JPS58154157A - Metal vapor electric-discharge lamp - Google Patents

Abstract

PURPOSE:To reduce the starting voltage of a metal vapor electric-discharge lamp while maintaining the heat insulating effect of the end of the emission tube during the lighting of the lamp by positioning heat-shielding bodies, which are movable due to the deformation of a heat-responsive member, in such a manner that they are apart from the outer surface of the end of the emission tube during the non-lighting and that they come close to said outer surface during the lighting. CONSTITUTION:At the starting of a metal vapor electric-discharge lamp, in a starting unit 21, a bimetal switch is opened due to the heat of a tungsten filament, a kick voltage is added to the secondary voltage of a ballast so as to produce a high-voltage pulse, and thus produced high-voltage pulse is applied to electrodes 15a and 15b. Here, since the high-voltage pulse is applied to a near-by conductor 18 as well, a large electric-potential gradient is generated between the near-by conductor 18 and the base-side electrode 15b, and the starting of the lamp is facilitated. Heat-shielding bodies 17a and 17b, differently from the conventional ones, are positioned apart from the outer surface of the end 22 of an emission tube. Since they are not located near the electrode part as mentioned above, the intensity of an electric field produced between the electrode 15b and the near-by conductor 18 is not reduced by the heat-shielding body 17a or 17b. As a result, a sufficiently low starting voltage can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Invention Oa*] The present invention relates to a metal vapor discharge lamp having a heat shield at its end.

[Technical background of the invention]

Conventionally, metal vapor discharge lamps such as high-pressure sodium lamps, metal halide lamps, and mercury lamps have been equipped with a thermal shield on the outer surface of the end of the arc tube to increase the temperature of the coldest part of the arc tube and to increase the temperature of the luminescent metal enclosed. It is designed to increase vapor pressure and obtain good characteristics.

[Problems with background technology]

However, the thermal wrapper is attached to the end of the arc tube or is fixedly supported and cannot be moved. On the other hand, by providing a heat-reducing body,
The disadvantage is that the starting voltage of the lamp decreases, making it difficult to start. There are two reasons for this: One point is when the thermal link is a conductor, and at the time of starting TjIb, such a thermal shield is applied between the electrode on the side provided and the opposite electrode, or in relation to the starting auxiliary conductor. This is thought to be because electric field stiffness is reduced by the heat shield.

This phenomenon is most noticeable when the heat shield is set to the same potential as the side on which it is installed (nearby voltage 4k). The second point is.

The heat shield is generated regardless of whether it is a conductor or an insulator, and the enclosed metal tends to evaporate due to the hot wire shield immediately after the lamp starts, so if the lamp goes out immediately after starting, evaporation may occur. This is thought to be because the metal adheres to the inner wall of the arc tube near the electrode 1, and the electric field intensity decreases in the same way as described above due to this adhered metal.

In addition, if a hot wire shield is provided, there arises the disadvantage that not only the initial starting voltage increases, but also the starting voltage increases even during one lighting operation.

[Purpose of the invention]

The present invention has been made to address the above-mentioned drawbacks of the conventional art, and includes a thermal shield provided at the end of the arc tube.

An object of the present invention is to provide a metal vapor discharge lamp that can prevent an increase in starting voltage.

[Overview of the Invention]) 11 The present invention resides in a metal vapor discharge lamp in which a heat shield that is moved by a T-shaped thermally responsive member is arranged so as to be close to the outer surface when the lamp is not lit.

[Embodiments of the invention]

Hereinafter, nine embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a color rendering improved high pressure sodium lamp rated at 360 W. A stem 2 is sealed to the opening of an outer tube 1, and a base 3 is fitted to this sealed portion. This stem sk
The internal conductors 4m and 4b are sealed. One internal conductor J14m is connected to the threaded portion of the base 3, and the other internal conductor 4b is connected to the center terminal 5 of the base 3. These internal conductors 4m and 4bK are the conductive servo wires 6m and 6b that make up the mount, and the servo wires 651 are connected to the threaded part of the cap 3 via the internal conductor @6m. The outer tube 1 circle is guided toward the other end, and the small diameter top part 7 of this outer tube L is landed (tortured. These nabos) 6 m, 6
b K is attached with conductive holders 9m and 9b. In this case, one end of one holder (9m) has one sabot)
6aK via electrical insulating tube lO, and the other sabot) 6bK is electrically insulated 111It
and is supported.

An arc tube 11 is attached to the holders 9g and 9b so as to be positioned on the tube axis of the outer tube 1.

The arc tube 11 is, for example, an arc tube pulp 1 made of a translucent aluminum ceramic tube with an outer diameter IQ of 5 m and a total length of 94 mm.
The openings at both ends of 2 are closed by a closed body 13.13 made of heat-resistant, sodium-resistant niobium, tantalum, or the like. Attached to the closed base body 13.13 is an ionization support conductor 14.14, at least one of which resembles an exhaust pipe, and each support conductor 14.14 supports an electrode 15a, 15b. This supporting conductor 14.14 is held by the holders 9a, 9b. The arc tube pulp 12) qK is filled with sodium and mercury as luminescent metals and xenon gas as a starting rare gas. For example, an amalgam of 25 weights of sodium and 7531 weights of mercury has a total weight of 30
Akebono gas is sealed and the pressure of xenon gas is 3.
00 Torr.

