JPS6115551B2 - - Google Patents

Description

Detailed Description of the Invention This invention houses an arc tube, a filament, and a bimetal switch heated by the filament in an outer tube, and starts the arc tube by applying a high voltage pulse based on the kick voltage of the bimetal switch to the arc tube. The present invention relates to a metal vapor discharge lamp.

For example, high-pressure sodium lamps have extremely high light efficiency compared to mercury lamps, so they are increasingly being used as a resource-saving light source, but their biggest drawback is their high starting voltage, which makes the starting method complicated. . The reason for this is that since it is not possible to use materials such as quartz glass for the arc tube bulb, bulbs made of translucent single crystal or polycrystalline materials, such as alumina ceramics and sapphire, are used, and as a result, they emit light like a mercury lamp. The problems include the inability to place an auxiliary electrode inside the tube bulb, and the fact that xenon gas is used to increase light efficiency, but xenon gas requires a high starting voltage.
Various improvements have been made in the past as means for lowering the above-mentioned starting voltage, but recently, a filament and a bimetal switch heated by the filament are housed together with the arc tube in the outer tube, and the filament and bimetal switch are are connected in series, and this series circuit is connected in parallel to the arc tube, and when the bimetallic switch is closed at room temperature during startup, electricity is applied to heat the filament, and this heat opens the bimetallic switch. A method is being adopted in which a high voltage pulse is applied to the arc tube due to the kick voltage at the time of opening, and this is superimposed on a sinusoidal voltage from an externally connected ballast, thereby lighting the bulb at a high starting voltage. According to this method, the high voltage pulse generated from the bimetal switch is extremely high, depending on the lamp rating, so there is no need for a special high voltage pulse generation means in the ballast, and the ballast for mercury lamps can be used instead. This allows for reliable starting.

However, when a filament and a bimetallic switch are housed in the outer tube in this way, it is desirable that the filament be a planar heating element in the shape of a blind or a W-shape in order to improve the heating efficiency of the bimetallic switch. Therefore, it is necessary to arrange one filament in a plane. In such an arrangement, it is known as a conventional method to hold the bent portion of the filament with an anchor wire, but this anchor wire must be planted in an insulator such as glass.
However, in this type of lamp, the inside of the outer bulb tends to be high temperature, and since the above-mentioned insulator is close to the filament, it is impossible to use soft glass, hard glass, or quartz glass as the insulator. It is necessary to use an insulating substrate made of a ceramic such as alumina or sapphire. However, since the melting temperature of such a ceramic insulating substrate is extremely high, it is not possible to implant the anchor wire in a softened state. Therefore, it is unavoidable to form a through hole in advance, insert the base end of the anchor wire into the through hole, and then insert the anchor wire. , this base end is bent at a right angle so that it can be hooked. However, because the anchor wire is made of molybdenum, it has poor workability.
It is difficult to bend at the right angle, and springback occurs during the bending process, so the anchor wire is not securely fixed to the ceramic insulating base.
Due to rattling and rotational displacement in the vertical and horizontal directions, the support of the filament became unstable, resulting in problems such as the filament vibrating significantly when vibrations were applied. If the filament vibrates, it will cause the filament to break, making it impossible to start or light the arc tube. Especially if the filament vibrates when it is energized, adjacent filaments will come into contact with each other, causing discharge, and this discharge will cause the filament to break. However, there is a drawback that accidents such as failure to start and lighting are more likely to occur.

This invention was made based on the above circumstances, and its purpose is to firmly fix the anchor wire to the insulating base so that it does not wobble even when subjected to vibrations, and to securely hold the filament. It is an object of the present invention to provide a metal vapor discharge lamp with a built-in filament that can be supported.

An embodiment of the present invention will be described below based on the drawings.

