WO2002054434A1 - Structure de cathode impregnee et procede d'elaboration - Google Patents
Structure de cathode impregnee et procede d'elaboration Download PDFInfo
- Publication number
- WO2002054434A1 WO2002054434A1 PCT/JP2001/011468 JP0111468W WO02054434A1 WO 2002054434 A1 WO2002054434 A1 WO 2002054434A1 JP 0111468 W JP0111468 W JP 0111468W WO 02054434 A1 WO02054434 A1 WO 02054434A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- base metal
- porous base
- impregnated
- cup body
- dense portion
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J1/00—Details of electrodes, of magnetic control means, of screens, or of the mounting or spacing thereof, common to two or more basic types of discharge tubes or lamps
- H01J1/02—Main electrodes
- H01J1/13—Solid thermionic cathodes
- H01J1/20—Cathodes heated indirectly by an electric current; Cathodes heated by electron or ion bombardment
- H01J1/28—Dispenser-type cathodes, e.g. L-cathode
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J9/00—Apparatus or processes specially adapted for the manufacture, installation, removal, maintenance of electric discharge tubes, discharge lamps, or parts thereof; Recovery of material from discharge tubes or lamps
- H01J9/02—Manufacture of electrodes or electrode systems
- H01J9/04—Manufacture of electrodes or electrode systems of thermionic cathodes
- H01J9/042—Manufacture, activation of the emissive part
- H01J9/047—Cathodes having impregnated bodies
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
Definitions
- the present invention relates to an impregnated cathode structure in which a porous base metal is impregnated with an electron-emitting substance and a method for producing the same, and more particularly, to joining of a porous base metal to a cup body that covers the bottom and side surfaces thereof.
- the present invention relates to an impregnated cathode structure having an improved structure and a method for producing the same.
- the impregnated cathode assembly operates at a high current density and has a long service life, it is often used as a cathode for electron guns used in traveling-wave tubes for use in satellites, CRTs for high-definition video systems, and imaging tubes. ing.
- a porous base metal impregnated with an electron-emitting substance is held and joined in a cup made of a high-melting-point metal, and the cup is placed on the top of a cathode sleeve made of a similar high-melting-point metal. Formed.
- porous base metal for example, a porous pellet made of a tungsten (W) sintered body having a diameter of about lmm, a thickness of about 0.4 mm, and a porosity of about 20% is used.
- This porous pellet can be formed by pressing a tungsten (W) having a particle size of about 5 m into a pellet shape and then heating and sintering it.
- tantalum (T a) is used as the high-melting point metal cap body and the high-melting point metal cathode sleeve body.
- a porous base metal 1 consisting of a porous tungsten (W) pellet impregnated with an electron-emitting substance is mounted in a cup 2 made of evening (Ta). Then, the cup body 2 is fitted inside the upper end of a tantalum (Ta) sleeve body 3, and the entire outer periphery of the upper end of the sleeve body 3 is caulked with a caulking welding electrode 4 and simultaneously resistance welded.
- the porous base metal 1, the cup body 2, and the sleeve body 3 are fixedly joined to each other.
- the laser welding method involves placing a porous base metal 1 made of porous tungsten (W) pellets impregnated with an electron emitting substance into a tantalum (T a) cup body 2. After attaching the cup body 2 to the inside of the upper end of the sleeve body 3 made of tantalum (Ta), the entire circumference of the outer periphery of the upper end of the sleeve body 3 is laser-welded to obtain a porous base metal. 1. The cap body 2 and the sleeve body 3 are fixedly joined to each other.
- a metal foil chip made of a high melting point metal such as molybdenum (Mo) with a thickness of about 15 to 100 xm on the bottom surface of a porous base metal 1 made of porous tungsten (W) pellets
- Mo molybdenum
- W porous tungsten
- the porous base metal 1 and the cup body 2 can be firmly joined to each other even though the entire circumference is not required, and the temporal change of the cathode temperature is suppressed. While the effect of reducing the change in the cut-off voltage can be obtained, there is a problem that the cost increase due to the use of the metal foil is unavoidable, and the porous base metal 1 and the cup 1 are connected via the metal foil chip 5. In order to surely perform laser welding with the body 2, it is necessary to control the flatness of the surface of the metal foil chip body 5 after welding, but this is a problem that is difficult.
