JPS5852312B2 - How to attach glass to sheathed heater terminals - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the method of attaching glass to a sheathed heater terminal.

The present inventor previously proposed a method of attaching an electric terminal to a sheathed heater terminal portion through a glass compound layer.

In this method, first, as shown in the first diagram, a terminal 4 is placed on the terminal portion 2 of a sheath tube 1 made of quartz or the like by penetrating an aggregate layer 3 made of magnesia powder, etc., and then placed on the aggregate layer 3. Granular, powdered or liquid glass solder 5 is supplied.

Next, as shown in the second diagram, the terminal part 2 is heated to melt the glass solder 5 and permeate through the upper surface of the aggregate layer 3 to form a glass compound layer 6, and is applied to the outer surface of the terminal 4 and the inner surface of the terminal part 2. Weld.

When cooled, the glass solder 5 solidifies, and as shown in the third figure, a glass compound layer 6 is formed on the terminal portion 2 of the sheath tube 1.
The terminal 4 is attached to the glass via.

Such a closed structure has the advantage that the glass compound layer 6 is resistant to thermal and mechanical shocks.

However, in the method of infiltrating the molten glass solder 5 from the surface of the aggregate layer 3, it takes time for the glass solder 5 to penetrate, and if the heating time is short, excess glass solder 5 remains in the upper part, causing cracks due to distortion. It has been found that there are drawbacks such as easy occurrence of.

In addition, heating for this glass attachment is normally performed from the outside of the sheathed tube 4, so the heating of the lower part of the electrical terminal 4 is delayed, and
For this reason, penetration and wetting of the glass solder 5 tend to be insufficient.
There were many drawbacks such as leakage and unreliable fixing of the terminal 4.

Furthermore, the sheath tube 1 is made of quartz with a small coefficient of thermal expansion (a=5X
107/℃) and crystallized glass (a=11~12X107
/'C), a glass layer 7 forming a filamentous structure between the glass compound layer 5 and the terminal portion 2 of the sheath tube 1
It is necessary to prevent damage due to thermal expansion difference by providing
In the penetration method described above, the density of the glass solder in the upper layer does not easily decrease, so it takes time to form a thread-like structure, and if the thread-like structure is formed insufficiently, the sheath tube 4 may break. Ta.

The present invention has been made in order to eliminate such drawbacks of the prior art, and aims to provide a method for attaching glass to a terminal in which the glass attachment is reliable and a thread-like structure can be easily formed.

The gist of the present invention is to first place a glass solder on the terminal surface, and then heat and melt the glass solder to permeate toward the periphery to form a glass compound layer and weld it to the inner surface of the sheathed tube terminal. This also made it possible to attach the glass reliably in a short period of time.

The details of the present invention will be explained below with reference to the embodiments shown in FIGS. 4 and 5.

First, as shown in FIG. 4, a terminal 4 with a glass solder 5 coated at least in the intended portion with glass is positioned along the center line of the terminal portion 2 of the sheathed tube 1, and the terminal 4 is surrounded by a glass solder 5. The aggregate layer 3 is densely packed.

Then, as shown in FIG. 5, heating is performed from the outer surface of the terminal portion 2.

Then, the heat of the terminal part 2 reaches the terminal 4 through the aggregate layer 3, melts the glass solder 5 on the surface, penetrates into the surrounding aggregate layer 3, and causes the terminal outside the aggregate layer 3 to melt. The glass solder 6 adhered to the terminal 4 is also melted by increasing the temperature of the terminal 4, and penetrates into the aggregate layer 3.

Then, when the glass solder 5 penetrates to the inner surface of the terminal part 2, heating is stopped and the terminal part 2 is cooled.

Then, as shown in FIG. 6, the terminal 4 is glass-bonded to the inner surface of the terminal portion 2 via the glass compound layer 6.

If the sheath tube 1 is made of a material having a small coefficient of thermal expansion, such as quartz, a glass layer 7 having a filamentous structure is formed between the inner surface of the terminal portion 2 and the glass compound layer 6.

