JPH0658788B2 - Method for manufacturing stem for cathode ray tube - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a small cathode ray tube stem used as a viewfinder for a video camera or a television camera.

[Conventional technology]

Conventionally, the stem of a small-sized cathode ray tube of this type is manufactured by the method illustrated in FIG.

That is, as shown in FIG. 6 (a), first, the glass tube holding hole 100a of the lower metal 100 and the lead wire holding hole 1 around the glass tube holding hole 100a are formed.
The glass tube 101 for exhausting and the lead wire 102 are inserted into 00b, and the glass ring 103 is set in the lower mold 100 so as to surround each lead wire 102 from the outside. Then, the glass ring 103 is softened by heating it from the surroundings with a burner (not shown) or the like at a high temperature, and the upper die 104
And lower each lead wire 1 as shown in Fig. 6 (b).
02 is introduced into the lead wire introduction hole 104a of the upper mold, and the glass ring 103 is moved to the stem molding surface 104 of the upper mold.
It is manufactured by press-molding into a predetermined stem shape in b, integrating with the exhaust glass tube 101 and each lead wire 102, and then releasing.

[Problems to be Solved by the Invention] However, in the case of manufacturing a cathode ray tube stem by the above method, the glass ring 103 having a large height is press-molded into a flat stem shape, so that the glass accompanying the glass ring deformation at the time of press molding is formed. Of the lead wire 102, the diameters of the lead wire holding hole 100b and the lead wire introducing hole 104a are made slightly larger than the diameter of the lead wire 102 in order to facilitate insertion and introduction of the lead wire 102. Therefore, there is a problem in that the lead wire 102 is tilted or moved inside the hole due to the flow of glass during press molding, which makes it difficult to obtain accuracy. Particularly, the smaller the stem for a cathode ray tube to be manufactured and the shorter and shorter the lead wire, the larger the inclination and positional deviation of the lead wire and the more difficult it is to obtain accuracy. Manufacturing a tube stem was extremely difficult.

[Means for Solving the Problems]

In order to solve the above problems, the method for manufacturing a cathode ray tube stem of the present invention has a glass tube insertion hole in the central portion, and press-molds a stem matrix having a plurality of lead wire insertion holes around it with glass powder, The stem base, the glass tube for exhaust and the lead wire are set in the lower mold of a press molding machine, and the upper end of the lead wire is introduced into the lead wire introduction hole of the upper mold, while heating the stem base at high temperature. It is characterized by being pressed by upper and lower molds.

[Action]

According to the manufacturing method of the present invention, the lead wire is pre-inserted and positioned in the lead wire insertion hole of the stem matrix and the lead wire introduction hole of the upper die, and the stem matrix is formed by pressing after heating. Since the deformation and the flow of the glass are small, the lead wires are integrally sealed with almost no displacement or inclination. Further, the pressure during the press working improves the airtightness of the sealing between the lead wire and the glass of the stem base.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

According to the manufacturing method of the present invention, first, the stem base 1 as illustrated in FIG. 1 is press-molded with glass powder. The stem base 1 is formed by press-molding a material in which glass powder is mixed with an appropriate amount of a binder into a donut plate shape by using a press molding machine. And a plurality of lead wire insertion holes 3 are formed around it. The raw material glass powder needs to have a coefficient of linear expansion that is the same as or approximate to the coefficient of linear expansion of the lead wire to be inserted into the lead wire insertion hole 2. When using, for example, 426 alloy or Dumet wire as the lead wire, , Lead glass powder having a linear expansion coefficient of 97 × 10 ⁻⁷ , Kovar glass powder having a linear expansion coefficient of 45 × 10 ⁻⁷ , and the like are preferably used.

Next, as shown in FIG. 2, the stem matrix 1 is set in the lower mold 5 of the press molding machine in which the upper and lower molds 4 and 5 are opened, and the exhaust glass tube 6 is inserted into the glass tube of the stem matrix 1. While inserting from the hole 2 into the glass tube holding hole 7 of the lower mold 5,
The lead wires 8 are inserted into the lead wire holding holes 9 of the lower mold 5 through the respective lead wire insertion holes 3 of the stem base 1.

