JPH0350609Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a high-pressure mercury lamp, and more specifically, to a high-pressure mercury lamp for large currents,
This invention relates to a high-pressure mercury lamp characterized by its hermetic sealing structure.

[Conventional technology]

In general, mercury lamps are widely used in fields that utilize ultraviolet rays emitted from them, such as the photochemical industry, semiconductor device manufacturing, and other fields.

For example, in high-pressure or ultra-high-pressure mercury lamps for large currents, the amount of mercury that is the main component of the luminescent gas is large, so the gas pressure inside the bulb when lit is very high, and the amount of heat generated is large, so it is particularly dangerous. The glass of the sealing part is required to have high heat resistance and pressure resistance. It is necessary that the mercury in the enclosure be completely evaporated during lighting, and therefore it is necessary that there be no low temperature areas where mercury would condense within the enclosure during lighting.

For this reason, conventional high-pressure or ultra-high-pressure mercury lamps do not use the so-called rod seal structure, in which the glass that forms the bulb's enclosure is directly welded to the power supply lead rod for an airtight seal. A so-called foil seal structure using metal foil is adopted.

Specifically, in the peripheral wall 16A of the glass bottomed cylinder 1A as shown in FIGS. 5 and 6, the seventh
As shown in Figures to Figure 9, for example, four band-shaped metal foils 2A are arranged so as to be spaced apart from each other in the circumferential direction and extend in the axial direction of the bottomed cylinder 1A, and these metal foils 2A
A holding plate 31A is formed at the base end of an internal lead rod 3A, which is arranged such that one end side 21A of each of the rods is bent at the bottom wall edge 11A of the bottomed cylinder body 1A and extends so as to protrude from the outside of the bottom wall 15A. The outer periphery of the external lead rod 4A is connected to the outer periphery of the external lead rod 4A, which is connected to the other end side 22A of each of the metal foils 2A at the open end edge 13A of the bottomed cylinder 1A, and is inserted into the cylindrical hole of the bottomed cylinder 1A. The electrically conductive part 5A for sealing is configured by connecting to the electrically conductive part 5A. 10A is a glass cylinder for holding the external lead rod 4A inserted into the bottomed cylinder 1A, 6A is an electrode fixed to the tip of the internal lead rod 3A, 7A
is a glass cylinder for holding the internal lead rod 3A.

Next, such a conductive part 5A for sealing is placed in the first
As shown in FIG.
Insert and arrange it so that it is located within 2. Then, heat treatment is performed from the outside of the sealed tube portion 81A to make the sealed tube portion 81
The inner periphery of A and the outer periphery of the bottomed cylinder 1A are airtightly welded via the metal foil 2A. and internal lead rod 3
On the proximal end side of A, the glass in the portion of the sealed tube section 81A facing the glass cylinder 7A is heated and pressed, or a negative pressure is applied inside the sealed tube section 81A, and this negative pressure is used to close the glass tube. The metal foil 2A is welded to the body 7A to form a narrowed portion 91A as shown in FIG. Cover the exposed parts with glass. In the other sealed tube portion 81A, a sealing conductive portion 5B having the same structure as the sealing conductive portion 5A is connected in the same manner as described above, thereby constructing a high-pressure mercury lamp as shown in FIG. 11.

[Problem that the invention attempts to solve]

However, the high-pressure mercury lamp having the above configuration is likely to suffer from the following problems.

(1) In the process of connecting the conductive parts 5A and 5B for sealing, when welding the inner peripheries of the sealed tube parts 81A and 81B and the outer peripheries of the bottomed cylinders 1A and 1B via the metal foils 2A and 2B, The glass of the sealed tube portions 81A, 81B is heated from the outside and pressed from the outside with a relatively strong force, or the glass of the sealed tube portions 81A, 81B is heated.
Negative pressure is applied inside 81B, and this negative pressure causes the outer end surfaces 12 of the bottom walls of the bottomed cylinders 1A and 1B to
It is necessary to crush the space facing A and 12B. Therefore, as shown in an enlarged view in FIG. 4 (only one sealed tube portion 81A is shown). Bottom wall outer end surface 12 of the bottomed cylinder 1A
The sealed tube portion 81A is sharply bent outside A to form a bent portion 83a with a small radius of curvature, and distortion is likely to occur in this portion. During lighting, the bottom wall 1 of the bottomed cylindrical body 1A
5A communicates with the light emitting space and becomes quite high temperature, and the pressure inside the enclosure 8 is extremely high, for example, 20 atmospheres or more.
There is a problem in that cracks are likely to occur due to the strain generated in a, and in the worst case, the high-pressure mercury lamp may explode, leading to a dangerous accident.

