JPS62122027A - Structure of ceramic airtight connection for electron tube - Google Patents

Abstract

PURPOSE:To realize a safety operation, by short-circuit contacting electrically the first sealing metal ring to a metallic support plate in the vacuum area side, and screening the space including a spacer ring from the high frequency waves in the inner space of a ceramic cylindrical body. CONSTITUTION:When the inside obtains a vacuum condition, the atmospheric pressure presses strongly a ceramic cylinder 20 and the bent end 26b of the first sealing metal ring 26 to the surface of a metallic support plate 21 to maintain a secure electrical contact. The high frequency current in the operation flows only on the upper side of the first sealing metal ring 26, and scarcely flows on the rear side, that is, the metallic member surfaces in a space S including a spacer ring 27. Therefore, no high frequency discharge will occur at the inner side contact of a weld A between the first and the second sealing metals 26 and 28. Also no high frequency current flows at the soldered part B between the first sealing ring 26 and a ceramic spacer ring 27. Therefore, a possibility of making damage at the soldered part is also eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement in a ceramic hermetic joint structure of an electron tube.

[Technical background of the invention and its problems] For example, high power multi-cavity crystro/, traveling wave tube, gyro rono, Daido kamadai tron, high power transmitting tube Oyo 1 Koran technique electronic C-koha , they have O'4 consignment part, common ~ empty man part, 4-pole samurai pipe, high guard & output part, etc. 1, and have a ceramic circle body, a metal support plate, and ζ vent joints. Such ceramic cylindrical bodies are often installed in areas that are insulated from high voltages or areas through which high-frequency or high-wave power can pass. The high-frequency output section of a high-power multi-aircraft klystron conventionally has a structure as shown in FIG.

12.13 is the drift tube, 14Fi empty g4 wall.

15i't part I/kuta part, 17ri output 41! 1 & circuit, 18 is its inner conductor, 18M is the tip of the inner ring, 18b is the loop joint, 19 is the outer conductor, 20 is the ceramic cylinder, and 2122 is hermetically sealed to both open ends of this ceramic cylinder. Synthetic fiber support plate.

Reference numerals 23 and 24 designate airtight joints between the ceramic cylindrical body and the gold support plate, and 25 designates a rod-shaped wave tube. In this way, the high frequency is converted from the output coaxial line to the rectangular waveguide and used.

Now, in the air-tight joint, as shown in an enlarged view of one side, the first thin-walled JI gold-reducing ring 26 is air-tightly soldered at the soldering part B, and It is folded back into a letter shape and the other end is extended outward iC. A flattening ring 27 made of the same ceramic material and commonly called a backup ring is soldered and fixed to the back surface of the first sealing metal ring 26. The back surface of this slider/g 27 is held in an annular recess 21aK formed in the gold support plate 21.

Annular recess 21 of metal support plate! A second sealing ring 28 made of thin metal is hermetically soldered to the outer side of the tube. The first and @22 sealing metal rings 26 and 28 are partially flush with each other, and their outer circumferential tips on the atmosphere side are arc welded as indicated by the reference numeral 1. Note that a discharge prevention ring 29 is fixed to the inner part of the annular recess 211 of the metal support plate, and a discharge prevention ring 30 is also fixed to the four waves 25. And they are connected by a fixing flange 31.

These metal support plates 21. 1st. Second sealing ring 26.2
8. The ceramic cylindrical body 20 maintains airtightness. The first sealing ring 26 and the ceramic cylindrical body 20 are bonded to each other. ! It has the function of relieving stress and protecting the area.

By the way, in the operation of Mike A Yoshirai, Takago & iE Dai flow as shown by the arrow near this airtight joint. The problem here is the first one. Since the inner surfaces of the welded portions of the second sealing rings 26 and 28 meet each other at a small distance, high FIJ wave discharge is likely to occur in this portion. This is hardly a problem when the power of the high 8 technique is relatively small, but it becomes a problem that cannot be ignored in the case of high-power micro and snow machines with hundreds of kilowatts and 9J. If electrical discharge occurs in such a portion, local heat generation in the sealing ring may damage the soldered portion between the sealing ring and the ceramic cylinder.