The drawing shows a high-pressure sodium lamp rated at 400W, with reference numeral 1 indicating an outer tube, 2 a cap attached to one end of the outer tube 1, and 3 an eyelet terminal provided on the cap 2. A stem 5 is attached to the end of the neck portion 4 of the outer tube 1.
is sealed, and this stem 5 has an internal conductor 6.
a and 6b are sealed. One internal conductor 6a
is connected to the base 2, and the other internal conductor 6b is connected to the eyelet terminal 3. Each of these internal conductors 6a and 6b is provided with a conductive support 7 that also serves as a part of the arc tube support member.
a, 7b are welded together, and the support 7a, which is connected to the base 2 via the internal conductor 6a, extends inside the outer tube 1 toward the other end, and connects to the small diameter top portion 8 formed at the tip of the outer tube 1. It is landed via elastic plates 9, 9. Conductive holders 10, 10 are attached to these supports 7a, 7b, respectively.
In this case, one end of one holder 10 is electrically connected to the other support 7b, and the other end is supported by one support 7a via an insulating glass tube 11. Between the holders 10 and 10, a light emitting tube 12 is located on the tube axis of the outer tube 1.
The spindle-shaped portion 1a formed between the neck portion 4 and the small-diameter top portion 8 is positioned within the spindle-shaped portion 1a. This arc tube 12 has an inner diameter of 8 mm and a total length of
The openings at both ends of an arc tube bulb 13 made of a 114 mm alumina ceramic tube are closed with caps 14, 14 made of niobium, tantalum, etc., and main electrodes 15a, 15b are attached to these caps 14, 14 so as to face each other. There is. These main electrodes 1
5a, 15b are electrically connected to the supports 7a, 7b via holders 10, 10.
In the arc tube bulb 13, predetermined amounts of mercury and sodium are filled as luminescent metals, and xenon gas of, for example, 300 torr is filled as a starting rare gas. A proximity conductor 16 is provided on the outside of such an arc tube 12. The proximal conductor 16 is made of a hard-to-melt metal such as tungsten, molybdenum, tantalum, etc., and has a long rod-like or foil-like shape, and in this embodiment, a molybdenum wire with a wire diameter of 0.5 mm is used. The proximity conductor 16 is disposed along the longitudinal direction of the arc tube 12 in contact with or very close to the outer surface of the arc tube bulb 13. One end of the proximal conductor 16 located on the base 2 side is close to the main electrode 15b located on the base 2 side, and the tip of a thermally responsive metal member, that is, a bimetal 17, is welded to this one end. The base end of this bimetal 17 is connected to the other main electrode 1 opposite to the main electrode 15b located on the base side.
It is welded to support 7a which is connected to support 5a. The other end of the proximal conductor 16 located on the valve top side is supported by a distal end portion of the support 7a, for example, a portion 7aa disposed perpendicular to the tube axis of the outer tube. This support means may be welded or the like, but in this embodiment, the third
As shown in the figure, the tip portion 7 of the support 7a
An Ω-shaped locking tool 18 is welded to aa, and this locking tool 18
The other end of the proximal conductor 16 is loosely inserted into a through hole 19 formed between the end portion 7aa of the support 7a, and the other end of the proximal conductor 16 can freely rotate and pivot within the through hole 19. It is designed to allow directional displacement.

Furthermore, within the outer tube 1, an insulating base 20 made of ceramic or the like is located within the neck portion 4 and is connected to the stem 5.
The base body 20 is provided with a filament 22 serving as a resistance heating element and a bimetal switch 23 heated by the filament 22. As shown in FIGS. 4 and 8, the filament 22 is made of, for example, a large number of coil bodies 24 arranged side by side along the tube axis direction in a blind-like manner.
4 are connected in series to form a planar heating element, and each coil body 24 is formed with a coil outer diameter of 1.5 to 2 mm, for example, and a coil length of 25 mm.
It is formed to a certain extent. And each coil body 24...
are arranged with an interval of about 2 mm from each other.
In order to arrange and configure each coil body 24 in this manner, an anchor wire 25 made of molybdenum is fixed to the base 20, and the coil body 24 is held by the tip of the anchor wire 25. . In this case, each anchor wire 25... is the fifth
It is fixed as shown in FIGS. 7 to 7. That is, the base body 20 has anchor wires 25...
Elongated holes 26 are formed at the mounting positions thereof so as to penetrate through the upper and lower surfaces. On the other hand, each base end of the anchor wire 25 is bent in advance into a substantially U-shape (hairpin shape), and this U-shaped bent base end 27
The dimension along the surface direction, that is, the width dimension m ₁ is formed in advance to be larger than the longitudinal opening dimension m ₂ of the elongated hole 26 (m ₁ >m ₂ ). Then, the U-shaped bent base end 27 is inserted into the elongated hole 26 from above, but in this case, the U-shaped bent base end 27 is inserted into the elongated hole 26 from above.
It is fitted into the elongated hole 26 by elastically deforming it so that it has a dimension of m ₂ . Then, since the U-shaped bent base end 27 elastically returns within the elongated hole 26, the pair of lines impact on both sides of the elongated hole 26 in the longitudinal direction.
Therefore, this elastic force causes the bent base end 27 to form the elongated hole 2.
6. After that, the U-shaped portion 27a protruding from the lower surface of the base body 20 is bent and the base body 2
The short bent end 27b that is placed on the bottom surface of the base 20 and protrudes from the top surface of the base 20, that is, the end opposite to the side extending to the filament 22, is bent and placed on the top surface of the base 20. In this way, the bent ends 27a and 27b are formed on the upper and lower surfaces of the base body 20, respectively.
Since the anchor wire 25 is attached to the base body 20
There is no displacement in the vertical direction, and since the U-shaped bent base end 27 snaps into the elongated hole 26, there is no wobbling. And if the bent end 27
Even if a and 27b are not properly bent at right angles, the U-shaped bent base end 27 is elastically engaged with the elongated hole 26, so that the friction prevents rattling.
In other words, the anchor wire 25 is fixed to the base body 20 by this elastic attachment, and the bent ends 27a and 27b on the upper and lower surfaces are simply prevented from being displaced in the vertical direction to the extent that they are prevented from coming off. It's good.

