JP2010262855A - High pressure discharge lamp and lighting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high pressure discharge lamp capable of reducing a deviation in a distance between electrodes in a back and forth direction of a melt-sealing of openings of a translucent ceramic discharging vessel, and to provide a lighting device. <P>SOLUTION: The high pressure discharge lamp includes: a translucent ceramic discharge vessel 21 which has an enclosure part 21a for enclosing a discharge space and of which the opening is formed on the enclosure part; a pair of electrode mounts 13a, 13b which are sealed in an opening with a pair of insertion parts 24 to be inserted toward the enclosure part from the opening of the discharging vessel, with the pair of the electrodes 22a, 22b, which are arranged with inner ends of the pair of the pair of insertion parts, respectively, and which are oppositely arranged with a predetermined inter-electrode distance L, and with a locking part 26, which is locked at the opening of the discharge vessel, and which is made of a high melting point metal for holding the predetermined inter-electrode distance; a discharging medium enclosed in the discharging vessel; and sealing parts 23a, 23b which seals a part including at least the locking part of the electrode mount by heat-melting the opening of the discharging vessel at a temperature capable of melting the locking part and seals the opening as well. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a high-pressure discharge lamp provided with a translucent ceramic discharge vessel, and an illumination device using the same.

  In a conventional high pressure discharge lamp equipped with a translucent ceramic discharge vessel, various modes have been proposed for sealing the discharge vessel through a current introduction conductor. Among them, the most widespread is an embodiment using a glass frit (see, for example, Patent Document 1).

  However, in this glass frit sealing, since the heat resistance of the glass frit is not sufficiently high, the temperature of the sealing portion must be suppressed to obtain the required lamp life characteristics. Therefore, since the tube wall temperature is lowered to reduce the tube wall load, the halide is not sufficiently evaporated and the vapor pressure cannot be increased. As a result, the luminous efficiency cannot be increased to the expected level. In addition, glass frit is relatively easy to react with a halogen compound of a luminescent metal, which is an example of an encapsulated discharge medium. Therefore, there is a problem that it is not possible to use a halide having good luminescence characteristics but high reactivity. .

  Therefore, a fritless sealing not using such a frit glass has been proposed and known. As an example of this fritless sealing, one end of a current introduction conductor is inserted into the opening end of a translucent ceramic discharge vessel, and the opening end of the translucent ceramic discharge vessel is heated and melted in the inserted state. Then, the current introduction conductor is sealed to the opening end and the opening end is sealed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 06-196131 JP 2007-115651 A

  However, in the fritless sealing as described in Patent Document 2, a straight rod-shaped current introduction conductor is allowed to have some play in the opening of the opening before heating and melting the opening of the ceramic discharge vessel. Since the opening is heated and melted in the inserted state, the insertion position may be displaced due to the current weight of the current introduction conductor during the heating and melting. For this reason, there exists a subject that the shift | offset | difference of the distance between electrodes of a pair of electrode arrange | positioned and arrange | positioned at the inner end of a pair of current introduction conductors, and an electrode axis center is large.

  The present invention has been made in view of such circumstances, and provides a high-pressure discharge lamp and an illuminating device that can reduce displacement between electrodes before and after fusion sealing of an opening of a translucent ceramic discharge vessel. It is in.

  A high-pressure discharge lamp according to claim 1 includes a surrounding portion that surrounds a discharge space, and a translucent ceramic discharge vessel having an opening formed in the surrounding portion; and inserted from the opening of the discharge vessel toward the surrounding portion. A pair of insertion portions, a pair of electrodes disposed at the inner ends of the pair of insertion portions and arranged to face each other with a predetermined distance between the electrodes, and the predetermined electrodes being locked to the opening of the discharge vessel A current-introducing conductor having a locking portion made of a refractory metal that holds a distance between the current introduction conductor and sealed in the opening; a discharge medium enclosed in the discharge vessel; and an opening in the discharge vessel, A sealing part that seals the opening and seals a part including at least the locking part of the current introduction conductor by heating at a temperature at which the locking part can be melted to melt. It is characterized by comprising;

  The present invention includes the following aspects.

[Translucent ceramic discharge vessel]
The translucent ceramic discharge vessel includes single crystal metal oxide such as sapphire and polycrystalline metal oxide such as translucent gas-tight aluminum oxide, yttrium-aluminum-garnet (YAG), yttrium oxide (YOX). And a non-crystalline polycrystalline oxide such as aluminum nitride (AlN), which is made of a ceramic material having optical transparency and heat resistance, and the internal discharge space is hermetically formed with respect to the outside. However, among the above materials, translucent polycrystalline alumina ceramics are suitable as a constituent material for translucent ceramic discharge vessels because they can be mass-produced industrially and are relatively easily available.

  The present inventor has newly established that the current introduction conductor can be sealed by heating the current introduction conductor and indirectly heating and melting the opening portion of the translucent ceramic discharge vessel by the heat transfer to weld the current introduction conductor to the current introduction conductor. I found it. The present invention has been made based on this new finding.

  The translucency in the translucent ceramic discharge vessel means that the light generated by the internal discharge can be transmitted to the outside and transmitted to the outside. It may be. Further, at least the main part of the part surrounding the discharge space only needs to have translucency, and if necessary, when it has an incidental structure other than the main part, the part may be light-shielding. .

  The translucent ceramics discharge vessel is provided with an enclosing portion in order to enclose the discharge space. The inside of the surrounding portion, that is, the discharge space is allowed to have an appropriate shape, for example, a spherical shape, an elliptical spherical shape, or a substantially cylindrical shape. Various values can be selected as the volume of the discharge space according to the rated lamp power of the high-pressure discharge lamp, the distance between the electrodes, and the like. For example, in the case of a liquid crystal projector lamp, it can be 0.5 cc or less. In the case of a vehicle headlamp, it can be 0.05 cc or less. Moreover, in the case of the lamp for general illumination, it can be set to either 1 cc or more and the following according to rated lamp electric power.