This rapid bonding process and the phenomena caused by it are related to the metal support plate of an external air-drawn type pottery as disclosed in, for example, Japanese Utility Model Application Publication No. 59-16057. A similar phenomenon may occur at the soldered joint with the ceramic cylinder.

[Purpose of the invention]

The present invention solves the above-mentioned disadvantages, and provides a ceramic cylinder for a high-frequency electron tube that more reliably suppresses high-frequency discharge at the hermetic joint between the ceramic cylinder and the metal support plate even in high-power operation, and is expected to operate stably. This provides an airtight joint structure.

・[Lag of the invention] This FP1 consists of a ceramic cylinder that is hermetically sealed to a gold support plate and transmits high frequencies, a No. 1011 metal ring that is hermetically soldered to its surface, and a metal ring that is soldered to its back surface. and a second sealing metal ring, which is hermetically joined to the metal supporting plate and partially faces the first sealing metal ring and is hermetically joined on the atmosphere side. 1 Sealing metal 1j is attached to the metal support plate on the vacuum @ area side.
There is an airtight joint part 16 which is electrically short-circuited and insulates the space containing the switch and the gas from the inner space of the ceramic cylinder body at high frequency. Then, the metal support plate and the ceramic cylindrical body are joined together, and the inner surfaces of the plurality of sealing rings, which are partially face-to-face and joined together on the atmosphere side, are bonded together. There is no false cycle flow between them, and the risk of high frequency discharge occurring there is eliminated. Therefore, it is expected to be stable and have a high level of movement.

Examples of debunked inventions] An example of its fruition will be explained with reference to the drawing below.

Note that the same part Filit)-sign is used.

The fruit shown in Figure 1! ! This example is applied to the airtight joint B23, 24 between the ceramic cylindrical body 20 and a disk-shaped metal support plate fixed to the outer conductor end of the output coaxial line 17. As shown in the enlarged view of one of them, the first sealing ring 6 has a ceramic cylindrical body 2o and a back-up ceramic spacer ring 27 of the same quality soldered to both sides at a soldering part B. On the circumferential side, that is, on the inside of the laminated cylindrical body, it is bent in a cylindrical shape and sealed. This inner list form 26a ・Has Sue ξ-Sari/G 270 inner W surface t~・Ha, -! bent end 2 of l-
6b is extended to the back surface of the slider/g 27.

Then, it is brought into contact with the surface of the four-shaped concave portion 21a of the i-immersion temporary 21. Also, on this U-shaped inner circumferential portion 26, there are a number of slots 7) 26c parallel to the tube axis direction. This provides good electrical contact with the air vent and the metal support plate for exhausting the exhaust gas 27 and its outer peripheral space S to the IK air. In addition, this pickpocket 7) 26c almost eliminates the electromagnetic field of the operating fundamental frequency! 3! It has a cut-off dimension that is not suitable for use.

Due to this beak structure, when the inside is in a vacuum state, the ceramic cylinder and the first sealing metal ring 26 are damaged by atmospheric pressure.
The bent end 26b of is pressed strongly against the surface of the metal support plate to maintain reliable electrical contact. And the high frequency current during operation.

As shown by the arrow, the first arriving money flows only on the top side of the shoes 6,
There is almost no flow on the surface of each metal member in the space S on the 1& surface side, that is, the space S where the subere ring is present.

Therefore, there is no risk of high frequency discharge occurring at the inner surface matching portion of the welded portion A of the first and second sealing metal rings. Further, since no current flows through the high circumference 1 through the soldered portion between the first sealing ring 6 and the ceramic ring 27, the fear of damage to this soldered portion is also eliminated.

