JPH03110747A - Ultra violet ray mercury lamp - Google Patents

Abstract

PURPOSE:To prevent failures of coils, separation of welded parts, and adhesion of wastes, so as to increase fabrication yield by forming an electrode in such a way that the rear end section of an electrode coil is welded to an electrode pole with titanium solder. CONSTITUTION:An electrode coil 12 is fitted around an electrode pole 11 in advance, a titanium solder ring is fitted onto the rear end section of the electrode coil 12, then, the electrode is set up while allowing inert gas, for example, argon gas to flow in a heating furnace so that the electrode coil 12 is thereby welded to the electrode pole 11 with titanium solder 13. In this case, since the electrode does not come in contact with a heater within the heating furnace, the coil 12 will never fail. In addition, since titanium molten during heating flows into a gap between the efectrode pole11 and the rear section of the electrode coil 12 so as to weld them together, there is no need for welding the electrode therewith, whereas wastes are splashed away together with argon gas so that adhesion of wastes onto the electrode can be restricted. By this constitution, fabrication yield can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an ultraviolet mercury lamp used for photochemical reactions such as curing paints and resins using ultraviolet rays.

Conventional technology In recent years, ultraviolet curing technology for paints and resins has been put into practical use.
The main wavelength is 5 nm, and the wavelength is 303 nm.

BACKGROUND ART An ultraviolet mercury lamp made of quartz glass and having a stacked tube shape is known, which efficiently emits Φ ultraviolet radiation such as 313 nm in abundance. UV mercury lamps have been developed with various lengths taking into account the size of the object to be irradiated, but the input power per unit length of the emission length is 80 W/clI and 120 W/a.
ll is the mainstream.

The electrodes used in this type of ultraviolet mercury lamp have a structure similar to that of mercury lamps for general lighting. That is, an electrode coil made of a refractory metal is wound and fixed around an electrode rod, and the gap between the two is impregnated with an electron radioactive substance.
Furthermore, the tip of the electrode rod protrudes from the tip of the electrode coil so that the arc concentrates at the tip of the electrode during lighting. To fix the electrode rod and the electrode coil, the electrode rod is inserted into the electrode coil, and the rear end of the electrode coil is spot-welded to the electrode rod.

However, the problem to be solved by the invention is that it is necessary to adjust the welding voltage during spot welding. For example, if the welding force is too strong, a part of the welded electrode coil will break off. That is, the welding rod sticks to the electrode coil, and when the electrode rod is separated from the electrode rod, a portion of the electrode coil is damaged. On the other hand, if the welding force is weak, welding will occur. Further, there is also the problem that dirt adheres to the surface of the welded electrode coil regardless of the strength of the welding force.

The present invention has been made to solve these problems, and provides an ultraviolet mercury lamp that suppresses coil defects, welding defects, and dirt deposition, and improves the yield of the electrode process.

Means for Solving the Problems The ultraviolet mercury lamp of the present invention is one in which a starting rare gas and mercury are sealed in an arc tube equipped with electrodes at both ends.
The electrode has a structure in which the rear end of the electrode coil is welded to the electrode rod using titanium solder.

Function: An electrode having such a configuration is made as follows. In other words, an electrode coil is inserted into the electrode rod in advance, and a titanium brazing ring is inserted into the rear end of the electrode coil.
The electrodes are set while an inert gas such as argon gas is flowed into the heating furnace, and the electrode coil and electrode rod are welded together using titanium solder.

Therefore, since the electrode does not come into contact with the heater in the heating furnace, no damage to the coil occurs. Furthermore, the titanium melted during heating flows between the electrode rod and the rear end of the electrode coil and welds them together, resulting in spot welding and eliminating electrode welding. Moreover, since the dirt is scattered together with the argon gas, it is possible to suppress the adhesion of dirt to the electrodes.

Embodiment FIG. 2 is a front view of an ultraviolet mercury lamp which is an embodiment of the present invention. As shown in the figure, electrodes 2 and 3 are provided at both ends of a quartz glass arc tube 1 having an outer diameter of 23 days, and argon and mercury are sealed inside. The electrodes 2, 3 are each connected to a lead wire 9.10 via a metal foil conductor 7, 8 sealed in a crush seal 5.6.

