JP4513306B2 - Tire vulcanizer - Google Patents

Description

  The present invention relates to a tire vulcanizer having a split-type mold, and more particularly to a tire vulcanizer that reduces block chipping that occurs in a tire tread portion during mold release.

  Conventionally, tire vulcanizers having a split mold have been widely used. This type of tire vulcanizer includes a pair of bead rings that contact a bead portion of a tire inserted into a mold, and the mold is released while the bead portion of the tire is sandwiched between these bead rings. (For example, refer to Patent Document 1).

However, after removing one mold from the tire, when removing the tire from the other mold by moving the bead ring in the tire axial direction, the main groove forming bone of the mold is caught on the tire tread portion, and the block chipping May occur. Conventionally, this has been dealt with by increasing the angle of the main groove wall of the mold, changing the cap rubber, or applying a release agent such as silicone on the inner surface of the mold, but this will change the tire performance. There is an inconvenience that the number of work steps increases. Therefore, it is desired to improve the releasability of the tire without causing these disadvantages.
JP-A-8-25360

  An object of the present invention is to provide a tire vulcanizer that can reduce block chipping generated in a tire tread portion at the time of mold release.

The tire vulcanizer according to the present invention for solving the above-described object is a tire vulcanizer including a bead ring that abuts against a bead portion of a tire inserted into a split mold. An arc-shaped segment piece obtained by dividing a part of the arc-shaped segment piece and an annular segment piece excluding the arc-shaped segment piece so that the annular segment piece is selectively moved in the tire axial direction. It is characterized by comprising.

According to the present invention, constituted by a part of the outer circumferential side metal mold bead ring and arcuate split pieces obtained by dividing the circumferential direction, and the divided pieces of circular except for the arc-shaped split pieces, the annular Since the divided pieces are selectively moved in the tire axial direction, only a part of the circumference of the vulcanized tire can be selectively lifted. Therefore, at the time of mold release, force is not applied evenly around the main groove forming bone formed on the inner surface of the mold, and the force applied to the tire tread portion when removing the tire from the mold is reduced, and block breakage is prevented. Can be reduced. In addition, unlike conventional block chipping measures, there is no inconvenience that the tire performance is changed or the number of work steps is increased.

In the present invention, the arc-shaped segment piece and the annular segment piece may be configured to move in the tire axial direction with a phase difference. Moreover, it is preferable to provide the cyclic | annular division | segmentation piece which moves previously in a bead ring and lifts a bead part in the range of 90 degrees-270 degrees around a ring axis | shaft. By defining such a range, block chipping can be effectively prevented while maintaining good release properties of the tire.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  1 to 2 show a tire vulcanizer according to an embodiment of the present invention, and FIG. 3 shows a lower bead ring thereof. As shown in FIG. 1, the tire vulcanizer of the present embodiment includes a pair of a lower mold 1 and an upper mold 2 that mold a portion from a tread portion to a sidewall portion of the tire T. The lower mold 1 and the upper mold 2 are configured such that the tread rings 3 and 4 are bolted at positions corresponding to the tread portion so that the tread pattern can be changed. A pair of lower bead ring 5 and upper bead ring 6 are disposed at a position corresponding to the bead portion of tire T. The lower bead ring 5 is fixed to a clamp ring, which will be described later, while the upper bead ring 6 is bolted to the upper mold 2.

  A piston rod 7 that is movable in the vertical direction is erected at the center of the mold. A lower clamp ring 9 is slidably attached to the piston rod 7 via a sliding ring 8, and an upper clamp ring 11 is fixed to the tip of the piston rod 7 by a cap 10. The lower bead ring 5 is bolted to the lower clamp ring 9, and the lower end portion of the bladder 12 is sandwiched between them. On the other hand, the mold ring 13 is bolted to the upper clamp ring 11, and the upper end portion of the bladder 12 is sandwiched between them.

  A movable plate 14 that can move up and down along the piston rod 7 is disposed below the lower bead ring 5, and the lower bead ring 5 is mounted on the movable plate 14. A register ring 15 is disposed below the movable plate 14.

  Here, as for the lower side bead ring 5, the part contact | abutted at least to the bead part of the tire T is divided | segmented on the circumference. That is, as shown in FIG. 1 and FIG. 3, the lower bead ring 5 has a ring-shaped inner peripheral portion that does not contact the bead portion of the tire T, but an outer periphery that contacts the bead portion of the tire T. The side part is divided on the circumference. As a result, the lower bead ring 5 includes an annular divided piece 51 and an arc-shaped divided piece 52. The annular divided piece 51 is disposed in the region directly above the movable plate 14, but the arc-shaped divided piece 52 is out of the region directly above the movable plate 14. Therefore, when the movable plate 14 moves in the tire axial direction, only the divided pieces 51 move in the tire axial direction together with the movable plate 14. The divided piece 52 may be fixed to the lower mold 1.

  Next, operation | movement of the tire vulcanizer mentioned above is demonstrated. First, as shown in FIG. 1, in a state where an unvulcanized tire T is inserted into a mold constituted by a lower mold 1 and an upper mold 2, heating is performed from the outside of the mold, and at the same time, the inside of the mold. The tire T is vulcanized by heating and pressing through the bladder 12.

  After vulcanization, as shown in FIG. 2, the upper mold 2 is removed, and the lower bead ring 5 is lifted together with the movable plate 14 to remove the vulcanized tire T from the lower mold 1. At this time, since a part (divided piece 51) of the lower bead ring 5 selectively moves in the tire axial direction, only a part on the circumference of the vulcanized tire T can be selectively lifted. Therefore, the force applied to the main groove forming bones 31 and 41 formed on the inner surfaces of the tread rings 3 and 4 is not evenly applied on the circumference at the time of mold release, so that the force applied to the tread portion of the tire T at the time of mold release is small. Therefore, the tread portion is difficult to be lost.

