JP2000123792A - Inclined function material, lamp sealing body, their manufacture and lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form an airtight sealed structure, to attain a stable operating characteristic and to prolong the operating life by forming a hole on the outer face of an insulating inorganic material layer, extending in the laminating direction and partitioning a peaked space at the tip section. SOLUTION: A rod-like lower hole forming mold member 23 conically peaked at the tip section 23A is erected to extend upward in the vertical direction at the center of the bottom member 21 of a mold die 20 having a columnar mold space. A rod-like upper hole forming mold member 24 is installed to extend downward in the vertical direction at the center of the lower face of a pressing member 22. The tip section 23A of the lower hole forming mold member 23 has a peaked shape. When mixed powder of insulating inorganic material powder or conductive inorganic material powder is filled in the die 20, the powder slides down without accumulating on the tip face of the mold member 23, thus regions having different thermal expansion coefficients are not locally formed on an obtained inclined functional material, particularly on the bottom wall section of an electrode rod insertion hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a functionally graded material, a sealed body for a lamp, a method for manufacturing the same, and a lamp.

[0002]

2. Description of the Related Art A functionally graded material is composed of, for example, a mixed sintered body of a conductive inorganic material component composed of a metal and an insulating inorganic material component composed of a metal oxide. When the substance component concentration changes in a gradient or stepwise manner, the conductive portion having a high conductive inorganic substance component concentration and the insulating portion having a conductive inorganic substance component concentration of zero or the low concentration are located at different places. It is a one-piece solid material that is located, and is suitably used as a sealing body that forms a current supply path, for example, in the configuration of a seal portion of a lamp.

Conventionally, as a method for producing such a functionally gradient material, a dry method has been advantageously used. In this dry method, for example, by mixing a conductive inorganic material powder made of, for example, molybdenum and an insulating inorganic material powder made of, for example, silica at different ratios, a plurality of mixed powders having different conductive inorganic material powder content ratios Is prepared, usually, in a molding die, first, only the insulating inorganic material powder not containing the conductive inorganic material powder is filled using gravity to form an insulating inorganic material powder layer, On top of this, the mixed powder having the lowest concentration of the conductive inorganic substance powder is filled in layers in order, thereby forming a plurality of mixed powder layers to form a powder laminate. Then, by heating and sintering the powder laminate thus obtained to form an integrated sintered body, a plurality of constituent layers each having a uniform concentration of the conductive inorganic substance component are directed upward from below. Thus, a functionally graded material laminated in such a manner that the concentration of the conductive inorganic substance component is gradually increased step by step is manufactured.

When such a functionally graded material is actually used as a sealing body for a lamp, it is necessary to connect a lead bar to the functionally graded material in an electrically connected state. . In order to achieve this, in the past, in a temporarily sintered body obtained by temporarily sintering the powder laminate, a lead rod insertion hole extending from the end face in the laminating direction, for example, by cutting using a cutting drill. A lead rod is inserted into one end of the lead laminated body, and the powder laminate is heated and fired in this state to perform a main sintering process, whereby the lead rod is integrally fixed to the functionally graded material to seal the lamp. Methods of manufacturing a stop have been used.

[0005] However, the above-mentioned method is considerably disadvantageous in terms of manufacturing in that a cutting process of the pre-sintered body is required, so that a bottom surface of the molding die for forming the powder laminate is provided. A rod-shaped hole forming member is protruded so as to protrude upward from the mold, a powder laminated body is formed using this mold, and a slope for forming a lead rod insertion hole by removing the hole forming member is formed. A method for producing a functional material has been proposed.

However, in the lamp using the lamp sealing body obtained by such a method, cracks correspond to the functionally graded material in the vicinity of the distal end of the base end portion of the lead rod inserted and fixed in the functionally graded material. Has been found to occur at a frequency of After studying the cause of this problem, in the functionally graded material, the layer where the tip of the proximal end of the lead rod was located was
In order to achieve a sufficient electrical connection, it is necessary that the conductive inorganic substance component has a substantially conductive layer having a concentration of, for example, 20% by volume or more. It has been found that a region made of an insulating inorganic substance component is locally formed in the layer portion where the tip of the end portion contacts.

[0007] In the production of a functionally gradient material, a molding die is first filled with an insulating inorganic substance powder by using gravity. This is because the insulating inorganic substance powder is deposited on the end face. That is, in the bottom wall portion of the hole of the functionally graded material, an insulating inorganic material component region having a locally different coefficient of thermal expansion is formed in a state of being in contact with the distal end portion of the base end portion of the lead rod. Naturally, in the region, the electric resistance is large, and the region has a different composition state from its surroundings.
It is considered that these cause cracks in the functionally gradient material.