(2) On the bottom wall 15A side of the bottomed cylindrical body 1A, it is impossible to suddenly bend the sealed tube portion 81A with a small radius of curvature according to the outer shape extending from the peripheral wall 16A to the bottom wall 15A of the bottomed cylindrical body 1A. It is difficult to seal the outer circumferential surface of the bottomed cylinder 1A and the inner wall surface of the sealing tube portion 81A in a sufficiently tight state, and a large gap S is likely to occur between the two. Therefore, the bottom wall outer end surface 12 of the bottomed cylinder 1A
The contact area between A and the sealed gas in the sealing body 8 increases, and the pressure acting on the outer end surface 12A of the bottom wall increases, and the mechanical strength of the sealed portion of the sealed tube portion 81A against the internal pressure becomes insufficient. Sometimes.
Another problem is that the mercury in the enclosure 8 tends to condense within the space S.

[Purpose of invention]

The present invention was developed based on the above-mentioned background, and its purpose is to suppress the occurrence of distortion in the glass part of the sealed tube, and to have excellent heat resistance and pressure resistance, thereby preventing explosion accidents. An object of the present invention is to provide a high-pressure mercury lamp that can prevent the occurrence of oxidation and can be safely lit for a long time.

[Means for solving problems]

The high-pressure mercury lamp of the present invention includes a glass enclosure consisting of a light-emitting space surrounding part and a sealed tube part following this, and inside the sealed tube part of this enclosure, the open end is on the outer end side of the sealed tube part. a bottomed cylinder made of glass arranged so as to face toward the bottom, an external lead rod inserted into the cylindrical hole of the bottomed cylinder, and an external lead rod extending from the outside of the bottom wall of the bottomed cylinder into the light emitting space surrounding section. the arranged internal lead rod; an electrode provided at the tip of the internal lead rod; an electrode or filament provided at the tip of the internal lead rod; a conductive holding plate disposed facing the outer end surface of the bottom wall of the cylinder; and an electrically conductive holding plate extending along the outer periphery of the bottomed cylinder, one end of which is electrically connected to the holding plate, and the other end thereof being electrically connected to the holding plate. a plurality of band-shaped metal foils electrically connected to the external lead rod, the bottomed cylinder has a tapered outer peripheral surface in a peripheral wall portion that continues to the outer end surface of the bottom wall, and , the metal foil has an arc-shaped recess that fits the outer periphery of the internal lead rod at the end thereof connected to the holding plate, and the metal foil the foil is connected to the retaining plate;
The tips of adjacent metal foils are characterized in that they do not overlap each other and are in close contact with each other at part of their outer edges.

According to this structure, the outer circumferential surface of the circumferential wall portion following the outer end surface of the bottom wall of the bottomed cylinder is formed into a tapered shape, and the bottom portion is configured in the shape of a frustum of a cone, for example, a frustum of a cone. It is possible to reliably seal the sealed tube part of the sealed tube part along the peripheral wall of the bottomed cylindrical body in a state with little distortion without giving undue deformation, and in addition, the sealed tube part of the sealed body and the bottom of the bottomed cylindrical body There is no large gap between the seal and the wall, so the mechanical strength of the sealed portion is excellent.