In this structure, the first sealing metal ring 6 is first
As shown in Fig. g2, form the slit 7 26c and bend it to the 0th order, as shown in Fig. 3. Fix with K soldering. Then, as shown in FIGS. 4 and 5, the inner circumferential end 26b of the sealing metal ring is bent to the back side of the spacer ring 27. Note that the spacer ring may be soldered to the sealing metal ring 26 by bending its inner peripheral portion into a cone shape as shown in FIG. 4. After configuring in this way, the open end surface of the ceramic cylindrical body 20 is soldered to the flat upper surface of the first sealing metal 141J ring 26.

On the other hand, the 2nd i1@metal ring 28 is soldered to the metal support plate, and these are combined and the outside air tilted part of the facing part of both arrival metal rings is edge arc welded around the entire circumference. Have self-exchange air contact.

In this way, the joint is completed.

In the example shown in FIG. 6, an inverted U-shaped portion 26d is formed on the inner peripheral portion of the first sealing ring 6. Thereby, high frequency fatigue inside the ceramic cylindrical body 2o can be completely prevented.

! In the ninth example shown in FIG. 7, a spring force acting in the direction of the arrow P is applied to the inner part of the 114th metal fitting ring 6 to FS 26 a, and this inner peripheral surface is connected to the inner wall surface of the recess of the metal support plate 21. It is press-fitted to make electrical contact. This cusp
'bAccording to NK, the parts processing power is easy;
It is possible to obtain the same anti-release effect as fft.

Note that the portion where the circumferential portion of the first sealing metal ring is brought into air contact with the metal support plate 1ct may be joined to the metal support plate 1 ct airtightly and to Pi' by brazing or the like.

〔Effect of the invention〕

Explanation above 1-t;
Combine the Kintsuta support plate and the 4 Ramipuku bodies 5
As a result, the high-frequency limb electric power does not flow between the inner surfaces of the F-coat of the number of fils that were connected on the weather side because the two parts could not meet, and the high-frequency electric current did not flow between the inner surfaces of the two sides. There is no risk of this occurring.Therefore, it is stable and allows highly axial movement.

4 r+J'111i Explanation of Drawings FIG. 1 is a longitudinal cross-sectional view of essential parts showing one embodiment of the present invention,
Figures to Figures 5 are semi-longitudinal, cross-sectional, and bottom views of part q1 showing the parts assembly procedure, and Figures 6 and IR7 respectively show the main parts of nine other examples of the present invention! FIG. 8 is a vertical cross-sectional view of a main part showing a conventional structure.

20...Ceramic cylindrical body, 21...Metal support plate, 2
3.24...Aerial joint, 26...First arriving metal I
J Ng, 27...Sweet ring, 28...Second
Spring gold A/G, 26c...slit, person...welding part.

B...Brazing part.

Izuho's agent Patent attorney Takeshi Suzue 5th Figure 1 Figure 2 Figure 3 m 4 Figure 5 Figure 1!7 Figure

Claims (3)

[Claims] (1) A metal support plate through which a high-frequency current flows; a ceramic cylinder that is hermetically sealed to the metal support plate and transmits high-frequency waves;
A first sealing metal ring made of a thin metal is hermetically soldered to the open end surface of the ceramic cylinder; A ceramic spacer ring is mechanically held on a part of the support plate, and an outer peripheral side of this spacer ring is hermetically joined to the metal support plate, and a part of the spacer ring is flush with the first sealing metal ring, and is on the atmosphere side. In the ceramic hermetic joint structure of an electron tube, the first sealing metal ring is hermetically soldered to the ceramic cylinder, and the first sealing metal ring is hermetically soldered to the ceramic cylinder, and the first sealing metal ring is hermetically soldered to the ceramic cylinder. A ceramic hermetic joint structure for an electron tube, characterized in that the space including the spacer ring is electrically short-circuited to the metal support plate and is shielded from the inner space of the ceramic cylinder at high frequencies. (2) The first sealing metal ring covers the inner peripheral surface of the spacer ring, extends to the bottom surface, and is electrically contacted with the metal support plate surface. Airtight joint structure. (3) A ceramic hermetic joint structure for an electron tube according to claim 1, wherein the first sealing metal ring has a plurality of slits formed in a portion that is electrically contacted with the metal support plate.