WO2014012575A1 - High-pressure discharge lamp having glass solder-sealed feed-through - Google Patents

Description

description

HIGH-PRESSURE DISCHARGE LAMP WITH GLASS LOW-SEALED IMPLEMENTATION

Technical area

The invention is based on a high-pressure discharge lamp GE measure the preamble of claim 1. These are in particular metal halide lamps. Such lamps are in particular high-pressure discharge lamps with a ceramic discharge vessel for general lighting.

State of the art

EP 1 114 438 and WO 2006/077516 and WO 2008/075273 each disclose a high-pressure discharge lamp in which iridium is used for the sealing. The feedthrough is a pin or wire of iridium, with the pin sintered directly into the end of the ceramic discharge vessel. The wire is pushed as a helix on a core pin. However, these concepts have not proven themselves in practice.

 Presentation of the invention

It is an object of the present invention, bereitzu ^¬ provide a ^{high-pressure} discharge lamp according to the preamble of claim 1, which has a short overall length and which is easy to manufacture and has a sufficient life for commercial purposes de.

This object is achieved by the characterizing features of claim 1. An ^¬ . Particularly advantageous embodiments fin ^¬ the in the dependent claims.

Long lifetimes in ceramic lamps have hitherto been ensured by long capillaries at the ends, in which passages are seated, which usually have a front, halogen-resistant end made of Mo or W, and which has a rear end. own Nb or cermet. Although this technique is reliable, but consuming and long ver ^¬ linked to achieve the required low temperatures in the field of sealing. According to the invention an implementation is used, which can be eintei ^¬ lig or more parts. It is essential that at least one front, the discharge-facing portion is made of iridium, hereinafter referred to as iridium-containing portion. At a minimum, an essential part, more than 50% by weight of this section, should be iridium.

It can also be an alloy with iridium. It is possible that a rear, facing away from the discharge portion, in particular an outer end, as is known, is realized by a Nb-pin or a niobähnliches material. This means a material whose thermal ^expansion coefficient in the range 6 to 9 * 10 ^{~ 6} 1 / K and is high temperature stable. In particular, here Re and Ta instead of Nb or alloys based thereon is suitable.

The implementation is melted in a short capillary at the end of the discharge vessel by means of solder as known per se ^¬ . The electrode which is forwardly ^¬ is where the implementation is based on a shaft made of W, as in itself be ^¬ known. It has a head which may have a ball or a helix, as also previously known. Is novel that the implementation comprises at least one short before ^¬ more complete part of the iridium-containing portion which is at least partially surrounded by a sleeve of ceramic material, preferably is alumina. The passage is sealed by means of glass solder in the capillary.

Thus, the following goals can be achieved: Simple design and construction topology and unkom ^¬ pliziertes manufacturing of unsaturated ceramic high-pressure lamps with the use of standard manufacturing processes without an additional use of a pump and filling tube is required to melt closure.

Heretofore, iridium direct sintering has been used and, in addition, torch vessel mounted pump and fill tubes have been required for sealing and electrode delivery. This method requires its own Ferti ^¬ supply lines and special manufacturing method of the ceramic burner vessel, which includes the electrodes fitted with a ^¬.

It is used a number of design features to ensure a reproducible melting length of iridium lead wires symmetrical in both sides in a ceramic tube without side pump tube.

(A) Use of a micro-capillary, in the form of a sleeve, for the best possible filling of the tailpipe of the ceramic burner vessel, so the capillary, and for Füh ^¬ tion of the feedthrough wire.

(b) using a ceramic eutectic solder mixture containing substantially A1203 and Tm203. Here be ^¬ the proportion of Tm203 carries 30-95Gew-%, is preferably a range of 40-90 wt .-%, more preferably this proportion is 43-57 wt .-% Tm203.

 (c) compliance with dimensioning rules for the dimensions of the parts concerned.

(d) Production by means of IR heating melting process (eg laser or IR radiation melting). (a) Ceramic lamps can be processed on existing laser smelting lines. (b) When using Multi-wire feedthroughs, English referred to as multi-beach feed throughs, with entspre ^¬ chender dimensioning or iridium cermet with high IR content (> 50 vol -.% Ir) high-wattage unsatu- ceramic can Lamps are made. The technique as such is known for example from DE 42 42 123.

Preferably, the novel implementation of unsaturated metal halide lamps with highly stable HT solder (HT = high temperature) is used. This means a solder that only melts at at least 1550 ° C.

