JPH0817078B2 - Microwave tube electron gun assembly - Google Patents

Description

The present invention relates to an electron gun assembly of a microwave tube suitable for use in a microwave tube such as a traveling wave tube or a klystron.

(Prior Art) Generally, a microwave tube, for example, a traveling wave tube includes an electron gun structure, a slow wave circuit, and a collector. Conventionally, the electron gun structure is configured as shown in FIG. 1
Is a cathode electrode, 2 is a Wehnelt electrode, 3 is an anode electrode, 4 is an anode electrode flange, 5 is a support, 6a and 6b are cathode support cylinders, 7 is a cathode support cylinder flange, and 8a and 8b.
Is a heater, 9a and 9b are heater lead wires, 10 is an insulating spacer, 11 is a body portion, and 12, 13, and 14 are insulating cylinders that form an envelope.

(Problems to be Solved by the Invention) In the conventional electron gun assembly as described above, the cathode supporting cylinder 6b and the cathode supporting cylinder flange 7 are welded over the entire circumference of the point A at the time of manufacture to maintain vacuum tightness. However, the cathode shaft is apt to bend due to the distortion of the metal parts generated during the welding of the entire circumference. Further, it is structurally difficult to exhaust from the electron gun side.

Furthermore, the Wehnelt electrode 2 requires precise dimensions,
This dimension is subject to manufacturing variations, and even if manufactured in the same manner, the electron gun perveance is likely to be a traveling wave tube with various variations.

The present invention provides an electron gun assembly of a microwave tube which can prevent the relative position and size of the cathode electrode and the anode electrode from being distorted due to the stress strain of the metal during welding, and can reduce the variation of the electron gun perveance. To aim.

[Configuration of the Invention] (Means for Solving the Problems) According to the present invention, a cathode electrode, a Wehnelt electrode in front of the cathode electrode, and an anode electrode in front of the cathode electrode are sequentially arranged at predetermined intervals, and the cathode electrode is supported by a cathode support cylinder. , The cathode support cylinder is sandwiched between a plurality of insulating cylinders forming a vacuum envelope via a disk-shaped cathode support cylinder flange, and airtightly bonded and fixed. Further, the other side of the insulating cylinder opposite to the anode electrode. In an electron gun assembly of a microwave tube in which an auxiliary container member forming a vacuum region is joined to an end of an insulating cylinder located at, a through hole for ventilation is formed in a disk portion of a flange of a cathode supporting cylinder. A short cylinder portion extending along the tube axis direction is provided inside the position of the through hole, and the short cylinder portion and the cathode support cylinder are fitted together, and the fitting portions are provided at plural points in the circumferential direction. Welded Is connected, an electron gun assembly of further hermetic seal portion is provided in a part of the auxiliary container member microwave tube.

(Operation) According to the present invention, since the cathode support cylinder and the cathode support cylinder flange are connected by a plurality of spot welds,
It is difficult for the relative position and dimensions of the cathode electrode and the anode electrode to change due to the stress strain of the metal during welding. As a result, variations in electron gun perveance are also reduced.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

The microwave gun electron gun assembly according to the present invention is constructed as shown in FIG. 1, and the same parts as those in the conventional example (FIG. 8) are designated by the same reference numerals.

That is, a vacuum envelope is mainly composed of the insulating cylinders 12, 13, 14, and 15. In the vacuum envelope, the cathode electrode 1, the Wehnelt electrode 2, and the anode electrode 3 are sequentially arranged at predetermined intervals along the axis. It is arranged. The cathode electrode 1 is supported by the Wehnelt electrode 2 via the support 5 and also by the cathode support cylinders 6a and 6b. The cathode support cylinder 6b is fixed to a cathode support cylinder flange 7 having a through hole 16, and the cathode support cylinder flange 7 is clamped and fixed to insulating cylinders 13 and 14 constituting a vacuum envelope.

In the above case, the cathode supporting cylinder flange 7 is formed with a short cylindrical portion 7a which is bent at a right angle inside the through hole 16 for ventilation formed in the disc portion and extends along the tube axis direction. The cathode support cylinder 6b is fitted inside the cylindrical portion 7a. Then, the short cylindrical portion 7a of the cathode support cylinder flange 7 and the cathode support cylinder 6b are joined by spot welding at a plurality of positions in the circumferential direction at the tips of the fitting portions of the both, that is, at points B in the figure. There is. Therefore, the fitting portions of the two spot welded are not joined so as to keep vacuum tightness.

Further, the body portion 11 is attached to the end portion of the insulating cylinder 12. The anode electrode 3 is fixed to the anode electrode flange 4, and the anode electrode flange 4 is sandwiched and fixed to the insulating cylinders 12 and 13. Also, a heater is provided in the cathode electrode 1.
8a and 8b are provided, the heaters 8a and 8b are connected to the heater lead wires 9a and 9b, one heater lead wire 9a is connected to the cathode support tube 6a, and the other heater lead wire 9b is an insulating spacer. It is fixed to 10 and connected to a heater terminal cylinder 18 via a platinum ribbon 17. One end of the heater terminal cylinder 18 is clamped and fixed to the insulating cylinders 14 and 15,
The other end is connected to the exhaust pipe 19.

