JP2003123646A - Manufacturing method of blocking body for sealing arc tube of discharge lamp, blocking body for sealing arc tube, and discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a blocking body for sealing the arc tube of a discharge lamp that is of high quality and high productivity. SOLUTION: The manufacturing method comprises a slurry preparation process in which a slurry 10 that corresponds to each layer of the blocking body made of a plurality of sinter layers is prepared by mixing tungsten powder, silica powder, organic binder, organic solvent, and dispersant, a formed body forming process in which a tungsten wire 5 is dipped in the slurry 10 with the axial center perpendicular and then pulled up and drying of the slurry 10 adhered to the tungsten wire 5 is repeated, and by laminating plural formed body layers, formed bodies 11 are manufactured, and a firing process in which the formed bodies 11 are fired and the blocking body is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closing body for sealing an arc tube of a discharge lamp, a method for manufacturing the same, and a discharge lamp provided with such a closing body.

[0002]

2. Description of the Related Art Discharge lamps, especially high pressure discharge lamps utilizing arc discharge, have high output and high brightness characteristics, but
The inside of the arc tube becomes high temperature and high pressure at the time of lighting. In order to prevent the luminescent substance inside the arc tube from leaking even under such high temperature and high pressure,
The high-pressure discharge lamp has conventionally adopted a method of sealing a metal foil on the end of the arc tube.

However, in this method, while the number of times of lighting is small, no particular problem occurs. However, when the number of times of lighting is increased, the sealing portion is cracked due to thermal stress caused by a difference in thermal expansion coefficient between the metal foil and the arc tube. There is a problem that occurs. The crack leaks the luminescent material inside the arc tube to the outside of the tube, which shortens the life of the lamp and significantly deteriorates the performance of the high pressure discharge lamp.

In order to solve the above-mentioned problem, Japanese Patent Laid-Open No. 5-290810 proposes a method of closing the end of the arc tube with a closing member. This closed body is obtained by providing a molded body having a structure in which a plurality of metal wires for electrode connection are concentrically stacked and firing the molded body. As for the constituent components of each layer, the component of the metal introduction line decreases as the component moves from the inner peripheral side to the outer peripheral side, and conversely, the component of the arc tube increases. Therefore, the closure has a structure in which the coefficient of thermal expansion thereof gradually changes from that of the metal lead-in wire to that of the arc tube. Therefore, even if the temperature inside the arc tube rises,
The thermal stress generated between the metal introducing wire and the arc tube can be gradually relaxed in the intermediate layer of the closing body, and the above-mentioned cracks can be prevented from occurring.

As a method for producing such a closed body, a slurry is prepared from a metal introduction wire corresponding to the constituent components of each layer and powder of each component of the arc tube, an organic binder, an organic solvent, a dispersant, etc., and the slurry is prepared. A method in which each layer is laminated by repeating coating and drying on the metal introduction line, a green sheet corresponding to each layer is produced from each slurry, and this green sheet is sequentially laminated on the metal introduction line. Then, a method of firing the produced molded body is described in the above publication.

[0006]

However, the method using the above-mentioned closure is a useful method which can prevent the occurrence of cracks, but has a problem that the quality and productivity of the closure are difficult. That is, in the former method of coating and drying the slurry on the metal introduction line and stacking the layers, the layer thickness changes depending on the slurry application amount and the application position, and each layer does not become concentric with respect to the metal introduction line. In terms of shape, it is difficult to obtain a closed body of constant quality.

On the other hand, in the latter method of laminating the green sheet on the metal lead-in wire, since the thickness-controlled green sheet is used, it is easy for the size and shape to become constant, and it is easy to obtain a product of constant quality. Since a green sheet is produced, the cost will increase compared to the former. In addition, it takes time and effort to match the winding start and the winding end of the green sheet wound around the metal lead-in wire with no overlap and a poor productivity.

The present invention has been made to solve the above problems, and is a method of manufacturing a closing body for sealing an arc tube of a discharge lamp, the size and shape of which are easy to control and the productivity of which is high. An object of the present invention is to provide a closed body for tube sealing and a discharge lamp.

[0009]

In order to achieve the above-mentioned object, a method for manufacturing an arc tube sealing closure of a discharge lamp according to the present invention comprises an outer circumference of a metal lead wire for supplying power to electrodes in the arc tube. In, a method of providing a molded body of a plurality of substantially concentric circularly laminated structure, to obtain a closed body by firing the molded body, a slurry preparation step of preparing a slurry for each layer of the molded body, A step of dipping the metal introduction wire into the slurry of the innermost layer, drying the adhered slurry, and then successively dipping, adhering and drying the slurry from the second layer to the slurry of the outermost layer. I am trying.

According to this method, since the metal introducing wire is dipped in the slurry, the slurry can be easily attached to the metal introducing wire and the productivity can be improved. For example, in the molded body manufacturing step,
The metal introduction line, in a state where its axis is vertical, is dipped into the slurry and pulled up, the slurry can be attached concentrically around the metal introduction line, and the thickness of each layer is further increased. A uniform molded body can be obtained, and a high-quality closed body can be easily obtained.

After the step of producing the molded body, a cutting step of cutting the molded body into a predetermined length while leaving the metal introduction line so that the metal introduction line is exposed from the molded body is characterized. Furthermore, the slurry preparation step includes a step of preparing a slurry containing an easily decomposable organic material, and the molded body preparation step includes a plurality of layers of the molded body,
Before laminating at least one layer, the step of dipping the metal introducing wire into a slurry containing the easily decomposable organic material and drying the attached slurry to laminate the organic material layer is included. In particular, the organic material layer is characterized by being laminated before laminating the innermost layer of the molded body,
The easily decomposable organic material is varnish. With this structure, the void layer remains in the organic material layer, and the plugging body can shrink in the radial direction when the temperature is lowered after firing, and cracking can be prevented.

