JPH10180765A - Tire vulcanizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to heat a tire uniformly while controlling an increase in equipment cost by forming an annular heating passageway extending along the periphery of a tire in a mold and filling the interior of the passageway with a liquid-type heating medium which can be heated by electromagnetic induction heating. SOLUTION: This tire vulcanizing device consists of annular heating passageways 11 formed extending along the periphery of a tire in the top and the bottom force 1, 2, of a m old. the passageways 11 are internally filled with a liquid-type heating medium such as silicone oil which can be heated by electromagnetic induction heating. Therefore, the heating medium is heated together with the top and the bottom force 1, 2 of the mold, which are uniformly and rapidly heated by the spontaneous convection of the heated heating medium. Consequently, it is possible to uniformly and rapidly heat a tire and thus efficiently produce a pneumatic tire of outstanding quality. Besides, it is possible to control a significant increase in equipment cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vulcanizing apparatus for vulcanizing a green tire by electromagnetic induction heating.

[0002]

2. Description of the Related Art In recent years, there have been proposals to vulcanize tires by electromagnetic induction heating in order to shorten the vulcanization time and increase productivity. An electromagnetic induction coil is arranged in a mold and its peripheral portion, and the tire is vulcanized more quickly than before using the Joule heat generated by the eddy current generated therein.

However, vulcanization by electromagnetic induction heating as described above tends to make the eddy current distribution non-uniform, making it difficult to perform uniform heating. As a countermeasure, it is possible to perform uniform heating by arranging a large number of electromagnetic induction coils on the periphery of the mold and controlling them individually, but if such a large number of electromagnetic induction coils are installed , Equipment costs will increase significantly.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a tire vulcanizing apparatus using electromagnetic induction heating, which can uniformly heat a tire while suppressing an increase in equipment cost. Is to provide.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a tire vulcanizing apparatus which vulcanizes and molds a green tire set in a mold by electromagnetic induction heating. An annular heating passage extending along the circumferential direction is formed, and the passage is filled with a liquid heat medium (for example, silicon oil or the like) that can be heated by electromagnetic induction heating.

[0006] Since the heating passage filled with the liquid heating medium is formed annularly in the mold along the circumferential direction of the tire, the heating medium is formed together with the mold by electromagnetic induction during vulcanization. Even if the mold is heated and the mold is unevenly heated on the circumference, the mold can be uniformly and rapidly heated by the natural flow of the heated heat medium. As a result, the temperature distribution of the entire mold becomes uniform during vulcanization, so that the quality of the tire can be improved. In addition, the vulcanization efficiency can be increased because the tire can be quickly heated.

In addition, since it is only necessary to form a heating passage in the mold and fill it with a liquid heat medium that circulates naturally, the cost can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows an example of a tire vulcanizing apparatus according to the present invention, wherein 1 is an upper mold and 2 is a lower mold. Reference numeral 3 denotes a bag cylinder that stands upright on the center axis of the lower die 2. The bag cylinder 3 includes a lifting rod 4 that is vertically movable by a drive mechanism (not shown). A lower clamp ring 5 is attached to the upper part of the bag cylinder 3.

An upper clamp ring 6 is mounted on the upper end of the lifting rod 4 projecting above the bag cylinder 3. The upper clamp ring 6 and the lower clamp ring 5
The upper and lower ends of a cylindrical bladder 7 made of thin rubber are attached to the upper and lower ends, respectively. Above the bag cylinder 3, a steam supply path 8 for supplying heated steam into the bladder 7 and a gas supply path 9 for supplying an inert gas for inflating the bladder 7 are provided.

An electromagnetic induction coil 10 is attached to the outer peripheral surfaces 1a, 2a and the inner peripheral surfaces 1b, 2b of the upper and lower molds 1, 2 formed in an annular shape, respectively.
After the green tire T is set in a mold while the bladder 7 is inflated and the bladder 7 is inflated, the green tire T is vulcanized and molded by electromagnetic induction heating. After the vulcanization, the pressure inside the bladder 7 is reduced, and the upper die 1 and the lifting rod 4 are raised to open.

According to the present invention, in the tire vulcanizing apparatus as described above, a plurality of annular heating passages 11 extending along the tire circumferential direction are formed in the upper and lower molds 1 and 2. The heating passage 11 is filled with a liquid heat medium such as oil which can be heated by electromagnetic induction heating. In the tire vulcanizing apparatus using electromagnetic induction heating as described above, the heating medium 11 filled with the liquid heat medium is provided in the mold in an annular shape along the tire circumferential direction, so that the heat medium together with the mold is provided. The upper and lower molds 1 and 2 are heated uniformly and quickly by natural convection of the heated heat medium. Therefore, the tire can be heated uniformly and quickly, so that a pneumatic tire with excellent quality can be efficiently produced. Moreover, since it is only necessary to form the heating passage 11 and fill it with the heat medium, the equipment cost does not increase significantly.

In the present invention, the electromagnetic induction coil 10
It is preferable to attach to the upper and lower molds 1 and 2 at predetermined intervals along the circumferential direction of the tire. For example, as shown in FIGS. 1 and 2, a total of eight electromagnetic induction coils 10 can be preferably provided at four locations at 90 ° intervals. Further, although not shown, the electromagnetic induction coil may have a shape arranged in an annular shape in the equator direction of the mold.

These electromagnetic induction coils 10 are located on the outer peripheral surfaces 1a, 2a and the inner peripheral surfaces 1b, 2b of the mold, close to the crown portion T1 and the two bead portions T2 where the thickness of the set green tire T is large. Preferably, it is provided at a position. When it is provided for the crown portion T1, it is preferable to dispose it so as to face the shoulder side where the thickness is increased.

