TW201530607A - Short-arc discharge lamp and short-arc discharge lamp cathode production method - Google Patents

Abstract

Provided are a short-arc discharge lamp allowing an anticipated light-starting ability to be obtained stably, and a discharge lamp cathode production method. The short-arc discharge lamp is provided with a cathode formed by joining a plurality of cathode-forming materials, constituted in such a way that one cathode-forming material containing an emitter substance, and another cathode-forming material to be joined with the cathode-forming material are joined by melting a joining material, which is interposed between the cathode-forming materials, by electrifying each of the cathode-forming materials.

Description

Method for manufacturing cathode for short arc type discharge lamp and short arc type discharge lamp

The present invention relates to a method for producing a cathode for a short arc type discharge lamp and a short arc type discharge lamp. In particular, there is a short arc type discharge lamp including a cathode including a substance to be discharged at a distal end side portion, and a method of manufacturing the cathode.

A short arc type discharge lamp (hereinafter also referred to simply as a "discharge lamp") is similar to a point light source, and is used as a light source of an exposure apparatus having a high light collection efficiency by being combined with an optical system. .

Further, a short arc type discharge lamp in which a crucible is enclosed is used as a light source such as a projector.

In the prior art, in the cathode of such a discharge lamp, in order to improve the startability of lighting, a material called a discharge material which lowers the work function is added. The release substance contained in the cathode is a long-term use of a ruthenium compound from the viewpoint of excellent contribution to startability (refer to Patent Document 1). However, lanthanide is a substance with strong radiation, which is caused by restrictions on radioactive substances in recent years, and there is a limit on the amount of input and output. Therefore, in a relatively large discharge lamp, I want It is difficult to contain a single thing in the entire cathode.

Therefore, in Patent Document 2, there is disclosed a structure in which a crucible is contained only in the front end portion of the cathode, that is, a structure in which a crucible is partially contained only at a necessary place is disclosed. The cathode is a cathode formed material made of tungsten containing tantalum and a cathode formed of tantalum containing no tantalum, and is formed by diffusion bonding. Constitute.

In the cathode provided with such a main body portion, a sufficiently high mechanical strength can be obtained at the joint portion, and even in the temperature condition of the lighting of the discharge lamp, for example, at 2000 to 2400 ° C, the image can be avoided. It is a problem that the end portion of the cathode is detached.

However, in the above-described general method for manufacturing a cathode, in order to bond the cathode forming material, it is a special device requiring a vacuum device, a heating device, a pressurizing device, etc., and it is extremely expensive in such a device. The problem of cost.

Further, in the joining process, it takes time in the processes of vacuum processing, heat treatment, cooling treatment, etc., which also causes problems. Further, there is also a problem that the manufacturing cost is high due to the long manufacturing time.

Further, as described above, since the enamel is a radiating element, careful consideration is required in the management and handling of the bismuth compound.

In view of such a situation, recently, as a substance to be released, a cathode containing a non-radiative rare metal compound or a ruthenium compound such as lanthanum oxide (La ₂ O ₃ ) or hafnium oxide (HfO ₂ ) has been proposed (refer to the patent). Document 3).

However, when a cathode containing a rare metal compound or a cerium compound is used as a releasing substance, there are the following general problems.

In the cathode of the discharge lamp, the evolved substance which contributes to the electron radiation characteristics is present only at the front end portion of the cathode. Here, the discharged substance existing at the end side portion of the cathode is evaporated when the discharge lamp is lit, and the front end side portion of the cathode is heated, but by ejecting the substance from the rear end of the cathode The front end moves, and the end side portion is supplemented with the evolved substance before the cathode.

However, the substance which is formed from a rare metal compound or a ruthenium compound is more likely to evaporate when the discharge lamp is lighted than the substance released from the ruthenium compound. On the other hand, if the evaporation rate of the discharged material at the end portion before the cathode is faster than the movement of the evolved substance from the rear end of the cathode toward the front end, the material released at the end side portion of the cathode is depleted early. Therefore, in a discharge lamp which uses a substance other than a bismuth compound as a substance to be discharged contained in the cathode, there is still a problem that the lighting state may become unstable at an early stage.

In particular, in a high-input discharge lamp of 1 kW or more, the evaporation system of a rare metal compound or a cerium compound is remarkable, and the lighting state is remarkably unstable at an early stage.

Therefore, the inventors of the present invention have produced a rare metal compound or a ruthenium compound which is contained in a high concentration in the cathode. The cathode of the form of the released material of the released material. In order to dispose the discharge material inside the cathode, it is necessary to form a recess in the body portion. Therefore, the main body portion is cut or the like to form a concave portion, and the discharge material is placed in the concave portion, and then the cutting surface is joined. In such a joining process, it is difficult to hermetically join the joint faces, and a slight gap is formed between the joint faces. When the discharge lamp produced in such a manner is turned on, the discharged material is easily evaporated due to the fact that the vapor pressure is high, so that the following general problem occurs: that is, the discharged matter is from the joint surface to each other. A slight gap between them becomes a liquid or vapor and is ejected to the outside.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 11-96965

[Patent Document 2] Japanese Laid-Open Patent Publication No. 2012-190627

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2005-519435

It is an object of the present invention to provide a short arc type discharge lamp which is capable of partially containing a cathode which emits a substance at a necessary portion, and is configured to be maintained even at a high temperature in a lamp lighting If the mechanical strength is sufficiently high, the desired lighting startability can be stably obtained.

Another object of the present invention is to provide a short arc type discharge lamp which, even if the substance contained in the cathode is a substance other than a bismuth compound, does not cause the discharged substance to be ejected to External, and can cover a long period of time to achieve a stable lighting state.

Still another object of the present invention is to provide a method for producing a cathode which can be produced in a short time by a simple method to partially contain a release substance and even if it is A cathode capable of maintaining a sufficiently high mechanical strength at a high temperature in the lamp lighting.

The short arc type discharge lamp of the present invention is a short arc type discharge lamp in which a cathode and an anode having a substance to be discharged are disposed opposite to each other in a front end side portion, and the cathode is a cathode. Forming a plurality of cathode forming materials by bonding, and a cathode forming material containing one of the discharged materials and another cathode forming material bonded to the cathode forming material are formed by the cathode forming materials. Each of the electrodes is energized, and the bonding material interposed between each of the cathode forming materials is melted to bond.

In the short arc type discharge lamp of the present invention, it is preferable that a sealed space surrounded by one of the cathode forming materials and the other cathode forming material is provided inside the cathode, and the sealed space is provided in the sealed space. The material is arranged to contain a release material that does not contain the released material of the crucible.

In the short arc type discharge lamp of the present invention, it can be set as follows In a general configuration, the cathode includes a body portion including a body portion and a front end portion continuous to an end surface of the body portion, and one of the cathode forming materials and the body In order to form the front end portion forming material of the front end portion, the other cathode forming material is a body portion forming material constituting the body portion, and the body member is provided to extend along the axial direction and at the front end side of the cathode Further, the recessed portion having the opening, the end surface of the annular body forming member and the end surface of the front end portion forming material are joined via the bonding material.

In the short arc type discharge lamp of the present invention, the cathode may be configured to include a main body portion and an electrode shaft portion for holding the main body portion, and one of the cathodes The formed material is a body portion forming material constituting the main body portion, and the other cathode forming material is a core rod member constituting the electrode shaft portion, and the body portion forming material is provided to extend along the axial direction and a first recess having an opening at a rear end side of the cathode, and a second recess extending in the axial direction and extending to an inner diameter smaller than an inner diameter of the first recess, the body is continuous with the first recess The annular bottom surface of the first concave portion of the portion forming material and the front end surface of the mandrel member are joined via the bonding material.

In the short arc type discharge lamp of the present invention, it is possible to adopt a general configuration in which the bonding material is the same as the cathode forming material or the other cathode forming material. The material is formed integrally with at least one of the cathode forming material and the other cathode forming material.

In the short arc type discharge lamp of the present invention, it can be set as follows In general, the bonding material is selected from the group consisting of tantalum (Ta), niobium (Nb), molybdenum (Mo), hafnium (Hf), niobium (Re), and alloys thereof.