[0008]

DISCLOSURE OF THE INVENTION The present invention has been made based on the above findings, and its object is to provide:
There is no locally different area of thermal expansion on the bottom wall of the hole extending in the stacking direction, and no large local thermal stress occurs in the portion surrounding the hole, and therefore, sufficient thermal durability Another object of the present invention is to provide a functionally gradient material having: Another object of the present invention is to provide a method capable of reliably and advantageously producing the functionally gradient material having the above-mentioned effects.

Another object of the present invention is that the above-mentioned functionally graded material and the lead rod are integrally fixed, and even when the lead rod is heated to a high temperature, the temperature distribution becomes gently inclined. An object of the present invention is to provide a lamp encapsulant that does not cause a large local thermal stress, and to provide a method for reliably and advantageously producing such a lamp encapsulant.

It is a further object of the present invention to provide a lamp having a hermetically sealed structure formed by the above-described lamp sealing body, and having stable operating characteristics and a long service life.

[0011]

The functionally graded material of the present invention comprises an insulating inorganic material layer and a plurality of mixture layers each comprising a mixture of a conductive inorganic material component and an insulating inorganic material component. In each of the mixture layers, in the laminate in which the ratio of the conductive inorganic material component increases stepwise in order from the one adjacent to the insulating inorganic material layer, an opening is formed on the outer surface of the insulating inorganic material layer and the stacking direction is changed. And a hole that defines a pointed space at the tip end is formed.

The method for producing a functionally graded material according to the present invention is characterized in that the insulating inorganic material powder is placed in a molding die having a rod-shaped hole forming molding member having a pointed tip at the bottom. Filling to form an insulating inorganic material powder layer, and mixing a plurality of conductive inorganic material powders having different proportions of the conductive inorganic material powder, prepared by mixing the conductive inorganic material powder and the insulating inorganic material powder at a predetermined ratio. By filling the powder into the mold in order of the proportion of the conductive inorganic substance powder, the proportion of the conductive inorganic substance powder is sequentially increased upward on the insulating inorganic substance powder layer. A step of forming a plurality of mixed powder layers by laminating, and pressing the laminated powder layers integrally, and then removing the molding member for forming holes to obtain a pressed molded body having holes. It is characterized by having. Here, it is preferable that the tip of the molded member for forming a hole has a conical shape and the opening angle of the top is 20 to 100 degrees.

A sealed body for a lamp according to the present invention comprises the above-described functionally graded material and a lead rod having a base end portion inserted into a hole of the functionally graded material and integrally fixed thereto, The distal end of the proximal end portion of the lead rod has a pointed shape that matches the shape of the hole of the functionally graded material. Here, the lead rod preferably has a configuration in which the outer diameter of the distal end portion protruding and extending from the functionally graded material is larger than the outer diameter of the proximal end portion.

According to a method of manufacturing a sealed body for a lamp of the present invention, a base end portion of a lead rod is inserted into a hole of a press-formed body manufactured by the above-described method. By performing a sintering process on the body, a sealed body for a lamp is obtained in which a lead rod is integrally fixed to a functionally gradient material made of a sintered body.

A lamp according to the present invention is characterized in that a hermetic sealing structure is formed by the above-mentioned lamp sealing body.

[0016]

According to the functionally graded material of the present invention, the tip of the hole that opens to the outer surface of the insulating inorganic material layer and extends in the laminating direction has a pointed shape. Since the temperature distribution is gentle in the direction of laminating the functional material and the temperature distribution in the portion surrounding the tip of the hole is also gentle, no large thermal stress is generated locally.

In the method for producing a functionally graded material of the present invention, in the production of a functionally graded material by a dry method, a molding die on which a molding member for forming a hole having a pointed tip is used. A functionally graded material having desired characteristics can be manufactured without locally forming regions having different coefficients of thermal expansion on the bottom wall of the hole. The tip of the hole forming member has a conical shape, and the opening angle of the vertex is 20 to 1.
When the angle is 00 degrees, the above-described operation and effect can be reliably obtained.

In the sealed body for a lamp according to the present invention, the tip of the base end portion of the lead rod inserted into the hole of the functionally gradient material has a sharp tip adapted to the shape of the hole of the functionally gradient material. Because of the head shape, the fixed state or the connection state of the two are tight, and the boundary surface between the two is inclined in the axial direction (length direction) of the lead rod. Even in the case where the temperature gradient changes gradually in the portion surrounding the distal end portion of the base end portion of the lead rod, large thermal stress does not locally occur in the functionally gradient material.

Further, in the sealed body for a lamp of the present invention, since the outer diameter of the base end portion of the lead rod inserted into the hole of the functionally gradient material is small, thermal expansion due to temperature change of the lead rod itself is prevented. Since the degree is suppressed to be small, the stress generated in the functionally gradient material surrounding the base end portion can be reduced.

