KR20200115094A - Discharge lamp and method for producing the discharge lamp - Google Patents

Abstract

Provided is a discharge lamp with a sealing structure with excellent thermal durability. In a sealing tube (20) of the discharge lamp (10), an electrode support rod (22A) is inserted, and an inner metal ring (26) to which a metal foil (36) connected from an outer peripheral surface is inserted into a mount component (18A). The inner metal ring (26) is formed in a bowl shape with a disk unit (26B) and an extension unit (26C) extending from the periphery thereof to be gradually widen.

Description

Discharge lamp and its manufacturing method {DISCHARGE LAMP AND METHOD FOR PRODUCING THE DISCHARGE LAMP}

The present invention relates to a discharge lamp, and more particularly, to a sealing structure of a sealing tube in which an electrode mount component is disposed.

In a large-sized short arc type discharge lamp (for example, 1 kW or more), in order to improve the production efficiency of semiconductor and liquid crystal manufacturing, high power has been increased. Since the electrode increases in size with the increase in power consumption, the sealing tube in which the mounting parts are disposed is also enlarged accordingly.

In such a mount component of a discharge lamp, a metal ring is fixed to an electrode supporting rod held by a cylindrical glass tube, and a plurality of strip-shaped metal foils are welded to the outer peripheral surface of the metal ring.

Thereby, electric power is supplied to the electrode in the light emitting tube through the metal foil, the metal ring, and the electrode support rod.

During lamp lighting, cracks tend to occur in the sealing tube in the vicinity of the metal ring or the strip-shaped metal foil due to the difference in the amount of thermal expansion between the metal parts and the sealing tube. In order to prevent this, for example, the thickness of the strip-shaped metal foil is determined to be a unique thickness so as to satisfy a predetermined conditional expression (see Patent Document 1).

Japanese Patent Registration No. 6371275

In order to increase the size of the exposed object or improve the throughput, a higher output of the discharge lamp is required, and in order to realize precise exposure, the current flowing when the lamp is lit becomes a high current. get affected. In such a discharge lamp, it is difficult to suppress the occurrence of cracks only by adjusting the thickness of the metal foil.

Therefore, in a discharge lamp, it may be required to provide a sealing structure of a sealing tube excellent in thermal durability.

The discharge lamp of the present invention supports an electrode in a light-emitting tube, an electrode support rod disposed in a sealing tube integrally connected to the light-emitting tube, a glass tube through which the electrode support bar is inserted and welded to the sealing tube, and disposed along the electrode axis. And a metal member electrically connecting the formed metal foil and the electrode supporting rod. For example, the sealing tube can be constituted by a plurality of sealing tubes such as double sealing tubes.

Further, the metal member includes a disk portion and an extension portion extending from at least a portion of a circumference of the disk portion toward the light-emitting tube, and the extension portion extends in a direction away from the electrode support rod with respect to the electrode shaft. Here, it is sufficient if at least a part of the extension part extends in a direction away from the electrode axis, and the direction extending from the periphery of the disk may be formed in a direction inclined with respect to the electrode axis. It is also possible to configure it so as to be inclined at the end extended by the 直狀).

The entire extension part may extend in the same direction, or may be extended by changing an angle from the end side. For example, the extension portion may be configured to form a conical surface, and a conical surface and a circumferential surface may be formed, and an end side may be provided with a straight-top portion extending parallel to the electrode axis. It is preferable that the extension part be inclined in a range of 0°<θ≦15° with respect to the electrode axis.

The end of the extension part can be configured to face the glass tube so as not to affect the sealing tube by thermal expansion. For example, a stepped portion may be provided at an end portion of the glass tube opposite to the metal member so that the end portion of the extension portion faces the stepped portion. It is preferable to form a gap for accepting the thermal expansion of the extended portion at least in part (especially on the side of the end face of the extended portion facing the glass tube) around the extended portion.

When a metal foil and a foil member covering the metal member are provided, in order to cover the extension with the foil member, it is preferable that the end of the foil member on the glass tube side is positioned on the glass tube side than the end of the extension. It is also possible to install a disc foil disposed between the glass tube and the metal member and having a shape corresponding to the metal member.

A discharge lamp of another shape of the present invention includes an electrode support rod disposed in a sealing tube integrally connected to the light emitting tube and supporting an electrode in the light emitting tube, a glass tube through which the electrode support rod is inserted and welded to the sealing tube, and an electrode A metal member electrically connecting the metal foil disposed along the axis and the electrode support rod is provided, and the metal member includes a disk portion and an extension portion extending from at least a part of a circumference of the disk portion toward the light emitting tube, and the extension portion is along the electrode axis. It extends, and its end faces the glass tube.

