JPH11144680A - Bulb sealing body and bulb - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bulb being less broken at a weld sealing end of a tube in a sealing process of an electric discharge lamp or an incandescent electric bulb or the like and in an assembling and fabricating process following the sealing process and a bulb using it. SOLUTION: This bulb sealing body 4 for sealing a tube 3 continuously provided at a light emitting tube 2 of a bulb, consists of a substantially columnar tilt function material formed of a conductive part 41 and an insulation part 40, and forms a groove part on an outer periphery successively to an outer end of a weld sealed part. Alternatively, a step is provided on the outer periphery so that an outer diameter of a part from the outer end of the welded sealing part outwardly is smaller than the outer diameter of the weld sealed part. Further, this sealing body 4 is used for a bulb.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closing member for a bulb made of a functionally graded material for closing a closing tube portion of a discharge lamp such as a mercury lamp, a xenon lamp or a metal halide lamp, or an incandescent lamp such as a halogen lamp or a halogen heater. , And a tube using the tube closure.

[0002]

2. Description of the Related Art Recently, a functionally graded material has begun to be used as a closure for sealing a closure tube connected to an arc tube of a discharge lamp in which a pair of electrodes are arranged opposite to each other within an arc tube made of silica glass. . The closure formed of the functionally graded material,
One side is rich in an insulating inorganic material component such as silica, and the ratio of a conductive inorganic material component such as molybdenum increases continuously or stepwise toward the other side. Therefore, for example, in the case of a plug using a functionally gradient material composed of silica and molybdenum, one side of the plug is insulative and has a coefficient of thermal expansion equal to or the same as the coefficient of thermal expansion of the silica glass of the arc tube material. The other side is electrically conductive and has a characteristic that the coefficient of thermal expansion is close to the coefficient of thermal expansion of tungsten or molybdenum which is the material of the electrode rod. This property is suitable as a tube blockage.

[0003] In the incandescent lamp such as a halogen lamp or a halogen heater having a filament heating element, the arc tube is made of silica glass, so that the functionally gradient material can be used as a closing body.

FIG. 1 is a sectional view showing an example of a conventional discharge lamp using a functionally graded material as a closing body of the discharge lamp.
The arc tube 2 and the closed tube 3 of the discharge lamp 1 are made of an insulating inorganic material component (for example, silica glass), and a pair of electrodes 5 and 5 facing each other are arranged inside the arc tube 2. The two electrodes are located at the tip of the electrode rod 6, and the electrode rod 6 is inserted up to the conductive portion 41 of the closing body 4 and shrink-fitted.
Reference numeral 7 denotes an external lead, which is shrink-fitted like the electrode core rod. In some cases, the external lead 7 and the electrode core 6 may be integrated and shrink-fitted through the closing body 4.

The closing member 4 is cylindrical, has a uniform outer diameter in the axial direction, and is formed of an insulating inorganic material component (eg, silica) and a conductive inorganic material component (eg, molybdenum). One side (the inner side of the arc tube) of the closing body 4 is an insulating portion 40 rich in an insulating inorganic material component, and the other side (the outer side of the arc tube) is a conductive portion 4 rich in a conductive inorganic material component.
It is one. Then, the end face of the insulating inorganic substance component side is arranged so as to face the discharge space of the arc tube 2 of the discharge lamp 1,
The closed tubes 3 formed at both ends of the arc tube 2 are hermetically welded and sealed at the insulating portion 40 of the closed body 4.

When an obstruction made of a functionally graded material is used as an obstruction for a tube, conventionally, as shown in FIG. The closure 4 made of a functional material is made to protrude from the closure tube 3 so that the conductive portion 41 of the closure 4 is directly sandwiched between the band-shaped bases 10 to supply power (protruding closure). However, in order to prevent breakage of the closing body, recently, as shown in FIG. 2, the closing pipe has a role of a “protection pipe” that extends the closing pipe 3 and is longer than the closing body 4 to protect the closing body. Let's add this to the base 10
Is fixed by an adhesive 17 (protective tube type). In the discharge lamp having the structure of FIG. 2, the external lead rod 7 protruding from the end face of the conductive part of the closing body 4 is welded to the external lead rod extension line 9 and the welding portion 8,
The external lead rod extension 9 is brazed at a brazing portion 11 of a base 10.

