JPH0857856A - Vacuum heating casting pot - Google Patents

Abstract

PURPOSE: To obtain a compact vacuum heating casting pot which is superior in thermal efficiency and easy in temperature controlling, by a method wherein a generating source of infrared rays or far infrared rays is arranged on the inside. CONSTITUTION: Generating sources each 16 are provided with a cylindrical infrared tube 32 or a far infrared tube 32 and an instrument main body 34 supplying electric power to the tube 32. The tubes 32 each are used by making a set with a reflector 36 which is arranged along the tube 32 and possesses an L-shaped sectional form and arranged on four corners of a pot main body 14 in a longitudinal direction. The tubes each 32 radiate infrared rays or far infrared rays by light emission and the rays heat a mold 20 as radiant heat directly or appropriately irrespective of a fact that the mold 20 is in a vacuum. Then since the reflector 36 reflects rays emitted uniformly in a circumferential direction of the tube 32 are made to reflect toward the mold 20. thermal efficiency is improved. Therefore, since the mold 20 is heated effectively by the infrared rays or far infrared rays from the tube 32 arranged within the pot main body 14, through which a temperature drop of the mold 20 is prevented reliably.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum heating casting pot used in a casting method for molding synthetic resin.

[0002]

2. Description of the Related Art Generally, electrical insulation parts of electrical equipment are
It is formed of a thermosetting resin material such as an epoxy resin material. One of the manufacturing methods of such resin products,
There is a casting method in which a molten synthetic resin material is poured into a mold. In this casting method, in order to prevent the molten synthetic resin material from partially solidifying due to a decrease in temperature while being poured into the mold, the mold to which the molten synthetic resin is poured is prior to the casting of this resin. Have been preheated. by the way,
When casting, in order to quickly and evenly spread the molten synthetic resin into the die, a vacuum pot for performing the casting in a vacuum atmosphere may be used. The mold placed in such a vacuum pot is also placed in the vacuum pot in a state where it is sufficiently preheated to prevent solidification during pouring of the molten synthetic resin material into the die.

However, if the degree of vacuum inside the vacuum chamber is increased to make the vacuum chamber vacuum after the mold is placed in the vacuum chamber, the temperature inside the vacuum chamber rapidly decreases as the atmospheric pressure decreases. However, the temperature of the mold itself also drops. In order to compensate for this temperature drop during vacuum operation and more reliably maintain the mold at a predetermined temperature, it has been attempted to heat the vacuum vessel from the outside. FIG. 2 is a vertical sectional view schematically showing a conventional vacuum heating casting pot. In the conventional vacuum heating casting pot 1, a pot for accommodating a mold 5 that receives a liquid resin material supplied via a hose 4 in order to prevent a temperature drop due to a pressure drop in the pot 3 due to the operation of the vacuum pump 2. Outside of 3,
An oil tank 6 surrounding the outer circumference of the kettle 3 is provided, and oil 7 in the oil tank 6 is heated by a heater 8. The oil 7 heated by the heater 8 warms the kettle 3 in contact therewith, and the kettle 3 warms the internal mold 5 by its radiant heat.

[0004]

However, in the conventional vacuum heating casting pot, the heat of the heating heater 8 which is a heating source is not directly applied to the mold 5, but is placed inside the pot 3 in vacuum. The heating of the mold 5 cannot be expected for heat conduction and convection, and depends exclusively on the indirect radiant heat of the pot 3 heated from the outside. As a result, there are drawbacks in thermal efficiency and temperature control, and there is a drawback in that the vacuum heating casting pot becomes larger. Therefore, an object of the present invention is to provide a compact vacuum heating casting kettle having excellent thermal efficiency, easy temperature control.

[0005]

According to the present invention, in order to solve the above-mentioned problems, a heating source is arranged inside a pot for holding a mold receiving a molten synthetic resin material in a vacuum atmosphere. In addition, as the heat source, a source of infrared rays or far infrared rays, which is one mode of heat transfer in vacuum and has excellent heat radiation properties, is used.

[0006]

In the vacuum heating casting pot according to the present invention, the source of infrared rays or far infrared rays placed in the pot together with the mold is
The radiant heat directly heats the mold without passing through the pot, so that the thermal efficiency is increased. Further, by controlling the electric power to the source of infrared rays or far infrared rays, it is possible to control the atmospheric temperature in the mold and the pot relatively easily. In addition, a vacuum heating casting pot can be made compact, since there is no need for a power supply device for the source of infrared rays or far infrared rays outside the pot, and no special device for heating to cover the pot. Becomes

[0007]

The present invention will be described in detail below with reference to the illustrated embodiments. FIG. 1 is a perspective view schematically showing a vacuum heating casting pot according to the present invention. Vacuum heating casting pot 10 according to the present invention
In the illustrated example, is a pair of doors 12 that can be hermetically closed.
And a box-shaped kettle body 14 having a box shape, and a generation source 16 for generating a plurality of infrared rays or far infrared rays arranged inside the kettle body 14. At the top of the hook body 14, the hook body 1
A vacuum hose 18 extending from a vacuum pump (not shown) for keeping the inside of the vacuum chamber 4 in a vacuum state is connected. An injection hole 24 is provided at the top of the kettle body 14 to which a supply hose 22 for injecting a molten synthetic resin material such as an epoxy resin material into a mold 20 arranged in the kettle body 14 is connected. Is provided.

