JPH08236016A - Secondary electrode assembly and discharge lamp bulb for arc tube - Google Patents

Abstract

PURPOSE: To simplify manufacturing processes and prevent disconnection between a lead wire and a lead supporting wire. CONSTITUTION: A secondary electrode assembly 12 for an arc tube 21 is such that a Mo wire 13 as a lead and a Fe wire 14 as a lead supporting wire 23 are integrally jointed by previous abutment welding. A W electrode 16 is mounted at one end of the Mo wire via a Mo foil 15 and another Mo foil 17 is mounted at one end of the Fe wire.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a novel arc tube secondary electrode assembly and discharge lamp bulb. More specifically, it is an object of the present invention to provide a secondary electrode assembly and a discharge lamp bulb in a novel arc tube that can simplify the manufacturing process and prevent disconnection between the lead wire and the lead support wire. .

[0002]

2. Description of the Related Art The arc tube of a discharge lamp, for example, a metal halide lamp (discharge lamp) used as a light source of an automobile headlight, has a glass tube with mercury,
The metal halide is enclosed and the electrode part is attached.

Conventionally, such an arc tube a is shown in FIG.
It is manufactured as shown in FIGS.

Step 1: A glass part tube b (see FIG. 13) is molded while being heated to form a spherical part c having a substantially spherical shape in its substantially central part. As a result, the spherical portion c
A glass tube e is formed in which straight straight tube portions d 1 and d 2 extend to opposite sides from both ends of the glass tube (see FIG. 14).

Step 2: The primary electrode assembly f is inserted from one straight pipe portion d, the end portion of the straight pipe portion d on the spherical portion c side is pinch-sealed, and the pinch seal portion g formed thereby is 1 The next electrode assembly f is inserted (see FIG. 15).

The primary electrode assembly f is a molybdenum wire (Mo
Line) h, a tungsten electrode (W electrode) j is attached via a molybdenum foil (Mo foil) i, the Mo foil i is positioned at the pinch seal portion g, and the tip of the W electrode j Are located in the spherical portion c. Incidentally, M
o Pinch sealing of the foil i part is to make the foil absorb the difference between the low thermal expansion coefficient of glass such as quartz and the thermal expansion coefficient of Mo,
This is to maintain airtightness.

Step 3: The glass tube e is filled with an inert gas such as argon (Ar) gas. This is to prevent contamination of mercury and metal halide, which are then inserted into the glass tube e, and adsorption of moisture. Next, mercury and pelletized metal halide are charged into a glass tube e filled with Ar gas (see FIG. 16). The mercury and the metal halide are stored in an Ar gas atmosphere in advance so that they will not come into contact with the atmosphere and be contaminated.
Then, the mercury and the metal halide charged in the glass tube e are located in the spherical portion c.

Step 4: The secondary electrode assembly k is inserted into the end of the straight tube portion d of the glass tube e charged with mercury and metal halides on the side of the spherical portion c (see FIG. 17). The secondary electrode assembly k is previously housed in an Ar gas atmosphere in the same manner as mercury and metal halides, so that the secondary electrode assembly k is prevented from coming into contact with the atmosphere and being contaminated. Similar to the primary electrode assembly f, the secondary electrode assembly k has a tungsten electrode (W electrode) j ′ attached to one end of a molybdenum wire (Mo wire) h ′ via a molybdenum foil (Mo foil) i ′. And the above Mo line h '
Is formed in a corrugated shape having a width slightly larger than the inner diameter of the straight tube portion d, and the W electrode j ′ is positioned on the central axis of the glass tube e. In addition, since the corrugated portion of the Mo line h'of the secondary electrode assembly k is in contact with the inner surface of the straight pipe portion d, the secondary electrode assembly k is restrained from moving in the axial direction of the glass tube e, and temporarily. Positioning of the W electrode j ′ is performed at a predetermined position in the spherical portion c (position where the distance between the primary electrode assembly f and the W electrode j is a predetermined distance). Position it.

Step 5: The Ar gas in the glass tube e in which the introduction of the mercury and the metal halide and the insertion of the secondary electrode assembly k have been completed is exhausted, and the Xe gas is supplied to the glass tube e at a predetermined pressure (large). Fill below atmospheric pressure).

