JPS58108628A - Cathode structure and manufacture thereof - Google Patents

Abstract

PURPOSE:To obtain a cathode structure requiring small personal expenditure due to an yield and the selection and having a good characteristic while preventing damage of a punch and an ejector pin by allowing the outward expansion at the time of compressing a substrate metal layer to be released in a microrecess provided on a die through a cathode supporting tube. CONSTITUTION:A basic metal 33 of a cathode supporting tube 32 is made so that a part thereof for pressing in and fixing may form a microprojection part 36 together with a substrate metal 33 and a cathode sleeve 31 and in said micro- projection part 36 the cathode sleeve 31, the cathode supporting tube 32 and the substrate metal 33 are welded and fixed at a welding point 34 by resistance welding and laser welding and further an electron discharge substance layer 35 is formed by covering the top surface of the substrate metal 33. As to manufacture thereof, microrecesses (6 in the figure) (411) are axially provided on the part prepared facing to the substrate metal 33 of a die 41 so that a part of the substrate metal 33 expanding out at the time of compression of the substrate metal 33 may be released in the microrecesses (411) together with the cathode supporting tube 32 and the cathode sleeve 31.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing a cathode assembly, and more particularly to a cathode comprising a base metal L fitted on the inner wall near the top of a cathode support tube and both fixed by welding. This invention relates to a structure and its manufacturing method.

TECHNICAL BACKGROUND OF THE INVENTION A conventional cathode assembly (10), for example, as shown in FIG. The base metal (
3) and expand the cathode support tube (2) corresponding to the side wall of this base metal (3).
) and cathode sleeve (1) are brought into close contact, and the cathode sleeve (1), cathode support tube (2), and base metal (3
) is fixed, and then an electron emitting material layer (5) is formed on the top surface of the base metal (3).

Such a cathode structure is manufactured by a manufacturing method as shown in FIGS. 2 and 3.

That is, the eject turbine (
[Only the cathode sleeve (1) and cathode support tube (2) f
c Insert with the top facing down, and further insert the base metal (3) into this cathode support cylinder (2). Next, the first stopper 03
The cathode sleeve (1) is positioned by the second stopper I, and the cathode support tube (2) is positioned by the second stopper I7.Next, a punch (I!
At 19, the base metal (3) is compressed in the axial direction, and the base metal (3) is expanded in the radial direction, and the side wall of the base metal (3), the cathode support tube (2), and the cathode sleeve (1) are compressed. After the parts are brought into close contact with each other, they are removed from the manufacturing equipment and fixed by welding. In this case, one ejector turbine and one die (11
) has a circular cross section as shown in Figure 3, and the diameter of the ejector turbine a is approximately equal to the outer diameter of the cathode sleeve (1). ) will be constrained by die I.

Problems with the Background Art In this manufacturing method, the entire outer periphery of the cathode sleeve (1) is restrained by the die (11), so when compressing the base metal (3), the punch CI and the ejector According to experiments, a pressure of about 250 Kf is required for the base metal (3) with a diameter of 1.34w1φ, and due to this pressure, the pressure of the punch and ejector turbine Q is large. In many cases, the tip of a tool such as the
) is formed on the outside of the protrusion (31), and the punch +1
If the tip of 51 is damaged, the base metal (3) will break as shown in Figure 5.
A protrusion (32) is formed inwardly. This protrusion (31)
It is not possible to form the electron emitting material layer with a uniform thickness, and when the protrusion (32) is combined with the cathode heater, the insertion dimension varies, which affects the heating characteristics of the base metal (3). It has the disadvantage of being unstable.

In addition, the outer circumference of the cathode sleeve (1) is restrained all around by the die (11), and the base metal (3
) is press-fitted and expanded, the fitting force between the cathode sleeve (1) and the cathode support tube (2) and between the cathode support tube (2) and the base metal (3) is weak, making the positioning unstable. When welding the cathode sleeve (1), cathode support tube (2), and base metal (3), phenomena such as the base metal (3) tilting or coming off may occur, making stable welding impossible and causing defects after welding. There is a process of sorting, which has the disadvantage of increasing labor costs and decreasing yield.

Also, due to insufficient fitting force, when welding at the welding point (4), the surface of the base metal (3) and the end surfaces of the cathode sleeve (1) and cathode support tube (2) are not aligned. , there is a drawback that a misaligned portion (6) occurs and the heating characteristics of the cathode become unstable.

In addition, due to insufficient fitting force, when laser welding the welded part (4) as shown in Figures 7 and 8, there is a small gap (force, Support tube (2)
The l/- laser is irradiated with a small gap (8) formed between the sleeve and the cathode sleeve (1), and the partially welded one shown in Figure 7 or the one shown in Figure 8 It has the disadvantage of not being properly welded and resulting in poor perforation.

