JPS59114042A - Tire vulcanizing device - Google Patents

Abstract

PURPOSE:To improve the thermal efficiency in case of heating making the heating temperature easy to control by a method wherein a metal die is heated by inducing alternate current with an electromagnetic coil arranged on the outside of a metal die for vulcanizing tire corresponding to the tire shape. CONSTITUTION:A flat spider coils 3 with inside diameter larger than tire inside diameter while outside diameter smaller than tire outside diameter are arranged on the wall surface of metal punch 1a and lower metal die 1b outside the side wall 2b of a tire 2. Then cylindrical coils 7 are arranged along the overall outside periphery of tread 2a of the tire 2 and mounting on the metal punch 1a and the lower metal die 1b. When both coils 3, 7 are supplied with alternate current, a metal die 1 is supplied with inducing current heating the metal die 1. In such a case, if the current is controlled corresponding to the required ideal vulcanizing temperature subject to specified coil turn and turn ratio of a transformer, each part of a tire may be vulcanized at an ideal temperaure.

Description

[Detailed Description of the Invention] The present invention relates to a tire muddying device, and more specifically, an electromagnetic coil is arranged outside a mold in which a tire is placed in accordance with the shape of the tire, and this electromagnetic coil is connected to an AC power source. ,
The present invention relates to a tire vulcanizing device that vulcanizes a tire by heating a mold using induction heating using an electromagnetic coil.

Conventionally, tire vulcanizing equipment has generally used a steam dome or a hot plate to heat a vulcanizing mold.

However, in steam dome type vulcanization equipment, the steam inside the dome must be discharged every time the vulcanization process is completed, which results in wasted energy consumption. There was a drawback that it was not possible to adjust the temperature to the ideal vulcanization temperature of the part.

In addition, hot plate type vulcanization equipment has the disadvantage that the heat generation temperature of the hot plate is extremely high, and the amount of heat radiated to the outside is large compared to the amount of heat transmitted from the mold to the tire, resulting in a high energy consumption rate. Generally, in the case of a hot plate, heating is performed only from both sides of the mold, which creates a unique temperature distribution in the tire inside the mold, which is not necessarily favorable in terms of tire performance.

In order to eliminate these drawbacks of the steam dome type and hot plate type, there is a jacket type mold that introduces steam directly into a chamber provided in the mold itself, but this requires the cost of the mold itself. There were also drawbacks such as the need for time and effort to connect the steam every time the product type was changed. In addition, the method of wrapping an electric heater directly around the mold has the disadvantage that the heater reaches a high temperature, so heat radiation is large and the energy consumption rate is high.If the heater is not in close contact with the mold, heat transfer is poor. If the mold was installed in a similar manner, it would require time and effort to replace the mold each time the product type changes.

The purpose of this invention is to eliminate the drawbacks of the conventional tire vulcanizing equipment, to reduce the energy consumption of the tire vulcanizing equipment, and to bring the mold temperature closer to the ideal vulcanization temperature of each part of the tire during tire vulcanization. The purpose of the present invention is to provide an excellent tire vulcanizing device capable of producing high-performance, high-quality tires.

In order to achieve the above object, in the present invention, a spiral coil is arranged on the outer wall of the sidewall portion of the tire of a tire vulcanization mold, and the outer wall of the tread portion of the tire is surrounded by a cylindrical coil, and the The feature is that the mold is heated.

The present invention will be described in detail below using the drawings.

FIG. 1 is a sectional view of an embodiment of the tire vulcanizing apparatus of the present invention, in which a mold 1, which is generally made of metal such as iron or aluminum, has an upper mold 1a and a lower mold 1b. Tire 2 between
After the tire 2 is installed inside the tire, it is heated from the outside to vulcanize the tire 2 inside.

In this invention, in order to heat the mold, the tire 2
A spiral coil 3 is installed on the wall surfaces of the upper mold 1a and the lower mold 1b outside the sidewall portion 2b. In this embodiment, the spiral coil 6 is formed into a flat shape with an inner diameter larger than the inner diameter of the tire 2 and an outer diameter smaller than the outer diameter of the tire 2, and is mainly responsible for heating the bead portion 2C of the tire 2. These spiral coils 3 and upper mold 1a,
The lower mold 1b is sandwiched between heat insulating materials 4. 5 is a stand, 6 is a lid, and 8 is a heat insulation cover.

Furthermore, in this embodiment, the tread portion 2a of the tire 2
The upper mold 1a and the lower mold 1
The cylindrical coil 7(3) is arranged so as to straddle the tread portion 2a and share the heating of the tread portion 2a.