  As shown in FIG. 3, it is preferable that the portion that moves first in the lower bead ring 5 to lift the bead portion of the tire T is provided in a range in which the division angle θ around the ring axis is 90 ° to 270 °. By defining such a range, it is possible to effectively prevent block chipping while maintaining good release properties of the tire. If the division angle θ is less than 90 °, the releasability of the tire T becomes insufficient, and conversely if it exceeds 270 °, block breakage is likely to occur in the tread portion of the tire T. The most preferable range of the division angle θ is 90 ° to 180 °.

  4 to 6 show a tire vulcanizer according to another embodiment of the present invention. The tire vulcanizer of this embodiment is configured such that a part of the bead ring and the other part move in the tire axial direction with a phase difference. 4 to 6, the same components as those in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 4, the lower bead ring 5 includes an annular divided piece 51 and an arc-shaped divided piece 52 as in the above-described embodiment. On the side, a stepped portion 52a is provided. Then, when the movable plate 14 moves upward and the amount of movement reaches a predetermined size, the divided piece 52 is engaged with the movable plate 14 via the step portion 52a.

  Next, operation | movement of the tire vulcanizer mentioned above is demonstrated. First, as shown in FIG. 4, with an unvulcanized tire T inserted into a mold constituted by a lower mold 1 and an upper mold 2, heating is performed from the outside of the mold, and at the same time, the inside of the mold. The tire T is vulcanized by heating and pressing through the bladder 12.

  After vulcanization, the upper mold 2 is removed, and the lower bead ring 5 is lifted together with the movable plate 14 to remove the vulcanized tire T from the lower mold 1. At this time, as shown in FIG. 5, in a state where the movable plate 14 is slightly raised, a part (divided piece 51) of the lower bead ring 5 selectively moves in the tire axial direction. Only a part on the circumference of the tire T can be selectively lifted. Therefore, when the mold is released, no force is evenly applied to the main groove forming bones 31 and 41 formed on the inner surfaces of the tread rings 3 and 4, so that the force applied to the tread portion of the tire T is reduced and the tread is reduced. The part is difficult to lose. As shown in FIG. 6, when the movable plate 14 is further raised, the other part (divided piece 52) of the lower bead ring 5 has a phase difference (time difference) with respect to a part (divided piece 51) in the tire axial direction. Will move.

  In the above-described embodiment, the tire vulcanizer including the upper and lower split molds has been described. However, the present invention can be applied to a tire vulcanizer including the left and right split molds.

  In a tire vulcanizer equipped with a bead ring that abuts against a bead portion of a tire inserted into a split mold, the lower bead ring is divided on the circumference and a part of the lower bead ring is selectively The tire vulcanizers of Examples 1 to 3 configured to move in the tire axial direction were prepared. In Examples 1 to 3, the division angle θ of the portion that moved first in the lower bead ring to lift the bead portion of the tire was varied. For comparison, a tire vulcanizer (conventional example) in which a lower bead ring is integrally formed was prepared.

  Vulcanization of pneumatic tires (tire size 165 / 70R13) was repeatedly performed using the tire vulcanizers of Examples 1 to 3 and the conventional example. And while observing the releasability of a tire, the incidence of block chipping was examined for a vulcanized tire. The results are shown in Table 1.

この表１から判るように、実施例１〜３のタイヤ加硫機はいずれもタイヤの離型性が良好であると共に、従来例に比べてブロック欠けの発生率が低下していた。

As can be seen from Table 1, all of the tire vulcanizers of Examples 1 to 3 had good tire releasability, and the incidence of block chipping was lower than that of the conventional example.

It is sectional drawing which shows the tire vulcanizer (clamping state) which consists of embodiment of this invention. It is sectional drawing which shows the tire vulcanizer (at the time of mold release completion) which consists of embodiment of this invention. It is a top view which extracts and shows the lower bead ring of the tire vulcanizer which consists of an embodiment of the present invention. It is sectional drawing which shows the tire vulcanizer (clamping state) which consists of other embodiment of this invention. It is sectional drawing which shows the tire vulcanizer (middle mold release) which consists of other embodiment of this invention. It is sectional drawing which shows the tire vulcanizer (at the time of mold release completion) which consists of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lower mold 2 Upper mold 3, 4 Tread ring 5 Lower bead ring 6 Upper bead ring 7 Piston rod 8 Sliding ring 9 Lower clamp ring 10 Cap 11 Upper clamp ring 12 Bladder 13 Mold ring 14 Movable plate 15 Register ring 31 , 41 Main groove forming bone 51 52 Split piece 52a Stepped portion

Claims (3)

In a tire vulcanizer having a bead ring that abuts against a bead portion of a tire inserted into a split mold, an arc-shaped divided piece obtained by dividing a part of the bead ring in the circumferential direction; A tire vulcanizer constituted by an annular divided piece excluding the arc-shaped divided piece and configured to selectively move the annular divided piece in the tire axial direction.   The tire vulcanizer according to claim 1, wherein the arc-shaped divided piece and the annular divided piece are configured to move in the tire axial direction with a phase difference. The tire vulcanizer according to claim 1 or 2, wherein an annular divided piece that moves first in the bead ring and lifts the bead portion is provided in a range of 90 ° to 270 ° around the ring axis.

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