JPH0456041A - Traveling wave tube and manufacture thereof - Google Patents

Abstract

PURPOSE:To minimize thermal deformation due to local hot beam irradiation of the brazing part by furnishing a large wall thickness part for suppression of thermal deformation at a flange to be connected with a metal envelope which accommodates a helix coil. CONSTITUTION:A flange plate 31 is composed of a circular flat plate part 34 of for ex. 1.5mm thick and a dam-shaped large wall thickness part 35 which is provided protrusively in the circumferential direction on the main surface on the junction 33 side of this flat plate part 34. The junction 33 is put in coaxial contact with one end of the metal envelope 5 through a brazing material 41, and the brazing part is irradiated with a beam of light 42 emitted by an optical welding machine located on the electron gun side of the flange plate 31 so as to melt the brazing material 41 followed by cooling, and thus the metal envelope 5 is brazed fast to the flange 13. With irradiation with the beam of light 42 the flange plate 31 is heated and thermally expanded, but thermal deformation due thereto can be suppresses to possible minimum by large wall thickness part 35....

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a spiral traveling wave tube and a method for manufacturing the same.

(Prior art) The operating principle of a traveling wave tube is that, as shown in Fig. 11, the electron flow (81) emitted from an electron gun (^) in a vacuum moves along the slow wave circuit fC1 axis, traveling in the same direction. The microwave is amplified using the interaction that occurs between the electric field on the axis and the electrons when the velocity of the radio wave is approximately equal to the velocity of the radio wave.The electron flow finally passes through the collector (collecting electrode). It is collected in (D).

The features of this traveling wave tube are that the slow wave circuit (C) has a large number of waves on the axis, which increases the interaction with electrons and provides high gain, and there are few places where energy accumulates in the circuit, so
The amplification bandwidth is wide. Therefore, an attenuator (El) is used to prevent unnecessary reflected waves occurring somewhere in a wide bandwidth. Also, as shown in FIG. F), a metal envelope (G) coaxially surrounding and housing this helix coil (F), and a metal envelope (G) interposed between this metal envelope (G) and the helix coil (1'), for example. Bereria support rod (H)... and these support rods (II)
... to the helix coil (F) (
”)... In addition, a metal envelope (G
) is connected to the electron gun (
It is connected to a cylindrical storage body that stores ^). The flange (L) is arranged to extend in the axial direction on a circular plate-shaped flange plate (Ll) having a thickness of, for example, 1.5 mm, and on the peripheral edge of one main surface side of this flange plate (Ll). Ring part (Ll)
and a connecting portion (L3) having the same diameter as the metal envelope (G) coaxially protruding from the peripheral edge of the other main surface of the flange plate (Ll).

By the way, the flange fL) is coaxially connected to the metal envelope fG) via a brazing material part (N). In this case, the brazing between the 7 flange fL) and the metal envelope (G) is as shown in Figure 13.
With the metal envelope (G) in coaxial contact with L3) through the brazing material, the light beam (Q) from the optical welding machine is applied.
from the ring part (Ll) side of the 7 flange (Ll), and the connecting part (
This is done by irradiating the abutment area between L3) and the metal envelope (G) to locally heat it, melting the brazing filler metal, and then cooling the melted brazing filler metal.

(Problem to be solved by the invention) However, the light beam from the conventional optical welding machine (Ql
The flange (L) and metal envelope (Gl
When the flange (L) is brazed, the flange plate (L) becomes (Ll).
is extremely thin, causing thermal deformation. As a result, the straightness and concentricity of the electron gun (Al) and the metal envelope (G) deteriorate, the electron beam transmittance into the helix coil (F) decreases, and the characteristics of the traveling wave tube deteriorate. It has the disadvantage of being

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a traveling wave tube and a method for manufacturing the same that can solve the above problems.

[Structure of the Invention] Means and Effects for Solving Problem 1) The traveling wave tube and the manufacturing method thereof of the present invention include a flange connected to a metal envelope housing a helix coil to prevent thermal deformation. This thick part can minimize thermal deformation caused by localized heat beam irradiation on the brazing material. Therefore, the metal envelope and the flange can be brazed with high precision and good reproducibility.

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

1 and 2 show the traveling wave tube of this embodiment. This traveling wave tube consists of an electron gun section (2) that emits an electron stream (1), and a microwave that is coaxially connected to this electron gun section (2) and amplifies microwaves by introducing the electron stream (1). It consists of a wave amplification section (3) and a collector section (4) that collects the electron flow (1) that has passed through the microwave amplification section (3). Therefore, the microwave amplifying section (3) includes a cylindrical metal envelope (5) and a cylindrical metal envelope (5), which is fixed to the inner wall of the metal envelope (5) by, for example, press-fitting or brazing. Cylindrical support rod (6) made of beryllia, etc., which has good thermal conductivity
..., a helix fill (7) made of molybdenum (Mo), etc., supported coaxially inside the metal envelope (5) by these support rods (6), and (
(see Figure 3), this helix coil (7) and support rod (
6) The brazing material part (8) to be brazed with... and the annular magnet (11) wound around the outer periphery of the metal envelope (5).
and input/output connectors (+21) protruding from both ends of the metal envelope (5). It consists of a connected flange (13) and a flange (14) coaxially connected to the end of the metal envelope (5) on the collector part (4) side.The wax part (8) ...The material of the brazing filler metal is an alloy of Ti, Zr, etc., which are very active metals, and Ni5Cu, Ag, which form an alloy with a relatively low melting point, so that it has a eutectic composition. Further, the electron gun section (2
The flange (13) on the side of The electron gun section (2
) and a metal envelope (5) coaxially protruding from the center of the other main surface side of the collar plate (31).
There is a connecting portion (33) having the same diameter as the metal envelope (5) and brazed to the metal envelope (5) by a method described later. This connection part (33) allows the electron flow (1) to pass from the electron gun part (2) to the microwave amplification part (3)! ! Road hole 331
) is drilled. Therefore, the flange plate (31) includes a circular flat plate part (34) having a thickness of, for example, 1.5 mm, and a main surface of this flat plate part (34) on the connecting part (33) side, which protrudes in the circumferential direction. It consists of a thick walled part (35) in the shape of a dam.