In particular, this implementation is a wire part or pencil made of iridium, pure or as Iridiumlegierung or iridium cermet. The sleeve of the bushing is made of ceramic, which is advantageously adapted to the material of the capillary, usually PCA, in terms of the thermal expansion coefficient. Preferably, the ceramic sleeve is a micro-capillary of high purity A1203.

Typical dimensions of the seal are:

Inner diameter ID of the capillary: 0.1 to 0.4 mm, a typical value is 0.31 mm.

Outer diameter OD of the capillary: range 0.25 to 1.5 mm, a typical value is 0.61 mm.

A typical length L of the sleeve is 2.5 mm, while L can move in a range of 0.1 to 5 mm. The end of the capillary and the glass solder filling of the gaps between the burner tube end and the sleeve outer wall have a typical dimension of 10 to 120 ym in the radial direction, typically 40 microns. The axial extent is in the range of 100ym-5000ym. Preferably a value of 600 ym to 2500 ym. The glass solder filling in the gap between the inner wall of the sleeve and the iridium-carrying part has a radial length of 10 to 120 ym, a typical value is 25 ym. The axial length is in a range of 100 ym-5000 ym. a typical value is 600 ym.

Is particularly preferred in conjunction with the iridium ent ^¬ holding performing a highly stable HT-lot, preferably a eutectic mixture is used based on an alumina thulium oxide mixture. HT stands for high temperature. In this case, a third component x may be admixed as an oxide, ie a mixture A1203 / Tm203 / X203. This makes it possible to achieve a particularly high purity of the burner interior. ^¬ advantageous way should be included in the solder Tm203 in a range between 30 and 70 wt .-%. Here, x is an element from the group of rare earths (SE) Er, Y, Sc alone or in combination of at least two elements of the group. A preferred fusing length is:

Minimum diameter MID of the feedthrough wire is typically 0.2 to 0.35 mm.

Maximum length of the feedthrough wire is typically 1 to 5 mm.

But it is not essential that the implementation has a circular cross-section. The shape of the end of the burner as Kurkapillare has before ^¬ Trains t the following dimensions:

Outer diameter is typically 0.8-2.6 mm, typical value is 1, 8 mm. _r

The length is typically 0.35-2.6 mm, a typical value is 1 mm.

The inner diameter ID of the capillary is preferably 0.3-1.5 mm, a typical value is 0.65 mm. The bore of the Kurzkapillare is filled with the through ^¬ guide member, and preferably a eutectic solder mixture.

A preferred eutectic solder mixture is Tm203-A1203 with 53 wt% A1203.

A critical point for determining the parameters of the end construction is the thermal mass of the Endenkonstrukti ^¬ on. For this purpose, the outer surface over the A ^¬ bed length should preferably be in a specific ratio V to the entire surface of the discharge vessel. The embedment length should typically be about 0.8 mm to 2 mm. That behaves ^¬ V nis the total surface of the discharge vessel to the outer surface of the ^fused-¬ is preferably 50 to 150, into ^¬ particular 60 to 90, based on a seal. Preferably, the absolute value of the outer surface of the Einschmelz ^¬ length in the range 2 to 6 mm ² . A typical safe value for the total length of the discharge vessel is 15 to 25 mm.

The ratio V therefore plays a role because the total surface ^¬ the thermal losses of the discharge ^vessel prevails ^¬ . In contrast, the cooling effect should be more pronounced in the area of the embedding length. In the above setting for V results in a thermal load situation high Stabi ^¬ quality, which allows very long lifetimes.

It is desirable that the glass solder be relatively low viscosity, which is why the mentioned composition is advantageous. This ensures, in particular, that the glass solder wets the capillaries completely up to the lower edge. In this consensus As a result, any harmful dead volume in the area of the capillary is avoided. Furthermore, a defined thermal transition between capillary and discharge volume is ensured, so that no undesirable scattering of light-technical properties can occur.

A preferred inner contour of the burner end includes a From ^¬ set or a nose which acts as a brake for the during manufacture low-viscosity glass solder.

For high-wattage lamps can advantageously be a so-called. Multi-wire system with a corresponding ceramic support member for guiding a certain number of iridium wires are used with adapted to the support member dimensions.

Another advantageous feature is a filling that is un saturated ^¬ . In principle, a typical filling of this type known per se can be used.

Overall, this results in a metal halide lamp, can be avoided with an additional filling tube, which causes a significant cost savings.

Typically, the closing of the discharge vessel or burner by means of laser or IR radiation can take place. Also heating spirals are possible.