  Moreover, the translucent ceramics discharge container is provided with the opening part connected to an enclosure part. The opening functions to seal the translucent ceramic discharge vessel by inserting at least a current introducing conductor, which will be described later, into the opening, and sealing the current introducing conductor to the opening. Moreover, it can be made to function also in order to enclose the discharge medium mentioned later in the inside of a translucent ceramics discharge container, ie, an enclosure part.

  The number of openings is two for the configuration of sealing a general pair of electrodes, but it is allowed to be one to three or more depending on the number of current introduction conductors to be arranged. To do. When two openings are provided to seal a pair of electrodes, each opening is provided at a separate position, but preferably is concentrically spaced apart from each other along the tube axis. .

  The opening is separate when the translucent ceramic discharge vessel is formed, but after sealing together with the current introduction conductor, a cylindrical intermediate member integrated as an opening is additionally provided. Can be used. In other words, when the translucent ceramic discharge vessel is formed, the opening formed integrally with the current introduction conductor is directly fused to form a seal, and the translucent ceramic discharge is also formed. A cylindrical intermediate member made of ceramics or the like can be interposed between the opening integral with the container and the current introduction conductor. This intermediate member is allowed to be in a cylindrically solidified state or a powder state. The intermediate member is fused to the opening and the current introduction conductor to satisfactorily seal between them.

  Further, the opening may be formed continuously with the surrounding portion, and a small-diameter cylindrical portion continuing to the surrounding portion is incidentally formed, and an opening is formed at the end opposite to the surrounding portion of the small-diameter cylindrical portion. It may be. In the latter case, the length of the small diameter cylindrical portion is arbitrary. The ceramic in the opening may be light-shielding.

  The small-diameter cylindrical portion is a structure that has been adopted to form a so-called capillary structure that is conventionally used when sealing a translucent ceramic discharge vessel using frit glass. Thus, it is allowed to form a small diameter cylindrical portion so as to form a capillary structure. However, even when the capillary structure is not formed, the opening can be reliably sealed by forming the short cylindrical portion in the opening. In any of the above configurations, the size of the opening is determined by inserting the current introduction conductor and melting the translucent ceramic discharge vessel of the opening so that the molten translucent ceramic is introduced. It is formed in a size and a shape that can be welded to each other. The length of the sealing portion in the tube axis direction is allowed to be about 1 to 7 mm, preferably 1.5 to 4 mm.

In order to seal the translucent ceramic discharge vessel, the means for melting the ceramic in the opening is not particularly limited. For example, if the ceramic in the opening is heated to a temperature higher than its melting temperature and higher than the melting point of the refractory metal locking portion of the current-introducing conductor described later, the ceramic in the discharge vessel is melted and the opening The surface of the current introduction conductor inserted in the part can be wetted and made to conform. At this time, the engaging portion of the current introduction conductor is also melted and fused to the sealing portion of the opening. After that, if heating is stopped and the familiar part is cooled, the ceramic of the discharge vessel is cooled and solidified, the current introduction conductor is sealed in the opening, and the opening is sealed. The means for heating the ceramic in the opening is not particularly limited. For example, a heat ray projection type local heating means such as a laser or a halogen bulb with a reflector, an induction heating means, an electric heater, or the like can be used. As the laser, can be used, for example a YAG laser, CO ₂ laser and the like.

  When heating the entire circumference of the opening using the above-mentioned local heating means of the heat radiation type, the local heating means is fixed at a predetermined distance from the opening, for example, at the side of the opening, and the local heating means is operated. If either one or both of the opening of the translucent ceramic discharge vessel and the local heating means are rotated while being rotated, the entire circumference of the opening can be heated uniformly. However, if desired, a laser is irradiated from the extending direction of the opening, for example, the tube axis direction, a plurality of local heating means are arranged around the fixedly arranged opening, or the local heating means is opened to the opening. The translucent ceramic discharge vessel can be heated in a stationary state by rotating around the periphery of the tube or by providing a heating means that surrounds the entire circumference of the opening.

  Further, the current introduction conductor is heated by the laser or the like, and the opening portion of the ceramic discharge vessel that is in contact with the current introduction conductor and its engaging portion or in close proximity with the radiant heat of the heating is indirectly heated. And may be melted.

  In the case of manufacturing a translucent ceramic discharge vessel, the surrounding portion may be integrally formed, or may be formed by joining or fitting a plurality of components. Good. For example, when an incidental structure such as a small-diameter cylindrical portion is provided in addition to the surrounding portion, the incidental structure can be integrally formed from the beginning at both ends or one end of the surrounding portion. However, it is also possible to form an integral translucent ceramic discharge vessel by, for example, pre-sintering the surrounding portion and the incidental structure separately from each other and then joining them as required to sinter the whole. Alternatively, the cylindrical portion and the end plate portion can be pre-sintered separately and then joined together to sinter the whole, thereby forming an integrated surrounding portion.

[About the current introduction conductor]
The current introduction conductor is a conductor that functions to apply a voltage to an electrode to be described later, supply a current to the electrode, and seal the translucent ceramic discharge vessel. For this purpose, the inner end portion inserted into the opening of the translucent ceramic discharge vessel is connected to the electrode, and the outer end side is exposed to the outside of the translucent ceramic discharge vessel. The term “exposed to the outside of the translucent ceramic discharge vessel” means that it may or may not protrude from the translucent ceramic discharge vessel. You just have to face.