Furthermore, when forming an electron emitting material layer, as shown in FIG.
The cathode sleeve (1) is brought into contact with the tapered part (212) of the cathode and formed by spraying from the direction of the broken line arrow (2). In this case, as shown in Fig. 10, the diameter (φ1) of the spray area is Since it is proportional to the outer diameter (φ2) of the sleeve (1), if the outer diameter (φ2) is 1.39 mmφ, the diameter (φ2) is
l) has the disadvantage that the diameter of the effective electron emitting material layer is small, and the life characteristics after being incorporated into an electron tube are poor, with a diameter of about 1.20 mm.

Purpose of the Invention The present invention has been made in view of the various drawbacks of the conventional cathode structure and its manufacturing method described above. Firstly, it reduces the compression pressure of the base metal and prevents damage to the punch and ejector turbine.
To locally increase the close contact between the base metal and at least the cathode support tube, to prevent misalignment of both, to prevent defects in welding, and to prevent defects in positioning, and thirdly, to increase the diameter of the electron emitting material layer. It is an object of the present invention to provide a cathode structure that can have good life characteristics and a method for manufacturing the same.

Summary of the Invention In other words, the present invention has a cathode structure in which the base metal of the cathode support tube is inserted and the fixed portion is bulged together with the base metal to form a plurality of minute protrusions on the outside of the cathode support tube. This is a method for manufacturing this cathode structure.

Embodiment of the Invention Next, an embodiment of the cathode assembly of the present invention is shown in FIGS. 11 and 12.
This will be explained using figures.

That is, when inserting the cathode support tube (132 into the cathode sleeve C11) and press-fitting and fixing the base metal 03 to the inner wall near the top of the cathode support tube 021, the base metal (41) of the cathode support tube 03 is fixed. (to) is press-fitted so that the fixation part forms a minute protrusion (6 in the figure) with the base metal 0 moat and cathode sleeve G1), and resistance welding or laser welding is performed at the welding point 04) at this minute protrusion Weld and fix the cathode sleeve 01), the cathode old cylinder 0, and the base metal (C) by welding or the like 7, and then deposit G layers of electron emitting material on the top surface of the base metal (C) [7] It is characterized by

A cathode structure having such a structure is manufactured by a manufacturing method as shown in FIGS. 13 and 14.

That is, the eject turbine (
Insert the cathode sleeve cD and the cathode support tube (33 with the top downwards) onto the cathode support tube 43, and then insert the base metal 0 into this cathode support tube 02, and insert the first stopper (cathode sleeve 01 in 4 countries). , position the cathode support cylinder 03 with the second stopper (44).Next, the punch (4) placed coaxially with the ejector turbine (43) and the cathode support cylinder 03 Compressing in the axial direction is almost the same as in the conventional case, but in this example, the base metal (
Micro-grooves (6 locations in the figure) located opposite to (4)
1t) is provided along the axial direction, and the base metal (to)
A part of the base metal (c) that bulges out when compressed is allowed to escape into the minute recess (4b) together with the cathode support tube trowel and the cathode sleeve G1). This minute recess (411) has a width (W) of 0.00 mm when the outer diameter of the cathode support tube is 1.39 aφ.
2~03 The depth (T) is set to 0.1~0.2 mm, and the number is determined from the outer diameter of the cathode support tube, but the above-mentioned 1.39
In the case of +mφ, it is desirable to provide 6 to 8 locations.

According to the above-mentioned manufacturing method, between the four punches and the ejector turbine (43), there is a cathode sleeve (4υ) whose outer periphery covers the entire surface and is not constrained by the die (40, so about 20
The height of the protruding part of the cathode sleeve C11) becomes about 0.03 to 0.04 aφ with a pressure of about 9, and at this protruding part, the base metal (c), the area around the cathode support cylinder, and the cathode sleeve C31) are in close contact with each other, as shown in FIG. 15, even if welding is performed using a laser beam (41), as shown in FIG.
, the cathode support cylinder C3 side, and the cathode sleeve 0υ are extremely good. In addition, since the protrusion (to) serves as the position of the welding point 04), not only laser welding but also one of the two welding electrodes (471) (472) as shown in FIG. 472) in the direction of the arrow, it is also possible to rotate the cathode assembly (41) in the direction of the arrow, detect the protrusion (2), apply welding current at the position shown in the figure, and fix it.

