JP3069069B2 - Cathode support structure for magnetron for microwave oven and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to the Ru <br/> relates to a cathode support structure and the manufacturing how the magnetron for microwave oven.

[0002]

2. Description of the Related Art A conventional cathode support structure of a magnetron for a microwave oven will be described with reference to FIG. Code 5
Reference numeral 1 denotes a metal container, and a metal container 51 constitutes a part of a vacuum container forming a magnetron for a microwave oven.
a and a flange portion 51b. Metal container 51
The ceramic stem 52 is hermetically joined to the lower end opening of the ceramic stem 52.

The cathode side surface of the ceramic stem 52,
That is, the groove 52a and the concave portion 52b are provided on the surface on the vacuum side. Then, as shown in the enlarged view (b) of the inside of the circle C, a conductive surface 53 is formed by metallization on a portion excluding the groove 52a and the concave portion 52b. Are joined. Cathode support rods 55a and 55b for supplying power to the cathode are connected to the connection metal plate 54 on the ceramic stem 52, and lower end portions of the cathode support rods 55a and 55b extend into the recesses 52b of the ceramic stem 52. ing. The ceramic stem 52 has external connection leads 5
6 penetrates and the upper end of the external connection lead 56 is connected to the connection metal plate 5.
4 is electrically connected. External connection lead 56 is 2
Although a book is provided, only one is shown in relation to the drawing.

Accordingly, the cathode support rods 55a, 55
b and the external connection lead 56 are electrically connected via the connection metal plate 54, and electric power supplied from outside is supplied to the external connection lead 56, the connection metal plate 54, and the cathode support rods 55 a and 55
b to be sent to the cathode. The upper ends of the two cathode support rods 55a and 55b are eventually connected to end hats respectively. In this state, the end hat 5 is connected to only one of the cathode support rods 55b.
7 is connected.

Here, a method of manufacturing the cathode support structure having the above structure will be described with reference to FIG. 6, parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and redundant description is partially omitted. Reference numeral 61 denotes a first jig. The first jig 61 is provided with a large-diameter concave portion 61a and a small-diameter concave portion 61b. The cylindrical portion 51a and the ceramic stem 52 of the metal container 51 are accommodated and held in the large-diameter concave portion 61a. In the small-diameter concave portion 61b,
The external connection lead 56 is stored and held.

Reference numeral 62 denotes a second jig, which is formed as a pair so as to sandwich the two cathode support rods 55a and 55b from both sides, and has a connection metal plate 54 and a brazing material (not shown) between the two and the ceramic stem 52. ) And at the same time, the cathode support rod 5
5b and the connecting metal plate 54
Between or end hat 57 and ceramic stem 5
The distance between the two is regulated.

Reference numeral 63 denotes a third jig, which utilizes an end hole 57 and a cathode support rod 55 using a through hole provided in the center.
a is held.

[0008]

In the above-described conventional cathode support structure, a connection metal plate 54 is used to connect the cathode support rods 55a and 55b to the external connection leads 56, and the connection metal plate 54 is made of ceramic. It is brazed to the conductive surface 53 on the surface of the stem 52. Further, when manufacturing the cathode support structure, a first jig 61 for housing and holding the metal container 51 and the ceramic stem 52 and a second jig for regulating the interval between the end hat 57 and the ceramic stem 52. A jig 62 and a third jig 63 for holding the cathode support bar 55a and three jigs are used.

However, the size of the magnetron for a microwave oven has been reduced, and accordingly, the components constituting the cathode support structure have also been reduced in size. For example, the connecting metal plate 54 has become smaller, and assembling work during manufacturing has become difficult. Also,
The second jig 62 causes a heating loss at the time of brazing, and reduces the efficiency of the brazing operation.

[0010] This invention is to solve the drawbacks mentioned above, aims at manufacturing to provide a cathode support structure and the manufacturing how easy magnetrons for microwave oven.

[0011]

According to the present invention, there is provided a stem through which an external connection lead electrically connected to a cathode support for supporting a cathode of a magnetron is formed, and a stem formed on a vacuum side of the stem. In a cathode support structure of a magnetron for a microwave oven having a cathode support and a conductive surface to which the external connection lead is electrically connected, the conductive surface portion is provided on at least one of the cathode support and the external connection lead. It is characterized in that a portion having a width that is larger in the lateral direction than the portion that crosses is provided on the vacuum side of the stem.

Further, according to the method for manufacturing a cathode supporting structure of a magnetron for a microwave oven according to the present invention, a cylindrical metal container part forming a part of a vacuum envelope constituting a magnetron, and a metal container side surface are provided. A step of holding the stem portion on which the conductive surface is formed by the concave portion of the first jig; and a cathode support portion and an external portion having a large-diameter portion larger than a portion crossing the conductive surface formed on the vacuum side of the stem. between the conductive surface of at least one of said large diameter portion of the connecting leads and the stem surface, and, between the conductive surface of the end portion of the metal container the stem surface, their respective braze the A step of holding the cathode support with a second jig, and a step of heating and brazing the brazing material portion.

[0013]

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method of manufacturing an embodiment of the present invention will be described with reference to FIG.

