JPS5810813B2 - Manufacturing method of low pressure mercury discharge lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a low pressure discharge lamp, such as a fluorescent lamp.

As is well known, mercury enclosed in a low-pressure discharge lamp, such as a fluorescent lamp, is excited during operation of the lamp.
It excites the phosphor coated on the wall of the lamp tube to emit light, and the amount of phosphor applied can not only shorten the luminous efficiency but also shorten the lifespan and significantly impair the appearance of the product. Therefore, mercury is indispensable for lamps, and at the same time, it is necessary to reliably seal a predetermined amount of mercury inside the lamp.

On the other hand, since mercury is a polluting substance, it is necessary to prevent the mercury from scattering and contaminating the surrounding environment during the lamp manufacturing process and when the lamps are disposed of. .

Therefore, especially when manufacturing a lamp, it is desired to weigh out the minimum amount of mercury necessary for the characteristics of the lamp, and to ensure that the entire amount of the weighed mercury is sealed within the lamp.

Recently, various methods have begun to be put into practical use to meet these demands.

One method is to press a mixed powder of a mercury compound or mercury alloy and a getter agent onto a metal plate, and control the amount of mercury based on the area of the crimped area, or to encapsulate weighed mercury in a small glass capsule. Attach the mercury supply structure made of molten metal to the electrode part of the lamp, and after the lamp exhaust treatment process is completed, destroy the mercury supply structure by heating etc. and take out the mercury necessary for lamp discharge inside the bulb. There is a way.

However, this method requires a new mercury supply structure to be installed on the electrode, which increases material costs, complicates the structure of the electrode part, and requires a heating process after the exhaust treatment process.
This point has been a bottleneck in production when trying to improve lamp manufacturing efficiency.

This invention was made in view of the above-mentioned circumstances, and provides a method for manufacturing a low-pressure discharge lamp that can reliably fill the lamp with the minimum necessary amount of mercury without increasing material costs or impeding productivity. It is intended to.

The details of the present invention will be explained below with reference to one embodiment shown in the drawings.

FIG. 1 shows a plan view of an apparatus in which the manufacturing method of the present invention is carried out, and FIGS. 2 to 7 show the manufacturing method of the present invention in the apparatus in the order of steps X, -Yl to X6-X6.
This is shown in a cross-sectional view.

First, as shown in FIGS. 1 to 3, in the valve mounting process A, both ends are coated with a thermionic emitting material (generally made of an alkaline earth metal composite carbonate).

Hereinafter, it will be simply referred to as an electrode material.

), and has an exhaust capillary 2 at one end.The valve 3 has a plurality of exhaust heads 5 arranged at equal intervals around the periphery of a turntable 4 that rotates intermittently. After the mercury is mounted through the mercury holder, the mercury is transferred to the mercury supply step B as the turntable 4 rotates.

In FIG. 3, the exhaust head 5 equipped with the above-mentioned valve 3 has a capillary mounting part 6 on the lower part to which the exhaust capillary tube 2 of the valve 3 is mounted, and an exhaust device (31, fourth Vacuum suction piping 7 connected to (shown in the figure)
and weighed mercury 1, which will be described later.
a drop hole 9 formed to allow the mercury 14a to fall into the valve 3 through the exhaust tube 2; and a movable ferromagnetic tube that opens and closes the drop hole 9. An electromagnet (37
6), a communication hole 11 that communicates the inside of the mercury reservoir cylinder 8 with the vacuum suction piping 7, a lid 12 that is provided on the upper part to be openable and closable and maintains the inside airtight. It consists of a lid driving device (not shown) that provides opening and closing motion to the lid 12.

When the exhaust head 5 reaches the mercury supply step B, the lid 12 is opened by the drive device.

Thereafter, a single mercury weighing and coating device 13 installed opposite to the exhaust head 5 weighs out the necessary minimum amount of mercury 14a to be sealed in the valve 3, and coats it with a chemically stable powder. The mercury is dropped into the mercury reservoir cylinder 8.

That is, the mercury weighing and covering device 13 consists of a mercury weighing device 15 and a mercury grain covering device 16. A mercury weigher main body 20 having a mercury dripping hole 19 that communicates with the mercury guide hole 18 , and a body portion 21 that is rotatably provided in the main body 20 and blocks communication between the mercury guide hole 18 and the mercury dripping hole 19 . A rotor 2 in which a concave portion 22 selectively facing the mercury guide hole 18 and the mercury dripping hole 19 is formed in the body portion 21.
3, and a rotor drive device 24 that provides rotational motion to the rotor 23, the latter mercury grain coater 16 coated with a layer 25 of chemically stable metal oxide powder such as zirconium oxide or aluminum oxide. A rotatable funnel-shaped body 28 having an inner inclined surface portion 26 formed therein and a mercury particle introduction hole 27 formed in the center thereof, and a rotatable funnel-shaped body 28 having an inner inclined surface portion 26 formed at the center thereof, and a lower end of the inner inclined surface portion 26 of the mercury droplet hole 19. and a holder 29 that holds the lower end of the mercury introduction hole 27 above the exhaust head 5 so as to closely oppose each other, and a funnel-shaped body drive device 30 that provides rotational movement to the funnel-shaped body 28. has been done.

