JPH04141943A - Ceramic discharge lamp - Google Patents

Abstract

PURPOSE:To ensure the storing of an emission tube in an outer tube by supporting a straight tube part of the emission tube through a supporting member fixed by an electricity lead sealed in the sealing part of the outer tube. CONSTITUTION:An outer tube 4 for storing an emission tube 1 is made of, for example, quartz, and a squeezing sealed part 5 for sealing the inner part airtight, is formed on one end part of the outer tube, and an electricity lead 6 made of heat resisting metal such as stainless, which is electrically connected to an electrode through a niobium tube 2, is sealed in the squeezing sealed part 5. A supporting member 8 made of metal wire such as stainless is wound around a strait tube part 1a of the emission tube 1, and the end part of the supporting member 8 is welded to the electricity lead 6, and is thus fixed thereto. Since the straight tube part 1a of the emission tube is supported by the supporting member 8 fixed by an electricity lead 6 sealed in the sealing part 5 of the outer tube 4, the emission tube is surely fixed and supported and is thus stored in the outer tube.

Description

DETAILED DESCRIPTION OF THE INVENTION OBJECTS OF THE INVENTION (Industrial Field of Application) The present invention relates to a ceramic discharge lamp, such as a high-pressure sodium lamp, having a curved portion.

(Prior Art) For example, in a high-pressure sodium lamp, electrodes are hermetically sealed at both ends of an arc tube made of a translucent alumina tube, and inside the arc tube are sodium as a luminescent material, mercury as a buffer metal, and diluted starting material. It is constructed by sealing gas.

A translucent alumina tube has excellent heat resistance and corrosion resistance against sodium, and is therefore suitable for the arc tube of this type of high-pressure sodium lamp.

However, since translucent alumina tubes are made of ordinary glass and blades, they do not easily soften even at high temperatures, so conventionally, straight tubes formed by extrusion molding have been used as bulbs, and therefore arc tubes have a straight tube shape. I am doing it.

By the way, there is a recent tendency for high-pressure metal vapor discharge lamps to be used as light sources for indoor lighting, and therefore there is a demand for miniaturization of the lamps.

Reducing the size of the arc tube is an important issue in downsizing the high-pressure sodium lamps mentioned above, and one of the countermeasures is to make the bulb curved in the middle, such as in a U-shape or a U-shape. Conceivable.

When the arc tube is formed into a curved shape, even if the distance between the electrodes is kept the same as in the past, the space can be made smaller, and foreign capital can be made smaller.

(Problem to be Solved by the Invention (m)) By the way, when an arc tube is housed in an outer envelope, a method is usually adopted in which a pair of electrical lead-in wires of the arc tube also serve as supporting members for the arc tube. For example, in the case of an arc tube with a curved part such as a U-shape, these pairs of electrical lead-in wires are located in approximately the same direction, making it difficult to securely support the arc tube. become.

In other words, in the case of a conventional straight arc tube, a pair of electrical lead-in wires are led out in substantially opposite directions, so if the electrical lead-in wires are fixed to a metal support frame such as a mount, the arc tube The arc tube is suspended on the metal support frame, and the arc tube can be securely fixed and supported within the outer bulb. However, as described in 1., in the case of a curved arc tube, the pair of electrical lead-in wires must be in approximately the same direction. 1. Use this electrical lead-in wire to support the arc tube. In this case, there is a problem that the arc tube cannot be securely supported in a so-called one-sided supported state.

The present invention has been made based on the above circumstances, and is capable of reliably fixing and supporting an arc tube in which a curved portion is formed within an outer tube. The aim is to provide a ceramic discharge lamp that can be accommodated in

[Structure of the Invention] (Means for Solving the Problems) In order to solve the above problems, the ceramic lamp of the present invention has an outer tube having an airtight sealing part, a straight pipe part and this. Electrodes are sealed at both ends of a translucent ceramic tube in which a curved portion is formed continuously from a straight tube portion, and are connected to an electrical introduction body sealed to a sealed portion of the outer tube. The present invention is a ceramic discharge lamp with a small arc tube, and is characterized in that the i-tube portion of the arc tube is supported by a support member fixed to an electricity introducing body.

(Function) In the present invention, since the straight tube part of the arc tube is supported by a support member that is sealed to the sealing part of the outer tube and fixed by the electric introduction body, the arc tube can be removed from the It can be securely fixed and supported within the pipe.

(Example) An embodiment of the present invention will be described in detail with reference to the drawings.