Reference numeral 11 denotes a first jig, and a concave portion 12 is formed in a central portion of the first jig 11. The recess 12 includes an upper end portion 12a having a larger diameter, an intermediate portion 12b having a slightly smaller diameter, and an elongated lower end portion 12c having a smallest diameter. The intermediate portion 12b houses and holds a ceramic stem 13 constituting a magnetron for a microwave oven. A ceramic stem 1 is provided at the lower end 12c.
External connection leads 14 penetrating the three portions are housed and held.

The surface of the ceramic stem 13 on the vacuum side, that is, the upper surface in FIG.
The conductive surface 15 is formed by metallization in a region excluding the groove 13a and the concave portion 13b. The conductive surface 15 is made of, for example, molybdenum (Mo) -manganese (M
n).

At the upper end 12a of the recess 12, a metal container 16 is provided.
Is stored and held. The metal container 16 forms a part of a vacuum container of a magnetron for a microwave oven, and has a cylindrical portion 16.
a and a flange 16b. Metal container 16
The cylindrical opening at the lower end is located on the conductive surface 15 around the ceramic stem 13, and the lower end of the metal container 16 is connected to the conductive surface 15.
A brazing material 17 is fixed between them.

Reference numerals 18a and 18b denote cathode support rods.
Its lower end extends into the recess 13 b of the ceramic stem 13. The large diameter portion D is provided on the cathode support rods 18a and 18b above the ceramic stem 13, that is, on the vacuum side. The large-diameter portion D has, for example, a tapered shape in which the diameter on the lower end side is large and the diameter is gradually reduced, and the lower end of the large-diameter portion D is a flat surface substantially perpendicular to the extension direction of the external connection lead. I have. Then, the lower end of the large diameter portion D and the conductive surface 1
5, a brazing material 17 is sandwiched and fixed. The two cathode support rods 18a and 18b extend upward in the drawing, and finally end hats are connected to each other. In this state, the end hat 19 is welded only to the upper end of the cathode support rod 18b. .

Above the first jig 11, a second jig 20 for holding each part of the cathode support rod 18a and the end hat 19 is located, and a recess 21 is formed at the center thereof. The recess 21 includes a lower end portion 21a having a larger diameter, an intermediate portion 21b having a smaller diameter than the lower end portion 21a, and an upper end portion 21c having a smallest diameter. The lower end 21a surrounds the periphery of the two cathode support rods 18a and 18b, and the intermediate part 21b holds the end hat 19 and the upper end 21c holds the cathode support rod 18a. Also, the first jig 1
A flange 16b of the vacuum vessel 16 is sandwiched and fixed between the upper surface of 1 and the lower surface of the second jig 20.

Although not shown in the drawing, the external connection leads 14 pass through the ceramic stem 13. A portion that protrudes above the ceramic stem 13 is provided with a large diameter portion similar to the cathode support rods 18a and 18b, and a brazing material is fixed between the large diameter portion and the conductive surface 15 of the ceramic stem 13.

Then, the metal container 16, the ceramic stem 13, the cathode support rod 18a, the external connection lead 14 and the like are held in the furnace while being held by the first jig 11 and the second jig 20 , and are heated and brazed. Is performed. Thereby, the metal container 16 and the cathode support rods 18a, 18
b, the external connection leads 14 are respectively joined to the conductive surface 15 of the ceramic stem 13. At this time, for example , the cathode support 18 a is electrically connected to the external connection lead 14 via the conductive surface 15.

According to the above configuration, the cathode support rod 1
A large-diameter portion D is formed on each of the external connection leads 14 and 8a and 18b, and the brazing material 17 can be fixed between the large-diameter portion D and the conductive surface 15 using the lower end surface. At this time, the lower end surface of the large-diameter portion D comes into contact with, for example, a brazing material portion, and the cathode support rod 1
Since the 8a and 18b are supported, for example, a distance between the end hat 19 connected to the cathode support rod 18b and the ceramic stem 13 is maintained at a correct distance.

Therefore, there is no need for a connecting metal plate or a jig for regulating the distance between the end hat and the ceramic stem required in the prior art. As a result, handling of small parts is eliminated. In addition, since there is no heating loss due to the jig, the manufacturing becomes easier accordingly.
Moreover, the number of parts and jigs is reduced, and an inexpensive magnetron for a microwave oven can be provided. Further, since the lower end surface of the large-diameter portion D is flat, the brazing material can be securely fixed.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 2, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and duplicate description will be partially omitted.
In the embodiment of FIG. 1, the cathode supports 18a, 18b
Also, the large diameter portion of the external connection lead 14 is tapered. In the case of FIG. 2, for example, the large-diameter portion D of the cathode support rod 18a is formed in a columnar shape having a uniform diameter. The entire portion of the cathode support bar 18b from the portion in contact with the ceramic stem 13 to the end hat 19 constitutes a cylindrical large-diameter portion D. In the configuration of FIG. 2 as well, a large-diameter portion D having a larger width in the lateral direction than a portion crossing the conductive surface 15 on the surface of the ceramic stem 13 is formed on the vacuum side of the stem 13. Therefore, the brazing material can be fixed using the large diameter portion D, and the height between the end hat 19 and the ceramic stem 13 can be maintained at a correct distance.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 3, portions corresponding to FIG. 1 and FIG. 2 are denoted by the same reference numerals, and duplicate description will be partially omitted. In this embodiment, a large-diameter portion D whose diameter gradually increases upward from a portion crossing the conductive surface 15 of the ceramic stem 13 is formed. Also in this case, a large-diameter portion D having a larger width in the lateral direction than the portion crossing the conductive surface portion is formed on the vacuum side of the stem. Therefore, the large diameter portion D
Can be used to fix the brazing material, and the height between the end hat 19 and the stem ceramic 13 can be maintained at the correct distance.