FIG. 3 shows the pot body 14 of the vacuum heating casting pot 10.
It is a perspective view which shows an example of the metal mold | die 20 arrange | positioned inside. The mold 20 is, for example, a mold for an electrically insulating component such as an insulating cylinder or an insulating bushing used for a cable connecting portion, and a nozzle 26 and a gutter extending downward from an injection hole 24 to which a supply hose 22 is connected. The molten synthetic resin material is supplied from the injection port 30 provided at the top through 28. The mold 20 is sufficiently preheated prior to being placed in the pot body 14 to prevent solidification of the molten synthetic resin material during pouring into the mold 20. In this preheated state, the mold 20 is placed in the pot body 14.

Referring again to FIG. 1, when the mold 20 is placed at a predetermined position in the shuttle body 14, the vacuum door is closed after the sealing door 12 is closed and the vacuum pump is operated to bring the inside of the shuttle body 14 into a vacuum state. The main body 14 of the pot is operated by the suction action of the vacuum pump.
When the air inside is sucked through the vacuum hose 18, the temperature inside the pot main body 14 sharply drops as the atmospheric pressure inside the pot main body 14 drops, and the mold and the temperature also drop. In order to prevent this temperature drop, a source 16 for generating infrared rays or far infrared rays is arranged in the pot body 14.

Each source 16 is provided with a cylindrical infrared ray tube 32 or far infrared ray tube 32, and a device body 34 for supplying electric power thereto. Each tube 32 is a tube 3 in the example shown in FIG.
It is used in combination with a reflecting mirror 36 having an L-shaped cross-sectional shape, which is arranged along 2, and is arranged vertically at the four corners of the pot main body 14 and in which the mold 20 is arranged. Board 3
Below 8 is arranged in parallel in the horizontal direction. A material such as a mirror or a stainless plate can be appropriately selected as the reflecting mirror 36. In addition, a power lead wire (not shown) extending from each device body 32 is appropriately drawn out of the pot body 14 and connected to a power supply circuit.

Each tube 32 emits infrared rays or far infrared rays by light emission, and this light directly and appropriately heats the mold 20 as radiant heat regardless of the vacuum. Further, the reflecting mirror 36 improves the thermal efficiency by reflecting the light rays, which are uniformly radiated in the circumferential direction of the tube 32, toward the mold 20. Therefore, since the mold 20 is effectively heated by the infrared rays or far infrared rays from the tube 32 arranged in the pot main body 14, it is possible to reliably prevent the temperature of the mold 20 from lowering, for example, 120 degrees. It is possible to reliably maintain the mold 20 at the predetermined temperature.

As each tube 32, a curved tube other than a straight line can be used, and in order to effectively heat the mold 20 arranged in the pot main body 14, infrared rays or infrared rays are directed toward this mold. Various shapes and positional relationships can be adopted as the generation source 16 so as to radiate far infrared rays. Further, instead of combining the reflecting mirror 36 with the tube 32, a part or all of the inner surface of the pot main body 14 can be used as the reflecting mirror.

[0013]

As described above, according to the vacuum heating casting pot according to the present invention, the source of infrared rays or far infrared rays arranged in the pot together with the die is directly heated by the radiant heat of the die. By heating, the thermal efficiency can be increased. In addition, temperature control is facilitated, useless power consumption can be prevented, and production efficiency can be improved. Also,
Since the heating device that covers the pot is not required, the vacuum heating casting pot can be made compact, and since the heating source is covered by the pot, it is possible to suppress heat dissipation to the outside. As a result, the working environment can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view schematically showing a vacuum heating casting pot according to the present invention.

FIG. 2 is a vertical cross-sectional view schematically showing a conventional vacuum heating casting kettle.

FIG. 3 is a perspective view showing an example of a mold placed inside the vacuum heating casting kettle shown in FIG.

[Explanation of symbols]

 14 Kettle body 16 Infrared or far infrared source 20 Mold

Claims (3)

[Claims] 1. A vacuum heating casting kettle for holding a mold receiving a molten synthetic resin material in a vacuum atmosphere, in which a source of infrared rays or far infrared rays is arranged. 2. The vacuum heating casting kettle according to claim 1, wherein a reflecting mirror is provided in association with the generation source. 3. The vacuum heating casting pot according to claim 2, wherein the inner surface of the pot is a reflecting mirror.