JP3271601B2 - Electric introduction body for tube and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bulb electric introducer for closing a closed tube of a bulb such as a mercury lamp, a metal halide lamp, and a halogen lamp, and a method of manufacturing the same. The tube electrical introducer refers to a combined structure of a closed body and an electrode core.

[0002]

2. Description of the Related Art In a bulb, for example, a high-pressure discharge lamp, a pair of electrodes are opposed to each other in a spherical or elliptical spherical arc tube made of quartz glass, and a luminous metal such as mercury, a discharge gas and the like are sealed therein. A tubular blocking tube is connected to the end of the arc tube, and the electrode core bar having an electrode at the tip and an external lead bar are closed in a state where they are electrically connected by the blocking tube. Since the electrode rod and the closed tube made of quartz glass have significantly different coefficients of thermal expansion, the closed tube cannot be closed by welding directly to the electrode core.

For this reason, in the past, the closed pipe was closed by a foil sealing method or a step joining method of joining a plurality of glasses having different coefficients of thermal expansion, but recently, an insulating inorganic material component such as silica and molybdenum have been closed. Attention has been focused on closing an obstruction tube connected to an end of an arc tube with an obstruction body made of a functionally gradient material made of a conductive inorganic substance component such as that of FIG. In such closed bodies, one end is rich in an insulating inorganic material component such as silica, and the proportion of a conductive inorganic material component such as molybdenum increases continuously or stepwise toward the other end. Is what you do. Therefore, in the case of an obstruction made of a functionally gradient material molded of silica and molybdenum, the vicinity of one end of the obstruction contains a large amount of silica, is insulative, and has a thermal expansion coefficient of that of quartz glass. Near the other end, contains a large amount of molybdenum, is electrically conductive, and has a characteristic that the coefficient of thermal expansion is close to that of molybdenum.

[0004] In such an obstruction made of a functionally graded material, the gradient at which the ratio of the insulating inorganic substance component to the conductive inorganic substance component changes can be increased. In addition, it is possible to enrich the insulating inorganic substance component on one end face and enrich the conductive inorganic substance component on the other end face. In addition, since the functionally graded material does not have a boundary surface where the composition of the constituents changes greatly, heat shock and mechanical strength are strong. Therefore, the sealing portion for welding the closing body to the closing tube can be brought close to the central portion of the arc tube, which becomes hot at the time of lighting, and the length of the closing tube in the axial direction is short. It has the advantage that it can be shortened.

[0005]

When a closed body is formed from a functionally gradient material comprising a conductive inorganic material component and an insulating inorganic material component, first, a binder is added to these powders and pressed in a mold. To obtain a columnar pressure-formed body. Then, the press-formed body is pre-sintered at a temperature of about 1300 ° C. to obtain a pre-sintered body. Next, a hole for embedding an electrode core rod in the axis of the temporary sintered body is formed to form a center hole. Alternatively, it is pressed in a mold having a protruding member for forming a center hole to obtain a press-formed body in which a center hole is formed in advance, and this is temporarily sintered. Then, after inserting the electrode core rod into the center hole of the temporary sintered body, main sintering is performed at a temperature of about 1750 ° C.

When sintering functionally graded materials, these materials shrink by as much as 10 to 20%. Therefore, the center hole of the pre-sintered body needs to be larger than the outer diameter of the electrode rod. There is. At this time, if the size of the center hole is insufficient, stress is generated in the functionally graded material around the electrode core rod during the main sintering and cracks, so the center hole is slightly larger than a predetermined value, It is necessary to prevent cracks from occurring even if the functionally graded material shrinks by the main sintering.

In this case, the electrode core rod is not sufficiently and stably adhered to the closing member due to a variation in the diameter of the center hole or a variation in shrinkage during the main sintering. In the case of a through hole penetrating to the other end face, there is a problem that the airtightness becomes insufficient. For this reason, after the main sintering, a glass or a metal braze is welded to the exposed side surface of the closing member from which the electrode core rod extends to prevent leakage and secure the fixing between the closing member and the electrode core rod. , The number of steps increased, and the production took time.