  Further, the current introduction conductor is a sealing metal, that is, niobium (Nb), which is a conductive metal whose thermal expansion coefficient is close to that of the translucent ceramic constituting the translucent ceramic discharge vessel, Metals such as tantalum (Ta), titanium (Ti), zirconium (Zr), hafnium (Hf), vanadium (V), platinum (Pt), molybdenum (Mo), and tungsten (W), and cermets can be used. . When aluminum oxide such as alumina ceramics is used as the material of the translucent ceramic discharge vessel, niobium and tantalum have the same average thermal expansion coefficient as aluminum oxide, and molybdenum has an average thermal expansion coefficient. Since it is close to that of the oxide, it is suitable for sealing. In the case of yttrium oxide and YAG, the difference is small. When aluminum nitride is used for the translucent ceramic discharge vessel, zirconium may be used for the current introduction conductor. Further, the current introduction conductor can be formed by joining a plurality of material portions. For example, a part of the metal selected from the above group may be used, and a cermet may be joined to the metal part in the tube axis direction or may be joined in the circumferential direction orthogonal to the tube axis. When a molybdenum (Mo) portion and a niobium (Nb) portion are provided on at least a part of the current introduction conductor, the opening of the translucent ceramic discharge vessel and the current introduction conductor are formed at the molybdenum and niobium portions. Sealing in between can be performed. For example, when the molybdenum part and the niobium part are heated by a laser or the like, the temperature of the molybdenum part and the niobium part rises, and this heat is transferred to the opening of the translucent ceramic discharge vessel, so that the part to be sealed becomes Melt and fuse to molybdenum den and niobium. Thereby, both a sealing part and a sealing part are formed.

  The engaging portion of the current introduction conductor is formed of a refractory metal such as Nb, Mo, or Ta. For example, it can be formed by fixing a thin wire made of a refractory metal perpendicular to the current introduction conductor body and fixing it by melting or the like. The length of the thin wire is formed to be a length that is locked to the outer end of the opening before melting, and is fused to the sealing portion after the sealing portion of the opening is formed.

[About electrodes]
The electrode is a means for causing discharge of a discharge medium, which will be described later, inside the translucent ceramic discharge vessel. In general, a pair of electrodes are disposed so as to be opposed to each other so that arc discharge occurs between the electrodes inside the translucent ceramic discharge vessel. In the present invention, at least one electrode is connected to the introduction conductor and sealed in the translucent ceramic discharge vessel.

  Further, the electrode is connected to the current introduction conductor, and is held at a predetermined position in the translucent ceramic discharge vessel by the engaging portion. For example, the base end of the electrode is connected to the inner end located on the inner side of the translucent ceramic discharge vessel of the current introduction conductor.

  Furthermore, as a material for the electrode, tungsten, doped tungsten, triated tungsten, rhenium, a tungsten-rhenium alloy, or the like can be used.

  Furthermore, when a pair of electrodes is used, they have a symmetrical structure in the case of an AC lighting type, but can be made an asymmetric structure in the case of a DC lighting type.

[Discharge medium]
The discharge medium is a means for obtaining desired light emission by the discharge, but the configuration is not particularly limited in the present invention. For example, the following modes are allowed. However, it is preferably composed of a luminescent metal halide, a lamp voltage forming medium and a rare gas. In the present invention, “high-pressure discharge” refers to a discharge in which the pressure during lighting of the ionized medium is equal to or higher than atmospheric pressure, and is a concept including so-called ultrahigh-pressure discharge.

  The luminescent metal halide is a luminescent metal halide that mainly emits visible light, and various known metal halides can be employed. That is, the metal halide of the luminescent metal obtains visible light radiation having desired luminescent characteristics with respect to luminescent color, average color rendering index Ra, luminescent efficiency, etc., and further, the size and input of the translucent ceramic discharge vessel Depending on the power, any desired metal halide can be selected as desired. For example, sodium (Na), scandium (Sc), rare earth metals (such as dysprosium (Dy), thulium (Tm), holmium (Ho), praseodymium (Pr), lanthanum (La) and cerium (Ce)), thallium (Tl) ), Indium (In) and lithium (Li), one or a plurality of halides selected from the group consisting of.

  The lamp voltage forming medium is an effective medium for forming a lamp voltage. For example, mercury or a metal halide described below can be used. That is, a halide as a lamp voltage forming medium is a metal such as aluminum, which has a relatively high vapor pressure during lighting and a small amount of light in the visible region compared to the amount of light emitted in the visible region. Halides such as (Al), iron (Fe), zinc (Zn), antimony (Sb), and manganese (Mn) are suitable. In the luminescent metal halide, one or more of iodine, bromine, chlorine and fluorine can be used as the halogen.

  The high-pressure discharge lamp according to claim 2 is characterized in that in the current introduction conductor, the locking portion is formed by a protrusion having a diameter larger than the inner diameter of the opening of the discharge vessel.

  The engaging portion of the current introduction conductor is formed to a size that can be engaged with the opening of the discharge vessel before melting, and the electrode formed at the inner end of the current introduction conductor by being engaged with the opening is predetermined. The position deviation of the electrode can be reduced even after the opening is melted.

  The high-pressure discharge lamp according to claim 3 is characterized in that the current introduction conductor is provided with a contact portion made of a refractory metal that comes into contact with an inner surface of a predetermined sealing portion of the opening.

  Since the contact portion is formed of a high melting point metal such as Nb, Mo, Ta, etc., like the locking portion, it is heated and melted together with the locking portion when the opening of the discharge vessel is heated and melted. You may form integrally with a stop part. Since the contact portion is in contact with the inner surface of the opening, the contact area between the opening and the current introduction conductor can be increased. For this reason, since the heat transfer area between the opening and the current introduction conductor can be increased, the heating of one of these can be quickly and efficiently transferred to the other. For this reason, the formation time of the sealing part of an opening part can be shortened. Further, since the contact portion of the current introduction conductor is in contact with the inner surface of the opening of the discharge vessel, a heat shock is generated at this portion, and a crack is easily generated at the opening. Furthermore, since this crack falls down and is welded to the current introduction conductor side, a sealing portion is easily formed.