The recess 22 of the rotor 23 is connected to the mercury guide hole 18.
When rotated to face the mercury dripping hole 19, the mercury particles 14 accumulated in the recess 22 fly out from the recess 22, pass through the mercury dripping hole 19, and flow into the oxidized metal rice of the rotating funnel-shaped body 28. The mercury is dropped onto the layer 25 and further rolled down on the slanted layer 25 to be sufficiently coated with the oxidized metal powder, and then introduced into the mercury reservoir tube 8 of the exhaust head 5 through the mercury introduction hole 27.

The exhaust head 5 receives the supply of the mercury particles 14a, and the lid body 1
2 is closed by the lid driving device.

When the exhaust head 5 equipped with the valve 3 in this manner goes through a mercury supply step B in which mercury particles 14a weighed in a certain amount and coated with chemically stable powder are accommodated in the exhaust head 5, As shown in FIG. 4, an exhaust process C is started in which the gas contained in the mercury particles 14a and the impurity gas inside the bulb 3 are continuously exhausted by the exhaust device 31, and the fluorescent substance coated inside the bulb is The electrode material is transferred to a valve heating step for thermal degassing and an electrode treatment step E1 for first decomposition of the electrode material.

In this electrode treatment step E1, that is, when the impure gas pressure in the valve 3 is reduced to 4 Torr or less and the valve temperature is 300° C. or less, the electrode treatment device 32 consisting of the constant current circuit 23 is used to remove the first electrode material. Perform disassembly process.

Here, the reason why the impure gas pressure in the bulb 3 was set to 4 Torr or less and the bulb temperature was set to 300°C or less is that if these ranges are exceeded, the gas released from the air remaining in the bulb 3 and the fluorescent substance Water, carbon dioxide, oxygen, -
Due to oxidizing gases such as carbon oxide, the tungsten wire forming the filament coil (not shown in the electrode 1) itself is oxidized, or a large amount of intermediate layer compounds are generated at the interface between the tungsten wire and the electrode material. This is because too much is produced, impairing lamp life and blackening performance.

The valve 3 is then heated to 400'C to 450'C in a heating furnace 40.
℃, the fluorescent substance is heated and degassed, and the bulb 3 is further cooled and the impurity gas inside the bulb 3 is further reduced.After the latter part of the bulb heating process, the process moves to the electrode treatment process E2 provided in D2. , the above-mentioned electrode processing device 32
A second decomposition process of the electrode material is performed by a device 32 formed in the same manner as described above, and a highly active electrode material is formed.

Then, as shown in FIG. 5, a flash exhaust step F is carried out at an appropriate position in the second electrode treatment step E2 to promote the discharge of impurity gas.

That is, at almost the peak of the gas slightly released by the second decomposition process, an inert gas such as argon gas is injected into the several Torr valve 3 by the inert gas filling device 34, and then the impurity gas and its inert gas are injected into the several Torr valve 3. The mixed gas is discharged in a region where the effective pumping speed of a vacuum pump (not shown) is large.

In this way, if most of the decomposed gas released from the electrode material is released in the first half of the exhaust process C, and in the second half, the gas re-adsorbed by the electrode material and the remaining part of the decomposed gas are released, then the second Since the impure gas pressure within the valve 3 can be kept low during electrode processing, the injection pressure and number of injections of inert gas can be reduced when performing flash exhaust.

Next, the valve 3 is located at a position where it is connected to the sealed gas filling device 35 which is disposed at a position where communication with the exhaust device 31 is cut off;
That is, the process is moved to mercury and filler gas filling step G.

(Fig. 6) The gas filling device 35 in this step G stores a certain amount of the gas such as argon gas sealed in the valve 3 so that a predetermined gas pressure is reached after filling the valve 3. A storage container 36, and opening and closing of this container,
It also includes a solenoid valve 38 that is interlocked with the operation of an electromagnet 37 that attracts the metal ball 10 inside the exhaust head 5.

When the metal ball 10 that was blocking the drop hole 9 is sucked upward by the operation of the electromagnet 37, the mercury particles 14a stored in the mercury reservoir tube 8 in the exhaust head 5 are removed from the drop hole 9 and the drop hole. It falls into the exhaust thin pipe 2 which communicates with the exhaust pipe 9.

At the same time, a predetermined amount of argon gas flows from the gas filling device 35 through the exhaust head 5, and is sealed into the bulb 5 together with the mercury particles 14a while urging the mercury particles 14a to fall.

Immediately thereafter, a process H is performed in which the exhaust thin tube 2 is sealed off by the burner 39, and the exhaust work is completed.

(FIG. 7) In the manufacturing method comprising the steps described above, the amount of mercury grains 14a weighed by the mercury weigher 15 and to be enclosed in the fluorescent lamp 41 is a chemically stable powder. By being coated with this material, the so-called adhesion wetting phenomenon that tends to adhere to other objects is alleviated, and since argon gas is simultaneously filled when falling into the valve 3, the falling energy is applied, so that the exhaust gas is Adhesion to the inside of the head 5 and the exhaust tube 2 can be prevented.