In the case where the center hole is a non-through hole formed at a predetermined distance from the end face of the closing body, the problem of leakage does not occur, but the fixing is insufficient. There were problems such as falling off. Therefore, also in this case, after the sintering, it is necessary to take some means for ensuring the fixing of the closing member and the electrode core rod.

Therefore, according to the present invention, the electrode core rod is securely fixed by sintering in the central hole of the closed body composed of the conductive inorganic substance component and the insulating inorganic substance component, and the leak and the electrode core rod fall off. It is an object of the present invention to provide a tube electric introducer and a method for producing the same without any trouble.

[0010]

In order to achieve the above object, a first aspect of the present invention is a tube electric introducer for sealing a closed tube connected to an arc tube of a tube, comprising: An electrode core rod is inserted through a center hole formed in a sintered functionally graded material formed of a columnar structure having a multi-layered structure composed of an inorganic material component and an insulating inorganic material component, and the ratio of both is sequentially changed along the axial direction. In the closed body for a tube, the conductive inorganic material component of the closed body, the metal component of the electrode core, and the sintering temperature of the functionally graded material are closed at the boundary region between the closed body and the electrode core. A diffusion region of the diffusion promoter, which promotes the diffusion of the conductive inorganic substance component of the body and the metal component of the electrode core rod, is formed by diffusion of the three components into each other. It is intended to be a tube electric introducer in which the inner surface of the hole is joined.

In the present application, the diffusion promoter is a solid solution in both the metal component of the electrode core rod and the conductive inorganic substance component of the plug at the sintering temperature of the functionally gradient material constituting the plug, and A substance that promotes mutual diffusion between the inorganic substance component and the conductive inorganic substance component of the closing body.

[0012] Such a closed body for a bulb can be suitably manufactured by the invention of the second, third or fourth aspect.

[0013]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 shows a xenon short-arc lamp having a rated power of 3 kW, which is shown as an example of a high-pressure discharge lamp using the electric tube guide of the present invention. In addition, the electricity introducing body for a bulb of the present invention can be applied to other discharge lamps such as a mercury lamp and a metal halide lamp as a discharge lamp.

In the embodiment of the present invention, an example is described in which the lamp tube is used for a discharge lamp, but the present invention can also be used for an incandescent lamp such as a halogen lamp having a tungsten filament. In the discharge lamp, the electrode rod is fixed to the center hole of the closed body by sintering.However, when using the bulb electric introducer of the present invention for a halogen lamp having a tungsten filament, it is not an electrode rod. The inner lead rod used at the tip connected to the end of the tungsten filament is fixed by sintering in the center hole of the closing body.

In FIG. 1, an arc tube 11 made of quartz glass is shown.
Has a spherical or elliptical central portion, in which an anode 20 and a cathode 30 made of tungsten are opposed to each other at intervals of, for example, 5 mm. Xenon gas is sealed at a predetermined pressure as a discharge gas.
Closed tubes 12, 12 are connected to both ends of the arc tube 11, and the ends of the closed tubes 12, 12 are made of a functionally graded material made of a conductive inorganic material component and an insulating inorganic material component. It is closed by a tube electrical introducer 70 composed of the body 50 and the electrode core 40.

The closing body 50 is fitted into the closing tube 12 such that the insulating end face 51 faces the arc tube 11, and the end face 51 is welded to the quartz glass closing tube 12. The electrode rod 40 of the anode 20 and the electrode rod 40 of the cathode 30 are made of tungsten, and the insulating end face 51 of the closing body 50 is made of, for example, almost 100% silica.
The conductive end face 52 has a composition of 25% SiO ₂ + 75% Mo.

The functionally gradient material consisting of silica and molybdenum is sintered at about 1750 ° C., but the electrode core 40 is coated with a diffusion promoter or the plug 50 is formed of a functionally graded material. By including a diffusion promoter,
At the sintering temperature, the diffusion promoter forms a solid solution with the conductive inorganic substance constituting the closing body 50 and melts. The molten solid solution diffuses into the metal component of the electrode core 40, and the closed body 5
The interdiffusion region of the conductive inorganic material component, the diffusion promoter, and the metal component of the electrode core bar 40 constituting the electrode core bar 40 is
The electrode core bar 40 and the inner surface of the center hole of the closing member 50 are securely bonded and fixed to each other in the interface region between the electrode core 40 and the inner surface of the closing member 50.