[0007] In the above-mentioned "closing body protruding type" system, when the inside of the arc tube 2 is kept at a negative pressure, the insulating property of the closing body 4 in the closing tube 3 is set in the welding and sealing at the insulating portion 40 of the closing body 4. By heating the portion where the portion 40 is located from outside of the closed pipe with a flame burner, the closed pipe 3 is melted and deformed so as to reduce the diameter, and the closed pipe 3 and the insulating portion 40 of the closed body 4 are airtightly sealed. Weld to.

In the latter "protective tube type" system, when a cylindrical closing member 4 having a constant outer diameter in the axial direction is used, the inner wall of the closing tube 3 and the insulating portion 40 of the closing member 4 are brought into close contact with each other. In the process of welding and sealing, the glass separates from the functionally graded material closure at a sharp angle, as shown in FIG. 3, at the point where the joining is just separated, that is, at the outer end of the welded portion of the closure. Further, the outer edge of the welded joint surface was wavy, and it was difficult to control the shape.

That is, in the "protective tube type" system,
The outer end of the welded portion is an edge portion 12, and the edge portion 12 is a structural singularity that is weak against stress. When welding and sealing, a force is applied to the discharge lamp and stress concentration occurs on the edge portion 12. Easy to happen. And finally the edge part 1
The trouble that the closing body 4 is broken at 2 occurs.

Further, when assembling and manufacturing a discharge lamp having a “protective tube type” configuration, an external lead rod extension 9 is welded to an external lead rod 7 protruding from a functionally graded material closing member 4.
For example, when the extension lamp 9 is inserted into the base 10 by spot welding or the like, a force is applied to the discharge lamp, and the discharge lamp may be broken at the edge portion 12 which is a singular point.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a process for sealing a bulb such as a discharge lamp or an incandescent lamp and a process of assembling and sealing a closed tube with a closed body in an assembly and manufacturing process after the sealing process. An object of the present invention is to provide an occluder for a tube which is less likely to be broken and broken at an end portion, and a tube using the same.

[0012]

In order to solve the above-mentioned problems, the invention according to claim 1 is a tube closing member for sealing a closing tube connected to an arc tube of a tube, A substantially columnar functionally graded material composed of a conductive inorganic material component and an insulating inorganic material component, in which the conductive portion and the insulating portion are formed by the gradient of the conductive inorganic material component concentration along the axial direction. And a groove is formed on the outer peripheral surface of the welded portion where the closed tube is welded and sealed, and a groove is formed on the outer peripheral surface of the closed portion.

Next, a second aspect of the present invention is a bulb closing member for sealing a closing tube connected to an arc tube of a bulb,
A substantially columnar functionally graded material composed of a conductive inorganic material component and an insulating inorganic material component, in which the conductive portion and the insulating portion are formed by the gradient of the conductive inorganic material component concentration along the axial direction. And a step is provided on the outer peripheral surface so that the outer diameter of a portion extending outward from the outer end of the welded portion to which the closed pipe is welded and sealed is smaller than the outer diameter of the welded sealed portion. A closed body for a tube characterized by the above.

Further, according to a third aspect of the present invention, there is provided a bulb having an arc tube, an obstruction tube connected to the arc tube, and an obstruction for obstructing the obstruction tube, wherein the obstruction is made of a conductive inorganic material. Component and an insulating inorganic material component, and is formed of a substantially columnar functionally graded material in which a conductive portion and an insulating portion are formed by a gradient of the conductive inorganic material component concentration along the axial direction. And a groove is formed on the outer peripheral surface continuously to the outer end of the portion to be welded in which the closing tube is welded and sealed, and the closing tube has a longer length than the welded and sealed portion of the closing body. It is a tube characterized by having.