Concrete fillings for unsaturated dimmable lamps are given below, typical molar concentrations for a filling having a color temperature of 3000 K are: At a power of 70 W, the discharge vessel has an inherent ^¬ res volume of typically 300 mm ^3. The filling used is:

NaJ: 2 + - 0.5 μmol / mm ³ or 0.3 + -0.075 μg / mm ³ ;

TU: 1.5 + - 1 μmol / mm ³ or 0.5 + -0.33 μg / mm ³ ; CeJ3: 0.1 + - 0.05 μmol / mm ³ or 0.053 + -0.026 μg / mm ³ ;

PrJ3: 0.025 +/- 0.025 μmol / mm ³ or 0.013 + 0.013 yg / mm ³ ;

CaJ2: 0.03 +/- 0.02 ymol / mm ^3, and 0.009 + -0.006 yg / mm ^3.

A typical molar concentration of metal halides for a filling achieving a color temperature of 4000 K is as follows, applied here as well to a power of 70W with an internal volume of the discharge vessel of 300 mm ³ : LiJ: 0.4 + - 0.15 μmol / mm ³ or 0.053 + - 0.02 yg / mm ³ ;

TU: 1.5 + - 1 μmol / mm ³ or 0.5 + -0.33 μg / mm ³ ;

DyJ3: 0.4 + - 0.15 μmol / mm ³ or 0.22 + -0.08 μg / mm ³ .

For Hg-containing lamps, a typical dosage of

Hg: 15-22 yg / mm ³ used. For setting an improved tungsten cycle, it may be advantageous to use HgJ2 as well. A typical molar concentration is

HgJ2: 0.3-1.5 g / mm ³ ; a typical value is 0.7 yg / mm ³ .

For Hg-free lamps, the typical mix used is the following mix of metal halides:

GaJ3: (typical 1.6) 0.5 to 4 yg / mm ³ ;

InJ: (typically 0.5) 0.3 ... 3 yg / mm ³ ;

ZnJ2: (type 2) 0.5 to 4 yg / mm ³ .

The end part of the bushing, which may be made of Nb or niobähnli-erhern material, and at least a portion the front section of Ir is sealed with a high temperature solder. This is a ^well-¬ tes se Lot, see for example WO 2005/124823 or in WO 2003/096377 disclosed iridium-containing solder. A

preferred embodiment is a solder, the oxides of the

 Aluminum and thulium and possibly additionally contains at least one oxide from the group erbium, yttrium, scandium. In particular, it is a eutectic

Mixture, which can also be described as a high-temperature frit.

The bushing is welded to the electrode.

In this case, at least the part of the leadthrough facing the Nb pin is preferably covered with the solder or the frit.

However, the solder can also cover a larger area of the front part.

The discharge vessel is preferably made of alumina such as PCA or the like. made, as known. It can have integral ends or separate plugs. Instead of Nb it is also possible to use another similar behaving material, in particular Ta or Re or a material whose thermal expansion coefficient differs by less than 20% from that of the Nb, referred to a temperature of 1100 K. You can also use a cermet. These materials are collectively called Nb material.

When filling an unsaturated filling USAGE ^¬ det preferred which is therefore entered in operating completely in the vapor phase ^¬.

Typical is a wattage of 70 to 150 W, the lamp shows high stability and good dimming properties. An Ir wire as a front section has been sintered directly into the capillary. However, the so far reali ^¬ sized lifetimes for a commercial application are too short. Preferably, a section, in particular a front part ^¬ piece, surrounded by a sleeve. The sleeve sits completely in the capillary. This leads to a stabilization of the orientation of the implementation. The trick here is to extend the melting-in length of the glass solder to the Ir pin. When using an unsaturated Hg-free filling is frits of the type have proved successful alumina / thulium oxide / aluminate and aluminum ^¬ miniumoxid / yttria particularly good. The melting is achieved, for example, by means of an IR laser or W helix heater.

 The sleeve in conjunction with a special glass solder is the key to keeping a high-temperature seal tight for a long time, using temperatures of at least 1550 ° C.

The discharge vessel is preferably bulbous, oval, elliptical, barrel-shaped or similar to a rugby ball shaped and in particular has a high aspect ratio of at least 2. Ty ^¬ pisch allows the novel sealing technique shortening the overall length of the discharge vessel compared to the usual capillary sealed by 30 bis 60%.

 Typical fillings include NaJ, CaJ2, and rare earth metals such as in particular CeJ3 and optionally PrJ3 and ErJ3. In addition, for example, HgJ2, TU and possibly MnJ2. Other halogens such as chlorine or bromine are suitable for the halides.