The method for producing a cathode according to the present invention is a method for producing a cathode containing a substance to be discharged in a distal end side portion, and is characterized in that: a cathode forming material containing one of the released substances, and a cathode formed thereon The other cathode forming material at the cathode forming material is disposed such that a bonding material is interposed between the joined surfaces of the cathode forming materials, and is formed by the cathodes. Each of the materials is energized to melt the bonding material, and one of the cathode forming materials and the other cathode forming materials are joined.

In the method for producing a cathode according to the present invention, the cathode includes a body portion including a body portion and a front end portion continuous to an end surface of the body portion, and one of the cathodes is formed. The material is a front end portion forming material that constitutes the front end portion, and the other cathode forming material is a body portion forming material that constitutes the body portion. The manufacturing method includes a protrusion forming process and is attached to the body. a projection portion constituting the joint portion is formed on a joint surface of at least one of the portion forming material and the front end portion forming material; and the joining process is performed by forming the front end portion of the protruding portion and the body portion or the front end portion In a state in which the joined surfaces of the formed materials are opposed to each other, the protrusions are melted and joined by energizing each of the body portion forming material and the tip end portion forming material.

In the method of manufacturing the cathode of the present invention, it is preferred The cutting process is performed by cutting at least a part of the fusion portion due to the protrusion portion by the joint body formed by the joint work, and forming the end portion of the truncated cone shape. .

In the method for producing a cathode of the present invention, it is preferable that the protrusions are formed in a ring shape.

In particular, it is preferable that at least one of the body portion forming material and the tip end portion forming material is formed with a discharge material recessed portion, and the discharge material recessed portion is provided with a discharge material containing the discharge material. The container is housed in a state exposed by the joined surface, and the protruding portion is formed at a position surrounding the opening of the recess for the discharge material.

In the method for producing a cathode according to the present invention, the body portion forming material is made of tungsten, and the tip end portion forming material is made of tungsten doped with a substance.

According to the short arc type discharge lamp of the present invention, it is possible to partially contain the cathode of the discharged substance at a necessary portion, and it is possible to maintain a sufficiently high machine even at a high temperature in the lamp lighting. The strength is strong, and the desired lighting startability can be stably obtained.

In addition, a discharge material is disposed in a sealed space surrounded by two cathode forming materials in which the joined surfaces are hermetically joined via a bonding material, even in a discharge lamp. At the time of lighting, there is no case where the discharged material is ejected from the joint surface to the outside, and it is possible to cover the lighting state for a long period of time.

In particular, it is extremely useful in the case of constituting a cathode containing a substance which is formed by a rare metal compound which is more easily evaporated than a substance which is formed by a ruthenium compound.

According to the method for producing a cathode according to the present invention, it is possible to produce a cathode partially containing a substance to be discharged at a necessary portion in a short time by a simple method, and the obtained cathode is even The mechanical strength can also be maintained at high temperatures in the lamp lighting.

10‧‧‧Light tube

11‧‧‧Lighting Department

12‧‧‧Seal of one of the parties

13‧‧‧The seal of the other party

16‧‧‧Connectors

17‧‧‧Connector

20‧‧‧Anode

21‧‧‧ Body components

21a‧‧‧Central Department

21b‧‧‧ front end

21c‧‧‧ back end

24‧‧‧Electrode shaft

30‧‧‧ cathode

31‧‧‧ Body Department

31a‧‧‧1st recess

31b‧‧‧2nd recess

32‧‧‧ Body Department

33‧‧‧Recessed material recess

34‧‧‧ recesses for mandrel members

35‧‧‧ front end

37‧‧‧Electrode shaft

38‧‧‧Little Trails Department

39‧‧‧The Great Trails Department

40‧‧‧ Body forming material

40s‧‧‧The bottom surface of the 1st recess

42‧‧‧ body parts

42a‧‧‧Metal body for body formation

42s‧‧‧ front face

45‧‧‧ front end forming material

45a‧‧‧Metal body

45s‧‧‧ rear end face

47‧‧‧ mandrel components

47s‧‧‧ front face

48‧‧‧ joint

48a‧‧‧cutted part

48x‧‧‧fused part

50‧‧‧metal foil

50a‧‧‧Metal body

51‧‧‧through holes

55‧‧‧Protruding

56‧‧‧ end face

60‧‧‧Power supply for current supply

E‧‧‧ release material

M‧‧‧Confined space

S‧‧‧discharge space

Fig. 1 is an explanatory view showing a configuration of one of the arc-shaped discharge lamps of the present invention, and showing a part of the arc tube.

[Fig. 2] is a cross-sectional view for explaining a schematic example of one of the cathodes of the short arc type discharge lamp of the present invention.

[Fig. 3] is a cross-sectional explanatory view for explaining the constitution of the cathode forming material used in one of the manufacturing methods of the cathode shown in Fig. 2.

[Fig. 4] is a cross-sectional explanatory view showing a state in which a metal foil constituting a bonding material and a metal foil constituting the bonding material are disposed on a body portion forming material of a cathode forming material constituting the body portion.

[Fig. 5] is a cross-sectional explanatory view for explaining a joining process of the body forming material and the tip end portion forming material of the cathode forming material constituting the tip end portion.

[Fig. 6] is for the joint body obtained by the joining process A cross-sectional view of the description of the cutting work performed.

FIG. 7 is a cross-sectional explanatory view for explaining a configuration of a cathode forming material constituting a main body portion used in another example of the method for producing a cathode.

(Fig. 8) is a cross-sectional view for explaining a state in which a projection is formed in a front end portion forming material of a cathode forming material that constitutes a tip end portion.

[Fig. 9] is a cross-sectional explanatory view for explaining a joining work of a trunk portion forming material and a tip end portion forming material which are cathode forming members constituting the body portion.

FIG. 10 is a cross-sectional view for explaining the cutting work performed on the joined body obtained by the joining process.

[Fig. 11] is a cross-sectional explanatory view for schematically showing a configuration example of a main portion of a cathode formed of a cathode forming material shown in Fig. 7.

FIG. 12 is a cross-sectional explanatory view for schematically showing a configuration of a main body portion in another configuration example of the cathode.

[Fig. 13] is a cross-sectional view for explaining the other exemplary configuration of the cathode in the short arc type discharge lamp of the present invention.

[Fig. 14] is a cross-sectional explanatory view showing a configuration of a cathode forming material used in an example of the method for producing a cathode shown in Fig. 13.

[Fig. 15] is a cross-sectional view for explaining another example of another configuration of the cathode.

Hereinafter, embodiments of the present invention will be described in detail.

Fig. 1 is an explanatory view showing a configuration of one of the arc-shaped discharge lamps of the present invention, and showing a part of the arc tube.

This discharge lamp has an arc tube 10 made of, for example, quartz glass. The arc tube 10 is integrally formed continuously along the tube axis by the light-emitting portion 11 having a spheroidal shape in the form of a spheroidal shape formed by the inside of the discharge space S and the both ends of the light-emitting portion 11 The sealing portion 12 of one of the rod-like shapes extending toward the outside and the sealing portion 13 of the other one are formed.

In the discharge space S of the arc tube 10, the anode 20 and the cathode 30 are arranged to face each other along the axial direction of the arc tube 10.

In the light-emitting portion 11 of the arc tube 10, for example, a luminescent material such as a rare gas such as mercury or helium is sealed.

The anode 20 is made of, for example, tungsten, and includes a body portion 21 and an electrode shaft portion 24 that holds the body portion 21. The main body portion 21 is a cylindrical central portion 21a extending in the axial direction of the arc tube 10, and a truncated cone-shaped front end portion 21b formed continuously from the front end of the central portion 21a, and continuous to the center The truncated cone-shaped rear end portion 21c formed at the rear end of the portion 21a is configured.

The electrode shaft portion 24 at the anode 20 is such that its front end is engaged with the rear end portion 21c of the body member 21, and along the arc tube 10 The axial direction is arranged such that one of the sealing portions 12 extends into the discharge space S. Further, the electrode shaft portion 24 is supported by the one of the sealing portions 12 by having the base end portion embedded in one of the sealing portions 12.

Inside one of the sealing portions 12, a metal foil (not shown) made of molybdenum is hermetically embedded by, for example, a shrink seal. At one end of the metal foil, the base end of the electrode shaft portion 24 is welded and electrically connected. Further, at the other end of the metal foil, an external lead (not shown) that protrudes outward from the outer end of the one of the seal portions 12 is welded, and is electrically connected.

