JP2862970B2 - Spiral circuit assembly jig for traveling wave tube and spiral circuit assembly method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for assembling a spiral circuit and a method for assembling a spiral circuit used when assembling a traveling wave tube by inserting a helix into a pipe. .

The traveling-wave tube is used as a high-output, wide-band, and high-efficiency amplifier in a microwave band to a millimeter wave band.

[Conventional technology]

The traveling wave tube has a structure in which a spiral is inserted into an elongated vacuum pipe, an electron gun and a collector are arranged at both ends, and an electron beam is sent inside the spiral.

FIG. 3 is a diagram showing a schematic configuration of a spiral of a traveling wave tube and an electron beam.

In the figure, the amplification operation in a traveling wave tube is a spiral.
The apparent velocity (phase velocity: the axial velocity of the traveling wave) at which the RF band signal (electromagnetic wave) propagating through
By making the speed of the electron beam 42 emitted from the electron gun substantially equal to that of the electron beam 42, energy is transferred from the electron beam 42 to a signal propagating in the spiral 41 by the interaction, and amplification is performed.

As described above, in the traveling wave tube, the signal is amplified by the interaction between the signal (electromagnetic wave) propagating in the helix and the electron beam. In order to perform the amplification efficiently, the helix and the electron beam are used. Must be close to each other and their coupling must be tight.

On the other hand, when the spiral and the electron beam are brought close to each other, in order to prevent a part of the electron beam from colliding with the spiral, assembly with high mechanical accuracy over the entire length of the spiral is required. Further, as the signal to be amplified becomes higher in frequency, the size of the helix becomes smaller, and the output obtained by the lowering of the heat resistance of the helix decreases, so that a higher assembling accuracy is required.

FIG. 4 is a sectional view showing a configuration of a conventional spiral circuit of a traveling wave tube.

In the figure, a spiral 41 propagates a signal in a spiral shape, and an electron beam passes inside thereof in a direction perpendicular to the plane of the drawing. The helix 41 is held by three dielectric support rods 43, and is further fixed in the pipe 45 by the elasticity of the pipe 45 serving as an envelope. The inside of the pipe 45 is vacuum.

The spiral circuit composed of the spiral 41, the support rod 43 and the pipe 45 has a length of about 150 mm to 250 mm depending on the operating frequency and design parameters of the traveling wave tube. , And the section is deformed into a triangular shape to insert the spiral 41 and the support rod 43 therein.

By the way, if you try to get high output at high frequency,
The high-frequency current flowing through the spiral 41 increases, and the spiral temperature increases. Since this rise in temperature has a great effect on the reliability of the traveling wave tube, the spiral 41 is conventionally plated with gold to reduce the resistance of the spiral surface that causes the rise in temperature.

However, it is difficult to sufficiently lower the temperature of the helix 41 only by this, and it is necessary to efficiently dissipate the heat generated in the helix 41. As one of the measures,
Increase the tightening strength of pipe 45, spiral 41, support rod 43
And the contact thermal resistance between each of the pipes 45 and
Improving heat dissipation has been done.

[Problems to be solved by the invention]

In order to increase the tightening strength of the pipe 45 by the conventional method, the thickness of the pipe 45 is increased, the sum of the outer diameter formed by the spiral 41 and the three support rods 43 is made larger than the inner diameter of the pipe 45, and Measures have been taken to reduce the amount of deformation of the pipe 45 when assembling the spiral circuit.

However, when assembling a helical circuit, the helical member 41 and the support rod 43 had to be pushed with a considerable force when the helical circuit was inserted into the pipe 45. Therefore, the support rod 43 is damaged or bent during the insertion, and the positions of the three support rods 43 become uneven in the pipe 45 (they are not disposed at equal intervals separated by 120 degrees). It was easy to occur.

As described above, not only the manufacturing yield is low in the conventional method of assembling a spiral circuit, but also the above-described inconvenience may cause variations in characteristics as a traveling-wave tube or oscillation.

On the other hand, the support rod 43 can be prevented from being broken by making it thicker, but the difference between the outer diameter of the spiral 41 and the inner diameter of the pipe 45 increases, and the difference is caused by the interaction between the signal propagating in the spiral 41 and the electron beam. Unwanted waves propagate through the spiral circuit. Such unnecessary waves may reduce the gain of a regular signal or cause deterioration of frequency characteristics. Further, by making the support rod 43 thicker, the thermal resistance from the spiral 41 to the pipe 45 increases, which is a new factor of deteriorating the output characteristics.