In the metal member of another aspect of the present invention, in the metal member encapsulated in the sealing tube of the discharge lamp and disposed coaxially with the electrode support rod installed in the sealing tube, at least from the periphery of the disk portion to form a disk portion and a conical surface. It has an extension part provided with an inclined part extending so that it gradually widens in the lateral direction of one disk part.

Another method of manufacturing a discharge lamp according to the present invention includes a process of processing a disc-shaped metal material to form a shape including a conical surface that becomes braille widening from its periphery, and forming a bowl-shaped metal member; , A step of welding the electrode support rod to a metal member, and a step of inserting and sealing a mount component including the metal member into the sealing tube.

According to the present invention, it is possible to provide a discharge lamp having a sealing structure excellent in thermal durability.

1 is a schematic configuration diagram of a short arc type discharge lamp according to the present embodiment.
Fig. 2 is a cross-sectional view of the sealing tube on the cathode side.
Fig. 3 is a schematic cross-sectional view of a sealing tube in the vicinity of a metal member.
4 is a cross-sectional view of a metal member.
Fig. 5 is a diagram showing a metal member that is a modified example of the present embodiment.
[Fig. 6] Fig. 6 is a diagram showing a metal member that is a second modified example of the present embodiment.
Fig. 7 is a diagram showing a graph showing the degree of reduction of stress for a sealing tube.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

1 is a schematic cross-sectional view of a short arc type discharge lamp according to the present embodiment.

The short arc type discharge lamp 10 is a discharge lamp in which an anode 14 and a cathode 16 are disposed opposite to each other in a light-emitting tube 12 made of quartz glass, and quartz glass is encapsulated at both ends of the light-emitting tube 12. The tubes 20 and 60 are integrally formed to face each other.

A component (hereinafter referred to as a mount component) that supports the cathode 16 and the anode 14 inside the sealing tubes 20 and 60 and seals the discharge space 11 in the light emitting tube 12 18A, 18B) are sealed, respectively, and both ends of the sealing pipes 20 and 60 are closed with clasps 80A and 80B. Mercury and a rare gas are enclosed in the discharge space 11, and the amount of mercury is determined so as to emit light with a rated power of 1 kW or more, for example.

FIG. 2 is a schematic cross-sectional view of the vicinity of the mount part 18A on the cathode side of FIG. 1. Here, the clasp 80A is omitted. In addition, the mounting part 18B on the anode side has the same configuration.

The sealing tube 20 has a double tube sealing structure here, and is composed of an inner sealing tube 20A and an outside sealing tube 20B, and the inner sealing tube 20A and the outer sealing tube 20B are welded together. have. The mount part 18A is a cylindrical thick glass tube (hereinafter referred to as a glass tube) 24, a columnar glass member 34, and a plurality of It is provided with a strip-shaped metal foil (36). The inner sealing tube 20A is welded to the glass tube 24 and the glass member 34.

In the sealing tube 20, an electrically conductive electrode support rod 22A supporting the cathode 16 is disposed along the electrode axis E (lamp axis). The electrode supporting rod 22A is inserted into a shaft hole 24A formed in the glass tube 24 and held by the glass tube 24.

On the other hand, on the sealing tube end side (the clasp 80A side), the electrically conductive lead rod 28 is arrange|positioned so that the electrode support rod 22A may be opposed. The electrode support rod 22A and the lead rod 28 are shaft-inserted into holes (concave portions) 34A and 34B provided at both ends of the glass member 34, respectively, and the glass member 34 Holds the electrode support rod 22A and the lead rod 28. The lead rod 28 is connected to an external lead wire (not shown) connected to a power supply unit (not shown).

At both ends of the glass member 34, metal rings (metal members) 26 and 32 are disposed, respectively, and the electrode support rod 22A and the lead rod 28 are respectively provided with shaft holes ( It is welded to 26A and 32A, and is coaxially arranged with respect to the electrode shaft E together. The metal rings 26 and 32 can be made of any electrically conductive metal material (for example, tungsten, molybdenum, tantalum, etc.).

The metal ring (hereinafter referred to as the inner metal ring) 26 close to the light-emitting tube 12 is fitted in the disc-shaped disc foils 42 and 44 with holes for inserting the electrode support rods 22A. In addition, the other metal ring (hereinafter, referred to as an outer metal ring) 32 is similarly fitted to the disk-shaped disk foils 52 and 54. On the end side of the sealing tube, a thick fixed glass tube 50 for holding by inserting the lead rod 28 is fixed.

