JPS6313235A - Manufacture of magnetron - Google Patents

Abstract

PURPOSE:To lessen an amount of shift of an antenna lead, by forming a flat part beforehand on a part of antenna lead around which a metal exhaust pipe is fitted, and squashing the pipe for vacuum sealing and cutting in the lateral direction of the flat part of the antenna lead. CONSTITUTION:An antenna lead 14 is connected to a couple of strap rings 3 which connect together the plural number of vanes of an anode cylinder 1, and the antenna lead is drawn out through a side pipe 6, an insulation pipe 7 and a metal exhaust pipe 8, and the end part of the exhaust pipe 8 is squashed, vacuum sealed and cut, thus a magnetron is assembled. In this case, a part of the antenna lead 14 around which the exhaust pipe 8 is fitted is formed beforehand in a flat part 15 with its width equal to the dimension of inside diameter of the exhaust pipe 8. And the end part of the exhaust pipe 8 is pressed by a die 13 so as to squash the antenna 14 and sealing cut is applied thereto as soon as the electrical connection is completed. Therefore, shifting of the antenna lead caused by sealing and cutting the exhaust pipe can be lessened and deformation of the vanes 2 can be avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a magnetron, and more particularly to an improvement in a method for sandwiching and sealing an antenna lead in a metal exhaust pipe provided at an output section.

Conventional technology A method of manufacturing a magnetron is widely practiced in which a metal exhaust pipe is used as an output section, an antenna lead is passed through the pipe, and the exhaust pipe is sealed after evacuation.

5 and 6 show the cross-sectional structure of a magnetron manufactured using the above manufacturing method, and FIG. 6 is a cross-sectional view taken along the line A--A in FIG. 5. In the figure, 1 is the anode cylinder, 2 is the anode cylinder 1
a plurality of vanes protruding from the inner surface toward the center of the cylinder, 3
is disposed approximately at the center of the vane 2 in the tube axis direction, and
a pair of strap rings connected to every other vane 2; 4 an antenna lead connected to the strap ring 3 and extending through a coupling hole 5 provided on the inner surface of the anode cylinder 1; 6 an antenna side tube; 7 is an insulator, 8 is a metal exhaust pipe, 9
10 is a cathode, 10 is a magnetic pole provided vertically facing each other, 11 is a cap, and 12 is a Nutem side tube.

After assembling each part in the above configuration, the inside of the tube is evacuated, and as shown in FIG. 5, a predetermined position of the exhaust pipe 8 is crushed from both sides as shown by arrow F using a sealing die 13 to cut the seal. . At this time, the exhaust pipe 8 sandwiches the antenna lead 4 and is electrically connected.

Problems to be Solved by the Invention In the manufacturing method described above, as the antenna lead 4 is crushed during sealing, it moves as shown by arrow S in FIG. In particular, in a structure in which the antenna lead 4 is joined to the strap ring 3, the strength is weak and the amount of movement is large. For example, if the wire diameter of the antenna lead 4 is 2.3 mm,
If the exhaust pipe diameter is 7 mm, arrow S on antenna lead 4
The amount of movement in the direction was approximately 0.6 mm. As a result, the strap ring 3 is deformed and the oscillation frequency changes when the strap ring interval G becomes smaller than the predetermined dimension. In extreme cases, the two strap rings may come into contact with each other, making it impossible to oscillate. At the same time, the vanes 2 are also deformed, resulting in a reduction in multi-circuit efficiency due to the small spacing W between the vanes.

Means for Solving the Problems The present invention solves the above problems by reducing the amount of movement of the antenna lead toward the anode cylinder side when sealing a metal exhaust pipe, and reducing the amount of strap rings and vanes. The present invention provides a method for manufacturing a magnetron that reduces deformation.

Therefore, the present invention includes an antenna lead having one end connected to a strap ring disposed approximately in the center of a plurality of vanes in the tube axis direction, and an exhaust pipe into which a part of the antenna lead is coaxially inserted. , a flat part having a width substantially equal to the inner diameter of the exhaust pipe is formed in advance at a portion of the antenna lead into which the exhaust pipe is inserted, and the flat part is sealed in a cross-section in the lateral direction of the flat part. It is.

Effect: Since the above-described method performs sealing cutting in the lateral direction of the pre-formed flat section cross section, the crushing area Sr (described later) of the antenna lead during sealing cutting can be reduced. This crushing area Sr is related to the amount of movement of the antenna lead in the direction perpendicular to the direction of the sealing cut, and the crushing area Sr
The smaller the value, the smaller the amount of movement of the antenna lead. Therefore, the amount of deformation of the strap ring and vane during sealing can be reduced.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a sectional view of essential parts of a magnetron according to the present invention, FIG. 2 shows a sectional view taken along the line B--B in FIG. 1, and FIG. 3 shows a view taken along arrow C in FIG.