The slurry for the layer near the metal introduction line of the molded body is a powder of the first metal material having a characteristic closer to the coefficient of thermal expansion of the metal introduction line than the coefficient of thermal expansion of the arc tube. Including, the slurry preparation step includes a step of preparing a slurry containing a powder of a second metal material having a melting point of the metal introduction line and a melting point of the first metal material lower than the melting point of the first metal material, Of the multiple layers of the molded body,
Before laminating at least one layer, the step of dipping the metal introducing wire into a slurry containing the powder of the second metal material, and drying the attached slurry to laminate the metal layer, It is characterized in that the molded body produced in the body producing step is fired at a temperature higher than the melting point of the second metal material and lower than the melting point of the metal introducing wire and the melting point of the first metal material. In particular, the metal layer is laminated before laminating the innermost layer of the molded body, and further, the second metal material is manganese. By doing so, manganese is melted during firing, and the inner and outer layers thereof can be firmly bonded by liquid phase sintering.

The slurry for the layer near the metal introduction line of the molded body is a powder of a third metal material having a characteristic closer to the coefficient of thermal expansion of the metal introduction line than the coefficient of thermal expansion of the arc tube. And including the step of preparing an alloy slurry containing at least one of the powder of the material of the metal introduction wire and the powder of the third metal material, and the powder of manganese, and the alumina powder. And a step of preparing an alumina slurry containing silica powder, wherein the step of producing the molded body includes at least one of a plurality of layers of the molded body.
Before laminating two layers, a step of dipping the metal introducing wire in the alloy slurry and drying the deposited alloy slurry to laminate the alloy layer, and the metal introducing wire in which the alloy layer is laminated, A step of dipping in an alumina slurry, drying the adhered alumina slurry to laminate an alumina layer, and a metal introduction wire in which the alumina layer is laminated,
The molded body produced in the molded body producing step includes a bonding layer forming step of dipping in the alloy slurry, drying the adhered alloy slurry, and laminating an alloy layer. Firing is performed at a temperature higher than the melting point of manganese and lower than the melting point of the metal introducing wire and the melting point of the third metal material in a hydrogen atmosphere adjusted to -5 ° C. In particular, the bonding layer forming step is performed before stacking the innermost layer of the molded body, and further, the material of the metal lead-in wire is tungsten or molybdenum. According to this structure, manganese in the inner and outer layers of the alumina layer is partially oxidized to become manganese monoxide, and a glass layer having high adhesion can be formed together with alumina and silica.

The powder of the third metallic material contains at least one of a powder of tungsten and a powder of molybdenum, and further, in the slurry preparing step, the content of manganese in the alloy slurry. 1 to
The content of silica in the alumina slurry is set to 30 wt%, and the content of silica is set to 1 to 5 wt%. This makes it possible to provide a suitable composition for exposing the glass layer during firing.

The arc tube sealing block manufactured by the above manufacturing method has high productivity, the thickness of each layer is uniform, and is substantially concentric with the metal introduction line. Further, in the discharge lamp in which the arc tube is sealed using the above-mentioned arc tube sealing block, since the thickness of each layer is uniform and the block that is substantially concentric with the metal introduction line is used, The pipe can be reliably sealed and the life can be extended.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a high pressure discharge lamp using a closing body according to the present invention will be described below with reference to the drawings. 1. First Embodiment 1-1. Structure of High-Pressure Discharge Lamp FIG. 1 is a schematic perspective view showing the structure of a high-pressure discharge lamp 1 using a closure according to the present invention, and is shown in a sectional view so that the internal structure can be seen. Since the high-pressure discharge lamp 1 in the present embodiment is bilaterally symmetrical, only one end (right side) is shown in the figure.

The high-pressure discharge lamp 1 includes a main tube 6 having a substantially spheroidal emission space 7 and side tubes 8 provided on both sides of the main tube 6, and a main tube 6 for emitting light. A pair of tungsten electrodes 3 arranged to face the space 7,
A molybdenum wire 5 for supplying power to the tungsten electrode 3 and a closing body 9 for closing the side tube 8 of the arc tube 2 are provided.

The arc tube 2 is made of quartz glass,
For example, a halogen substance such as iodine and bromine as well as a noble gas such as mercury, which is a light emitting substance, and a starting aid, such as argon, krypton, and xenon, are enclosed therein. The halogen substance evaporates from the tungsten electrode 3 by the halogen cycle action and returns the tungsten adhering to the inner surface of the arc tube 2 to the original tungsten electrode 3 to return to the arc tube 2.
For suppressing the blackening of. Further, in the present embodiment, in the arc tube 2, the main tube 6 and the side tube 8 are integrally formed by using the same material, but the main tube 6 and the side tube 8 are formed by different materials, It may be assembled afterwards.

The molybdenum wire 5 has a substantially circular cross section, and is connected to the tungsten electrode 3 via the tungsten wire 4. The closing body 9 is provided in a cylindrical shape on the molybdenum wire 5 so as to be inserted into the side tube 8 of the arc tube 2, and is inserted into the side tube 8 of the arc tube 2. Figure 2
FIG. 3 is a vertical cross-sectional view of a portion where a side tube 8 of an arc tube 2 is closed by a closing body 9.

The closing body 9 is composed of at least two material components including a molybdenum component which is a raw material of the molybdenum wire 5 and a silica component which is a component of the arc tube 2. The closing body 9 is obtained by firing a molded body in which a plurality of layers (for example, 5 layers) are concentrically stacked around the molybdenum wire 5. In order to distinguish each layer in the closed body 9 from each layer in the molded body before firing, the layer of the closed body 9 is hereinafter referred to as "sintered layer", and the layer of the molded body is hereinafter referred to as "molded layer". .

