JPH0454338B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a short arc type ultra-high pressure discharge lamp equipped with a straight tube-shaped bulb made of translucent ceramic.

[Conventional technology]

2. Description of the Related Art Hitherto, as shown in Japanese Patent Laid-Open No. 58-81454, a high-intensity short-arc ultra-high-pressure discharge lamp equipped with a straight tube-shaped bulb made of sapphire is known. The device shown in this publication is made of Saphire and has a straight tube type valve with metallization applied to both ends, and the caps with electrodes supported at both ends are sealed via metal joint tubes such as Kovar. , Attach an exhaust pipe to one base, and
A ceramic ring is interposed between the valve and the cap, and a heat shield formed on the ring covers the brazed portion between the valve and the joint pipe from the inside.

In a short arc ultra-high pressure discharge lamp with such a configuration, by providing a ceramic tube body,
In addition to increasing the reliability of brazing between the valve and the joint pipe, thermal insulation between the valve and the fitting is achieved, and the heat shielding effect of the heat shielding part of the ceramic ring makes it possible to braze the valve and the joint pipe. This suppresses the temperature rise in the area.

[Problem that the invention seeks to solve]

As described above, the conventional structure in which a heat-insulating ring body is interposed between the valve and the fitting in addition to the joint pipe that connects them has the problem of a large number of parts. If this is omitted, not only will the reliability of the brazing between the valve and the joint pipe be degraded, but the brazed part will be exposed to high temperatures, making it difficult to use under harsh thermal conditions. Not only is it not suitable for
A problem arises in that the temperature of the cap increases. As described above, in the conventional structure using the ceramic annular body, the permissible temperature for use depends on the heat resistance of the brazed part, and the use is usually limited to 400 degrees Celsius or less.

By the way, in order to maintain the performance of the brazed part, the valve diameter may be increased or air cooling may be applied from the outside. However, increasing the bulb diameter not only impairs the downsizing, which is one of the characteristics of using translucent sapphire bulbs, but also prevents the inside of the bulb from being used at angles other than the limited usage angle. This is not a desirable countermeasure because the convection of the filled gas becomes easy, causing the arc to flicker or break out. In addition, when applying air cooling from the outside, air cooling equipment is required, it is difficult to apply to lamp houses where air cooling is not possible, and the direction in which cooling air is blown is determined. As a result, the valve is cooled unevenly.
This was not a desirable countermeasure because it promoted convection of the filled gas and caused the arc to flicker or break out. Moreover, the conventional configuration requires metallization of the valve and troublesome brazing work, which, as mentioned above, has the problem of high manufacturing costs due to the large number of parts.

An object of the present invention is to obtain a short-arc type ultra-high-pressure discharge lamp that has a simple structure, is suitable for use under harsh conditions where air cooling is not possible, and is of high quality, has a long life, and is inexpensive. .

[Means for solving problems]

In order to achieve the above object, the present invention provides a pair of left and right members connecting a straight tube-shaped bulb made of translucent ceramic and a base supporting an electrode.
Using ceramic base tubes having approximately the same coefficient of thermal expansion as the above-mentioned valve, the fitting stepped portion formed at one end of these base tubes is directly fitted to the end of the above-mentioned valve, and there is a gap between them. The base tube and the end of the base are bonded via a provided glass solder material, and an anode and a cathode disposed in the base are provided concentrically on the central axis of the base tube. It is something that

[Effect]

In the present invention, the end portion of the translucent ceramic bulb and the fitting stepped portion of the ceramic base tube body are directly fitted, and the fitting surfaces are bonded with a glass solder material. Therefore, the heat resistance of this sealing part can be greatly improved. because,
Since the glass solder material is melted by high-temperature heating between the mating surfaces and then solidified to bond the bulb and the base tube, it has heat resistance up to close to its melting temperature. Since the base pipe connecting the bulb and the cap is made of ceramic, its low thermal conductivity makes it possible to achieve thermal insulation between the bulb and the cap. This not only eliminates the need for the conventional ceramic ring, but also allows use under harsh conditions without requiring external air cooling. Moreover, since the base tube is made of ceramic, there is no need to perform troublesome metallization on both ends of the valve connected to it, and the valve and base tube can be bonded together by heating in a high-temperature furnace. Since a large number of valves can be manufactured at the same time and is highly suitable for mass production, and the length of the valve can be shortened by using a ceramic base tube, the number of parts can be reduced as described above, and the valve can be obtained at low cost. Furthermore, as mentioned above, since the base tube is made of ceramic, impurities in the sealed gas will not be released from the base tube when the temperature of the tube increases during use. Moreover, since machining of this ceramic base tube is easy unlike glass material, it is possible to provide the fitting stepped portion with high precision.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is a straight pipe type valve with both ends open.
It is made of translucent ceramic such as sapphire or translucent alumina. One ends of base tubes 2 and 3 having the same outer diameter as the valve 1 are connected to both ends of the valve 1, respectively, as will be described later. The pair of left and right base tubes 2 and 3 are each made of ceramic such as alumina, which has substantially the same coefficient of thermal expansion as the bulb 1.

