JPH0675376B2 - Magnetron manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for manufacturing a magnetron for a microwave oven.

(Prior Art) A conventionally used magnetron for a microwave oven is
It is constructed as shown in FIG. 3, and reference numeral 35 is an anode structure. Inside the anode cylinder 36 which is a part of the anode structure 35, a plurality of vanes 37 are radially arranged,
Two large and small strap rings 38 connect every other. Further, in the electron action space formed by the free end of each vane 37, a coiled cathode 21 is disposed along the axis of the anode cylinder 36, and both ends thereof are paired with an end hat 22 (one end hat 22). Is fixed to (not shown for convenience). Each end hat 22 is supported by cathode support rods 25 and 26 extending in the tube axis direction.

At one end of the anode cylinder 36, a pole piece 39 and a tubular metal container 40 forming a part of a vacuum container are airtightly joined, and a ceramic stem 41 is provided at the open end of the metal container 40.
Are airtightly joined.

The ceramic stem 41 is configured as shown in FIGS. 3 to 7, and is generally cylindrical and has a pair of through holes 42 and 43 through which external connection leads described later pass. And
On one surface, the through holes 42, 43 are continuous with the through holes 42, 43.
Elongated external connection lead fitting grooves 52, 53 having the same width as 43 and extending in opposite directions are formed.

Further, as is clear from FIG. 7, the ceramic stem 41
A ring-shaped recess 46 is formed on the side facing the vacuum region, and the inner surface of the ring-shaped recess 46 has two left and right substantially semicircular metal plates for joining relay metal plates (described later). A joining surface 47 is formed, a central groove 48 is formed between them for obtaining insulation between filaments, and an outer peripheral surface is formed as a metal container joining surface 49 for joining the metal container 40. Both the joint surfaces 47 and 49 are formed so as to be located on the same plane perpendicular to the central axis. Further, a hole for fitting a cathode support rod, which is diagonally aligned with the through holes 42 and 43 and has a predetermined depth.
50 and 51 are worn.

The ring-shaped recess 46 is deeper than the central groove 48 of the ceramic stem 41.

Further, as is apparent from FIG. 6, the relay metal plates 54 and 55 are respectively joined to the metal plate joint surface 47, and the relay metal plates 54 and 55 are
Cathode support rods 25 and 26 are fixed to the cathode support rod mixing holes 50 and 51 through 55. Then, the external connection leads 44, 45 pass through the through holes 42, 43 of the ceramic stem 41 and are fixed to the relay metal plates 54, 55 by penetrating.

Now, at the time of manufacturing, a molybdenum (Mo) -manganese (Mn) paste is applied to the entire surfaces of the metal plate bonding surface 47 and the metal container bonding surface 49 located on the same surface of the ceramic stem 41. After the paste is dried, it is placed in an inert gas heating furnace at about 1400 ° C. and sintered to form a so-called metallized layer.

Next, the relay metal plates 54, 55 and the metal container 40 are hermetically brazed to the corresponding joint surfaces 47, 49 with silver solder. As materials for these relay metal plates 54, 55, Kovar (trade name)
A metal having a coefficient of thermal expansion similar to that of the ceramic stem 41 such as Fe-Ni-Cr alloy and easily brazed through the metallized layer is used.

Each of the relay metal plates 54, 55 has a pair of external connection leads 44, 45 made of a metal rod such as copper or iron penetrating through the through holes formed therein, and at the through hole portions. It is airtightly joined by brazing. These external connection leads 44,
45 respectively penetrates through holes 42 and 43 of the ceramic stem 41, and as is clear from FIG.
Bent portions 44a and 45a are formed at positions corresponding to the vicinity of the ends of the. These bent portions 44a, 45a are fitted in the external connection lead fitting recessed grooves 52, 53, so that they do not rotate in the circumferential direction.

The cathode support rods 25 and 26 are the same as the relay metal plates 54 and 55, respectively.
Is fitted into and brazed to the adjacent through hole formed in, and the lower end extending further downward is fitted into each cathode support rod fitting hole 50, 51 of a predetermined depth formed in the ceramic stem 41. And is mechanically stably locked and positioned.