The closure 9 is composed of five sintered layers as described above, and the innermost layer on the molybdenum wire 5 is the first sintered layer 91.
And the outermost layer in contact with the inner peripheral surface of the side tube 8 of the arc tube 2 is the fifth layer.
Of the second sintered layer 92, the third sintered layer 93, and the fourth sintered layer in order from the inner layer side.
Of the sintered layer 94. Each sintered layer 91 to 9 of the closing body 9
In No. 5, the closer the molybdenum wire 5 is, the greater the molybdenum component content is and the less the silica component content is, and the closer it is to the side pipe 8, the more the silica component content is, the less the molybdenum component content is. It has become.

1-2. Method of Closing Arc Tube 1-2-1. First, a slurry corresponding to each of the first to fifth sintered layers 91 to 95 is prepared by a known method such as a ball mill. First
The slurry is a slurry for the first sintered layer 91, and the second
The slurry is a slurry for the second sintered layer 92, and similarly, the third slurry, the fourth slurry, and the fifth slurry are the same for the third sintered layer 93, the fourth sintered layer 94, and the fourth slurry. 5 for each of the sintered layers 95.

As shown in Table 1 below, each slurry 10 is prepared by mixing molybdenum powder as a component of the molybdenum wire 5, silica powder as a component of the arc tube 2, an organic binder, an organic solvent, a dispersant and the like. There is.

[0024]

[Table 1]

Here, molybdenum and silica in Table 1 are fine powders, and the size of the particle size is appropriately determined by the thickness of each sintered layer, the position of each sintered layer in all the sintered layers, and the firing conditions. . The organic binder may be a general ceramics-forming binder, and for example, polyvinyl alcohol, water-soluble acrylic, polyvinyl butyral, or the like is used, and in the present embodiment, water-soluble acrylic is used.
Butyl carbitol acetate is used as the organic solvent, and ammonium carboxylate is used as the dispersant.

As shown in Table 1, as the silica component increases, the compounding ratio of the organic solvent also increases. That is, in the first to fifth slurries, on the outer peripheral side (fifth slurry)
The blending ratio of the organic solvent becomes higher as it moves to slurry). This is because as the silica component in the slurry 10 increases, the viscosity of the slurry 10 increases and the compounding ratio of the organic solvent increases to adjust the viscosity of the slurry 10. The reason for adjusting the viscosity is to control the amount of the slurry 10 attached to the molybdenum wire 5 when the molybdenum wire 5 is dipped in the slurry 10.

FIG. 3 is a schematic view for explaining the manufacturing process of the closing body according to the present embodiment. As shown in the figure, the molybdenum wire 5 (diameter 0.4 mm) is dipped in the first slurry 10 with its axis being vertical. At this time, the molybdenum wire 5 is immersed in the slurry up to a predetermined position. And a predetermined speed, for example 10 cm
/ Min pull up vertically. Then, the pulled up molybdenum wire 5 is dried under a predetermined condition, for example, 70 ° C. for 3 minutes to form a first molding layer. The pulling rate is appropriately determined depending on the thickness of each molding layer and the viscosity of the slurry 10.

Thereafter, the second to fifth slurries 10 are used.
Using, the molding layers are sequentially laminated in the same manner as described above to prepare a molded body 11 (outer diameter of about 1.3 mm) in which the ratio of the constituent components changes in the radial direction. In addition, when dipping the molybdenum wire 5 into the second to fifth slurries 10,
The molybdenum wire 5 is dipped in each slurry so that the upper end of the first molding layer and the upper surface of the slurry are aligned with each other. By doing so, the upper end surfaces of the layers of the molded body 11 can be aligned in a substantially straight line. Next, the molybdenum wire 5 is formed so that the tip of the obtained molded body 11 (the lower end of the molded body 11 in FIG. 3) has a predetermined length (for example, 15 mm).
Is cut to leave the molybdenum wire 5 exposed from the tip of the molded body 11. The molded body 11 may be cut into a predetermined length by leaving the molybdenum wire 5 at both ends. In this case, since both ends of the molded body 11 are cut, the end surface of the molded body 11 can be finished in a straight line.

Next, the molded body 11 cut into a predetermined length is subjected to 500 ° C. in a non-oxidizing atmosphere, for example, a nitrogen atmosphere.
Let dry for 4 hours and remove. Then, in vacuum, 16
By performing firing at 00 ° C for 30 minutes in an electric furnace, the molded body 1
The closed body 9 which is the sintered body 1 is manufactured. In addition to the electric furnace, a heating device using a laser, a discharge plasma or the like as a heat source may be used for firing.

Next, a tungsten wire 4 is prepared and welded to one end of the molybdenum wire 5, and the tungsten wire 4 is further welded.
The tungsten electrode 3 is joined to the other end of the by a method such as welding. In this way, the closing body 9 in which the tungsten electrode 3 is connected to the molybdenum wire 5 is moved from the end of the side tube 8 of the arc tube 2 to the light emitting space 7 side so that the tungsten electrode 3 is on the light emitting space 7 side. After insertion, the outer peripheral portion of the side tube 8 is heated to 1700 ° C. to 1900 ° C. according to a known lamp sealing method using a heat source such as a burner or a laser, and the outer peripheral portion of the closing body 9 and the inner peripheral portion of the side tube 8 are heated. And are welded and sealed along the length direction of the closing body 9.