Between the inner metal ring 26 and the outer metal ring 32, a plurality of strip-shaped metal foils (for example, molybdenum foil) 36 extend along the outer surface of the glass member 34 along the electrode axis E. The both ends are welded to the outer peripheral surfaces of the inner metal ring 26 and the outer metal ring 32. The outer metal ring 32 electrically connects the lead rod 28 and the metal foil 36, and the inner metal ring 26 electrically connects the metal foil 36 and the electrode supporting rod 22A.

3 is a schematic cross-sectional view of the sealing tube 20 in the vicinity of the inner metal ring 26. 4 is a cross-sectional view of the inner metal ring 26.

The inner metal ring 26 has a disk portion 26B having flat on both sides as a base portion, and a ring-shaped extension portion 26C extending from the periphery of the disk portion 26B toward the light emitting tube is formed. The extension part 26C forms a conical surface 26S3 that gradually widens toward the light-emitting tube side, and when viewed from the light-emitting tube side, the inner metal ring 26 has one side surface 26S2 as the bottom. It is formed in the shape of a bowl (bowl).

As shown in Fig. 4, the extension portion 26C is inclined with respect to the electrode shaft E by an angle θ toward the outside of the sealing tube in a direction away from the electrode supporting rod 22A. Here, the angle θ is set in the range of 0°<θ≦15°. As for the end portion 26D of the extension portion 26C, the end face 26S4 is parallel to the disk portion 26B.

The glass tube 24 has a shape in which a cylindrical small-diameter portion 24D1, a medium-diameter portion 24D2, and a large-diameter portion 24D3 each having different diameters D1, D2, and D3 are extended, and a small-diameter portion ( Stepped portions J1 and J2 are formed between the 24D1 and the middle diameter portion 24D2, and the middle diameter portion 24D2 and the large diameter portion 24D3, respectively.

The extension portion 26C of the inner metal ring 26 faces the middle diameter portion 24D2 at a position in which the end face 26S4 faces the step portion J1. Further, a gap KS of the distance B along the electrode axis E is provided between the end face 26S4 of the extension part 26C and the middle diameter part 24D2. The strip-shaped metal foil 36 extends to the extension portion 26C of the metal ring 26 and does not contact the stepped portion J1, that is, the glass tube 24.

The stepped portion J2 is welded to the inner sealing tube 20A, and is in contact with the winding foil (foil member) 39. The winding foil 39 is made of a foil made of Mo or Ta, and extends in the electrode axis direction over the stepped portion J2 of the glass tube 24 from the vicinity of the inner metal ring 26 of the glass member 34, The glass member 34, the inner metal ring 26, and the small-diameter portion 24D1 and the middle-diameter portion 24D2 of the glass tube 24 are covered. However, the winding foil 39 is not shown in FIGS. 1 and 2.

The disk foil 42 in contact with the light emission observation side 26S2 of the inner metal ring 26 is formed in the same bowl (bowl) shape as the inner metal ring 26, and a conical surface is formed by the gradually widening extension. As a result, it is in contact with both the disk portion 26B and the extension portion 26C of the inner metal member 26. Therefore, the inner metal ring 26 does not come into contact with the small diameter portion 24D1 of the glass tube 24.

By introducing such an inner metal ring 26, it is possible to suppress the occurrence of cracks in the sealing tube during lamp lighting as described below.

During lamp lighting, the inner metal ring 26 thermally expands, but not only the disk portion 26B, but also the extension portion 26C extending along the direction close to the electrode axis, in other words, thermally expands. By dispersing the direction of thermal expansion in the radial direction and the oblique direction in which the extension portion 26C extends, the radial stress received by the winding foil 39 and the sealing pipe 20 is reduced (the stress is not concentrated in one direction). , Cracking can be suppressed. In particular, when the inclination angle θ is set to 15° or less, stress can be effectively suppressed.

In addition, since the extension portion 26C extends toward the light-emitting tube side, the metal foil 36 also thermally expands (pulls) in the direction of thermal expansion of the extension portion 26C, preventing agglomeration or crease of the metal foil 36. I can.

On the other hand, since the gap KS is formed between the end portion 26D of the extension portion 26C and the glass tube 24, the glass tube 24 or the sealing tube 20 when the extension portion 26C is thermally expanded. It is possible to suppress the occurrence of cracks without applying stress to Since this gap KS is determined by the distance between the small diameter portion 24D1 of the glass tube 24 and the end face 26S4 of the extension portion 26C, the length of the small diameter portion 24D1 in the electrode axis direction is adjusted. That is, by determining the shape of the stepped portion J1, the gap KS can be set to a desired length in the electrode axis direction. Further, since the end portion 26D of the extension portion 26C is arranged to face the glass tube 24, it is possible to perform the sealing operation stably.