In the method for producing a sealed body for a lamp according to the present invention,
The base end portion of the lead rod is inserted into the hole of the press-molded body manufactured by the above-described method, and in this state, the sintering process of the press-molded body is performed, whereby the inclined body made of the sintered body is formed. The lead rod is integrally fixed to the functional material, so that the lamp sealing body having the above-described effects can be advantageously and reliably manufactured.

In the lamp of the present invention, a thermally stable hermetic sealing structure is formed by the above-mentioned lamp sealing body, so that stable operating characteristics can be obtained and the service life can be prolonged.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. FIG. 1 is an explanatory sectional view showing an example of the configuration of the functionally gradient material of the present invention. In the functionally graded material 10, an insulating inorganic material layer 11 located at the lowermost layer and a uniform mixture of an insulating inorganic material component and a conductive inorganic material component laminated on the insulating inorganic material layer 11. And a plurality of mixture layers 12 of which are stacked in a state in which the concentration of the conductive inorganic substance component increases in a gradient or stepwise manner in one specific direction (upward in the figure).

An electrode rod insertion hole 13 is formed at the outer end face of the insulating inorganic material layer 11 to extend upward and extend through several layers below the insulating inorganic material layer 11 and the mixture layer 12. Is formed. The electrode rod insertion hole 13 has a shape in which the distal end portion 13A defines a conical space, in other words, has a mortar-shaped bottom wall portion. On the other hand, there is formed an external lead rod insertion hole 14 which is opened at the outer end face of the mixture layer 12 located at the uppermost layer, extends downward, and penetrates several layers in the upper part of the mixture layer 12.

Here, specific examples of materials suitably used as the insulating inorganic substance component include, for example, silica glass, quartz (SiO ₂ ), alumina (Al ₂ O ₃ ), zirconia (ZrO ₂ ), and magnesia (MgO ₂ ). ), Silicon carbide (SiC), titanium carbide (TiC), silicon nitride (S
i ₃ N ₄ ), aluminum oxynitride (AlON) and the like. Further, specific examples of a material suitably used as the conductive inorganic substance component include, for example, molybdenum, nickel, tungsten, tantalum, chromium, platinum, zinc, and the like. The above-mentioned conductive inorganic substance powder and insulating inorganic substance powder need to have high purity, and for example, those having a purity of 99.9% or more are preferably used. The average particle size of both the conductive inorganic material powder and the insulating inorganic material powder is preferably 0.01 to 10.0 μm, particularly preferably 0.1 to 5.0 μm.

The shape of the electrode rod insertion hole 13 is, for example, 0.3 to 3.0 mm in outer diameter and 10 to 20 mm in length.
The shape of the external lead rod hole 14 is, for example, 0.3 to
The length is 3.0 mm and the length is 5 to 10 mm. The tip of the electrode rod insertion hole 13 extending from the insulating inorganic material layer 11 is
It is preferable that the content ratio of the conductive inorganic substance component reaches 20% by volume or more, more preferably 40% by volume or more.
The shape of the space of the distal end portion 13A of the electrode rod insertion hole 13 may be a pointed shape, and may be a shape other than a conical shape.

The functionally gradient material of the present invention is manufactured as follows. FIG. 2 is an explanatory cross-sectional view showing a method for producing a functionally graded material of the present invention. In this figure, at the center of the bottom member 21 of the molding die 20 having a cylindrical molding space, a bar-shaped lower hole forming molding member 23 having a conical pointed tip 23A is formed in a vertical direction. It is erected to extend upward. On the other hand, at the center of the lower surface of the pressing member 22, a rod-shaped upper hole forming member 24 is installed so as to extend vertically downward.

As the material of the lower hole forming member 23 and the upper hole forming member 24, a metal material for forming a mold or the like can be used. For example, an organic high molecular substance that evaporates and disappears can be used. Specific examples of the organic polymer substance include, for example, synthetic resins such as acrylic resin, polypropylene, and polystyrene, but those which do not produce any solid residue after disappearance are particularly preferable.

The shapes of the lower hole forming member 23 and the upper hole forming member 24, for example, the outer diameter and the length, are as described later. Alternatively, since the external lead rod insertion hole is formed, the shape is determined by the shape required for the target electrode rod insertion hole or the external lead rod insertion hole. For example, an example of the lower hole forming member 23 for the electrode rod insertion hole 13 has an outer diameter of 0.3 to 3 mm and a length of 5 to 20 mm.
An example of the upper hole forming member 24 for 4 has an outer diameter of 0.3 to 3 mm and a length of 2 to 5 mm.