SUMMARY OF THE INVENTION The present invention provides a method for assembling a spiral circuit that increases the strength of pipe tightening in order to reduce the contact thermal resistance between the helix, the support rod and the pipe. It is an object of the present invention to provide a jig for assembling a spiral circuit of a traveling wave tube and a method of assembling a spiral circuit which can prevent the traveling wave tube.

[Means for solving the problem]

A jig for assembling a spiral circuit of a traveling wave tube according to claim 1 is a spiral for assembling a signal to be amplified, a plurality of support rods for holding the helix, and a plurality of supporting rods, which are integrally inserted to form a vacuum for the traveling wave tube. In a helical circuit of a traveling wave tube having a pipe constituting a part of an envelope, the outer peripheral surface is in non-contact with the inner surface of the pipe, and a plurality of support rods are brought into contact with the helix and the center axis of the helix is centered. Having a plurality of members for holding a plurality of support rods so as to be arranged at equal intervals on the circumference of the pipe, holding at least both ends of the plurality of members in a spiral and fixing the plurality of support rods to the pipe. In this structure, at least one end of the plurality of members is opened after the insertion, and the plurality of members are extracted from the pipe. According to a second aspect of the present invention, there is provided a spiral circuit assembling method, wherein a spiral, a plurality of support rods, and the spiral circuit assembling jig according to the first aspect are provided on a pipe constituting a part of a vacuum envelope of a traveling wave tube. After the insertion, the jig for assembling the spiral circuit is extracted from the pipe.

[Action]

The jig for assembling a spiral circuit of a traveling wave tube according to claim 1, wherein the spiral and the plurality of support rods are arranged in parallel with the central axis of the pipe, and are equally spaced on a circumference around the central axis of the spiral. And a plurality of members for holding the plurality of support rods against the helix at the position, and by holding both ends of the plurality of members, the helix and the support rods can be fixed. That is, since the spiral and the plurality of support rods are integrated by the jig, it is possible to avoid applying an unnecessary force to the spiral or the support rod when inserting the spiral into the pipe.

The spiral circuit assembling method according to the second aspect of the present invention provides a method for assembling a spiral circuit by inserting a spiral, a plurality of support rods, and a spiral circuit assembling jig into a pipe, and removing the spiral circuit assembly from the pipe after the insertion. Bending and rotation can be avoided, and a spiral circuit with little twist can be assembled.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of a spiral circuit using the spiral circuit assembly jig according to the first aspect.

In the figure, a spiral circuit composed of a spiral 41, a support rod 43 and a pipe 45 is the same as the conventional spiral circuit shown in FIG. The present invention is characterized in that the spiral circuit assembling jig 11 for integrally fixing the spiral 41 and the three support rods 43 when inserting the spiral 41 and the three support rods 43 into the pipe 45 is used in the assembly of the spiral circuit. .

The jig 11 for assembling a spiral circuit has a structure in which three support rods 43 are arranged at equal intervals at exactly 120 degrees apart from the spiral 41. The spiral circuit assembling jig 11, which is divided into three in the cross section shown in FIG. 1, is integrated at one end of the spiral 41 and one end of the support rod 43, and is integrated at the other end by a predetermined fastener. However, when the assembly is completed, the fastener can be removed from the spiral circuit by removing the fastener.

The jig 11 for assembling the spiral circuit includes the deformed pipe 45
The shape and dimensions are selected such that the outer periphery does not contact the inner surface of the. Furthermore, the state of contact between the spiral 41 and the support rod 43 changes due to the tightening of the pipe 45, and the spiral 41
There is a possibility that the position of the support bar 43 changes in the center direction.
Therefore, the jig 11 for spiral circuit assembly that comes into contact with the circumference of the support rod 43 has an allowance for contact with the support rod 43 by an amount corresponding to a slight movement of the support rod 43.

FIG. 2 is a view for explaining an assembling method using the spiral circuit assembling jig according to the first embodiment.

In the figure, a pipe 45 is placed on a V groove 23 having an angle of about 60 degrees provided on one crushing jig 21, and the other crushing jig 22 is placed thereon. Each crushing jig 21 sandwiching the pipe 45,
The pipe 22 is tightened by using bolts 24, and a force is applied from three directions by two sides of the V-groove 23 and the crushing jig 22, so that the cross section of the pipe 45 is crushed in a triangular shape and deformed. .