According to the above manufacturing method, the cylindrical closing body 9 can be easily manufactured. That is, each slurry 1
The molybdenum wire 5 is immersed in 0 to a predetermined position and pulled up at a constant speed.
0 can be easily attached. Moreover, since the molybdenum wire 5 is dipped into the slurry 10 and pulled up with the axis of the molybdenum wire 5 kept vertical, the slurry 10 is evenly attached to the outer periphery of the molybdenum wire 5.

At this time, the viscosity of the adhered slurry 10 is optimized so that it does not flow down, so that it is possible to reduce the thickness unevenness within the forming layer, and the shape of each forming layer is centered around the molybdenum wire 5. It can be made into a circular shape. Since the concentric shaped body is fired for the molybdenum wire 5, the concentric shaped closed body 9 in which the thickness of each of the sintered layers 91 to 95 is controlled can be easily obtained.
Also, the thickness of each molding layer can be changed easily by adjusting the pulling rate or the viscosity of the slurry 10. The viscosity of the slurry 10 is adjusted mainly by increasing or decreasing the blending ratio of the organic solvent. 2. Second Embodiment FIG. 4 is a side view of a molded body according to the second embodiment. The closed body according to the second embodiment of the present invention has the same structure as the closed body 9 shown in the first embodiment, except that the molded body before firing of the closed body is different. 11 is
That is, the varnish layer 20 is provided between the molybdenum wire 5 and the molded body according to the first embodiment.

The varnish layer 20 is made of an easily decomposable organic material, and is interposed between the molybdenum wire 5 and the first molding layer 111 when the molding 11 is molded, as shown in FIG. However, the varnish layer 20 itself disappears in the closed body after firing. The term “easily decomposable” means that the components are easily decomposed by heating. In the present embodiment, varnish is used as the easily decomposable organic material, and the varnish layer 20 is used in the debye process. Is decomposed by heat. In addition, in FIG. 4, reference numerals 112 to 115 denote the second parts of the molded body 11.
The molding layers of No. 5 to 5 are shown.

Hereinafter, a method of manufacturing the closed body having the varnish layer 20 at the time of molding will be described. First, as in the first embodiment, a varnish, an organic binder, an organic solvent,
A dispersant is mixed to prepare a slurry for the varnish layer 20. The lamination on the molybdenum wire 5 is performed by adding the molybdenum wire 5 to the slurry for the varnish layer 20 as in the first embodiment.
Is dipped into the slurry for the varnish layer 20 with its axis vertical, and the slurry adhering to the outer periphery of the molybdenum wire 5 is dried.
A varnish layer 20 having a thickness of μm is formed.

Next, similarly to the above-described first embodiment, the first molding layer 111 to the fifth molding layer 115 are sequentially laminated to manufacture a molded body 11, and this molded body 11 has a predetermined length. After cutting the tip to expose the molybdenum wire 5 from the tip of the molded body 11, the molded body 11 and the molybdenum wire are integrally removed under the same firing conditions as in the first embodiment. By baking and firing, a closed body that is a sintered body is obtained.

This molybdenum wire 5 and the first molding layer 111
Since the varnish layer 20 between and is an organic substance, it is decomposed in the debye step, and the molybdenum wire 5 and the first molding layer 11 before firing are decomposed.
An annular void layer remains between the two. Then, when the molded body 11 is fired with the void layer left, the void layer plays a role of canceling out the mismatch of expansion / contraction between the molybdenum wire 5 and the occluding body at the time of calcination, and the occluding body has no defect. Firing can be easily realized.

That is, when the firing is completed and the temperature is lowered to room temperature, the shrinkage of the closing body is larger than that of the molybdenum wire 5, and if firing is performed without providing the varnish layer 20, the first forming layer and the molybdenum of the forming body are moistened. Since the line is in contact with the wire, the plugging body may not be able to contract in the radial direction when the temperature is lowered after firing, and cracks may occur. However, when the molded body 11 including the varnish layer 20 between the molybdenum wire 5 and the first molding layer 111 is fired as in the present embodiment, the first molding layer 11 is fired before firing.
1 and the molybdenum wire 5 have a void layer remaining in an annular shape,
When the temperature is lowered, the closing body can shrink in the radial direction, and the conventional cracking can be prevented. Therefore, the varnish layer 20
By including, it is possible to improve the manufacturing yield, as compared with the case of firing a molded body not provided with a varnish layer. 3. Third Embodiment 3-1. Configuration FIG. 5 is a side view of a closing body showing a third embodiment of the present invention. As shown in the figure, the closing body 9 in the third embodiment is provided with a bonding layer 21 for connecting these between the closing body and the molybdenum wire 5 having the same structure as in the first embodiment. It is a thing.

The bonding layer 21 is formed on the outer periphery of the molybdenum wire 5 and contains an alloy sintered layer 211 containing manganese and molybdenum, and is formed on the outer periphery of the alloy sintered layer 211 and contains silica and alumina. An alumina sintered layer 212,
An alloy sintered layer 213 formed on the outer periphery of the alumina sintered layer 212 and having substantially the same composition as the alloy sintered layer 211 of the innermost layer.
It has and. Manganese in the alloy sintered layers 211 and 213 is a metal material having a lower melting point than the metal material (molybdenum) that is the main component of the closing body 9 and the molybdenum wire 5.

In the bonding layer 21 of the present embodiment as well, in order to distinguish each layer of the closed body 9 from each layer of the molded body before firing, the layer of the closed body 9 is referred to as an “alloy sintered layer”. ”,“ Alumina sintered layer ”, and the layer of the molded body,
These are called "alloy molded layer" and "alumina molded layer". 3-2. Manufacturing Method The alloy slurry for the alloy sintered layers 211, 213 of the bonding layer 21 and the alumina slurry for the alumina sintered layer 212 are prepared with the formulations shown in Table 2 below. The slurries for the respective sintered layers laminated on the outer periphery of the bonding layer 21 are the same as those in the first embodiment, and are prepared by the formulation shown in Table 1.