Therefore, the high-pressure gas in the arc tube 11 leaks from between the electrode core rod 40 and the closing member 50, or the electrode core rod 4
0 does not fall off, and the reliability of the joint is improved. Therefore, unlike the related art, there is no need to weld glass or metal braze to the end face 52 of the closing body 50 from which the electrode core bar 40 extends, and the process can be simplified.

Alternatively, as shown in FIG. 2, non-penetrating center holes are formed from both end surfaces 51 and 52 of the closing body 50 to portions having electrical conductivity, respectively, and the anode 20 and the cathode 30 are formed in the respective center holes. The electrode core bar 40 and each of the anode terminal 22 and the cathode terminal 32 may be electrically connected.
Also in this case, the electrode core 40 is coated with a diffusion promoter,
Alternatively, the diffusion promoter provided by including the diffusion promoter in the closing body 50 formed of the functionally gradient material forms a solid solution with the conductive inorganic substance component constituting the closing body 50 and is melted. An interdiffusion region between the conductive inorganic substance component, the diffusion promoter, and the metal component of the electrode core bar 40 constituting the body 50 is formed in an interface region between the electrode core bar 40 and the inner surface of the center hole of the closing body 50, and the electrode core is formed. The rod 40 and the inner surface of the center hole of the closing body 50 are securely joined and fixed.

Next, an embodiment of the invention according to claim 2 which is a method for producing the electric bulb introduction device according to claim 1 will be described. The conductive inorganic substance component and the insulating inorganic substance component of the functionally gradient material are, for example, molybdenum powder having an average particle diameter of 1.0 μm and silica powder having an average particle diameter of 5.6 μm. First, as a first step, a plurality of powder mixtures in which the mixing ratio of molybdenum powder and silica powder is changed is prepared.

The insulating inorganic substance component of the functionally gradient material may be the same substance as the arc tube, such as using the ceramic powder when the arc tube is made of ceramic, in addition to the silica powder described above. Of course, as the conductive inorganic substance component of the functionally graded material, other than the molybdenum powder, an appropriate metal conductive substance powder such as nickel and tungsten can be used.

In a second step, the mixed powder is mixed with an organic binder, for example, a solution of about 23% of stearic acid and dried. Then, this mixture is filled into a cylindrical mold having a protruding member for the center hole. In the case of a functionally graded material, the powder mixture is molded so that the mixing ratio of molybdenum powder and silica powder changes sequentially. Fill. Then, pressure is applied from the outside of the cylindrical mold with, for example, a load of 1.5 t / cm ² to obtain a columnar press-formed body having a center hole formed therein.

Further, as a third step, the obtained pressed body is sintered in a hydrogen atmosphere at 1200 ° C. for 30 minutes.
The organic binder is removed to obtain a temporarily sintered body.

Next, as a fourth step, the surface of the electrode rod is
For example, a chromium layer is formed as a diffusion promoter. The chromium layer is formed by a plating method, a powder dipping method, a sputtering method, or the like. For example, the thickness of the chromium layer may be about 30 μm. Chromium is, for example, both tungsten selected as the electrode core rod and molybdenum selected as the conductive inorganic substance component of the functionally graded material, a metal that forms a solid solution at a sintering temperature of 1750 ° C.
It is effective as a diffusion promoter.

The diffusion promoter is not limited to chromium, but diffuses at the sintering temperature into both the electrode core and the conductive inorganic material component of the plug, thereby simultaneously forming the metal component of the electrode core. Promotes interdiffusion between the electrode and the conductive inorganic material component of the closing member, and an interdiffusion region is formed in an interface region between the electrode core and the closing member, so that the electrode core and the closing member are securely joined and fixed. Anything should do.

At a main sintering temperature of 1750 ° C., at least 5 at% of an element selected as a diffusion promoter is dissolved in molybdenum, which is a conductive inorganic substance component of the plug, and tungsten, which is a metal component of the electrode rod. Further, since the melting point is lower than that of molybdenum and tungsten, which are the main conductive inorganic substance components of the conductive inorganic substance component and the electrode core rod, the metal has a large diffusion length into them.

