JPS6247931A - Rare gas sealing method for tubular bulb - Google Patents

Abstract

PURPOSE:To make the extent of sealing gas into the specified desired one independent of the inner volume of tubular bulb, by decompressing the sealing gas pressure of rare gas inside the tubular bulb directly so as to cause it to become the desired pressure after the rare gas of higher sealing has than the desired sealing gas pressure is led into the tubular bulb. CONSTITUTION:Rare gas is sealed in a tubular bulb 1 from a rare gas sealing device 5 with higher sealing gas pressure than the desired sealing gas pressure through holes 7 and 11 of a center valve installed between the tubular bulb 1 and the rare gas sealing device 5. A vacuum pump 15 connected to a hole of the center valve via a guide tube and a solenoid valve 13 is operated whereby the sealing gas pressure of rare gas inside the tubular bulb is decompressed, and gas pressure inside the guide tub e corresponding to the sealing gas pressure inside the tubular bulb is detected by the pressure sensor 16 connected to this guide tube. And, on the basis of this detection signal, the solenoid valve 13 is closed when the gas pressure inside the guide tube has reached to the speci fied decompressed value, having the rare gas inside the tubular bulb set to the desired sealing gas pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for filling a tube with a rare gas, such as a fluorescent lamp, for automatically controlling the pressure of the rare gas sealed inside the tube.

Conventional Technology In general, fluorescent lamps are filled with a rare gas such as argon gas, but the pressure of this filled gas has a great effect on the characteristics of the fluorescent lamp, so management of the filled gas pressure is extremely important. . A common method of controlling this type of filled gas pressure is to extract one fluorescent lamp out of every several thousand lamps and measure and manage the filled gas pressure using a destructive method. Here, the steps before and after the noble gas filling will be explained.

The fluorescent lamp that has undergone the usual process is heated in the usual manner through a pair of center bulbs having multiple through holes, and the air inside the lamp is evacuated with a vacuum pump to remove the electrodes. After activation, the lamp is generally filled with about 10 q of mercury and several Torr of rare gas such as argon gas, and finally the exhaust capillary is sealed by heat.

However, the center valve used here is generally of an intermittent drive type, and Figure 3 AND shows the main part of the connection path between the center valve and the fluorescent lamp near the rare gas filling system. The so-called center valve has a fluorescent lamp 1 connected to a hole on the rotating side 2 of the center bulb, a vacuum pump 4 connected to a hole on the stationary side 3 of the center bulb, and both holes communicating with each other. shows the fixed position state. Figure B shows the transition from the normal position state to the next normal position state (
A solenoid valve 6 and a rare gas cylinder 6 are connected to the fixed side 3 of the center valve. This solenoid valve 6 opens when the center valve is in the normal position,
The timing is adjusted by a controller (not shown) so that the circuit is closed by the time it is indexed. Therefore, when the center valve is in the normal position, rare gas is accumulated in the space formed between the hole on the fixed side 3 of the center valve and the solenoid valve 6, and the next instant, as shown in FIG. 3B, When the holes on the rotating side 2 and the holes on the stationary side 3 of the center bulb communicate with each other, the rare gas in the space will be introduced into the fluorescent lamp 1 connected to the rotating side 2 of the center bulb. FIG.
Since there is no hole in the fluorescent lamp 1 and the hole in the fixed side 2 is closed, the rare gas in the fluorescent lamp 1 is trapped. In addition, in Figure C, approximately 109 mercury is dropped into the fluorescent rung 1 using a common mercury introducing device (not shown), and the exhaust capillary (not shown) provided at the end of the mercury is sealed. be done.

Problems to be Solved by the Invention As mentioned above, the conventional method for controlling the gas pressure filled with rare gas in tubes is to extract one fluorescent lamp out of every several thousand lamps and measure and manage it using a destructive method. However, there is a limit to the reliability of the applied solenoid valve. For example, if the solenoid valve malfunctions after measuring the filled gas pressure, the Or, there was a potential problem in which all or some of the tube products produced before the accident was discovered were defective.

Fig. 3 p is a schematic diagram of the main part shown in Japanese Patent Application Laid-Open No. 156676/1983 as a proposal for solving the above problem, and shows the gas filling position (position corresponding to Fig. 3 B) or the next position. In this method, the pressure sensor 7 is installed in the fixed side circuit of the center valve at a fixed position corresponding to the position. However, in the case of this method, the leaking head on the rotating side 2 of the center valve or the head connected to the leaking fluorescent lamp 1 may be located at the gas filling position (the state shown in Figure 3B) or the pressure sensor. When the valve reaches the provided position (FIG. 3D), impure gas such as air is introduced into the space on the fixed side 3 of the center valve. As a result, not only the fluorescent lamp connected to the head, but also several or more fluorescent lamps produced subsequently are filled with impure gas such as air, and the head or A major drawback is that a leak failure in a fluorescent lamp can result in the failure of several or more products.