The cathode 30 is provided with a substance to be discharged at the distal end side portion, and includes a body portion 31 and an electrode shaft portion 37 that holds the body portion 31. The configuration of the cathode 30 will be described later.

The electrode shaft portion 37 at the cathode 30 is disposed so as to extend from the other sealing portion 13 into the discharge space S along the axial direction of the arc tube 10. Further, the electrode shaft portion 37 is supported by the other sealing portion 13 by causing the base end portion thereof to be embedded in the other sealing portion 13.

In the inside of the other sealing portion 13, a metal foil (not shown) made of molybdenum is hermetically embedded by, for example, a shrink seal. One end of the metal foil is welded to the base end of the electrode shaft portion 37 to be electrically connected. Further, at the other end of the metal foil, the outer end of the sealing portion 13 from the other side is welded. The external wires (not shown) that protrude toward the outside are electrically connected.

In the discharge lamp of this example, the joints 16 and 17 are provided at the end portions of each of the seal portion 12 and the other seal portion 13. The connectors 16, 17 are electrically connected to external wires, respectively.

Further, in the discharge lamp of the present invention, there is a case where vertical lighting is present, and there is a case where horizontal lighting is performed, and Fig. 1 is not intended to limit the use form of the discharge lamp of the present invention.

Fig. 2 is a cross-sectional view for explaining a schematic example of one of the cathodes of the short arc type discharge lamp of the present invention.

The cathode 30 is provided with a main body portion 31 and an electrode shaft portion 37 that holds the main body portion 31 as described above.

The main body portion 31 is provided with a body portion 32 and a front end portion 35 that is continuous with the front end surface of the body portion 32, and is formed of a body forming member that constitutes the cathode forming member of the body portion 32 by a joining material. The front end portion forming material of the cathode forming material constituting the front end portion 35 is joined to each other. Inside the main body portion 31, a sealed space M surrounded by the cathode forming materials is formed, and in the sealed space M, the discharge material E is disposed.

The trunk portion 32 has a shape having a substantially cylindrical shape as a whole, and is formed in a truncated cone shape in which the front end portion is reduced in diameter toward the distal end. The front end surface of the body portion 32 has an annular shape and is set to be a flat surface.

The trunk portion 32 is provided with a cylindrical recessed portion 33 for containing the discharge material E therein. The discharge material recessed portion 33 is opened at the cathode front end side (the upper end side in FIG. 2), and is formed to extend in the axial direction. The discharge material recessed portion 33 is formed in a state in which the central axis of the discharge material recessed portion 33 is aligned with the central axis of the trunk portion 32.

Further, at the rear end portion of the body portion 32, a substantially cylindrical mandrel member recess portion 34 into which a mandrel member constituting the cathode forming member of the electrode shaft portion 37 is inserted and joined is formed, the mandrel The member recessed portion 34 is opened at the rear end portion of the cathode (the lower end side in FIG. 2), and is in a state in which the central axis of the mandrel member recessed portion 34 is aligned with the central axis of the body portion 32. form.

The body portion 32 is composed of a tungsten member. In the present invention, the term "tungsten member" means a material containing tungsten as at least a main component, and may also contain a release substance or other components. As the tungsten member constituting the body portion 32, for example, pure tungsten having a purity of 99.99% by mass or tungsten doped with zirconia functioning as a particle growth inhibitor can be used. Further, in the cathode 30 of this example, since the body portion forming material and the front end portion forming material are mutually independent members, the body portion 32 and the front end portion 35 can be formed of mutually different materials. . Therefore, the body portion 32 does not need to be a body containing the released substance.

The distal end portion 35 is formed in a truncated cone shape that is reduced in diameter toward the distal end, and the rear end surface is a flat surface.

The front end portion 35 is composed of a tungsten member containing a substance to be discharged. Specifically, when ruthenium is used as the substance to be discharged, it can be formed by doping tungsten (thinium oxynitride) containing yttrium oxide (ThO ₂ ). Here, as a substance to be released, it is held in the state of thorium oxide (ThO ₂ ) or yttrium (Th) in tungsten which is a main component. Further, when a substance which does not contain a ruthenium-releasing substance is used, it can be constituted by tungsten doped with a rare metal compound as a substance to be discharged. Examples of the rare metal compound include cerium oxide, cerium oxide, and the like.

The concentration of the released matter contained in the distal end portion 35 is preferably 0.1 to 5.0% by mass, more preferably 0.3 to 2.5% by mass.

In the cathode 30, the body portion and the tip end portion forming material are hermetically joined via a bonding material to form a sealed space M which is generated by the releasing member recess portion 33.

In the cathode 30 having such a configuration, it is necessary to make the end portion 35 containing the released material and the discharge material E accommodated in the sealed space M in contact with each other. In particular, it is preferable that the material E is adhered to the end portion 35 before the release of the substance.

The discharge material E in this example is provided with a shape matching the shape of the closed space M, for example, has a cylindrical shape, and the front end surface (the upper end surface in FIG. 2) and the front end portion 35 are opposite to each other. Close.

The material E is, for example, a material containing a substance which does not contain cerium, and is specifically composed of a high melting point metal material and a sintered body of the substance.

As the high melting point metal material constituting the discharge material E, tungsten, Molybdenum, etc.

As the releasing substance contained in the discharge material E, a rare metal compound such as cerium oxide, cerium oxide, cerium oxide, cerium oxide, cerium oxide, cerium oxide or cerium oxide can be used.

The concentration of the substance to be released in the material E is preferably 10 to 80% by mass, more preferably 20 to 50% by mass. When the concentration of the substance to be released in the discharge material E is too small, it may be difficult to supply a sufficient amount of the discharge to the front end of the cathode 30. As a result, the lighting state of the discharge lamp will become unstable at an early stage. On the other hand, when the concentration of the substance to be released in the discharge material E is excessively large, since the ratio of tungsten in the discharge material E is low, the product due to the reduction of the oxide is reduced. As a result, the life of the cathode 30 is likely to be shortened.

The bonding material in this example is composed of, for example, a metal foil (metal foil) 50, and is disposed so as to be interposed between the annular front end surface of the trunk portion 32 and the rear end surface of the front end portion 35.

The metal foil 50 has a ring-shaped plate shape having a through hole 51 that matches the outer diameter of the front end surface of the body portion 32 and has an inner diameter (opening diameter) of the recessed portion 33 for the discharge material. (Refer to Figure 3). In this manner, the metal sheet 50 is provided with the through hole 51, and the discharge material E disposed in the sealed space M is configured to come into contact with the rear end surface of the front end portion 35.

The metal foil 50 is constructed by a metal material which is melted by energization of the front end portion forming material and the body portion forming material. to make. Specifically, the metal foil 50 is composed of a high-melting-point metal material different from the material constituting the front end portion forming material and the body portion forming material, or is the same as the front end portion forming material or the body portion forming material. Made up of materials.

As the high-melting-point metal material constituting the metal foil 50, a melting point lower than the melting point of the front end portion forming material and the body portion forming material is used, and the temperature of the front end portion 35 and the body portion 32 is higher than when the discharge lamp is lit. The melting point of the person.

Further, the metal foil 50 is formed at the joint portion (in this example, between the end surface of the front end portion 35 and the front end surface of the body portion 32), and an alloy is formed at least at the joint interface. Therefore, it is also necessary for the alloy to be a combination of alloy phases which will produce a temperature at which the temperature of the end portion 35 and the body portion 32 is higher before the discharge lamp is turned on. Moreover, in order to ensure the airtightness of the joint portion, it is necessary to avoid the phenomenon that the alloy of the joint portion is melted and the joint surface is peeled off when the discharge lamp is turned on.

Therefore, it is also necessary for the alloy to be in the case where the alloy of the joint portion does not generate a liquid phase when the discharge lamp is lit. In addition, it can be inferred that the temperature of the joint portion is about 2000 to 2500 °C.

Further, as the metal foil 50, a person who does not react with the enclosed substance in the light-emitting portion 11 is selected. Specifically, when the encapsulating substance is a rare gas, although no reaction occurs, when the encapsulating substance is mercury or a metal halide, alloying with mercury or halogenation occurs. The possibility of a reaction between.

Furthermore, the foil 50 is used as a sealing member. It is ideal for those who are malleable. In particular, when bonding is performed by resistance welding, since it is energized when pressurized, it is preferable that no chipping occurs during pressurization.