The ends of the anchor wires 25 erected on the insulating base 20 in this manner are wound around the bent portions of the filament 22, that is, between the coil bodies 24, and hold the filaments 22 in a blind shape. There is. As shown in FIG. 8, the filament 22 has a gap l ₁ =5 to 5 in the radial direction from the arc tube 12.
It is installed at a position separated by 10 mm,
The bimetal switch 23 is provided outside the filament 22 in the radial direction. The bimetal switch 23 has a thermally responsive piece, that is, a bimetal piece 29, welded to the upper end of a conductive support rod 28 that is supported through the base 20, and a tungsten movable contact rod 30 that extends downward is fixed to the tip of this bimetal piece 29. A fixed contact rod 32 made of tungsten and extending horizontally is arranged above the conductive support rod 31 that is supported through the base 20, and the contact between the movable contact rod 30 and the fixed contact rod 32 is established. A switching mechanism is constructed by separating the two. The bimetal piece 29 faces the filament 22 at a distance of about 10 mm from the filament ₂₂ , and is placed on the outside of the filament 22, i.e.
and the outer tube wall. Therefore, the bimetal switch 23 faces the arc tube 12 with the filament 22 in between, and eventually the arc tube 12
The filament 22 and the bimetallic pieces 29 of the bimetallic switch 23 are arranged in the above order in the radial direction perpendicular to the tube axis direction of the outer tube 1. Further, the contact point between the movable contact rod 30 and the fixed contact rod 32 is located within the neck portion 4 of the outer tube 1.
The boundary line L between the spindle-shaped portion 1a and the neck portion 4 in
- It is arranged so as to be offset toward the neck portion 4 side than L. In addition, the above bimetal switch 2
When the bimetal piece 29 of No. 3 is thermally deformed, it comes into contact with the inner wall surface of the outer tube 1, as shown by the imaginary line in FIG. That is, as will be described later, the heating from the filament 22 and the arc tube 1
The bimetal piece 29 is thermally deformed by the heating from the outer tube 1, and its movable contact rod 30 separates from the fixed contact rod 32, but the amount of thermal deformation is regulated by the contact with the inner wall surface of the outer tube 1. It is something that Further, one side surface of this bimetal piece 29, that is, the side surface on the inner wall surface side of the outer tube 1, is formed into a rough surface 33 as shown in FIG. This rough surface 33 is formed by sandblasting, dry honing, or chemically treating the bimetal piece 29 itself. Such filament 22 and bimetal switch 23 are
One end of the filament 22 and one conductive support rod 2
8, the filament 22 is connected in series as shown in FIG. It is connected in parallel to the arc tube 12 by means such as connecting to the conducting wire 6b.

The lamp having such a configuration is connected to a commercial power source via a ballast 34, as shown in FIG.

The operation of such a lamp will be explained.

Before starting, the inside of outer tube 1 is at room temperature, so
The proximity conductor 16 is in contact with the outer surface of the arc tube bulb 13, and the movable contact rod 30 provided on the bimetal piece 29 of the bimetal switch 23 is in contact with the fixed contact rod 3.
This bimetallic switch 23 is closed in contact with 2.