In the figure, 14 is an antenna lead connected to the strap ring a, and a coupling hole 5 provided on the inner surface of the anode cylinder 1.
, extends coaxially through the antenna side pipe 6 and the insulator 7 to the metal exhaust pipe 8, and the portion inserted into the exhaust pipe 8 has a width WA approximately equal to the inner diameter d of the exhaust pipe 8. A flat portion 15 having a shape is preformed. The other parts are the same as those of the conventional example shown in FIG.

After the entire assembly, the inside of the tube is evacuated, and the sealing die 13 is inserted in the short direction of the cross section of the flat part 15 as shown in FIGS. 2 and 3.
A predetermined position of the exhaust pipe 8 is pinched and vacuum sealed from both sides in the direction of arrow F, and the flat portion 15 provided on the antenna lead 14 is sandwiched between the exhaust pipe 8 and electrically connected. At this time, since the seal is cut in the lateral direction of the flat portion 15, the amount of movement of the antenna lead 14 in the direction perpendicular to the seal cut direction, that is, the amount of movement toward the anode cylinder 1 can be reduced. For example, when the wire diameter of the antenna lead 14 is 2.3=the thickness of the flat portion 15 in the width direction is o and 6rrIm, the amount of movement is 0.1 mm. To explain this point, FIG. 4 shows an enlarged sectional view of the main part of the sealing cut portion, and if the area crushed by the sealing die 13 (the above-mentioned crushed area) is Sr, the sealing cut υ At this time, this area (or volume) is absorbed in the direction perpendicular to the direction of the sealing cut (in the direction of arrow S). Therefore, the smaller the compressed area Sr is, the more the antenna lead 14 is moved in the direction of arrow S.
The amount of movement can be reduced. In this embodiment, since the flat part 15 is provided and the flat part 15 is sealed and cut in the transverse direction of the cross section, the crushing area can be reduced to Sr', and the amount of movement of the antenna lead 14 in the direction of the arrow S can be reduced.

Here, a method of reducing the wire diameter of the antenna lead 14 can be considered, but a predetermined cross-sectional area is required from the viewpoint of output power, and it is impossible to make it sufficiently small.

It is also conceivable to use an antenna lead with a flat cross section, but this would complicate the shape of the coupling hole 5 provided on the inner surface of the anode cylinder 1, making processing difficult.

Further, in this embodiment, since the width WA of the flat portion 15 is made approximately equal to the inner diameter d of the exhaust pipe 8, the coupling hole 5 and the antenna side pipe 6
, the antenna lead 14 can be positioned coaxially with respect to the central axes of the insulator 7 and the exhaust pipe 8. If the antenna lead 14 is not arranged coaxially, a problem arises in that the high frequency coupling characteristics between the cavity resonator and the antenna output section deteriorate.

Effects of the Invention As detailed above, the method for manufacturing a magnetron according to the present invention provides the following effects.

(1) In a magnetron that has a structure in which the antenna lead is taken out directly from a strap ring provided approximately at the center of multiple vanes, a flat part is formed in advance in the part where the exhaust pipe of the antenna lead is inserted, and the short side of the cross section of the flat part is formed in advance. By cutting the seal in this direction, the amount of movement of the antenna lead toward the anode cylinder side during seal cutting can be reduced. Therefore, strapping and deformation of the vane can be reduced, variations in oscillation frequency can be reduced, and circuit efficiency can be prevented from deteriorating. Therefore, magnetrons with stable quality can be manufactured even in mass production.

(Since the width of the 21 flat part is set approximately equal to the inside diameter of the exhaust pipe,
The coaxiality of the antenna lead with respect to the output section during assembly can be obtained with high accuracy, and deterioration of high frequency coupling characteristics between the cavity resonator and the output section can be prevented.

[Brief explanation of drawings]

FIG. 1 is a partial sectional view of a magnetron showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line B-B in FIG. 1, FIG. 5 is a partial sectional view of a conventional magnetron, and FIG. 6 is a sectional view taken along line A--A in FIG. 5. 1... Anode cylinder, 2... Vane, 3...
...Strap ring, 5...Connection hole, 8...
... Exhaust pipe, 14 ... Antenna lead, 15 ・
...Flat area. Name of agent: Patent attorney Toshio Nakao and 1 other person/-
--Intestinal food bag 2---Home 14- Antenna lead Figure 2 Figure 3 Figure 4 Figure 5 Figure 1? Figure 6 1'

Claims (1)

[Claims] a plurality of vanes protruding from the inner surface of the anode cylinder toward the center of the cylinder; a pair of strap rings arranged approximately in the center of the plurality of vanes in the axial direction of the tube and connected to every other vane; and the strap ring. an antenna lead extending through a coupling hole provided on the inner surface of the anode cylinder; and a metal exhaust pipe into which a part of the antenna lead is inserted; The antenna lead and the exhaust pipe are electrically connected and vacuum-sealed, a flat portion having a width approximately equal to the inner diameter of the exhaust pipe is formed in advance at a portion of the antenna lead to be inserted into the exhaust pipe, and the A method for manufacturing a magnetron in which sealing is cut in the short direction of the cross section of the flat section.