JPH08306320A - Collector of microwave tube - Google Patents

Abstract

PURPOSE: To prevent a break and a crack by relaxing a thermal stress generated in a joint part when the collector electrode of the collector of a microwave tube and an insulation vacuum envelope are hermetically sealed. CONSTITUTION: A corrugated metal member 2 is inserted and jointed between a collector electrode 1 and an insulation envelope 3. The corrugated metal member 2 is easily deformed and formed into structure having better heat conduction, thereby absorbing and relaxing a thermal stress generated in a joint part, so that a break and a crack can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collector of a beam straight type microwave tube.

[0002]

2. Description of the Related Art FIG. 6 is a vertical cross-sectional view showing the structure of a conventional beam rectilinear microwave tube, FIG. 7 is a vertical cross-sectional view of an embodiment of a conventional collector, and FIG. FIG. 10 is a transverse sectional view of a second embodiment of a conventional collector, FIG. 9B is a perspective view of FIG. 9A, and FIG.
(A) is a transverse sectional view of a fourth embodiment of a conventional collector, and (b) is a longitudinal sectional view of (a).

There are microwave tubes such as a traveling wave tube and a klystron for amplifying and oscillating microwaves by utilizing an electron beam for microwave relay stations and satellite communications.

As shown in FIG. 6, the beam rectilinear microwave tube includes an electron gun 57 for emitting an electron beam and an electron beam 5.
8 comprises a high frequency circuit 56 for interacting with the input microwave, a collector 50 for trapping the electron beam 58, and a beam focusing device 59 for focusing the electron beam 58.

An electron beam 58 emitted from an electron gun 57
Passes through the high frequency circuit 56, amplifies or oscillates the signal, and is captured by the collector 50. At this time, the electron beam 58 captured by the collector 50 converts the kinetic energy thereof into heat energy and raises the temperature of the collector electrode 51. Therefore, it is necessary to release the heat generated in the collector electrode 51 to the outside.

Further, in order to increase the efficiency of the microwave tube,
A method of lowering the collector potential is used. In this method, the potential applied to the collector electrode 51 is sequentially decreased with respect to the high frequency circuit 56, and the speed of the electron beam 58 impinging on the collector is decreased to reduce the heat energy generated in the collector electrode 51. For this reason, insulation between the collector 50 and the high-frequency circuit 56 is maintained by an insulator such as ceramics against high voltage.

As shown in FIG. 7, in the conventional collector structure of a straight beam type microwave tube, a collector electrode 51 made of copper, molybdenum, graphite or the like, a high ceramic for insulating the collector electrode 51 and keeping vacuum tightness. An insulating envelope 53, a support member 60 for supporting the collector electrode 51 and allowing the heat generated in the collector electrode 51 to escape to the outside through an insulating member, and an insulating member 54 for keeping insulation from the high frequency circuit. It Usually, these are joined to each other by a method such as brazing or welding.

In the above-described collector, due to the difference in thermal expansion coefficient between the insulating envelope 3 and the support member 11, thermal stress generated at the joint between the insulating envelope 3 and the support member 11 causes insulation. Of the joint between the conductive envelope 3 and the corrugated metal member 52 and the other supporting member 60 or the insulating envelope 5
3 cracks and cracks occur. Further, in the collector of this type, when the insulating envelope 53 also serves as vacuum airtightness, the generation of cracks or cracks leads to a fatal defect of the microwave tube. Therefore, in order to avoid such a problem, the corrugated metal member 52, which is a supporting member, is usually provided with a stress buffering mechanism, and a material having a good thermal conductivity is used to efficiently release heat to the outside.

In addition to these structures, particularly recently, cost reduction is required by a structure that is small, lightweight and easy to manufacture for communication or satellite tower mounting.

[0010]

As a method of solving this problem, as shown in FIGS. 8 (a) and 8 (b), Japanese Utility Model Laid-Open No. 60-85049 discloses a cylindrical collector outer circumference and a ceramic cylinder inner circumference. There is disclosed a technique in which a metal cylinder having a slit in the axial direction is interposed between the containers to prevent cracks due to thermal shock of the collector and to improve withstand voltage and heat resistance.

However, there is a drawback in that the manufacturing cost is high because a high level of machining is required to manufacture the slotted metal cylinder.

As a method of relieving the stress, as shown in FIG. 9, in Japanese Patent Laid-Open No. 2-117050, a diameter is provided between the insulating member on the envelope of the electron gun portion and the collector electrode and the outer frame support. There is disclosed a configuration in which stress buffering rings having elasticity that expands and contracts are alternately fitted and brought into contact with each other so as to connect to each other and thereby alleviate stress on the collector.