According to a fourth aspect of the present invention, there is provided a bulb having an arc tube, an obstruction tube connected to the arc tube, and an obstruction for obstructing the obstruction tube, wherein the obstruction is made of a conductive inorganic material. Component and an insulating inorganic material component, and is formed of a substantially columnar functionally graded material in which a conductive portion and an insulating portion are formed by a gradient of the conductive inorganic material component concentration along the axial direction. And a step is provided on the outer peripheral surface so that the outer diameter of a portion extending from the outer end of the welded portion to which the closed pipe is welded and sealed is smaller than the outer diameter of the welded sealed portion. The closed tube has a length longer than a welded sealed portion of the closed body.

Further, the invention according to claim 5 is characterized in that the concentration of the conductive inorganic substance component at the outer end of the portion to be welded to which the closed tube is welded and sealed is 0% by volume or more and 3% by volume or less. The closing body according to claim 1 or claim 2.

[0017]

A groove is formed on the outer peripheral surface continuously from the outer end of the welded portion where the closing tube is welded and sealed, or a portion extending from the vicinity of the outer end of the welded portion where the closing tube is welded and sealed to the outside. When a closed body is provided with a step on the outer peripheral surface so that the outer diameter is smaller than the outer diameter of the welded portion, the sharpness of the edge angle of the edge formed at the outer end of the welded portion is reduced, so that the tube is The mechanical strength of the edge of the closing body against such stress increases, and the mechanical strength of the tube also increases.

[0018]

Embodiments of the present invention will now be described with reference to the drawings. The method for producing the functionally gradient material constituting the closing body of the present invention is roughly as follows. After preparing a plurality of types of mixed powders having different mixing ratios of the insulating inorganic material component powder and the conductive inorganic material component powder, mixing them with a solvent containing an organic binder, and granulating the insulating inorganic material component powder, A uniform composition layer is laminated for each mixing ratio with the conductive inorganic substance component powder and pressed to form a columnar molded body.

FIG. 9 shows a pressurizing method for molding the functionally graded material. On the upper surface of the bottom member 22 of the mold 20 having a cylindrical molding space, a mixture having the lowest concentration of the conductive inorganic substance component is placed. The powder is filled in layers, then the mixed powder having the second lowest concentration of the conductive inorganic substance is filled in layers, and the mixed powder having the conductive inorganic substance concentration changed in this order is required in the number of layers. Filling and then pressurizing with a pressurizing body 21 to form a formed layer laminate 23 in which a plurality of layers are integrally laminated. FIG. 9 shows a state of five layers. After that, temporary sintering for removing the organic binder is performed.

After provisional sintering, a hole for inserting an electrode core rod having substantially the same diameter as the electrode core rod from the surface of the end surface to the conductive portion of the closing body is provided substantially at the center of the insulating side end surface of the molded layer laminate 23. To process.

Next, in the present invention, the outer peripheral surface continuous to the outer end of the sealed portion to be welded of the closed body in which the closed tube is welded and sealed is cut by using a lathe to form a groove, or the same is used for closing with a lathe. Shaving the outer peripheral surface of the unsealed part of the body. After the electrode core rod is inserted into the hole for inserting the electrode core rod, main sintering is performed.

In the case of an incandescent lamp such as a halogen lamp shown in FIG. 11, the internal lead rod 16 is inserted into the hole of the closing body in place of the electrode core rod 6, and the main sintering is performed.

As another method of manufacturing the closing body of the present invention, for example, as shown in FIG. 10, the completed closing body has a shape (a shape in which the diameter of the non-welded portion of the closing body is smaller than the diameter of the portion to be welded). A uniform layer laminate in which a plurality of layers each having a uniform composition are integrally laminated may be formed using the mold 20 having the inner surface shape described above.

The completed closure is welded and sealed to the closure tube of the discharge lamp with a flame burner such as an oxyhydrogen burner.

[0025]

Next, an embodiment of the present invention will be described specifically. As the gradient functional material, silica (SiO ₂ ) was used as an insulating inorganic substance component, and molybdenum (Mo) was used as a conductive inorganic substance component. A molybdenum powder having an average particle size of 1.0 μm and a silica powder having an average particle size of 5.6 μm are prepared, a mixed powder having a different volume ratio of silica is prepared, and the mixed powder is mixed with stearic acid to granulate. 9 and laminated in the mold 20 shown in FIG. 9 in ascending order of volume ratio of silica, and compressed in the axial direction with a load of 1.5 t / cm ² by the pressurizing body 21 to obtain a cylindrical shaped layer laminate. 23 was obtained. Then, the molded layer laminate 23 was temporarily sintered in a hydrogen gas at 1200 ° C. for 30 minutes to remove the organic binder.