- the surface of the porous base metal 1 has many pores, so that the surface on which the metal foil chip body 5 is formed is not flat, and the metal foil itself is slightly curved because it is extremely thin. Therefore, when the metal foil is placed on the bottom surface of the porous base metal 1 instead of the completely flat surface, a gap is generated between the two. When the metal foil chip body 5 is welded in such a state having a gap, a non-flat portion of projections and irregularities is formed on the surface of the metal foil chip body 5.
- the metal foil chip body 5 is welded by irradiating a laser beam in an atmosphere of an inert gas such as argon or nitrogen.
- an inert gas such as argon or nitrogen.
- the flatness of the surface of the metal foil chip body 5 after welding changes depending on the welding atmosphere, the flow rate of the inert gas spraying, the spraying direction, the laser irradiation condition, and the like.
- the porous base metal 1 When the porous base metal 1 is held in the wig body 2 and welded by laser irradiation with the non-flat portion existing on the surface of the metal foil chip body 5 as described above, the porous base metal is In some cases, the 1 was placed at an angle, and a hole was sometimes opened in the cup body 2 due to the irradiation of one laser beam.
- porous base metal 1 is arranged in the cup body 2 at an angle, poor welding is likely to occur due to the occurrence of an unwelded portion, and the porous base metal 1 may come off the cup body 2, Porous base metal even when welded
- the present invention has been made to address the above problems, and the first problem is that a porous base metal and a porous base metal can be used without using an intervening material such as a metal foil chip which causes an increase in cost. It is an object of the present invention to provide an impregnated cathode structure capable of firmly joining a cup body and a method for producing the same.
- Another object of the present invention is to eliminate the occurrence of poor welding by optimizing the shape of the porous base metal and the cup body that holds the porous base metal, and to reduce the possibility of the connection between the porous base metal and the cup body.
- An object of the present invention is to provide an impregnated cathode assembly capable of improving the reliability and yield of welding between the electrodes and a method of manufacturing the same.
- a further object of the present invention is to provide an impregnated cathode assembly capable of shortening the time required for welding work between a porous base metal and a cup body and reducing the manufacturing cost, and a method of manufacturing the same. Disclosure of the invention
- an impregnated cathode assembly includes a porous base metal impregnated with an electron emitting material, a surface of the porous base metal exposed, and a bottom surface and side surfaces thereof covered.
- the impregnated cathode assembly comprising a cap body for holding the porous base metal, a dense portion is formed on a bottom surface of the porous base metal, and a bottom portion of the cup body is added according to the shape of the dense portion.
- a pressure contact is formed to form a close contact region, and the bottom of the cup body and the dense portion of the porous base metal are welded in the close contact region.
- a nonporous dense portion is formed in a part of the porous base metal as described above, and the bottom portion of the force-applying body is pressed and deformed according to the shape of the dense portion to form a close contact region.
- the cup body and the porous base metal can be firmly joined directly by laser welding or the like without using any inclusion such as a metal foil.
- the dense portion of the porous base metal is formed in a convex shape
- the impregnated cathode structure is formed with the dense portion at the bottom of the cap body.
- the contact portion is formed in a convex shape on the metal side of the porous substrate, and the convex contact portion is deformed under pressure according to the shape of the dense portion to form a close contact region. .
- the dense portion of the porous base metal is formed in a convex shape
- the bottom of the cup body in contact with the convex portion is formed in a convex shape on the porous base metal side, and the convex contact portion is formed in the dense portion.
- an impregnated cathode structure according to the present invention is characterized in that, in the impregnated cathode structure described above, the dense portion of the porous base metal has a thickness of at least 10 m or more.
- the cup body and the porous base metal can be laser-welded without affecting the electron emitting material impregnated in the porous base metal.
- the width of the dense portion of the porous base metal may be reduced!
- the width of the convex portion is d
- the depth from the bottom surface of the concave portion formed on both sides of the convex portion is 1, and the height of the convex portion at the bottom of the cup body is a.
