JP2003011127A - Tire vulcanizing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tire vulcanizing machine which stabilizes the shape of a tire and prevents the generation of a temperature difference corresponding to the place of the tire during vulcanization to stabilize the quality of the tire. SOLUTION: In the tire vulcanizing machine having a freely expandable/ shrinkable bladder 5 pressing an unvulcanized tire T inserted into molds 1 and 2 from the inside to the outside, the bladder 5 has a multi-layer structure comprising a wire-woven layer 11 woven in an optional profile by using a wire, an outer bladder layer 12 of an elastic material and an inner bladder layer 13 holding the layer 11 between them, and an electricity passing means composed of a power source 14 for passing an electric current through the layer 11 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tire vulcanizer equipped with a bladder, and more specifically, it stabilizes the shape of a tire with a bladder capable of forming a profile, and has a temperature difference depending on the tire site during vulcanization. The present invention relates to a tire vulcanizer that prevents the occurrence of cracks and stabilizes the quality of tires.

[0002]

2. Description of the Related Art In a conventional vulcanization method using a tire vulcanizer, an unvulcanized tire is set in a mold, and then a single-layer bladder made of a material having low air permeability is steamed inside. Vulcanization is performed by introducing a heat medium such as or hot gas to inflate the tire and pressing the tire against the inner surface of the mold, and heating the tire from inside and outside. After vulcanization,
After opening the mold and shrinking the bladder, the vulcanized tire is taken out.

However, in addition to the problem that the shape of the bladder is not stable in the conventional tire vulcanizer, the tire is heated from the inside by the heat exchange between the heat medium introduced into the bladder and the tire as described above. In that case, there is a problem in that the heat medium is separated into a low temperature medium and a high temperature medium, and a temperature difference occurs during vulcanization depending on the tire site. That is, as shown in FIG. 4, the low temperature medium g ₁ is the bladder 5 ′.
Since the hot medium g ₂ tends to stay above the bladder 5 ′, there is a temperature difference depending on the part of the tire T during vulcanization. When such a temperature difference occurs, not only the energy efficiency during vulcanization is lowered, but also the tire quality is adversely affected.

Although a bladder equipped with an electric heater has been proposed, it is difficult to stabilize the quality of the tire because the shape of the bladder itself becomes unstable.

[0005]

SUMMARY OF THE INVENTION The object of the present invention is to stabilize the shape of a tire and prevent a temperature difference from occurring depending on the part of the tire during vulcanization, thereby stabilizing the quality of the tire. It is to provide a tire vulcanizer that makes it possible.

[0006]

A tire vulcanizer of the present invention for achieving the above object is provided with an expandable and contractible bladder for pressing an unvulcanized tire inserted in a mold from the inside to the outside. In the tire vulcanizing machine, the bladder, a wire woven layer woven into an arbitrary profile using a wire,
It is characterized in that it has a multi-layered structure of an outer bladder layer and an inner bladder layer made of an elastic material sandwiching the wire woven layer, and is provided with an energizing means for supplying an electric current to the wire woven layer.

According to the present invention, heat is exchanged between the bladder and the tire by applying an electric current to the wire woven layer constituting the bladder to heat the wire woven layer. It is possible to prevent a temperature difference. Moreover, since the wire woven layer is knitted into an arbitrary profile using a wire, the shape required for the bladder can be stably formed when the pressure medium is introduced into the inside of the bladder. Therefore, according to the tire vulcanizer equipped with the bladder having the multilayer structure capable of forming the profile, the quality of the tire can be stabilized.

In the present invention, it is preferable that the outer bladder layer is made of a material having mold releasability with respect to the tire, and the inner bladder layer is made of a material having lower gas permeability than the outer bladder layer. This makes it possible to simultaneously satisfy the mold releasability from the tire and the gas retaining property of the bladder.

[0009]

DETAILED DESCRIPTION OF THE INVENTION The configuration of the present invention will be described in detail below with reference to the accompanying drawings.

1 to 3 show a tire vulcanizer according to an embodiment of the present invention.

This tire vulcanizer, as shown in FIG.
A bladder 5 that includes a lower mold 1, an upper mold 2, a lower bead ring 3 and an upper bead ring 4 for vulcanizing an unvulcanized pneumatic tire T, and is inserted into the tire T It is provided with a lower bladder clamp 6 and an upper bladder clamp 7 for gripping. The lower bladder clamp 6 grips the lower inner peripheral end of the bladder 5 together with the lower bead ring 3. On the other hand, the upper bladder clamp 7 holds the upper inner peripheral end of the bladder 5 together with the clamp ring 8, and is vertically moved by the central mechanism 9 in the tire axial direction. That is, when the upper bladder clamp 7 moves downward, the bladder 5 expands in diameter, and when the upper bladder clamp 7 moves upward, the bladder 5 contracts in diameter. Further, this tire vulcanizer is equipped with a pressure medium introducing means (not shown) for introducing the pressure medium g into the bladder 5.