After the preliminary sintering, a hole for inserting an electrode core rod was formed on the silica-side end surface of the blocker made of a functionally graded material. Then, the outer peripheral surface continuous to the outer end of the sealed portion to be welded of the closing body was cut and grooved using a lathe. The dimensions of the functionally-graded material closing body are such that the overall length in the axial direction is 12 mm and the outer diameter in the radial direction is 2.1.
mm. The appropriate depth of the groove is 0.1 to 0.5 mm, and in the present embodiment, it is 0.2 to 0.3 mm. The position of the grooved portion was 5 mm from the silica-side end face. If the molybdenum concentration of the functionally graded material is too high, the closed body will crack when sealed with the closed tube, so the groove position depends on the molybdenum concentration distribution in the axial direction determined when designing the functionally graded material. I do.

Next, a tungsten electrode rod was inserted into a hole for inserting the electrode rod, and heated at 1820 ° C. for 5 minutes in a vacuum atmosphere to perform a final sintering process of shrink-fitting the electrode rod.

When the obstruction body made of a functionally graded material is welded to the obstruction pipe, it is welded at the insulating portion of the obstruction body. Conventionally, a region in which the molybdenum concentration of the functionally gradient material is 0% to 1.7% by volume% is regarded as a region that can be welded and sealed to the closed tube. However, as a result of diligent research by the inventors, the molybdenum concentration of the functionally graded material is 1% by volume.
It was confirmed that up to a region of more than 7% and up to 3%, the closed body could be welded to the closed tube without cracking. That is, the closed body can be sealed in the closed tube in the range of the molybdenum concentration of 0 to 3 wt%, the width of the sealed region can be made relatively wide, and more airtight sealing can be performed.

FIG. 2 is a cross-sectional view of a discharge lamp in which a conventionally used columnar closing member made of a functionally graded material is used for sealing a closing tube, and the closing tube is longer than a sealed portion to be welded of the closing member. The figure shows that the outer diameter A of the portion to be welded and sealed is equal to the outer diameter B of the portion that is not welded and sealed (A = B). On the other hand, FIGS. 4 to 8 and 11 are partial sectional views showing an embodiment in which the tube closing member of the present invention is applied to a discharge lamp. C in FIG. 6 is the outer diameter of the groove. In the example of FIG.
B, A = B and A> C in the example of FIG. 6, and A>B> C in the example of FIG. In the example of FIG. 8, the tapered portion 14 is formed on the side of the closed body facing the light emitting space, and the gas withstand pressure in the light emitting tube is increased. The tapered portion was formed by turning the closing body on a lathe and cutting the blade with a carbide tool obliquely from the closing body. FIG. 11 shows an example in which the closing body of the present invention is used for a halogen lamp as an incandescent lamp.

Next, an obstruction made of a functionally graded material of the present invention, a discharge lamp as a bulb using the obstruction of the present invention, a conventional obstruction made of a columnar functionally graded material and a discharge using the obstruction The result of examining the damage ratio when the lamp is actually manufactured will be described. The discharge lamp using the closed body of the present invention has the shape shown in FIG. 4, and the discharge lamp using the conventional closed body has the shape shown in FIG.

The dimensions of the closure used in the manufactured discharge lamp are as follows. [Conventional product] Overall length: 12 mm Outer diameter: 2.1 mm [Product of the present invention] Overall length: 12 mm Outer diameter of welded and sealed portion: 2.1 mm Outer diameter of unwelded portion: 1.8 mm Groove depth: 0 .2mm groove width: 1mm

The prepared plugs were 50 conventional products and 100 products of the present invention. For comparison, a discharge lamp was manufactured using each of the plugs. When the conventional closing member is used as the closing member of the discharge lamp, in the step of welding and sealing the closing member and the closing tube, ten closing members of 50 discharge lamps are edged at the outer end of the sealed portion to be welded. Breaked and damaged. Further, among the 40 lamps remaining during the welding and sealing step, 5 lamps were damaged during the manufacture of the lamp assembly for attaching the base.
That is, 15 out of 50 pieces were damaged.

