JPS647019Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a vacuum furnace, and particularly relates to a cable connected to a heater in a vacuum furnace and a connection structure between the heater and the cable.

Generally, a cable installed in a vacuum melting furnace, brazing furnace, vapor deposition furnace, etc. is installed on a table that moves up and down, and is connected to a heater in the furnace by passing through the table. This means that if the cable is provided in a part other than the table, the heater is provided on the table, so the cable must be slackened into the furnace by a length corresponding to the distance the table is moved. This slack reduces the effective usable area inside the furnace, scrapes the furnace wall when the table goes up and down, and it costs money to take measures to prevent high temperatures, so this structure is rarely used. The reality is that it has not been done. Hereinafter, a vacuum furnace in which a cable is provided on a table will be explained based on FIG. 1.

FIG. 1 is an internal structure diagram showing an example of a conventional vacuum furnace. In FIG. 1, a table 2 is provided on top of a water jacket 1 whose cavity is filled with circulating cooling water. A melting furnace 4 with a heater 3 disposed on the outer wall is installed.
The external power source 5 is connected to a cable 6, which passes through the water jacket 1 and the table 2 and is connected to the heater 3. Furthermore, the central portion of the water jacket 1 is provided with an operating rod 7 from a lifting/lowering operating mechanism (not shown) for the table 2. A furnace jacket 8 and a lid 9 attached to the upper part of the furnace jacket 8 are provided on the top of the melting furnace 4 to enclose the melting furnace 4 and create a vacuum state.
The hollow portions of the furnace jacket 8 and lid 9 are filled with circulating cooling water. Further, an exhaust pipe 10 for degassing is fixed to the furnace jacket 8a. Furthermore, a heat shielding reflector 11 is provided on the inner wall of the furnace jacket 8 and the lid 9.
is provided.

When brazing or heating a specimen in such a vacuum furnace, the table 2 is raised and the melting furnace 4 is hermetically sealed, and then the inside of the furnace is degassed from the exhaust pipe. Then, when a predetermined degree of vacuum is reached, the power to the heater 3 is turned on.

Here, the cable 6 that passes through the water jacket 1 and the table 2 and is connected to the heater 3 has a high frequency of raising and lowering the table 2, so that the outer sheath of the cable 2 may be damaged or become a hindrance to the work. It was. An even bigger problem is that since the cable 2 passes through the water jacket 1, cooling water can penetrate into the cable 2, deteriorating the insulation, and creating a short circuit, which is very dangerous. Furthermore, the packing structure for preventing cooling water leakage and vacuum leakage has become quite complex. These problems become more complicated and costly as the current capacity of the heater 3 increases.

In order to eliminate the above-mentioned problems, the present invention does not pull out the cable from the table, but rather pulls it out from the jacket part of the furnace body, and also provides opposite electric contacts in the vacuum furnace and connects one of the electric contacts to the cable. The other electrical contact is connected to the heater, and the two electrical contacts are electrically connected when the table is raised and the furnace is sealed. This eliminates damage to the cable sheath and also eliminates the obstruction from the work. Furthermore, since the water jacket 1 is not penetrated, cooling water does not penetrate into the cable, which eliminates insulation deterioration and short circuits.Furthermore, the packing structure for preventing cooling water leakage and vacuum leakage is different from conventional ones. It was simpler than the previous one.

The vacuum furnace according to the present invention will be explained below with reference to FIGS. 2 to 4.

Fig. 2 is an internal structural diagram showing an embodiment of the vacuum furnace according to the present invention, Figs. 3a and 3b show an embodiment of the upper electrical contact, Fig. FIG. 4 is a partially sectional front view showing an example of the lower electrical contact. In the figure, the same reference numerals as in FIG. 1 have the same functions, so their explanation will be omitted here. Omit.

In FIG. 2, the cable 6 is drawn out from the furnace jacket portion 8a which is not filled with cooling water, that is, from the exhaust pipe 10 side. Further, the vacuum furnace is provided with electrical contacts 12 and 13 facing each other, one electrical contact 12 is connected to the cable 6 via a lead wire 12a, and the other electrical contact 13 is heated via a lead wire 13a. It is connected to the thermal heater 3.

That is, the upper electrical contact 12 is attached to the reflector 11, and the lower electrical contact 13 is fixed to the upper part of the insulator 13c provided on the upper part of the support 13b installed vertically on the table 2.

Next, the detailed structure of the electrical contacts 12 and 13 will be explained in the third section.
This will be explained based on the diagram and FIG.

In FIGS. 3a and 3b, the holder 12b of the upper electrical contact 12 is attached to the reflector 11 with a screw 12c.
A lead wire 12a attached to the insulator tube 12d and inserted into the insulator tube 12d is connected to a contact point 12g via a terminal 12e and a tightening terminal 12f. In addition, a spring 12h with a contact 12g inserted into the holder 12b.
is included.

In FIG. 4, the lead wire 13a inserted into the insulator tube 13d is connected to the contact 1 of the lower electrical contact 13 via the connecting conductor 13e inserted into the support 13b.
Connected to 3f. Further, the contact 13F is fixed to the upper part of the insulator 13c with a nut 13g.

Thus, when energizing the heater 3 in the vacuum furnace configured as above,
When the table 2 is raised and the inside of the furnace is sealed, both electrical contacts 12 and 13 become electrically connected.

Here, the cable 6 is connected to the table 2 which ascends and descends.
Since the cable 6 is not pulled out from the cable 6, the outer sheath of the cable 6 is not damaged. In addition, since the cable 6 is pulled out from a place unrelated to the work area, it no longer becomes a hindrance to the work. Also,
Since the water jacket 1 is not penetrated, the cooling water does not penetrate into the cable 6, thereby eliminating deterioration of insulation and short circuit. Furthermore, the packing structure for preventing cooling water leakage and vacuum leakage is simpler than conventional ones.

As explained above, the vacuum furnace according to the present invention is
By installing opposing electrical contacts in the furnace, the cable can be pulled out from the table, which not only improves work efficiency but also eliminates the risk of electrical leakage, and is also economically inexpensive. can be provided.

[Brief explanation of the drawing]

Fig. 1 is an internal structural diagram showing an example of a conventional vacuum furnace, Fig. 2 is an internal structural diagram showing an embodiment of the vacuum furnace according to the present invention, and Fig. 3 a and b are an embodiment of the upper electrical contact. FIG. 4 is a partially sectional front view showing one embodiment of the lower electrical contact. 2...table, 3...heater, 4...
Melting furnace, 6...cable, 8...furnace jacket, 8a...furnace jacket portion not filled with cooling water, 9...lid, 12, 13...electrical contacts.

Claims (1)

[Scope of utility model registration request] a furnace jacket; a lid that caps the furnace jacket; a table that is disposed below the furnace jacket and forms a sealed structure when raised and abuts against the furnace jacket; In a vacuum furnace consisting of a heater provided on the outer wall of the melting furnace and a cable pulled out from the lower part of the table, the cable is pulled out from the jacket part of the furnace body and is placed oppositely in the vacuum furnace. Equipped with electrical contacts that
One of the electrical contacts is connected to the cable, and the other electrical contact is connected to the heating heater, so that when the table is raised and the inside of the furnace is sealed, both electrical contacts are in a conductive state. A vacuum furnace characterized by: