JPH0527223B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method of manufacturing a tube, and in particular, heating the opening while filling an inert gas through an opening with one end closed and the other open. This invention relates to an improvement in a method for manufacturing a tube-shaped incandescent light bulb by sealing it.

Conventional structure and its problems Generally, in a tube such as a tube-shaped infrared light bulb, as shown in Fig. 1, a filament 2, a metal foil 3 such as molybdenum foil, etc. A mount 5 integrated with an external lead wire 4 is inserted, and an inert gas such as argon is filled into the mount 5 from an exhaust pipe 6 to perform sealing while preventing oxidation of the mount 5.

Recently, a method using a non-exhaust pipe valve has been adopted to simplify the process. That is,
To explain this with reference to FIG. 2, 7 is a non-exhaust tube quartz bulb for, for example, a tubular infrared light bulb, and the inside is connected via a tungsten filament 8, an internal lead wire 9, and a metal foil 10 such as molybdenum foil. An external lead wire 11 is provided,
An external lead wire 11 is led out from an opening 12 of the valve 7. Reference numeral 13 denotes a gas discharge nozzle, the inner diameter of which is larger than the outer diameter of the external lead wire 11. Further, the gas discharge nozzle 13 is disposed coaxially with the external lead wire 11, and is movable in the axial direction of the support body 14 of the external lead wire 11 shown in FIG.

Regarding the sealing operation, the external lead wire 11 led out from the opening 12 is passed through the gas discharge nozzle 13 and held by the lead wire support device 15 at the bottom of the nozzle. Next, move the gas discharge nozzle 13 upward so that the gas discharge port 16 of the gas discharge nozzle 13 is inserted 2 mm to 5 mm inward from the edge of the opening 12 of the valve 7, and while discharging the inert gas, The portion of the bulb 7 around the metal foil 10 is heated with a burner (not shown), and when the bulb 7 is softened, the gas discharge nozzle 13 is pulled out from the opening 12 of the bulb 7 and heated with a valve forming block (not shown). Crush and seal.

However, in this case, if the inner diameter of the opening 12 is reduced to about 4 mm, the gas discharge port 16 of the gas discharge nozzle 13 can only rise to the lower end of the metal foil 10, so that the inner surface of the heating part of the valve 7 is cooled by the discharged gas. As a result, there was a problem in that the sealing portion was not sufficiently sealed.

Purpose of the Invention The present invention has been made in view of the above-mentioned problems, and provides that the inner surface of the heating part of the valve is not cooled by the emitted gas, so that the sealing part can be sufficiently sealed. The present invention provides a method for manufacturing a tube that allows the following.

Composition of the Invention The method for manufacturing a bulb of the present invention is directed to an opening of a bulb made of glass, from which an external lead wire connected to a metal foil of a mount is led out through an opening that is closed at one end and open at the other end. , insert a pair of left-right symmetrical semicircular arc parts so that both sides of the metal foil are positioned in the gap between opposing end faces of these semicircular arc parts, and then An inert gas is discharged into the valve from the hole of the discharge nozzle, and the inert gas heats the vicinity of the opening while preventing air from flowing into the valve, and the semi-circular arc shape is released from the opening. The device is characterized by pulling out the opening and sealing the opening.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 4, 7 is a non-exhaust tube type bulb for a tube type infrared light bulb with an inner diameter of 4 mm, and is made of quartz glass. 10 is a metal foil made of molybdenum foil or the like; 1
1 is an external lead wire. 17 and 18 are a pair of semicircular arc-shaped parts provided symmetrically, and the valve 7
It extends in the same direction as the axial direction. The roots of these semicircular arc parts 17 and 18 are gas discharge nozzles 19.
It is connected to. A hole 20 for discharging inert gas is formed at the tip of the gas discharge nozzle 19.

FIG. 5 shows an enlarged sectional view taken along line A-A' in FIG.

Next, the sealing method will be described. The valve 7, through which the external lead wire 11 of the mount is led out through the opening 12, which is closed at one end and open at the other end, is evacuated with an exhaust machine (not shown), and after filling the gas inside the valve 7, the valve 7 is closed and the other end is open. Remove valve 7 from the exhaust machine,
The valve 7 is fixed to the holder of the sealing machine. After that, by moving the semicircular arc parts 17 and 18 upward,
External lead wire 11 led out from opening 12
, a part almost surrounded by semicircular arc parts 17 and 18,
and through the gas discharge nozzle 19, the holter 15
(Figure 4). At this time, metal foil 10
As shown in FIG.
It is located in the gaps 21 and 22 between the opposing end surfaces of Nos. 7 and 18. Then, an inert gas such as argon gas is discharged into the valve 7 from the hole 20 of the gas discharge nozzle 19, and the inert gas is used to prevent air from flowing into the valve 7 while preventing the valve from surrounding the metal foil 10. Heat the part 7 with a burner (not shown). When the heating progresses and the bulb 7 softens, the semicircular arc portions 17 and 18 are pulled out from the opening 12 of the bulb 7, and a pinch block (not shown) is activated to crush the heated portion and seal the opening 12. Stop.

According to the above configuration, even if the valve 7 has an extremely thin inner diameter of 4 mm, the semicircular arc portions 17, 1
8 can be inserted deep into the opening 20, and therefore the inner surface of the heating section of the valve 7 can be sufficiently prevented from being cooled by the inert gas. Therefore, the sealing portion of the valve 7 can be sufficiently sealed. It is preferable that the tips of the semicircular arc parts 17 and 18 be inserted 7 to 13 mm from the edge of the opening 12 of the valve 7. In addition, the total proportion of the gaps 21 and 22 between the opposing end surfaces of the pair of semicircular arcuate portions 17 and 18 is determined from the viewpoint of suppressing leakage of inert gas from the middle as much as possible. It is preferable that it is 30% or less of the circumference of the cylinder including 17 and 18. Furthermore, gaps 21 and 22
is narrower near the gas discharge nozzle 19,
It is better to widen it from here towards the above part.
This is preferable because there is less leakage of inert gas and the metal foil can be easily inserted.

Effects of the Invention As explained above, the present invention has a pair of symmetrical semicircular arc parts connected to the gas discharge nozzle, so even if the valve inner diameter is as small as about 4 mm, the semicircular arc shape The tip of the section can be inserted deep into the opening of the valve, so that the inert gas can be guided above the heating section of the bulb through the pair of semicircular arc sections. Therefore, cracks and leaks in the sealing portion due to cooling of the heating portion of the valve by the inert gas can be prevented, and the valve can be stably sealed.

[Brief explanation of the drawing]

FIGS. 1 and 2 are partially cutaway sectional views showing a conventional sealing device, FIG. 3 is an enlarged sectional view of the main part of FIG. FIG. 5 is an enlarged sectional view taken along line A-A' in FIG. 4. 7...Valve, 10...Metal foil, 11...External lead wire, 17, 18...Semicircular arc portion, 19...
Gas discharge nozzle, 20... hole, 21, 22... gap.

Claims (1)

[Claims] 1. An external lead wire connected to the metal foil of the mount is led out from the opening, which has one end closed and the other end open, into the opening of the bulb made of glass.
A pair of left-right symmetrical semicircular arc sections are inserted into the gap between opposing end surfaces of these semicircular arc sections so that both sides of the metal foil are positioned, and a gas discharge linking to the root of the semicircular arc sections is inserted. An inert gas is released into the valve from the hole of the nozzle, and the inert gas heats the vicinity of the opening while preventing air from flowing into the valve, and the semicircular arc-shaped part is heated from the opening. A method for manufacturing a tube, the method comprising: pulling out the tube, and sealing the opening.