  In addition, the contact portions can be easily aligned so that the central axes of the pair of current introduction conductors that are inserted into the openings and are opposed to each other coincide with each other. For this reason, the alignment of the pair of electrodes formed at the inner ends of the pair of current introduction conductors can be easily maintained, and the misalignment of the alignment after forming the sealing portion can be reduced.

  The illumination device according to claim 4 is an illumination device main body; a high-pressure discharge lamp according to any one of claims 1 to 3 disposed in the illumination device main body; a lighting circuit for lighting the high-pressure discharge lamp; It is characterized by comprising.

  According to the high pressure discharge lamp of the first aspect, when the sealing portion is formed by heating and melting the opening portion of the discharge vessel, the current introduction conductor inserted into the opening portion tends to be displaced by its own weight. However, since the current introduction conductor is locked to the opening by the locking portion, the displacement of the current introduction conductor, that is, the positional deviation is reduced.

  For this reason, it is also possible to reduce the deviation between a pair of electrodes formed and opposed to the inner ends of the pair of current introduction conductors.

  According to the high pressure discharge lamp of the second aspect, since the engaging portion of the current introduction conductor is larger in diameter than the inner diameter of the discharge vessel opening, simply placing the engaging portion on the outer end of the opening makes it easy. And it can be made to latch reliably.

  According to the high pressure discharge lamp of the third aspect, both the shortening of the formation time of the sealing portion by heating and melting of the opening portion by the contact portion of the current introduction conductor and the reduction of the misalignment between the axial centers of the pair of electrodes are achieved. Can do.

  According to the lighting device of the fourth aspect, since the high-pressure discharge lamp according to any one of the first to third aspects is provided, the lifetime as the lighting device can be extended.

The longitudinal cross-sectional view of the arc_tube | light_emitting_tube assembled | attached to the high pressure discharge lamp which concerns on the 1st Embodiment of this invention shown in FIG. The front view which shows the whole high pressure discharge lamp which comprised the arc tube shown in FIG. (A), (b), (c) is process drawing which each shows the formation process of the electrode mount shown in FIG. (A) is a sectional side view of the electrode mount shown in (c) of FIG. 3, (b) is a plan view of the electrode mount, and (c) is a plan view of an electrode mount of another modification. (A) shows the state which inserted the insertion part of the electrode mount shown in FIG.3 (c) in the opening part of a translucent ceramics discharge container, and mounted the latching protrusion on the outer end of the said opening part. The principal part longitudinal cross-sectional view, (b) is the principal part longitudinal cross-sectional view after forming the sealing part of the opening part. (A) is a longitudinal sectional view of the electrode mount according to the first modification of the present invention, (b) is inserted into the opening of the translucent ceramic discharge vessel the electrode mount insertion portion shown in (a), The principal part longitudinal cross-sectional view which shows the state which mounted the latching protrusion on the outer end of the said opening part, (c) is the principal part longitudinal cross-sectional view after forming the sealing part of the opening part. FIG. 7A is a process diagram illustrating an example of a manufacturing method of the electrode mount shown in FIG. 6A, wherein FIG. 6A is a process diagram before processing the electrode mount, and FIG. 6B is a second projection of the electrode mount. Process drawing which forms (contact part), (c) is process drawing which forms the 1st protrusion. FIG. 7A is a front view of the electrode mount shown in FIG. 6A, and FIG. 7B is a view showing a flat cross section of the first and second protrusions shown in FIG. (A) is a front view of an electrode mount shown in the second modified example of the present invention, (b) is an insertion portion of the electrode mount shown in (a) inserted into the opening of the translucent ceramic discharge vessel, The principal part longitudinal cross-sectional view which shows the state which mounted the latching protrusion on the outer end of the said opening part, (c) is the principal part longitudinal cross-sectional view after forming the sealing part of an opening part. The schematic side view of the illuminating device which concerns on the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected to the same or an equivalent part in several attached drawing.

  FIG. 1 is a longitudinal sectional view of an arc tube assembled to the high pressure discharge lamp according to the first embodiment of the present invention shown in FIG. 2, FIG. 2 is a front view showing the whole high pressure discharge lamp, and FIG. (C) is process drawing which shows an example of the manufacturing method of the electrode mount of the arc tube shown in FIG.

  As shown in FIG. 2, the high-pressure discharge lamp 1 has a structure suitable for a rated lamp power of 100 W and includes an arc tube 2. The arc tube 2 is enclosed in the outer tube 3.

  The outer tube 3 has a T-shaped bulb shape made of hard glass, and a flare stem 4 is sealed to the neck portion. The flare stem 4 introduces a pair of lead wires 4a and 4b in an airtight manner. The outer tube 3 accommodates and stores the arc tube 2 at a predetermined position inside it by support structures 5a and 5b described later.

  The UV enhancer 6 includes an airtight container, an introduction line, an internal electrode, a discharge medium, and an external electrode. The hermetic container is made of ultraviolet ray transmissive glass such as quartz glass, and a pinch seal portion is formed at one end thereof, thereby forming a long and narrow discharge space inside. The lead wire is welded to an internal electrode, which will be described later, led out to the outside from the pinch seal portion, and welded to one support frame 7a at the base end portion as shown in FIG.

  The internal electrode has a plate shape made of molybdenum, is sealed in a discharge space of an airtight container, and a base portion thereof is airtightly embedded in a pinch seal portion. The external electrode is made of a molybdenum wire having an outer diameter of 0.4 mm, and is closely wound on the outer periphery of the airtight container and is wound for five turns, and its base end is welded to the support structure 8b. Thus, the UV enhancer 6 is arranged at a predetermined position in the outer tube 3 by the base end portion of the lead-in line and the base end portion of the external electrode. With the structure described above, the UV enhancer 6 is connected in parallel with the arc tube 2 in the outer tube 3 and is held at a position close to one electrode of the arc tube 2.