- the width of the bottom is b
- the width of the top of the convex portion is c
- a ⁇ l, b ⁇ r, and d ⁇ c are set.
- the porous base metal floats from the bottom surface of the forceps body. In such a case, it is possible to secure a sufficient contact area between the two and to perform welding, and to further stabilize the joining state.
- a method of manufacturing an impregnated cathode assembly includes the steps of: exposing a porous base metal impregnated with an electron-emitting substance; exposing a surface of the porous base metal; And a cup body for holding the porous substrate metal so as to cover the side surface.
- a dense portion is previously formed on the bottom surface of the porous substrate metal before impregnating with the electron-emitting substance.
- the bottom of the cup body follows the shape of the dense portion. Forming a contact area by pressurizing and deforming, and laser-welding the bottom of the power-up body and the dense portion of the porous base metal in the contact area. It is.
- the bottom of the press body is deformed under pressure according to the shape of the dense portion to form a close contact area, and in this close contact area, the press body and the porous base metal are laser-welded.
- the electron emitting material in a step after the step of forming the dense portion, may be appropriately applied to the porous base metal. It is characterized by being impregnated.
- the electron emitting material By forming a dense part on the bottom surface of the porous base metal and then impregnating the porous base metal with the electron emitting material, laser welding is performed without affecting the electron emitting material impregnated in the dense part. can do.
- FIG. 1 is a process flow chart showing a configuration of an impregnated cathode structure according to an embodiment of the present invention and a method of manufacturing the same.
- FIG. 2 is an enlarged cross-sectional view showing a welded region between the porous base metal and a cup body.
- FIG. 3 is a cross-sectional view showing a configuration of the porous base metal.
- FIG. 4 is a sectional view showing a configuration of the cup body.
- FIG. 5 is an explanatory view showing a conventional method for producing an impregnated cathode assembly by resistance welding.
- FIG. 6 is a process flow chart showing a method for manufacturing an impregnated cathode assembly by a conventional metal foil welding method.
- FIG. 1 is a process flow chart showing a configuration of an impregnated cathode structure according to an embodiment of the present invention and a method for producing the same
- FIG. 2 is an enlarged cross-sectional view showing a welding region between the porous base metal and a cup body
- FIG. 3 is a cross-sectional view showing a configuration of a porous base metal
- FIG. 4 is a cross-sectional view showing a configuration of a forceps body.
- each impregnated cathode assembly is made of a porous base metal 11 composed of porous tungsten (W) pellets impregnated with an electron-emitting substance and made of a high melting point metal such as tantalum (T a). It is held in a cup body 12 and formed by joining the cup body 12 to the top of a cathode sleeve made of a high melting point metal such as tantalum (T a).
- porous base metal 11 for example, a porous tungsten (W) pellet having a diameter of about lmm, a thickness of about 0.4mm, and a porosity of about 20% is used.
- the porous tungsten (W) pellets can be formed by, for example, pressing tungsten (W) having a particle size of about 5 m into a pellet shape, followed by heating and sintering.
- the back surface of the porous base metal 11 formed in this manner is irradiated with a laser beam, and a part of the porous portion 13 is melted to form a porous portion as shown in FIG. 1 (A).
- a dense portion 14 having fewer holes or harder than 13 is formed.
- the dense portion 14 is formed so that the central portion is convex and both sides are concave.
- the thickness t of the dense portion 14 is at least 10 so that laser welding can be performed with a cup body 12 described later without affecting the electron emitting material impregnated in the porous base metal 11. It is set above.
- the width of the dense portion 14 is set to r, the width of the convex portion is set to d, and the depth from the bottom surface of the concave portion formed on both sides of the convex portion is set to 1.
- the cup body 12 for holding and holding the porous base metal 11 so as to cover the bottom and side surfaces thereof is made of tantalum (T a) which is a high melting point metal, and the porous base metal 11 is placed on the surface thereof. Is held in an exposed state so that the electrons of the electron emitting substance can be emitted from the It is configured so that the dense portion 14 of the base metal 11 can be firmly joined by laser welding.
- T a tantalum
- the cup body 12 has a contact portion 15 formed in the center of the bottom with a convex shape with respect to the bottom surface side of the porous base metal 11.
