CN201298530Y

CN201298530Y - Discharge electrode of metal halide lamp

Info

Publication number: CN201298530Y
Application number: CNU2008201861807U
Authority: CN
Inventors: 钱峰
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-10-14
Filing date: 2008-10-14
Publication date: 2009-08-26
Anticipated expiration: 2018-10-14

Abstract

The utility model relates to a metal halide lamp, in particular to a discharge electrode of a metal halide lamp, which is provided with an electrode core rod, wherein the electrode core rod is welded with a molybdenum sheet and is a thoriated tungsten rod containing 2 percent of ThO2 by weight percentage; an electrode head formed by tightly winding 8 rounds of pure tungsten filaments as an outer ring and 10 rounds of pure tungsten filaments as an inner ring is arranged at one end of the electrode core rod, the spiral length of the electrode head extending out of the tungsten filaments is 2 mm, and the other end of the electrode head is squeezed and sealed with the molybdenum sheet. The discharge electrode has the advantages of strong current carrying capacity, short transfer time from glow discharge to arc discharge and high starting speed, avoids the early failure of a bulb and improves the service life of the bulb.

Description

Gold-halogen lamp discharging electrode

Technical field

The utility model relates to a kind of Metal halogen lamp, especially a kind of gold-halogen lamp discharging electrode.

Background technology

The market demand of now big electric current, high-power Metal halogen lamp is increasing, under big electric current, it is the key of problem that electrode in the assurance electric arc tube is worked reliably and with long-term, because electrode is the core component of electric arc tube, if the improper meeting of electrode design causes starting difficulty, early stage blackout or the like causes bulb early failure.Electrode mainly is that emitting electrons is to keep the carrying out of discharge in electric arc tube.Its major requirement is that work function is little, and chemical stability will be got well, and evaporation and sputter are little.The electrode material that reaches at present good result of use in Metal halogen lamp is a thorium tungsten bar, other materials or easy and metal halide chemically reactive, and perhaps work function is undesirable, perhaps evaporation, sputter is serious, perhaps has radial pattern, perhaps difficult processing all is not widely adopted.But the time usually there are following principal contradictions in electrode in work: be difficult to reach balance the loss of emission position thorium and thorium additional, the thermal capacity design of electrode should brightness arc transfer process want fast, and sputter is again little.In order to solve these contradiction, need a kind of new electrode of design.

The utility model content

The technical problems to be solved in the utility model is: in order to solve some contradictions that electrode work usually exists, the utility model provides a kind of gold-halogen lamp discharging electrode.

The technical scheme that its technical problem that solves the utility model adopts is: a kind of gold-halogen lamp discharging electrode, have the electrode core bar that welds together with molybdenum sheet, and the electrode core bar is for containing ThO ₂The thorium tungsten bar of weight ratio 2%, electrode core bar one end be close outside the pure tungsten silk 10 electrode tips that enclose in 8 circles, and electrode tip to stretch out tungsten filament helix length be 2mm, the other end and molybdenum sheet sealed crush.

Further, the diameter of phi≤1.5mm of electrode core bar.

Electrode core bar and molybdenum sheet spot welding end polish up and down, and top and bottom respectively grind off 0.3mm, and polishing length is 8mm.Electrode core bar spot welding end is carried out part polish processing, promptly increased the thickness of quartz glass, improved the resisting expansion strength of quartz glass, increased the contact area of electrode and molybdenum sheet again, improved the handling capacity of electric current.

In order further to improve the handling capacity of electric current, the electrode other end and the overlapping 1.5mm of molybdenum sheet weld adopt tantalum piece transition welding.

The beneficial effects of the utility model are: use this sparking electrode, the electric current handling capacity is strong, and the aura transformation time is short, starts soon, has avoided the early failure of bulb, the useful life of having improved bulb.

Description of drawings

Below in conjunction with drawings and Examples the utility model is further specified.

Fig. 1 is that electrode is arranged on the structural representation in the electric arc tube.

Fig. 2 is an electrode and the enlarged diagram that is connected of molybdenum sheet.