At both ends of the arc tube 110, heat-responsive members such as bimetal strips 16 and 16 kl are connected to heat shields 17m and 17b.

Further, a proximity conductor 1B is provided on the outside of the 9 arc tube 11,
The proximal conductor 18 is made of, for example, molybdenum, tantalum, niobium, or stainless steel, and is formed into a long shape. The proximal conductor 18 is arranged, for example, so that its longitudinal direction is in the tube axis direction KG of the arc tube pulp 12, and the one located at the cap 3@ is the electrode 15b near the cap 3.
One end of the bimetallic piece 19 is welded to the tip of a bimetallic piece 19 serving as a thermally responsive member. The base end of this bimetal piece 190 is connected to the above-mentioned electrode 61 (a support that maintains the same potential as the other electrode 15m facing 115b)! *Has been done. The other end of the proximal conductor l& is bent into an L-shape, and its tip is freely inserted into a ring 29 provided at the tip of the support 6aO.

Such a conductor 18 is in contact with the outward S side of the arc tube pulp 12 in the room temperature state III when the lamp is not lit, but after the lamp is started, the bimetal piece 19 is touched by the heat from the arc tube. It is heated and deformed, so that the adjacent conductor 18 can be removed from the arc tube loop 12.

A starter unit 21 is provided within the outer tube 1 adjacent to the neck portion. Although the starting unit 21 is not shown in FIG. 1, it is made up of a series circuit consisting of, for example, a tungsten filament and a bimetal switch, and this series circuit is electrically connected to the arc tube 11. They are 8-digited so that they are parallel.

Furthermore, the movable thermal shield, which is part g1 of the present invention, will be explained with reference to FIGS. 2 and 3. Figure 2 shows the foreshadowing when the light is not lit, and shows a pair of bimetallic strips 14i1.161) with one end tied to the electrode support conductor 14, and the other half of which is a semi-cylindrical thermal wire made of tantalum, niobium, etc. Shield bodies 17m and 17b are fitted, respectively, and these heat shield bodies 17a and 17b are located apart from the outer surface w4 of the arc tube end s22.

Therefore, the heat shields 17a, 17b explain to the nearby electrode machine the operation of a high pressure sodium lamp of such a configuration. At the time of starting, the bimetal switch of the starting unit 21 is opened by the heat generated by the tungsten filament, and the kick voltage is added to the secondary voltage of the ballast.
A high voltage pulse is generated, and this high voltage pulse is applied to the electrode 151.15bK. At this time, since the high voltage pulse is also applied to the proximal conductor 18, a large potential gradient is generated between the proximal conductor 18 and the electrode 15b on the base side, thereby facilitating starting. By the way, in this case, unlike the conventional one, the heat shielding body 171.17b is located at a distance from the outside 11ifi of the arc tube end 22, and is not near the electrode part, so that the heat shielding body 171.17b is located between the electrode 15b and the adjacent conductor 18. The electric field strength does not decrease due to the heat shield, and therefore a sufficiently low starting voltage can be obtained.

When the arc tube 11 moves to the stable point □ light, the bimetal strips 16m and 16b receive heat from the 9 arc tubes 11 and are bent into a curved shape 5 as shown in FIG.
, 17b are changed in position so as to be close to and surround the outer surface of the arc tube end 22 near the electrode section.

This allows it to function as a heat ray shield to keep the end of the tube warm.

Figure 4 shows the collected data of the starting voltage distribution and its changes during its life for 20 lamps of the present invention and 20 conventional lamps (with a heat shield fixed to the end of the arc tube) in the above example. Yes, the vertical axis is the starting voltage O, the horizontal axis is the lighting time, the arrow is the distribution OVa, the curve 1 is the average value for each lighting time, the curved edge B is the lamp of the present invention, *C is the lamp of the present invention. Conventional lamps are shown respectively.

As is clear from the figure, the starting voltage of the lamp of the present invention is approximately 600V lower during the lighting stage than that of the conventional lamp, and there is almost no increase in the starting voltage during the lamp's life. There is a trend that is becoming more and more widespread.

Its effects are quite impressive.

By the way, in this embodiment, the thermal shielding body is shown to have a voltage of - and - potential in its vicinity, but this means that the starting voltage decreases more heavily in such a configuration than in the conventional configuration. It's for a reason. However, the effects of the present invention can be obtained even if the thermal shield is a floating conductor or an insulator. That is, in the case of a conductor, as in the case described above, this is because the reduction in electric field intensity due to electricity and K is prevented by the heat shield.