Step 6: Chip off the open end of the glass tube e (see FIG. 18). At this time, the secondary electrode assembly k
Make sure all parts of are located in a closed space.

Step 7: The spherical portion c of the glass tube e is cooled with liquid nitrogen to condense the Xe gas to be positioned inside the spherical portion c, and the Mo of the secondary electrode assembly k of the glass tube e is also placed.
The portion of the foil i'is pinch-sealed and the spherical portion c of the glass tube e is
Is a closed space (see FIG. 19). As a result, mercury, metal halide, and liquefied Xe are stored in the spherical portion c, and the W electrode j of the primary electrode assembly f is set.
And the W electrode j ′ of the secondary electrode assembly k are arranged to face each other with a predetermined gap. The pinch seal is designed to keep the spherical portion c cooled with liquid nitrogen to keep the Xe gas in the spherical portion c condensed.
As a result, Xe is enclosed in the spherical portion c while being condensed. Then, if the cooling of the spherical portion c is stopped, the condensed Xe in the spherical portion c is gasified as the temperature becomes room temperature.

Step 8: Shroud glass 1 is welded to the glass tube e so as to cover the spherical portion c (see FIG. 20).

Step 9: An unnecessary portion of the glass tube on the side of the secondary electrode assembly k and an unnecessary portion of the Mo line h'of the secondary electrode assembly k are cut to form an arc tube a (FIG. 21). reference).

In the arc tube a, the Mo wire h'of the secondary electrode assembly k is bent in a later step, and the tip end of the lead support o attached to the plug n of the discharge lamp bulb m and the above Mo wire are previously bent. The discharge lamp bulb m is formed by welding in a state where the tip end of h ′ intersects with the arc tube a supported by the plug n (see FIG. 22).

[0015]

With the secondary electrode assembly k in the above-mentioned conventional arc tube a, the arc tube a is manufactured when the discharge lamp bulb m is manufactured.
Since the lead wire h'of the secondary electrode assembly k and the lead support wire o are welded, there is a problem that the welding process becomes complicated.

That is, in the conventional secondary electrode assembly k, after attaching the arc tube a to the plug n of the discharge lamp bulb m, the lead wire Mo wire h'is bent and attached to the tip and the plug n. The leading end of the attached lead support wire o must be crossed and welding must be performed while maintaining this state, which complicates the welding process and takes time. Moreover, if the welding is poor, the arc tube a, the plug n, and the lead support wire o must all be wasted, resulting in poor yield.

Further, the welded portion thus constructed has a problem that the welding force is weak and the wire is easily broken.

Further, after manufacturing the arc tube a,
Although the discharge lamp bulb m is manufactured as described above, the expensive Mo wire is wasted because the Mo wire h ′ of the secondary electrode assembly k was cut and discarded at that time. There was also.

[0019]

In order to solve the above-mentioned problems, the secondary electrode assembly in the arc tube of the present invention is constructed by integrally butt welding the lead wire and the lead support wire of the secondary electrode assembly. It is joined.

Further, the discharge lamp bulb of the present invention uses the secondary electrode assembly in which the lead wire and the lead support wire are integrally joined by butt welding.

[0021]

Therefore, according to the secondary electrode assembly in the arc tube of the present invention, the secondary electrode assembly is manufactured, that is,
Since the lead wire and the lead support wire are butt-welded with a small amount of work, the welding process does not become complicated, and even if welding failure occurs, the lead wire and lead support wire are simply wasted. Therefore, the yield can be improved as compared with the conventional one.

Since the lead wire and the support wire are butt-welded together, the welding force is strong and the occurrence rate of wire breakage can be reduced.

Further, since the lead wire portion, which has been conventionally required only for positioning the secondary electrode assembly in the glass tube, can be used as the lead support wire, the portion to be discarded after manufacturing the arc tube is It is possible to eliminate the waste of material.

According to the discharge lamp bulb of the present invention,
Since the secondary electrode assembly in which the lead wire and the lead support wire are integrally joined by butt welding is used, the occurrence rate of wire breakage can be reduced.

[0025]

The details of the secondary electrode assembly and the discharge lamp bulb of the arc tube of the present invention will be described below with reference to an example of the illustrated embodiment.

