JPH0321492B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing glass sealed bodies such as airtight windows and airtight terminals.

As an airtight window used for monitoring the liquid level in an airtight container, there is a structure shown in FIGS. 1 and 2, for example. In the figure, reference numeral 1 denotes an approximately donut-shaped metal outer ring, which has a large-diameter hole 2 in the center, a small-diameter hole 3 below the hole 2, and a stepped portion 4 between the holes 2 and 3. It also has an appropriate number of mounting holes 5 around the hole 2. A transparent glass 6 is hermetically sealed in the hole 2, and its upper surface 6a is a concave free surface, and its lower surface 6b is a flat jig contacting surface. This airtight window is plated for rust prevention, and the lower surface 1a of the metal outer ring 1 is fluid-tightly attached to the wall of the airtight container (not shown) with a packing made of asbestos or the like interposed therebetween. Therefore, the lower surface 1a of the metal outer ring 1 is required to have high flatness. However, conventionally, the lower surface 1 of the metal outer ring 1
There was a problem in that it was easy to cause unevenness or peeling of the plating on a, making it impossible to achieve a high level of liquid-tight sealing.

The inventor investigated the cause of this problem and found that it was related to the method of sealing the airtight window. That is, the above-mentioned airtight window is manufactured as shown in FIG. Reference numeral 7 denotes a graphite sealing jig, which has a protrusion 8 that fits into the hole 3 of the metal outer ring 1 in part. 1a is placed in contact with the upper surface 7a of the sealing jig 7 and the protrusion 8 is placed in the hole 3, and a transparent glass disc 6 is placed on the stepped portion 4 of the metal outer ring 1.
0 is placed thereon, the whole is heated to about 1000° C. in a neutral or weakly reducing atmosphere, and the transparent glass disk 60 is melted. Therefore, a so-called carburization phenomenon occurs in which free carbon from the sealing jig 7 intrudes into the lower surface 1a of the metal outer ring 1, which is the mounting surface of the airtight window to the wall of the airtight container, resulting in locally different surface conditions. ,
This causes unevenness and peeling of the surface.

Therefore, in order to prevent plating unevenness, plating peeling, etc. caused by the carburization phenomenon of the lower surface 1a of the metal outer ring 1, for example, the upper and lower surfaces of the metal outer ring 1 are reversed so that the lower surface 1a shown in FIG. It is not impossible to consider sealing with 1a facing upward. However, if this is done, the upper surface 6a of the transparent glass 6 becomes a rough jig contacting surface, resulting in a problem that the transparency of the transparent glass 6 deteriorates during use. In the airtight window shown in FIG. 2, the lower surface 6b of the transparent glass 6, which is the side surface of the airtight container, is the jig contact surface, so even if the lower surface 6b is rough, the liquid inside the airtight container When the transparent glass 6 comes into contact with the glass, it becomes highly transparent, as if the surface of the ground glass was wetted with water.However, as mentioned above, if the surface of the transparent glass 6 opposite to the airtight container side is roughened, This is because transparency does not increase. Furthermore, if the surface opposite to the airtight container side is rough, it is easy to attract dust and get dirty, which leads to the problem of further deterioration of transparency. Furthermore, in airtight terminals in which the lead wire is hermetically insulated and sealed inside the metal outer ring through glass, if dust adheres to the glass surface, the withstand voltage or insulation resistance between the metal outer ring and the lead wire may change. There was a problem in that it deteriorated.

Therefore, the main object of the present invention is to provide a method for manufacturing a glass sealed body such as an airtight window or an airtight terminal, in which carburization is unlikely to occur on the surface of the metal outer ring on which the metal ring is attached to the airtight container. It is.

In summary, this invention forms a downward step on the inner surface of a hole in a metal outer ring, a protrusion fits into the metal outer ring, and the upper shoulder of the protrusion covers the entire lower surface of the metal outer ring. It is characterized in that it is supported on a sealing jig in a state floating above the sealing jig and glass-sealed.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows a cross-sectional view for explaining the case of manufacturing an airtight window according to the present invention.
is a metal outer ring, which has a hole 12 in the center and an annular protrusion 13 halfway up the height of the hole 12;
The upper and lower surfaces of 3 are stepped portions 14. 15 is hole 1
This is a mounting hole provided around 2. Reference numeral 17 denotes a sealing jig made of graphite, and a part thereof is provided with a cylindrical protrusion 18 that fits into the hole 12 of the metal outer ring 11, and a stepped portion 19 is provided at the shoulder of the upper end of the protrusion 18.
is provided, and a part of the protrusion 18 is connected to the metal outer ring 11.
It is designed to fit into a cylindrical part formed by a protrusion 13 of the cylindrical part. Upper surface 17a of the sealing jig 17
The height dimension H1 from the step part 19 to the metal outer ring 1 is
1 to the lower surface of the protrusion 13 (H1>h1). Therefore, when the projection 13 of the metal outer ring 11 is placed on the stepped portion 19 of the sealing jig 17, the lower surface 11a of the metal outer ring 11 is separated from the upper surface of the sealing jig 17 as shown in the figure. Only H1−h1 is floating. In the above state, the step 1 on the upper surface of the protrusion 13 is further
A transparent glass disk 160 is placed on top of the transparent glass disk 160, and the whole is heated to about 1000° C. in a neutral or weakly reducing atmosphere to melt the transparent glass disk 160, and then cooled to solidify the glass. When removed from the sealing jig, an airtight window as shown in FIG. 5 is obtained.