- the contact portion 15 has dimensions such that the height of the projection is a, the width of the bottom of the projection is b, and the width of the top of the projection is c.
- the dimensions a, b, and c of the convex contact portion 15 of the cup body 12 and the dimensions of the dense portion 14 of the porous base metal 11! :, D, 1 are set to satisfy the relations a ⁇ l, b ⁇ r d ⁇ c.
- the porous base metal 11 and the cup body 12 are each configured as described above.
- an electron emitting substance is impregnated in the porous base metal 11 in which the above-described dense portion 14 is formed by irradiating a part of the bottom surface with a laser beam.
- the step of impregnating the electron-emitting substance may be set before or after any of the following steps (C) and (D).
- the cup body 12 described above is pressed against the porous base metal 11 impregnated with the electron-emitting substance so as to cover the bottom surface and the side surface on which the dense portion 14 is formed.
- the convex contact portion 15 of the cup body 12 is in contact with the convex portion of the dense portion 14 of the porous base metal 11.
- the convex contact portion 15 is pressurized and deformed, and the convex contact portion 15 is pressed and deformed so as to adhere to the shape of the convex portion of the dense portion 14.
- the convex contact portion 15 of the cup body 12 is pressed and deformed so as to follow the shape of the convex part of the dense part 14 and is brought into a close contact state, a state as shown in FIG.
- the deformation area 2 is a dense part.
- a completely adhered area 16 is formed in a state where there is no gap, and this portion forms a laser-weldable area in a state where there is no gap.
- the dimensions a, b, and c of the convex contact portion 15 of the cup body 12 and the dimensions r, d, and 1 of the dense part 14 of the porous base metal 11 are represented by a ⁇ l, b ⁇ r, Since the setting is made so as to satisfy d ⁇ c, the porous base metal 11 can be prevented from floating from the bottom of the cup body 12 and the dense part 14 and the convex contact part 15 can be prevented.
- the maximum contact area (two laser weldable area) 16 can be set.
- the close contact area between the dense portion 14 of the porous base metal 11 and the convex contact portion 15 of the cup body 12 (two laser weldable areas)
- the porous base metal 11 and the cup body 12 constituting the impregnated cathode structure are each formed into a shape having a convex dense portion 14 and a convex contact portion 15,
- the convex contact portion 15 of the cup body 12 is pressurized and deformed in accordance with the convex shape of the dense portion 14 of the porous base metal 11 to form a close contact region 16 with no gap between both portions.
- the porous base metal 11 and the cup body 12 are directly joined by laser welding, so that the conventional resistance welding method, laser welding method or The following effects that cannot be obtained by the metal foil welding method can be expected.
- Laser welding can be performed by forming a tight contact area 16 between the dense part 14 and the convex contact part 15 without any gaps.
- the yield of welding can be improved and the incidence of defective products can be reduced.
- the porous base metal 11 and the cap body 12 can be welded by irradiating the contact area 16 with a laser beam, the required welding time can be shortened, thereby reducing the manufacturing cost. be able to.
- the thickness t of the dense portion 14 is set to at least 10 m or more so that laser welding can be performed without affecting the electron-emitting substance impregnated in the porous base metal 11.
- the step of impregnating the electron emitting material can be set at an arbitrary position, and the degree of freedom can be ensured.
- the porous base metal and the cup can be manufactured without using an intervening material such as a metal foil chip which causes a cost increase in the production of the impregnated cathode structure. Can be firmly welded.
- the quality of the impregnated cathode assembly can be improved, the operation of the electron gun can be stabilized, and the cost can be reduced.
- the porous base metal is Can improve the reliability and yield of welding between the steel and the cup body, greatly reduce the incidence of defective products, and can equalize the welding accuracy and strength and improve the product quality .
- the time required for welding work between the porous base metal and the cup body can be reduced, manufacturing costs can be reduced, and laser welding can be performed without affecting the electron-emitting substance impregnated in the porous base metal. Therefore, the step of impregnating the electron-emitting substance can be set at any optimum position.
