elevating cylinder 7 is stopped (step S8). Thereby, as shown in FIG. 2F, the green tire GT is pressed by the upper mold 21, the lower mold 22, and the sector 20 on the outer side and the bladder 13 on the inner side. In the upper platen 4 and the lower platen 5, a heat exchange medium whose temperature is adjusted so that the green tire GT can be vulcanized at a predetermined vulcanization temperature is always flowing (regardless of whether the mold is open or clamped). doing. As a result, the green tire GT is vulcanized and the tire is completed. The finished tire is removed by opening the mold.

  As described above, according to the vulcanization molding of the green tire GT by the vulcanization molding machine 1, the upper die 21 and the sector 20 are first lowered by the first lowering operation, the intermediate stopping operation, and the second lowering operation. ing. In the second lowering operation, the speed when the sector 20 contacts the lower slide 19 is set to a sufficiently lowered second lowering speed. Therefore, even if the sector 20 comes into contact with the lower slide 19, a large impact force does not act, and the damage can be prevented. Further, when the sector 20 is moved to the inner diameter side by mold clamping, the sector 20 is temporarily stopped at the point of time after the gap between the sectors 20 becomes 20 mm or less until it comes into contact. Therefore, the position of each sector 20 can be corrected to an appropriate position to prevent the green tire GT from being caught between the sectors 20.

  In addition, this invention is not limited to the structure described in the said embodiment, A various change is possible.

  In the above embodiment, the intermediate stop operation is executed between the first lowering operation and the second lowering operation. However, this intermediate stop operation is not always necessary, and the sector 20 is in contact with the lower slide 19. It is sufficient if the speed of the second speed is the second descending speed. For example, as shown in FIG. 7, the second descent operation may be executed after the first descent operation without executing the intermediate stop operation. Also, as shown in FIG. 8, the second descent speed of the second descent operation can be set to be gradually slower than the constant speed. However, by sandwiching the intermediate stop operation, the operation can be ensured and the sector 20 can be accurately lowered at the second descending speed. Furthermore, as shown in FIG. 9, a deceleration operation for gradually decreasing the speed from the first descending speed toward the second descending speed can be executed instead of the intermediate stop operation.

  In the above-described embodiment, the descent speed of the sector 20 is changed in two steps, the first descent operation and the second descent operation. However, the present invention is not limited to this. The speed can also be changed (decreased).

DESCRIPTION OF SYMBOLS 1 ... Vulcanizing molding machine 2 ... Mold for tire vulcanization 3 ... Upper plate 4 ... Upper platen 5 ... Lower platen 6 ... Container 7 ... Lifting cylinder 8 ... Lifting rod 9 ... Bladder unit 10 ... Spindle 11 ... Upper clamp 12 ... Lower clamp 13 ... Bladder 14 ... Segment 15 ... Jacket ring 16 ... Upper container plate 17 ... Lower container plate 18 ... Upper slide 19 ... Lower slide 20 ... Sector 21 ... Upper mold 22 ... Lower mold 23 ... Upper bead ring 24 ... Lower Bead ring GT ... Green tires

Claims (9)

A first step of placing a green tire in a tire vulcanization mold having an upper mold, a lower mold and a sector so that an axial direction is directed vertically and holding an inner surface with a bladder;
A second step of closing the tire vulcanization mold by lowering the upper mold and the sector while heating the green tire;
A third step of clamping the tire vulcanization mold;
A tire manufacturing method for performing
A lowering operation of lowering the upper mold and the sector in the second step at a first lowering speed and a second lowering operation of lowering at a second lowering speed lower than the first lowering speed; The tire manufacturing method characterized by performing by.   2. The tire manufacturing method according to claim 1, wherein an intermediate stop operation for temporarily stopping a lowering operation of the upper mold and the sector is executed before shifting from the first lowering operation to the second lowering operation.   The stop position of the upper mold and the sector is such that the distance l from the upper surface of the green tire to the lower end of the sector is 1/2 L when the width dimension in the axial direction of the green tire held by the bladder is L. <1 <3 / 4L is satisfied, The tire manufacturing method of Claim 2 characterized by the above-mentioned.   The tire manufacturing method according to claim 2 or 3, wherein a stop time of the intermediate stop operation is 2 seconds or less.   5. The tire manufacturing method according to claim 1, wherein the second descending speed is not less than 30% and not more than 80% of the first descending speed. 6.   6. The stop operation immediately before stopping the movement operation toward the inner diameter side of the sector is performed immediately before the tire vulcanization mold is completely closed. 6. Tire manufacturing method.   The tire manufacturing method according to claim 6, wherein a stop time of the immediately preceding stop operation is 2 seconds or less.   The tire manufacturing method according to claim 6 or 7, wherein the immediately preceding stop operation is performed in a range where a gap between sectors arranged side by side in the circumferential direction is 20 mm or less. An upper mold, a lower mold and a sector forming the outer surface of the green tire;
A bladder that supports the inner surface of the green tire;
Driving means for lowering the upper mold and the sector;
Drive control of the drive means to cause the lowering movement of the upper mold and the sector to descend at a first lowering speed at least at a first lowering speed and a second lowering speed that is lower than the first lowering speed. Control means for performing the second descent operation;
A tire molding apparatus comprising:

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