In the airtight window manufactured as described above, the lower surface 11a of the metal outer ring 11, which is the mounting surface to the wall of the airtight container, is sealed to the glass with the lower surface 11a floating above the upper surface 17a of the sealing jig 17. Lower surface 11 of outer ring 11
There is no carburization phenomenon caused by free carbon of the sealing jig 17 on a, and therefore even when plating is performed, there is no occurrence of plating unevenness or plating peeling caused by carburization, and a flat surface is obtained, and asbestos etc. Airtightness is easily ensured when the container is fixed to an airtight container through packing. Note that since the sealing jig 17 is in contact with the lower surface of the protrusion 13 of the metal outer ring 11 and the inner surface of the hole 12 below the lower surface of the protrusion 13, carburization may occur. This part has nothing to do with airtightness, so there is no problem. Further, the upper surface 16a of the transparent glass 16 is a free surface, and the lower surface 16
Since b is the jig contact surface, clear glass 1
Transparency can also be ensured because the liquid in the airtight container gets wet on the contact surface of the jig 6.

In FIG. 4, a step 19 is provided at the upper end shoulder of the protrusion 18 of the sealing jig 17, and as shown in FIG. The protruding portion 18 is made to be slightly higher than the lower surface of the protruding portion 13 by eliminating the step portion 19.
The lower surface 16b of the transparent glass 16 may be aligned with the lower surface of the projection 13 of the metal outer ring 11 by supporting the stepped portion of the lower surface of the projection 13 of the metal outer ring 11 with the upper surface 18a.

FIGS. 6 and 7 show cross-sectional views when manufacturing a hermetic terminal according to the present invention. In the figure, 2
Reference numeral 1 denotes a metal outer ring, the inner lower end of which is formed into a large diameter portion 22, and is provided with a step portion 23 facing downward. 26 is a sealing jig, which has a cylindrical protrusion 2 in part.
7, and a lead wire insertion hole 28 is provided at the center of the protrusion 27. Above the protrusion 27 of the sealing jig 26 is the step 2 of the metal outer ring 21.
3 is supported. A glass tablet 240 is made by kneading fine glass powder with an organic binder, press-molding it into a cylindrical shape, and then calcining it to burn out the organic binder. The lead wire 25 passes through the center hole of the tablet 240 and is inserted into the lead wire insertion hole 28. The height H2 of the protruding portion 27 is set larger than the height h2 of the large diameter portion 22 of the metal outer ring 21, that is, the height h2 from the lower surface 21a to the stepped portion 23, and the lower surface 21a is sealed. Wearing jig 2
It is supported in a state where it is lifted from the top surface of 6 by a dimension of H2-h2. In this state, when the whole is heated to about 1000°C in a neutral or weakly reducing atmosphere, the glass 24 in which the glass tablet 240 is melted is fused to the metal outer ring 21 and the lead wire 25, as shown in FIG. An airtight terminal like this can be obtained. In this airtight terminal as well, carburization does not occur on the lower surface 21 of the metal outer ring 21, so it is possible to prevent plating unevenness and plating peeling caused by carburization, and the lower surface 21a can be made flat, so packing is avoided. It can be fixed airtightly to an airtight container. In the above embodiment, the metal outer ring has a single hole and one load wire is hermetically sealed. The same method can be applied to an airtight terminal having a structure in which one or more lead wires are sealed together.

As described above, the present invention provides a method for manufacturing a glass sealed body such as an airtight window or an airtight terminal in which at least glass is hermetically sealed in a metal outer ring, the entire lower surface of the metal outer ring is sealed. Since the glass seal is carried out by supporting the sealing jig in a floating state from the bonding jig, carburization phenomenon does not occur on the lower surface of the metal outer ring, and there is no possibility of matting unevenness or plating peeling caused by carburization. Since the bottom surface can be made flat, it is possible to easily and reliably ensure airtightness when attaching it to an airtight container via packing, and it also has the effect of providing a glass sealed body with a beautiful appearance. play.

[Brief explanation of the drawing]

Figure 1 is a plan view of a conventional airtight window, and Figure 2 is a top view of a conventional airtight window.
3 is a sectional view showing the assembled state before sealing to explain the conventional manufacturing method of an airtight window, and FIGS. 4 and 5 show an airtight window according to the present invention. A sectional view showing an assembled state before sealing and a sectional view of an airtight window, and FIGS. 6 and 7 show an assembled state before sealing when manufacturing an airtight terminal according to the present invention. FIG. 11, 21...metal outer ring, 11a, 21a...
Lower surface of metal outer ring, 16, 24...Glass, 17,
26...Sealing jig, 17a, 26a...Top surface of sealing jig, 18, 27...Protrusion portion.

Claims (1)

[Scope of Claims] 1. When manufacturing a glass sealed body in which at least glass is hermetically sealed within a metal outer ring, a downward step is formed on the inner surface of the hole in the metal outer ring, and A protrusion is fitted into this metal outer ring, and the upper shoulder of the protrusion is used to support the metal outer ring on a sealing jig with its entire lower surface floating above the sealing jig and seal the metal outer ring with glass. A method for producing a glass sealed body characterized by: 2. The method for manufacturing a glass sealed body according to claim 1, wherein the metal outer ring is sealed with glass in an unplated state, and plating is applied after glass sealing. 3. The method for manufacturing a glass sealed body according to claim 1, wherein the glass sealed body is an airtight window.