JPH05174710A - Method of forming single-sealed lamp - Google Patents

Abstract

PURPOSE:To decrease the number of times of heating or air cooling and prevent occurrence of residual stress or distortion by performing sealing of the end of a glass tube softened by heating and the molding the glass tube into a sphere or an ellipsoid by blow at the same time or sequentially. CONSTITUTION:The top of an exhaust pipe 11 is opposed to the end of a quartz glass tube 10, and one end of the tube 10 is heated by a gas burner 20 for junction. By this heating, one end of the tube 10 softens, and accompanying this softening, the surface tension occurs in the glass, and the tube 10 shrinks and its diameter thins. By the reduction of diameter, one end of the tube 10 is welded to the end of the exhaust pipe 11, whereby the tube 10 and the exhaust pipe 11 are junctioned together. The other end of the tube 10 is opened, and this opening is sealed by a mount 15. That is, the tube 10 is heated by a hydrogen burner for heating so as to soften the whole, and then the opening of the tube 10 is pressed, whereby it becomes a sealed part being shut off air- tightly, and at the same time, a metallic foil conductor 4 of a mount 15 is sealed on the sealed part.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a bulb of a discharge lamp or an incandescent lamp in which a crushed seal portion is formed only at one end.

[0002]

2. Description of the Related Art Recently, small discharge lamps and incandescent lamps, especially halogen incandescent lamps are used in combination with a reflecting mirror to restrict the irradiation light, and it is often applied to, for example, floodlighting devices and spot downlights. It's coming. In such a case, the light source is required to be small and highly efficient because it is mounted on a reflecting mirror.

To miniaturize a discharge lamp or a halogen lamp,
It is advantageous to use a valve in which the sealing part is formed only at one end. That is, when the sealing portion is formed at both ends of the valve, not only is the sealing process troublesome, but the sealing portion has a large heat releasing action, so the amount of heat released from both ends increases.
There are problems such as a decrease in lamp efficiency. Therefore, it is desirable to provide the sealing portion only at one end of the bulb.

In addition, in the case of incandescent light bulbs such as halogen light bulbs, if an infrared reflection visible light transmission film is formed on the inner surface or the outer surface of the bulb, the infrared reflection visible light transmission film emits light emitted from the filament. Of these, the infrared region is reflected and returned to the filament, so that the filament is heated again by the reflected infrared rays. Therefore, the heat loss emitted from the lamp is reduced, the lamp efficiency is increased, the power consumption is reduced, and the luminous efficiency is improved. For this reason, it is advantageous to form an infrared reflection visible light transmitting film on the inner surface or the outer surface of the bulb.

In such a halogen light bulb, if the bulb is shaped as a sphere or an ellipse, the infrared rays reflected by the infrared reflecting visible light transmitting film are effectively reflected at the center of the bulb or the focal position of the ellipse. As a result, the infrared rays are surely returned to the filament, the infrared absorption efficiency of the filament is increased, and the luminous efficiency is improved.

By the way, in order to obtain the above-mentioned spherical or elliptic spherical bulb shape, it is necessary to blow a glass tube made of quartz or the like to inflate it.

Therefore, this type of lamp requires a blow molding and a sealing step of crushing and sealing one end. In each of these operations, the quartz glass is heated and softened and then molded by a molding die or pincher. It is necessary to process it.

[0008]

However, in the conventional case, an exhaust pipe made of a thin tube is melt-connected in advance to one end of a tube made of quartz glass to form stepped tubes having different diameters, and this tube is heated. This tube is softened and surrounded by a mold, and in this state, a gas such as air or an inert gas is blown into the valve from the exhaust pipe to blow mold the tube, thereby molding the tube into a sphere or an ellipsoid. Was there. Further, after this blow molding, a filament mount is inserted into the bulb through the other end opening of the tube, the opening end is softened by heating, and this portion is crushed and sealed by a pincher.

Such a molding method has an exhaust pipe connecting step,
The blow molding step and the crushing and sealing step are performed, but all of these steps are operations of heating, heating and softening the glass material to be the exhaust pipe and the valve, and then performing connection, molding, and sealing. In the conventional case, since the steps are independent of each other, the glass material is repeatedly heated and softened and air-cooled and solidified in each step.

However, for example, during blow molding, it is difficult to heat and soften only the blown portion, so it is unavoidable to heat up to the planned sealing portion that is not processed in this step. For this reason, there is a problem in that the portion which is later heat-softened and processed is affected by the heat of the previous step, the shape is collapsed, stress and strain remain, and the mechanical strength of the product is lowered. Further, there is a problem that silica is deposited between a softened portion and a non-softened portion of the glass and the silica must be removed later, which is troublesome.