In the present invention, the tip 23A of the lower hole forming member 23 has a pointed shape. Here, the “pointed shape” means that the outer surface of the distal end portion of the cylindrical rod-shaped body constituting the lower hole forming molded member 23 is inclined with respect to the axis of the rod-shaped body, for example, as shown in FIG. As shown in the figure, a shape having a conical tip 23a whose diameter gradually decreases as the outer diameter approaches the tip, and a bamboo spear-shaped tip 2 cut off by a plane obliquely intersecting the axis as shown in FIG.
3b, or a shape similar thereto, but the tip is not limited to a sharp one and may be rounded in a shell shape. And the tip is a conical tip 2
In the case of 3a, the magnitude of the opening angle α at the top is preferably in the range of, for example, 20 to 100 degrees, and more preferably in the range of 30 to 60 degrees.

The means for fixing the lower hole forming member 23 to the bottom member 21 of the mold 20 or the means for fixing the upper hole forming member 24 to the pressing member 22 are not particularly limited. Rather, they can be freely selected. In some cases, the molded members for forming holes may be detachable from the support.

A functionally graded material is manufactured in the same manner as in the prior art, except that a molding die 20 having the lower hole forming molding member 23 provided on the bottom member 21 as described above is used. That is, first, an insulating inorganic material powder made of, for example, silica is dropped into the mold 20 using gravity and filled, and if necessary, pressurized to form a layered body. Then, an insulating inorganic material powder layer 25 is formed. On the other hand, for example, a conductive inorganic material powder made of molybdenum,
By mixing the insulating inorganic material powder made of silica at different ratios, a plurality of mixed powders having different conductive inorganic material powder content ratios are prepared. Then, the mixed powder having the lowest concentration of the conductive inorganic material powder is filled into the mold 20 in a layered manner in order, and if necessary, pressurized to form a layered body. , Forming a plurality of mixed powder layers 26 to form a powder laminate. The powder laminate formed here is buried from the lower surface so that the lower hole forming member 23 protrudes upward.

In the state where the required powder laminate is formed, the pressurizing member 22 is lowered, whereby the upper hole forming molding member 24 fixed to the pressurizing member 22 is powder-laminated. It is pushed downward from the upper surface of the body. Then, the powder laminate is further pressed from above by the pressing member 22, thereby forming a laminate molded body that is a pressure molded body.

The length and diameter of the laminated molded product, the thickness of each constituent layer and the number of constituent layers are not particularly limited.
It is appropriately selected according to the actual use of the functionally graded material. Typically, for example, the length is 10 to 40 mm, the diameter is 2 to 15 mm, and the thickness of each constituent layer is different depending on the concentration of the conductive inorganic substance component.
２2 mm, and the number of constituent layers is 10-20 layers.

The laminated molded product taken out of the mold 20 is
For example, when the lower hole forming member 23 and the upper hole forming member 24 are removed, they basically have the form shown in FIG. This laminated molded body is then subjected to a sintered body forming step. In this sintered body forming step, the laminated molded body is subjected to, for example, 10
Heat treatment is performed with a maximum heating temperature of 00 to 1200 ° C. When all of the lower hole forming member 23 and the upper hole forming member 24 are made of, for example, an organic polymer material, all of the members are subjected to a heat treatment on the laminated molded body as they exist. Can be evaporated and eliminated by thermal decomposition or the like.

In this manner, the shape of the space of the distal end portion 13A corresponds to the pointed shape of the distal end portion of the lower hole forming molding member 23, and the electrode rod insertion hole 13 and the external The functionally graded material 10 of the present invention shown in FIG. 1 in which the lead rod insertion holes 14 are formed to extend in the axial direction from both end faces.
Is formed.

According to this method for producing a functionally graded material, the tip 23A of the lower hole forming member 23 is pointed, so that the insulating inorganic material powder or the mixed powder of the insulating inorganic material powder and the conductive inorganic material powder is used. Is filled in the mold 20, the powder slides down without accumulating on the tip end surface of the lower hole forming member 23, and therefore, in the obtained functionally graded material, particularly, the electrode rod insertion hole 13 is used. A region having a locally different coefficient of thermal expansion is not formed on the bottom wall portion.

Various modifications can be made in the method for producing a functionally graded material of the present invention. For example, the shape of the space at the distal end of the external lead rod insertion hole 14 can be pointed. In this case, the tip of the upper hole forming member 24 may have a pointed shape. The entire lower hole forming member 23 may be made of a single material. For example, a heat-resistant core portion and a temporary sintering process formed on the outer peripheral surface of the core portion may be used. And a composite material composed of a surface layer portion made of a substance that evaporates and disappears due to heating in step (a). As the material of the core portion, for example, carbon black (graphite), a super-hard alloy, a high melting point metal such as hardened steel, and a heat-resistant material such as various ceramics can be used. In this case, the surface layer portion disappears,
The work of removing the core portion becomes easy.

