JPS58102431A - Manufacturing method of electrode for compact metal vapor discharge lamp - Google Patents

Abstract

PURPOSE:To prevent the generation of cracks in a sealed section, stabilize the quality of the captioned electrode, and facilitate its handling by alternately and continuously winding both fine and coarse winding sections forming a coil, and after, cutting the coil section in a preset length at the coarse winding section, fusing and burring a core end that is sealed at the sealed section. CONSTITUTION:A core 10 forming an electrode shaft 1 is composed of for example, W wires of 0.18mm. in diameter or the like. A coil strand 11 consisting of W wires of 0.10mm. in diameter, that is, the fine winding section 11 forming an electrode coil section 2 and a coarse winding section 12 that is more coarsely wound than this fine winding section are continuously and alternately wound around said core 10. The coil section is cut in a preset length at this coarse section and the coarse winding section 12 left on the external surface of the core 10 is removed using nippers (pliers) and then a burr is removed by flame-spraying an end that is connected to a metal foil conductor thermally or chemically, for instance, by means of laser, plasma, or the like. As a result, the quality of the captioned electrode can be stabilized and the generation of the cracks in the sealed section can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing small electrodes used in small metal vapor discharge lamps with a % [1 OOW or less].

Technical Background of the Invention In recent years, from the standpoint of energy saving, a small metal halide lamp with high efficiency and high color rendering has been desired as an alternative to the AM light bulb, which has been widely used as an indoor light source for general households. So far, the development of large metal halide lungs is limited to 100W or more. As a metal halide lamp that can replace incandescent light bulbs for general private gardens, 10
A size of 0W or less, especially 20 to 7DW class, is considered optimal.

By the way, one of the things that greatly influences the characteristics of small metal halide lamps is the electrode, and the size of the electrode has a large effect on lamp efficiency, color rendering, startability, turn-off characteristics, longevity* characteristics, etc. be.

In general, the electrodes of medium to large metal halide lamps (fttkb) and high pressure metal vapor discharge lamps are basically constructed by winding an electrode coil around an electrode shaft, as shown in Fig. 1 (4) to q. Most of them are as follows. In other words, Figure 1 (
In the case of 4), the pigeon-wound electrode coil part 1 is wound around the electrode 1, and in the case of 4) in Fig. 1, the electrode shaft 1 is wound with a double-layered electrode coil part 1, as shown in Fig. 1. 0 has an electrode 4 made of a double coil wound around an electrode shaft 1.

Small metal halide lamps of 100W or less basically use electrodes with the same structure as described above, but in small metal halide lamps of 100W or less, the re-ignition voltage at startup depends on the electrode axis 10 axis diameter d. It has been confirmed through experiments by the inventor that there is a large relationship between Q shows the relationship between the shaft diameter d of the electrode shaft 1 in the lamp and the restriking voltage, and as can be seen from this figure,
．． For the low rung, it is necessary to use an electrode shaft 1 with a shaft diameter d of 0.3 cm or less, and from this, 10
In the case of a 0W droplet lamp, the diameter of the electrode shaft 1 is further 0.
．． It is easy to understand that 3) also needs to be made smaller.

By the way, in the electrode of a conventional 400W class metal halide lamp, tungsten or tungsten containing thorium oxide ('rho) with a shaft diameter d of about 0.7 to 0.9 is used as the electrode shaft 1. A tungsten wire with a wire diameter of 0.3 to 0.6- is attached to the electrode shaft 1 like this! t
The fW(A) part or the electrode coil part 2 or #'11 is wound in a single layer or in multiple layers. 2 or S
This method of manufacturing electrodes can be adopted because the electrode shaft 20 has a large diameter. However, in the above-mentioned rung of 100 W or less, the shaft diameter of the electrode shaft 1 is 0.3 mm or less, which is extremely thin, so the pre-fabricated electrode coil part 2 or 1
It is extremely difficult to insert the electrode shaft 1 into the tube. For example, in the case of a 40W metal halide lamp, the shaft diameter d of the electric aS1 is between 0.15 and 0.15cm in relation to the above-mentioned restriking voltage.
The coil wire F of the electrode coil part 2 should be about 2 cm.
A wire diameter of the order of iO,l must be used.

Problems with the Background Art In the case of such a small-sized electrode, even if you try to insert the electrode shaft 1 into the prefabricated electrode coil part 2, the electrode shaft 1 is thin and the normal electrode coil part j (1) Coil inner diameter Since the diameter of the electrode shaft 1 is slightly smaller than the outer diameter of the electrode shaft 1, it cannot be inserted smoothly, causing problems such as the electrode shaft 1 being bent or the coil pitch being out of order. Since both the coil portions 2 are small, they are too large to be handled as me, making them unsuitable for mass production. Purpose of the Invention The present invention was made based on these circumstances, and its purpose is to Even electrodes with an electrode axis of 0.3- or less are suitable for mass production, have stable quality, and are not harmful to handle. It is an object of the present invention to provide a method for manufacturing an electrode for a small metal vapor discharge lamp that prevents the occurrence of such occurrence.