For the reason described above, as the high melting point metal material constituting the metal foil 50, tantalum (Ta), niobium (Nb), molybdenum (Mo), hafnium (Hf), rhenium (Re) or alloys thereof are used. The one chosen is ideal.

Further, as the bonding material, not only the metal foil 50 but also a molded body of metal powder can be used.

The electrode shaft portion 37 is made of, for example, tungsten, and includes a cylindrical small-diameter portion 38 that is inserted into the mandrel member recess portion 34 of the body portion 32, and is formed continuously in the small-diameter portion 38. The large diameter portion 39. The small diameter portion 38 has an outer diameter that is fitted to the mandrel member recessed portion 34, and the front end surface thereof is a flat surface. The large diameter portion 39 is provided with an outer diameter larger than the inner diameter of the recess portion 34 for the core rod member.

In the cathode 30 having the above-described configuration, the released material contained in the distal end portion 35 is reduced by being heated at a high temperature in the lamp lighting, and is an atom of cerium or a rare metal, and is further granulated by tungsten particles. The end face is diffused or the surface is diffused and the end face is moved and supplied before the temperature is high. Thereby, the work function of the front end surface of the cathode is lowered, and the electron emission characteristics are improved.

The cathode 30 shown in Fig. 2 can be manufactured, for example, as generally described below.

First, as shown in FIG. 3, the trunk portion forming material 42, the tip end portion forming member 45, and the core rod member 47 which are the cathode forming members constituting the body portion 32, the tip end portion 35, and the electrode shaft portion 37 are prepared. Moreover, the joining material and the discharge material E are prepared.

The body portion forming member 42 is formed by forming a cylindrical discharge material recess portion 33 at the front end side of the cylindrical body portion forming metal body 42a, and forming a substantially cylindrical core rod member at the rear end side. This is obtained by using the recess 34. The front end portion forming material 45 is a metal body having a cylindrical shape and has an outer diameter equal to the outer diameter of the body portion forming material 42. The mandrel member 47 can be cut by the tip end side portion of the cylindrical mandrel member having the outer diameter of the same size as the large diameter portion 39 to be formed, and the small diameter portion 38 can be formed. And get it. The rear end side portion of the metal body for the mandrel member constitutes the large diameter portion 39. Further, the metal foil 50 constituting the bonding material can be obtained, for example, by forming the through hole 51 at a specific position in the disk-shaped metal body 50a and forming it into an annular shape.

The material E can be produced as follows in general. First, by adding a binder such as stearic acid to a mixture of a powder of a high-melting-point metal material such as tungsten and a powder of a substance to be discharged (mass ratio of 1:1), the material for the discharge material is prepared. material. Next, the material for the discharge material is formed by press-pressing or the like. The obtained molded body is heated under a hydrogen atmosphere, for example, at a treatment temperature of 1000 ° C and a treatment time of 1 hour, whereby the molded body is subjected to degreasing and temporary sintering treatment. After that, for the molded body which has been subjected to degreasing and temporary sintering treatment, The main sintering treatment is carried out under reduced pressure at a treatment temperature of, for example, 1600 to 2000 ° C, preferably 1700 to 1900 ° C, and a treatment time of, for example, 1 hour, thereby obtaining tungsten containing the evolved substance. The discharge material E formed by the sintered body.

Next, a joining process in which the body portion forming material 42 and the tip end portion forming material 45 are joined via the metal foil 50 is performed. In this jointing process, first, as shown in Fig. 4, the cylindrical material E is placed in the body so that the body portion 42 is exposed at the front end surface 42s of the joint surface. The portion 42 of the material for the discharge material on the front end side of the portion forming material 42. Moreover, the annular metal foil 50 is placed on the front end surface of the body portion forming member 42 in a state in which the front end surface of the discharge material E is exposed. Thereafter, the front end portion forming material 42 is placed on the metal foil 50, and the metal foil 50 is held by the front end surface 42s of the body portion forming material 42 and the rear end surface 45s of the front end portion forming material 45 which is formed by the joint surface. Then, as shown in FIG. 5, the body portion 42 and the front end portion forming material 45 are energized in a state in which the joining direction (the upper and lower directions in FIG. 5) is pressurized. The resistor is welded to heat and melt the foil 50. The component symbol 60 in Fig. 5 is a current supply power source. Thereafter, the molten metal from the metal foil 50 is filled into the gap between the front end surface 42s of the trunk portion forming material 42 and the end surface 45s of the front end portion forming material 45, and is thereby fused. As shown in Fig. 6, a joint body 48 composed of the body portion forming member 42 and the front end portion forming member 45 is formed in a general manner. At the joint body 48, the opening of the recess 33 for the discharge material is formed by the front end portion. The material 45 is closed, and the inner space of the discharge portion recess 33 in which the discharge material E is accommodated is hermetically sealed to form a sealed space M. Such a joining process is carried out under reduced pressure or in an inert gas atmosphere, but it is preferably carried out under an Ar gas atmosphere.

The body portion precursor is formed by cutting the front end side portion of the joined body 48 thus obtained into a tapered shape. The broken line shown in Fig. 6 represents the cutting face.

Next, the main body portion precursor is subjected to vacuum heat treatment under the conditions of a treatment temperature of 1500 to 2400 ° C for 1 hour, for example, thereby forming the main body portion 31 of the cathode shown in FIG. 2 . Thereafter, the small diameter portion 38 of the mandrel member 47 is inserted into the mandrel member recess portion 34 at the body portion 31 to be joined. Examples of the bonding method of the core rod member 47 of the main body portion 31 include a spot welding method, a diffusion welding method, a press-fitting method, and the like. Thereby, the intended cathode 30 can be obtained.

The main body portion 31 of the cathode 30 having the configuration shown in FIG. 2 can be made of the same material as the front end portion forming material or the body portion forming material, and the front end portion forming material and the body portion forming material can be used as the joining material. Join and form. In this case, at least one of the front end portion forming material and the body portion forming material may be formed so that the joining material is integrally provided on the joined surface.

The method for producing such a cathode includes, for example, the following items (1) to (3).

(1) at least one of the body forming material and the front end forming material On one of the joined surfaces, a protrusion forming portion constituting the protruding portion of the bonding material is formed.

(2) The front end surface of the projection portion is placed in contact with the body forming material or the joined surface of the front end portion forming material, and the body forming material and the front end portion forming material are energized. The protrusion portion is melted, and the body portion forming material and the tip end portion forming material are fused to form a joint work of the joined body.

(3) Cutting is performed so that at least a part of the fused portion due to the protrusion remains for the joined body obtained through the joining process, thereby forming a cutting process at the end portion of the truncated cone shape.

(1) Projection of protrusions

As shown in FIG. 7, generally, the body portion forming member 42 and the front end portion forming member 45 are prepared.

The body portion forming material 42 can be obtained by forming a cylindrical recess portion 33 for discharging the material at the center portion of the front end side of the cylindrical metal body portion 42a. The front end portion forming material 45 is a metal body 45a having a cylindrical shape and has an outer diameter equal to the outer diameter of the main body portion forming material 41.

Next, as shown in FIG. 8, for example, at the rear end surface 45b of the metal body 45a constituting the front end portion forming material 45, a projection portion 55 constituting the bonding material is formed. As a method of forming the protrusions 55, for example, a method of cutting by a rotary disk or the like can be cited.

The projection 55 of this example is attached to the recess 33 for the discharge material. The position surrounded by the periphery of the opening is formed in an annular shape so as to extend over the entire circumference in the circumferential direction, and the end surface 56 of the protrusion 55 is set to be a flat surface. The end surface shape of the cut surface of the projection 55 along the axial direction of the cathode 30 is formed in a rectangular shape.

In the joining process of the trunk body forming material 42 and the tip end portion forming material 45, it is preferable to make the outer periphery of the material E to be adhered while ensuring the exposed surface of the discharge material E. Therefore, the projections 55 are formed in an annular shape so as to extend around the opening in the circumferential direction in a position surrounding the opening of the recessed portion 33 for the discharge material, whereby The end surface of the front surface portion 35 and the rear end surface of the front end portion 35 are brought into contact with each other, and the recessed portion 33 for the discharge material can be sealed by the outer peripheral portion. Therefore, it is possible to reliably supply the discharged material from the discharge material E to the distal end portion 35, and it is possible to suppress the release of the released material.