FIG. 4 is an explanatory sectional view showing an example of the structure of the lamp sealing body of the present invention. This lamp sealing body 3
0 is the electrode rod insertion hole 13 obtained by the above method.
A sealing member 34 made of a functionally graded material 10 having an external lead rod insertion hole 14 is used. In particular,
In the electrode rod insertion hole 13 of the sealing member 34, the proximal end portion 32A of the electrode rod 32 in which the discharge electrode 31 is formed at the distal end is inserted and fixed, and the external lead rod insertion hole 14 is inserted. One end of the external lead rod 35 is inserted and fixed therein, and the electrode rod 32, the sealing member 34, and the external lead rod 35 are integrated.

The electrode rod 32 has, for example, an outer diameter of 0.4-4.
0mm tungsten wire, and its proximal end 32A
Is shaped to fit into the electrode rod insertion hole 13 of the functionally graded material 10, and the tip 32 B of the tip is basically the same as the tip 23 A of the lower hole forming member 23. Shaped, for example, conical. In this case, the opening angle of the top is in the range of 20 to 100 degrees, and preferably in the range of 30 to 60 degrees. The length of the conical portion is, for example, 0.6 mm. On the other hand, the outer lead rod 35 is made of, for example, a metal wire such as a tungsten wire or a molybdenum wire having an outer diameter of 0.3 to 3.0 mm.

The lamp sealing body of the present invention is manufactured as follows. That is, as described with reference to FIG. 2, the insulating inorganic material powder layer 25 located at one end,
Forming a powder laminate with a plurality of the mixed powder layers 26 laminated thereon to form a laminate molded body that is a pressure molded body,
This laminated molded body is temporarily sintered. In the preliminary sintering step, a heat treatment is performed on the laminated molded body in a non-oxidizing gas atmosphere at a maximum heating temperature of, for example, 1000 to 1200 ° C., thereby performing the same process as that shown in FIG. In addition, a sealed body which is a temporary sintered body in which a hole 13 for inserting an electrode rod and a hole 14 for inserting an external lead rod, each of which has a pointed space at its tip, are formed so as to extend in the axial direction from both end surfaces thereof. A material is formed.

The base portion 32A of the electrode rod 32 on which the discharge electrode 31 is formed at the distal end is inserted into the electrode rod insertion hole 13 of the sealing material, and the external lead rod insertion hole 14 is formed. The one end portion of the external lead rod 35 is inserted therein, and in this state, the material is heated at a temperature higher than the temperature in the above-described temporary sintering step, so that the main body of the sealing material is sintered. This main sintering process is performed in a non-oxidizing gas atmosphere or a reduced pressure atmosphere of, for example, 10 ⁻³ Pa or less, and the heating is performed, for example, under the condition that the maximum temperature is 1500 to 2000 ° C. As a result, the sealing body material, which was a temporarily sintered body, is finally made into a functionally gradient material made of a sintered body, and at the same time, as shown in FIG. The lamp sealing body 30 is manufactured, in which the electrode rod 32 and the external lead rod 35 are integrally fixed and connected to the member 34 by so-called shrink fitting.

In this lamp sealing body 30, the electrode rod 32
The distal end portion of the base side portion 32A of the functionally graded material constituting the sealing member 34 has a conductive inorganic substance component concentration of 2%.
It is desirably located in a layer portion of 0% by volume or more, preferably 40% by volume or more. Thereby, the electrode rod 32
The electrical connection between the sealing material 34 and the sealing material 34 is sufficient.

According to the lamp sealing body having such a structure, the electrode rod insertion hole 13 formed in the sealing member 34 is formed.
Since the shape of the distal end portion 13A is pointed, the proximal end portion 32A of the electrode rod 32 having the pointed distal end portion 32B that fits the tip portion 13A is inserted until it hits into the electrode rod insertion hole 13. Then, since the boundary surface between the two at the tip portion is inclined in the axial direction (length direction) of the electrode rod 32, the temperature distribution of the sealing member 34 in the direction is gently inclined, Therefore, occurrence of large thermal distortion is prevented.

Since the base portion 32A of the electrode rod 32 has a pointed tip portion 32B, the operation of inserting the base portion 32A into the electrode rod insertion hole 13 becomes extremely easy. . This is because the inner diameter of the electrode rod insertion hole 13 and the outer diameter of the electrode rod 32 are adapted to each other, and a lamp using a sealing body made of a functionally graded material is generally small. This is a great advantage in the actual working process.

Various changes can be made in the method of manufacturing a sealed body for a lamp of the present invention. For example, when the electrode rod is inserted into the electrode rod insertion hole 13 of the sealing member 34, the bottom of the electrode rod insertion hole 13 is filled with a small amount of a conductive inorganic substance powder, for example, a molybdenum powder that constitutes the functionally graded material. By doing so, it is possible to reliably prevent a gap from being formed between the tip of the inserted electrode rod 32 and the bottom wall surface of the electrode rod insertion hole 13. Can be tightly fixed. In this case, a local region of the conductive inorganic substance component is formed. However, since this region has high heat and electricity conductivity, there is no disadvantage due to the region, and rather, heat conduction is not caused. Due to the high property, the thermal strain generated in the functionally gradient material can be reduced.