The description will be given in the order of the manufacturing steps of the discharge lamp bulb. Further, the steps up to fixing the primary electrode assembly to the glass tube are the same as the steps 1 and 2 of the above-mentioned conventional example, and therefore will be briefly described.

The glass tube 1 is formed by molding the glass tube 2 while heating it to form the spherical portion 3 and the straight tube portions 4 and 4 (see FIGS. 1 and 2).

The primary electrode assembly 5 is a molybdenum wire (Mo
When a tungsten electrode (W electrode) 8 is connected to one end of a wire 6 via a molybdenum foil (Mo foil) 7 and the end of the straight tube portion 4 of the glass tube 1 on the spherical portion 3 side is pinch-sealed. Then, the Mo foil 7 of the primary electrode assembly 5 is sandwiched, and the primary electrode assembly 5 is inserted into the sealing portion 9 formed by this (see FIG. 3).

The glass tube 1 to which the primary electrode assembly 5 is fixed is filled and evacuated with Ar gas, charged with mercury 10 and metal halide 11, filled with Xe gas, and the like.

In the secondary electrode assembly 12, a molybdenum wire (Mo wire) 13 and an iron wire (Fe) wire 14 are previously integrated by butt welding, and a molybdenum foil (Mo foil) 15 is provided at one end of the Mo wire 13. Through the tungsten electrode (W
Electrode 16 is attached, and the above-mentioned iron wire (Fe wire) 14 is attached.
Another molybdenum foil (Mo foil) 17 is attached and formed at one end of the (see FIG. 4).

The diameter of the Fe wire 14 is larger than that of the Mo wire 13, and when joined by butt welding, the Mo wire 13
Is embedded in the end of the Fe wire 14 (see FIG. 5).
When the wire diameter of the Mo wire 13 is made smaller than that of the Fe wire 14 so that the end portion of the Mo wire 13 is embedded in the Fe wire 14 after welding, the welding force can be increased. The secondary electrode assembly of the arc tube is not limited to this,
The lead wire and the lead support wire may have the same diameter.
The lead wire may have a larger diameter than the lead support wire.

Further, the butt welding of the Fe wire 14 and the Mo wire 13 may be performed by aceput welding or flash welding.

Insertion of the secondary electrode assembly 12 into the glass tube 1 is performed by an electrode assembly supply device (not shown).
When the Mo foil 17 on the side of the e-wire 14 is gripped, the lower end of the Fe wire 14 (the end on the side of the weld with the Mo wire 13) faces the magnet 18 arranged outside the glass tube 1. The Fe wire 14 is attracted to the magnet 18 (see FIG. 6).

Next, the secondary electrode assembly 12 is ungripped by an electrode assembly supply device (not shown), and then the axial position of the Fe wire 14 is regulated by the attractive force of the magnet 18 and the Fe wire 14, and the magnet 18 is illustrated. The secondary electrode assembly 12 is moved downward by an elevating means, and is positioned at a predetermined position. The predetermined position is
W electrode 8 and secondary electrode assembly 12 of the primary electrode assembly 5
This is a position where the W electrode 16 of is opposed to the W electrode 16 with a predetermined gap (see FIG. 7).

The primary electrode assembly 5 is used for this positioning.
The position of the magnet 18 is finely adjusted while monitoring the distance between the W electrode 8 and the W electrode 16 of the secondary electrode assembly 12 by, for example, a tool scope or visual inspection.

Further, the mercury 10 in the above-mentioned glass tube 1
Input of metal halide 11 and secondary electrode assembly 1
2 is inserted in an Ar gas atmosphere so that the mercury 10, the metal halide 11 and the secondary electrode assembly 12 are not contaminated.

Next, the Ar gas in the glass tube 1 is exhausted,
The glass tube 1 is filled with Xe gas at a predetermined pressure (atmospheric pressure or less).

Then, the position of the straight tube portion 4 of the glass tube 1 near the upper end portion is heated and chipped off (see FIG. 8). The tip-off portion is the portion of the Mo foil 17 attached to the tip of the Fe wire 14, whereby the secondary electrode assembly 12 is fixed in the glass tube 1, and thereafter the magnet 1
The position regulation of the secondary electrode assembly 12 by 8 becomes unnecessary.