This cylindrical coil 7 only needs to surround the entire circumference of the tread portion 2a of the tire 2, so it does not necessarily have to be one piece. Upper mold 1a
It may be configured with two cylindrical coils 7a and 7b for lower mold. The cylindrical coil 7 is divided into upper and lower halves like this.
By arranging the mold so that it moves to follow the mold, the temperature of the mold can be kept uniform even during the tire removal process, and the cycle time when vulcanizing the next tire is shortened. Also,
When the mold is opened, the cylindrical coil does not get in the way and the tire can be easily mounted on the mold and taken out from the mold.

FIG. 3 shows an embodiment of a control circuit for the spiral coil 3 and the cylindrical coil 7. Three-phase AC power supply T, S,
After R passes through the circuit breaker 11, it is divided into two different phases and connected to the primary sides of the spiral coil transformer 14 and the cylindrical coil transformer 15 via relay contacts 128 and 13a, respectively. The secondary side of the spiral coil transformer 14 is connected to the spiral coil 3 connected in series (4), and the cylindrical coil transformer 15
The secondary side of is connected to the cylindrical coil 7. 16 is a voltmeter, 1
7 is a capacitor, 18 is an ammeter, and 19 is a wattmeter.

Temperature sensors 22 and 23 are installed near the spiral coil 39 and the cylindrical coil 7, respectively, and their outputs are input to temperature controllers 20 and 21. Temperature controller 20, 2
1 is a relay coil 12b.

13b is energized and the relay contacts 12a, 1
The temperature of the coil 6.7 is adjusted by opening and closing 3a.

In the tire vulcanizing apparatus of the present invention configured as described above, when the spiral coil 3 and the cylindrical coil 7 are energized, the mold 1
An induced current flows and the mold 1 is heated. The heat generation temperature of the mold 1 depends on the magnitude of the induced current generated in the mold 1, so
The number of turns of the coil and the turns ratio of the transformer may be determined according to the ideal vulcanization temperature required for each part of the tire during tire vulcanization.

Figure 2 shows the temperature characteristics of each part of the tire 2 over time, obtained by determining the number of turns of the coil to meet the required temperature during vulcanization of each part of the tire 2 and controlling the current.The solid line shows the temperature of the tire bead part 2C. , the chain line indicates the temperature of the tire tread portion 2a, and the broken line indicates the temperature of the tire sidewall portion 2b. Thus, according to the device of this invention,
The tire can be vulcanized at a temperature that matches the ideal vulcanization temperature of each part of the tire.

As explained above, in the tire vulcanizing device of the present invention, an electromagnetic coil is arranged outside a tire vulcanizing mold according to the shape of the tire, and the effect of induced current generated by passing an alternating current to this coil is provided. By configuring the mold to be heated by heating the mold, there is an effect that the thermal efficiency during heating is improved and the energy consumption rate is kept low.

In addition, the heating temperature can be changed simply by changing the current flowing through the coil, making it easier to control the heating temperature and bringing the mold temperature closer to the ideal vulcanization temperature required for each part of the tire during vulcanization. This has the effect of making it possible to obtain high-performance, high-quality tires.

Furthermore, if an electromagnetic coil is placed independently in each divided mold, the mold can be opened and closed without being obstructed by the coil, making operation easier. If the current is turned on, the mold temperature will not drop, which has the advantage of shortening the vulcanization cycle.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of an embodiment of the tire vulcanizing device of the present invention, and Fig. 2 is a diagram showing temperature changes over time in various parts of the tire during vulcanization obtained by the tire vulcanizing device of Fig. 1. 3 is a circuit diagram showing one embodiment of the circuit for controlling the tire vulcanizing device of FIG. 1, and FIG. 4 is a sectional view of another embodiment of the tire vulcanizing device of the present invention. 1...Mold, 1a...Upper die, 1b...Lower die,
2... Tire, 2a... Tread part, 2b... Sidewall part, 2C... Bead part, 3... Spiral coil, 4... Heat insulating material, 7... Cylindrical coil, 11・・・
・Breaker, 12, 13...Relay, 14, 15・
...Transformer, 20.21...Temperature controller, 22.23
...Temperature sensor. throat p

Claims (1)

[Claims] A spiral coil is placed on the outer wall of the sidewall of the tire in a tire curing mold, and the outer wall of the tread of the tire is surrounded by a cylindrical coil, and these coils are connected to an AC power source via a current regulator. A tire vulcanizing device characterized by being connected.