When the lamp is connected to a commercial power source via a ballast as shown in FIG. 7, the filament 21 is energized and generates heat. Further, the proximal conductor 16 that is in contact with the outer surface of the arc tube bulb 13 is kept at the same potential as the main electrode 15a that is separated from the base 2 side.
Since the end portion of No. 6 on the base 2 side is close to the main electrode 15b on the base 2 side, a steep potential gradient is generated in the vicinity of the main electrode 15b. The heat generated by the filament 21 grows and heats the bimetal switch 23,
When this bimetal switch 23 is opened, a high voltage pulse of several thousand volts is generated as a result of this opening operation, and this high voltage pulse is superimposed on the sinusoidal voltage of the commercial power supply as shown in Fig. 11. Then,
An extremely high starting voltage is applied between the opposing main electrodes 15a and 15b. At this time, the adjacent conductor 16
Since there is a large potential gradient between the main electrode 15b on the base side and the main electrode 15b on the base side, starting is performed when the above-mentioned high voltage, a starting voltage of about 2000 to 4000 V, is applied. In other words, because the kick voltage of the bimetal switch 23 is used as the starting voltage and the nearby conductor 16 creates a potential gradient, even if the lamp is filled with xenon gas of 200 torr or more, it will not be stable for normal mercury lamps. By using a power supply, it is possible to light the lamp with a commercial power supply of 200V or less.

When the lighting of the lamp started in this way becomes stable, the temperature of the arc tube bulb 13 rises, and this heat heats the bimetal 17 connected to the adjacent conductor 16, so that the bimetal 17 is heated as shown in the imaginary line in Fig. 2. It is curved to Therefore, the adjacent conductor 16 is separated from the arc tube bulb 13, and sodium ions are no longer attracted to the adjacent conductor 16 and react with the alumina tube, preventing blackening and reducing the light emitted from the bulb 13. The adjacent conductor 16 itself will not be thermally deformed. Bimetal 17 like this
One end of the proximal conductor 16 is separated from the arc tube 12 by a distal end 7aa of the support 7a.
Since the through hole 19 is loosely formed in the through hole 19, no torsional stress is generated in the adjacent conductor 16, and no axial expansion stress is generated due to thermal expansion. That is, since the other end of the proximal conductor 16 can freely move within the through hole 19, when swinging stress or extension stress is applied, the proximate conductor 16 moves freely in response to this stress, so that the proximal conductor 16 is not deformed.

On the other hand, in the bimetal switch 23, since the bimetal piece 29 is provided directly opposite the planar filament 22, the bimetal switch 23 easily receives the heat generated from the filament 22, so that the bimetal switch 23 has good thermal response. After the bimetallic switch 23 is opened, since the bimetallic switch 23 is relatively close to the filament 22, the residual heat of the filament 22 maintains the thermally deformed posture, keeping the bimetallic switch 23 open. are doing. Therefore, lighting of the arc tube 12 is stable, and the open state can be maintained until the arc tube 12 reaches a high temperature.

Then, as the temperature of the arc tube 12 increases, the heat from the arc tube 12 is transferred to the filament 2.
The bimetal switch 23 is radiated to the bimetal piece 29 through the gap between the two coil bodies 24.
can still remain open. In this open state, the tip of the bimetallic piece 29 is in contact with the inner wall surface of the outer tube 1, as shown by the imaginary line in FIG. 8, to prevent the bimetallic piece 29 from curving more than necessary. There is.

Then, when the lamp is turned off, arc tube 1
Since the heat dissipation from 2 is stopped, the bimetal switch 23 shifts to the closing operation. In this case, since the filament 22 is interposed between the bimetal piece 29 and the arc tube 12, the residual heat of the arc tube 12 is blocked by this filament 22, so the bimetal piece 29 The proportion of people affected by this is greatly reduced. Moreover, the bimetal piece 29 in the bimetal switch 22 is the outer tube 1.
Since it is in contact with the inner wall surface of the bimetal piece 29, the heat of the bimetal piece 29 is taken away by the outer tube 1, which is normally cooled by the outside air, and since one side of the bimetal piece 29 is formed into a rough surface 33, Luminous tube 1
The surface facing away from the bimetal piece 29 has a large surface area and has good heat dissipation, so that the temperature of the bimetal piece 29 itself is quickly lowered. Furthermore, since the bimetal piece 29 is in contact with the inner wall surface of the outer tube 1, it is prevented from curving more than necessary, and the return distance until the movable contact rod 30 contacts the fixed contact rod 32 is also restricted to a small value. ing. For this reason, the return operation of the bimetal switch 22 is performed extremely quickly, and the movable contact rod 30 is connected to the fixed contact rod 3 from the time the light goes out.
2, that is, the restart time is shortened. It has been confirmed that the restart time of the above embodiments is shortened to 4 to 6 minutes.

