JPS6369124A - Manufacture of high pressure sodium lamp luminous tube - Google Patents

Abstract

PURPOSE:To enable inexpensive manufacturing of this tube with a good working efficiency and a long life, by using the first and second specific sealing processes and a sodium amalgam sealing process. CONSTITUTION:An end opening part 1a of a transmitting luminous tube bulb 1 made of ceramics is sealed with an enclosure 2A made of ceramics through glass solders 5A under a vacuum or an inert gas atmosphere so that the first sealing is completed. Concurrently in this first sealing process, a niobium tube, on one end of which an electrode 4A is held and the other end of which is sealed, is sealed in a through hole formed in the enclosure 2A through a glass solder mold 5. Then, under an inert gas atmosphere, sodium amalgam 6 is sealed-in and the air is exhausted, and thereafter the other end opening part 1b of the luminous tube bulb 1 is sealed with an enclosure 2B made of ceramics through the glass solder mold 5 so that the second sealing is completed. Concurrently in this second sealing process, a niobium line 8 for holding an electrode 4B is sealed in a through hole formed in the enclosure 2B through the glass solders 5A.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a method for manufacturing a high-pressure IJ lamp arc tube.

(Conventional technology) Traditionally, translucent ceramics such as alumina have been used.

High-pressure sodium lamps are known that use ceramics made of high-density polycrystals such as yttoria and magnesia or ceramics made of metal oxide single crystals such as ruby and sapphire as arc tube bulbs. Since the ceramic in this arc tube bulb is a high-melting point material, the open end cannot be heated and melted to seal it by crushing, as is the case with quartz glass arc tube bulbs. The electrodes are hermetically sealed using a closing body made of ceramics using glass solder as a sealing material, and the electrodes are held in this closing body. The interior of such an arc tube must be evacuated and filled with sodium amalgam and a starting rare gas, and the following various methods have been conventionally adopted for this exhaust sealing process.

That is, as an example of this, as shown in the diagram of FIG. 2, the openings (la) and (lb
) and a closure body (2A) made of alumina ceramic.
), (2B), electrode (4A), (4b),
Glass solder molded bodies (5), (5) as sealing materials, a niobium tube (3) inserted through one of the closing bodies (2 people) as an electrode support, and a niobium wire inserted through the other closing body (2B). (8), and heat and melt the glass solder molded bodies (5) and (5) in a vacuum or inert gas atmosphere. (1) Both end openings (la), (xb
) are sealed with closure bodies (2A) and (2B).

Next, sodium amalgam (6) is sealed from one end opening (3a) of the niobium tube (3), and one arc tube bulb (1) is inserted.
After evacuating the inside, a rare gas for starting is filled in, and one end opening (3a) of the niobium tube (3) is hermetically sealed as shown in Figure 0.

The luminous tube is completed. According to this method.

The sealing and exhaust processes are separate processes, which not only reduces work efficiency, but also allows air to enter the arc tube, albeit temporarily, after the sealing process. The disadvantage is that the emitter (not shown) deteriorates.

In addition, Fig. 3 shows another manufacturing method. First, as shown in the figure, one end opening (1a) of the arc tube pulp (1) is connected with a closing body (two people) via a glass solder (5A). The first sealing is performed, and at the same time the niobium wire (4A) is held therein.
8) is also sealed to the closure body (2 people) using glass solder (5 people). Next, the other end opening (1b) of the arc tube pulp (1)
) is filled with sodium amalgam (6), however, as shown in the figure, a closure body (2B) is placed in the other end opening (1b),
The other electrode (4B) supported by the niobium wire (8) and the glass solder molded body (5) are arranged and housed in an airtight container (not shown) such as a Pelzer. After exhausting the air, the glass solder molded body (5) is heated and melted in an atmosphere of the same kind of gas as the starting rare gas. (2B) The closing body (2B) and the niobium wire (8) are sealed, and the second sealing step is completed to complete one arc tube.

According to this method, it is possible to carry out the exhaust, the filling of the rare gas for starting, and the second sealing process in one continuous process, but on the other hand, the sealed sodium amalgam (6) is attached to the glass solder on the upper end side of the first seal. There is a drawback that the glass solder (5A) and sodium react with each other, resulting in a short life.

Furthermore, another manufacturing method shown in FIG.
) are connected to the electrodes (4A) and (4B) via the niobium tubes f3) and (3), respectively.
) are sealed with closure bodies (2A) and (2B) that support the
After filling the sodium amalgam (6) through the opening (3a) of the niobium tube (3), it is evacuated, and then the opening (3a) of each niobium tube (3), (3) is evacuated in a rare gas atmosphere.
, (3a) is a method of hermetically sealing. This method also has separate sealing and evacuation processes, which is inefficient, and the activated electrode emitter is exposed to air during the manufacturing process, causing deterioration. It has drawbacks such as increased cost due to the use of a niobium tube.

(Problems to be Solved by the Invention) As described above, conventional methods for manufacturing high-pressure sodium lamp arc tubes have drawbacks such as poor efficiency, short life, and increased costs.

Therefore, the present invention aims to eliminate the above drawbacks.

The purpose of the present invention is to provide a method for manufacturing a high-pressure sodium lamp arc tube that has good work efficiency, has a long life, and can be manufactured at low cost.