In this way, the cathode support rods 25 and 26 and the external connection leads 44 and 45 are electrically connected to each other via the relay metal plates 54 and 55, respectively.

(Problems to be Solved by the Invention) However, in the conventional manufacturing method as described above, the relay metal plate is used.
54, 55, and the metal container 40 and the corresponding joining surfaces 47, 49 respectively, it is necessary to put an independent silver brazing,
It has the drawback of poor workability.

On the other hand, a technique for increasing the assembling efficiency by integrating ring-shaped brazing filler metals having different diameters is disclosed in, for example, Japanese Patent Publication No. 62-36794. However, according to the technique of the publication, the brazing portion is electrically short-circuited by the spacer connecting the plurality of ring-shaped brazing materials, and an extra brazing material is used, which is not preferable.

The present invention solves the above inconveniences, and by using an integral brazing filler metal, the workability of the brazing of the ceramic stem portion is remarkably improved, and the minimum necessary brazing filler metal is used to improve the reliability. It is an object to provide a method of manufacturing a magnetron having a good brazing part.

[Structure of the Invention] (Means for Solving the Problem) The present invention is directed to an outer peripheral ring portion having a diameter corresponding to the diameter of the open end of a metal container, and a ring-shaped recess of a ceramic stem integrated with the outer peripheral ring portion. And a pair of island-shaped portions having two pairs of through-holes that are connected to the coupling portions and also serve as positioning and that sandwich a slit that corresponds to the central groove of the ceramic stem. Is a method for manufacturing a magnetron in which the brazing filler metal having the above is used, the brazing filler metal is arranged between the lamic stem and the relay metal plate and the metal container, and these, the cathode support rod and the external connection lead are simultaneously brazed.

(Operation) According to the present invention, since the integrated brazing filler metal is used as the brazing filler metal, there is no fear of causing an electrical short circuit of each part efficiently with the minimum required amount of brazing filler metal, and workability is improved. Remarkably improved.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

Since the magnetron obtained by the manufacturing method of the present invention is also as described above, each drawing used in the above description will be reused.

In the manufacturing method according to the present invention, when brazing each component, an integral brazing material is used unlike the conventional one. First, the integral brazing material will be described.

That is, the integral brazing material 60 used in the present invention is constructed as shown in FIG. 2, and is made of silver brazing material, and reference numeral 61 is an outer peripheral ring portion. Inside the outer peripheral ring portion 61, a pair of connecting portions 62, 63 are formed integrally with the outer peripheral ring portion 61 in the radial direction, and a pair of island-shaped portions 64 integrally connected to the pair of connecting portions 62, 63. ,
64 is provided so as to sandwich the slit 66. Then, in the island-shaped portions 64 and 65, two pairs of through holes 67-
70 is drilled.

Incidentally, reference numeral 71 is a space portion, which is a portion where the plate-shaped brazing material 2 is removed by press punching together with the slit 66 and the through holes 67 to 70.

In this case, the outer peripheral ring portion 61 substantially corresponds to the metal container joint surface 49, the connecting portions 62 and 63 are located above the ring-shaped recess 46 formed in the ceramic stem 41, and the island-shaped portion 64,
Of course, 65 substantially corresponds to the metal plate joint surface 47 and the relay metal plates 54 and 55. In addition, the two pairs of through holes 67 to 70 formed in the island-shaped portions 64 and 65 are the through holes 4 formed in the ceramic stem 41.
2, 43 and the cathode support rod fitting holes 50, 51, and the function of positioning the cathode support rods 25, 26 and the external connection leads 44, 45, and thereby positioning the outer peripheral ring portion 61 of the integral brazing material 60. have. Further, the slit 66 is aligned with the central groove 48 formed in the ceramic stem 41.

In order to manufacture a magnetron using such an integrated brazing material 60 , first, a metal plate joining surface located on the same surface of the ceramic stem 41 (also corresponding to FIG. 7) shown in FIG.
Molybdenum (Mo)-
Apply manganese (Mn) paste. After the paste is dried, it is placed in an inert gas heating furnace at about 1400 ° C. and sintered to form a so-called metallized layer.