For example, if molybdenum is taken as an example of the conductive inorganic material component constituting the closing member, the diffusion promoter may be Cr, Al, Co, Fe, Ni, Hf, Ir, N
b, Os, Pt, Pd, Ru, Rh, Si, Ti, V,
A single metal such as Ta, Zr, and Re, or an alloy thereof can be used.

As a fifth step, an electrode core bar 40 having a diffusion accelerator layer formed on the surface thereof is inserted into the center hole of the temporary sintered body. That is, as shown in FIG. 3, the diffusion promoter 60 is interposed between the inner peripheral surface of the center hole of the closing body 50 and the outer peripheral surface of the electrode core 40.

Then, in a non-oxidizing atmosphere or a vacuum state of about 10 ⁻² Pa, sintering is performed at 1750 ° C. for 10 minutes to perform main sintering. Among them, chromium is determined from the chromium-molybdenum-based and chromium-tungsten-based phase diagrams,
At a temperature of 77 ° C. or higher, the solid solution forms a solid solution in both molybdenum and tungsten. As long as the cooling rate is substantially faster,
Since the solid solution state is maintained even at lower temperatures, cavities (nests) are not formed. Further, since the sintering temperature of 1750 ° C. is close to the melting point of chromium, the diffusion coefficients of tungsten and molybdenum in chromium are very large.

Therefore, the sintering temperature is maintained for a certain time,
After being cooled, the chromium of the diffusion promoter 60 shown in FIG. 3 contains the plug 50 as shown in FIG.
Of molybdenum and tungsten of the electrode rod 40,
At the same time, the molybdenum of the closing body 50 is
And the tungsten of the metal component of the electrode core 40 also diffuses into the chromium of the diffusion promoter 60 and the molybdenum of the plug 50. As a result, molybdenum as the conductive inorganic substance component and tungsten as the metal component of the electrode core rod are in a state where they are well diffused with each other, so that a well-bonded closed body can be obtained.

Chromium, which is a diffusion promoter, forms a solid solution with molybdenum, which is a conductive inorganic material component constituting the closing body 50, and is melted.
Flow into and diffuse into the tungsten constituting
Thus, an interdiffusion region of molybdenum as a conductive inorganic material component, chromium as a diffusion promoter, and tungsten of the electrode core 40 is formed, and the electrode core 40 and the closing member 50 are joined.

An experimental example for confirming the effect of the present invention will be described below. 15% by weight of silica and 85% by weight of molybdenum are homogeneously mixed, molded into a columnar shape, and provided with a through-hole at the center thereof. Introductory samples were prepared. Then, a sample obtained by sintering the sample at 1750 ° C. for 10 minutes in a vacuum atmosphere is
Cut out in the axial section including the tungsten core rod,
The cut surface was analyzed by EDX (energy dispersive X-ray spectroscopy).

FIG. 5 shows the result of EDX analysis. As can be seen from the figure, tungsten (W) of the tungsten core rod and molybdenum (Mo), which is a conductive inorganic substance component of the closing body, diffuse and join with each other in the diffusion region, and the tungsten core rod and the closing body are closed. The inner surface of the center hole was securely fixed. Tungsten and molybdenum mutually diffused by 10 μm or more in the chromium-plated portion. FIG.
As shown in the figure, chromium also diffused about 10 μm on the core rod side and about 100 μm on the closed body side. Observation was also made with an electron microscope image, and it was confirmed that the boundary between the tungsten core rod and the closing body had disappeared and that the tungsten core rod was securely fixed.

For comparison, the core rod and the closing member were joined under the same conditions as when chromium plating was applied, without chromium plating. FIG. 4 shows the EDX analysis result at that time. As is clear from FIG. 4, when chromium plating is not performed, that is, when there is no diffusion accelerator, mutual diffusion of both tungsten and molybdenum is hardly observed.

According to the second aspect of the present invention, a press-formed body having a center hole is obtained by using a cylindrical mold having a projecting member for the center hole. The outer peripheral surface of the core rod 40 is coated with a diffusion promoter, and then the electrode core rod 40 is erected at the center of a cylindrical mold, and a powder mixture mixed with an organic binder is filled in the cylindrical mold. Then, pressure is applied from the outside of the cylindrical mold to obtain a press-molded body integrated with the electrode core rod 40.