Among the figure: 1. electrode core bar, 2. electrode tip, 3. molybdenum sheet, 4. spot welding end, 5. electric arc tube.

Embodiment

As shown in Figure 1, 2, a kind of gold-halogen lamp discharging electrode has the electrode core bar 1 that welds together with molybdenum sheet 3, and electrode core bar 1 is for containing ThO ₂The thorium tungsten bar of weight ratio 2%, electrode core bar 1 one ends be close outside the pure tungsten silk 10 electrode tips 2 that enclose in 8 circles, and electrode tip 2 to stretch out tungsten filament helix length be 2mm, the other end and molybdenum sheet 3 sealed crush.The electrode tip of this electrode core bar is that discharge end stretches in the discharge cavity of electric arc tube 5, and its emitting electrons is in order to keep the carrying out of discharge.

The diameter of this electrode core bar 1 is according to formula

D = \sqrt{0.4 {XI}_{1}}

Calculate, the bulb operating current is when 10.3A, and electrode core bar 1 diameter is suitable about 2mm.But consider that electrode 1 core bar diameter is excessive, can start later stage of lamp and cause difficulty, and the time that the aura of the excessive start-up course of electrode core bar 1 diameter is converted to arc light will extend, can cause the blackout degree of lamp to be aggravated on the contrary.Through overtesting, electrode core bar 1 diameter that we choose be Φ 1.5 contain the Th02 weight ratio about 2% thorium tungsten bar, best results.

Though, the diameter of core bar reduces, but in the burning-point process for quartz ampoule bulb behind press seal of δ 1.5 left and right sides wall thickness, because the compression strength of quartz glass is about 1000 times of tensile strength, therefore the electric arc tube tensile strength made of quartz glass, claiming antidetonation strength again, is a very important index.Will consider when the design electrode: the quartz glass of the electrode cores shank diameter coated outside of Φ 1.5 will approach than the quartz glass of operating current in metal halogen lamp pole core bar (generally getting the thorium tungsten bar of Φ about the 1.25) outer wrapping of the 1KW of other patterns about 4.2A on the one hand, tensile strength is little, it is higher that the operating current that the Metal halogen lamp of 10.3A operating current is bigger causes the temperature of core bar on the other hand, cause the expansion rate of thorium tungsten bar to want high, the tensile stress that affacts on the quartz glass press seal face will be greatly.

As shown in Figure 2, therefore, be the spot welding end 4 of electrode core bar 1 and molybdenum sheet 3 that the press seal end polishes up and down, top and bottom respectively grind off 0.3mm, and polishing length is 8mm.So both increase the thickness of quartz glass, improved the resisting expansion strength of quartz glass, increased the contact area of electrode and molybdenum sheet again, improved the handling capacity of electric current.In order further to improve the handling capacity of electric current, the overlapping weld of electrode core bar 1 other end and molybdenum sheet 1.5mm adopts tantalum piece transition welding.

Claims

1. gold-halogen lamp discharging electrode, it is characterized in that: have the electrode core bar (1) that welds together with molybdenum sheet (3), electrode core bar (1) is a thorium tungsten bar, electrode core bar (1) one end be close outside the pure tungsten silk 10 electrode tips (2) that enclose in 8 circles, and it is 2mm that electrode tip (2) stretches out tungsten filament helix length, the other end and molybdenum sheet (3) sealed crush.

2. a kind of gold-halogen lamp discharging electrode according to claim 1 is characterized in that: the diameter of phi≤1.5mm of described electrode core bar (1).

3. a kind of gold-halogen lamp discharging electrode according to claim 1 is characterized in that: the spot welding end (4) of described electrode core bar (1) and molybdenum sheet (3) polishes up and down, and top and bottom respectively grind off 0.3mm, and polishing length is 8mm.

4. a kind of gold-halogen lamp discharging electrode according to claim 1 is characterized in that: described electrode core bar (1) other end and the overlapping 1.5mm of molybdenum sheet (3) weld, adopt tantalum piece transition welding.