Furthermore, when the lamp is turned off in this manner, the bimetal 17 of the proximal conductor 16 also returns to its original state, so that the proximal conductor 16 comes into contact with the outer surface of the arc tube bulb 13, facilitating restarting.

In the lamp that functions as described above, the anchor wires 25 supporting the filament 22 are
The long hole 26 of the insulating base 20 is formed by bending the base end into a U-shape.
Since it is elastically attached to the anchor wire 25, the elastic friction prevents the anchor wire 25 from shaking.
Therefore, even if the filament 22 is subjected to vibration, the filament 22 is prevented from vibrating and is securely held. and anchor wire 25
Even if it cannot be bent at a proper right angle because it is difficult to process like molybdenum, the anchor wire 25 can be securely fixed by a strong impact. Furthermore, there is no problem such as rotation of the anchor wires 25. With such a configuration, there is an advantage that a plurality of anchor wires 25 can be simultaneously pressed and bent from above and below.

In the above embodiments, the filaments are arranged in a blind shape, but modifications such as forming the filaments in a W-shape are also possible.

Furthermore, although the above embodiments have been described with respect to high-pressure sodium lamps, the present invention is not limited thereto and can be applied to metal halide lamps and high-pressure mercury lamps, and is particularly applicable to high-pressure mercury lamps with built-in ballasts that use filaments as ballasts. can. Furthermore, although the above-mentioned embodiment shows an example of a structure in which a proximal conductor is provided, the present invention is of course applicable to a high-pressure metal vapor discharge lamp that does not use a proximal conductor.

According to the invention described in detail above, when supporting a filament on a heat-resistant and corrosion-resistant insulating base by an anchor wire, a long hole is formed in the insulating base and the proximal end of the anchor wire is pre-aligned with the length of the long hole. Bend it into a roughly U-shape that is wider than the direction,
The bent base end is inserted into the elongated hole and snap-fitted, and is bent at the upper and lower surfaces of the insulating base, respectively. According to this product, the approximately U-shaped bent base end of the anchor wire snaps into the elongated hole of the base, and this elastic locking prevents the anchor wire from wobbling, and also prevents the upper and lower ends from shaking. The bent part prevents the anchor wire from being pulled out from the base, and the proximal end inserted into the elongated hole prevents rotation, ensuring that the anchor wire is securely fixed even when subjected to vibrations, etc. The anchor wire does not shift and the filament is prevented from vibrating, making it possible to hold it firmly. Moreover, according to this method, even if there are a plurality of anchor wires, the bending process can be performed at one time by the pressurizing means, so there is an advantage that it does not require much time and effort.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a front view of a high-pressure sodium lamp, Fig. 2 is a diagram explaining the operation of the adjacent conductor and bimetal, and Fig. 3 is a cross section taken along the line in Fig. 1. 4 is a rear view of the main parts seen from the back side of FIG. 1, FIG. 5 is an exploded perspective view of the anchor wire and the insulating base, and FIG. 6 is a sectional view taken along the line - in FIG. 5. Figure 7 is its side view;
Fig. 8 is a view along the arrow line in Fig. 4, Fig. 9 is an enlarged plan view of the bimetal switch, and Fig. 10 is an enlarged plan view of the bimetal switch.
The figure is a lighting circuit diagram, and FIG. 11 is a characteristic diagram of starting voltage. DESCRIPTION OF SYMBOLS 1... Outer tube, 12... Arc tube, 13... Arc tube bulb, 16... Proximity conductor, 17... Bimetal, 20...
Insulating base, 22... filament, 23... bimetal, 25... anchor wire, 26... elongated hole, 27... U-shaped bent base end.

Claims (1)

[Claims] 1 A filament and a bimetal switch heated by the filament are housed together with the arc tube in the outer tube, and at the time of startup, the filament is energized and the bimetal switch is opened by the heat generated by the filament. The arc tube is started by applying a high voltage pulse to the arc tube, wherein the filament is attached to a heat-resistant and corrosion-resistant insulating substrate via an anchor wire, and when attached, forms a long hole, and the base end of the anchor wire is bent in advance into a substantially U-shape with a width larger than the longitudinal dimension of the long hole, and this U-shaped bent base end is A metal vapor discharge lamp characterized in that the metal vapor discharge lamp is inserted into the elongated hole and then bent at the upper and lower surfaces of the insulating base and fixed to the insulating base.