  The shroud glass 9 is made of a cylindrical quartz glass body having an outer diameter of 1.0 mm and can be accommodated in the outer tube 3, and is held by a support member 45a described later at a position surrounding the arc tube 2 in the outer tube 3. Has been.

  One support structure 5 a includes support frames 7 a and 7 b, a bridge conductor 11, a pair of spring pieces 12 a and 12 b, and a support member 10. The lower ends of the support frames 7a and 7b are connected to one lead wire 4a in FIG. 1, and the upper ends are extended to form spring pieces 12a. The bridge conductor 11 supports the upper part of the arc tube 2 by being welded to an upper current introducing conductor (conductor) 13a in FIG. The pair of spring pieces 12 a and 12 b elastically contact the inner surface of the outer tube 3 to prevent the upper portions of the pair of support frames 7 a and 7 b from rolling with respect to the inner surface of the outer tube 3. The support member 10 a supports the upper and lower ends of the shroud glass 3.

  One support structure 5b is in the form of a straight bar, and the lower part thereof is electrically connected by welding to the lead-in wire 4b sealed to the flare stem 4, and is mechanically supported. . The upper end portion of the arc tube 2 is welded to a lower current introduction conductor (conductor) 13b in FIG. 2 via a connection conductor to support the lower portion of the arc tube 2.

  The base 14 is an E39-type base, and is fixed to the neck portion of the outer tube 3. One of a pair of lead wires (not shown) exposed to the outside from the outer tube 3 is connected to the shell portion and the other is connected to the center contact. ing. In FIG. 2, symbol G is a getter, which absorbs and purifies the impure gas in the outer tube 3, and is welded to the upper portion of the support frame 42a.

  As shown in FIG. 1, the arc tube 2 includes a discharge vessel 21, which is an example of a translucent ceramic discharge vessel, a pair of electrodes 22a, 22b, an electrode mount 13a, 13b which is an example of a pair of current introduction conductors, and a discharge. A discharge medium sealed inside the container 21 is provided.

  The discharge vessel 21 is mainly composed of alumina ceramics and contains a sintering aid, and has translucency. The discharge vessel 21 includes, for example, an oval enclosing portion 21a and a pair of small diameter cylindrical portions 21b and 21c disposed in communication with both ends of the enclosing portion 21a in the long diameter direction. The small diameter cylindrical portions 21b and 21c and the surrounding portion 21a are integrally formed by casting, and both ends in the axial direction of the pair of small diameter cylindrical portions 21b and 21c are opened as openings for inserting the pair of electrode mounts 13a and 13b. ing.

  For example, the encircling portion 21a is formed by connecting two hemispherical portions with a straight line in a state where two hemispherical spheres are axially spaced from each other so as to face each other, and has a substantially elliptical shape. The wall thickness is 0.8 mm.

  The pair of small-diameter cylindrical portions 21b and 21c each have a pipe shape with an inner diameter of about 1 mm, and the tip is integrally connected to the central portion of the corresponding hemispherical portion of the surrounding portion 21a. In addition, as for the boundary part of the surrounding part 21a and the small diameter cylinder parts 21b and 21c, the inner and outer both surfaces are formed by the curved surface.

  The electrodes 22a and 22b are each formed in an elongated straight rod shape made of a tungsten rod having a required length of 0.5 mm in outer diameter, and are concentrically integrated as inner ends of a pair of electrode mounts 13a and 13b having substantially the same diameter. It is connected.

  That is, as shown in FIGS. 3A to 3C, the electrode mounts 13a and 13b are directed from the electrodes 22a and 22b at the inner ends (lower ends in FIG. 3) to the outer ends (upper ends in FIG. 3). The molybdenum portion 13c formed in a straight rod shape with molybdenum Mo and the niobium portion 13e formed in a straight rod shape with the same diameter by the cermet 13d and niobium Nb are sequentially connected in a straight line in this order, and are integrally connected. The electrodes 22a and 22b are connected concentrically and integrally to the tip of each molybdenum (Mo) portion 13c by welding or the like, thereby forming the electrode shaft 13 shown in FIG. Cermet S is made of a mixture of alumina and molybdenum, and a volume ratio of 30 to 70% can be used, but 50% (50:50) is preferable.

  As shown in FIG. 3 (b), one refractory metal (for example, niobium Nb, molybdenum Mo, tantalum Ta) is formed on one side surface in the radial direction of the niobium portion 13e of the electrode shaft 13 as shown in FIG. The locking thin rod 26a is positioned in a cross shape so as to be orthogonal to each other, and fixed in a cross shape by welding as shown in FIGS. 3 (c), 4 (a), and 4 (b). Each of the locking thin rods 26a is formed to have an outer diameter of, for example, 30 to 100% with respect to the outer diameter of the electrode shaft 13, and is formed into a column or prism that is sufficiently longer than the inner diameter of the opening end of each of the small diameter cylindrical portions 21b and 21c. Two of the locking thin rods 26a may be fixed to each side surface in the radial direction at predetermined positions of the electrode shaft 13 by welding. Further, as shown in FIG. 4C, the electrode shaft 13 may omit the cermet 13d and extend the molybdenum portion 13c.