In the case of Hg-free lamps, ZnJ2, Inj, TU, NaJ and SEJ3 are used in particular as a filling, SE stands for rare earth metal. Xe is used as inert gas, in particular, alone or in combination with other noble gases, in particular argon.

In a preferred embodiment, an end face of the capillary is provided, which is arranged substantially transversely to the longitudinal axis of the discharge vessel. Preferably, it is 70-90 ° arranged thereto. In this case, this end face seen from the two ^¬ th outer gap should extend at least by a width D to the outside, the gap width S of the outer

In particular, D is at least 2S.

Essential features of the invention in the form of a numbered

List of proposals are: High-pressure discharge lamp, designed with a discharge vessel enclosing a discharge volume in which a filling is accommodated in the discharge volume of the discharge vessel is provided with an end which is tubular in the ^¬ particular as a capillary, and wherein in the end of a bushing is sealed by means of glass solder, wherein on the implementation, an electrode is attached, which protrudes into the discharge volume, characterized in that the implementation of a front, facing the discharge portion has at least which is made essentially of iridium, at least a wesentli ^¬ cher part of the front section within the end ver ^¬ runs and is surrounded by a sleeve of ceramic material, wherein a first inner and a second outer gap between the end and sleeve on the one hand and sleeve and Ir section on the other hand filled with glass solder. High-pressure discharge lamp according to proposal 1, characterized marked ^¬ characterized in that the Ir section and electrode are connected by butt welding. High-pressure discharge lamp according to proposal 1, characterized marked ^¬ characterized in that the implementation is pin-shaped. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that the glass solder extends from the end of the tube to at least a portion of the Ir section he ^¬ , preferably wherein the glass solder extends to an end face of the capillary. High-pressure discharge lamp according to claim 4, characterized marked ^¬ characterized in that the glass solder is at least up to a hemispherical portion of the front portion facing the rear portion.

6. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that the glass solder is a high-temperature solder based on oxides of aluminum and Tm203 and possibly further

Oxides of Rare Earth Metals He, Y, Sc is.

7. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that the filling comprises metal halides and in particular also comprises Hg. 8. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that a ratio between the total surface AT of the discharge vessel and the surface AL of the end in the region of the Einschmelzlänge along a longitudinal ^¬ axis of the discharge vessel in a range 50 to 150, advantageously 60 to 90 , lies.

9. High-pressure discharge lamp according to claim 7, characterized marked ^¬ characterized in that the filling is dosed unsaturated.

10. High-pressure discharge lamp according to claim 1, characterized ge ^¬ indicates that the implementation has a rear, facing away from the discharge second section, which is made of Nb or Ta or Re alone or in mixture.

characters

In the following the invention will be explained in more detail with reference to several embodiments. 1 shows a high-pressure discharge lamp with discharge vessel

Outer bulb; 2 shows a first embodiment for the range of from ^¬ seal at one end.

Fig. 3 shows a second embodiment of the field of

 Sealing at one end; Fig. 4 shows a third embodiment of the field of

 Sealing at one end.

Description of the drawings

FIG. 1 schematically shows a metal halide lamp 1. It consists of a discharge vessel 2 made of PCA into which two electrodes 3 are inserted. The discharge vessel has a central part 5 and two ends. There are two at the ends

Short-capillaries or tube sections 6. The lamp has a longitudinal axis A. ^¬

The discharge vessel 2 is surrounded by an outer bulb 7. The discharge vessel 2 is in the outer bulb by means of an overall stells which supported a short and a long power supply 8a and 8b be ^¬ tains. On the outer bulb sits a screw 9.

The discharge vessel contains a filling which typically comprises Hg (3 to 30 mg / cm ³ ) and 0.1 to 1 mg / cm ^{3 of} metal halides. As noble gas, argon is typically used under a pressure of 30 to 300 hPa cold.

Figure 2 shows a first embodiment of the end of the ceramic discharge vessel for the region of the seal on a pipe piece or a capillary 6. The electrode 3 with a head, which is formed as a helix 10, and a shaft 11 of W, is connected to a bushing 12 prepared from iridium and there butt-welded by laser (15). A sleeve 16 made of aluminum oxide surrounds the pin 12 made of Ir in Be ^¬ rich short capillary 6 so that between the short capillary tube and a first gap 17 and between the sleeve and pin of Ir a second gap 18 remains.

A high-temperature solder 19, preferably a eutectic mixture of aluminum oxide and Tm 2 O 3, is introduced into the capillary 6. crowded. It extends from the outside to the front end of the capillary. Externally, it forms on the Ir pin a Me ^¬ niskus. The glass solder 19 also fills the first and second gaps 17, 18 out to the front end.