The present invention has been made in view of such circumstances, and an object thereof is to avoid repeated heating and softening and air-cooling and solidifying of a glass tube in each step, and to avoid undesired deformation and Another object of the present invention is to provide a method for molding a single-sealed lamp that can prevent the generation of residual stress and strain and the reduction in mechanical strength.

[0012]

In order to achieve the above object, the present invention achieves the above object by crushing one end opening of a heat-softened glass tube and sealing a mount having a discharge electrode or filament at this end. Simultaneously with or after such a sealing step, when the tube is in a softened state, a gas is blown from the other end opening of the tube to blow-mold the tube to form a sphere or an elliptical sphere. Characterize.

[0013]

According to the above method, at least the crushing and sealing step of the opening end and the blow molding step are performed continuously, so heating and softening is required only once in these steps, and therefore, unwanted deformation and residual Generation of stress and strain and reduction of mechanical strength are reduced.

Further, since the sealing step and the blow molding step are immediately and continuously performed, these steps can be continuously performed at the same position in the manufacturing apparatus, and the workability is improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIGS. This embodiment shows an example applied to a single-sealed halogen light bulb, and FIG. 4 shows a sectional view of the completed halogen light bulb, which will be described below.

In the figure, reference numeral 1 is a quartz glass valve, and this valve 1 has a spherical shape with an outer diameter of about 8 to 15 mm, and one end thereof has a chip-off remaining by cutting off an exhaust pipe. The part 2 is formed and the other end is crushed and sealed.

A pair of metal foil conductors 4 and 4 made of molybdenum or the like are sealed in the crushing and sealing portion 3, and internal lead-in wires 5 and 5 are connected to the metal foil conductors 4 and 4.
These internal lead wires 5 and 5 are introduced into the bulb 1, and a filament 6 made of a tungsten coil is provided between both ends thereof.
Has been erected. External lead-in wires 7 and 7 are connected to the pair of metal foil conductors 4 and 4 sealed to the sealing portion 3. Argon gas having a predetermined pressure and halogen such as a bromine compound are enclosed in the valve 1.

An infrared-reflecting visible light transmitting film 8 is formed on the outer or inner surface of the bulb 1. The infrared reflection visible light transmission film 8 is a light interference film, and it is known, and therefore, it is not shown in the drawing, but it is formed as a multilayer film in which high refractive index layers and low refractive index layers are alternately laminated, for example, 9 to 17 layers in total. However, it has a property of reflecting infrared rays, but transmitting visible light.
The high refractive index layer is made of titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), zirconium oxide (ZrO ₂ ), zinc sulfide (ZnS), and the low refractive index layer is silicon oxide (silica = SiO _2). ), Magnesium fluoride (Mg
F ₂ ) and the like.

In the halogen bulb having such a structure, when the filament 6 is energized to emit light, this light is transmitted through the bulb 1, and this light is transmitted through the infrared reflection visible light transmission film 8 formed on the outer surface of the bulb 1. When reaching, the light in the infrared region of, for example, 700 to 1300 nm in this light is reflected by the infrared reflection visible light transmission film 8 and mainly visible light is transmitted. The reflected infrared rays are returned to the filament 6,
Therefore, the filament 6 is heated again by the reflected infrared rays. Therefore, the heat emitted from the lamp is reduced, the lamp efficiency is increased, the power consumption is reduced, and the luminous efficiency is improved. Next, a method of manufacturing a halogen light bulb having such a configuration will be described with reference to FIGS.

FIG. 1 shows the process of joining the exhaust pipes. In FIG. 1A, reference numeral 10 is a quartz glass tube serving as a valve, for example, outer diameter 8 mm, inner diameter 6 mm, length 20.
It is formed to about mm. Reference numeral 11 is an exhaust pipe made of a quartz glass tube having an outer diameter of 4 mm, an inner diameter of 2.2 mm and a length of 7
It is formed to about 0 mm. Reference numeral 15 is a mount, and a pair of external introduction wires 7, 7 are integrally connected in a U-shape.