FIG. 5 is an explanatory cross-sectional view showing another example of the structure of the lamp sealing body of the present invention. In this lamp sealing body 30, the electrode rod is composed of a large-diameter electrode rod portion 33A having a discharge electrode 31 formed at the distal end, followed by a small-diameter proximal portion 33B. The whole 33B is fixed in a state of being inserted into the electrode rod insertion hole 13 of the sealing member 34. Other configurations are the same as those in the example shown in FIG. In such a configuration, the outer diameter of the small-diameter proximal end portion 33B is one of the outer diameter of the large-diameter electrode rod portion 33A.
/ 2 or more. For example, when the outer diameter of the large-diameter electrode rod portion 33A is 0.4 to 4.0 mm, 0.2 to 0.2 mm
2.0 mm.

As in this example, by reducing the diameter of the base end portion of the electrode rod inserted into the sealing member 34,
The degree of thermal expansion of the base end portion caused by the change in temperature is reduced in absolute value, so that the stress generated in the sealing member 34 can be reduced, and the discharge electrode 3
A large heat capacity can be obtained in the large-diameter electrode rod portion 33A where the first electrode 1 is formed, and the stability of the temperature state of the discharge electrode 31 can be improved. As a result, the discharge state can be stabilized. Can be.

FIG. 6 is an explanatory sectional view showing still another example of the structure of the lamp sealing body of the present invention. In this lamp sealing body 30, the electrode rod is composed of a large-diameter electrode rod portion 33A having a discharge electrode 31 formed at the distal end, followed by a small-diameter proximal portion 33B. 33B
And a part of the large-diameter electrode rod portion 33 </ b> A following this is fixedly inserted in the electrode rod insertion hole 13 of the sealing member 34. Other configurations are the same as those in the example shown in FIG. Also in this example, the same operation and effect as the example of FIG. 5 can be obtained.

FIG. 7 is an explanatory cross-sectional view showing an example of a discharge lamp using the sealing body made of a functionally graded material according to the present invention. In this figure, 40 is an arc tube portion made of silica glass, 41 is a sealing body, 46 is a discharge electrode, and 43 is an electrode rod. The sealing body 41 has an insulating portion 44 at one end thereof.
And has a conductive portion 45 on the other end side,
Therefore, after the one end portion of the sealing body 41 is inserted into the sealing tube portion 42 of the arc tube portion 40, the sealing tube portion 42 is welded to the outer peripheral surface of the insulating portion 44 to form an airtight seal. Are formed. In this structure, the external lead rod 47
Thus, a path for introducing electricity to the electrode rod 43 and the discharge electrode 46 is formed via the conductive portion 45 of the functionally gradient material constituting the sealing body 41.

[0050]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described. Example 1 Molybdenum powder having a purity of 99.99% and an average particle size of 1.0 μm, and a purity of 99.99% and an average particle size of 5.6
Using silica powder of μm as a material powder, mixed powders having various conductive inorganic substance component concentrations were prepared. Further, to each of the constituent layer forming powders, stearic acid was added at a ratio of 5.0% by weight as a lubricant and a binder.

At the center of a bottom member of a mold having an inner space of 3.0 mm in inner diameter, a lower hole forming member having an outer diameter of 0.6 mm and a length of 11.0 mm made of a metal material constituting the mold is placed upward. It was fixed and provided in the state protruding. The lower hole forming member has a conical tip with an opening angle of about 60 degrees at the top. In this mold, silica powder or mixed powder is filled and laminated in ascending order of the conductive inorganic substance component concentration (molybdenum concentration), and a total of 1
A two-layer powder laminate was formed. On the other hand, the center of the lower surface of the pressing member has an outer diameter of 0.
An upper hole forming member having a length of 6 mm and a length of 3.0 mm is fixedly provided so as to protrude downward, and the pressing member is pressed against the upper surface of the powder laminate to further form the upper hole forming member. It was pushed inward from the uppermost layer, and the lower surface of the pressing member was brought into contact with the upper surface of the powder laminate.

From this state, the final pressure is 1.5 × 10 ⁸
The powder laminate is pressed in a state of Pa (1.5 ton / cm ² ), thereby forming a composite molded body in which the molded member for forming the lower hole and the molded member for forming the upper hole are joined to the laminated molded body. did. The outer diameter of this composite molding is 3.0 m
m and length were 15.0 mm.

The composite molded body was placed in a firing furnace and heated to about 1000 to 1200 ° C. in a hydrogen gas atmosphere to temporarily sinter the laminated molded body and to eliminate the binder added to the mixed powder. As a result, a cylindrical sealing material having external lead rod insertion holes and electrode rod insertion holes formed at both ends was obtained.