Next, a fourth embodiment of the invention will be described. A plurality of first powder mixtures are prepared by mixing a conductive inorganic substance component, for example, molybdenum powder, and an insulating inorganic substance component, for example, silica powder, so that the proportions thereof are different. Then, one or more of the first powder mixture is mixed with, for example, nickel powder as a diffusion promoter, for example, at a volume ratio of 5% to obtain a second powder mixture.

Next, the first powder mixture and the second powder mixture are individually mixed with an organic binder, and the ratios of the molybdenum powder and the silica powder are sequentially changed in a cylindrical mold having a protruding member for a central hole. The first powder mixture is filled, then the second powder mixture is filled, and then the first powder mixture is similarly filled so that the ratios of the molybdenum powder and the silica powder are sequentially different to form a powder laminate. Pressure is applied from the outside of the mold to obtain a press-formed body composed of a multilayer body.

FIG. 7 shows an example of the mixing ratio (wt%) of each powder and the thickness of each layer.

The pressed compact is pre-sintered into a pre-sintered body. Next, an electrode core 40 is inserted into the center hole of the pre-sintered body (obtained in the fourth step as a fifth step). Insert and fully sinter.
When the functionally graded material having the mixing ratio shown in FIG. 7 was used,
As shown in FIG. 9, the closing body 50 is composed of 12 layers,
The layer is silica only, the second to eighth layers and the twelfth layer are a mixture of silica and molybdenum, which are formed from the first powder mixture.

On the other hand, the ninth to eleventh layers are a mixture of silica, molybdenum and nickel, which are formed from the second powder mixture. Although the thicknesses of the respective layers are not the same as shown in FIG. 7, they are drawn to the same thickness in FIG. 9 for convenience. Then, the pre-sintered body is sintered at 1750 ° C. for 10 minutes in a non-oxidizing atmosphere or a vacuum state of about 10 ⁻² Pa for main sintering.

By the main sintering, nickel contained in the ninth to eleventh layers forms a solid solution with molybdenum constituting the closing body 50 and diffuses toward the electrode core rod 40 to form an interdiffusion region of tungsten, molybdenum and nickel. Are formed and joined.

In this case, the same result as in FIG. 5 can be obtained in the EDX analysis. That is, the tungsten and the molybdenum of the tungsten core rod are mutually diffused and joined in the diffusion region, and the electrode core rod 40 and the inner surface of the center hole of the closing body 50 are securely fixed. This is due to the diffusion promoting action of nickel. In addition, observation was also made with an electron microscope image. In this case, too, it was confirmed that the boundary between the electrode core bar 40 and the closing body 50 was eliminated, and that the electrode core rod 40 was securely fixed.
Therefore, the high-pressure gas does not leak from the boundary between the electrode core bar 40 and the closing body 50 during lighting.

Although the mixing ratio of nickel to molybdenum in FIG. 7 is 5 wt%, the mixing ratio of nickel to molybdenum was changed, and the mixing ratio and the occurrence rate of leakage were examined. FIG. 8 shows the result. As can be seen, the mixing ratio of nickel was 5 wt% and 1 wt%.
In the case of 0 wt%, no leakage was observed, but when the mixing ratio of nickel was 3 wt% and 20 wt%, the probability of leakage increased.

This is because when the mixing ratio of nickel is 3 wt%, the amount of nickel is too small to form a sufficient interdiffusion region. Further, when the mixing ratio of nickel is 20 wt%, nickel and molybdenum are 1
Although the solid solubility limit at 750 ° C. is large, excessive molybdenum or nickel precipitates or forms a third phase in the cooling process, so that vacancies are left in the alloy, and leaks from these vacancies. It is.

In the fourth aspect of the present invention, a press-formed body having a center hole is obtained by using a cylindrical mold having a projecting member for the center hole. The first powder mixture and the second powder mixture, which are erected at the center of the cylindrical mold and mixed with an organic binder, are sequentially filled in a cylindrical mold,
It is also possible to apply pressure from the outside of the cylindrical mold to obtain a pressed molded body integrated with the electrode core bar 40.