On the other hand, when the plug of the present invention was used as a plug of a discharge lamp, in the process of welding and sealing the plug and the plug tube, the plug in 100 discharge lamps was broken and damaged. It was a book, and only one of the lamps was damaged during the manufacture of the lamp assembly for attaching the base. That is, only one of the 100 pieces was damaged. As described above, since the groove is formed on the outer peripheral surface continuously to the outer end of the sealed portion to be welded, the tube is obviously broken and broken at the closed tube portion in the sealing step of the bulb and the assembling and manufacturing process after the sealing step. It can be seen that a tube with less trouble can be obtained.

As shown in FIG. 6, the present invention has a groove 13 on the outer peripheral surface which is continuous with the edge 12 which is the outer end of the portion to be welded.
4, or as shown in FIG. 4, a small-diameter portion is formed from the edge portion 12, which is the outer end of the welded portion, to the conductive portion 41. Therefore, as shown in FIG. This is due to the fact that the angle (θ) formed by the outer surface of the closing body becomes large, and there is no sharp edge as in the conventional FIG.

In the above description of the embodiment, the description has been made of the closure made of a functionally gradient material composed of a combination of silica and molybdenum. However, as the insulating inorganic substance component, alumina, zirconia, magnesia, silicon carbide, silicon nitride, titanium carbide , Etc. can be used as practical materials, and nickel, tungsten, tantalum, chromium, platinum, etc. can be used as practical materials as the conductive inorganic substance component.

The shape of the closing body is not limited to a columnar shape, but may be a prism having a polygonal cross section perpendicular to the axis. However, in the case of a polygonal prism, not the outer diameter, but the maximum dimension of the cross section is smaller at the portion that is not sealed by welding than at the portion to be sealed.

[0037]

As described in detail above, the sharpness of the angle of the edge of the outer end of the welded sealing portion of the closed tube portion is reduced by using the tube closing member according to the first aspect of the present invention. The lamp bulb can be prevented from being broken and broken during the manufacturing process of the lamp.

With the use of the tube closing member according to the second aspect of the present invention, since the outside diameter of the portion of the closing member that is not welded is small, it does not come into contact with the inside diameter of the closed tube, and the tube is more resistant to breakage. .

In the tube according to the third aspect of the present invention, since the closing body forms the groove on the outer peripheral surface continuous with the outer end of the sealed portion to be welded, the sharpness of the angle of the edge of the sealed portion to be welded is sharp. And the mechanical strength of the edge portion is increased, so that the edge is hardly broken. In addition, since the obstruction tube covers the entire obstruction, it functions sufficiently as a protective tube.

In the bulb according to the fourth aspect of the present invention, the outer diameter of the portion of the closed body in which the closed pipe is welded and sealed from the outer end of the welded portion is smaller than the outer diameter of the welded sealed portion. Since the outer peripheral surface is stepped as described above, the sharpness of the angle of the edge portion of the sealed portion to be welded is eliminated, and the mechanical strength of the edge portion increases, so that it is difficult to break, and the closing pipe also covers the entire closing body Therefore, it functions well as a protection tube.

According to the fifth aspect of the present invention, the obstruction body made of a functionally graded material can be sealed in the obstruction pipe within the range of the molybdenum concentration of 0 to 3 wt%, and the welding sealing area can be widened. Even more airtight sealing can be achieved.

[Brief description of the drawings]

FIG. 1 shows a partial cross-sectional view of an example of a conventional discharge lamp using a functionally graded material as a closing body of the discharge lamp.

FIG. 2 is a partial cross-sectional view of a discharge lamp using a conventional functionally graded material closure.

FIG. 3 is an enlarged view of an edge part of a partial cross-sectional view of the discharge lamp shown in FIG. 2;

FIG. 4 shows a partial cross-sectional view of an embodiment in which the closure made of a functionally gradient material according to the present invention is applied to a discharge lamp.

5 is an enlarged view of an edge portion of the partial cross-sectional view of the discharge lamp shown in FIG.

FIG. 6 is a partial cross-sectional view of another embodiment of a closure made of a functionally graded material and a discharge lamp using the same according to the present invention.

FIG. 7 is a partial cross-sectional view of another embodiment of a closure made of a functionally gradient material and a discharge lamp using the same according to the present invention.

FIG. 8 is a partial cross-sectional view of another embodiment of a closure made of a functionally gradient material and a discharge lamp using the same according to the present invention.

FIG. 9 shows a diagram of a general pressurizing method when molding an obstruction made of a functionally gradient material.

FIG. 10 shows a diagram of a pressurizing method as an example when forming the closed body made of a functionally graded material of the present invention.

FIG. 11 is a cross-sectional view of a functionally graded material closure according to the present invention and an incandescent lamp using the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Discharge lamp 2 Arc tube 3 Closed tube 4 Closed body 5 Electrode 6 Electrode core rod 7 External lead rod 8 Welding part 9 External lead rod extension line 10 Base 11 Brazing part 12 Edge part 13 Groove part 14 Taper part 15 Filament 16 Internal lead Rod 17 Adhesive material 20 Mold 21 Pressing body 22 Bottom member 23 Molded layer laminate 40 Insulating part 41 Conductive part A Outside diameter of welded and sealed part of closure B Outside of non-welded part of closure Diameter C Outer diameter of groove of closed body

Claims (5)

[Claims] 1. A tube closing body for sealing a closing tube connected to an arc tube of a tube, comprising a conductive inorganic material component and an insulating inorganic material component, and conductive along an axial direction. Is formed of a substantially columnar functionally graded material in which a conductive portion and an insulating portion are formed by gradiently changing the concentration of a conductive inorganic substance component, and the outside of the welded portion where the closed tube is welded and sealed. A closed body for a tube, wherein a groove is formed on an outer peripheral surface continuously from an end. 2. A closed body for a bulb for sealing a closed tube connected to an arc tube of a bulb, comprising a conductive inorganic material component and an insulating inorganic material component, and electrically conductive along an axial direction. Is formed of a substantially columnar functionally graded material in which a conductive portion and an insulating portion are formed by gradiently changing the concentration of a conductive inorganic substance component, and the outside of the welded portion where the closed tube is welded and sealed. A tube closing body characterized in that a step is provided on an outer peripheral surface so that an outer diameter of a portion from an end to an outer side is smaller than an outer diameter of a portion to be welded. 3. A bulb having an arc tube, an obstruction tube connected to the arc tube, and an obstruction for obstructing the obstruction tube, wherein the obstruction comprises a conductive inorganic material component and an insulating inorganic material component. The conductive tube is made of a substantially columnar functionally graded material in which a conductive portion and an insulating portion are formed by gradiently changing the concentration of the conductive inorganic substance component along the axial direction, and the closed tube is welded. A groove is formed on the outer peripheral surface continuously to the outer end of the welded portion to be sealed, and the closing pipe has a length longer than the welded sealing portion of the closing body. Tube. 4. A bulb having an arc tube, an obstruction tube connected to the arc tube, and an obstruction for obstructing the obstruction tube, wherein the obstruction comprises a conductive inorganic material component and an insulating inorganic material component. The conductive tube is made of a substantially columnar functionally graded material in which a conductive portion and an insulating portion are formed by gradiently changing the concentration of the conductive inorganic substance component along the axial direction, and the closed tube is welded. A step is formed on the outer peripheral surface so that the outer diameter of a portion from the outer end of the welded portion to be sealed to the outside is smaller than the outer diameter of the welded portion, and the closed pipe is sealed by welding the closed body. A tube having a length longer than a stop portion. 5. The method according to claim 1, wherein the concentration of the conductive inorganic substance component at the outer end of the portion to be welded to which the closed tube is welded and sealed is 0% by volume or more and 3% by volume or less. The closure as described.