JPH0210631A - Electron gun body structure for microwave tube - Google Patents

Abstract

PURPOSE:To prevent the size deviation due to the stress strain at the time of welding by point-welding a cathode support tube and a cathode support tube flange at multiple positions to connect and fix them, providing an auxiliary member constituting a vacuum area behind the opposite side to a Wehnelt electrode for these welded positions, and providing an airtight seal section on part of this member. CONSTITUTION:A vacuum envelope is constituted of insulating tubes 12-15, a cathode electrode 1, a Wehnelt electrode 2, an anode electrode 3 are provided in sequence along the axis of this envelope. The cathode electrode 1 is supported by the Wehnelt electrode 2 via a supporter 5 and supported by cathode support tubes 6a and 6b. The support tube 6b is fixed to a cathode support tube flange 7 having a through hole 16 by point welding at multiple positions B, the flange 7 is pinched and fixed by the insulating tubes 13 and 14. A separate airtight seal section C is provided behind the opposite side to the Wehnelt electrode 2 at the fixing positions B of the cathode support tube 6b and the support tube flange 7.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electron gun assembly for 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, has an electron gun structure,
Consisting of a slow wave circuit and a collector, the electron gun assembly has conventionally been constructed as shown in FIG. 8, where 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 body, 6a, 6b are cathode support tubes, 7 is a cathode support tube flange, 8a,
8b is the heater, 9a% 9b is the lead wire for the heater, 10
11 is an insulating spacer, 11 is a body portion, and 12, 13, and 14 are insulating cylinders forming an envelope.

(Problems to be Solved by the Invention) In the conventional electron gun assembly as described above, the cathode support tube 6b and the cathode support tube flange 7 are welded all around at point A during manufacture to maintain vacuum tightness.

However, the cathode shaft is likely to bend due to distortion of the metal parts that occurs when welding the entire circumference. Furthermore, it is structurally difficult to exhaust air from the electron gun side.

Furthermore, the Wehnelt electrode 2 requires precise dimensions, but these dimensions are likely to be subject to manufacturing variations, and even if manufactured in the same way, the electron gun perveance tends to be different in traveling wave tubes.

An object of the present invention is to provide an electron gun structure for a microwave tube that can prevent deviations in relative position and dimensions between a cathode electrode and an anode electrode due to metal stress distortion during welding, and reduce variations in electron gun perveance. purpose.

[Configuration of the Invention (Means for Solving the Problems) This invention provides a cathode support tube and a cathode support tube flange that are connected and fixed by spot welding at a plurality of locations,
Furthermore, an auxiliary container member forming a vacuum region is provided at the rear of the opposite side of the Wehnelt electrode with respect to the welding point, and a part of the auxiliary container member is provided with an airtight sealing part. It is.

(Function) According to this invention, since the cathode support tube and the cathode support tube flange are connected by a plurality of spot welds, the relative position and size of the cathode electrode and the anode electrode due to stress strain of the metal during welding It's hard to go crazy. As a result, variations in electron gun perveance are also reduced.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

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

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

In the above case, the cathode support tube 6b and the cathode support tube flange 7 are fixed by spot welding (edge arc welding) at a plurality of locations at point B, which is one of the features of the present invention.

Further, a body portion 11 is attached to an end of the insulating cylinder 12. The anode electrode 3 is fixed to an anode electrode flange 4, and this anode electrode flange 4 is connected to an insulating cylinder 12.
It is clamped and fixed to 13.

Further, heaters 8a and sb are provided in the cathode electrode 1, and the heaters 8a, s8b are connected to heater lead wires 9.
a, 9b, and one heater lead wire 9a is connected to the cathode support 1;? i6a, and the other heater lead wire 9b is fixed to an insulating spacer 10 and connected to a heater terminal cylinder 18 via a platinum ribbon 17. One end of this heater terminal cylinder 18 is connected to the insulating cylinder 1
4.15, and 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 hermetic sealing portion C is provided at the rear of the fixing point B between the cathode support tube 6b and the cathode support tube flange 7 on the opposite side from the Wehnelt electrode 2, which is another feature of the present invention. It has become.

Note that an auxiliary container member constituting the vacuum region 20 is provided at the rear on the opposite side of the Wehnelt electrode 2 with respect to the welding location at point B.
, a heater terminal cylinder 18, and an exhaust pipe 19, and a part of this auxiliary container member is provided with an airtight sealing portion C around the entire circumference.

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

According to this embodiment, it is not necessary for a single operator to perform soldering or edge arcing to have a sophisticated skill. In addition, since the electron gun is exhausted from the electron gun side, unevenness in the degree of vacuum is reduced, and as a result,
Changes in output power over time due to ion vibration are reduced. Furthermore, there is no possibility that the soldering part and the heater lead wire will be cut.

° (Modifications) Figures 2 to 7 show variations of this invention.
The same effects as in the above embodiment can be obtained.

That is, in the case of FIGS. 2 to 7, a shielding tube 23 is provided in place of the exhaust pipe 19 in the above embodiment,
This shielding cylinder 23 and the heater terminal cylinder 18 are fixed by welding over the entire circumference and hermetically sealed, and in the case of FIG. 2, no getter is provided.

In the case of FIG. 3, a getter 21 is arranged in the vacuum region 20 in the case of FIG. It is fixed.

In the case of FIG. 4, one end of the getter 21 in FIG. 3 is fixed to the cathode support cylinder 6b, and the other end is connected to a getter lead wire 24 passing through the shielding cylinder 23.

In the case of FIG. 5, the getter 21 disposed in the vacuum region 20
Both ends of the shielding cylinder 23 are fixed to the inner surface of the shielding cylinder 23.

In the case of FIG. 6, one end of the getter 21 is fixed to the inner surface of the shielding cylinder 23 in the case of FIG. 5, but the other end is connected to a getter lead wire 24 passing through the shielding cylinder 23.

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

[Effects of the Invention] According to the present invention, since the cathode support tube and the cathode support tube flange are connected by a plurality of spot welds, the relative relationship between the cathode electrode and the anode electrode due to stress distortion of the metal during welding is reduced. No errors in position or J-law occur,
Variations in electron gun perveance are reduced.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an electron gun assembly of a microwave tube according to an embodiment of the present invention, FIGS. 2 to 7 are cross-sectional views showing modified examples of the present invention, and FIG. FIG. 3 is a cross-sectional view showing a tube electron gun structure. 1... Cathode electrode, 2... Wehnelt electrode, 3...
...Anode electrode, 6a, 6b...Cathode support cylinder,
7... Cathode support cylinder flange, 18... Cylinder for heater terminal, 19... Exhaust pipe, 20... Vacuum region, 2
1... Getta. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure Figure 1

Claims (1)

[Claims] 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, and the cathode support cylinder supports a cathode support cylinder flange. In the electron gun assembly of the microwave tube, which is fixed to the envelope via a An electron gun assembly for a microwave tube, characterized in that an auxiliary container member forming a vacuum region is provided at the rear on the opposite side of the Wehnelt electrode, and a part of the auxiliary container member is provided with an airtight sealing part.