JPH0245985Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a sheathed heater equipped with a welded metal fitting joined by plasma welding.

Conventional structure and its problems Conventionally, plasma welding has been used to weld the terminals of this type of sheathed heater, but with this method, the sealing of the sheathed heater is caused by mechanical impact from above during welding. Loads were applied to the parts, which could easily cause the glass sealing material to crack, causing insulation deterioration. As shown in FIG. 1, a welding fitting 3 is spot-welded to a terminal 2 that constitutes a part of a sheathed heater 1, and the end of a lead wire 6 is fastened with a fitting 5, and then a round screw 4 is attached to the terminal 2. The conventional configuration was one in which the welding fitting 3 was screwed into the screw hole 7. Here, the method of spot welding the terminal 2 and the welding fitting 3 in FIG. 1 will be explained in detail in FIG. 2.
The tip of the terminal 2 is placed against the side surface 8 on the terminal side of the punched hole of the welding fitting 3, and spot welding is performed with the terminal 2 in contact with the projection 9.
The contact part is melted and joined. However, at this time, a mechanical shock is applied to the terminal 2, and the shock is also transmitted to the sealing part of the sheathed heater.
The glass sealing material could crack, which could easily cause insulation deterioration. In contrast to these welding methods, plasma welding, which can melt the contact area by blowing an arc without applying mechanical impact, is well known, but this conventional metal fittings require plasma welding. It is difficult and unstable to control the position, and in projection, the arc is difficult to fly, resulting in a lack of welding strength.

Purpose of the invention The present invention was made to solve the above-mentioned conventional problems, and its object is to provide a sheathed heater that can firmly and accurately weld a welding fitting to a terminal.

Structure of the Invention In order to achieve the above object, the sheathed heater of the present invention includes a welding fitting having a recess for receiving a longitudinal side surface of a terminal and a protrusion facing the terminal tip, and the terminal is received in the recess. By plasma welding the tip and the tip of the protrusion, the welding fitting can be accurately positioned and firmly attached to the terminal of the sheathed heater.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 3 and 4.

In FIG. 3, members that are the same as those in the prior art are given the same reference numerals and their explanations will be omitted. 10 is a welding metal fitting 11
12 is a punched hole provided to facilitate welding by plasma welding, and 13 is a recess provided along the central axis of the welding fitting 11. Then, the terminal 2 comes into contact with the above-mentioned protrusion 10 along the recess 13, the tip of the terminal 2 stops against the tip side surface 14 of the protrusion 10, and at the same time an arc is ejected to this contact portion, I'm trying to weld. 15
is a screw hole into which a screw is screwed to connect a lead wire, etc. for wiring. As shown in FIG. 4, the terminal 2 protruding from the sheathed heater 1 is plasma welded at a portion 16 on the side surface of the tip of the protrusion 10, and the contact portion is melted and joined.

In this way, in this embodiment, the side surface of the terminal 2 is formed into a recess 1.
3 and the tip of the terminal 2 is brought into contact with the tip side surface 14 of the protrusion 10, so the welding fitting 11 can be accurately and firmly welded to the terminal 2. In addition, since the welding fitting 11 is provided with a recess 13 and a protrusion 10 connected to the punched hole 12, the recess 11
3 is easy to form, and the welding fitting 11 as a whole is easy to form.

In the embodiment, the recess 13 is formed by bending the welding fitting 11, but the shape is not particularly limited to this, and any shape may be used as long as the position of the terminal 2 can be easily controlled.

In the above embodiment, the tip of the terminal 2 is brought into contact with the tip side surface 14 of the protrusion 10 and plasma welded between them. Even if the tip of the terminal 2 is brought into contact with the rising side surface of the terminal 10 and the two are plasma welded, the same effects as in the above embodiment can be obtained.

Effects of the Invention As is clear from the above examples, the sheathed heater of the present invention enables plasma welding that improves the performance and quality of the main body, improves welding workability and quality, and maintains a constant welding strength. It is something that can be done.

[Brief explanation of the drawing]

FIG. 1a is a plan view showing the connection state of a conventional sheathed heater, FIG. 1b is a side view of the same, FIG. 2 is a perspective view of the same welding fittings, and FIG. FIG. 4 is a perspective view of the sheathed heater. 2...Terminal, 10...Protrusion, 11...Welding fitting, 13...Recess.

Claims (1)

[Scope of utility model registration request] A sheathed heater comprising a welding fitting having a recess for receiving a longitudinal side surface of a terminal and a protrusion opposite to the terminal tip, the terminal being received in the recess and the tip of the terminal and the tip of the protrusion being plasma welded.