[0040]

[Table 2]

Then, the prepared sintered layers 211 to 21
Each slurry of No. 3 is laminated on the molybdenum wire 5 as in the first embodiment. That is, the molybdenum wire 5 is dipped in the alloy slurry for the alloy sintered layer 211, and the alloy slurry is attached to the outer circumference of the molybdenum wire 5. Then, the alloy slurry attached to the molybdenum wire 5 is dried to stack the alloy forming layer.

Next, the molybdenum wire 5 is dipped so that the entire alloy molding layer on the molybdenum wire 5 is dipped in the alumina slurry for the alumina sintered layer 212, and the alumina deposited on the outer periphery of the alloy molding layer is dipped. The slurry is dried to laminate the alumina molding layer. Then, again the alloy sintered layer 213
The molybdenum wire 5 is dipped so that the entire alumina molding layer on the molybdenum wire 5 is dipped in the alloy slurry for use, and the alloy molding layer is laminated on the outer periphery of the alumina molding layer.

Next, similarly to the first embodiment, a first molded layer to a fifth molded layer are sequentially laminated to form a molded body having a bonded molded layer (bonding layer 21 before firing). Is molded. Then, the molybdenum wire 5 is left so that the molded body has a predetermined length, and the tip thereof is cut to expose the molybdenum wire 5 from the tip of the molded body. Then, the obtained molded body is placed in a non-oxidizing atmosphere, for example, in a nitrogen atmosphere,
De-baiting is performed at 00 ° C. for 4 hours, and subsequently, in a hydrogen atmosphere whose dew point is adjusted to −5 ° C., firing is performed at a temperature equal to or higher than the melting point of manganese, for example, 1600 ° C. for 30 minutes to fire the compact. The closed body 9 is obtained.

In the closing body 9 thus obtained, during firing, the manganese of both alloy forming layers laminated inside and outside the alumina forming layer is oxidized by the vapor in the hydrogen atmosphere to become manganese monoxide. A glass layer (MnO + Al ₂ O ₃ + SiO ₂ ) having a high adhesion is formed on the alumina sintered layer 212 by manganese monoxide and alumina and silica in the formed alumina layer.

During firing, molybdenum in the inner and outer alloy molded layers is deposited on the surface side of the alumina molded layer. For this reason, in the inner alloy sintered layer 211, liquid phase sintering proceeds due to the molten manganese, the wettability with the molybdenum wire 5 increases, and the adhesion with the molybdenum wire 5 becomes stronger. In the outer alloy sintered layer 213, the molten manganese causes liquid-phase sintering of molybdenum precipitated from the alloy molded layer and molybdenum in the first molded layer on the outer side thereof to obtain a strong fixing force. To be As a result, the closing body 9 can be firmly bonded to the molybdenum wire 5 via the bonding layer 21.

In the present embodiment, the alloy sintered layer 211 of the bonding layer 21 has a manganese compounding ratio of 20 wt% as shown in Table 2, but it may be 1 wt% to 30 wt%. This is because if the compounding ratio of manganese is 0 wt%, the bonding layer 21 will not be liquid-phase sintered and will be solid-phase sintered, so that the bonding force cannot be improved. On the contrary, when the mixing ratio of manganese is more than 30 wt%, when the high pressure discharge lamp 1 is turned on and the temperature in the arc tube 2 rises, the manganese in the alloy sintered layers 211, 213 is evaporated and the high pressure discharge is generated. This is because the emission color of the lamp 1 may be changed.

As shown in Table 2, the alumina sintered layer 212 has a silica compounding ratio of 4 wt%, but 1 wt.
% -5 wt% is sufficient. This is because if the compounding ratio of silica is 0 wt%, the glass layer cannot be made to appear in the bonding layer 21, and conversely, if the silica content is more than 5 wt%, the mechanical strength of the alumina sintered layer 212 decreases. The reason is that

The molded body is fired in a hydrogen atmosphere whose dew point is adjusted to -5.degree. C. after removing the by-pass, but the dew point in the hydrogen atmosphere may be -20.degree. C. to -5.degree. If the dew point in the hydrogen atmosphere is in the range of -20 ° C to -5 ° C,
This is because manganese in the alloy forming layer selectively reacts with steam in a hydrogen atmosphere and is oxidized into manganese monoxide. Although the present invention has been described above based on the respective embodiments, it goes without saying that the content of the present invention is not limited to the specific examples shown in the respective embodiments, and for example, the following modified examples. It can be carried out.

(1) Molded Body Manufacturing Process In each of the above-described embodiments, in the manufacturing process for manufacturing the molded body 11, the metal introduction wire (molybdenum wire 5) is left in a state where its axis is vertical, Although the slurry 10 is attached to the metal introduction line after being dipped in the slurry 10 and then pulled up, for example, the metal introduction line is dipped into the slurry 10 with its axis being horizontal to introduce the metal introduction line. The slurry 10 may be attached to the wire.

However, in the horizontal state, the metal lead-in wire is slurried 1
When it is pulled up from 0, the adhered slurry 10 may hang down from the metal introduction line, and the concentric molded body 11
Although it is difficult to obtain the above, such a problem can be eliminated by rotating the metal introducing wire, for example. further,
In the method of horizontally dipping the metal introducing line in the slurry 10, if the forming layer is laminated on the metal introducing line, even if the metal introducing line is not dipped in the slurry 10, the forming layer on the metal introducing line Slurry only the surface layer 1
The slurry 10 can be attached to the molding layer only by dipping it to zero.