FIG. 1 is an enlarged partially cutaway front view of an electrode used in such an ultraviolet mercury lamp. In the same figure, the diameter is 1.6+
A tungsten wire having a diameter of 0.7 mm is wound around an electrode rod 11 made of tungsten having a diameter of 0.7 mm to form an electrode coil 12, and the rear end of the electrode coil 12 is welded to the electrode rod 11 with a titanium solder 13. Electron radioactive material 1 is placed in the gap between the electrode coils 12.
4 is impregnated.

In the ultraviolet mercury lamp having the above configuration, the electrode 2.3 is made by welding the rear end of the electrode coil 12 to the electrode rod 11 with titanium solder 13, so the work of fixing the two is easier than in the past. It is extremely simple and electrode 2.
In addition to suppressing the adhesion of dirt to the electrode coil 12, it also eliminates damage to the electrode coil 12 and the welding of the electrode rod 11 and the electrode coil 12, which occur in conventional spot welding, resulting in improved yield. improves. Therefore, according to the lamp according to the embodiment of the present invention, the cost can be significantly reduced compared to the conventional lamp. In addition, since the electrode rod 11 and the electrode coil 12 are welded together with titanium solder 13, which is a difficult-to-melt metal, there is no risk of the titanium solder 13 melting even if the inside of the arc tube 1 becomes high temperature during lighting. do not have.

Based on the configuration of the above example, a 1 kW ultraviolet mercury lamp with an input per unit length of light emitting length of 80 W/(Ml) was manufactured and a lighting test was conducted. In addition, in order to compare with these, a 1 kW ultraviolet mercury lamp with a conventional configuration with the same input per unit of emission length was also fabricated and a lighting test was conducted.The results are shown in curve ■ in Figure 3. .As is clear from Figure 3,
When lit at the end of its life (1500 hours), the UV retention rate of conventional lamps was approximately 85% of the initial value.
In the lamp of the present invention, the ultraviolet output is approximately 90% higher than the initial value.
% can be maintained. Furthermore, it was confirmed that the lamp of the present invention was able to sustain stable discharge with little blackening of the inner wall surface of the arc tube near the electrodes.

As described in detail of the invention, the ultraviolet mercury lamp of the present invention is an ultraviolet mercury lamp in which a starting rare gas and mercury are sealed in an arc tube with electrodes at both ends, and the electrodes are formed by connecting an electrode coil to an electrode rod. Since the rear end is welded with titanium solder, unlike conventional methods, there is no need to adjust the welding voltage, and there is no loss of electrode coils, no welding, and no dirt adhering to the electrode coils, which simplifies the electrode process. This makes it possible to improve the yield of the electrode process, thereby reducing costs.Furthermore, as mentioned above, by eliminating the adhesion of dirt to the electrode coil, the UV retention rate is improved compared to conventional methods. It is something that can be done. Furthermore, since titanium solder, which is a difficult-to-melt metal, is used to weld the electrode rod and the electrode coil, even if the inside of the arc tube becomes high temperature while the lamp is lit, the lamp will not melt due to the heat. Further, titanium solder can exhibit an effect as a getter material.

[Brief explanation of drawings]

FIG. 1 is an enlarged partially cutaway front view of an electrode used in an ultraviolet mercury lamp which is an embodiment of the present invention, FIG. 2 is a front view of an ultraviolet mercury lamp which is an embodiment of the present invention, and FIG. FIG. 3 is a characteristic diagram of the ultraviolet retention rate showing a comparison between the lamp of the present invention and a conventional lamp. 2.3... Electrode, 11... Electrode rod, 1
2... Electrode coil, 13... Titanium wax.

Claims (1)

[Claims] An ultraviolet mercury lamp in which a starting rare gas and mercury are sealed in an arc tube equipped with electrodes at both ends, characterized in that the electrodes are formed by welding the rear end of an electrode coil to an electrode rod using titanium solder. UV mercury lamp.