In addition, the winding foil 39 covering the glass member 34 extends beyond the end portion 26D of the extension portion 26C and extends until it contacts the glass tube 24, and the winding foil 39 closes the gap KS. It is covered and exposed with a gap (KS). Accordingly, when the extension portion 26C thermally expands while the lamp is lit, the stress can be absorbed even by the deformation of the winding foil 39, so that the occurrence of cracks can be further suppressed.

The disk foil 42 arranged between the inner metal ring 26 and the glass tube 24 is formed in a bowl shape (a bowl shape) corresponding to the shape of the inner metal ring 26. Thereby, the occurrence of cracks in the glass tube 24 can be suppressed without the extension part 26C directly contacting the glass tube 24.

A discharge lamp having such a sealing structure can be manufactured according to the following manufacturing method. That is, the hole for the insertion of the electrode support rod is formed of a disc-shaped metal material, and the metal material is processed by press processing or the like to form a conical surface gradually widening from the periphery of the metal material, and a bowl-shaped (bowl-shaped) metal Mold the member. Then, while the electrode support rod is inserted into the metal member and welded, a strip-shaped metal foil is welded to the outer peripheral surface of the metal member to assemble the mount component. After inserting the mount component into the sealing tube, the sealing tube is reduced by heat, and the mount component is sealed. Thereby, a discharge lamp is manufactured. In addition, the assembly procedure of the discharge lamp is not limited to the above, for example, a hole for inserting an electrode support rod may be formed after pressing a metal material, or a metal material may be formed into a bowl shape after the electrode support rod is inserted. In addition to the press working, a member corresponding to the extension may be welded or a substantially bowl-shaped metal material may be cut and formed.

In the discharge lamp 10 of the present embodiment, a stepped portion is formed in the glass tube, but a glass tube without a stepped portion may be configured. In addition, the winding foil may be covered like a cap, or a configuration in which the winding foil is not provided. In the present embodiment, a double sealing tube is employed for a large discharge lamp, but it is also possible to have a sealing tube structure using a single tube other than the double sealing tube. Moreover, it is good also as a structure in which the original plate foil is not provided on the inner side of the metal ring.

Regarding the inner metal ring 26, the length of the extension portion along the electrode axis direction is arbitrary, but it may be set to be shorter than the diameter of the disk portion and longer than the thickness of the inner metal ring 26. In addition, rounds may be provided in each R (FIG. 4) of the disk portion 26B, and a radius of curvature of 0.3 to 5 may be determined.

The extension portion 26C extends from the entire periphery of the disk portion 26B to form a conical surface, but may be configured to extend from a portion of the periphery (for example, at predetermined intervals). Further, in the inner metal ring 26, only one electrode-side sealing tube may be applied, and the outer metal ring connected to the lead rod may also have the same configuration.

In the shape of the inner metal ring, in addition to the extension portion forming the conical surface, an extension portion further extending in the axial direction may be provided to form a circumferential surface.

5 is a diagram showing an inner metal ring in a first modified example of the present embodiment.

The inner metal ring 260 has a shape in which the extension part 260C extends from the periphery of the disk part 260B provided with the hole 260A to the light emitting tube side, and the extension part 260C forms a conical surface. The inclined portion 260C1 is formed, and a straight upper portion 260C2 extending along the electrode axis E to form a circumferential surface.

By providing the straight upper part 260C2 on the end side of the extension part 260C, the inside of the gap KS is expanded toward the stepped part J1 even when thermally expanded, thereby bringing about new crack suppression. Moreover, by providing the direct upper part 260C2, it becomes easy to weld with the metal foil 36. In addition, it is also possible to configure the extension part 260C only with the direct upper part 260C2, and you may comprise the inclined part 260C1 on the end side of the extension part 260C.

The shape of the inner metal ring is not limited to a bowl shape extending gradually from one side surface to the light emitting tube side, and an extension portion extending to the opposite side may be provided.

6 is a diagram showing an inner metal ring in a second modified example of the present embodiment. The inner metal ring 360 includes a disk portion 360B provided with a hole 360A, and extension portions 360C1 and 360C2 extending in both directions gradually widening from the periphery of the disk portion 360B. Is being formed. Thereby, thermal expansion is performed in the oblique direction of the extension parts 360C1 and 360C2, and the same effect as the inner metal ring 26 can be obtained.