According to this method, the molten glass solder 5 is moved from the vicinity of the terminal 4 in the center to the higher temperature sheath tube 1 terminal section 2.
Since it penetrates toward the inner surface, a glass compound layer is formed in a shorter time than before.Furthermore, since the lower side of the terminal 4 is coated with glass solder in advance, there is no possibility of leaks due to insufficient wetting or poor fixation of the terminal. There is no risk of

In addition, the amount of glass solder 5 can be easily controlled, and since no layer is formed on the aggregate layer 3, cracks in the glass compound layer 6 due to the formation of pools of glass solder 5, as in the conventional case, are avoided. Prevented.

Furthermore, by adjusting the heating time, it is possible to control the amount and strength of the glass solder 5 in the vicinity of the terminal, so if the sheath tube is made of a material with a low coefficient of thermal expansion such as quartz, the glass layer 7, which easily forms a filamentous structure, can be controlled. Can be formed.

Next, a specific example will be given and explained in detail.

Seed tube 1: Quartz tube with outer diameter of 6 wrl and inner diameter of 4.5 mm Aggregate layer 3: 40 to 200 mesh magnesha powder.

Terminal 4: Iron-nickel alloy round bar glass solder with a diameter of 2 wrL 5: The terminal 4 with glass is attached to the planned part and the part above this within a range of 15 mm Pbo B2O3S io 2 series glass (softened (temperature: 354°C) was coated to a thickness of 0.5m+++.

When such a member was glass-attached as described above, heating, which conventionally required 1.5 to 2 minutes, was completed in less than 1 minute, and the glass compound layer 6 with a thickness of about 10 wrL was heated. A glass layer 7 having a filamentous structure was formed.

This product could sufficiently withstand cooling and heating cycles from 0°C to 300°C.

The glass solder can be applied to the terminal by any conventionally known method, such as immersing the terminal in molten glass liquid and pulling it up, or applying glass powder to the terminal and baking it. The selection is made depending on the area to be penetrated and whether or not a filamentous structure is to be formed in the glass layer.

In general, if a filamentous glass layer is required, such as in a quartz sheathed tube, and sealing is not required, the amount of glass solder deposited is small.
If complete sealing is required, such as a metal sheathed pipe, use more.

The thickness of the glass solder to be applied is preferably 1 m or less; if it is thicker than this, a gap will be formed between the formed glass compound layer and the terminal, which is not preferable.

As described above, the method for attaching the sheathed heater terminal with glass according to the present invention is at least as follows: an electric terminal whose intended portion is coated with glass solder penetrates the aggregate layer filled in the terminal section of the sheathed tube. The glass solder is heated to melt the glass solder and permeate into the surrounding aggregate layer to form a glass compound layer, and is also welded to the inner surface of the terminal portion.
Glass solder penetrates into the aggregate layer more quickly and uniformly than before, and depending on the combination of materials between the sheath tube and the aggregate, the glass layer between the sheath tube and the glass compound layer can be easily and reliably formed into filaments. There are advantages to the organization.

[Brief explanation of the drawing]

Figures 1 to 3 are explanatory diagrams illustrating an example of the conventional method for attaching glass to the terminal part of a sheathed heater in the order of steps, and Figures 4 to 6 are illustrations of the method for attaching glass to the terminal part of a sheathed heater according to the present invention. FIG. 3 is an explanatory diagram illustrating one embodiment in the order of steps. 1...Sheath tube, 2...Terminal section, 3.
...Aggregate layer, 4...Terminal, 5...
・Glass wax, 6...Glass compound layer,
7...Glass layer forming a filamentous structure.

Claims (1)

[Claims] 1 At least with glass, an electric terminal whose intended part is coated with glass solder is placed through the aggregate layer filled in the terminal part of the sheath tube, and heated to melt the glass solder and remove the surrounding bone. A method for attaching glass to a terminal portion of a sheathed heater, characterized in that a glass compound layer is formed by infiltrating the glass compound layer into the material layer, and the glass compound layer is welded to the inner surface of the terminal portion.