In addition, an arc-shaped recess that matches the shape of the outer periphery of the internal lead rod is formed at the tip of the metal foil on the side that is connected to the holding plate, and when this arc-shaped recess is in contact with the outer periphery of the internal lead rod, The metal foil is connected to the holding plate by means such as welding, and the tips of adjacent metal foils do not overlap each other, but are in close contact with each other at a part of the outer edge of the tips, and welded to the plate. By connecting adjacent metal foils by such means as above, and by keeping adjacent metal foils in close contact with each other without overlapping each other, the contact area between the metal foil and the holding plate can be increased, and therefore the holding plate Even if the diameter is small, the connection between the two can be made sufficient.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

In one embodiment of the present invention, as shown in FIGS. 1 and 2, a bottomed cylinder 1A made of quartz glass is used.
is the peripheral wall 16A of the portion continuing from the bottom wall outer end surface 12A.
Tapered outer peripheral surface (hereinafter referred to as “tapered portion”)
It has a T-shaped bottom and a so-called mortar-shaped bottom. A disk-shaped holding plate 31A having a diameter that is approximately the same as the diameter of the bottom wall outer end face 12A is arranged on the bottom wall outer end face 12A of the bottomed cylinder 1A. A lead rod 3A is fixedly provided so as to extend in the axial direction of the enclosure 8 toward the light emitting space surrounding portion 82, and a cylindrical electrode 6A is provided at the tip of the internal lead rod 3A.

Further, on the outer periphery of the bottomed cylinder 1A, for example, four band-shaped molybdenum metal foils 2A are arranged so as to be spaced apart from each other in the circumferential direction and extend in the axial direction of the bottomed cylinder 1A. One end side 21A of each of the lead rods 2A extends along the tapered portion T of the peripheral wall 16A of the bottomed cylinder 1A, and is further attached to a retaining plate 31A formed at the base end of the internal lead rod 3A by means such as spot welding. It is connected. As shown in FIG. 3, at the tip of each one end side 21A of the metal foil 2A, a cutout-shaped arcuate recess C having a radius of curvature that is approximately the same as the radius of curvature of the outer peripheral surface of the internal lead rod 3A is formed. Then, the metal foil 2A is welded to the surface of the holding plate 31A on the side opposite to the inner lead rod 3A, with the arcuate recess C in contact with the outer peripheral surface of the inner lead rod 3A. By doing this, compared to the case where the tip of the metal foil 2A has a straight line as shown by the dashed line in FIG.
The contact area between the holding plate 31A and the holding plate 31A can be increased, so that the holding plate 31A can be replaced with the bottomed cylinder 1A.
Since it is possible to increase the welding area between the metal foil 2A and the retaining plate 31A by making it relatively small in diameter to correspond to the outer end surface 12A of the bottom wall, it is possible to sufficiently increase the mechanical strength of the welded part. can. At the tip of the one end side 21A of the metal foil 2A, both sides of the arcuate recess C are cut off to form a shoulder S, so that the tips of the adjacent metal foils 2A do not overlap each other and the shoulder S at the tip is cut off. They are brought into close contact with each other at a part of the outer edge.

Further, the other end side 22A of each of the metal foils 2A is bent at the open end edge 13A of the bottomed cylinder 1A, and is further held in the glass cylinder 10A inserted into the cylindrical hole of the bottomed cylinder 1A. External lead rod 4A
is connected to the outer periphery of the conductive part 5A for sealing.

Then, by heat-treating the bottomed cylinder 1A constituting the sealing conductive part 5A from the outside of the sealed tube part 81A of the enclosure 8, for example, the outer periphery of the bottomed cylinder 1A and the inside of the sealed tube part 81A are heated. The periphery is hermetically welded via the metal foil 2A, and furthermore, on the proximal end side of the internal lead rod 3A, the glass in the portion of the sealed tube portion 81A facing the glass cylinder 7A is heated and pressed or sealed. The narrowed portion 9A is formed by applying a negative pressure inside the tube portion 81A and welding it to the glass cylinder 7A using this negative pressure. Although not shown in the drawings, in the other sealed tube portion 81B, a conductive part for sealing configured in the same manner as the conductive part for sealing 5A is connected in the same manner as described above to form the sealed body 8.