(2) Organic substance layer a) Position of organic substance layer In the second embodiment, the organic substance layer (varnish layer 2) is used.
0) was laminated before the first molding layer 111, that is, on the metal introduction wire (molybdenum wire 5), the first molding layer 11
An organic material layer may be laminated before the molding layers 112 to 115 other than 1. Also in this case, the thermal stress at the time of cooling the closing body 9 to room temperature after firing can be relaxed, and the occurrence of cracks can be prevented to some extent. However, considering the shrinkage of the closing body 9 after firing, since the inner circumference of the molded body 11 is the largest, an organic material layer is laminated before the first molded layer 111 as in the second embodiment. However, it is considered to be most effective for the occurrence of cracks.

In the second embodiment, the case where the organic material layer is disposed only between the metal introduction line and the first molding layer 111, that is, only one layer is described, but the organic material layer is limited to one layer. Without considering the sintering characteristics of the material selected for the closing body 9 and the metal introduction line, the forming layer 111 of the forming body 11
There is no problem even if they are provided in a lower layer of a plurality of layers among the above-mentioned layers. However, if many organic material layers are provided on the molded body 11,
Since this organic material layer remains as a void layer in the debye step, when the molded body 11 is fired, the sintered layers 91 to 9 of the closing body 9 are formed.
There is a risk that the adhesion between the five will decrease. Therefore, the number of layers of the organic material layer must be appropriately determined depending on the number of sintered layers of the closed body, the size, the material (coefficient of linear expansion), and the like.

B) Material of Organic Material Layer Although varnish was used as the organic material of the organic material layer, any organic material that is easily decomposable so that the organic material layer decomposes in the debye step to form a void layer, for example, , Wax, starch and the like can be used. Further, the slurry for the organic material layer does not contain a component that constitutes the closing body 9, for example, a metal component, but if the organic material layer is decomposed in the debye process and a void layer can be formed in the molded body 11, the closing body 9 is formed. The powder of the metal component or the powder of another metal constituting the above may be included in some amount.

C) Thickness of Organic Layer In the second embodiment, the thickness of the varnish layer 20 is about 5 μm. If the thickness of this varnish layer 20 is too thin, when the temperature is lowered from the firing temperature at the time of firing to room temperature, the inner periphery of the closing body 9 cannot come into contact with the metal introduction line and contract in the radial direction, and cracks occur. On the contrary, if it is too thick, a gap may remain between the closing body 9 and the metal introducing wire when the temperature is lowered to room temperature, or the high pressure discharge lamp 1 is turned on and the temperature inside the arc tube 2 is increased. Occasionally, the closing body 9 and the metal lead-in wire may expand to form a void therebetween.

Therefore, the thickness of the organic material layer is such that cracks do not occur on the inner peripheral side of the closing body 9 when the temperature is decreased from firing to room temperature, and the high pressure discharge lamp 1 is turned on.
It is sufficient that voids are not generated between the metal introducing line and the closing body 9 or between the sintered layers in the closing body 9 when the temperatures of the metal introducing line, the arc tube 2 and the closing body 9 rise. For this reason,
The thickness of the organic material layer depends on the metal introduction line, the closing body 9 and the arc tube 2.
It is necessary to determine each time according to each dimension (diameter) and coefficient of thermal expansion.

(3) Bonding Layer a) Position of Bonding Layer In the above-described third embodiment, the bonding layer 21 is provided below the first sintered layer 91, that is, on the metal introduction line. The bonding layer 21 may be provided below the sintered layers 92 to 95 other than the sintered layer 91.

Further, in the third embodiment, the bonding layer 2
1 has been described only between the metal introduction line and the first sintered layer 91, that is, only one layer has been described.
Is not limited to one layer, and the sintered layer 9 of the closing body 9
The bonding layer 21 may be provided below the plurality of sintered layers of 1 to 95. Even if the number and position of the bonding layers 21 are different from those in the embodiment as described above, the bonding layers 21 are strong with the metal introduction line inside thereof and the first sintered layer 91 or the sintered layers inside and outside thereof. Can be combined with.

Regarding the position of the bonding layer 21 in the closing body 9, considering that the temperature inside the arc tube 2 becomes high when the high pressure discharge lamp 1 is turned on, the thermal stress caused by the difference in the thermal expansion coefficient is The largest distance is between the lead-in line and the innermost layer of the closure body 9, and peeling is easy during this time. Therefore, it is considered most effective that the closing body 9 has the bonding layer 21 in the innermost layer thereof.

B) Material of Sintered Alloy Layer in Bonding Layer In the third embodiment, the sintered alloy layer 21 in the bonding layer 21 is used.
Although powder of molybdenum, which is the same material as the metal lead-in wire, was used as the powder of the third metal material forming the elements 1 and 213, for example, powder of tungsten or powder of mixed molybdenum and tungsten may be used. Furthermore, powders of other metal materials may be used. However, when using another metal material, the melting point of the metal material needs to be higher than that of manganese and higher than the firing temperature. This is because the powder of the metal material is liquid-phase sintered by manganese in the alloy sintered layers 211 and 213 during firing.

(4) Metal Layer In the third embodiment, as the bonding layer 21, molybdenum and manganese are used for the alloy sintered layers 211 and 213, and the glass layer is formed on the alumina sintered layer 212. However, for example, instead of the bonding layer 21, a metal layer containing a metal material, such as manganese, lower than the melting point of the metal introduction line and the melting point of the third metal material forming the layer near the metal introduction line of the molded body. You may comprise only. Of course, the bonding layer 21 and the metal layer may be used together.