Summary of the Invention In other words, the present invention involves winding a long core wire alternately and continuously in densely wound portions and sparsely wound portions, which appear as coil portions, and cutting this into a predetermined length at the loosely wound portion. A small electrode is obtained by cutting off this loosely wound portion over a predetermined length, and then removing it by thermally or chemically melting at least the end of the core wire that is sealed on the sealing part side. A temple with a hammer.

EMBODIMENT OF THE INVENTION An embodiment of the present invention will be described below with reference to FIG. 3 and the subsequent drawings.

Figures 3 to 5 show the method of manufacturing electrodes for 40W class metal halide lamps in order.
indicates the core wire that becomes electrode @1, for example, the diameter is 0.18
Constructed from simple tungsten wire. The above core wire 10
A coil wire 11 made of tungsten wire with a diameter of 1 fCd of 0.1 square meters is wound as follows. In other words, for electrodes, in addition to the diameter of the electrode shaft, the diameter of the coil wire, and the form of the electrode coil (single-layer winding, double-layer winding, double coil, etc.), the bis of the electrode coil.

H. The length L1 of the electrode shaft, the protrusion height L' of the electrode shaft from the coil part, the length L3 of the electrode coil part, etc. are determined as optimal setting values. In this embodiment, a single-layer coil part is used. To explain the TIG, the core @ 10 has a densely wound part 11 which becomes the electrode coil part 2, and a loosely wound part 12 which is also loosely wound (skip-wound) than this densely wound part 11. Alternating Kt! fold. The tightly wound portion 11 has a predetermined width and a predetermined length 1. In this case, the dense part 11 does not necessarily mean that the coil R and the KIF are connected to each other. The above-mentioned Mitsumaki Iku 11 also refers to the 9th part by enlarging its bi and chi.

The length S of the densely wound portion 11 is the coil length 1. and the length t of the loosely wound part 12, #it, WL-t.

is set to . Note that this solid SO method can be easily manufactured using a known manufacturing machine for coil filaments for incandescent light bulbs. As shown in FIG. 3, the nine-core WIIO is wound onto a spool (h, not shown).

Next, the core a1o as shown in FIG. In order to improve its properties, it is immediately corrected by applying tensile force while passing it through a hydrogen furnace at about 90°C, for example.

When such straightening is completed, the electrode is cut into pieces each having a length L at the exit of the hydrogen furnace, for example, to obtain a semi-finished product as shown in FIG. In the semi-finished product cut in this way, the core wire 1o, which becomes the electrode shaft, protrudes from the tightly wound portion 11 by tl, and the loosely wound portion 1i 12.12 is formed on the outer periphery of the core wire 1o other than the tightly wound portion 11. Remaining Next, the loosely wound portion ix remaining on the outer periphery of the core wire 10,
If you cut xz with a knife or cutter, the core wire will be 10.
becomes the electrode shaft 1, and the tightly wound portion 11 becomes the electrode coil portion 2. Note that since the coil wire in the coil portion 2 is thin, the winding force around the electrode shaft 1 is weak and the position may shift, so in the state of No. 41ii or the state of FIG. or lede f
What is necessary is to fix it to the electrode shaft 1 by li contact or the like.

In this way, an electrode similar to that in Part 1 (a) can be produced, but the steps in Figures 3 to 5 can all be automated, so an electrode axis of 0.3 mm or less can be produced. Even the amount i! It is suitable for use and easy to manufacture.

By the way, the piezo electrode V manufactured by the above method is connected to a metal foil conductor #O made of a deden foil or the like as shown in No. When the lamp was successfully sealed to the sealing portion 62 and turned on, cracking was observed starting from the proximal end of the electrode shaft 1, as indicated by X in Figure #16. This cracking progresses over time while the lamp is lit, and eventually causes damage to the heater and bulb 61.

The inventor investigated the cause of this problem and discovered that the cause was the "bap" formed at the end of the electrode shaft 1 during cutting.

Since the conventional electrode shaft 1 is manufactured in advance separately from the electrode coils 2 and 3, a large number of the electrode shafts 1. However, the piezoelectrode F manufactured by the method shown in FIGS. 3 to 5 cannot be subjected to tampling treatment because the electrode coil portion 2 will be damaged by tampling treatment.

The present inventor has completed this assembly as shown in Fig. 5, and removed at least the m part of the piezo electrode V on the side connected to the metal foil conductor σO by thermally and chemically melting the metal foil conductor σO. Sujin and Kyop were solved.

