JPS596238Y2 - Vacuum heating electric furnace - Google Patents

Description

[Detailed description of the invention] This invention is an electric heat treatment method that heats various metal parts, non-metal parts, chemical materials, porcelain teeth, and other objects to be heated under vacuum while covering them with a furnace body that uses electric heat as the heating source. This invention relates to a furnace in which the vacuum maintenance mechanism is stabilized and durable, and the thermal efficiency is further improved.

Electric furnaces, which heat treat objects under vacuum while covering the object with the furnace body, are widely used for heat treatment of various parts and materials, but conventional furnaces are usually placed on an extension wall of the furnace body. provided.

O-rings, etc. that maintain a vacuum state inside the furnace body are easily damaged by the heat of the furnace body, so there are some difficulties in heat treating with a bond that maintains a high degree of vacuum state around the object to be heated. It had a

One of the purposes of the present invention is to overcome these difficulties and develop an electric furnace that can easily maintain a high degree of vacuum.

In addition, in conventional electric furnaces of this type, the object to be heated is housed deep inside the furnace body and is heated by being covered by the furnace body. The amount of heat treated material is small, and therefore the amount of heat actually used for heat treatment of the material is relatively small compared to the total amount of heat consumed by the furnace body.

Another object of the present invention is to increase the proportion of the heat consumed by the furnace body that is actually used for heat treatment of the object to be heated, thereby improving the effective utilization rate of thermal energy.

The present invention will be explained based on drawings showing an embodiment thereof.As shown in Fig. 1, a desk 10 with a built-in power and control mechanism;
A running bracket 15 is installed on which a frame 11 is erected, and an electric heating furnace 14 consisting of a cylindrical furnace body 8 with an open bottom and an exterior fitting 13 that insulates the surroundings can be moved up and down as shown by the solid line arrow. .15 between the side columns 16, 16 of the frame 11, and directly below the furnace body 8 on the table 10, an air suction port 1 is opened 2 in the upper surface, and a cooling water While the base 3 provided with the passage cavity 9 is fixed, a large number of cup-shaped objects to be heated 17 are stored at the top,
A transparent heat-resistant heated object mounting table 4 made of quartz glass to be placed is provided, and below it are two identical disc-shaped heat ray shielding plates 5, also made of quartz glass and opaque and heat-resistant. Supports 6 are erected in the center of the base 3, and the pillars 6 are arranged horizontally at appropriate intervals vertically with their centers skewered. The upper end is sealed, and an O-ring 19 is provided on the bottom surface of the flange-shaped side edge 18 at the bottom of the opening to airtightly seal the inside by contacting the base 3. The transparent heat-resistant cylindrical body 7 also made of quartz glass is arranged so that its inner surface is very close to the periphery of each heat ray shielding plate 5, 5', and it is connected to the heated object mounting table 4 and the heat ray shielding plate 4. While covering the plates 5 and 5', the O-ring 19 is erected on the base 3 so as to press against it and seal the inside airtightly,
The electric heating furnace 14 is lowered as shown by the two-dot chain line in FIG. The structure is such that only the surrounding area of the table 4 can be covered and heated.

In an electric furnace having such a structure, the cylindrical body 7 is mounted on the base 3.
After removing the heated object 17 from the heated object mounting table 4 and storing it therein, the cylindrical body 7 is covered again, and a vacuum pump (not shown) is operated to remove the heated object 17 from the heated object mounting table 4 through the air suction pipe 1. The interior of the cylindrical body 7 is vacuumed, and the electric heating furnace 14 is lowered to a position where the furnace body 8 covers only the area around the object mounting table 4 of the cylindrical body 7, and then the electric heating is performed. When the furnace 14 is energized, the radiant heat rays from the furnace body 8 serving as a heat source pass through the transparent cylindrical body 7 and the side wall of the object mounting table 4 to raise the temperature of the object 17 to a predetermined temperature. , it is possible to perform the desired heat treatment.

At this time, the heat rays and the secondary radiation heat rays from the object to be heated 17 are blocked by the opaque heat ray shielding plates 5, 5' and do not reach the lower base 3. Since there are no heat rays radiating to the base 3 other than those passing through the small gaps between the heat ray shielding plates 5 and 5', the base 3 will not be overheated and the OIJ ring 19 etc. will be damaged. The degree of heat treatment is drastically reduced, allowing smooth heat treatment of the object to be heated 17.

In addition, since the furnace body 8 can heat only the area where the object to be heated 17 is present without heating the vicinity of the base 3 below, it has a smaller heat capacity than the conventional one. The furnace body can be used to perform sufficient heat treatment, and the effective utilization rate of thermal energy is significantly increased.

In the above-mentioned embodiment, the heat ray shielding plates 5, 5' and the heated object mounting table 4 are made of quartz glass, which releases gas from the inside and lowers the vacuum level, compared to when they are made of ceramic or the like. This is convenient because there are fewer troubles such as lowering the performance.

Furthermore, the base 3 has a built-in cooling water passage cavity 9, and by passing cooling water through the cavity 9 through the conduits 12, 12, the base 3 can be kept cool even more effectively.

Further, in the above-mentioned embodiment, the number of heat ray shielding plates 5, 5' is two, but it goes without saying that the number can be increased or decreased to three, four, or one as required.

Furthermore, the bottom of the heated object mounting table 4 may be made of opaque heat-resistant glass to serve also as a heat ray shielding plate.

Furthermore, in the above-mentioned embodiment, the furnace body 8 as shown in FIG.
The bottom cover 20 is attached so that it can move approximately 90 degrees in an arc-shaped trajectory between the front upper part and the rear lower part as shown by the broken line arrow, but this is because the electric furnace 14 is used. When lowering it, it is moved rearward and downward so as not to interfere with the lowering, and when the electric heating furnace 14 is temporarily stopped and raised, the bottom surface of the furnace body 8 is sealed to prevent heat dissipation within the furnace body. This is intended to be prevented as much as possible.

Note that the reference numeral 21 in the drawings indicates a thermocouple type temperature measuring device.

[Brief explanation of the drawing]

Fig. 1 is a partial longitudinal sectional front view of an embodiment of the present invention, and Fig. 2 is an assembled perspective view of each part of the base, heated object mounting table, heat ray shielding plate, transparent heat-resistant glass cylinder, and support column of the embodiment. . 1...Air suction pipe, 2...Opening, 3.
... Base, 4 ... Heated object mounting table, 5,
5'... Heat ray shielding plate, 6... Support column, 7
...Transparent heat-resistant glass cylinder, 8...Furnace body, 9...Cooling water passage cavity, 10...
Table, 11... Frame, 17... Heated object, 19... O-ring, 20... Bottom cover.

Claims (1)

[Claims for Utility Model Registration] On a base 3 with an air suction pipe 1 having an opening 2 on the upper surface, a heated object mounting table 4 is provided on the top, and an appropriate number of heat ray shielding plates 5,5'... . . . are installed horizontally in parallel, and the heated object mounting table 4 and heat ray shielding plate 5.5'.
. . . The transparent heat-resistant glass cylinder 7 is sealed so that its inner surface is very close to the periphery of each heat ray shielding plate 5.5' . The vacuum heating type is characterized by having a structure in which the furnace body 8 covers only the surrounding area of the object to be heated table 4 of the transparent heat-resistant glass cylinder 7 and heats it, while the entire structure is erected. Electric furnace. 2. The vacuum heating electric furnace according to claim 1, wherein the heat ray shielding plates 5,5' are made of opaque heat-resistant glass.