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- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Solid Thermionic Cathode (AREA)
- Electrodes For Cathode-Ray Tubes (AREA)
- Laser Beam Processing (AREA)
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020027010957A KR20020077915A (ko) | 2000-12-27 | 2001-12-26 | 함침형 음극 구성체 및 그 제조 방법 |
EP01272874A EP1258898A1 (en) | 2000-12-27 | 2001-12-26 | Impregnated cathode structure and method of manufacturing the structure |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2000-396980 | 2000-12-27 | ||
JP2000396980A JP2002197964A (ja) | 2000-12-27 | 2000-12-27 | 含浸型陰極構体及びその製造方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2002054434A1 true WO2002054434A1 (fr) | 2002-07-11 |
Family
ID=18862179
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2001/011468 WO2002054434A1 (fr) | 2000-12-27 | 2001-12-26 | Structure de cathode impregnee et procede d'elaboration |
Country Status (7)
Country | Link |
---|---|
US (1) | US20030034724A1 (ja) |
EP (1) | EP1258898A1 (ja) |
JP (1) | JP2002197964A (ja) |
KR (1) | KR20020077915A (ja) |
CN (1) | CN1404615A (ja) |
TW (1) | TW536725B (ja) |
WO (1) | WO2002054434A1 (ja) |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61206131A (ja) * | 1985-03-08 | 1986-09-12 | Hitachi Ltd | 含浸形カソ−ド |
JPS6378429A (ja) * | 1986-09-19 | 1988-04-08 | Hitachi Ltd | 含浸形陰極構体の製造方法 |
US5128584A (en) * | 1990-03-13 | 1992-07-07 | Samsung Electron Devices Co., Ltd. | Impregnated cathode |
JPH06162916A (ja) * | 1992-11-26 | 1994-06-10 | Nec Kansai Ltd | 含浸型陰極構体およびその製造方法 |
JPH087744A (ja) * | 1994-06-27 | 1996-01-12 | Sony Corp | 含浸型陰極構体とその製造方法 |
JPH11260241A (ja) * | 1998-03-13 | 1999-09-24 | Sony Corp | 含浸型陰極構体およびその製造方法 |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0821310B2 (ja) * | 1986-09-03 | 1996-03-04 | 株式会社日立製作所 | 含浸形カソ−ドおよびその製造方法 |
-
2000
- 2000-12-27 JP JP2000396980A patent/JP2002197964A/ja active Pending
-
2001
- 2001-12-26 US US10/204,945 patent/US20030034724A1/en not_active Abandoned
- 2001-12-26 CN CN01805318A patent/CN1404615A/zh active Pending
- 2001-12-26 KR KR1020027010957A patent/KR20020077915A/ko not_active Application Discontinuation
- 2001-12-26 EP EP01272874A patent/EP1258898A1/en not_active Withdrawn
- 2001-12-26 TW TW090132323A patent/TW536725B/zh not_active IP Right Cessation
- 2001-12-26 WO PCT/JP2001/011468 patent/WO2002054434A1/ja not_active Application Discontinuation
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS61206131A (ja) * | 1985-03-08 | 1986-09-12 | Hitachi Ltd | 含浸形カソ−ド |
JPS6378429A (ja) * | 1986-09-19 | 1988-04-08 | Hitachi Ltd | 含浸形陰極構体の製造方法 |
US5128584A (en) * | 1990-03-13 | 1992-07-07 | Samsung Electron Devices Co., Ltd. | Impregnated cathode |
JPH06162916A (ja) * | 1992-11-26 | 1994-06-10 | Nec Kansai Ltd | 含浸型陰極構体およびその製造方法 |
JPH087744A (ja) * | 1994-06-27 | 1996-01-12 | Sony Corp | 含浸型陰極構体とその製造方法 |
JPH11260241A (ja) * | 1998-03-13 | 1999-09-24 | Sony Corp | 含浸型陰極構体およびその製造方法 |
Also Published As
Publication number | Publication date |
---|---|
KR20020077915A (ko) | 2002-10-14 |
CN1404615A (zh) | 2003-03-19 |
JP2002197964A (ja) | 2002-07-12 |
TW536725B (en) | 2003-06-11 |
US20030034724A1 (en) | 2003-02-20 |
EP1258898A1 (en) | 2002-11-20 |
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