It is preferable to provide a total of four annular heating passages 11 as shown in FIG. It can be preferably provided on the shoulder side of the crown portion T1 where the thickness of the green tire T is large, and in the vicinity of both the bead portions T2. It is preferable that the heating passage 11 disposed on the crown portion T1 side has a longitudinal sectional shape larger than that provided on the bead portion T2 side.

In the above embodiment, the electromagnetic induction coil 10 is mounted on the outer peripheral surfaces 1a, 2a and the inner peripheral surfaces 1b, 2b of the mold. Instead, as shown in FIG.
a, 2a and the inner peripheral surfaces 1b, 2b. In this case, it is preferable to bury at least a part of the electromagnetic induction coil so as to be exposed from the mold. This makes it possible to efficiently cool the electromagnetic induction coil 10 which becomes high in temperature.

FIG. 4 shows another embodiment of the present invention, in which a multi-part sectional type mold is used in place of the above-mentioned two-piece mold. 21 is an annular upper mold for molding one sidewall of the tire, 22 is an annular lower mold for molding the other sidewall, and 23 is a sector for molding the tread. The pair of upper and lower annular upper dies 21 and lower dies 22 are disposed vertically with their side wall forming surfaces facing each other, and on the outer peripheral side thereof,
It has a configuration in which a plurality of sectors 23 divided along the circumferential direction are arranged with the tread portion forming surface on the inner peripheral side.

Reference numeral 24 denotes a bolster plate for supporting the upper mold 21. Inside the bolster plate, a heat insulating plate 25 is provided.
Is buried. Reference numeral 26 denotes a spacer disposed below the lower mold 22. Reference numeral 27 denotes a segment disposed on the outer peripheral side of the sector 23 and holding the sector 23. The outer peripheral side of the sector 23 is connected to the container ring via an inclined surface. 2
8 is engaged.

The inner peripheral surfaces 21b, 22 of the upper die 21 and the lower die 22
In the vicinity of the bead portion T2 of b and the outer peripheral surface 28a facing the crown portion T1 of the container ring 28, the electromagnetic induction coil 10 partially exposed is embedded. The bolster plate 24 is raised to open the upper mold 21 upward, and the container ring 28 is raised. Through the engagement between the container ring 28 and the segment 27, the sector 23 is slid to the left side in the drawing. It will be open. on the other hand,
At the time of vulcanization, the operation reverse to the above is performed, and while moving the container ring 28 downward in FIG. 4, each segment 27 is pressed and moved rightward in the figure, and the sector 23 is moved downward with the upper die 21. The mold is clamped to the mold 22.

In such a sectional type mold, annular heating passages 11 extending along the tire circumferential direction are provided in the upper mold 21 and the lower mold 22, respectively, near both bead portions T2. Is filled with a liquid heat medium. The annular heating passage 11 is also formed in the segment 27 interposed between the container ring 28 and the crown portion T1 of the green tire T, and is filled with a liquid heat medium. The annular heating passage 11 is a single passage whose longitudinal cross-sectional shape is formed to be vertically long along the crown portion T1.

As described above, even in a tire vulcanizing apparatus which performs vulcanization molding by electromagnetic induction heating using a sectional type mold, the annular heating passage 11 filled with the above-described circulating heat medium is provided. In addition, the temperature distribution of the entire mold during vulcanization can be made uniform, and the same effect as described above can be obtained. In this embodiment, the crown-side heating passage 11 formed in the segment 27 may be provided in a container ring 28 as shown in FIG.

[0021]

As described above, the present invention relates to a tire vulcanizing apparatus which vulcanizes and molds a green tire set in a mold by electromagnetic induction heating. The heating passage is formed, and the passage is filled with a liquid heat medium that can be heated by electromagnetic induction heating. The tire can be uniformly heated while suppressing the rise.

[Brief description of the drawings]

FIG. 1 is a sectional view of an essential part showing an example of a tire vulcanizing apparatus of the present invention.

FIG. 2 is a plan view showing an example of a mold in which electromagnetic induction coils are attached at predetermined intervals in a circumferential direction.

FIG. 3 is an explanatory view of a main part showing a cross section of another example of the tire vulcanizing apparatus of the present invention.

FIG. 4 is an explanatory view of a main part showing a cross section of still another example of the tire vulcanizing apparatus of the present invention.

FIG. 5 is an explanatory view of a main part showing a cross section of still another example of the tire vulcanizing apparatus of the present invention.

[Explanation of symbols]

1,21 Upper die 1a Outer peripheral surface 1b, 21b Inner peripheral surface 2,22 Lower die 2a Outer peripheral surface 2b, 22b Inner peripheral surface 10 Electromagnetic induction coil 11 Heating passage 23 Sector 27 Segment 28 Container ring T Green tire T1 Crown T2 Bead section

Claims (4)

[Claims] 1. A tire vulcanizing apparatus configured to vulcanize and mold a green tire set in a mold by electromagnetic induction heating, wherein an annular heating passage extending in a tire circumferential direction is formed in the mold. A tire vulcanizer in which a liquid heat medium that can be heated by electromagnetic induction heating is filled in the passage. 2. The tire assembly according to claim 1, wherein electromagnetic induction coils are attached to the mold at predetermined intervals along a tire circumferential direction, and at least a part of the electromagnetic induction coil is exposed from the mold. Sulfurizing equipment. 3. The tire vulcanizing apparatus according to claim 2, wherein the electromagnetic induction coil is provided near a crown portion and both bead portions of the green tire. 4. The tire vulcanizing apparatus according to claim 1, wherein the heating passage is provided near a crown portion and both bead portions of the green tire.