The present invention was made in order to eliminate these conventional problems, and it is a tube that eliminates malfunction accidents such as the solenoid valve not opening when filling rare gas, and the negative effects caused by leaks from the head etc. The present invention provides a method for encapsulating a rare gas.

Means for Solving the Problems The method of filling a tube with a rare gas according to the present invention is to fill a tube with a rare gas from the rare gas filling device into the tube through a hole in a center valve provided between the tube and the rare gas filling device. A first step of filling the rare gas at a filling gas pressure higher than the desired filling gas pressure, and O.
By operating a vacuum pump connected to the hole of the center valve through a conduit and a solenoid valve, the pressure of the rare gas filled in the tube is reduced, and the pressure of the gas filled in the tube is reduced. A pressure sensor connected to this conduit detects the gas pressure in the conduit corresponding to the desired sealed gas pressure, and based on this detection signal, when the gas pressure in the conduit corresponding to the desired sealed gas pressure reaches a predetermined pressure reduction value. The method is characterized by comprising a second step of closing the electromagnetic valve to bring the rare gas in the tube to a desired gas pressure.

Function: In the method for filling a tube with rare gas according to the present invention, in the first step, a rare gas having a sealing gas pressure higher than the desired sealing gas pressure is introduced into the tube, and then in the second step, the rare gas is directly introduced into the tube. Since the pressure of the sealed rare gas is automatically reduced to a desired pressure, the pressure of the filled gas becomes a constant desired pressure regardless of the internal volume of the tube. In addition, if a solenoid valve malfunctions in the second process, a specific head on the rotation side of the center pulp is leaking, or the head with a bulb leak enters the second process. Even if the solenoid valve is inoperative, the inoperable state of the solenoid valve can be quickly discovered because the pressure sensor constantly detects the pressure of the gas sealed inside the tube.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1A to 1D are explanatory diagrams in which main parts of the connecting path between the center pulp and the sealing tube in the vicinity of the rare gas filling system of the fluorescent lamp according to the present invention are expanded and developed.

The process when each head clears the index in the order of A, C, and D in the same figure will be explained below.
A fluorescent lamp 1 is respectively connected in the usual manner to the rotating side 2 of the center bulb.

Figure A shows the fixed position state immediately before the rare gas is sealed into the fluorescent lamp 1, and a vacuum pump 4 is connected to the stationary side 3 of the center pulp through a conduit 8. Therefore, in the same figure, the air, etc. in the fluorescent lamp 1 is passed through the conduit 6, the holes 7.11 on the rotating side 2 and the fixed side 3 of the center bulb, and the vacuum pump 4 through the conduit 8. Exhausted. Figure B shows the intermediate position state from the above-mentioned figure A to the next regular position, that is, the position corresponding to figure C.
1, a variable-type leak pulp 9 and a rare gas cylinder 6 such as argon gas are connected through a conduit 10. Note that a pressure gauge (not shown) is connected to the rare gas cylinder 6. Therefore, in the fixed position state of the rotation side 2 of the center pulp,
The rare gas in the rare gas cylinder 6 is led to the variable-shaped leak pulp 9 through the conduit 1o, and further to the space created between the leak pulp 9 and the sliding surface of the rotating side 2 of the center valve, that is, the fixed side of the center pulp. A certain amount of rare gas with a sealed gas pressure higher than the desired pressure remains in the hole 11 of No. 3.

On the other hand, at the intermediate position where the rotating side 2 of the center pulp is indexed, when the hole γ and the hole 11 communicate with each other, the rare gas in the above-mentioned space is sealed into the fluorescent lamp 1, and then the center bulb is moved to the fixed position. The state becomes the state shown in FIG. In the same figure C, the fixed side 3 of the center valve
A vacuum pump 15 is communicated with the hole through a conduit 12, a solenoid valve 13, and a conduit 14. Further, the conduit 12 is provided with a variable reactance type pressure sensor 16 using a diaphragm. The pressure signal of this pressure sensor is sent to an amplifier 17.
The control circuit 18 can control the opening and closing of the solenoid valve 13. The timing of each component in this case will be explained below using FIG. 2. In FIG. 2 ANC, the horizontal axis shows time, and the vertical axis shows the state of each component.

