JPS6056390A - Method of producing long heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for manufacturing a long heater used as an industrial heating source such as an electric furnace heater. 3. Structure of conventional example and problems thereof The sheathed heater type, which has traditionally been used as a heater for electric furnaces, has recently become popular due to its ease of temperature control,11 and thermal efficiency11.This sheathed heater is shown in Figure 1. Connect the electrical outlet terminal 1 to
Roll into a le shape] ζ, ■, Jt! +&! Connect to both ends of 2,
Connect the electrical outlet terminal 1 at both ends to the center of the metal pipe 3, place the hot wire 2 in the shape of a loop at position 16, put the magnesia powder 4 into the metal pipe 3, and By applying vibration to the metal pipe 3, it is filled with magnesia powder and then rolled to reduce its diameter.

If bending is required, annealing is performed after O-dimensional rolling to further improve electrical insulation.
・Both ends of the heater are restrained by low melting point guns 5 and I and heat resistant resin 6.

However, the sheathed heaters used in electric furnaces are several meters long.
In the conventional manufacturing method of the heater, the electric outlet terminal 1 and the heating wire 2 become eccentric due to the vibration during filling the magnesia powder 4, and the dielectric strength between the metal pipe 3 and the electric outlet terminal 1 decreases. or electrical insulation deteriorates,
There was a drawback that the electrical characteristics as a sheathed heater were significantly impaired.

month of invention The present invention solves these conventional drawbacks and improves electrical properties.

In particular, a method for manufacturing a long heater with excellent dielectric strength is provided.

Structure of the Invention In order to achieve the above-mentioned object, the present invention provides a connection portion between the electrical extraction terminal and the coiled heating wire, and a portion of the coiled heating wire that is at least one force point. A disk-shaped ceramic core having an outer diameter slightly smaller than the inner diameter of the metal pipe, which has a hole in the center through which the hot wire passes through, and a plurality of holes around the hole through which the magnesia powder passes, is passed through the metal pipe. Fix it/Then, place the electric outlet terminal to which the disc-shaped ceramic core is fixed on the bottom side, and position it in the metal pipe at 9+, fill it with magnesia powder from the top side of the metal pipe, and roll it. This reduces the diameter and prevents the eccentricity of the electrical outlet terminal and heating wire due to vibrations during filling with Magne 7A powder, making it possible to manufacture long heaters with excellent insulation rigidity. be. .

Description of examples Embodiments of the present invention will be described below with reference to FIG.

In addition, as in FIG. 1, the structural part profit i/(7 will be explained using the same reference numerals.) -1 The metal pipe 3 is an NCF30Q with a length of 1500 fI+r, an outer diameter of 12.7 mm, and a wall thickness of 0.63 mm. (Product name: Incoro I800), and as the heating wire 2, the wire diameter is 0.
, 5 mm Nichrome wire type 1 was used. This heating wire 2 is shaped into a coil with a winding diameter of 2 mm, and an outer diameter of 2 mm is attached to both ends.
The electrical outlet terminal 1 was connected.

- Power cylinder 2 As shown in Fig. 8, in the center of the disc: a hole 8-1 with an outer diameter of 2.5 cm, through which the coiled heating wire 2 and the electrical outlet terminal 1 can pass. The outer diameter of 1.8-1 is possible when the magnesia powder penetrates the peripheral part of 8-1.
Outer diameter 1 (,1 mF, , with 8-24 holes of 6 mm)
A disk-shaped ceramic core 8 made of a magnesia molded body with a wall thickness of 5B is prepared, and /ζ is prepared.

The disk-shaped ceramic core 8 is passed through holes 8-1 at four locations, including the connecting portion between the electricity extraction terminal 1 and the coiled heating wire 2, and the coiled heating wire 2, using a heat-resistant inorganic adhesive. Fixed sazek.

As shown in Fig. 2, this is an electrical outlet having a disk-shaped ceramic core 8. Place '1j1. It was positioned using the air extraction terminal fixing jig 9.

After that, magnesia powder 4 is filled from the upper side of the metal gib 3, followed by rolling diameter reduction, annealing, and sealing steps according to the conventional manufacturing method of sheathed heaters. We completed 10 long heaters with a diameter of 11 mm, and made them 'FJ (Oni 1r: Reiyu 11-2o).

At this time, for comparison, 10 long heaters were similarly completed according to the conventional manufacturing method without using the disk-shaped ceramic core 8, and sample numbers 1 to 10 were used. That's the best long heater, Makoto I]j
5g shi, ko,;) result 11ro is shown in Table 1 5, (
(Left space below) Table 1 (From Table 1), long heaters with sample numbers 1 to 10 manufactured according to conventional manufacturing methods (with insulation 1ii1
4. the power is between 500V and 11 ooV; llH
'7:';k', two lower levels.

On the other hand, the long heaters manufactured by the manufacturing method of the present invention have a dielectric strength of 2000 V to 2500 V, which is a very high insulation strength compared to the long heaters manufactured using the conventional manufacturing method. showed that. .

As described above, according to the method for manufacturing a long heater according to the present invention, the electric intake U door, the terminal 1, and the coil insulator S' are:.

Since a disc-shaped ceramic core is provided at the connection portion of the hot wire 2, eccentricity will not occur even if a long electrical outlet width 1 is used.

1) Since disc-shaped ceramic cores are placed at several locations on the heating wire, eccentricity will not occur as well.

This makes it possible to significantly increase dielectric strength compared to conventional manufacturing methods.

In this example, a magnesia molded body was used as the disc-shaped ceramic core, but there are no particular restrictions on this.

The diameter and number of holes through which the magnesia powder penetrates - 1
, 5 and 4, respectively, but it is fine if the size is sufficient to allow the Magnenor powder to pass through the top and bottom of the disk-shaped ceramic core, and the disk-shaped ceramic core to be used may be It is better to have a large number of cores, but the number of cores is not limited to 5%. 1. Effects of the Invention As is clear from the above explanation [l], the present invention is applicable to electric rf
A metal pipe with an outer diameter smaller than the inner diameter, which has an 8-hole in the center through which the y-projection part and the coiled heating wire force i ``t'1. A long-nosed ceramic core with a circular disc-shaped diameter.
(The manufacturing method of the heater is b, c; JL!: Su, absolutely #
! Powerful and talented, it is possible to manufacture long heaters! l:
It is a dog of practical value.

[Brief explanation of drawings]

11th C! ,, Manufactured using conventional manufacturing methods, 61㎎8, +
t/ξ Cross-sectional view of a long baboon, a61 in Fig. 2 Embodiment of the present invention ('C is a perspective view of a disc-shaped ceramic core used)] Possible Zν is magnesia powder filled J? ′
1. Schematic cross-sectional view, Figure C (cross-sectional view of a long heat beam manufactured in t. Gune/A F, ) end, 8
Disc-shaped ceramic core, 8-1 hole, 8-2... hole.

Claims (1)

[Claims] At the connection part between the electricity output terminal and the coiled heating wire, and at least one corner of the coiled heating wire, there is a hole centered at which the electricity extraction terminal and the coiled heating wire pass through. 1 letter of magnesia powder was placed around the hole, and a circular ceramic core with a diameter smaller than the inner diameter of a metal pipe having multiple holes was penetrated. After fixing, fix the disc-shaped ceramic core (7) and position it in the center of the metal pipe with the terminal facing downward, and fill the metal pipe with Magnenor powder from the top, A method for manufacturing a long heater, characterized by reducing the diameter by rolling.