In addition, outside of the axis A of the lamp, a stop 21 is attached to the Ir pin 12, so that the insertion depth of the pin is precisely defined. The butt 15 is equal ^¬ time as a stop for the sleeve 16, before it is finally fixed by the glass solder.

 Instead of a pure pin 12 of Ir, the implementation may also be in two parts, wherein an outer portion may be made of Nb or wherein for this rear portion and another Nb-like material according to the following Tab. 1 can be used. There, four metals are compared to PCA, including Ir. Given is the thermal expansion coefficient TAK at an operating temperature of 1130 K and the percentage difference of the TAK to Nb.

The outer gap usually has a width of 10 to 150 μm, preferably 30 to 100 μm, and the inner gap has a width of 3 to 50 μm, preferably 10 to 40 μm. the axial length of Ka ^¬ pillare is preferably 2.5 mm, the sleeve is as long and is flush with the capillary from. The diameter of the Ir pin is at least 0.2 mm, preferably 0.25 to 0.4 mm.

Figure 3 shows another embodiment in which the capillary 6 has on its inner wall in the vicinity of the opening to the discharge volume towards a nose 25 as a stopper for the glass solder 19. FIG. 4 shows a similar ^exemplary embodiment with a stopper system for the glass solder. The stopper system consists of a transverse to the longitudinal axis A running projection in the vicinity of the opening to the discharge volume. The projection may be mounted either on the side of the capillary 26, or on the side of Sleeve Shirt ^¬ se, 27, or on both sides.

The length of the melting zone AX, ie the axial region in which the solder extends at least into the capillary, is typically 0.8 to 4 mm. A typical value for a 100 W lamp is 1.5 to 2.5 mm.

The frits typically consist of mixtures of various rare earth oxides such as Tm203 together with aluminum oxide, where ^¬ can be mixed with other SE oxides.

The presented sealing technique is suitable for both Hg-containing and Hg-free fillings.

 The filling typically contains iodides of Na, Ce, Tm, Dy

and / or Tl as well as the Ca. Metal halides of other metals Me ^¬ are of course not excluded.

The lead-through system with the iridium-containing front section is particularly well suited, in particular for wattages of 150 to 1000 W.

 A particular advantage of the new closure technology is that it can be introduced on standard manufacturing machines. The sealing is done by closing by laser radiation.

Claims

claims 1. A high-pressure discharge lamp, designed with a discharge vessel enclosing a discharge volume in which a filling is accommodated in the discharge volume of the discharge vessel is provided with an end which is tubular in the ^¬ particular as a capillary, and wherein sealing a lead-through means of glass solder into the end is, wherein the implementation of an electrode is attached, which projects into the discharge volume, characterized in that the passage has at least one front, the discharge-facing portion which is made essentially of iridium, wherein at least one ^{wesentli ¬} cher part of the front Section inside the end ver ^¬ runs and is surrounded by a sleeve of ceramic material, wherein a first inner and a second outer gap between the end and sleeve on the one hand and sleeve and Ir section on the other hand filled with glass solder. 2. High-pressure discharge lamp according to claim 1, characterized marked ^¬ records that Ir section and electrode are connected by butt welding. 3. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that the implementation is pin-shaped. 4. A high-pressure discharge lamp according to claim 1, characterized characterized ^¬ marked in that the glass solder is at least a partial area of the Ir portion it extends from the end of the tube to ^¬, wherein preferably, the solder glass extending to an end face of the capillary extends. 5. High-pressure discharge lamp according to claim 4, characterized marked ^¬ characterized in that the glass solder extends at least to a hemispherical the rear portion facing portion of the front portion. 6. high-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that the glass solder is a high-temperature solder based on oxides of aluminum and Tm203 and optionally other oxides of the rare earth metals Er, Y, Sc. 7. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that the filling comprises metal halides and in particular also comprises Hg. 8. High-pressure discharge lamp according to claim 1, characterized marked ^¬ characterized in that a ratio between the total surface AT of the discharge vessel and the surface AL of the end in the region of the Einschmelzlänge along a longitudinal ^¬ axis of the discharge vessel in a range 50 to 150, advantageously 60 to 90 , lies. 9. High-pressure discharge lamp according to claim 7, characterized marked ^¬ characterized in that the filling is dosed unsaturated. 10. High-pressure discharge lamp according to claim 1, characterized ge ^¬ indicates that the implementation has a rear, facing away from the discharge second section, which is made of Nb or Ta or Re alone or in mixture.