Here, the cathode support members 18a and 18b, the external connection leads 14 and the conductive surface 1 of the ceramic stem 13 are formed.
5 will be described with reference to FIG. In FIG.
1 to 3 are denoted by the same reference numerals,
A duplicate description is partially omitted. In this figure, two external connection leads 14 are shown. The upper ends 14a of the two external connection leads 14 pass through the ceramic stem 13 and have separate cathode support members 18a and 18b and the conductive surface 1 respectively.
5 are shown connected. In addition, the cathode support members 18a and 18b and the external connection leads 14 include:
A cylindrical large-diameter portion D1 or a tapered large-diameter portion D2 is formed.

As described above, according to the present invention, with respect to the cathode support rod and the external connection lead, the large-diameter portion having a width larger in the lateral direction on the vacuum side of the ceramic stem than the portion crossing the conductive surface portion of the ceramic stem. Is formed. According to this structure, the brazing material can be supported by using the large diameter portion, and at the same time, the height of the end hat and the stem ceramic can be maintained at a correct distance. For this reason, a connecting metal plate and a jig for regulating the interval between the end hat and the ceramic stem, which are required in the related art, become unnecessary, and the number of components and jigs is reduced. Therefore, an inexpensive magnetron for a microwave oven can be provided. In addition, the number of small parts is reduced, and there is no heating loss due to the jig, so that the manufacturing becomes easy.

In the above embodiment, the large diameter portions are formed on both the cathode support rod and the external connection lead. However, the effect of the present invention can be obtained by providing the cathode support rod and the external connection lead only on one side.

In the above-described embodiment, the tapered or cylindrical large-diameter portion is formed on the cathode support rod or the external connection lead. However, the large-diameter portion may have a structure in which the brazing material can be fixed and the cathode support rod and the external connection lead can be supported, so that the cathode support rod and a part of the outer surface of the external connection lead protrude laterally. You can also.

Further, since the large diameter portion is formed on the cathode support rod and the external connection lead, electrical connection can be reliably performed.

[0031]

Effects of the Invention According to the present invention, it cathode support structure and real <br/> current manufacturing how the magnetron for the microwave oven can be supplied easily and inexpensive magnetron for a microwave oven is manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view for explaining a manufacturing method according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view for explaining another embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view for explaining another embodiment of the present invention.

FIG. 4 is a perspective view illustrating a connection state between a cathode support and external connection leads and a conductive surface of a ceramic stem according to the embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view for explaining a conventional example.

FIG. 6 is a schematic cross-sectional view for explaining a manufacturing method of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... 1st jig 12 ... recess of 1st jig 13 ... ceramic stem 14 ... external connection lead 15 ... conductive surface 16 ... vacuum vessel 17 ... brazing material 18a, 18b ... cathode support 19 ... end hat 20 ... 2nd jig

Claims (3)

(57) [Claims] 1. A stem through which an external connection lead electrically connected to a cathode support for supporting a cathode of a magnetron is formed, and the cathode support and the external connection lead formed on a vacuum-side surface of the stem. A conductive surface electrically connected to the cathode support structure of a magnetron for a microwave oven, wherein at least one of the cathode support and the external connection lead is laterally larger than a portion crossing the conductive surface portion. A cathode support structure for a magnetron for a microwave oven, wherein a width portion is provided on a vacuum side of the stem. 2. A portion having a large width in a lateral direction is a columnar shape having a constant outer diameter or a tapered shape having a gradually changing outer diameter, and a lower end surface on a conductive surface side is a direction in which a cathode support rod or an external connection lead extends. The cathode support structure of a magnetron for a microwave oven according to claim 1, wherein the cathode support structure is a plane perpendicular to the cathode. 3. A cylindrical metal container part forming a part of a vacuum envelope constituting a magnetron, and a stem part having a conductive surface formed on a surface of the metal container on a surface of the metal container by a concave portion of a first jig. A step of holding, and a large-diameter portion having a larger diameter than a portion crossing the conductive surface is formed on the vacuum side of the stem, the large-diameter portion of at least one of the cathode support and the external connection lead, and the stem portion of the stem surface. between the conductive surface, and, between the conductive surface of the end portion of the metal container the stem surface, and fixing across their respective brazing material, wherein the cathode support cowpea second jig And a step of heating and brazing the brazing material portion, the method comprising the steps of: