JPH10302716A - Metallic vapor discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic vapor discharge lamp without causing dispersion in an electrode mount length during emitting tube manufacturing and also without causing shift of the center of electrode core, electrode supporting tube, or caulking position, allowing the improvement of work, stabilizing of quality without fluctuation of lamp voltage while a lamp is on, being excellent in lamp characteristics, for a discharge lamp using an electrode mount comprising of sintered electrodes and an electrode supporting tube. SOLUTION: This discharge lamp seals electrode mount at both ends of translucent aluminum tube 1, seals an emitting material inside the tube. The electrode mount shall be composed of an electrode supporting tube 3 sealed at both ends of emitting tube and a sintered electrode 4 fixed at a top edge of the supporting tube 3. In this case, the sintered electrode 4 is composed of a core bar and a main body, the core bar and the main body being unitedly formed of a sintered body.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an improvement in an electrode used for an arc tube for a metal vapor discharge lamp, and more particularly to an improvement in a mounting structure between an electrode support tube and a sintered electrode.

[0002]

2. Description of the Related Art In an electrode mounting structure for a metal vapor discharge lamp using a sintered electrode, when an electrode body and an electrode support tube are welded, an electrode core rod integrated with the electrode body is fixed by a certain length. After being inserted into the opening of the support tube, the opening is caulked, and then plasma welding is performed to fix the opening. FIG. 6 is an explanatory view showing a main part of the electrode mounting structure. In the figure, reference numeral 31 denotes an electrode support tube, and a sintered electrode body 32 and an electrode core bar 33 are fixed to the opening at the tip thereof by caulking. Have been.

Further, in an electrode mounting structure in which the coldest part of the arc tube of a metal vapor discharge lamp using a sintered type electrode is in an electrode support tube, when the lamp is turned on, sodium-ion in the arc tube is turned on.
An insertion hole is formed in an electrode support tube for the distribution of mercury amalgam vapor.

[0004]

In such a structure,
When caulking the electrode core rod and the electrode support tube, the distance between the electrode body and the electrode support tube is shifted, the overall length of the electrode mount fluctuates, adversely affects the lamp voltage, the center of the electrode core bar, the center of the electrode support tube or When the center of the swaging position is shifted and the electrode main body is tilted, there is a problem that the arc length between the two electrodes varies and affects the lamp voltage.

Further, in a structure in which an insertion hole is formed in the electrode support tube for the distribution of amalgam vapor, when an electrode mount is manufactured, it is necessary to form an insertion hole in the electrode support tube. There is a problem that the electrode support tube is dented, burred, and that the electrode support tube must be cleaned after the hole is formed. Further, the position of the hole formed in the electrode support tube is shifted and overlaps with the electrode core rod portion, or overlaps with the disk at the end of the arc tube, thereby closing the amalgam vapor insertion hole or sealing the arc tube. In this case, a problem occurs in that the frit blocks the inflow hole.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and is directed to a discharge lamp using a sintered electrode and an electrode support tube as an electrode mount of an arc tube for a metal vapor discharge lamp. Not only is there a variation in the overall length, but also the center of the electrode rod, the center of the electrode support tube, or the center of the caulking position does not shift, improving workability and stabilizing the quality. An object of the present invention is to provide a metal vapor discharge lamp having no fluctuation and excellent lamp characteristics.

Further, the present invention eliminates the operation of forming a through hole in the electrode support tube during the manufacturing process in an electrode mount structure of an arc tube having a coldest portion in the electrode support tube using a sintered electrode. An object of the present invention is to provide a metal vapor discharge lamp with good workability and stable quality without blocking the amalgam distribution port during mount production.

[0008]

In order to achieve the above-mentioned object, the present invention comprises an electrode mount sealed at both ends of a light-transmitting alumina tube and a light-emitting substance sealed in the tube. An electrode support tube sealed at both ends of the tube and a sintered electrode fixed to the tip of the support tube, the sintered electrode comprising a core rod portion and a main body portion, The part and the main body are formed integrally by a sintered body.

Further, the present invention provides an electrode support tube sealed at both ends of a light-transmitting alumina tube by sealing electrode mounts at both ends of the tube and enclosing a light-emitting substance in the tube. And a sintered electrode fixed to the tip of the support tube. The sintered electrode comprises a core rod and a main body, and the core rod and the main body are integrally formed by a sintered body. And an insertion hole or an insertion groove for amalgam distribution of the luminescent substance is formed in the sintered body.

[0010] The electrode is integrated by a sintered body, the diameter of the core rod and the inner diameter of the electrode support tube are made the same, and a projection is provided on the electrode body for locking the opening of the electrode support tube. This eliminates variations in the total length of the electrode mount and the arc length, and prevents variations in the lamp voltage.

Further, since the sintered electrode has an amalgam vapor flow port, the amalgam vapor flow port is not blocked during the production of the electrode mount, thereby preventing the arc tube from being defective and the electrode mount being produced. Improve the workability at the time.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. FIG. 1 is a cross-sectional view of a main part of an arc tube of a metal vapor discharge lamp according to the present invention, and FIG. 2 is a cross-sectional view of a main part of an electrode mount. In the figure, reference numeral 1 denotes a translucent alumina tube, and alumina disks 2 are sealed at both ends thereof, and an electrode mount comprising a niobium electrode support tube 3 and a sintered electrode 4 is provided at the center of the disk 2. Is sealed through, and an amalgam of sodium and mercury is sealed inside with an inert gas.