Next, a method for manufacturing the traveling wave tube having the above configuration will be described.

First, the method for manufacturing the slow wave circuit for traveling wave tubes of this example is as follows:
As shown in Fig. 6, the first step is to securely secure the support rods (6) by equally distributing them around the helix coil (7) through the wax portions (8); Support rod (6) to which the helix coil (7) is integrally fixed after one step
... to the metal envelope (5) by, for example, press-fitting or brazing, and after this second process, the input/output connectors (+2) and (+2) are connected to the metal envelope. (5), and after this third step, the metal envelope (5) is brazed.
) and the flange (+31. (+41)
step, and after this fourth step, each flange (131, (+4
) to the electron gun part (2) and collector part (4), respectively.

Therefore, in brazing the metal envelope (5) and the flange (13) in the fourth step, as shown in FIG. Niwaza wood (4
1) and the 48th step of coaxially abutting the
After step A, the brazing area is irradiated with a light beam (42) emitted from a light welding machine (not shown) installed on the electron gun part (2) side of the collar plate (31) to melt the brazing material (41). It consists of a 4th B step of cooling and brazing the metal envelope (5) and the flange (13). The material for the brazing filler metal (41) is made by alloying Ti, Zr, etc., which are very active metals, with Ni, Cu, and Ag, which form alloys with relatively low melting points, to form a eutectic composition. Use the converted one. Therefore, in the fourth B step, the light beam (42)
When the flange plate (31) is irradiated with irradiation, the flange plate (31) is heated and thermally expands, but the thermal deformation caused by this can be suppressed to a minimum by the thick portion (35).

As mentioned above, in this embodiment, the flange (13
) is provided with a thick wall part (35) to suppress thermal deformation, so that thermal deformation caused by the light beam (42) can be suppressed to a minimum. 13
) can be brazed with high precision and good reproducibility. As a result, electron gun 1? B (21 and metal envelope (5)
), the straightness and concentricity with the helix coil (7
), which greatly contributes to improving the characteristics of the traveling wave tube.

Note that the thick portion (36) may be a combination of a radial portion (361) and a concentric portion (36b), as shown in FIG. In addition, as shown in FIG.
7)... may be provided in a grid pattern. Furthermore, as shown in FIG. 10, rectangular thick-walled portions (38) may be provided radially on the main surface of the connection side of the flat plate portion (34).

Furthermore, other heat beams such as a laser beam or an electron beam may be used as a heat source for the metal envelope (5) and the flange (13). Furthermore, the heat beam is not limited to being irradiated from the electron gun section (2) side, but may be irradiated to the brazed region from an optical welding machine provided on the side of the metal envelope (5).

[Effects of the Invention] The traveling wave tube and the manufacturing method thereof of the present invention provide a thick wall portion on the flange connected to the metal envelope housing the helix coil to prevent thermal deformation, so that brazing is not possible. Thermal deformation caused by local heat beam irradiation to the site can be suppressed to a minimum.

Therefore, the metal envelope and the flange can be brazed with high precision and good reproducibility. As a result, the straightness and concentricity between the electron gun and the metal envelope are improved, and the electron beam transmittance into the helix coil is increased, which greatly contributes to improving the characteristics of the traveling wave tube.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the configuration of a traveling wave tube according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the main part, FIG. 3 is a diagram showing a helix coil, and the fourth FI! J is a plan view of the flange, FIG. 5 is a sectional view taken along the line ■-V in FIG. 4, and FIGS. 6 and 7 are explanatory diagrams of a traveling wave tube manufacturing method according to an embodiment of the present invention. , FIGS. 8 to 10 are explanatory views of traveling wave tubes according to other embodiments of the present invention, and FIGS. 11 to 13 are explanatory views of prior art. (1): Electron flow, (2): Electron gun section, (5
) : Metal envelope, (6) : Support rod, (
? ): Helix coil. (+3): Flange, (35), (36), (37
), (3g): Thick walled part. Fig. Rod Diagram / 2 Electric: + Koshu, 7 Hezo γ7 Scoil Rod δ Fig. Rod Fig. Z

Claims (2)

[Claims] (1) A cylindrical metal envelope, a plurality of support rods fixed to the inner wall of the metal envelope in an evenly distributed manner so that the longitudinal direction becomes the axial direction, and a metal outer enclosure using these support rods. a helical helix coil coaxially fixed inside the helix coil, an electron gun that emits an electron current into the helix coil, and a metal envelope inserted between the electron gun and the metal envelope. 1. A traveling wave tube comprising a flange for connecting to a metal envelope, characterized in that the flange is provided with a thick walled portion for preventing thermal deformation. (2) A cylindrical metal envelope, a plurality of support rods fixed to the inner wall of the metal envelope in an evenly distributed manner so that the longitudinal direction is the axial direction, and these support rods are used to surround the metal envelope. a helical helical coil fixed coaxially inside the electron gun, and a flange inserted between the electron gun and the metal envelope to connect the electron gun and the metal envelope. A method for manufacturing a wave tube includes a first step of coaxially abutting the flange provided with a thick wall portion for preventing thermal deformation to one end of the metal envelope via a brazing material; A method for manufacturing a traveling wave tube, comprising, after the first step, a second step of brazing by irradiating a heat beam to the contact portion of the flange to the metal envelope.