The angle of the slope of the tapered portion T of the peripheral wall 16A of the bottomed cylinder 1A may be such that the opening angle α formed by the ridge line of the truncated cone is 15 to 120 degrees, as shown in FIG. Further, the projected length l in the axial direction of the tapered portion T of the peripheral wall 16A of the bottomed cylinder 1A may be about 1/2 to 1/15 of the total length L of the bottomed cylinder 1A.
Furthermore, the diameter of the bottom wall outer end surface 12A of the bottomed cylindrical body 1A is appropriately selected depending on the outer diameter of the sealed tube portion 81A of the enclosure 8, etc., but it is usually about 8 to 15 mm.

The holding plate 31A has a shape that almost matches the shape of the bottom wall outer end surface 12A of the bottomed cylinder 1A, and its diameter d is ±2 mm of the diameter D of the bottom wall outer end surface 12A of the bottomed cylinder 1A. In addition, the diameter d is at least 1 mm larger than the diameter of the internal lead rod 3A to ensure a sufficient welding area (welding allowance) with the metal foil 2A.
It is preferable to set it to a certain degree, and usually,
It is considered to be 0.5 to 20 mm.

Further, the method of connecting the retaining plate 31A and the internal lead rod 3A is not particularly limited, but the retaining plate 31A and the internal lead rod 3A may be butt welded, or a hole may be formed in the center of the retaining plate 31A, and the A method may be used in which the base end of the internal lead rod 3A is inserted into the inner lead rod 3A and the two are welded. The holding plate 3
Materials for constructing 1A include tantalum,
Refractory metals such as niobium, tungsten, and molybdenum can be used.

In other respects, the structure is substantially the same as that of the conventional high-pressure mercury lamp described above, so the same members are given the same reference numerals and detailed explanation thereof will be omitted.

According to the above embodiment, the bottom wall 1 of the bottomed cylinder 1A
Since the circumferential wall 16A continuing to 5A is configured in a tapered shape, when sealing the sealing body 8, the sealing tube portion 81A can be reliably moved along the circumferential wall 16A of the bottomed cylinder 1A without being unduly deformed. Therefore, it is possible to suppress the occurrence of distortion that may cause cracks in the deformed glass portion based on the sealing of the sealed tube portion 81A, and therefore, the occurrence of distortion that may cause cracks can be suppressed. The lights can be turned on safely without causing an extremely dangerous accident such as an explosion.

Further, the sealed pipe portion 81A is connected to the peripheral wall 1 of the bottomed cylinder 1A.
Since both can be sealed in close contact without causing excessive deformation along 6A,
There is almost no gap between the outer periphery of the bottomed cylinder 1A, the metal foil 2A, and the sealing tube portion 81A of the sealing body 8, and the three can be sealed in close contact with each other. The mechanical strength at the attachment part is excellent, and the sealing body 8 can have sufficient pressure resistance against internal pressure.

Further, an arc-shaped recess C that matches the shape of the outer periphery of the internal lead rod 3A is formed at the tip of the metal foil 2A on the side connected to the holding plate 31A, and this arc-shaped recess C forms the outer periphery of the inner lead rod 3A. The metal foils 2A are connected to the holding plate 31A in a state in which the metal foils 2A are in contact with the holding plate 31A, and the tips of the adjacent metal foils 2A are brought into close contact with each other at a part of the outer edge of the tips without overlapping each other. Therefore, the metal foil 2A and the holding plate 31
Therefore, even if the holding plate 31A has a small diameter, the connection between the two can be made sufficient, and as a result, the tapered portion T can be formed in the bottomed cylinder 1A. A sufficiently large electrical capacity can be easily achieved while forming a .

Furthermore, as mentioned above, because the tips of the adjacent metal foils 2A are in close contact with each other without overlapping each other, the outer periphery of the bottomed cylinder 1A, the metal foil 2A and the sealing body 8 in the sealing portion are Since there is no large gap between the sealed tube parts 81A, the metal foil 2
The heat generated at A is efficiently transmitted to the surrounding glass members, so that the metal foil 2A is not locally heated, and the metal foil 2A can be prevented from melting.