In this method, since the stress buffer rings having elasticity for reducing and expanding the diameter are alternately fitted and contacted,
If these are fixed by brazing or the like to maintain vacuum tightness, these functions are lost. Moreover, since the directions of elasticity are different, excessive stress is generated in the joint, leading to cracks and cracks in the insulating member.

Furthermore, Japanese Unexamined Patent Publication (Kokai) No. 63-284736 or the actual Kaihei 2-10145 shown in FIGS. 10 (a) and 10 (b).
Japanese Unexamined Patent Publication No. 4 (1998) discloses a structure in which the collector electrode is supported by a plurality of high thermal conductive cylindrical ceramics arranged between the collector electrode and the envelope, and the heat resistance is maintained while the earthquake resistance and shock resistance are improved. There is.

In this type of collector, the envelope, the collector electrode, and the highly heat-conductive cylindrical ceramics are pressed from the outside of the envelope by a method such as pressing to deform and fix the envelope. It is necessary to increase the mechanical strength of the plurality of high thermal conductivity ceramics arranged between the electrode and the envelope, which increases the weight of the collector.
For this reason, it is not suitable for applications where weight reduction is required, especially for applications such as mounting on satellites.

An object of the present invention is to have an excellent stress buffering mechanism and thermal conductivity by joining a corrugated metal part to the collector electrode and inserting and joining it between the collector ceramic envelope and the insulating ceramic envelope. It is an object of the present invention to provide a straight beam microwave tube collector having a lightweight and easy-to-manufacture structure.

[0017]

A collector of a microwave tube according to the present invention is a collector of a beam straight type microwave tube, wherein an outer peripheral surface of a cylindrical collector electrode and an inner peripheral surface of a cylindrical surrounding insulating member are provided. The corrugated metal thin plate is arranged in the entire circumferential direction of the cylindrical gap of, and the bottom and top of the corrugated metal thin plate are adhered to the outer peripheral surface of the collector electrode and the inner peripheral surface of the insulating member, respectively. Does the corrugated metal sheet have a flat portion in the circumferential direction so that the circumferential widths of the respective bonded portions of the bottom and the top of the thin plate occupy ⅕ or more of the pitch of the corrugations, respectively. Alternatively, it is characterized by having a portion along the circumferential surface of the bonding partner.

It is also desirable that the corrugated metal thin plate has a top portion, a bottom portion and an intermediate portion which are substantially flat.

The adjacent two forming the respective intermediate portions
It is also desirable that the surface be inclined in the same direction from one radial extension of the collector.

Further, the collector of the microwave tube is a cylindrical space between the inner peripheral surface of the cylindrical outer insulating member and the outer peripheral surface of the cylindrical collector electrode in the collector of the beam straight type microwave tube. Is bisected in the radial direction by a cylindrical intermediate insulating member, the first corrugated metal thin plate is arranged in the large-diameter gap portion, the second corrugated metal thin plate is arranged in the small-diameter gap portion, and at least the top portion of the first corrugated metal thin plate and It is also preferable that the bottom portions of the second corrugated metal sheets are bonded to the cylindrical surfaces facing each other.

[0021]

The collector of the present invention is relieved by easily deforming the structure of the corrugated metal thin plate inside the collector in response to the thermal stress generated at the joint portion, and is also heavier than the conventional type. It has the advantages of reduced thermal conductivity, good thermal conductivity, and common use of corrugated material.

[0022]

Embodiments of the present invention will now be described with reference to the drawings.

FIG. 1A is a longitudinal sectional view of an embodiment of the collector of the microwave tube of the present invention, FIG. 1B is a transverse sectional view taken along the line AA 'of FIG. 1A, and FIG. [Fig. 4] is a perspective view of the state in which the insulating envelope of (b) is removed.

The present embodiment is a collector of a beam straight type microwave tube, and includes a collector electrode 1, a corrugated metal thin plate 2,
It is composed of an insulating envelope.

The corrugated metal thin plate 2 is disposed over the entire circumferential region of the cylindrical gap between the outer peripheral surface of the cylindrical collector electrode 1 and the inner peripheral surface of the cylindrical insulating envelope 3.
Of the corrugated metal sheet 2 and the inner peripheral surface of the insulative envelope 3 are bonded to the bottom surface and the top surface of the corrugated metal sheet 2. So that the corrugated metal sheet 2 has a substantially flat name portion in the circumferential direction.