[Example]

The discharge lamp of this embodiment is modeled on a computer by a discharge lamp corresponding to the embodiment, and reproduces a structure equivalent to a glass tube with a stepped portion, a winding foil, and a double sealed tube. Hereinafter, lighting simulation was performed under predetermined lighting conditions while changing the inclination angle of the extension part, and the degree of reduction of the stress on the sealing tube was investigated. However, simulation was conducted under the condition of stably lighting by supplying 8kW of power.

7 is a diagram showing a graph showing the relationship between the inclination angle of the extension and the degree of reduction of the stress on the sealing pipe. In the comparative example, a discharge lamp constituted of a conventional disk-shaped inner metal ring without an extension is modeled. Configurations other than the inner metal ring are the same as those of the embodiment. The vertical axis represents the ratio of the stress value when the stress value of this comparative example is set to 1 and the inclination angle of the example is changed. The possibility of breakage of the sealing tube is low by the low value.

As is clear from Fig. 7, the value decreases as the inclination angle θ increases. It decreases most at 10°, and thereafter, the value does not decrease. That is, it can be seen that stress can be effectively suppressed, particularly by setting the inclination angle θ to 15° or less. Moreover, since the value is also lowering even at an inclination angle of 0°, it has been found that there is an effect even if an extension portion is formed only in the straight upper portion shown in the first modification.

10 discharge lamp
20 Bongji Hall
22A electrode support rod
24 glass tube
26 Inner metal ring (metal member)
26B disc
26C extension

Claims (13)

An electrode support rod that supports an electrode in the light-emitting tube and is disposed in a sealing tube integrally connected with the light-emitting tube,
A glass tube through which the electrode support rod is inserted and welded to the sealing tube,
A metal member electrically connecting the metal foil disposed along the electrode axis and the electrode support rod,
The metal member includes a disk portion and an extension portion extending from at least a portion of a circumference of the disk portion toward the light emitting tube,
The discharge lamp, wherein the extension part extends in a direction away from the electrode support rod with respect to the electrode axis.
The method of claim 1,
The discharge lamp, characterized in that the extended portion forms a conical surface.
The method according to claim 1 or 2,
The discharge lamp, characterized in that the extended portion forms a conical surface and a circumferential surface.
The method according to claim 1 or 2,
The discharge lamp, characterized in that the extension is inclined in a range of 0°<θ≦15° with respect to the electrode axis.
The method according to claim 1 or 2,
A discharge lamp, wherein an end of the extension portion faces the glass tube.
The method according to claim 1 or 2,
A discharge lamp, wherein a gap is formed in at least a part of the periphery of the extension part.
The method according to claim 1 or 2,
The glass tube has a stepped portion at an end opposite to the metal member,
Discharge lamps, characterized in that the end portions of the extension face each other with the stepped portion.
The method according to claim 1 or 2,
Further comprising a foil member covering the metal foil and the metal member,
The discharge lamp, characterized in that the end of the foil member on the glass tube side is located on the glass tube side than the end of the extension part.
The method according to claim 1 or 2,
Discharge lamp, characterized in that it further comprises a disk foil disposed between the glass tube and the metal member and having a shape corresponding to the metal member.
The method according to claim 1 or 2,
The discharge lamp, characterized in that the sealing tube is composed of a plurality of sealing tubes.
In the metal member encapsulated in the sealing tube of the discharge lamp and disposed coaxially with the electrode support rod installed in the sealing tube,
With the disc,
An extension portion provided with an inclined portion extending gradually from the periphery of the disk portion in a lateral direction of at least one disk portion to form a conical surface,
A metal member comprising a.
An electrode support rod that supports an electrode in the light-emitting tube and is disposed in a sealing tube integrally connected with the light-emitting tube,
A glass tube through which the electrode support rod is inserted and welded to the sealing tube,
A metal member electrically connecting the metal foil disposed along the electrode axis and the electrode support rod,
The metal member includes a disk portion and an extension portion extending from at least a portion of a circumference of the disk portion toward the light emitting tube,
The discharge lamp, characterized in that the extension part extends from the periphery along the electrode axis, and the end thereof faces the glass tube.
A process of processing a disk-shaped metal material to form a shape including a conical surface to gradually widen from its periphery, and forming a bowl-shaped metal member;
A step of welding an electrode support rod to the metal member,
Inserting and sealing the mount component including the metal member into the sealing tube,
Method of manufacturing a discharge lamp comprising a.

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