To mold the bulb 1, as shown in FIG. 1B, the tip of the exhaust pipe 11 is attached to the quartz glass tube 1.
The quartz glass tube 10 is opposed to the end portion of 0 and one end of the quartz glass tube 10 is heated by the bonding gas burner 20. Due to this heating, one end of the quartz glass tube 10 is softened, the surface tension is generated in the glass due to this softening, and the diameter of the quartz glass tube 10 is reduced and the diameter is reduced.

Due to such a diameter reduction, one end of the quartz glass tube 10 is welded to the end portion of the exhaust pipe 11, so that the quartz glass tube 10 and the exhaust pipe 11 are integrated as shown in FIG. 1 (C). To be joined to. The other end of the quartz glass tube 10 is opened, and the mount is sealed in this opening. This sealing step will be described with reference to FIG.

That is, in FIG. 2A, the quartz glass tube 10 having the exhaust pipe 11 joined to one end is heated by the heating oxyhydrogen burner 22 to soften the whole. In this case, if the tube 10 is rotated around the axis, uniform heating is performed.

The tube 10 thus softened
As shown in FIG. 2 (B), the mold is housed in a molding die 25, and a pincher 28 as a crushing sealing jig faces the opening at the other end.

Although not shown in detail, the molding die 25 is formed by a split mold which can be split in the right and left directions or in the direction orthogonal to the paper surface, and when abutting against each other, a spherical molding surface 26 is formed on the inner surface. Is becoming

In this case, the main body of the mold 25 is made of a heat resistant metal such as stainless steel,
The molding surface 26 of this embodiment is made of ceramics having a lower thermal conductivity than that of the main body portion and excellent heat resistance and wear resistance, for example, SiC, Si ₃ N ₄ , TiC, TiN, ZrO ₂ or the like. ..

The pincher 28 is separated from the molding die 25 and is operated independently. And
Although not shown in detail, the pincher 28 is also formed by a pair of pinchers that can be divided in a direction orthogonal to the paper surface, and the pinchers 28 press the end portion of the glass tube 10 to crush and seal it.

In this case, the main body of the pincher is also formed of a heat resistant metal such as stainless steel, but the pressing surface 29 in contact with the glass tube 10 has a lower thermal conductivity than that of the main body, and the heat resistance and wear resistance are high. Ceramics with excellent properties such as SiC, Si ₃ N ₄ , TiC, Ti
It is composed of N, ZrO ₂ , and the like.

When the molding surface 26 and the pressing surface 29 are made of ceramics, they do not easily react with SiO ₂ forming the glass tube 10, have excellent oxidation resistance and wear resistance, have high hardness and little wear, and are separated from each other. Since no mold agent is required and the surface condition is kept good for a long period of time, the surface condition of the glass tube 10 can be finished neatly, and unevenness and cracks are prevented from occurring to improve the molding efficiency.

A mount 15 is inserted from the other end opening into the softened glass tube 10 surrounded by the molding die 25 and the pincher 28, and the filament 6 is positioned and held at a predetermined position of the glass tube 10. ..

In this state, the pair of pinchers are moved in the direction orthogonal to the paper surface to press the other end opening of the glass tube 10. As a result, the opening of the other end of the glass tube 10 in the softened state is crushed as shown in FIG. 2 (C), which is hermetically closed to form the sealing portion 3 and the sealing portion. Mounted on 3 and metal foil conductors 4 and 4 of 15
Is sealed. This completes the sealing process, but when the glass tube 10 is still in the softened state, the blow molding is continued.

That is, in FIG. 3A, pressurized air or a pressurized inert gas such as nitrogen is blown into the tube 10 from the exhaust pipe 11 connected to one end of the quartz glass tube 10. Then, the softened tube 1
0 is bulged because the internal pressure is high, and a spherical molding surface 26 formed on the molding die 25 surrounding the tube 10.
Pressed against. Therefore, the spherical valve 1 is obtained by such blow molding.

After the blow molding as described above is completed, the tube 10 is removed from the molding die 25 after the tube 10 is cooled and solidified, and a pair which is integrally connected in a U-shape as shown in FIG. 3B. The external introduction lines 7, 7 are cut and separated. Also,
The inside of the valve 1 is evacuated using an exhaust pipe 11 joined to one end of the valve 1, and a halogen such as an argon and bromine compound is enclosed in the valve 1. Then, as shown in FIG. 3B, the root of the exhaust pipe 11 is a sealing bar.
The exhaust pipe 11 is sealed and cut by being heated and softened by the nozzle 23. As a result, the valve 1 is closed as shown in FIG. Then, an infrared reflecting visible light transmitting film 8 is formed on the outer surface of the bulb 1 to complete the halogen bulb shown in FIG.