Further, on the surface of the holding plate 31A, a large gap is formed because the tips of adjacent metal foils do not overlap each other and are in close contact with each other at a part of the outer edge of the tips. Therefore, mercury in the enclosure 8 does not enter and condense.

Although one embodiment of the present invention has been described above, various modifications can be made to the present invention. That is, (1) By using the bottomed cylinder 1A whose inner diameter is slightly larger than the diameter of the external lead rod 4A, it is not necessary to use the glass cylinder 10A.

(2) The number of metal foils 2A and 2B is not limited to four, but may be two, three, or five or more.

(3) The external shape of the bottomed cylinders 1A and 1B is not limited to a cylindrical shape, but may be appropriately selected depending on the number of metal foils 2A and 2B used, and may be, for example, an octagonal prism, a square prism, a hexagonal prism, or other shapes. .

[Effect of idea]

According to the present invention, by using a bottomed cylinder having a tapered outer circumferential surface, it is possible to suppress the occurrence of distortion in the glass part of the sealed tube part, and it has excellent heat resistance and pressure resistance. To provide a high-pressure mercury lamp that can prevent the occurrence of an explosion accident, can therefore be safely lit for a long time, and can easily achieve a large-capacity electrical connection between a metal foil and an internal lead rod. can do.

[Brief explanation of drawings]

FIG. 1 is an explanatory longitudinal sectional front view showing a bottomed cylinder according to an embodiment of the present invention, FIG. FIG. 3 is an explanatory longitudinal sectional front view showing an enlarged view of the main parts of the present invention, FIG. 4 is an explanatory longitudinal sectional front view showing an enlarged main part of a conventional high-pressure mercury lamp, and FIGS. , respectively, are a side view and a front view showing a conventional bottomed cylindrical body, and FIGS. 7, 8, and 9 are an explanatory front view and an explanatory vertical right side view, respectively, showing a conductive part for sealing of a conventional high-pressure mercury lamp. FIG. 10 is a longitudinal sectional left side view for illustration and explanation, and FIG. 10 is a longitudinal sectional front view for illustration showing a state in which the conductive part for sealing of a conventional high-pressure mercury lamp is arranged in a sealed tube section. FIG. 11 is an illustration showing a conventional high-pressure mercury lamp. FIG. 1A, 1B...Bottomed cylindrical body, 15A...Bottom wall, 1
6A... Peripheral wall, T... Tapered portion, 12A... Outer end surface of bottom wall, 2A, 2B... Metal foil, C... Arc-shaped recess, 3A, 3B... Internal lead rod, 31A... Holding plate, 4A, 4B...External lead rod, 5A, 5B
... Conductive part for sealing, 6A, 6B ... Electrode, 7A,
7B...Glass tube, 8...Envelope, 81A, 8
1B... Sealed tube section, 82... Light emitting space surrounding section, 9
A, 9B... Constricted portion, 10A, 10B... Glass cylinder.

Claims (1)

[Claims for Utility Model Registration] A glass enclosure consisting of a light emitting space surrounding section and a sealed tube section following it, where the open end of the enclosed tube section is located within the sealed tube section and the outer end of the sealed tube section. a bottomed cylinder made of glass arranged to face the side; an external lead rod inserted into the cylindrical hole of the bottomed cylinder; and an external lead rod extending from the outside of the bottom wall of the bottomed cylinder into the light emitting space surrounding section. an internal lead rod arranged as shown in FIG. and a plurality of conductive holding plates extending along the outer periphery of the bottomed cylindrical body, one end of which is electrically connected to the holding plate, and the other end electrically connected to the external lead rod. a strip-shaped metal foil, the bottomed cylinder has a tapered outer peripheral surface in a peripheral wall portion that continues to the outer end surface of the bottom wall, and the metal foil has a side connected to a retaining plate. has an arc-shaped recess that fits the outer circumference of the internal lead rod at the tip thereof, and the metal foil is connected to the holding plate with the arc-shaped recess in contact with the outer peripheral surface of the internal lead rod,
A high-pressure mercury lamp characterized in that the tips of adjacent metal foils do not overlap each other but are in close contact with each other at part of their outer edges.