In the above, the embodiment of the invention according to claim 4 has been described for the case where nickel is used as a diffusion promoter, but the case where chromium is used as a diffusion promoter is as follows.

A plurality of first powder mixtures are prepared by mixing a conductive inorganic substance component, for example, molybdenum powder, and an insulating inorganic substance component, for example, silica powder, so that the proportions thereof are different. Then, one or more of the first powder mixture is mixed with, for example, 5% by volume of chromium powder as a diffusion promoter in a volume ratio to obtain a second powder mixture.

Next, the first powder mixture and the second powder mixture are individually mixed with an organic binder, and the cylindrical mold is filled with the first powder mixture so that the ratios of the molybdenum powder and the silica powder are sequentially different. Then, the second powder mixture is filled, and then the first powder mixture is filled into a powder laminate so that the ratios of the molybdenum powder and the silica powder are sequentially different from each other. Pressing is performed to obtain a pressure-formed body composed of a multilayer body.

FIG. 10 shows an example of the mixing ratio (wt%) of each powder and the thickness of each layer.

The pressed compact is pre-sintered into a pre-sintered body, and the electrode core 40 is inserted into the center hole of the pre-sintered body. FIG.
When a functionally graded material having a mixing ratio of 0 was used, the closing body 50 was composed of 12 layers, the first layer was silica only, and the second layer was not.
The eighth to twelfth layers are a mixture of silica and molybdenum, which are formed from the first powder mixture.

On the other hand, the ninth to eleventh layers are a mixture of silica, molybdenum and chromium.
It was formed from a powder mixture. Then, the pre-sintered body is sintered at 1750 ° C. for 10 minutes in a non-oxidizing atmosphere or a vacuum state of about 10 ⁻² Pa for main sintering.

By the main sintering, the chromium contained in the ninth to eleventh layers forms a solid solution with molybdenum constituting the closing body 50 and diffuses toward the electrode core 40 side, and an interdiffusion region of tungsten, molybdenum and chromium. Are formed and joined. In this case, the same result as in FIG. 5 was obtained in the EDX analysis. That is, the tungsten and the molybdenum of the tungsten core rod are mutually diffused and joined in the diffusion region, and the electrode core rod 40 and the inner surface of the center hole of the closing body 50 are securely fixed. This is due to the diffusion promoting action of chromium.

In addition, observation was also made with an electron microscope image. In this case, too, it was confirmed that the boundary between the electrode core bar 40 and the closing member 50 was lost, and that the electrode core rod 40 was securely fixed.
Therefore, the high-pressure gas does not leak from the boundary between the electrode core bar 40 and the closing body 50 during lighting.

[0054]

As described above, according to the present invention, the interface region between the inner peripheral surface of the center hole of the closure body made of a functionally gradient material composed of the conductive inorganic material component and the insulating inorganic material component and the outer peripheral surface of the electrode core rod is provided. In addition, an interdiffusion region was formed between the conductive inorganic material component, the insulating inorganic material component, and the diffusion promoter, so that the electrode core rod and the conductive inorganic material component of the closing member were joined. The inner surface of the hole and the electrode core rod are securely fixed, so that there is no leakage or the electrode core rod falling off, and it is possible to obtain a tube electric introducer in which the reliability of the joint portion of the electrode core rod is greatly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a high-pressure discharge lamp in which a closing portion of a light emitting tube is closed with a tube electrical introducer in which an electrode core is penetrated and held by a closing member formed of a functionally graded material.

FIG. 2 is an explanatory view of another high-pressure discharge lamp in which a closing portion of a light emitting tube is closed with a tube electrical introducer in which an electrode core is held in a closed body formed of a functionally gradient material without penetrating the electrode core rod.

FIG. 3 is an explanatory diagram of a main part according to claim 2;

FIG. 4 shows the results of EDX analysis of the electrode core joint of the closed body in the case where the diffusion promoter is not used in the conventional example.

FIG. 5 shows the results of EDX analysis of the electrode core rod joint of the closed body in the case where a diffusion promoter is used in the example of the present application.