According to the molding method of this embodiment, after the glass tube 10 is heated and softened, the crushing and sealing step of the open end shown in FIG. 2 and the blow molding step shown in FIG. Since the heat treatment of the tube 10 is performed only once in these two steps because it is performed, undesired deformation, residual stress and residual strain do not occur in the valve 1, and it is possible to improve the mechanical strength against impact or the like. ..

The sealing step and blow molding step are as follows.
Since the glass tube 10 can be immediately and continuously performed in the softened state, these steps can be continuously performed at the same position in the manufacturing apparatus, and simplification of the apparatus and improvement of workability can be expected.

It should be noted that it is not impossible to simultaneously perform the above-mentioned sealing step and blow molding step, or to perform the blow molding step first and then immediately perform the sealing step while the glass tube 10 is softened. In the blowing step, since the pressurized gas is blown to inflate the tube, it is necessary to close the other end of the tube. Considering this point, it is preferable to seal the tube first. However, the mold 25
The glass tube 10 may be surrounded by the timing after the crushing and sealing by the pincher 28 is completed. The present invention is not limited to the above embodiment.

That is, in the above-mentioned embodiment, the case where the thin tube exhaust pipe 11 is connected to the glass tube 10 in advance to form the valve has been described, but when the special exhaust pipe 11 as described above is used, FIG. An exhaust pipe connecting step as shown is required, and in this case, the glass tube 10 needs to be heated and cooled once. On the other hand, a molding method in which the exhaust pipe is not used will be described based on the second embodiment shown in FIGS. 5 and 6.

In FIG. 5, the glass tube 30 shown in FIG. 5A has an outer diameter of 8 mm and an inner diameter of 6 which does not have a special exhaust pipe.
It is a straight type glass tube of about mm and is heated by the heating oxyhydrogen burner 22 to soften the whole. Also in this case, if the tube 10 is rotated around the axis, uniform heating is performed. As shown in FIG. 5B, the tube 30 in the softened state is formed into the molding die 2
5, and the pincher 28 is opposed to the opening at the other end.

The molding die 25 of the present embodiment has a pressing portion 27 for drawing at the upper end portion integrally or separately, and a pressing surface made of ceramics is also formed on the inner surface of the pressing portion 27. There is.

When the molding die 25 is abutted to surround the glass tube 30, the pressing surface 27 presses the glass tube 30 to reduce its diameter, and the small-diameter throttle portion 31 is formed there. There is.

Such a molding die 25 and pincher 2
The mount 15 is inserted into the opening of the other end of the glass tube 30 in the softened state surrounded by 8, and the filament 6 is positioned at a predetermined position of the glass tube 30, and the pincher 2
The other end opening of the glass tube 30 is pressed by 8.
As a result, the other end opening of the glass tube 30 in the softened state is crushed as shown in FIG. 5 (C), and this is hermetically closed to form the sealing portion 3. The metal foil conductors 4 and 4 of the mount 15 are sealed to the sealing portion 3. This completes the sealing process, and when the glass tube 30 is still in the softened state, the blow molding is started.

As shown in FIG. 6 (A), blow molding is carried out from one end of the quartz glass tube 30 to the tube 30.
A pressurized inert gas such as nitrogen is blown into the inside. Then, the softened tube 30 swells and is pressed against the molding surface 26 of the molding die 25. Therefore, the spherical valve 1 is obtained by such blow molding.

After the blow molding as described above is completed, the tube 30 is removed from the molding die 25 after it is cooled and solidified, and the pair is integrally connected in a U-shape as shown in FIG. 6B. The external introduction lines 7, 7 are cut and separated. Also,
The inside of the valve 1 is exhausted from one end of the valve 1 and the valve 1
Halogen such as argon and bromine compounds are enclosed therein. Then, the small-diameter throttle portion 31 formed at one end of the valve 1 is heated and softened by the sealing burner 23 as shown in FIG. As a result, the valve 1 is closed as shown in FIG.
After that, the infrared reflecting visible light transmitting film 8 is formed on the outer surface of the bulb 1 to complete the halogen bulb shown in FIG. 5 as in the first embodiment.

In the case of this embodiment, since no special exhaust pipe is used, no special work is required for connecting the exhaust pipe 11, and the number of times the glass tube 30 is heated and softened is reduced, so that deformation or Residual stress and residual strain are not generated, and the mechanical strength is improved.