As shown in the drawings of the high-pressure sodium lamp according to the present invention, the arc tube 1 has an inner diameter of about 7.25 mm and an average outer diameter of about 8 mm.
．． As shown in the figure, it is made of a translucent alumina tube of 75 mm, and has a straight pipe part 1a and a curved part 1b continuous to the straight pipe part 1a.
For example, it is formed into a U-shaped shape.

This arc tube 1. The openings at both ends are closed with ceramic disks (not shown) to which niobium tycope 2 is attached.

Further, a pair of electrodes 3 are each fitted into the niobium tube 2 and sealed within the arc tube 1.

Here, in this arc tube 1, the distance between the electrodes passing on the bulb center line is about 90 mm, the curvature passing through the center of the curved part 1b is about 7.5 mm, and the height of the arc tube 1 is about 40 mm. is set to .

Inside this arc tube 1, the sodium ratio is 10 to 25.
Storium amalgam with a weight ratio of 20 to 700 Torr and gysenon gas as a starting rare gas are sealed.

The outer tube 4 that houses the arc tube 1 is made of quartz glass, for example, and has a crushing sealing section 5 formed at one end to airtightly seal the inside, and is further provided with an electrode via a niobium coop 2. An electricity introducing member 6 made of a heat-resistant metal such as stainless steel 3 and electrically connected to the crushing sealing portion 5 is sealed to the crushing sealing portion 5 .

Further, the inside of the outer tube 4 is filled with an inert gas such as argon, krypton, xenon, nitrogen, etc. at a pressure of about 15 to 500 Torr.

Incidentally, a base base 7 made of ceramic or the like is mounted around the crushing sealing part 5.

[Straddling the arc tube 1, both ends of the arc tube 1 are directed toward the crushing sealing portion 5 of the outer tube 4, and the curved portion 1b is accommodated toward the bulb top side of the outer tube 4.

Further, a support member 8 made of metal wire, such as stainless steel, is wound around the straight tube portion 1a of the arc tube 1, and the end of this support member 8 is welded and fixed to the aforementioned electricity introducing body 6. ing.

When a drop test was conducted on a discharge lamp having the above structure, no damage occurred to the arc tube or outer bulb.

On the other hand, when similar discharge lamps without the support member 8 were tested under the same conditions, some of the arc tubes and outer tubes were damaged.

As described above, in the case where the support member shown in the example is attached, the movement of the arc tube is restricted by the support member even if it receives an impact when dropped, so the arc tube, etc. It was confirmed that no damage occurred.

According to the embodiment described above, since the straight tube portion 1a of the arc tube is supported by the support member 8 fixed by the electricity introduction member 6 sealed to the sealing portion 5 of the outer tube 4, the light emitted The tube can be reliably fixedly supported and accommodated within the outer tube.

In addition, since discharge occurs by connecting the shortest path between the electrodes, in the case of an arc tube with a curved part, the temperature of the curved part becomes high, and there is a significant temperature difference between the inside and outside of the curved part. If a support member is attached to this curved portion, there is a risk that cracks in the arc tube tube due to the temperature difference between the arc tube tube and its support member will increase. In the case where the support member 8 is attached to the straight pipe part 1a, the pipe wall temperature of the straight pipe part 1a is
b and the temperature difference in the circumferential direction of the straight tube portion 1a is small, which also has the effect of preventing the increase of cracks in the arc tube tube.

In addition, in the above embodiment, regarding the shape of the arc tube,
Although a U-shaped structure has been described, the present invention is not limited to this. For example, any structure having a curved portion such as a W-shaped or U-shaped bent portion can be applied to the above embodiments. can be applied in the same way.

[Effects of the Invention] According to the present invention described above, since the straight tube part of the arc tube is supported by the support member fixed by the electricity introducing body sealed to the sealing part of the outer tube, the light emission is not possible. The tube can be reliably fixedly supported and accommodated within the outer tube.

[Brief explanation of the drawing]

The drawing is a schematic diagram showing a high-pressure sodium lamp according to an embodiment of the present invention. 1... Arc tube 1a... Straight tube part 1b
...Curved portion 2...Niobium tube 3...Electrode 4...Outer tube 5
...Sealing part 6-...Electrical introduction body 7...Base base 8...Patent attorney representing support member Ono 1) Yoshihiro

Claims (1)

[Scope of Claims] An outer tube having an airtight sealing portion, a straight tube portion, and a translucent ceramic tube having a curved portion continuous to the straight tube portion are provided with the above-mentioned at both ends thereof. A ceramic discharge lamp comprising an electricity introducing body sealed in a sealing part and an arc tube in which a connected electrode is sealed and housed in the outer bulb, wherein the straight tube part is connected to the electricity introducing body. A ceramic discharge lamp characterized in that it is supported by a fixed support member.