The projections 55 must be formed in a region portion (hereinafter also referred to as a "cut portion") which is cut in a cutting process to be described later, and further on the central axis side of the cathode 30.

The height of the projections 55 is preferably 0.1 to 1.0 mm, and the width of the end surface 56 of the projections 55 is preferably about 1 to 3 mm. The projections 55 can also be formed in a plurality of annular shapes so as to surround the central region of the rear end surface 45s constituting the joined surface of the distal end portion forming material 45.

Further, the area (Sw) of the end surface 56 of the projection 55 is also displayed as in the experimental example described later, from the viewpoint of the joint strength. It is preferable that the front end surface 42s of the joint surface of the joint body forming material 42 or the front end surface forming material 45 is 0.3 times or more the area (S) of the rear end surface 45s of the joint surface. More preferably, it is 0.5 times or more and 0.8 times or less.

(2) Joint engineering

As shown in FIG. 9, the columnar material E is placed in the recessed portion 33 for the discharge of the trunk portion forming material 42 so that the configuration of the trunk portion forming material 42 is exposed by the distal end surface 42s of the joint surface 42. . Thereafter, the end surface 56 of the projection 55 formed at the front end portion forming material 45 is brought into contact with the front end surface 42s of the body portion forming member 42, and the center axis of the front end portion forming member 45 and the center of the body portion forming member 42 are formed. The axes are aligned with each other to configure the opposite directions. When the state is maintained, the body portion forming material 42 and the tip end portion forming material 45 are energized while being pressed in the joining direction (upward and downward direction in FIG. 9). At this time, the body portion forming material 42 and the tip end portion forming material 45 are electrically heated, and the protruding portion 55 having a small heat capacity is melted compared to the material of the matrix having a large heat capacity. In this manner, by merely melting the projections 55 as the bonding material, the projections 55 and the front end faces 42s of the body forming members 42 are successively joined. Thereby, the body portion forming member 42 and the front end portion forming member 45 are fused, and as shown in FIG. 10, the joint body 48 formed by the body portion forming member 42 and the front end portion forming member 45 is formed.

Here, in the formed joint body 48, the body portion is formed in the body portion. The interface between the front end surface 42s of the front end 42 and the end surface 45s of the front end portion forming material 45 (hereinafter, also referred to as "joining surface"), except for the portion to be fused by the molten projection portion 55 (hereinafter Also known as the "melting part"), the area other than 48X is not fused.

The energization conditions vary depending on the size of each cathode forming material and the size of the protrusions 55. However, the amount of current is, for example, 5,000 to 10,000 Å, and the energization time is, for example, 5 to 20 seconds.

According to the above-described general joining process, it is possible to join in a short time compared to the diffusion bonding of the prior art, and the manufacturing time can be shortened. Here, in the diffusion bonding of the prior art, at the joint surface of each cathode forming material, since the bonding is performed without melting at a temperature lower than the melting point, the bonding time of one time is about 15 ~20 minutes.

Further, the above-described joining method is not a method of joining the surfaces in a complete plane. However, by forming the uniform fused portion 48X in the circumferential direction of the joint surface, it is possible to obtain the equivalent of the joint surfaces. The joint strength of the joint.

Further, since there is a region which is not fused at the joint surface, since the heat of the tip end portion 35 is hardly conducted to the body portion 32, the temperature of the tip end portion 35 is maintained at a high temperature, so that the discharge efficiency is also high. Being maintained.

(3) Cutting engineering

As shown in FIG. 10, in general, at least a part of the fused portion 48X is left by the bonded body 48 formed by the joining process. The main body portion 31 including the cathode 30 having substantially the same configuration as that shown in Fig. 2 is formed by cutting by a rotary disk or the like. The body portion 31 thus obtained is shown in Fig. 11. In the main body portion 31, the protruding portion 55 as a bonding material formed at the front end portion forming material 45 is integrated with the body portion forming material 42.

In the cutting process, it is necessary to perform cutting so that the entire melting portion 48X is not removed, but it is preferable from the viewpoint of the mechanical strength of the obtained cathode 30. In the case of 10, as shown by the broken line, the outer portion of the more fused portion 48X is cut. That is, although the cut portion 48a can partially overlap the fused portion 48X, it is preferable that the cut portion 48a is positioned further outward than the fused portion 48X.

Further, in the example shown in FIG. 10, although one portion of the body portion forming material 42 is cut, it is also possible to cut only the tip end portion forming material 45.

As described above, in the method of manufacturing the cathode 30 described above, the front end surface 42s of the joint surface of the trunk body forming material 42 and the rear end surface of the joint surface of the front end portion forming material 45 are provided. The bonding material made of the metal foil 50 or the projections 55 between the 45s is heated by energizing the body portion forming material 42 and the front end portion forming material 45, and the bonding material is melted, thereby forming the body portion forming material 42 and The front end portion forming material 45 is fused and joined to join. Therefore, the joining process for the airtight joining of the trunk portion forming material 42 and the tip end portion forming member 45 in which the sealed space M in which the discharging material E is accommodated is partitioned It is easier and shorter to perform than the diffusion bonding of the prior art, and the manufacturing time of the cathode 30 itself can be shortened. Further, the obtained cathode 30 is provided with a sufficiently high mechanical strength even at a high temperature in the discharge lamp lighting.

Further, in the main body portion 31 of the cathode 30 obtained by the above-described manufacturing method, the discharge member 43 is disposed in the sealed space M surrounded by the trunk portion forming material 42 and the tip end portion forming material 45. The body portion forming material 42 and the tip end portion forming material 45 are airtightly joined to each other via the joining material. Therefore, according to the discharge lamp provided with the cathode 40, even when the discharge lamp is turned on, there is no possibility that the discharged material is ejected from the joint surface to the outside, and the stability can be achieved over a long period of time. Lighted state. In particular, the cathode 30 of the present invention is formed in the case of constituting a cathode containing a substance which is formed by a rare metal compound which is more easily evaporated than that of a discharge material composed of a ruthenium compound. The structure is extremely useful.

In the present invention, various modifications are possible without departing from the above embodiments.

For example, the recess for discharging the material may be formed at at least one of the body forming material and the front end forming material, as shown in FIG. 12, or at the end forming portion before the front end portion 35 is formed. The recess 33 for the discharge material is formed.

Further, for example, the protruding portion 55 as the bonding material may be formed in the body portion forming material 42 or may be formed on both the body portion forming member 42 and the front end portion forming member 45. The protrusion 55, when formed In the case where both the body portion forming member 42 and the tip end portion forming member 45 are formed, it is preferable that the end faces 56 of the both protruding portions 55 are opposed to each other.

Furthermore, for example, the protrusion 55 is not limited to being formed in a ring shape, and may be formed, for example, in a disk shape. Even when the protrusion 55 is formed in a ring shape, a state in which a gap is partially formed may be obtained. In addition, the end surface shape of the cut surface of the projection portion 55 along the axial direction of the cathode 30 is, for example, a table shape or a rectangular shape. However, the end surface 56 of the protrusion portion 556 is not limited to being flat. Face, but also a curved surface.

Furthermore, the sealed space M in which the discharge material E is accommodated in the cathode 30 can be a body portion forming material which is a cathode forming material constituting the main body portion, and a cathode forming material constituting the electrode shaft portion. The composition of the core rod member is divided.

Fig. 13 is a cross-sectional view for explaining the other exemplary configuration of the cathode in the short arc type discharge lamp of the present invention.

The cathode 30 includes a main body portion 31 and an electrode shaft portion 37 that holds the main body portion 31, and is a body portion forming member that is a cathode forming member that constitutes the main body portion 31, and constitutes an electrode shaft portion. The mandrel member of the cathode forming material of 37 is joined to form. Inside the main body portion 31, a sealed space M surrounded by the cathode forming materials is formed, and in the sealed space M, the discharge material E is disposed.

The main body portion 31 of this example is formed in a shape having a substantially cylindrical shape, and is formed such that its front end portion is reduced in diameter toward the front end. The shape of the truncated cone.