The materials and shapes of these constituent parts are as follows. Oxygen-free copper, molybdenum and graphite are used for the collector electrode 1, and the size thereof is 19 mm in outer diameter, 14 mm in inner diameter and 60 mm in length. The corrugated metal thin plate 2 is made of oxygen-free copper and has a plate thickness of 0, 2 mm and a height between the corrugation peaks and valleys of 3 mm.
Is. The insulating envelope 3 is a cylindrical alumina ceramic, and the size is an outer diameter of 30 mm, an inner shape of 26 mm, and a length of 65 m.
m.

The method for manufacturing and adhering the corrugated metal thin plate 2 will be briefly described. First, a square oxygen-free copper plate having a side of 500 mm is cut from a corrugated plate material in accordance with the outer circumference and length of the collector electrode 1, and this is cut. The corrugated metal thin plate 2 is wound with a gold brazing plate sandwiched between the corrugated metal thin plate 2 and the outer periphery of the collector electrode 1, and the gold brazing plate is further wound on the outer side of the corrugated metal thin plate 2 and arranged inside the insulating envelope 3. Brazing was carried out in a hydrogen flow of degree C.

At this time, the thermal stress generated in each joint due to the difference in the thermal expansion coefficient is absorbed and alleviated by the deformation of the corrugated metal thin plate 2 easily. As a result, there were no cracks or cracks in the three types of collector electrodes 1 of oxygen-free copper, molybdenum, and graphite and the insulating envelope 3.

Example 2 FIG. 2 is a cross-sectional view of a corrugated metal thin plate of a second example in which the curved top and bottom curved surfaces of the corrugated metal thin plate form a circumferential surface of 180 degrees or more.

In this embodiment, an insulating envelope 13 is provided on each of the top and bottom of the corrugated metal sheet 12 of the first embodiment.
The bonding area with the collector electrode 11 (not shown) (not shown) is large, and the area of the intermediate portion is also large. This has the advantage that the heat transfer effect is large, but on the other hand, the time required to produce the corrugations increases slightly.

Example 3 FIG. 3 (a) is a cross sectional view of a third example in which the corrugated metal sheet has corrugated tops, bottoms and intermediate portions which are substantially flat, and FIG. 3 (b) is It is a perspective view of the state where the insulating envelope of (a) was removed.

This embodiment is almost the same as the first embodiment in the material, shape and manufacturing method of the parts, but only the shape of the corrugated metal thin plate 22 is different. That is, in the case of the present embodiment, as shown in FIG. 3B, the flat portion 22a is formed at each of the top portion, the bottom portion and the intermediate portion.
In the case of this example, the heat transfer area was increased as compared with the first example, so the thermal conductivity was improved by 5 to 10%.

Fourth Embodiment FIG. 4 shows that the corrugated metal sheet has corrugated tops, bottoms and middle portions which are substantially flat, and the middle surfaces are inclined in the same direction with respect to the radial direction of the collector. It is a cross-sectional view of the corrugated metal sheet of the fourth embodiment.

Compared to the third embodiment, this embodiment further increases the bonding area of the corrugated metal thin plate 32, and the thermal stress causes an insulating envelope 33 (not shown) and a collector electrode 31 (not shown). In order to alleviate the influence on the radial direction by the shift in the circumferential direction, the intermediate portion is inclined in the same direction with respect to the radial direction.

About the Fifth Embodiment FIG. 5A shows a first corrugated metal thin plate in a cylindrical space.
FIG. 5B is a vertical sectional view of the fifth embodiment in which the intermediate insulating member and the second corrugated metal thin plate are arranged, and FIG.

The present embodiment is different from the first to fourth embodiments in that the corrugated metal thin plate 42 has two stages, that is, the first and second corrugated metal sheets 42, to make the heat conduction large and gentle. However, this application is limited to special cases because it increases the cost.

[0037]

As described above, according to the present invention, the thermal stress generated at the joint portion of the corrugated metal thin plates inside the collector is mitigated by the easy deformation of the corrugated metal thin plates, and the adoption of the corrugation makes it possible to reduce the thermal stress by about 30 times. %, And by adopting a metal with high thermal conductivity such as oxygen-free copper, high thermal conductivity can be maintained despite weight reduction. Moreover, the corrugated metal member has a large collector electrode size. Since it can be cut and wound around the outer circumference of the collector electrode in accordance with this, it is possible to provide a microwave tube collector having various advantages that the members can be made common and contribute to cost reduction.