The other end of the heater terminal cylinder 18 and the exhaust pipe 19 are fixed by welding over the entire circumference and hermetically sealed. Therefore, a separate airtight sealing portion C is provided behind the fixed point B between the cathode support cylinder 6b and the cathode support cylinder flange 7 on the opposite side of the Wehnelt electrode 2.
It has two characteristics.

An auxiliary container member forming a vacuum region 20 is provided on the rear side of the welding point B opposite to the Wehnelt electrode 2. The auxiliary container member is for the insulating cylinders 13 and 14 and the heater terminals. The cylinder 18 and the exhaust pipe 19 are provided with the airtight sealing portion C on the entire circumference in a part of the auxiliary container member.

Further, a conductive getter 21 is arranged in the vacuum region 20, one end of which is fixed to the cathode support cylinder 6b and the other end thereof is fixed to the exhaust pipe 19. Reference numeral 22 in the figure denotes a through hole provided in the cathode support cylinder 6a.

According to this embodiment, the operator performing soldering or heli-arc does not need a mature technique. Also, since the gas is exhausted from the electron gun side, unevenness in the degree of vacuum is reduced, and as a result,
Changes in output power with time due to ion vibration are reduced. Further, there is no fear that the soldering portion and the heater lead wire are cut.

(Modification) FIGS. 2 to 7 show modifications of the present invention, and the same effects as those of the above embodiment can be obtained.

That is, in the case of FIGS. 2 to 7, a shield cylinder 23 is provided instead of the exhaust pipe 19 in the above embodiment, and the shield cylinder 23 and the heater terminal cylinder 18 are welded over the entire circumference. And is hermetically sealed. In the case of FIG. 2, no getter is provided.

In the case of FIG. 3, the getter 21 is arranged in the vacuum region 20 in the case of FIG. 2, one end of which is the cathode support cylinder.
It is fixed to 6b and the cathode support cylinder flange 7, and the other end is fixed to the shield cylinder 23.

In the case of FIG. 4, one end of the getter 21 in FIG. 3 is fixed to the cathode support tube 6b, and the other end is connected to the getter lead wire 24 penetrating the shield tube 23.

In the case of FIG. 5, both ends of the getter 21 arranged in the vacuum region 20 are fixed to the inner surface of the shield cylinder 23.

In the case of FIG. 6, one end of the getter 21 is fixed to the inner surface of the shield cylinder 23 in the case of FIG.
It is connected to a getter lead wire 24 passing through 23.

In the case of FIG. 7, a getter 21 is attached to the anode electrode flange 4.
Are fixed.

[Effect of the Invention] According to the present invention, since the cathode support cylinder and the cathode support cylinder flange are connected by a plurality of spot welds, the relative relationship between the cathode electrode and the anode electrode due to the stress strain of the metal during welding. Positional and dimensional deviation does not occur, and variations in electron gun perveance are reduced.

[Brief description of drawings]

1 is a sectional view showing an electron gun assembly of a microwave tube according to an embodiment of the present invention, FIGS. 2 to 7 are sectional views showing a modified example of the present invention, and FIG. 8 is a conventional microwave. It is sectional drawing which shows the electron gun structure of a tube. 1 ... Cathode electrode, 2 ... Wehnelt electrode, 3 ... Anode electrode, 6a, 6b ... Cathode support cylinder, 7 ... Cathode support cylinder flange, 18 ... Heater terminal cylinder, 19 ... Exhaust pipe, 20 …… Vacuum area, 21 …… Getter.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Junsuke Koma 72 Horikawa-cho, Saiwai-ku, Kawasaki-shi, Kanagawa Toshiba Electronic Device Engineering Co., Ltd. (56) References

Claims (1)

[Claims] 1. A cathode electrode, a Wehnelt electrode in front of the cathode electrode, and an anode electrode in front of the cathode electrode are sequentially arranged at a predetermined interval, and the cathode electrode is supported by a cathode support cylinder, and the cathode support cylinder is a disk-shaped cathode support. A vacuum flange is sandwiched between a plurality of insulating cylinders forming a vacuum envelope to be airtightly bonded and fixed, and a vacuum is applied to the end of the insulating cylinder located opposite to the anode electrode of the insulating cylinder. In an electron gun assembly of a microwave tube in which an auxiliary container member that constitutes an area is joined, a through hole for ventilation is formed in the disk portion of the cathode supporting cylinder flange, and the inside of the position of the through hole is formed. A short cylinder portion extending along the tube axis direction is provided, and the short cylinder portion and the cathode support cylinder are fitted together, and the fitting portion is connected by spot welding at a plurality of positions in the circumferential direction. Above supplement An electron gun assembly of a microwave tube, wherein an airtight sealing portion is provided in a part of the auxiliary container member.