  The electrode mounts 13a and 13b formed in this way are inserted into the pair of small diameter cylindrical portions 21b and 21c from the distal ends on the electrodes 22a and 22b side, and are inserted concentrically from the outer ends of the openings, The base end portion on the niobium portion 13e side is hermetically protruding from the sealing portions 23a and 23b of the small diameter cylindrical portions 21b and 21c to the outside, and the electrode mounts 13a on the outer end sides of the sealing portions 23a and 23b. , 13b are provided with locking portions 26, 26 welded to the niobium portion 13e. A predetermined minute gap g is formed between the outer peripheral surface of each insertion portion 24 of the electrode mounts 13a and 13b and the inner peripheral surface of the small diameter cylindrical portions 21b and 21c. Each locking portion 26 is formed after heating and melting the locking rods 26a of the electrode mounts 13a and 13b, and the inner end portion of the locking portion 26 is integrally fused to the outer end portions of the sealing portions 23a and 23b. And the outer end part of the latching | locking part 26 is sealed by the outer end part of electrode mount 13a, 13b.

  The discharge medium is made of argon (Ar) as a starting gas and a buffer gas, the following metal halide, and mercury as a buffer vapor, and is enclosed in a translucent ceramic discharge vessel 21. Since metal halide and mercury are encapsulated in excess of the amount that evaporates, some of them stay in a liquid phase in a small gap formed in the small diameter cylindrical portions 21b and 21c during stable lighting. ing. In FIG. 2, the coldest part is formed in the vicinity of the surface layer portion of the discharge medium that stays in the liquid phase, for example, in the small-diameter cylindrical portion 13b that is on the lower side during lighting.

  The pair of sealing portions 23a and 23b are obtained by locally heating and melting the openings which are axially outer ends of the pair of small-diameter cylindrical portions 21b and 21c made of alumina ceramic, and cooling and solidifying after the heating. The opening is hermetically sealed with the insertion portions 24 of the electrode mounts 13a and 13b inserted therein.

  That is, as shown in FIG. 5A, first, the insertion portions 24, 24 of the pair of electrode mounts 13a, 13b are inserted into the open ends of the pair of small diameter cylindrical portions 21b, 21c, and the electrode 22a at the tip thereof. , 22b are inserted concentrically, and the locking thin rod 26a is locked to the open end outer surfaces of the small-diameter cylindrical portions 21b, 21c. As a result, the pair of electrodes 22a and 22b face each other concentrically within the surrounding portion 21a, so that the facing distance is set to a predetermined inter-electrode distance L and held by a required jig.

  Next, in this state, the outer surfaces of the predetermined sealing portions of the small-diameter cylindrical portions 21b and 21c are, for example, three directions with an angle that divides the circumferential direction into three equal parts, that is, 120 ° equal intervals (FIG. 5 ( a) A required laser beam such as a YAG laser having a wavelength of 1 μm is irradiated in a vertical direction with a required output from a direction indicated by a middle arrow). With a laser having a wavelength of 1 μm, it is possible to suppress the reflection of the laser beam by the electrode mounts 13a and 13b made of metal.

  Then, this laser beam passes through the opening end alumina of the small diameter cylindrical portions 21b, 21c, is absorbed by the metal niobium portion 13e of the electrode mounts 13a, 13b and the locking thin rod 26a, and is heated here. The locking rod 26a melts.

  Further, the open end portions of the small-diameter cylindrical portions 21b and 21c made of alumina ceramic are indirectly heated and melted by the radiant heat of the niobium portion 13e and the locking thin rod 26a. As a result, the melted alumina ceramic is fused and sealed to the niobium portion 13e of the electrode mounts 13a and 13b and its peripheral portion, and the openings of the small diameter cylindrical portions 21b and 21c are hermetically sealed.

  By the way, in order to avoid the occurrence of cracks C and large holes from the time when the small diameter cylindrical portions 21b and 21c are opened and melted from the locally melted state until the sealing portions 23a and 23b are formed. In addition, when the laser output when the small-diameter cylindrical portions 21b and 21c of alumina are locally melted is 100%, the power is gradually increased from the output at which the crack C due to thermal shock does not occur until the melted, When 100% output is reached, it is possible to control with less output by maintaining the 100% output for several seconds and then gradually decreasing the output to 0% within a certain time. Further, when the laser beam is irradiated, the focal point of the laser beam is shifted rearward from the outermost surface of the small-diameter cylindrical portions 21b and 21c facing the cermet portion 13d, for example, by 5 to 10 mm, thereby preventing heating from being concentrated on one point. It is possible to suppress the generation of cracks C accompanying rapid heating. As a result, breakage and leakage due to heat shock when the lamp is lit can be prevented or reduced.

  However, when a crack C occurs due to a heat shock during heating of the small-diameter cylindrical portions 21b and 21c, the opening end portion cracked by the crack C collapses toward the electrode mounts 13a and 13b, and the heat transfer area increases. Therefore, it becomes easy to melt | dissolve and the sealing parts 23a and 23b can be formed rapidly.

  Therefore, according to the arc tube 2, when the sealing portions 23a and 23b are formed by heating and melting the opening portions of the small-diameter cylindrical portions 21b and 21c of the discharge vessel 2, they are inserted into the opening portions. Although the electrode mounts 13a and 13b are also about to be displaced by their own weight, since the electrode mounts 13a and 13b are locked to the opening by the locking thin rods 26a, the displacement of the electrode mounts 13a and 13b, that is, Misalignment is reduced. The effect of reducing the displacement of the electrode mounts 13a and 13b is due to the fact that the displacement of the sealing portions 23a and 23b decreases due to the viscosity of the sealing portions 23a and 23b because the volume of the locking thin rod 26a is large.

  For this reason, the deviation of the interelectrode distance L between the pair of electrodes 22a and 22b formed and opposed to the inner ends of the pair of electrode mounts 13a and 13b can be reduced.