Next, referring to FIGS. 5 and 6 for another embodiment, the electrode support conductor is indicated by 14. However, in the case of this embodiment, the bimetal strips 23m and 23b are extended to 24m and 24b.The other end of the lever 24 is connected to the horizontal bar 251K, and the other end of the lever 24b is connected to the horizontal bar 26bK. do.

One end of the horizontal bar 25m is connected to a cylindrical heat release body 26.

The other end is connected to an electrically insulating cylindrical tube 27. This cylinder t27 is made movable.

Similarly, the horizontal bar 25b is connected to the cylindrical thermal shield 26 and the electrically insulating cylindrical tube 27b [and one or both of the cylindrical tubes 2gm, 281) is extended to the other end of the arc tube, These bottles can also be configured to act as supports for arc tubes. The cylindrical heat shield 26 is located above and apart from the outer 11 surface of the arc tube end @22.

When the arc tube 11 shifts to stable lighting, the bimetal strips 23a and 23b receive heat from the arc tube 11 and bend downward as shown in FIG.
is pulled down to the outside 111 near the ionized part of the arc tube end 22.
+ [c It can be moved to a position adjacent to Kinki, and can fully perform the function of keeping the end of the tube warm as a heat ray shield. In this case as well, a sufficiently high starting voltage can be obtained as in the above embodiment.

Furthermore, as another example, an alumina ceramic tube with an outer diameter of 12.0 mm and a total length of 71 mm is filled with amalgam containing 25 mm of sodium and 20 mm of xenon gas as a starting rare gas.
Regarding the 400W color rendering improved high-pressure sodium lamp, which is lit by a special ballast with a built-in pulse voltage generator without installing the Torr-filled arc tube (21), Diagram 7 shows the results of measuring the distribution of starting voltage and the change in hit rate for 20 lamps of the present invention to which a transparent body was applied and 20 conventional lamps. In the figure, the vertical axis is the starting voltage (■), the horizontal axis is the lighting time, and the arrow is the range of the distribution.The zero curve connects the average values at each lighting time.Curve 1 is the lamp of the present invention, and curve C1 is the conventional lamp. Each lamp is shown.

As can be seen from the figure, the lamp of the present invention exhibits an average decrease of 3 GOV in starting voltage compared to the conventional lamp.

Moreover, there was almost no increase during the lifespan. The reason why this embodiment has a comparatively smaller effect, that is, the rate of reduction in starting voltage, than the above-mentioned embodiment in which the adjacent conductor is provided is that the electric field strength itself is 41 A compared to the case where the adjacent conductor is provided. h /
j、Aie、、、）：：：iえ、□6゜In addition, each of the above embodiments uses a high pressure)+7 Um lamp was described, but the present invention is determined by this, but it is not O, but a mercury lamp. It can also be applied to other metal vapor discharge lamps such as metal halide lamps.

〔Effect of the invention〕

As described in detail above, the present invention provides a metal vapor discharge lamp in which a thermal wrapper that is movable by deformation of the thermally responsive member is provided from the outer wall surface of the end of the arc tube when the lamp is not lit. Since it is arranged close to the outside 1111, it is possible to achieve the effect of lowering the starting voltage and making starting easier while maintaining the heat insulation effect of the end of the arc tube during lighting.

[Brief explanation of the drawing]

Figure 1 is a front view of an embodiment of the present invention, Figure 2 and Iris 3 are
- indicates the 12th part, and Fig. 2 shows the 3rd part when the light is not lit.
The figures show the lights when they are lit. FIG. 4 shows the characteristic ratio between the lamp of the present invention and the conventional lamp in the case of the Joki implementation. Figures 5 and 6 show the arrangement of other embodiments. Figure 5 shows 9 parts, non-lighting*, and Figure 6 shows lighting *1. FIG. 7 is a comparison diagram of the present invention 2/P of the other embodiment described above and the conventional lamp. l...Outer tube, 11-...Earth tube, 1
2... Arc tube pulp, 15! , 15b...
...electrode, 16a, 16b...bimetal strip, 17Ji, 17b...semi-cylindrical thermal wrapper. 22... Arc tube end, 2311, 23b.
... Bimetal strip, 26 ... Cylindrical heat ray body representative Patent attorney Noriyuki Chika (1 person)

Claims (1)

[Scope of Claims] 0) A luminescent tube having a pair of opposing electrodes on both sides 4 and a luminescent metal and a starting gas sealed therein, and a heat shield that moves due to the deformation of the thermally responsive member. The above heat shielding body is located at #II bit from the outside of the end of the arc tube when the light is not lit, and 141 itlK outside the above when the light is on.
A metal vapor discharge lamp characterized in that the lamps are arranged close to each other. (23) A metal vapor discharge lamp according to claim (1), characterized in that the arc tube is provided with a proximal conductor on its outer wall. Paragraph 181 (1) or Article 21 (21) Metal vapor discharge lamps with a bulk arrangement.