[Structure of the invention]

(Means for solving the problems) In the method for manufacturing a high-pressure sodium lamp arc tube of the present invention,
First, one end opening of a light-transmitting ceramic arc tube bulb is first sealed with a ceramic closing body through glass solder in a vacuum or rare gas atmosphere. At the same time, in this first sealing step, a niobium tube with an electrode supported at one end and sealed at the other end is sealed into the through hole provided in the closure body through glass solder. Next, sodium amalgam is sealed in a rare gas atmosphere, and after exhausting, the other end opening of the arc tube pulp is second sealed with a ceramic closed base via glass solder in an atmosphere of the same kind of gas as the starting rare gas. do. In this second sealing step, the niobium wire supporting the electrode is simultaneously sealed to the through hole provided in the closure body via glass solder.

(effect) With such a configuration, after the first sealing step.

Since the emitter coated on the electrode is not exposed to air, its characteristics are prevented from deteriorating, and the expensive niobium tube is only used to support one of the pair of electrodes, which reduces costs accordingly. Furthermore, since excess sodium amalgam sealed in the arc tube accumulates in the niobium tube, which is the coldest part, it is possible to prevent shortening of life due to reaction between sodium and glass solder. Moreover.

Not only can all processes be performed in the same device, but also the exhaust, charging of the starting rare gas, and second sealing can be performed in the same process, which has the advantage of improving work efficiency.

(Example) The present invention will be described in detail below based on an example shown in two drawings.

FIG. 1(A)-CI) is a vertical cross-sectional view showing a method for manufacturing an arc tube in the order of steps. (4) In the figure, (1) is an arc tube pulp made of a translucent ceramic such as alumina ceramic with open ends, (2A) is a closed body made of a ceramic such as alumina ceramic, and (3) is a niobium tube with the closed body Penetrates the center of (2 people).

One end supports an electrode (4A) coated with an activated emitter (not shown), and the other end is hermetically sealed. (5) and (5) are ring-shaped glass solder molded bodies, which are formed by compressing mixed powder of metal oxides such as alumina, calcia, magnesia, etc.

Fit the closing body (2 people) in the above arrangement into the opening (1a) at one end of the arc tube pulp (1), and heat the glass solder molded bodies (5), (5) in a vacuum or rare gas atmosphere. When melted and then cooled, (g) the one end opening (1a) of the arc tube pulp (1) and the closing body (2 persons) and the closing body (2 persons) and the niobium tube (3) are formed as shown in the figure. Each gap is hermetically sealed with glass solder (5A), and the first sealing process is completed.

Next, as is known, sodium amalgam (6) in excess of the amount that evaporates during lamp lighting is introduced into the arc tube pulp (1) in a rare gas atmosphere.

The arc tube pulp (1) in which the sodium amalgam (6) is retained in order to prevent the sodium amalgam (6) from being heated and evaporated and scattered in the next second earthen process.
The upper end of the first seal is held by a holder (7) equipped with a cooling mechanism (as shown in Figure 0).On the other hand.

The other end opening (1b) of the arc tube pulp (11) includes an alumina ceramic closing body (2B) and this closing body (2B).
A niobium wire (8) supporting the other electrode (4B) coated with an activated emitter at one end and a ring-shaped glass solder molded body (5) are placed through the arc tube bulb flll. After exhausting the gas, the glass solder molded body (5) is heated and melted in an atmosphere of the same kind of gas as the starting noble gas sealed in the arc tube, and then cooled (finally). As shown in the figure, the other end of the arc tube pulp opens. part (1b) and the obturator (2B)
), the gaps between the closing body (2B) and the niobium wire (8) are hermetically sealed with the glass solder (5A), and the above-mentioned starting rare gas is also introduced into the arc tube, completing the second sealing process. The luminous tube is completed.

Once the arc tube manufactured by this method is turned on, when the light is turned off (as shown in Figure 0, excess sodium amalgam (6) is accumulated inside the coldest part of the niobium tube (3) toward the tip. Therefore, the reaction between excess sodium amalgam (6) and glass solder (5A) is prevented,
Stable lifespan. In addition, since the activated emitter coated on the electrode is not exposed to air after the first sealing process, deterioration of the electron emission performance of the emitter can be prevented, and it is also better than niobium wire. The use of expensive niobium tubes, which are used in large quantities, is preferable from the point of view of cost because only one end is required. Moreover, not only can the entire process be performed within the same equipment, but also exhaust gas.

There is also the advantage in terms of work efficiency that the charging of the starting rare gas and the second sealing can be performed in one step.

〔Effect of the invention〕

As described in detail above, according to the present invention, characteristics deterioration due to exposure of the activated emitter of the electrode to air during manufacturing and shortening due to the reaction between the glass solder and the sodium amalgam in the sealing part can be avoided. Not only can you prevent the end of your life.

Cheap arc tubes can also be obtained by improving work efficiency and limiting the use of expensive niobium metal.

[Brief explanation of drawings]

j@ Show an explanatory diagram. (1)... Arc tube bulb, (2A), (2
B)・Intermediate・Occluded body. (3)... Niobium tube, (4A), (4B
)4...electrode. (5)...Glass solder molded body. (5A)...Glass solder. (6) Sodium amalgam.

Claims (1)

[Claims] A vacuum is applied to the gap between the opening at one end of the light-transmitting ceramic arc tube bulb and the ceramic closure, and the gap between the niobium tube that has passed through the closure and supports an electrode at one end and is sealed at the other end. Alternatively, a first sealing step of sealing via glass solder in a rare gas atmosphere, a step of sealing sodium amalgam in a rare gas atmosphere, and a step of evacuating the inside of the arc tube bulb, followed by the same type of starting rare gas. In a gas atmosphere, the gap between the opening at the other end of the arc tube bulb, the ceramic closing body, the niobium wire that passes through this closing body and supporting an electrode at one end, and the closing body is sealed via glass solder. A method for manufacturing a high-pressure sodium lamp arc tube, comprising a second sealing step.