In the same figure A, H is the movement of the rotation side 2 of the center pulp.
L indicates an assisting state, and L indicates a stopped state. Figure B shows the shift pulse for adjusting the timing to open and close the rotation side 2 of the center valve and the solenoid valve 13, Figure C shows the open/close state of the solenoid valve 13, and Figure C shows the change in pressure inside the conduit 12. show. Here, the state of the rotation side of the center valve (Figure 2), the state of the shift pulse (B of the same figure), and the timing of opening the solenoid valve change regularly according to a preset index. The timing of closing the solenoid valve depends on pressure changes within the fluorescent lamp 1. That is, in FIG. 1C, the solenoid valve 13 is controlled to close when the value of the detection signal of the pressure sensor 16 matches the preset desired pressure of the filling pressure inside the fluorescent lamp 1. It is said that In this case, the fill gas pressure in the fluorescent lamp 1 corresponds proportionally to the gas pressure in the conduit 12, and in the method according to the invention a pressure sensor 16 connected to the conduit 12 measures the gas pressure in this conduit. By detecting this, the pressure of the gas filled inside the fluorescent lamp 1 is indirectly measured. Therefore, for example, if the volume of the fluorescent lamp 1 changes, the pressure of filling the rare gas into the fluorescent lamp 1 at the position corresponding to the intermediate position between the figure 1 and the figure C will naturally change. . However, the gas pressure in the conduit 12 shown in FIG. When the gas pressure in the conduit 12 reaches a predetermined pressure reduction value, the electromagnetic valve 13 is closed, so that the gas pressure in the fluorescent lamp 1 is always constant. The rotating side 2 of the center valve is then indexed into the next home position, ie the first position. In the figure, no hole is located on the stationary side 3 of the center valve that corresponds to the hole 7 on the rotating side 2 of the center valve. Therefore, in the first diagram, the inside of the fluorescent lamp 1 is filled with argon gas, and about 1 oz. of mercury is dropped by a conventional method (not shown) to seal the exhaust capillary.

DETAILED DESCRIPTION OF THE INVENTION As described above, the method of the present invention includes supplying a desired rare gas from the rare gas filling device into the tube through the hole in the center valve provided between the tube and the rare gas filling device. a first step of filling the tube with a filling gas pressure higher than the filling gas pressure of the tube, and filling the rare gas in the tube by operating a vacuum pump connected to the hole of the center valve via a conduit and a solenoid valve. The gas pressure is reduced, the gas pressure in the conduit corresponding to the sealed gas pressure in the tube is detected by a pressure sensor connected to this conduit, and based on this detection signal, the gas pressure in the conduit corresponding to the desired filled gas pressure is detected. The method includes a second step of closing the electromagnetic valve when the gas pressure in the conduit reaches a predetermined pressure reduction value to bring the rare gas in the tube to a desired sealed gas pressure. Therefore, according to the present invention, when the solenoid valve is operating normally, when the pressure of the rare gas sealed in the tube is reduced, the pressure decreases from the value indicated by the pressure sensor as the vacuum pump operates. However, if the solenoid valve does not open due to an accident and the rare gas is not sealed in the tube, it is necessary to reduce the pressure. Since the reading from the hourly pressure sensor shows zero from the beginning, any malfunction of the electromagnetic valve can be quickly detected, and the occurrence of defective bulbs can therefore be minimized. Furthermore, according to the present invention, if a leak occurs in the bulb or head, even if the vacuum pump is activated during depressurization, impure gas such as air will enter the interior through the leak, causing the pressure sensor to Since the leakage does not decrease, it is easy to know that there is a leak in the tube, and this prevents the production of many defective tubes. In addition, in the conventional method, a certain amount of rare gas was sealed in the tube in advance to achieve the desired pressure, which caused variations in the pressure of the filled gas due to fluctuations in the inner volume of the tube. , according to the invention:
With the above configuration, regardless of the internal volume of the tube,
It is possible to always set the gas pressure of the rare gas in the tube constant.

[Brief explanation of the drawing]

Figure 1-D is a process diagram of a method for filling a tube with rare gas, which is an embodiment of the present invention, and Figure 2 is a diagram showing the movement and stop state of the rotation side of the center valve in the embodiment of the present invention.
Figure B also shows the rotation side of the center valve and shift pulses for timing adjustment to open and close the solenoid valve, Figure C
3A and 3B are diagrams showing the opening and closing states of the electromagnetic valve, respectively, and diagrams showing the state of gas pressure in the conduit. FIGS. 3A to 3D are process charts of a conventional method for filling a rare gas into a tube. 1...Fluorescent lamp, 2...Rotating side of the center valve, 3...Fixed side of the center valve, 4, 15...Medium vacuum pump, 5... ...Rare gas cylinder, 7.11...hole, 12.14...
... Conduit, 13 ... Solenoid valve, 16 ...
pressure sensor. Name of agent: Patent attorney Toshi Nakao and one other person E--] r9 lamp Figure 2 bell 77 (v) → B tan 1 (4 h) No

Claims (1)

[Claims] A first step of filling the rare gas from the rare gas filling device into the tube at a filling gas pressure higher than a desired filling gas pressure through a hole in a center valve provided between the tube and the rare gas filling device. and, by operating a vacuum pump connected to the hole of the center valve via a conduit and a solenoid valve, the gas pressure of the rare gas in the tube is reduced to correspond to the gas pressure in the tube. A pressure sensor connected to the conduit detects the gas pressure in the conduit, and based on this detection signal, the electromagnetic Close the valve,
A method for filling a tube with a rare gas, comprising a second step of bringing the rare gas in the tube to a desired pressure.