In this case, the glass tube 30 may be surrounded by the molding die 25 after the end sealing portion 3 is molded. In this case, the small-diameter throttle portion 31 is crushed and sealed. It will be formed later.

In the case of the second embodiment, the molding die 2 is used.
5, the pressing portion 27 for the diaphragm is formed, and the glass tube 30 is pressed by this pressing surface to reduce the diameter to form the small-diameter drawing portion 31, but such a small-diameter drawing portion 31 is not specially made. Alternatively, the straight tube end may be directly cut off.

That is, the glass tube has a property that the softened portion is reduced in diameter by surface tension when it is softened by heating, let alone a glass tube having an outer diameter of 8 mm and an inner diameter of 6 mm as described above, which is directly caused by the diameter reduction. It is possible to cut off the seal, which is advantageous in that the labor of previously providing the exhaust pipe 11 and the small-diameter throttle portion 31 can be saved.

In each of the above-mentioned embodiments, the halogen bulb in which the filament 6 is arranged in the direction orthogonal to the bulb axis has been described, but the filament may be oriented along the bulb axis. Furthermore, the infrared reflective visible light transparent film may be formed on the inner surface of the bulb 1, or may be a lamp without the infrared reflective visible light transparent film.

Further, in the above embodiment, the case of the single-sealed halogen light bulb has been described, but the present invention is applicable to a small discharge lamp such as the single-sealed metal halide lamp shown in FIG. It is feasible.

In the single-sealed metal halide lamp shown in FIG. 7, 51 is a bulb, 52 is a chip-off portion, and 53.
Is a crushed seal portion, 54 and 54 are metal foil conductors, 55 and 55 are electrodes, 56 and 56 are electrode shafts, 57 and 57 are electrode coils,
Reference numerals 58 and 58 are external lead wires. It is also effective to apply the molding method of the present invention to a single-sealed metal halide lamp having such a structure.

Further, in the above embodiment, the glass tube 10 was heated and softened in advance, and the mount 15 provided with the discharge electrode or the filament was inserted from the opening at one end of the tube to seal the opening end. , The mount 15 provided with the discharge electrode or filament is previously inserted from one end opening of the glass tube 10, and the tube 10
May be softened by heating to seal the opening end.

[0052]

As described above, according to the present invention, the end of the heat-softened glass tube is sealed and the blow molding into a sphere or an elliptical sphere is performed simultaneously or successively, so that the glass tube is The number of times of heating and air cooling is reduced, and it is possible to prevent undesired deformation of the valve, occurrence of residual stress and strain, and deterioration of mechanical strength.

Further, since the sealing step and the blow molding step are immediately and continuously performed, these steps can be continuously performed at the same position in the manufacturing apparatus, and the workability is improved.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a first embodiment of the present invention and illustrating a process of joining exhaust pipes.

FIG. 2 is a diagram illustrating a sealing process of the example.

FIG. 3 is a diagram illustrating a blow molding process of the example.

FIG. 4 is a cross-sectional view showing a completed halogen light bulb of the embodiment.

FIG. 5 is a diagram illustrating a sealing process according to the second embodiment of the present invention.

FIG. 6 is a diagram illustrating a blow molding process of the example.

FIG. 7 is a sectional view of a discharge lamp showing a third embodiment of the present invention.

[Explanation of Codes] 1 ... Bulb, 2 ... Chip off part, 3 ... Sealing part, 6 ... Filament, 8 ... Infrared reflection visible light transmitting film, 10, 30 ...
Quartz glass tube, 11 ... Exhaust pipe, 12 ... Open end,
15 ... Mount, 25 ... Blow mold, 26 ... Molding surface,
31 ... A small-diameter throttle section.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Kawakatsu 1-48 Mita, Minato-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (3)

[Claims] 1. A heat-softened glass tube is crushed at one end to seal a mount having a discharge electrode or a filament at this end, and the tube is brought into a softened state during or after the sealing. A method for molding a single-sealed lamp, characterized in that a gas is blown from the other end opening of the tube at a certain time to blow-mold the tube into a spherical or elliptical spherical shape. 2. An exhaust pipe is connected to the other end of the glass tube in advance, and a gas is blown into the tube through the exhaust pipe during the blow molding. Molding method for single-sided lamp. 3. The lamp is an incandescent lamp in which a filament is housed inside a bulb, and the bulb has an infrared reflection visible light transmitting film for returning infrared rays to the filament on an inner surface or an outer surface thereof. 7. A method for molding a single-sealed lamp according to claim 1.