[Brief description of drawings]

1A is a vertical cross-sectional view of an embodiment of a collector of a microwave tube of the present invention, FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG. 1A, and FIG. It is a perspective view of the state where the insulating envelope of b) was removed.

FIG. 2 is a transverse cross-sectional view of a corrugated metal thin plate of a second embodiment in which the curved top and bottom curved surfaces of the corrugated metal thin plate form a circumferential surface of 180 degrees or more.

FIG. 3 (a) is a cross-sectional view of a third embodiment in which the corrugated metal sheet has corrugated tops, bottoms, and intermediate portions forming substantially flat surfaces, and FIG. 3 (b) is an insulating outer layer of FIG. 3 (a). It is a perspective view in the state where the enclosure was removed.

FIG. 4 is a waveform according to a fourth embodiment in which the corrugated metal sheet has corrugated tops, bottoms, and middle portions each forming a substantially flat surface, and the middle surfaces are inclined in the same direction with respect to the radial direction of the collector. It is a cross-sectional view of a thin metal plate.

FIG. 5 (a) is a first corrugated metal thin plate in a cylindrical space,
FIG. 5B is a vertical sectional view of the fifth embodiment in which the intermediate insulating member and the second corrugated metal thin plate are arranged, and FIG.

FIG. 6 is a vertical cross-sectional view showing the configuration of a conventional beam rectilinear microwave tube.

FIG. 7 is a vertical cross-sectional view of an example of a conventional collector.

8A is a cross-sectional view of a second embodiment of a conventional collector, and FIG. 8B is a perspective view of FIG. 8A.

FIG. 9 is a vertical cross-sectional view of a third embodiment of a conventional collector.

FIG. 10A is a transverse sectional view of a fourth embodiment of a conventional collector, and FIG. 10B is a vertical sectional view of FIG. 10A.

[Explanation of symbols]

 1, 21, 41 collector electrode 2, 12, 22, 32, 42 corrugated metal thin plate 3, 23 insulating envelope 5 collector terminal 41a collector core 43 vacuum envelope 44 intermediate insulating member (ceramics) 50 collector 51, 61 , 71, 81 Collector electrode 52 Corrugated metal thin plate 53 Insulating envelope 54, 73, 74 Insulating member 55 Collector terminal 56 High frequency circuit 57 Electron gun 58 Electron beam 59 Beam focusing device 60 Supporting member 68 Groove 72 Spare -Support 75 Filling resin 76 Support medium structure 76a, 76b Stress buffer ring 77a, 77b Outer frame support 81a Annular convex portion 82 Cylindrical ceramic 87 Enclosure

Claims (4)

[Claims] 1. In a collector of a beam straight-forward microwave tube, a corrugated metal thin plate is provided in the entire circumferential direction of a cylindrical gap between the outer peripheral surface of a cylindrical collector electrode and the inner peripheral surface of a cylindrical outer insulating member. The bottom and top portions of the corrugated metal thin plate are respectively adhered to the outer peripheral surface of the collector electrode and the inner peripheral surface of the insulating member, and the bottom and top portions of the corrugated metal thin plate are respectively bonded. The circumferential width of the bonded portion is 1/5 of the pitch of the corrugations.
As described above, the portion of the corrugated metal sheet has a flat portion in the circumferential direction or has a portion along the circumferential surface of the bonding partner, the collector of the microwave tube. 2. The collector of the microwave tube according to claim 1, wherein the corrugations of the corrugated thin metal plate have a top portion, a bottom portion and an intermediate portion which are substantially flat. 3. Two adjacent surfaces forming each of the intermediate portions are:
The microwave tube collector according to claim 1 or 2, wherein the collector is inclined in the same direction from a radial extension line of the collector. 4. In the collector of a straight beam type microwave tube, a cylindrical space between an inner peripheral surface of a cylindrical outer insulating member and an outer peripheral surface of a cylindrical collector electrode is a cylindrical intermediate insulating member. The first corrugated metal thin plate is divided into two parts in the radial direction, the first corrugated metal thin plate is arranged in the large-diameter gap part, and the second corrugated metal thin plate is arranged in the small-diameter gap part, and at least the top part of the first corrugated metal thin plate and the second corrugated metal thin plate.
The collector of the microwave tube in which the bottoms of the corrugated thin metal plates are adhered to the cylindrical surfaces facing each other.