When the insertion of the exhaust glass tube 6 and the lead wire 8 is completed, the third
As shown in the figure, the upper mold 4 is lowered part way, and the upper end of each lead wire 8 is slightly introduced into the lead wire introducing hole 10 of the upper mold 4, and the stem mother body 1 is burner (not shown) or the like. To heat from ambient to high temperature. Thus, until the upper end of the lead wire 8 is slightly introduced into the lead introducing hole 10, the upper mold 4
Even if the stem base 1 is lowered, since the stem base 1 has a flat donut plate shape and is smaller in height than the conventional glass ring 103, the stem base 1 can be sufficiently heated from the surroundings. Regarding the heating conditions, considering the size of the stem base 1, the softening point of the glass, the melting point, etc., the heating temperature and heating time should be adjusted so that the surface layer of the stem base 1 is in a molten state and the inside is in a softened state. Is preferred.

Immediately after heating, the upper die 4 is pressed as shown in FIG. 4 to press the stem base 1 into a predetermined stem shape by the molding surface 11 of the upper die 4, and the exhaust glass tube 6 and the leads are formed. The line 8 is sealed and integrated. At this time, the glass flows along with the deformation of the stem base body 1, but since the stem base body 1 has a flat donut plate shape similar to the stem shape as described above, the stem base body 1 is deformed more than the conventional glass ring 103. The degree is much smaller and the glass flow is also slight. Moreover, since the lead wire 8 is inserted into the lead wire insertion hole 3 of the stem base body 1 and is in a pre-positioned state, the lead wire 8 is hardly displaced or tilted during this press working. Further, since the upper end of the lead wire 8 is slightly introduced into the lead wire introduction hole 10 of the upper mold 4 before the pressing, there is no fear that the lead wire 8 will be bent due to improper introduction during the pressing. Further, the pressure during the press working improves the airtightness of the sealing between the lead wire and the glass of the stem base.

As shown in FIG. 5, the cathode wire ring stem obtained by releasing the stem mother body 1 after pressing in this way has the lead wire 8 penetrating through the stem body 12 without inclination or displacement, and is sealed. It is attached, and is much more accurate than a stem for a cathode ray ring manufactured by a conventional manufacturing method. Further, since only the surface layer of the stem body 12 is transparent without bubbles and the inside is turbid due to bubbles, there is an advantage that it is unlikely to be broken when an external impact is applied.

〔The invention's effect〕

As is apparent from the above description, according to the manufacturing method of the present invention, it is possible to manufacture a highly accurate and highly airtight cathode ray tube stem with almost no positional deviation or inclination of the lead wire, and the shock resistance of the stem body. The effect of improving the
This is a particularly advantageous method in the case of manufacturing a microminiature cathode ray tube stem having an outer diameter of 10 mm or less.

[Brief description of drawings]

FIG. 1 is a perspective view of a stem base, and FIGS. 2 to 4 are stem bases, lead wires, and exhaust glass tubes set in a mold of a press molding machine by the manufacturing method of the present invention, and the stem base is pressed. 2 is a cross-sectional view for sequentially explaining the process, FIG. 2 shows a state before pressing with the upper and lower molds opened, FIG. 3 shows a state in which the upper mold is lowered halfway to heat the stem mother body, and FIG.
The figures respectively show the state where the stem base body is pressed.
FIG. 5 is a cross-sectional view of a cathode ray tube stem obtained by the manufacturing method of the present invention, and FIGS. 6 (a) and (b) are glass rings, lead wires, and an exhaust glass tube in a mold of a press molding machine manufactured by a conventional manufacturing method. Fig. 6 (a) shows the state before pressing with the upper and lower molds opened, and Fig. 6 (b) shows the glass ring being pressed by setting FIG. 7 is a partially enlarged view of FIG. 6 (a). 1 ... Stem base, 2 ... Glass tube insertion hole, 3 ... Lead wire insertion hole, 6 ... Exhaust glass tube, 8 ... Lead wire.

Claims (1)

[Claims] 1. A stem matrix having a glass tube insertion hole in the center and a plurality of lead wire insertion holes around the glass matrix is press-formed with glass powder to form the stem matrix, the exhaust glass tube and the lead wire. A cathode wire characterized by being set in the lower mold of a press molding machine, the upper end of the lead wire being introduced into the lead wire introducing hole of the upper mold, and being pressed by the upper and lower molds while heating the stem base at high temperature. Manufacturing method of pipe stem.