The main body portion 31 includes a columnar first recess 31a into which the electrode shaft portion 37 is inserted, and a columnar second recess 31b in which the discharge material E is housed. The first recessed portion 31a has an opening at the rear end side (the lower end side in FIG. 13) and is formed to extend in the axial direction. The second recessed portion 31b is formed to extend in the axial direction continuously from the first recessed portion 31a, and has an inner diameter smaller than the inner diameter of the first recessed portion 31a. The first recessed portion 31a and the second recessed portion 31b are formed in a state in which the central axis is aligned with the central axis of the main body portion 31. The bottom surface 351a of the first recess 31a has an annular shape. The bottom surface 31c of the first recessed portion 31a and the bottom surface of the second recessed portion 31b are each a flat surface.

The main body portion 31 is formed by a tungsten member containing a substance to be discharged at least in the front end side portion. The concentration of the released substance is, for example, 0.1 to 3.0% by mass. As the substance to be discharged, an exemplified substance which constitutes the cathode 30 shown in Fig. 2 can be used.

The electrode shaft portion 37 is made of, for example, tungsten, and includes a cylindrical small-diameter portion 38 that is inserted into the first recess portion 31a of the main body portion 31, and a cylindrical shape that is formed continuously from the small-diameter portion 38. The large diameter section 39. The small diameter portion 38 has an outer diameter that matches the inner diameter of the first recess portion 31a, and the front end surface thereof is a flat surface. The large diameter portion 39 has an outer diameter larger than the inner diameter of the first recess portion 31a.

At the cathode 30, the body portion forming material and the core rod member are hermetically bonded via the bonding material, thereby forming the second The sealed space M generated by the recess 31b.

In the cathode 30, it is necessary to configure the end portion of the main body portion 31 containing the released material and the discharge material E in the sealed space M to be in contact with each other. In particular, it is preferable that the material E is to be adhered to the end portion before the release of the substance.

The discharge material E is provided with a shape that matches the shape of the closed space M partitioned by the body portion forming material and the core rod member, for example, has a cylindrical shape, and the front end surface thereof (the upper end surface in FIG. 13) The bottom surface of the second recess 31b of the main body portion 31 is adhered to each other.

As a material constituting the discharge material E, an example of a discharge material constituting the cathode 30 shown in Fig. 2 can be used.

The bonding material is formed, for example, by the metal foil 50, and is disposed so as to intervene in the annular bottom surface 40s of the first recess 31a and the peripheral edge portion of the front end surface 47s of the small diameter portion 38 of the electrode shaft portion 37. between.

The metal foil 50 is formed into an annular shape having an outer diameter that matches the inner diameter of the first recess 31a and has a through hole 51 that matches the inner diameter (opening diameter) of the second recess 31b ( Refer to Figure 14). Moreover, the metal foil 50 of this example may be a disk shape which does not have a through-hole.

As a material constituting the metal foil 50, a metal foil as a cathode constituting the cathode shown in Fig. 2 can be used as an example.

Such a cathode 30 can be manufactured, for example, as generally described below.

First, as shown in FIG. 14, the body portion is prepared. 40. The core rod member 47, the bonding material, and the discharge material E.

The main body portion forming material 40 is formed by the first concave portion 31a formed at the rear end side of the cylindrical main body portion forming metal body 40a, and the second concave portion 31b continuous with the first concave portion 31a. And further, the front end side portion is cut into a tapered shape to obtain it. The mandrel member 47 can be cut by the tip end side portion of the cylindrical mandrel member having the outer diameter of the same size as the large diameter portion 39 to be formed, and the small diameter portion 38 can be formed. And get it. The rear end side portion of the metal body for the mandrel member constitutes the large diameter portion 39. Further, the metal foil 50 constituting the bonding material can be obtained, for example, by forming the through hole 51 at a specific position in the disk-shaped metal body 50a and forming it into an annular shape. The material E can be produced in the same manner as the above method.

Next, a joining process in which the main body portion forming material 40 and the mandrel bar member 47 are joined via the metal foil 50 is performed. In this joining process, first, the columnar material E is discharged so that the front end surface thereof is exposed to the bottom surface 40s of the first recessed portion 31a of the joint surface of the main body portion forming material 40. The inside of the second recess 31b of the main body portion forming material 40. In the bottom surface 40s of the first recessed portion 31a, the metal foil 50 is placed on the bottom surface 40s of the first recessed portion 31a in a state in which the front end surface of the discharge material E is exposed. Thereafter, the small-diameter portion 38 of the mandrel member 47 is inserted into the first recessed portion 31a, and the metal foil 50 is formed by the bottom surface 40s of the first recessed portion 31a and the front end surface 47s of the joint surface of the core rod member 47. Hold on. Thereafter, by forming the material 40 and the core with respect to the body portion The rod member 47 is energized (resistance welding) in a state where the pressure is applied to the joining direction, and the metal foil 50 is heated and melted. The molten metal from the metal foil 50 is filled into the gap between the bottom surface 40s of the first recess 31a in the main body portion forming material 40 and the front end surface 47s of the mandrel member 47, and is fused. Thus, a cathode precursor in which the body portion forming material 40 and the core rod member 47 are joined to each other is formed. In the cathode precursor, the opening of the second recess 31b is closed by the core rod member 47, and the inner space of the second recess 31b in which the discharge material E is accommodated is hermetically sealed and formed. Confined space M. Such a bonding treatment is carried out under reduced pressure or in an inert gas atmosphere, but it is preferably carried out under an Ar gas atmosphere.

Thereafter, the target cathode 30 is obtained by subjecting the cathode precursor to vacuum heat treatment. The conditions of the vacuum heat treatment, for example, the treatment temperature is 2000 to 2400 ° C, and the treatment time is 1 hour.

As described above, in the method of manufacturing the cathode 30 described above, the bottom surface 40s of the first concave portion 31a constituting the joint surface of the main body portion forming material 40 and the constituent joint surface of the mandrel member 47 are provided. The metal foil 50, which is a joint material between the front end faces 47s, is heated and melted by energizing the body portion forming material 40 and the mandrel bar member 47, thereby melting the body portion forming member 40 and the mandrel member 47. Engagement and joint work. Therefore, the joining process for airtightly joining the main body forming material 40 and the mandrel member 47 in which the sealed space M in which the discharging material E is accommodated can be made easier than the diffusion bonding of the prior art. Ground and in a shorter time, and able to bring the cathode 30 itself The manufacturing time is shortened. Further, the obtained cathode 30 is provided with a sufficiently high mechanical strength even at a high temperature in the discharge lamp lighting.

Further, in the main body portion 31 of the cathode 30 obtained by the above-described manufacturing method, the discharge material E is disposed in the sealed space M surrounded by the main body portion forming material 40 and the core rod member 47, and the main body portions are formed. The material 40 and the mandrel bar member 47 are hermetically joined to each other via the bonding material made of the metal foil 50. Therefore, according to the discharge lamp provided with the cathode 40, even when the discharge lamp is turned on, there is no possibility that the discharged material is ejected from the joint surface to the outside, and the stability can be achieved over a long period of time. Lighted state. In particular, the cathode 30 of the present invention is formed in the case of constituting a cathode containing a substance which is formed by a rare metal compound which is more easily evaporated than that of a discharge material composed of a ruthenium compound. The structure is extremely useful.

Further, in the configuration in which the cathode is partially contained in a place where it is necessary, for example, a substance to be released by the crucible, as shown in FIG. 15, it may not be set inside the body portion. The configuration has a composition of the discharge material. The main body portion 31 of the cathode of this example is basically the same as the main body portion 31 having the configuration shown in Fig. 11 except that the discharge member is not provided.

In the case of manufacturing the main body portion 31 of the cathode 30 having such a configuration, the same can be used, for example, in the same manner as the method of manufacturing the main body portion 31 shown in Fig. 11, and the body portion and the front end can be formed. The bonding process between the part forming materials is performed more simply and in a shorter time than the diffusion bonding of the prior art, and the manufacturing time of the cathode itself can be shortened. Further, the obtained cathode is such that it has a sufficiently high mechanical strength even at a high temperature in the discharge lamp lighting.

Example [Experimental Example 1]

In the joining of the front end portion forming material and the body portion forming material, the joined body obtained by the diffusion bonding and the bonding material composed of the protruding portion are fused by the bonding body (hereinafter, also referred to as "protrusion" The joint obtained by the "fusion" was measured, and the joint strength was measured.