  FIG. 6A is a longitudinal sectional view of a pair of electrode mounts 13x and 13x according to a second modification of the present invention. The electrode mounts 13x and 13x are the same as the electrode mounts 13a and 13b shown in FIGS. 1, 3 (a) to 3 (c) and 4 (a) to 4 (c). The structure is the same as the pair of electrode mounts 13a and 13b except that the first protrusion 26b and the second protrusion 26c for stopping are replaced.

  That is, as shown in FIG. 6 (a), the electrode mount 13x is integrally formed with the first protrusion 26b as a locking portion at a middle portion in the axial direction of the niobium portion 13e of the electrode shaft 13 and slightly below it. The second protrusion 26c having a protrusion smaller than that of the first protrusion 26b is integrally formed as an example of the contact portion.

  The first protrusion 26b has a plurality of protrusions 26ba whose vertical cross section is substantially a right triangle so as to protrude outward from a plurality of equally divided positions (three directions) in the circumferential direction. As shown in FIG. 6B, the discharge vessel 21 is formed in a shape and size that is seated on the outer surface of the opening end of the small-diameter cylindrical portions 21 b and 21 c and is locked to the opening end.

  On the other hand, as shown in FIG. 6B, the second protrusion 26c protrudes outward from the circumferential direction of the niobium part 13e by a plurality of protrusions 26ca having a substantially vertical cross section, and the protruding tip is a small diameter tube. It forms so that each may contact the inner surface of the parts 21b and 21c.

  7A to 7C show an example of a processing method of the electrode mount 13x. The electrode mount 13x is substantially the same as the electrode shaft 13 of the electrode mounts 13a and 13b according to the first embodiment, and the electrodes 22a and 22b, the molybdenum portion 13c, the cermet 13d, and the niobium portion from the lower end to the upper end in the figure. 13e is sequentially formed in this order, and only the niobium portion 13e is formed to have a slightly larger diameter than the other portions.

  Then, as shown in FIG. 7 (a), first, a plurality of cutters from the outside to the side where the niobium portion 13e is to be divided into, for example, three equal parts, are formed on the portion where the second protrusion 26c is to be formed. The tip of 27,27 is applied, and required depth is inserted. Next, as shown in FIG. 3B, the electrode shaft 13 and the cutters 27 and 27 are relatively moved in the axial direction to form the second protrusion 26c.

  Next, as shown in FIG. 7 (c), the first protrusion 26b is formed by a substantially similar method, but the relative relationship between the cutters 27 and 27 and the electrode shaft 13 when the second protrusion 26c is formed. By increasing the amount of movement in the axial direction, the amount of protrusion of the first protrusion 26b can be made larger than that of the second protrusion 26c. Thus, since the first and second protrusions 26b and 26c are formed by cutting and raising the niobium portion 13e, they are formed of a refractory metal.

  FIG. 8A is a front view of the electrode mount 13x, and FIG. 8B is a cross-sectional view of portions A and B of FIG.

  When the electrode mount 13x configured as described above is inserted into the small diameter cylindrical portions 21b and 21c from the opening end thereof as shown in FIG. 6B, the second protrusion 26c is formed. The projecting tip of the first projection 26b contacts the inner surface of the small-diameter cylindrical portions 21b and 21c as a contact portion, while the lower surface of the first protrusion 26b is seated and locked to the outer surfaces of the open ends of the small-diameter cylindrical portions 21b and 21c.

  Next, similarly to the first embodiment, when the outer end surfaces of the small-diameter cylindrical portions 21b and 21c are irradiated with laser light such as YAG laser from three directions in the vertical direction, the first and second protrusions 26b and 26c and the surrounding niobium portion 13e are heated, and the open end portions of the small-diameter cylindrical portions 21b and 21c are heated and melted by the radiant heat to form the sealing portions 23a and 23b as shown in FIG. 6C. Is done. Almost all or at least a part of the first and second projecting portions 26b and 26c are embedded as the locking portions 26 in the sealing portions 23a and 23b.

  Therefore, according to this electrode mount 13x, the same effect as the electrode mounts 13a and 13b can be obtained, and the first protrusion 26b of the electrode mount 13x can be formed from the inner diameters of the openings of the small-diameter cylindrical portions 21b and 21c. Therefore, the first protrusion 26b can be easily and surely locked by simply placing the first protrusion 26b on the outer end of the opening. For this reason, it is highly practical. In addition, since the tip of the second protrusion 26c, which is an example of the contact portion, is in contact with the inner surfaces of the small-diameter cylindrical portions 21b and 21c, a crack is caused by heat shock at the time of heating the open end portions of the small-diameter cylindrical portions 21b and 21c. C is formed. For this reason, the sealing parts 23a and 23b can be formed easily and quickly.

  FIG. 9A is a front view of an electrode mount 13y according to a second modification of the present invention, and FIG. 9B shows a longitudinal section of the electrode mount 13y, and the electrode mount 13y is placed in the small diameter cylindrical portions 21b and 21c. Shows the inserted state.

  As shown in FIG. 9 (b), the electrode mount 13y has a locking portion 26 composed of a plurality of bending rods 26d, 26d, and 26d, and the electrode shaft 13 is connected to a cermet as shown in FIG. 4 (c). 13d is deleted, and the niobium part 13e is formed in the deletion mark, thereby having a main feature in the point of construction.

  In other words, a plurality of bending rods 26d, 26d, and 26d are fixed to the outer peripheral surface of the boundary portion between the niobium portion 13e and the molybdenum portion 13c by welding so as to straddle between both the portions 13c and 13e.

  Each of the bending rods 26d, 26d, and 26d is made of a high melting point metal (Nb, Mo, Ta), and has a protruding portion 26da that protrudes in a U-shape in the axial middle portion of a straight round bar or square bar having a required diameter. Each of them is integrally bent and fixed by welding at a plurality of circumferentially equally divided positions (for example, three directions) of the outer peripheral surface of the niobium portion 13e.