Next, one end of an external lead rod having an outer diameter of 0.5 mm and a length of 8.0 mm is inserted into the external lead rod insertion hole of this sealing material at an insertion depth of 3.0 mm. Inside the electrode rod insertion hole, a distal end portion has a discharge electrode formed by winding a tungsten wire having a diameter of 0.08 mm, and a base end portion has a substantially conical outer diameter of 0.6 mm with an opening angle of 60 degrees. After inserting the base end of an electrode rod having a length of 15.0 mm at an insertion depth of 10.0 mm, heating in a vacuum atmosphere of 10 ⁻³ Pa or less, and maintaining the temperature at about 1700 ° C. for about 10 minutes By cooling in a furnace and subjecting the pre-sintered body to the main sintering process, a sealed body for a lamp in which external lead rods and electrode rods extended from both ends of a columnar functionally graded material was manufactured. .

Using the lamp sealing body obtained as described above, the diameter of the luminous space in the luminous tube section was 11.0 mm, the distance in the tube axis direction was 11.0 mm, and the configuration shown in FIG.
The inner diameter of the sealing tube is 3.1 mm and the electrode tube distance is 1.5 mm
An ultra-high pressure mercury lamp with a rated lamp power of 100 W, in which 40 mg of mercury as a luminescent substance and 300 Torr of argon as a buffer gas were sealed.

The discharge lamp 30 manufactured as described above
When a continuous lighting test was performed on the book under rated lighting conditions, it was confirmed that stable discharge characteristics were obtained and a long service life was obtained in each case even when the lighting time exceeded 2000 hours. On the other hand, a discharge lamp was produced in exactly the same manner as above except that a tip having a flat end face was used as the lower hole forming molding member and the electrode rod, and a similar lighting test was performed. Five of them turned off before the lighting time reached 1000 hours. Then, when the functionally gradient material constituting the lamp sealing body was examined, it was confirmed that cracks occurred in the portion where the tip of the electrode rod was located.

Example 2 A sealing material was obtained in the same manner as in Example 1 except that a lower hole forming member made of polypropylene having an outer diameter of 0.3 mm and a length of 11.0 mm was used. Next, except that an electrode rod having an outer diameter of 0.6 mm and a large-diameter electrode rod having a length of 5 mm and an outer diameter of 0.3 mm and a small-diameter electrode rod having a length of 10 mm was used. A sealed body for a lamp was obtained in the same manner as in Example 1, and an ultra-high pressure mercury lamp was manufactured using the sealed body for a lamp.

The discharge lamp 30 manufactured as described above
When a continuous lighting test was performed on the book under rated lighting conditions, it was confirmed that stable discharge characteristics were obtained and a long service life was obtained in each case even when the lighting time exceeded 2000 hours.

Although the embodiment in which the present invention is embodied in a discharge lamp has been described in detail, the sealing body for a lamp made of the functionally graded material of the present invention is not limited to the discharge lamp, but the sealing structure in an incandescent lamp. It is also possible to apply to the formation of. In this case, a so-called internal lead rod is used in place of the electrode rod, and its base end portion is inserted and fixed in a lead rod insertion hole formed in the functionally graded material,
A filament coil may be connected to the tip of the tip portion.

[0060]

According to the functionally graded material of the present invention, since the tip of the hole that opens to the outer surface of the insulating inorganic material layer and extends in the laminating direction is pointed, the shape of the tip at the tip changes. It is gradual in the laminating direction of the functionally gradient material,
Therefore, since the change in the temperature distribution in the portion surrounding the tip of the hole is gradual, a large thermal stress does not occur locally.

In the method for producing a functionally graded material of the present invention, in the production of a functionally graded material by a dry method, a molding die on which a molding member for forming a hole having a pointed tip is used. A functionally graded material having desired performance can be manufactured without locally forming a region having a different coefficient of thermal expansion on the bottom wall of the hole. The tip of the hole forming member has a conical shape, and the opening angle of the vertex is 20 to 1.
When the angle is 00 degrees, the above-described operation and effect can be reliably obtained.

In the sealed body for a lamp according to the present invention, the tip of the base end portion of the lead rod inserted into the hole of the functionally gradient material has a sharp tip adapted to the shape of the hole of the functionally gradient material. Because of the head shape, the fixed state or the connection state of the two are tight, and the boundary surface between the two is inclined in the axial direction (length direction) of the lead rod. Even in the case where the temperature gradient changes, the temperature distribution in the portion surrounding the distal end portion of the base end portion of the lead rod is also moderate, so that a large thermal stress is not locally generated in the functionally gradient material.

Further, in the lamp sealing body of the present invention, the outer diameter of the base end portion of the lead rod inserted into the hole of the functionally gradient material is small, so that the thermal expansion due to its own temperature change is prevented. Since the degree is suppressed to be small, the stress generated in the functionally gradient material surrounding the base end portion can be reduced.