In addition, the electrode material decomposition treatment steps E, , E2 are carried out separately in the first stage D1 and the second stage D2 of the bulb heating step.
Most of the decomposed gas is released during the decomposition process in the former stage D1, and the amount of gas released during the electrode treatment performed in the latter stage D2 is greatly reduced. The effect of flash exhaust can be demonstrated more efficiently.

Therefore, in the fluorescent lamp 41, weighed mercury particles 1
The entire amount of 4a can be extracted as mercury required for discharging the fluorescent lamp 41 in a shorter time.

The inventors used the method of this invention to inject and exhaust a 40-watt fluorescent lamp with an exhaust capillary on one side at a pressure of 6 Torr in the bulb during flash exhaust, and repeated this process twice to achieve mass production. When manufactured,
The amount of mercury sealed in the lamp is approximately 1 mercury when weighed.
It was confirmed that the time required for the evacuation work was reduced by about 30% compared to an example in which flash evacuation was not performed.

Note that this invention is applicable not only to fluorescent lamps but also to other discharge lamps,
Of course, it can also be applied to germicidal lamps, for example.

Furthermore, in the above embodiments, a vertical type exhaust system has been described, but of course a horizontal type may also be used.

The first invention of this application covers a plurality of exhaust heads with a stable powder of mercury weighed by a common mercury weigher, and then injects this into the exhaust heads, and performs an electrode treatment process in the front and rear stages. The above-mentioned coated mercury is sealed in the bulb along with the filler gas, and there is no need to install new parts in the bulb or equipment to process the parts, thus reducing lamp material costs. It is possible to reliably encapsulate the minimum amount of mercury in the lamp without increasing productivity or hindering productivity, and its industrial value is enormous.

In addition, the second invention of this application has, in addition to the structure of the first invention, a step of flash exhausting corresponding to the subsequent electrode processing step, so that the effect of the first invention can be improved. In addition, sufficient flash exhaust can be achieved simply by using a general inert gas instead of mercury.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an embodiment of a fluorescent lamp manufacturing apparatus for explaining the manufacturing process of the present invention, FIG. 2 is a cross-sectional view of FIG. Figure 4 is a cross-sectional view of X2-Y2 in Figure 1, Figure 4 is a cross-sectional view of X3-Y3 in Figure 1, Figure 5 is a cross-sectional view of X4-Y in Figure 1, and Figure 6 is a cross-sectional view of X5-Y in Figure 1.
5 is a sectional view, and FIG. 7 is an X6-Y6 sectional view. In the figure, 1 is an electrode, 2 is an exhaust tube, 3 is a valve, 4 is a turntable, 5 is an exhaust head, 13 is a mercury weighing and coating device, 15 is a mercury weigher, 16 is a mercury particle coating device, 31 is an exhaust device, 32 is an electrode processing device, 34 is an inert gas filling device, 35 is a sealed gas filling device, A is a valve installation process,
B is the mercury supply process, C is the exhaust process, D is the valve heating process, El is the electrode treatment process (the first part of the bulb heating process, E2 is the electrode treatment process (after the second part of the valve heating process), F is the flash exhaust process, G 1 is the mercury and filler gas charging process, and H is the exhaust capillary sealing and cutting process. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A step of attaching a valve to a plurality of exhaust heads provided on the periphery of the turntable and communicating with an exhaust device via an exhaust thin tube, and a step of attaching a valve to a plurality of exhaust heads provided at a predetermined position and communicating with an exhaust device. mercury weighed by a common mercury weigher is coated with a chemically stable powder and then introduced into the exhaust head, and the exhaust head and valve that have gone through both of the above steps are started to be exhausted. A process of heating and degassing the fluorescent material coated inside the bulb, and an electrode provided inside the bulb, which separates this heating and degassing process into a front stage and a rear stage while exhausting the inside of the bulb. a step of performing electrode treatment, and a step of dropping the mercury introduced into the exhaust head into the valve, filling the valve with gas, and immediately thereafter sealing off the exhaust capillary. A method of manufacturing a low pressure discharge lamp having the following. 2. The process of attaching valves to multiple exhaust heads installed around the periphery of the turntable and communicating with the exhaust device via exhaust capillaries, and the mercury weighed by a single mercury weigher installed at a predetermined position. A process of coating the powder with a chemically stable powder and then introducing it into the exhaust head, and starting exhaustion of the exhaust head and bulb that have gone through both of the above processes, and heating the fluorescent substance coated inside the bulb. a step of degassing, a step of performing electrode treatment on the electrode provided in the valve by dividing this heating degassing step into a front stage and a rear stage while exhausting the inside of the valve; During the electrode treatment process that is carried out after the latter part of the gas process, an inert gas is injected into the valve to promote the removal of impurity gas in the valve, and after these processes are completed, the exhaust head is removed. A method for manufacturing a low-pressure discharge lamp, comprising the steps of dropping mercury introduced into the bulb into the bulb, filling the bulb with gas, and immediately thereafter sealing off the exhaust capillary.