JPS6117356B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a three-phase cartridge heater, and particularly aims to provide a three-phase cartridge heater with stable quality.

In recent years, three-phase cartridge heaters have been attracting attention from the viewpoint of cost reduction in order to replace the conventional three sheathed heaters with one cartridge heater.

However, conventional three-phase cartridge heaters
As shown in the figure, three coiled heating wires 2 were inserted into a metal pipe 1 that was sealed on one side and filled with insulating powder 3. For this reason, the three heating wires 2 tend to come into contact with each other, and the eccentricity leads to a decrease in the withstand voltage.

The present invention eliminates the drawbacks of the conventional three-phase cartridge heater, and embodiments of the present invention will be described below with reference to the accompanying drawings.

In FIG. 2, 11 is a metal pipe sealed on one side. Reference numeral 12 denotes a columnar core formed by sintering insulating powder, such as magnesia powder, and heating wires 13 are wound around this core at a uniform pitch to form a completed core. The completed core is metal pipe 1
Three pieces are inserted vertically into 1. Reference numeral 14 denotes an electrode wire connected to one end of the heating wire 13 and led out to the opening of the metal pipe 11. The other end of the heating wire 13 is connected to the common electrode wire 15, and the three heating wires 1
3 is Y-connected. 16 is an insulating powder such as magnesia powder filled in the metal pipe 11, and 17 is a sealant for sealing the opening of the metal pipe 11.

In the above configuration, it is sufficient that the heating wires 13 do not come into contact with each other and get entangled, and that the distance between them and the metal pipe 11 is maintained, there is no need to worry about eccentricity, and dielectric strength is guaranteed.

The core 12 has a through hole formed in the center into which the common electrode wire 15 is inserted, and through holes into which the three electrode wires 14 are inserted are formed at equal intervals around this central through hole. When used, the shrinkage rate during sintering molding becomes uniform, and the strength and dimensional accuracy of the core 12 are improved.

Further, in the above embodiment, the case where three heating wires 13 are Y-connected is explained, but one end of the heating wire 13 is connected to one electrode wire 14, and the other end is connected to another electrode wire 14. △Connection may also be used. In this case, the common electrode line 15 becomes unnecessary.

As is clear from the above description, according to the three-phase cartridge heater of the present invention, since the heating wires for each phase are wound around each core, the heating wires do not get tangled with each other, and the quality is stabilized. , △
It can be easily connected and has great industrial value.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional three-phase cartridge heater, and FIG. 2 is a sectional view of a three-phase cartridge heater showing an embodiment of the present invention. 11...metal pipe, 12...core, 13...
Heating wire, 14... Electrode wire, 15... Common electrode wire,
16...Insulating powder.

Claims (1)

[Claims] 1. Wrap a heating wire around the outer periphery of a core made by sintering insulating powder into a columnar shape to form a completed core, insert three completed cores into a metal pipe sealed on one side,
A three-phase cartridge heater in which an electrode wire connected to one end of each heating wire is led out from an opening in a metal pipe, and the other end of each heating wire is connected to another electrode wire or the other end of another heating wire. .