In the tire vulcanizer, as shown in FIG. 2, the bladder 5 has a wire woven layer 11 (heating element) woven into a desired profile using wires, and a wire woven layer 11 laminated outside the wire woven layer 11. Outer bladder layer 12
And an inner bladder layer 13 laminated inside the wire woven layer 11 have a three-layer structure. These three layers may be in intimate contact with each other or separated from each other.

The wire weave layer 11 is, as shown in FIG.
It is composed of a plurality of wires 11a extending in the tire width direction and a plurality of wires 11b extending in the tire circumferential direction. The profile of the wire woven layer 11 is set based on the lengths and the arrangement structure of the wires 11a and 11b. Each of the wires forming the wire woven layer 11 exhibits good dimensional stability with respect to the internal pressure applied to the bladder 5, and has electrical conductivity. A metal wire may be used as such a wire. The wire in the present invention is a generic term for wire materials such as cords and filaments.

As a constituent material of the outer bladder layer 12, it is preferable to use an elastic material having releasability with respect to the tire T. As such an elastic material, a rubber composition containing silicone rubber can be mentioned.

As a constituent material of the inner bladder layer 13, it is preferable to use an elastic material having a lower gas permeability than the outer bladder layer 12. As such an elastic material, a rubber composition mainly containing butyl rubber can be mentioned.

On the other hand, a bladder 5 is attached to the lower bead ring 3.
Power source 14 (energizing means) connected to the wire woven layer 11 of
Is provided. The wire woven layer 11 is heated by the current supplied from the power source 14. Of course, the temperature of the wire woven layer 11 can be controlled by the current value. The position of the power supply 14 is the wire woven layer 1
There is no particular limitation as long as 1 can be energized.

When tire vulcanization is carried out using the above tire vulcanizer, an unvulcanized pneumatic tire T is inserted into the molds 1 and 2 and the bladder 5 is expanded with the pressure medium g to form the tire T. After shaping, the mold is closed and the tire T is pressed against the inner surface of the mold. At this time, since the wire woven layer 11 is knitted into an arbitrary profile using a wire, the bladder 5 forms a required shape when the pressure medium g is introduced into the bladder 5, and the shape is It becomes extremely stable. Therefore, the shaping shape of the tire T before vulcanization can be properly adjusted.

After the mold is closed, the tire T is heated from the outside by heating the molds 1 and 2 while applying a predetermined internal pressure to the bladder 5, and the wire woven layer 11 is heated by the electric power supplied from the power source 14 to generate the tire T. The tire T is vulcanized by heating from inside. At this time, the wire woven layer 1
Since heat is exchanged between the bladder 5 and the tire T by causing 1 to generate heat, it is possible to prevent a temperature difference from occurring depending on the site of the tire T during vulcanization.

Therefore, according to the above tire vulcanizer, the shaping shape of the tire T before vulcanization becomes good,
Moreover, since there is almost no temperature difference depending on the part of the tire T during vulcanization, the quality of the tire can be stabilized.

In the above embodiment, the upper and lower mold halves are described, but the present invention includes an upper mold and a lower mold for molding the tire side portion and a plurality of sectors for molding the tire tread portion. It can also be applied to sectional type molds.

[0021]

As described above, according to the present invention, in a tire vulcanizer having an expandable and contractible bladder for pressing an unvulcanized tire inserted in a mold from the inside to the outside,
The bladder has a multi-layer structure including a wire woven layer knitted with a wire into an arbitrary profile and an outer bladder layer and an inner bladder layer made of an elastic material sandwiching the wire woven layer, and a current is applied to the wire woven layer. Since the energizing means is provided, the shape of the tire is stabilized, and
It is possible to prevent a temperature difference from occurring depending on the tire portion during vulcanization, and as a result, to stabilize the tire quality.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a tire vulcanizer according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view showing a bladder of the tire vulcanizer shown in FIG.

FIG. 3 is a perspective view showing a wire woven layer constituting the bladder of the tire vulcanizer shown in FIG.

FIG. 4 is a sectional view showing a conventional tire vulcanizer.

[Explanation of symbols]

1 Lower mold 2 Upper mold 3 Lower bead ring 4 Upper bead ring 5 bladder 6 Lower bladder clamp 7 Upper bladder clamp 8 Clamp ring 9 Central mechanism 11 wire woven layer 11a, 11b wire 12 Outer bladder layer 13 Inner bladder layer 14 power supply g Pressure medium T pneumatic tire

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4F202 AH20 CA21 CT01 CU12 CV12                       CV21                 4F203 AH20 DA11 DB01 DC01 DK07                       DL12 DL14

Claims (2)

[Claims] 1. A tire vulcanizer having an expandable and contractible bladder for pressing an unvulcanized tire inserted in a mold from the inside to the outside, wherein the bladder is braided into an arbitrary profile using a wire. A tire vulcanizer having a multi-layer structure of a wire woven layer and an outer bladder layer and an inner bladder layer made of an elastic material sandwiching the wire woven layer, and provided with an energizing means for supplying a current to the wire woven layer. 2. The tire according to claim 1, wherein the outer bladder layer is made of a material having releasability with respect to a tire, and the inner bladder layer is made of a material having a gas permeability lower than that of the outer bladder layer. Vulcanizer.