As a result, a semi-finished product 19 having one end sealed and the other end hermetically closed by chip-off is formed. Then, the spherical portion 3 is cooled with liquid nitrogen, and the end of the straight pipe portion 4 on the spherical portion 3 side is heated and pinch-sealed while keeping the internal Xe gas condensed (see FIG. 9). The pinch seal sandwiches the Mo foil 15 attached to the end of the Mo wire 13 of the secondary electrode assembly 12 on the W electrode 16 side, and the secondary electrode assembly 12 is inserted into the sealing portion 20 formed by this. It will be in a state of being.

After that, the extra portion of the glass tube 1, that is,
The part on the chip-off side of the sealing part 20 is cut, and the surplus part of the secondary electrode assembly 12, that is, the part of the Mo foil 17 at one end is cut, and the arc tube 21 passes through aging and the like. Completed (see FIG. 10).

In the arc tube 21, the Mo wire 13 and the relatively long Fe wire 14 butt-welded to the Mo wire 13 are exposed from the sealing portion 20 on the secondary electrode assembly 12 side (FIG. 10). The Fe wire 14 is used as a lead support wire 23 of the discharge lamp bulb 22.

That is, the Mo wire 13 exposed from the arc tube 21 is bent at a predetermined position (see FIG. 11),
The Fe wire 14 is made parallel to the axis of the arc tube 21, an insulating sleeve 24 is externally fitted to the Fe wire 14, and this is attached to the plug 25 of the discharge lamp bulb 22 (see FIG. 12).

In the above-mentioned secondary electrode assembly 12 of the arc tube 21, the lead support wire is the Fe wire 14
The magnet 1 is formed of the magnet 1 and is positioned in the glass tube 1 outside the Fe wire 14 and the glass tube 1.
Since the magnet 18 is moved by utilizing the attraction force with the secondary electrode assembly 12,
It is not necessary to form a part of the waveform into a waveform.

It should be noted that the Fe wire serving as the lead support wire is formed in a corrugated shape, and the corrugated portion is brought into contact with the inner wall surface of the glass tube to regulate the position of the secondary electrode assembly in the glass tube as in the conventional case. good. In such a case, the Mo foil on the upper end of the secondary electrode assembly is unnecessary. Then, after creating the arc tube, straighten the corrugated part, and then
The Fe wire may be used as the lead support wire by bending the o wire.

[0045]

As is apparent from what has been described above, the secondary electrode assembly of the arc tube of the present invention is sealed in the glass tube by sealing one end of the glass tube with the primary electrode assembly inserted therethrough. It is manufactured by charging mercury and a metal halide, inserting the secondary electrode assembly from the other end of the glass tube, and sealing the other end of the glass tube with the secondary electrode assembly inserted therethrough. A secondary electrode assembly in an arc tube, wherein the secondary electrode assembly has an electrode and a lead wire connected via a metal foil,
A lead support wire is integrally joined to the tip of the lead wire by butt welding.

Therefore, 2 in the arc tube of the present invention
According to the secondary electrode assembly, the secondary electrode assembly is manufactured, that is, the lead wire and the lead support wire are butt-welded in a state where the amount of processing is small. Even if it occurs, it is only necessary to waste the lead wire and the lead support wire.
The yield can be improved.

Since the lead wire and the support wire are butt-welded together, the welding force is strong and the occurrence rate of wire breakage can be reduced.

Further, since the lead wire portion which has conventionally been required only for positioning the secondary electrode assembly in the glass tube can be used as the lead support wire, there is a portion to be discarded after the arc tube is manufactured. It is possible to eliminate the waste of material.

The discharge lamp bulb of the present invention is characterized by using a secondary electrode assembly in which a lead wire and a lead support wire are integrally joined by butt welding.

Therefore, according to the discharge lamp bulb of the present invention, since the secondary electrode assembly in which the lead wire and the lead support wire are integrally joined by butt welding is used, the occurrence rate of disconnection can be reduced.

The specific items shown in the above embodiment are as follows.
Each of these is merely an example of the embodiment when carrying out the present invention, and the technical scope of the present invention should not be limitedly interpreted by these.