Also in this case, since the metal layer is liquid-phase-sintered with manganese which melts both the molybdenum of the first molding layer 111 and the molybdenum of the metal lead-in wire, the closing body 9 is formed of the metal layer. It can be firmly bonded to the metal introduction line via. When the ratio of manganese in the metal layer becomes high, as described in the third embodiment, when the high pressure discharge lamp 1 is turned on and the temperature inside the arc tube 2 rises, the alloy sintered layer 211, Manganese in 213 may evaporate and change the emission color of the high pressure discharge lamp 1.
Therefore, the mixing ratio of manganese contained in the metal layer is preferably 1 wt% to 30 wt% as in the third embodiment. In this case, the bonding layer 21 in the third embodiment
The alloy layer and the metal layer here have the same structure.

A) Position of Metal Layer and Number of Layers In the above-mentioned example, similar to the third embodiment, the closing member 9 is used.
Was provided with a metal layer under the first sintered layer 91,
A metal layer may be provided below the sintered layers 92 to 95 other than the first sintered layer 91. Further, the metal layer is not limited to one layer, and a metal layer may be provided below the plurality of sintered layers among the sintered layers 91 to 95 of the closing body 9. Even in such a case, since the metal layer undergoes liquid phase sintering with molybdenum in the forming layers on the inner and outer sides thereof, the metal layer can be firmly bonded to the sintered layers on both sides of the metal layer. Regarding the position of the metal layer in the closing body 9, it is considered most effective to provide it in the innermost layer of the closing body 9 for the same reason as in the above 3-1.

B) Material of the metal layer and its melting point In the above-mentioned metal layer, molybdenum (melting point: about 2620 ° C.) is used as the first metal material forming the metal introduction line and the layer near the metal introduction line of the molded body. However, as a second metal material having a melting point lower than that of molybdenum, manganese (melting point: about 124
Although an example using 4 ° C.) has been described, a material other than manganese may be used as the second metal material. For example, molybdenum, tungsten (melting point:
When using about 3380 ℃, iron (melting point is about 15
35 ° C.), chromium (melting point is about 1900 ° C.) and the like can be used.

Considering the temperature of the arc tube 2 when the high pressure discharge lamp 1 is turned on, the melting point of these second metallic materials is preferably higher than that temperature (some of them reach about 900 ° C.). This is to prevent the second metal material from melting during lighting. Among the second metal materials exemplified above, manganese has the best wettability with metals such as molybdenum and tungsten.

(5) Closure body a) Concerning the material of the closure body In each of the above-described embodiments, the components constituting the closure body 9 are defined on the premise of the arc tube 2 of quartz glass and the metal lead-in wire of molybdenum. Although the description has been given with respect to the combination of molybdenum-silica (see Table 1), other combinations may be used. For example, when tungsten is used for the metal introduction line, tungsten-silica, and when light-transmissive alumina is used for the arc tube 2,
A combination of tungsten-alumina and molybdenum-alumina may be used.

Furthermore, it is not necessary to match the material of the metal introducing line with the material forming the closing body 9. For example, molybdenum is used for the metal introducing line, and the component forming the closing body 9 is made of tungsten-silica or tungsten. -Alumina or the like may be used, and further, the metal component forming the closing body 9 may be a mixture of two materials of tungsten and molybdenum.

Further, the closing body 9 can be made of a material other than molybdenum, tungsten, silica and alumina. Needless to say, as such a material, when the high-pressure discharge lamp 1 is turned on and the temperature inside the arc tube 2 rises, the material can sufficiently withstand use at this temperature. Further, considering the difference in thermal expansion characteristics between the arc tube 2 and the metal introduction line when the high-pressure discharge lamp 1 is turned on, a metal material having a characteristic closer to the coefficient of thermal expansion of the metal introduction line than the coefficient of thermal expansion of the arc tube 2. It is preferable that the closing body 9 is made of a material having a characteristic closer to that of the arc tube 2 than that of the metal introduction line. It should be noted that if the structure of the closing body 9 is changed to another material, the firing conditions of the molded body will naturally be changed.

B) Regarding the Number of Layers of Closing Body In each of the above-mentioned embodiments, the case of the closing body 9 having a five-layer structure has been described. However, the layer construction of the closing body 9 includes a metal lead wire and an arc tube 2. From the viewpoint of relaxing the thermal stress caused by the difference in the coefficient of thermal expansion, it seems preferable to have a multilayer structure as much as possible.

[0069]

As described above, in the method for manufacturing the arc tube sealing closure of the discharge lamp according to the present invention, the metal introduction wire for supplying power to the electrodes in the arc tube is provided with substantially concentric circles. A method of providing a molded body having a structure in which a plurality of layers are stacked, and obtaining a closed body by firing the molded body, comprising: a slurry preparation step of preparing a slurry for each layer of the molded body; And then drying the adhered slurry, and then sequentially dipping, adhering, and drying the second layer to the outermost layer, and then repeating the step of forming a molded body. Therefore, the slurry can be easily attached to the metal lead wire,
Productivity can be improved. Moreover, for example, in the state where the axis of the metal lead wire is vertical, when the metal lead wire is dipped and pulled up, the slurry can be attached concentrically around the metal lead wire,
A molded body in which the thickness of each layer is controlled can be obtained. Therefore, a high-quality blocker can be easily obtained.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing a configuration of a high pressure discharge lamp according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a side tube of the arc tube according to the first embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining a manufacturing process of the closing body which is the first embodiment of the present invention.

FIG. 4 is a side view of a molded body according to a second embodiment of the present invention.

FIG. 5 is a side view of a closing body according to a third embodiment of the present invention.