Thermal treatments include Rede (CO, Rede, YAG Rede, etc.), electron beam, Dera, e! A method of irradiating the end of the electrode shaft 1 with a high-energy beam such as thermal spraying to melt it in a short time, or chemical melting, crushing the end of the electrode shaft 1 in aqua regia etc. In this example, as shown in FIG. 7, an IO method using a radar beam is shown. In FIG. 7, 10 indicates CO
, Rade oscillator, and 11Fi condenser lens. CO! Rede has a wavelength of 1000 m, and is usually reflected by metals, so it is inefficient for processing, but it can provide a large output, so it is suitable for melting small fields in a short time as in the present invention. There is. C02 radar is irradiated onto gIIA- using a condensing lens 11 with a beam diameter of a few centimeters, about the diameter of the electrode axis 10. For example, for a 0.3-diameter tungsten electrode shaft 1, it is 350 WOCO.

When the radar is narrowed down to a beam diameter of about 0.3 mm and irradiated onto the electrode axis XOH image for about 0.5 seconds, this end face is shown as the solid line in Figure 8 (the line has a ridge and is shaped like 11). is melted and the nip is removed.

If this method is carried out in an oxygen-free atmosphere such as an inert gas, other parts of the electrode will not be damaged, and since the beam is narrowed down to the electrode axis diameter, parts other than the end surface will be processed. Furthermore, since the irradiation time is short, it does not cause thermal distortion in areas other than the irradiation area, and can be processed at high speed, making it suitable for mass production.

Note that if the end of the electrode shaft connected to the molybdenum foil 6o is melted in the same way as shown in Figure 8, and the end of the discharge air barrier is melted as shown in Fig. "S"
It is possible to improve the luminous flux maintenance rate by preventing the blackening of the pulp caused by the scattering of light, and the cathode bright spot 4 is stabilized.

In the above embodiments, the case of a single-layer coil was explained, but in the case of a two-layer coil shown in the first report, there are additional coils with a predetermined pitch and a predetermined length on the outer surface of the densely wound portion 11 shown in FIG. A small electrode can be manufactured in the same manner as in the above embodiment by winding the densely wound portion of 11 and further forming a loosely wound portion on top of the loosely wound portion 11. is a tortoise that can be manufactured in the same manner as in the above embodiment by using a pre-boiled wire instead of the coil wire shown in FIG.

Furthermore, in addition to the tungsten wire as the core wire, it is also possible to use a tungsten wire input with thorium oxide (TkO) in four ways.

Furthermore, the present invention is not limited to small metal halide lamps, but can also be applied to various electrodes such as small high pressure sodium lamps and medium and small high pressure mercury lamps.

Invention 91 The loosely wound portions of the electrode are wound continuously and alternately, the electrode is cut to a predetermined length at the loosely wound portions, and then the electrode is cut to the predetermined length. ! I! It is a good idea to remove the loosely wound portion of the core wire and then thermally or chemically melt at least the end of the core wire facing the sealing portion. Therefore, according to this method, even if the electrode has a small axis diameter of 0.3 mm or less, the electrode can be manufactured without bending the electrode axis or deforming the electrode coil part. , and enables large-volume production in a short period of time. In addition, there are no variations in the dimensions, shapes, etc. of the electrode shaft or electrode coil portion, and the quality becomes constant. Furthermore, since the ends of the electrode shafts are finished, cracks can be prevented from occurring in the sealing portions, and finishing of the ends is also suitable for mass production.

[Brief explanation of drawings]

Figures 1-(6) to V) are diagrams showing the structure of the electrode, Figure 2 is a characteristic diagram showing the relationship between the diameter of the electrode shaft and the restriking voltage, and Figures 3 to 3 are diagrams showing the present invention. Figure 6 shows a step-by-step diagram of an example of the method, Figure 6 is a rounding diagram to explain the problems when incorporating it into a rung, Figure @7 is a diagram showing an example of deburring processing at the end, and Figure 8 is a diagram showing an example of deburring the end. FIG. 3 is a configuration diagram of a completed electrode. 1... Electrode axis, 2. ! z, 4--electrode coil section, 1
0...Core wire, 11...Densely wound part, 1j-...Loosely wound part, 10...Laser beam transmitter. Applicant's representative Patent attorney Takehiko Suzue Figure 1 (A) CB) (C) Figure 2 Electric side shaft @ ci (mm) Figure 3 Figure 4 Figure 6

Claims (1)

[Claims] A core wire made of a high melting point metal with a diameter of 0.3 mm or less is wound with a high melting point metal wire having a diameter smaller than this core wire diameter in a single layer or in several layers at a predetermined pitch and a predetermined number of turns. and a loosely wound part wound at a pitch 4 larger than this densely wound part are wound in succession alternately, and the loosely wound part is cut to a predetermined length, and the product K is cut to this predetermined length. An electrode for a small metal vapor discharge lamp characterized in that the loosely wound portion of the electrode is cut off, and then at least the end of the core wire, which becomes the sealing side end of the electrode, is subjected to thermal or chemical K11 melting treatment. manufacturing method.