FIG. 6 shows the results of EDX analysis of the electrode core rod joint of the closed body in the case of using the diffusion promoter in the example of the present application.

FIG. 7 is a table showing an example of a mixing ratio (wt%) of each powder and a thickness (mm) of each layer in the case where the diffusion promoter is nickel.

FIG. 8 shows the mixing ratio (wt%) of each powder and the probability of occurrence of leakage.

FIG. 9 is an explanatory diagram of a main part of claim 4;

FIG. 10 is a table showing an example of the mixing ratio (wt%) of each powder and the thickness (mm) of each layer in the case where the diffusion promoter is chromium.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Arc tube 12 Closure tube 20 Anode 30 Cathode 40 Electrode core bar 50 Closure body 60 Diffusion promoter 70 Electric introduction body for tube

──────────────────────────────────────────────────続 き Continuing on the front page (72) Kamazo Kai Kai 1194, Sado, Bessho-cho, Himeji-shi, Hyogo Ushio Electric Co., Ltd. Inside Electric Co., Ltd. (72) Inventor Shigenori Nozawa 1194 Sado, Bessho-cho, Himeji-shi, Hyogo Ushio Electric Co., Ltd.Examiner Shinichi Mukogo (56) References JP-A-10-40868 (JP, A) JP Hei 8-138555 (JP, A) JP-A Hei 10-144262 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 61/36 H01J 9/24

Claims (4)

(57) [Claims] 1. A bulb electric introducer for sealing a closed tube connected to an arc tube of a bulb, comprising a conductive inorganic material component and an insulating inorganic material component, and extending along an axial direction. The electrode introducer for a bulb, wherein an electrode core rod is inserted through a center hole formed in a closed body, which is made of a functionally graded material formed into a substantially columnar shape having a multilayer structure in which the ratio of both is sequentially changed. In a boundary region between the body and the electrode core, a conductive inorganic material component constituting the closing body, a metal component of the electrode core, and a conductive forming the closing body at a sintering temperature of the functionally graded material. A diffusion region of the diffusion promoter, which promotes the diffusion of the inorganic substance component and the metal component of the electrode core rod, has been formed in which the three components have mutually diffused, and the inner surface of the electrode core rod and the central hole of the closing body are formed. An electric bulb insert for a tube, characterized by being joined. 2. The method for producing a tube electrical introducer according to claim 1, wherein the method comprises the following steps. (1) A first step of preparing a powder mixture in which a conductive inorganic substance component powder and an insulating inorganic substance component powder are mixed. (2) The powder mixture prepared in the first step is mixed with an organic binder, filled into a cylindrical mold having a protruding member for a central hole, and pressurized from outside the cylindrical mold. The second step of obtaining a molded body. (3) A third step of temporarily sintering the pressure-formed body to obtain a temporarily sintered body. (4) A fourth step of coating the outer peripheral surface of the electrode core with a diffusion promoter. (5) The electrode core rod obtained in the fourth step is inserted into the center hole of the temporary sintered body obtained in the third step, the temporary sintered body is fully sintered, and the electrode core rod and the main body are sintered. Fifth joining the inner surface of the center hole of the body
Process. 3. The method for producing a tube electric introducer according to claim 1, wherein the method comprises the following steps. (1) A first step of preparing a powder mixture in which a conductive inorganic substance component powder and an insulating inorganic substance component powder are mixed. (2) A second step of coating the outer peripheral surface of the electrode rod with a diffusion promoter. (3) The electrode core rod obtained in the second step is erected at the center of a cylindrical mold, and the powder mixture prepared in the first step is mixed with an organic binder and filled in a cylindrical mold. And a third step of obtaining a press-molded body by applying pressure from the outside of the cylindrical mold. (4) A fourth step of temporarily sintering the pressure-formed body to obtain a temporarily sintered body. (5) A fifth step of main-sintering the pre-sintered body obtained in the fourth step and joining the electrode core rod and the inner surface of the center hole of the sintered body. 4. The method according to claim 2, wherein, instead of coating the outer peripheral surface of the electrode core with the diffusion promoter, the conductive inorganic material is used in the first step. A production method, comprising mixing a component powder and an insulating inorganic substance component powder, and mixing a diffusion promoter therein.