[Explanation of symbols]

1 High-pressure discharge lamp 2 arc tube 3 Tungsten electrode 5 molybdenum wire 7 luminous space 8 side pipe 9 occluders 91 First Sintered Layer 92 Second sintered layer 93 Third Sintered Layer 94 Fourth sintered layer 95 Fifth sintered layer 20 varnish layer 21 Bonding layer 211 Sintered alloy layer 212 Alumina sintered layer 213 Sintered alloy layer

Claims (16)

[Claims] 1. A method for obtaining a closed body by providing a molded body having a structure in which a plurality of substantially concentric layers are laminated on the outer periphery of a metal introduction wire for supplying power to an electrode in an arc tube, and firing the molded body. Then, a slurry preparation step of preparing a slurry for each layer of the molded body, and dipping the metal introduction wire into the slurry of the innermost layer, and drying the attached slurry, and then from the second layer to the slurry of the outermost layer, A method for producing a closed body for sealing an arc tube of a discharge lamp, comprising: a step of sequentially forming a molded body, which is repeated by dipping, adhering, and drying. 2. The discharge lamp according to claim 1, wherein, in the step of producing the molded body, the metal lead wire is dipped into the slurry and pulled up while the posture of the metal lead wire is kept vertical. 2. A method for manufacturing a closing body for sealing an arc tube. 3. A cutting step of cutting the molded body to a predetermined length leaving the metal introducing line so that the metal introducing line is exposed from the molded body after the molding body producing step. The method for producing a closing body for sealing an arc tube of a discharge lamp according to claim 1 or 2. 4. The slurry preparing step includes a step of preparing a slurry containing an easily decomposable organic material, and the molded body preparing step comprises stacking at least one layer of a plurality of layers of the molded body. Before, the metal introduction wire is dipped into a slurry containing the easily decomposable organic material,
The method for producing a blocking body for sealing an arc tube of a discharge lamp according to any one of claims 1 to 3, comprising a step of drying the attached slurry to stack an organic material layer. 5. The method according to claim 4, wherein the organic material layer is laminated before laminating the innermost layer of the molded body. 6. The method for manufacturing an arc tube sealing closure of a discharge lamp according to claim 4, wherein the easily decomposable organic material is a varnish. 7. The slurry for the layer of the molded body, which is closer to the metal introduction line, is a powder of a first metal material having a characteristic closer to the coefficient of thermal expansion of the metal introduction line than the coefficient of thermal expansion of the arc tube. Including, the slurry preparation step includes a step of preparing a slurry containing a powder of a second metal material having a melting point of the metal introduction line and a melting point of the first metal material lower than the melting point of the first metal material, Before laminating at least one layer of the plurality of layers of the molded body, the metal lead wire is dipped in a slurry containing the powder of the second metal material, and the attached slurry is dried to form a metal layer. Including a step of laminating the molded body produced in the molded body producing step at a temperature higher than the melting point of the second metal material and lower than the melting point of the metal introducing wire and the melting point of the first metal material. Characterized by firing A method for manufacturing a closing body for sealing an arc tube of a discharge lamp according to claim 1. 8. The method according to claim 7, wherein the metal layer is laminated before laminating the innermost layer of the molded body. 9. The method for manufacturing an arc tube sealing closure of a discharge lamp according to claim 7, wherein the second metal material is manganese. 10. The slurry for a layer of the molded body, which is closer to the metal introduction line, is a powder of a third metal material having a characteristic closer to that of the metal introduction line than that of the arc tube. Including the step of preparing an alloy slurry containing at least one of the powder of the material of the metal introduction wire and the powder of the third metal material, and the powder of manganese; and the alumina powder. And a step of preparing an alumina slurry containing silica powder, wherein the molded body preparation step comprises: before laminating at least one layer of the plurality of layers of the molded body, the metal introducing wire, the alloy slurry. And dipping the adhered alloy slurry to laminate the alloy layer, and dipping the metal lead wire on which the alloy layer is laminated into the alumina slurry and depositing the adhered alumina slurry. And a step of drying the alumina layer to stack an alumina layer, and a step of dipping the metal lead wire on which the alumina layer is stacked into the alloy slurry and drying the deposited alloy slurry to stack the alloy layer. A dew point of the molded body produced in the molded body forming step is −2 including a layer forming step.
The firing is performed in a hydrogen atmosphere adjusted to 0 ° C. to −5 ° C. at a temperature higher than the melting point of manganese and lower than the melting point of the metal introducing wire and the melting point of the third metal material. 7. A method of manufacturing a closing body for sealing an arc tube of a discharge lamp according to claim 6. 11. The method for manufacturing the arc lamp sealing closure for a discharge lamp according to claim 10, wherein the bonding layer forming step is performed before the innermost layer of the molded body is laminated. . 12. The method for manufacturing an arc tube sealing closure of a discharge lamp according to claim 10, wherein the material of the metal lead-in wire is tungsten or molybdenum. 13. The powder of the third metal material contains at least one of a powder of tungsten and a powder of molybdenum, according to any one of claims 10 to 12. A method of manufacturing a closing body for sealing an arc tube of a discharge lamp. 14. In the slurry preparation step, the manganese content of the alloy slurry is 1 to 30 wt%, and the silica content of the alumina slurry is 1 to 5 wt%.
It is set as any one of Claims 10-13 characterized by the above-mentioned.
Item 7. A method for manufacturing a closing body for sealing an arc tube of a discharge lamp according to item. 15. A closure for sealing an arc tube, which is manufactured by the manufacturing method according to any one of claims 1 to 14. 16. A discharge lamp in which an arc tube is sealed by using the arc tube sealing closure according to claim 15.