For such a pipe 45, a spiral 41 and a support rod
43 is inserted together with the jig 11 for assembling the spiral circuit to integrate it.

By the way, since the entire length of the spiral circuit is much longer than the inner diameter of the pipe 45, the jig 11 for assembling the spiral circuit includes the spiral 41 and the three support rods 43 over the entire length of the spiral circuit.
May not be fixed sufficiently. In such a case, as shown in FIG.
A fixing jig 27 for fixing the 43 and the spiral circuit assembling jig 11 is used.

The spiral 41 and the three support rods 43 integrated by the spiral circuit assembling jig 11 and the fixing jig 27 are gradually inserted into the pipe 45 which has been subjected to a predetermined deformation. The tool 27 is sequentially removed with insertion.

Also, the spiral circuit assembly jig 11 does not need to have a cross section as shown in FIG. 1 over the entire length of the spiral circuit. For example, the same effect can be achieved by providing the cross section shown in FIG. 1 partially at both ends and the center of the spiral circuit, and providing a margin between the spiral circuit and the support rod 43 in other portions.

Further, when inserting the spiral 41, the support rod 43 and the jig 11 for assembling the spiral circuit into the pipe 45, not only a force is applied in a direction to push them into the pipe 45, but also the other end of the pipe 45. A force may be applied in the direction in which the tip of the spiral circuit assembling jig 11 is pulled through the pipe 45. In addition, each of them may be used alone, or both a pushing force and a pulling force may be applied.

〔The invention's effect〕

As described above, by using the jig for assembling the spiral circuit according to the first aspect, it is possible to prevent the support rod from being damaged during the assembly, and to improve the production yield.

In addition, the position of the support rod in the pipe becomes uniform with respect to the helix, and variations in characteristics of the assembled traveling wave tube can be minimized.

Further, since the tightening strength of the pipe is easily enhanced, the contact thermal resistance between the helix, the support rod, and the pipe is easily reduced, and the output of the traveling wave tube can be increased.

In addition, since the support rod can be made thinner, it is possible to further reduce the contact thermal resistance, prevent a decrease in gain and a deterioration in frequency characteristics due to unnecessary waves, and easily realize a high output of the traveling wave tube. be able to.

On the other hand, in the spiral circuit assembling method according to the second aspect using the spiral circuit assembling jig according to the first aspect, an integrated spiral, a support rod, and a spiral circuit assembling jig are inserted into a pipe. By pulling out of the pipe after insertion, the bending or rotating force can be reduced,
A spiral circuit with little twist can be realized.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a spiral circuit using the spiral circuit assembly jig according to claim 1. FIG. 2 is a view for explaining a spiral circuit assembling method using the spiral circuit assembling jig according to claim 1. FIG. 3 is a diagram showing a schematic configuration of a spiral of a traveling wave tube and an electron beam. FIG. 4 is a sectional view showing a configuration of a conventional spiral circuit of a traveling wave tube. 11 ... spiral circuit assembly jig, 21, 22 ... crushing jig, 23 ... V
Grooves, 24 bolts, 27 fixtures, 41 spirals, 42 electron beams, 43 support rods, 45 pipes.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References Japanese Utility Model Showa 60-24047 (JP, U) Japanese Utility Model Showa 58-27851 (JP, U) (58) Fields surveyed (Int. Cl. ⁶ , DB name) H01J 23 / 26,23 / 27

Claims (2)

(57) [Claims] 1. A helix through which a signal to be amplified propagates, a plurality of support rods for holding the helix, and a pipe into which they are integrally inserted and constitute a part of a vacuum envelope of a traveling wave tube. In the spiral circuit of the traveling wave tube, the outer peripheral surface is not in contact with the inner surface of the pipe, the plurality of support rods are in contact with the spiral, and are arranged at equal intervals on a circumference around the central axis of the spiral. Having a plurality of members for holding the plurality of support rods so that the spiral and the plurality of support rods are fixed by sandwiching at least both ends of the plurality of members, and inserted into the pipe; A jig for assembling a spiral circuit of a traveling wave tube, wherein at least one end of the plurality of members is later opened to extract the plurality of members from the inside of the pipe. 2. A spiral, a plurality of support rods and a jig for assembling a spiral circuit according to claim 1 are integrally inserted into a pipe constituting a part of a vacuum envelope of a traveling wave tube. A method for assembling a spiral circuit, comprising extracting a jig for assembling a spiral circuit from a pipe.