Fitting step portions 2a and 3a are formed at one end of the base tubes 2 and 3 on the valve side, respectively.
a, 3a are directly fitted to the ends of the bulb 1, and the bulb 1 and the base tube bodies 2, 3 are bonded to each other through a glass solder material (not shown) provided between these fitting surfaces. This bonding is done by the crystal solder method to the valve 1 and the base tubes 2 and 3.
A glass solder material is attached in advance to at least one of the fitting steps 2a and 3a, and then these are fitted together and heated to a high temperature in a heating furnace to melt the glass solder material and form a bond on the fitting surface. This is carried out by spreading the melted glass solder material over the entire surface and then solidifying the molten glass solder material.

A cap 4 is attached to the other end of one base tubular body 2 so as to close the opening, and a cap 5 is attached to the other end of the other base tubular body 3 so as to close the opening. These caps 4 and 5 are made of a metal material such as iron or Kovar. Note that 6 in the figure is a copper washer. Further, a joint tube 7 made of a metal material such as iron or Kovar is fitted over the base 4 and the base tube side end portion of the base tube body 2.

An anode 8 is supported on one base 4. This anode 8 connects a tungsten anode head 9 disposed within the bulb 1 and an anode rod 10 provided through the base 4 through a partition 11 within one base tube 2. It is formed by This anode 8 is arranged concentrically on the center line of the base tube body 2. Anode 8
Getter 1 made of zirconium etc. is on the outer periphery of the
2 is wrapped around it. The anode rod 10 is made of tungsten, molybdenum, etc., and includes a terminal plate 1.
6 is installed.

Further, the other base 5 supports a cathode 13 which is disposed close to and opposite to the anode 8 within the bulb 1 . The cathode 13 is made of triudet tungsten or the like, and in this embodiment, it is connected to the tip of an exhaust pipe 14 provided through the base 5 via a partition 15. Supported. This cathode 13 is arranged concentrically on the center line of the base tubular body 3. The exhaust pipe 14 is made of a metal material such as nickel, and 14a and 15a in the figure indicate vent holes, respectively. Then, through this exhaust pipe 14, a sealed gas containing an appropriate metal vapor in an inert gas such as xenon gas is introduced into the internal space defined by the valve 1, the base pipes 2 and 3, and the caps 4 and 5. is sealed under a predetermined pressure.

Each of the partitions 11 and 15 is made of an electron tube material such as nickel, and in this embodiment also serves as a joint member as described above. These partitions 11 and 15 have a gap area between them and the base tubes 2 and 3 in which they are arranged.
The gap area is smaller than that of other parts of 3.
Note that the partition 11 is connected to the anode head 9 and the anode rod 1.
These partitions 11 and 15 do not have to serve as a joint structure, and a ring-shaped partition may be fitted to the outer periphery of the anode 8 or the exhaust pipe 14. , or may be provided by fitting into the base tubes 2 and 3.

The short-arc xenon lamp described above is constructed by fitting the ends of the light-transmitting ceramic bulb 1 and the ceramic base tubes 2 and 3, which have substantially the same coefficient of thermal expansion, and applying glass solder to the fitting surfaces. Because of the bonded structure, this sealing part has heat resistance close to the melting temperature of the glass solder material. Furthermore, since the melting temperature of the glass solder material is extremely high compared to that of metal solder, the heat resistance of the sealing part can be greatly improved, for example, heat resistance up to 800 degrees can be obtained. Furthermore, since the ceramic base tubes 2 and 3 are used instead of metal tubes to connect the valve 1 and the caps 4 and 5, their low thermal conductivity provides thermal insulation between the bulb 1 and the caps 4 and 5. can be achieved.

That is, as described above, the valve 1 and the caps 4, 5
Ceramic and base pipe body 2 are used to connect the
By using 3, heat resistance is greatly improved and thermal insulation is possible, which makes it possible to eliminate the need for heat shielding parts that were conventionally necessary to protect the sealing part from heat. Therefore, it can be used even under severe conditions without requiring external air cooling, and its versatility can be significantly improved. Of course, due to the above-mentioned significant improvement in heat resistance, the diameter of the valve 1 etc. can be reduced, and convection of the filled gas is suppressed even when used at angles other than the limited usage angle, reducing the occurrence of flickering etc. can be prevented.