Specifically, it is an outer diameter made of pure tungsten. 15 mm, full length 80 mm 胴 body forming material (42), and outer diameter formed by tungsten doped with ThO ₂ (concentration of ThO ₂ : 2% by mass) The end portion forming material (45) of 15 mm and the total length of 80 mm was bonded by diffusion bonding and projection, and the tensile strength of the obtained joined body was measured. Further, in the case where the projection is melted, a projection portion (55) having a height of 1 mm is formed in an annular shape on the surface to be joined of the front end portion forming material.

Further, the measurement of the joint strength is carried out by appropriately changing the area Sw (mm ² ) of the end surface (56) of the projection (55). The area of the end surface (56) of the projection (55) is such that when the area of the joined surface (45s) of the front end forming material (45) is "S (mm ² )", it becomes 0.2 × S. The size of (mm ² ), 0.3 × S (mm ² ), 0.5 × S (mm ² ), and S (mm ² ).

According to the results of Table 1, it was confirmed that in the joined body of the present invention obtained by the protrusion of the projection, when the area Sw of the end surface of the protruding portion is 0.3 × S or more, the diffusion bonding can be obtained. Joint strength in case.

[Experimental Example 2] <Production Example 1 of Joint Body>

The body portion of the cathode having the configuration shown in Fig. 15 was produced through the work shown below.

(1) Projection of protrusions

Each of the cathode forming materials was subjected to a cutting treatment so as to have the following dimensions, and the surface was subjected to polishing and washing treatment, and hydrogen treatment was performed at 1000 °C. Further, a protruding portion (55) as a bonding material is formed at the front end portion forming material (45).

Dimensions of the body part (42): outer diameter 10mm, full length 18mm

Material of the body part (42): pure tungsten

The size of the front end forming material (45): outer diameter 10mm, full length 10mm

Material of the front end portion forming material (45): tungsten doped with ThO ₂ (concentration of ThO ₂ : 2% by mass)

The size of the protrusion (55) is 7 mm in outer diameter, 2.4 mm in width, and 1 mm in height, and the area of the end surface (56) is 0.3 times the area of the joined surface (45s) of the front end portion forming material (45).

(2) Joint engineering

In a state in which the end surface (56) of the protrusion portion (55) and the joint surface (45s) of the front end portion forming material (45) are in contact with each other, the body portion forming member (42) and the body portion forming member (42) are disposed. The front end portion forming material (45) was pressurized in the joining direction under a pressurizing condition of 5 kN under pressure, and was energized with an electric current of 10000 A for 10 seconds.

(3) Cutting engineering

The bonded body formed by the joining process was cut so as to have the following dimensions, and then washed, and further subjected to vacuum heat treatment to produce a main body portion (31) of the cathode (hereinafter) It is called "joined body [A]"). The joined body [A] is used, for example, as a body portion of a cathode for a 7 kW xenon lamp.

Dimensions of the joint body [A]: outer diameter 10 mm, full length 21 mm, front end angle 40 degrees

<Production Example 2 of Joint Body>

The body portion of the cathode having the configuration shown in Fig. 11 was produced through the work shown below.

(1) Projection of protrusions

Each of the cathode forming materials was subjected to a cutting treatment so as to have the following dimensions, and the surface was subjected to polishing and washing treatment, and hydrogen treatment was performed at 1000 °C. Moreover, the protrusion part (55) is formed in the front-end part formation material (45), and the discharge material recessed part (33) is formed in the body part formation material (42).

Dimensions of the body part (42): outer diameter 8mm, full length 41.5mm

Material of the body part (42): pure tungsten

The size of the front end forming material (45): outer diameter 8mm, full length 10mm

Material of the front end portion forming material (45): tungsten doped with CeO ₂ (concentration of CeO ₂ : 2% by mass)

The size of the protrusion (55) is 5.6 mm in outer diameter, 1.1 mm in width, and 1 mm in height, and the area of the end surface (56) is 0.3 times the area of the joined surface (45s) of the front end portion forming material (45). size

Dimensions of the recess for the discharge material (33): hole diameter 2.5mm, full length 3mm

Material of the releasing member (E): sintered body of CeO ₂ , ZrO ₂ , W

(2) Joint engineering

Inserting the discharge member (E) into the recess for the discharge material (33), and The end surface (56) of the protruding portion (55) and the joined surface (45s) of the front end portion forming material (45) oppose each other and abut against each other, and the body forming material (42) and the front end forming material (45) are formed on one side. When the pressure was applied to the joining direction under a pressurization condition of 3 kN, the current was supplied with an electric current of 6000 A for 10 seconds.

(3) Cutting engineering

The bonded body formed by the joining process was cut so as to have the following dimensions, and then washed, and further subjected to vacuum heat treatment to produce a main body portion (31) of the cathode (hereinafter) , called "joined body [B]"). The joined body [B] is, for example, a user who is a body portion of a cathode for a 2 kW high-pressure UV lamp.

Dimensions of the joint body [B]: outer diameter 8 mm, full length 50 mm, front end angle 40 degrees

<Production Example 3 of Joint Body>

In the production example 1 of the joined body, no protrusion was formed in the projection forming process, and in the joining process, diffusion bonding was performed by vacuum processing, heat treatment (1800 ° C, 7 minutes), and cooling treatment. In the same manner as in Production Example 1, the main portion of the cathode for comparison (hereinafter referred to as "joined body [C]") was produced.

The tensile strengths of the joined bodies [A], [B] and the joined body [C] obtained as described above were measured, and as a result, the joint strength was the same.

As is apparent from the above results, in general, if the bonding method by the protrusion fusion according to the present invention can be made in a shorter time than the diffusion bonding, it is possible to obtain A bonded body having the same mechanical strength as the joined body due to diffusion bonding.

(Example 1)

According to the configuration shown in Fig. 2, a cathode [1] having the following specifications was produced.

Carcass member: material = tungsten doped with zirconia (ZrO ₂ ) (concentration of ZrO ₂ is 2wt%), maximum outer diameter = 12mm, length in the axial direction = 18mm, inner diameter of the front end face (opening diameter of the recess) =3.0mm

Inner diameter of the recess for the discharge material = 3.0mm

Inner diameter of the recess for the mandrel member = 3.8 nm, length in the axial direction = 8.5 mm

Front end forming material: material = tungsten doped with lanthanum oxide (La ₂ O ₃ ) and zirconia (ZrO ₂ ) (concentration of La ₂ O ₃ is 2.5 wt%, concentration of ZrO ₂ is 0.1 wt%), cutting The outer diameter of the front end face = 12mm, the length of the axial direction = 3.0mm

Release material: material = sintered cerium oxide (CeO ₂ ) and tungsten (W) (mass ratio of CeO ₂ and W is 1:1), outer diameter = 2.5 mm, length in the axial direction = 5.0 mm

Mandrel member: material = tungsten, full length = 155mm, outer diameter of small diameter section = 3.75mm, outer diameter of large diameter section = 6.0mm

Sheet metal: material = 钽 (Ta), size before cutting (for joint materials) The size of the metal foil is OD = 12 mm, inner diameter (aperture of through hole) = 3.4 mm, thickness = 20 μm (maximum 40 μm)

Moreover, the manufacturing conditions of the above-mentioned cathode are as follows.

[release material]

Degreasing, temporary sintering treatment: under hydrogen atmosphere, treatment temperature = 1000 ° C, treatment time = 1 hour

Formal sintering treatment: under reduced pressure (1 × 10 ^-5 Pa or less), treatment temperature = 1800 ° C, treatment time = 1 hour

〔cathode〕

Bonding treatment: The joint member (metal sheet for joint material) is heated and melted by welding a metal body between the body member and the metal member for the tip end member.

In an argon atmosphere, the current is 10000A, and the processing time is 10 seconds.

Further, the Ta foil was wound and pressed into the metal body for the body member and the mandrel member, and joined.

Vacuum heat treatment: under reduced pressure (1 × 10 ^-5 Pa or less), treatment temperature = 2200 ° C, treatment time = 1 hour

Using the above-described cathode [1], according to the configuration shown in Fig. 1, a discharge lamp [1] of the following specifications was produced.

Luminous tube: material = quartz glass, maximum inner diameter = 109mm

Anode: material = tungsten, outer diameter = 35mm, length in the axial direction = 65mm

Distance between electrodes: 9mm

Rated input: 7kW

The discharge lamp [1] described above was turned on under the conditions of a voltage of 35 V and a current of 140 A, and the lighting time until flickering was measured, and as a result, it was 500 hours. Further, the illuminance maintenance rate of the discharge lamp [1] from the start of lighting until 500 hours passed was 60%.