[Brief description of drawings]

1 shows an example of a manufacturing process of an arc tube of the present invention together with FIG. 2 to FIG. 10, which is a schematic view showing a glass base tube in a process until a glass tube to which the present invention is applied is made. is there.

[Fig. 2] A part of a glass tube is heated to form a spherical portion,
It is the schematic which shows the state made into the glass tube.

FIG. 3 is a schematic view showing a state in which a primary electrode assembly is fixed to a glass tube.

FIG. 4 shows a process up to supporting the secondary electrode assembly in the glass tube together with FIGS. 5 to 8, and is an enlarged view showing the secondary electrode assembly.

FIG. 5 is an enlarged sectional view showing a welded portion of the secondary electrode assembly.

FIG. 6 is an enlarged cross-sectional view showing a state where a secondary electrode assembly is inserted in a glass tube.

FIG. 7 is an enlarged cross-sectional view showing a state in which the secondary electrode assembly is positioned in the glass tube.

FIG. 8 is an enlarged cross-sectional view showing a state in which a glass tube having a secondary electrode assembly inserted therein is chipped off.

FIG. 9 is a magnified cross-sectional view showing a process from a glass tube having a secondary electrode assembly fixed to a discharge lamp bulb together with FIGS. 10 to 12, and showing a pinch-sealed state. .

FIG. 10 is an enlarged cross-sectional view showing an arc tube formed by cutting an extra glass tube.

FIG. 11 is an enlarged cross-sectional view showing a state where the Mo wire is bent.

FIG. 12 is an enlarged cross-sectional view showing a state in which a plug is attached to form a discharge lamp bulb.

FIG. 13 shows an example of a conventional method for manufacturing an arc tube together with FIGS. 14 to 22, and this figure is a schematic cross-sectional view showing a glass tube.

FIG. 14 is a schematic cross-sectional view showing a state where a glass tube is formed by heating a part of the glass tube to form a spherical portion.

FIG. 15 is a schematic cross-sectional view showing a state in which the primary electrode assembly is fixed to the glass tube.

FIG. 16 is a schematic cross-sectional view showing a state where mercury and a metal halide are charged.

FIG. 17 is a schematic cross-sectional view showing a state where the secondary electrode assembly is inserted.

FIG. 18 is a schematic cross-sectional view showing a state where the glass tube is chipped off.

FIG. 19 is a schematic cross-sectional view showing a state in which the glass tube is pinch-sealed.

FIG. 20 is a schematic cross-sectional view showing a state in which the shroud glass is welded to the outer periphery of the spherical portion of the glass tube.

FIG. 21 is an enlarged cross-sectional view showing a state where an excessive glass tube is cut to form an arc tube.

FIG. 22 is an enlarged cross-sectional view showing a state in which a plug is attached to form a discharge lamp bulb.

[Explanation of symbols]

 1 Glass Tube 5 Primary Electrode Assy 10 Mercury 11 Metal Halide 12 Secondary Electrode Assy 13 Molybdenum Wire (Mo Wire) (Lead Wire) 14 Iron Wire (Fe Wire) 15 Molybdenum Foil (Mo Foil) 16 Metal Tungsten Electrode (W electrode) (electrode) 21 arc tube 22 discharge lamp bulb 23 lead support wire

Claims (4)

[Claims] 1. A glass tube is sealed at one end thereof with a primary electrode assembly inserted therein, and mercury and a metal halide are introduced into the glass tube, and then a secondary electrode assembly is inserted from the other end of the glass tube. A secondary electrode assembly in an arc tube manufactured by inserting the glass tube and sealing the other end of the glass tube with the secondary electrode assembly inserted therethrough, the secondary electrode assembly including a metal foil. A secondary electrode assembly in an arc tube, wherein an electrode and a lead wire are connected together, and a lead support wire is integrally joined to the tip of the lead wire by butt welding. 2. The secondary electrode assembly for an arc tube according to claim 1, wherein the lead wire is a molybdenum wire and the lead support wire is an iron wire. 3. The lead support wire is thicker than the lead wire, and the lead wire is embedded in the end portion of the support wire at the welded portion. Secondary electrode assembly in the arc tube of. 4. A discharge lamp bulb using the secondary electrode assembly in the arc tube according to claim 1, claim 2, or claim 3.