In the method for manufacturing a sealed body for a lamp according to the present invention,
The base end portion of the lead rod is inserted into the hole of the press-molded body manufactured by the above-described method, and in this state, the sintering process of the press-molded body is performed, whereby the inclined body formed of the sintered body is The lead rod is integrally fixed to the functional material, so that the lamp sealing body having the above-described effects can be advantageously and reliably manufactured.

In the lamp of the present invention, a thermally stable hermetic sealing structure is formed by the above-described lamp sealing body, so that stable operating characteristics can be obtained and the service life can be prolonged.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing an example of a configuration of a functionally gradient material of the present invention.

FIG. 2 is a cross-sectional view for explaining a method for producing a functionally gradient material according to the present invention.

FIG. 3 is a schematic diagram for explaining an example of a tip shape of a lower hole forming molding member used in a step of forming a powder laminate.

FIG. 4 is an explanatory cross-sectional view showing an example of the configuration of the lamp sealing body of the present invention.

FIG. 5 is an explanatory cross-sectional view showing another example of the configuration of the lamp sealing body of the present invention.

FIG. 6 is an explanatory sectional view showing still another example of the configuration of the lamp sealing body of the present invention.

FIG. 7 is an explanatory cross-sectional view showing an example of a configuration of a discharge lamp using the sealing body made of a functionally gradient material according to the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 Functionally graded material 11 Insulating inorganic material layer 12 Mixture layer 13 Electrode rod insertion hole 13A Tip 14 External lead rod insertion hole 20 Mold 21 Bottom member 22 Pressurizing member 23 Lower hole forming member 23A Tip 23a Cone-shaped tip 23b Bamboo spear-shaped tip 24 Molding member for forming upper hole 25 Insulating inorganic material powder layer 26 Mixed powder layer 30 Lamp sealing body 31 Discharge electrode 32 Electrode rod 32A Base part 32B Tip 33A Large diameter electrode Rod part 33B Small-diameter electrode rod part 34 Sealing member 35 External lead rod 40 Arc tube part 41 Sealing body 42 Sealing tube part 43 Electrode rod 44 Insulating part 45 Conductive part 46 Discharge electrode 47 External lead rod

 ──────────────────────────────────────────────────続 き Continuation of the front page F term (reference) 5C012 JJ01 5C043 AA13 AA14 CC02 DD11 EA01 EB18

Claims (7)

[Claims] An insulating inorganic material layer and a plurality of mixture layers each comprising a mixture of a conductive inorganic material component and an insulating inorganic material component are laminated, and each of the mixture layers is formed of the insulating inorganic material. In a laminate in which the proportion of the conductive inorganic material component increases stepwise from the one adjacent to the material layer, the space opens in the outer surface of the insulating inorganic material layer and extends in the stacking direction, and the tip has a pointed space. A functionally graded material, wherein a partitioning hole is formed. 2. An insulating inorganic material powder layer formed by filling an insulating inorganic material powder in a molding die having a rod-shaped hole forming member having a pointed tip end provided on a bottom surface thereof. Forming a plurality of mixed powders prepared by mixing the conductive inorganic material powder and the insulating inorganic material powder at a predetermined ratio, wherein the mixed ratio of the conductive inorganic material powder is different from that of the conductive inorganic material powder. By filling the mold in order from the one with the smaller proportion, on the insulating inorganic material powder layer, a plurality of mixed powder layers in which the proportion of the conductive inorganic material powder sequentially increases upward are laminated. Forming a pressure-molded body having holes by removing the hole-forming member after integrally forming the laminated powder layer by pressure-forming. Manufacturing method. 3. The method for producing a functionally graded material according to claim 2, wherein the tip of the hole forming molding member has a conical shape, and the opening angle of the top is 20 to 100 degrees. 4. A functionally graded material according to claim 1, comprising: a lead rod having a base end portion inserted into a hole of the functionally graded material and integrally fixed thereto. A sealing body for a lamp, wherein a tip portion of a base end portion has a pointed shape that matches a shape of a hole of the functionally graded material. 5. The sealing body for a lamp according to claim 4, wherein the lead rod has an outer diameter at a distal end portion protruding and extending from the functionally graded material, which is larger than an outer diameter at a proximal end portion. 6. A base portion of a lead rod is inserted into a hole of a press-formed body produced by the method according to claim 2 or 3, and in this state, firing of the press-formed body is performed. A method for manufacturing a sealed body for a lamp, characterized by obtaining a sealed body for a lamp in which a lead rod is integrally fixed to a functionally gradient material made of a sintered body by performing a sintering process. 7. A lamp, wherein a hermetic sealing structure is formed by the lamp sealing body according to claim 4.