(Example 2)

According to the configuration shown in Fig. 13, a cathode [2] having the following specifications was produced.

Body member: material = tungsten doped with lanthanum oxide (La ₂ O ₃ ) and zirconia (ZrO ₂ ) (concentration of La ₂ O ₃ is 2.5 wt%, concentration of ZrO ₂ is 0.1 wt%), maximum outer diameter =12mm, length in the axial direction = 21mm

The inner diameter of the first recess is 5.0 mm, the length in the axial direction is 11 mm, the outer diameter of the bottom surface is 5.0 mm, and the inner diameter of the bottom surface is 3.0 mm.

Inner diameter of the second recess = 3.0mm

Release material: material = sintered cerium oxide (CeO ₂ ) and tungsten (W) (mass ratio of CeO ₂ and W is 1:1), outer diameter = 2.5 mm, length in the axial direction = 5.0 mm

Mandrel member: material = tungsten, full length = 155mm, outer diameter of small diameter section = 4.9mm, outer diameter of large diameter section = 6.0mm

Bonding material: material = tantalum (Ta), outer diameter = 4.95 mm, inner diameter (aperture of through hole) = 3.1 mm, thickness = 20 μm (maximum 40 μm)

Moreover, the manufacturing conditions of the above-mentioned cathode are as follows.

[release material]

Degreasing, temporary sintering treatment: under hydrogen atmosphere, treatment temperature = 1000 ° C, treatment time = 1 hour

Formal sintering treatment: under reduced pressure (1 × 10 ^-5 Pa or less), treatment temperature = 1800 ° C, treatment time = 1 hour

〔cathode〕

Bonding treatment: The joint material is heated and melted by resistance welding between the body member and the mandrel member.

In an argon atmosphere, the energizing current = 2000A, processing time = 10 seconds

Vacuum heat treatment: under reduced pressure (1 × 10 ^-5 Pa or less), treatment temperature = 2200 ° C, treatment time = 1 hour

Using the above-described cathode [2], according to the configuration shown in Fig. 1, a discharge lamp [2] of the following specifications was produced.

Luminous tube: material = quartz glass, maximum inner diameter = 109mm

Anode: material = tungsten, outer diameter = 35mm, length in the axial direction = 65mm

Distance between electrodes: 9mm

Rated input: 7kW

The discharge lamp [2] described above was turned on under the conditions of a voltage of 35 V and a current of 140 A, and the lighting time until flickering was measured, and as a result, it was 500 hours. Further, the illuminance maintenance rate of the discharge lamp [2] from the start of lighting until 500 hours passed was 60%.

[Comparative Example 1]

A cathode [3] for comparison was produced in the same manner as in Example 2 except that the bonding was carried out without using a bonding material. Further, a discharge lamp [3] having the same specifications as the discharge lamp [2] produced in the second embodiment was produced except that the cathode [3] for comparison was used.

The discharge lamp [3] described above was turned on under the conditions of a voltage of 35 V and a current of 140 A, and the lighting time until flickering was measured, and as a result, it was 100 hours. Further, the illuminance maintenance rate of the discharge lamp [3] from the start of lighting until 100 hours passed was 50%.

As is apparent from the above results, according to the discharge lamp [1] of the first embodiment and the discharge lamp [2] of the second embodiment, it can be confirmed that the stability can be achieved over a long period of time. Light status.

On the other hand, in the discharge lamp [3] of Comparative Example 1, the lighting state The system became unstable at an early stage. It is presumed that this is because, during the lighting of the discharge lamp, the release material is separated from the gap between the joint surfaces, that is, from the bottom surface of the first recess of the body member and the front end surface of the mandrel member. Leaks out, and the released material is not sufficiently supplied to the front end.

31‧‧‧ Body Department

32‧‧‧ Body Department

33‧‧‧Recessed material recess

34‧‧‧ recesses for mandrel members

35‧‧‧ front end

37‧‧‧Electrode shaft

38‧‧‧Little Trails Department

39‧‧‧The Great Trails Department

50‧‧‧metal foil

E‧‧‧ release material

M‧‧‧Confined space

Claims (12)

A short arc type discharge lamp is a short arc type discharge lamp in which a cathode and an anode having a substance to be discharged are disposed opposite to each other in a front end side portion, and the cathode is a plurality of The cathode forming material is formed by joining, and the cathode forming material containing one of the discharged materials and the other cathode forming material joined to the cathode forming material are each of the cathode forming materials. The bonding material which is interposed between each of the cathode forming materials is melted by energization, and bonding is performed. The short arc type discharge lamp according to the first aspect of the invention, wherein the cathode is provided with a sealed space surrounded by one of the cathode forming materials and the other cathode forming material. In the sealed space, a discharge material containing a release material that does not contain ruthenium is disposed. The short arc type discharge lamp according to claim 2, wherein the cathode includes a main body portion including a body portion and a front end portion continuous to an end surface of the body portion, One of the cathode forming materials is a front end portion forming material that constitutes the front end portion, and the other cathode forming material is a body portion forming material that constitutes the body portion, and the body member is provided along the body member. a concave portion extending in the axial direction and having an opening at the front end side of the cathode, the annular front end surface of the body portion forming material and the front end portion forming material Thereafter, the end faces are joined via the bonding material. The short arc type discharge lamp according to the second aspect of the invention, wherein the cathode includes a main body portion and an electrode shaft portion that holds the main body portion, and one of the cathode forming materials is configured as a body. The main body portion forming material of the main body portion, wherein the other cathode forming material is a core rod member constituting the electrode shaft portion, and the main body portion forming material is provided to extend along the axial direction and at the rear end side of the cathode a first recess having an opening, and a second recess extending in the axial direction and having an inner diameter smaller than an inner diameter of the first recess, the first portion of the main body forming material The annular bottom surface of the concave portion and the front end surface of the mandrel member are joined by the bonding material. The short arc type discharge lamp according to any one of claims 1 to 3, wherein the bonding material is the same as the cathode forming material or the other cathode forming material. The material is formed integrally with at least one of the cathode forming material and the other cathode forming material. The short arc type discharge lamp according to any one of claims 1 to 4, wherein the bonding material is from tantalum (Ta), niobium (Nb), molybdenum (Mo), niobium (Hf) ), 铼 (Re) and those selected among the alloys. A method for manufacturing a cathode, which is manufactured on the front end side portion A method for discharging a cathode for a short arc type discharge lamp of a substance, comprising: a cathode forming material containing one of the discharged materials; and a cathode forming material bonded to the one of the cathode forming materials The other cathode forming material is disposed such that a bonding material is interposed between the joined surfaces of the cathode forming materials, and each of the cathode forming materials is energized. The joining material is melted, and one of the cathode forming materials and the other cathode forming materials are joined. The cathode manufacturing method according to claim 7, wherein the cathode includes a body portion including a body portion and a front end portion continuous to an end surface of the body portion, wherein the cathode portion One of the cathode forming materials is a front end forming material constituting the front end portion, and the other cathode forming material is a body forming material constituting the body portion, and the manufacturing method includes a protrusion forming process. a projection portion constituting the joint portion on at least one of the joint surface of the body portion forming material and the front end portion forming material; and a joining process for forming the front end portion of the protrusion portion and the body portion In the state in which the joined surface of the front end portion forming material is opposed to each other, the protrusion portion is melted by energizing each of the body portion forming material and the front end portion forming material. Engage. The manufacturer of the cathode as described in item 8 of the patent application scope In the method of cutting, the cutting is performed so that at least a part of the fused portion due to the protruding portion remains in the bonded body formed by the joining process to form a cone The front end of the table shape. The method for producing a cathode according to the eighth or ninth aspect, wherein the protrusion is formed in a ring shape. The method for producing a cathode according to claim 10, wherein at least one of the body portion forming material and the tip end portion forming material is formed with a concave portion for a discharge material, and the concave portion for the discharge material. The material containing the release material is stored in a state where it is exposed at the surface to be joined, and the protrusion is formed at a position surrounding the opening of the concave portion for the discharge material. The method for producing a cathode according to claim 8, wherein the body portion forming material is made of tungsten, and the tip end portion forming material is made of tungsten doped with a substance.