Moreover, since the base tubes 2 and 3 are made of ceramic, there is no need to perform troublesome metallization on both ends of the light-transmitting ceramic bulb 1 connected thereto, and the bulb 1 and the base tube 2, Bonding with No. 3 can be carried out simultaneously by heating in a high-temperature furnace, and since it is highly mass-producible, it can be obtained at low cost by reducing the number of parts mentioned above.

Of course, as mentioned above, the valve 1 and the base pipe body 2,
Since the heat resistance of the sealing parts with 3 is high, it is possible to shorten the length of the bulb 1 by bringing these sealing parts closer to the light emitting point between the electrodes. It is possible to reduce costs by reducing the amount of light-transmitting ceramic bulb 1 used. In addition, the ceramic base tubes 2 and 3 are manufactured by heating and sintering at high temperatures and do not contain any impurities, so when the lamp reaches high temperatures in the early stages of use, it will adversely affect the lamp life. Does not release impurities. Therefore, this lamp can be used for a long period of time. Further, since the base tubes 2 and 3 are made of ceramic, fitting step portions 2a and 3a for connection with the valve 1 can be provided at the ends thereof by machining. Therefore, the fitting step portion 2a,
The dimensional accuracy of 3a can be improved. and,
Anode 8 and cathode 13 for base tubes 2 and 3
Since the electrodes 8 and 13 are each supported concentrically, the electrodes 8 and 13 can be assembled with the bulb 1 as a reference. That is, since the fitting stepped portions 2a and 3a of the base tubes 2 and 3 are fitted and connected to the ends of the valve 1, the center lines of the base tubes 2 and 3 are aligned with respect to the valve 1 by these fittings. The position of can be determined.
The positioning accuracy of the valve 1 and the fitting steps 2a, 3
Although it depends on the accuracy of fitting with a, since the dimensional accuracy of the fitting steps 2a and 3a is high as described above, by using the valve 1 as a reference, both base tubes 2 and 3
can match the center lines of, and therefore,
Misalignment of the axes of the anode 8 and cathode 13, which are concentrically supported by these, is prevented, and a high-quality lamp can be obtained.

Moreover, since the partition 11 is provided, the convection of the filled gas in the direction of the base 2 supporting the anode 8 can be suppressed by the damming action of the partition 11 in both vertical lighting and horizontal lighting. This makes it possible to reduce the temperature rise of the base 2 supporting the anode 8 and maintain it at a low temperature, which is advantageous when the base 2 is connected to a socket.

Note that the present invention relates to a short arc type ultra-high pressure mercury lamp,
It can be applied to short arc ultra-high pressure metal hydride lamps, etc., and the exhaust pipe can be installed in the base tube instead of the cap.

〔Effect of the invention〕

As explained above, according to the present invention, the member that connects the translucent ceramic bulb and the cap is a ceramic base tube, which is directly fitted onto the bulb and bonded with a glass solder material. As a result, the heat resistance of the sealing part can be greatly improved, allowing a simpler structure by omitting the need for a member to protect the sealing part from heat, and making it suitable for use under harsh conditions where air cooling is not possible. is also suitable, and
It is possible to omit the troublesome metallization process in the connection between the valve and the base pipe body, and it is suitable for mass production, so it is easy to manufacture, and in addition, the valve length can be shortened, so it can be obtained at low cost. In addition, impurities in the sealed gas are not released from the base tube body, which improves the lamp life and provides high quality with less deviation between the center lines of the electrodes.

[Brief explanation of the drawing]

The drawing is a longitudinal sectional side view showing a short arc xenon lamp according to an embodiment of the present invention. 1... Valve, 2, 3... Base pipe body, 2a,
3a... Fitting stepped portion, 4, 5... Base, 8... Anode, 13... Cathode, 11... Partition.

Claims (1)

[Scope of Claims] 1. A straight tube-shaped bulb made of translucent ceramic; and a bulb made of ceramic that has a coefficient of thermal expansion substantially equal to that of the bulb, and one end of which is directly fitted to the end of the bulb. A pair of left and right bases each having a fitting stepped portion and bonded to both ends of the bulb through a glass solder material provided between the stepped portion and the end portion of the bulb to be fitted thereto. a tube body; a pair of left and right caps each closing the other end opening of each of the base tubes; an anode provided on the base tube and supported by one of the pair of caps, and a tip portion provided concentrically on the center line of the other base tube and disposed within the bulb to the anode. A short arc type comprising a cathode supported by the other of the pair of caps in close opposition to each other, and a sealed gas sealed in an internal space surrounded by the valve, the base pipe body, and the pair of caps. Ultra-high pressure discharge lamp.