Next, the integral brazing material 60 is arranged on the metallized layer. Then, the relay metal plates 54, 55 are placed on the island-shaped portions 64, 65 of the integrated brazing material 60 , and the metal container 40 is placed on the outer peripheral ring portion 61.

Further, connect the external connection leads 44 and 45 to the ceramic stem, respectively.
Through-holes 6 formed in the through-holes 42 and 43 of 41 and the island-shaped portions 64 and 65.
The through holes of 7, 68 and the relay metal plates 54, 55 are penetrated.

Further, the cathode support rods 25 and 26 are fitted into the through holes 69 and 70 formed in the island-shaped portions 64 and 65, the through holes of the relay metal plates 54 and 55, and the cathode support rod fitting holes 50 and 51, respectively. To combine.

In this way, with the ceramic stem 41 on the lower side, the metal container 40
Is held upward by a holding jig (not shown), and each part is simultaneously airtightly brazed through the hydrogen furnace.

[Effects of the Invention] As described above, according to the present invention, the connecting portion on the ring-shaped recess of the ceramic stem of the brazing material does not flow into the ring-shaped recess, and the metal container and the relay metal plate are connected to each other. Since the current is shunted, it is useful for brazing, and there is no risk of electrical short circuit of each part.

Further, the brazing filler metal is used as the brazing filler metal, and the through holes of the island-shaped portion also serve as the positioning of the leads, so that the workability is remarkably improved.

Since the central groove 48 is relatively shallow, the central groove 48
The presence of the braze material above may melt and cause the central groove 48 to electrically create a short circuit, but this is not a risk in the present invention. On the other hand, since the ring-shaped recess on the outer periphery is relatively deep, even if the connecting portion of the brazing material is melted, it is absorbed by the outer ring portion or the island-shaped portion and does not drip or flow into the ring-shaped recess.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an embodiment of the present invention, FIG. 2 is a plan view showing an integrated brazing material used therein, and FIG. 3 is a longitudinal sectional view showing a magnetron obtained by the manufacturing method of the present invention. FIG. 4 is a top view of the main part, and FIGS. 5 to 7 are perspective views of the main part. 21 …… Cathode, 25, 26 …… Cathode support rod, 35 …… Anode structure, 40 …… Metal container, 41 …… Ceramic stem, 42,43 …… Through hole, 44,45 …… External connection lead, 46
…… Ring-shaped recess, 48 …… Central groove, 54, 55 …… Relay metal plate, 60 …… Integral brazing material, 61 …… Perimeter ring part, 62, 63…
… Connecting parts, 64, 65 …… Island parts, 66 …… Slits, 67-70
…… Through hole.

Claims (1)

[Claims] 1. A cylindrical metal container which is airtightly joined to a part of an anode structure to form a part of a vacuum container, a cathode arranged on a central axis part of the anode structure, and a cathode which supports the cathode at its tip. A cathode support rod and an opening end of the metal container supporting the cathode support rod are airtightly brazed to each other and have a ring-shaped recess and a central groove connected to the ring-shaped recess on the side surface of the metal container and penetrate in the axial direction. A ceramic stem having a hole, a relay metal plate brazed to a cathode-side surface of the ceramic stem, and an external connection lead inserted into a through hole of the ceramic stem and brazed to the relay metal plate. In the method of manufacturing a magnetron, an outer peripheral ring portion having a diameter corresponding to a diameter of an opening end portion of the metal container, and the outer peripheral ring portion integrated with the outer peripheral ring portion. A pair of island-shaped portions having a pair of connecting portions having substantially the same length as the width of the recess and two pairs of through holes integrally connected to the connecting portions and also serving as positioning, and sandwiching a slit corresponding to the central groove. A method for manufacturing a magnetron, wherein an integrated brazing material having a metal oxide is placed between the ceramic stem, the relay metal plate, and the metal container, and these, the cathode support rod, and the external connection lead are simultaneously brazed.