  Therefore, as shown in FIG. 9B, when the insertion portion 24 is inserted into the pair of small-diameter cylindrical portions 21b and 21c from the opening ends, the electrode mount 13y has a lower end portion of each bending rod 26d. The outer surface of 26db comes into contact with the inner surfaces of the small diameter cylindrical portions 21b and 21c as contact portions, while each protruding portion 26da is seated and locked as an engaging portion 26 on the open end outer surface of the small diameter cylindrical portions 21b and 21c.

  Next, similarly to the first and second modified examples, when the outer end surfaces of the small-diameter cylindrical portions 21b and 21c are irradiated with laser light such as YAG laser from three directions in the vertical direction, a plurality of bent portions are formed. The rods 26d, 26d, and 26d and the niobium portion 13e in the periphery thereof are heated, and the open end portions of the small-diameter cylindrical portions 21b and 21c are heated and melted by the radiant heat, and as shown in FIG. 23b is formed. Almost all or at least a part of the plurality of bending rods 26d, 26d, and 26d are embedded as locking portions 26 in the sealing portions 23a and 23b.

  For this reason, according to this electrode mount 13y, the same effects as the electrode mounts 13a, 13b, and 13x can be obtained, and the small-diameter cylindrical portions 21b and 21c can be formed by the contact portions 26db of the bending rods 26d of the electrode mount 13y. It is possible to reduce both the formation time of the sealing portions 23a and 23b and the reduction in misalignment of the pair of electrodes 22a and 22b due to the cracks C generated at the time of heating and melting the openings.

  Further, since the outer surface of the contact portion 26db of each bending rod 26d is in contact with the inner peripheral surface of the small-diameter cylindrical portions 21b and 21c, the heating of the contact portion 26db is reduced in diameter when the bending rod 26d is heated by laser light irradiation. Heat is transferred to the tube portions 21b and 21c with high efficiency. Moreover, the crack C generate | occur | produces by the heat shock at the time of the heating. For this reason, the formation time of sealing part 23a, 23b formed in small diameter cylinder part 21b, 21c can be shortened.

  FIG. 10 is a schematic side view of the illumination device 31 according to the second embodiment of the present invention. This illuminating device 31 is an embedded illuminating device embedded in a ceiling 32, and has an instrument (device) main body 33 attached to the ceiling 32 side. A socket 34 is provided in the instrument (device) main body 33, and the base 14 of the high-pressure discharge lamp 1 shown in FIG. Further, a reflection mirror 35 for reflecting the radiated light of the high-pressure discharge lamp 1 downward in FIG. 8 is disposed in the instrument (device) main body 33. The cover made of glass or the like covers the opening side of the reflection mirror 35. A light control body 36 made of a member, a lens or the like is disposed.

  The high-pressure discharge lamp 1 is electrically connected to a lighting device (not shown) having an appliance (device) main body 33, the main body 33, or a ballast arranged separately from the main body 33, and the like. It can be turned on by supplying power.

  In addition, the lighting device is not limited to this embodiment, and may have other structures and uses. The lighting method is not limited to the one using the rectangular wave lighting circuit device, and a choke coil type, a transformer type, etc. A magnetic ballast may be used. In the arc tube 2, 2A according to the above embodiment, the electrode shafts 13 of the pair of electrode mounts 13a, 13b, 13y are formed in a rod shape having substantially the same diameter over the entire length, and the niobium portion 13e of the electrode shaft 13 is formed. However, the present invention is not limited to this. For example, the outer end portion of the niobium portion 13e extending outward from the pair of sealing portions 23a and 23b. In addition, a locking portion having a diameter larger than the opening diameter of the small diameter cylindrical portions 21b and 21c may be formed. According to this, it is possible to improve the positioning accuracy of the electrode mounts 13a, 13b, and 13y.

  DESCRIPTION OF SYMBOLS 1 ... High pressure discharge lamp, 2 ... Arc tube, 13a, 13b ... A pair of electrode mount (current introduction conductor), 21 ... Discharge vessel (translucent ceramic discharge vessel), 21b, 21c ... A pair of small diameter cylinder parts (opening) ), 22a, 22b ... a pair of electrodes, 23a, 23b ... a pair of sealing portions, 24 ... an insertion portion for electrode mount values, 26 ... a locking portion, 26a ... a thin rod for locking, 26b ... a first protrusion, 26c ... 2nd protrusion part (contact part), 26d ... bent bar, 26db ... insertion part (contact part) of bent bar.

Claims (4)

An enclosing portion surrounding the discharge space, and a translucent ceramic discharge vessel having an opening formed in the enclosing portion;
A pair of insertion portions inserted from the opening of the discharge vessel toward the enclosure, a pair of electrodes disposed at the inner ends of the pair of insertion portions and arranged to face each other with a predetermined inter-electrode distance; and A current-introducing conductor that is locked to the opening and includes a refractory metal locking portion that is locked to the opening of the discharge vessel and holds the predetermined distance between the electrodes;
A discharge medium enclosed in the discharge vessel;
The opening of the discharge vessel is heated and melted at a temperature at which the locking portion can be melted to seal at least a portion including the locking portion of the current introduction conductor to the opening, and the opening. A sealing part for sealing the part;
A high-pressure discharge lamp comprising: 2. The high-pressure discharge lamp according to claim 1, wherein the current introduction conductor is formed with a protrusion having a larger diameter than the inner diameter of the opening of the discharge vessel. The high-pressure discharge lamp according to claim 2, wherein the current introduction conductor is provided with a contact portion made of a refractory metal that comes into contact with an inner surface of the sealing portion planned portion of the opening. A lighting device body;
The high-pressure discharge lamp according to any one of claims 1 to 3, which is disposed in the lighting device body;
A lighting circuit for lighting the high-pressure discharge lamp;
An illumination device comprising:

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