The sintered electrode 4 comprises an electrode body 5 and an electrode core 6 and is integrated by a sintered body of tungsten and an emitter. The core 6 is the same as the inner diameter of the electrode support tube 3. The main body 5 has at least one or more locking protrusions 7 for welding the sintered electrode 4 and the electrode support tube 3 at a predetermined position on the side surface of the main body 5. . In the figure, reference numeral 8 denotes an amalgam insertion hole formed in the electrode support tube 3, which is evacuated from the arc tube during production and sealed with amalgam or the like. In such a structure, when the sintered electrode 4 and the electrode support tube 3 are welded, variations in the arc length between the electrodes and variations in the lamp voltage due to variations in the entire length of the electrode mount can be prevented.

FIG. 3 is a sectional view of a main part of another electrode mount, in which a sintered electrode 4a is integrated with a sintered body composed of a main body 5a and a core rod 6a via a step 9, Core rod part 6
a is a columnar shape having the same diameter as the inner diameter of the electrode support tube 3, is inserted into the end of the electrode support tube 3, the end face of the support tube is brought into contact with the step 9, and welding is performed at a predetermined position. Fixed. In the figure, reference numeral 8 denotes an amalgam insertion hole.

FIGS. 4 (a) and 4 (b) are a sectional view and a plan view of a main part of an electrode mount according to a second embodiment of the present invention. The electrode 14 is inserted and fixed. The electrode 14 is integrated by a sintered body composed of a main body 15 and a core rod 16 via a step 19, and the core rod 16 is a column having the same diameter as the inner diameter of the electrode support tube 13, and An insertion hole 18 is formed as a through hole for amalgam vapor through the center of the sintered body. In such a structure, when manufacturing the electrode mount, not only the step of separately forming a through hole in the electrode support tube can be omitted, but also the failure of the arc tube due to blocking the flow port of the amalgam vapor can be prevented.

FIGS. 5A and 5B are a sectional view and a plan view of a main part of an electrode mount according to another embodiment, respectively.
It comprises an electrode support tube 23 and a sintered electrode 24. The sintered electrode 24 is integrated by a sintered body consisting of a main body 25 and a core rod 26 via a step 29, and the core rod 26 is It has a cylindrical shape having the same diameter as the inner diameter of the electrode support tube 23, and has a core rod portion 26.
A notch groove 28 for amalgam insertion is formed from the end face of the to the step portion 29.

[0017]

As described above, in the metal vapor discharge lamp according to the present invention, the inner diameter of the electrode support tube and the diameter of the electrode core rod are substantially the same, and the sintered electrode is connected to the locking projection or By locking and welding to the electrode support tube via the stepped portion, a change in lamp voltage due to variations in the arc length and variations in the entire length of the electrode mount can be prevented, and a lamp having stable characteristics can be obtained.

Further, another metal vapor discharge lamp according to the present invention is to improve the workability in the electrode mounting process and to close the amalgam vapor distribution port by forming the amalgam vapor distribution port in the sintered electrode. There is an advantage that a lamp in which the arc tube failure due to the above is prevented is obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an arc tube of a metal vapor discharge lamp according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part showing an arc tube electrode mount used in FIG.

FIG. 3 is a sectional view of a main part of another electrode mount.

FIGS. 4A and 4B are a main part cross-sectional view and a main part plan view showing a second arc tube electrode mount according to the present invention.

5A and 5B are a sectional view of a main part and a plan view of a main part of another electrode mount.

FIG. 6 is a sectional view of a main part showing a conventional arc tube electrode mount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Translucent alumina tube 2 Alumina disk 3,13,23 Electrode support tube 4,14,24 Sintered electrode 5,15,25 Electrode main body part 6,16,26 Electrode core rod part 7 Locking convex part 8 , 18 Insertion hole 28 Insertion groove 9, 19, 29 Step

Claims (4)

[Claims] 1. A metal vapor discharge lamp in which electrode mounts are sealed at both ends of a translucent alumina tube and a luminescent substance is sealed in the tube, wherein the electrode mounts are electrodes sealed at both ends of the arc tube. A support tube and a sintered electrode fixed to the tip of the support tube. The sintered electrode includes a core rod and a main body, and the core rod and the main body are sintered. A metal vapor discharge lamp characterized by being integrally formed by a body. 2. The core rod of the sintered electrode has a cylindrical shape having the same diameter as the inner diameter of the opening of the electrode support tube, and the main body locks the opening at a predetermined position. 2. The at least one locking projection of claim 1, wherein the core rod is inserted into the opening of the electrode support tube to a position where the projection abuts and is fixed. A metal vapor discharge lamp as described. 3. The main body of the sintered electrode has a cylindrical shape having a diameter larger than the inner diameter of the opening of the electrode support tube, and the main body and the core rod are integrally formed via a step. Forming
The metal vapor discharge lamp according to claim 1, wherein the step portion is configured to be a locking projection. 4. In a metal vapor discharge lamp in which electrode mounts are sealed at both ends of a translucent alumina tube and a luminescent substance is sealed in the tube, the electrode mounts are electrodes sealed at both ends of the arc tube. A support tube and a sintered electrode fixed to the tip of the support tube. The sintered electrode includes a core rod and a main body, and the core rod and the main body are formed of a sintered body. And a metal vapor discharge lamp formed integrally with the sintered body and having an insertion hole or an insertion groove for amalgam distribution of the luminescent substance in the sintered body.