In addition, the cathode structure of this example (41 has an electron emitting material layer in the 9th layer)
The tapered part of the spray chuck (21ρ
When forming by spraying from the direction of the dotted line arrow (2) by contacting the protrusion (to) of the cathode sleeve 0υ, the diameter becomes substantially larger due to the protrusion (to), so conventional Similarly, quad sleeve outer diameter (φ2) ”; e 1.3
When it is 9 m, the diameter (φ3) of the electron emitting material layer is 1.
It is possible to increase the length to 26 to 1.28 m, and the life characteristics after being incorporated into an electron tube are excellent.

Although the above embodiment describes a cathode assembly having a cathode sleeve, it is not limited to this, and for example, the 20th embodiment
Like the cathode assembly SOt shown in the figure, the cathode support cylinder (52)
and a cathode structure (60) shown in FIG. The cathode support tube (6) consists of a small diameter part (62+) and a large diameter part (622).
2) and a base metal (63), a welding point (64) is provided on the protrusion (66) of 1-1, and an electron emitting material layer (65) is coated. Effects of the Invention As described above, according to the cathode structure and the manufacturing method thereof of the present invention, the punch Although the punch and ejector turbine are often damaged when compressing the base metal, it is possible to obtain a cathode structure with good characteristics by reducing yield and labor costs due to sorting, and its industrial value is extremely high. .

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway elevational view showing an example of a conventional cathode structure;
FIG. 2 is an explanatory diagram showing a method for manufacturing the cathode structure shown in FIG. 1, and FIG. 3 is a cross-sectional view of FIG. 2 taken along line A-A.
4 to 8 are diagrams showing different failure states of cathode assemblies manufactured by conventional manufacturing methods, and FIG.
The figure is a cross-sectional view showing an external protrusion formed on the base metal, Figure 5 is a cross-sectional view showing an internal protrusion on the base metal, and Figure 6 is a partially cut-out ridge showing misalignment between the cathode sleeve and cathode support tube. 7 is a cross-sectional view of the main part showing the defective welding condition of the welding point,
Figure 8 is a cross-sectional view of the main part showing the state where the welding point is not welded,
Fig. 9 is a sectional view showing one step of spraying the electron emitting material, Fig. 10 is an elevational view showing the relationship between the outer diameter of the cathode sleeve and the diameter of the part coated with the electron emitting material, and Figs. FIG. 1 is a diagram showing an embodiment of a cathode structure of the invention and a method for manufacturing the same;
FIG. 11 is a partially cutaway elevational view showing one embodiment of the cathode structure of the present invention, and FIG. 12 is a cutaway view of FIG. 11 along line B-B.
, 7. FIG. 13 is an explanatory diagram showing a method of manufacturing the cathode structure of FIG. 11, and FIG. 14 is a cross-sectional view of FIG. 13 taken along line CC. 15 is an explanatory diagram showing a state in which a minute protrusion is being laser welded, FIG. 16 is an enlarged sectional view of the main part showing welding points, and FIG. 17 is a resistance welding state of a minute protrusion. FIG. 18 is a sectional view showing one step of spraying the electron emitting material, FIG. 19 is an elevational view showing the relationship between the outer diameter of the cathode sleeve and the diameter of the part coated with the electron emitting material, and FIG.
21 and 21 are partially cutaway elevational views showing different modifications of the cathode structure of the present invention. 1.31...Cathode sleeve 2,32,52.62.
・Cathode support tube 3.33, 53.63 ・Base metal
4.34, 54.64... Welding points 5.35, 55.
65...Electron emitting material layer 11.41...Die
12,42...Eject turbine 15.45
... Punch 24 ... Spray chuck 3
6.56.66...Minute protrusion 411...Minute groove 46...Laser 47 b47z...Welding electrode agent Patent attorney Inoue-Male Figure 2 Figure I Figure 3 Figure 4 Second
Figure 0Figure 21

Claims (2)

[Claims] (1) Cathode! In a cathode assembly comprising at least a support tube and a base metal press-fitted near the top of the cathode support tube, the base metal of the cathode support tube is press-fitted into a fixed portion, and the cathode support tube is expanded together with the base metal. A cathode assembly characterized by having a plurality of protruding minute protrusions. (2) A method for manufacturing a cathode assembly comprising at least a cathode support tube and a base metal to which the cathode support tube is press-fitted near the top, including the step of inserting the base metal near the top of the cathode support tube. , a step of placing the die on an ejector turbine that slides inside a die having a plurality of minute grooves formed along the axial direction on the inner surface opposite to the top portion; The method comprises a step of compressing the base metal using a moving punch and the ejector turbine, and the expansion of the base metal caused by the compressing step is released into the plurality of micro grooves together with the cathode support tube. A method for manufacturing a cathode structure characterized by: