JP2002197984A - Method of producing magnetron - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of producing a magnetron, which can simply improve the performance of airtight welding. SOLUTION: The method of producing the magnetron which consists of an anode vacuum container having an anode cylinder, a plurality of veins radially arranged in the anode cylinder, a magnetic pole arranged at the opening end of the anode cylinder and a metal container arranged to cover the upper face of the magnetic pole, a cathode arranged on the center axis of the vacuum container and an antenna for emitting microwaves to the outside, comprises sequentially superimposing the magnetic pole and the metal container on a stepped portion formed inside a thin end protruded from the opening end of the anode cylinder and applying airtight welding to the thin end, in the case of which, when the thin end of the anode cylinder is bent to put the front end of the thin end in contact with the metal container, the cross section in the peripheral direction of a root portion at the thin end of the anode cylinder is made smaller than the cross section in the peripheral direction of the front end in contact therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a magnetron. More particularly, the present invention relates to a method for manufacturing a magnetron used for a microwave heating device such as a microwave oven or a radar.

[0002]

2. Description of the Related Art In a magnetron, for example, as shown in FIG. 8, a plurality of vanes 152 are radially arranged in a cylindrical anode cylinder 151, and the anode cylinder 151 is formed.
An anode vacuum vessel 155 having a pole piece 153 and a metal vessel 154 respectively disposed at the open ends of the top hat 1, and a top hat 1 disposed on the central axis of the vacuum vessel 155.
56a, end hat 156b and filament 15
6c and an antenna 158 for taking out, for example, a 2450 MHz microwave generated in the cavity to the outside. In such a magnetron, thermions emitted from the filament 156c circulate in the working space of a cavity formed between the vane 152 and the filament 156c, and oscillate microwaves. This microwave is a single vane 1
52, and is transmitted to an antenna 158 connected to the vane 152, and then emitted to an external space.

The anode cylinder 151 and the metal container 154 are
The thin end portion 159 of the anode cylinder 151 is joined by airtight welding. For example, as shown in FIG. 9A, the thin end portion 159 of the anode cylinder 151 has a substantially uniform thickness from the tip portion 159a to the root portion 159b before airtight welding, and the pole piece 153 and metal Container 154
8 and 9 (b) to 9 (c), the thin end 159 is bent, and the tip 1 is firstly bent as shown in FIGS. 8 and 9 (b) to 9 (c).
59a is brought into contact with the metal container 154,
1 is melted by welding to form a metal container 1
54 and is hermetically bonded to the outer peripheral bent portion 154a.

[0004]

However, FIG.
As shown in (a) and (b), the thin end portion 159 has a uniform thickness from the root portion 159b to the tip portion 159a, and therefore, the tip portion 159a and the root portion 159.
Have the same sectional area in the circumferential direction. Therefore, there is a problem that heat at the time of welding easily escapes from the thin end portion 159 to the main body side of the anode cylinder 151, so that the heat efficiency at the time of welding is reduced and stable airtight welding cannot be performed.

[0005] In view of the circumstances described above, an object of the present invention is to provide a method of manufacturing a magnetron that can easily improve the performance of hermetic welding.

[0006]

According to the method of manufacturing a magnetron of the present invention, an anode cylinder, a plurality of vanes radially arranged in the anode cylinder, and an open end of the anode cylinder are arranged. A pole piece, an anode vacuum container having a metal container disposed over the top surface of the pole piece, a cathode portion disposed on the central axis of the vacuum container, and an antenna for emitting microwaves to the outside A method of manufacturing a magnetron comprising: the magnetic pole piece and the metal container are sequentially superimposed on a step formed inside a thin end protruding from an opening end of the anode cylinder, and the thin end is When airtight welding is performed, when the thin end of the anode cylinder is bent and the tip of the thin end is brought into contact with the metal container, the anode cross section is determined from the circumferential cross-sectional area of the contacting end. Of the root at the thin end of the cylinder Characterized in that the cross-sectional area of the direction is small.

[0007] The method of manufacturing a magnetron according to the present invention comprises an anode cylinder, a plurality of vanes radially arranged in the anode cylinder, a pole piece arranged at an open end of the anode cylinder, and A method for manufacturing a magnetron, comprising: an anode vacuum container having a metal container disposed over an upper surface of a pole piece; a cathode portion disposed on a central axis of the vacuum container; and an antenna for emitting microwaves to the outside. Wherein the magnetic pole piece and the metal container are sequentially superimposed on a step formed inside a thin end protruding from an opening end of the anode cylinder, and airtight welding is performed on the thin end. Prior to bending the thin end of the anode cylinder, the thickness from the root to the tip of the thin end is substantially uniform,
Simultaneously with bending the thin end portion, when the tip end portion is bent and the tip end portion is brought into contact with the metal container, the thin end portion of the anode cylinder body is obtained from the circumferential cross-sectional area of the contacting end portion. Is characterized in that the cross-sectional area of the root portion in the circumferential direction is reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a magnetron according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a sectional view of an essential part showing an embodiment of a magnetron according to the present invention, FIG. 2 is a sectional view of an essential part explaining an embodiment of a manufacturing method of the present invention, and FIG. 3 is a manufacturing method of the present invention. FIG. 4 is a main part cross-sectional view for explaining another embodiment of the present invention, FIG. 4 is a main part cross-sectional view for explaining still another embodiment of the manufacturing method of the present invention,
FIG. 5 is a cross-sectional view of a main part illustrating still another embodiment of the manufacturing method of the present invention, FIG. 6 is a cross-sectional view of a main part explaining still another embodiment of the manufacturing method of the present invention, and FIG. It is principal part sectional drawing explaining further another embodiment of the manufacturing method.

As shown in FIG. 1, a magnetron according to an embodiment of the present invention includes an anode vacuum vessel 1, a cathode section 2 disposed on the center axis of the vessel 1, and a microwave generated in a cavity. The antenna 3 and the antenna ceramic 4 for taking out to the outside, and the cathode supports 5a and 5b are provided.

The anode vacuum vessel 1 has a cylindrical anode cylinder 6, a plurality of vanes 7 radially arranged in the anode cylinder 6, and an upper and lower opening end of the anode cylinder 6. Pole pieces 8 and 9 and metal containers 10 and 11 disposed over the top surfaces of the pole pieces 8 and 9.

The cathode section 2 includes an end hat 12 fixed to the tip of the cathode support 5a,
The top hat 13 is fixed to the tip of the cathode support 5b penetrating the center of the second support 2, and the filament 14 is wound around and supported by the cathode support 5b between the end hat 12 and the top hat 13.

The metal containers 10 and 11 and the anode cylinder 6
The thin end portions 6a protruding from the upper and lower open end portions of the anode cylindrical body 6 are hermetically welded to the outer bent portions 10a, 11a of the metal containers 10, 11 so that the open end portions of the anode cylinders 6 are air-tightly joined. I have.

Next, the thin end portion 6a is bent into the outer bent portion 10a.
The procedure for hermetically welding to a and 11a will be described. In order to simplify the explanation, the hermetic welding between the thin end portion 6a projecting from the upper opening end of the anode cylinder 6 and the outer bent portion 10a will be described. First, as shown in FIG. 2 (a), an anode cylinder 6 formed such that an annular thin end 6a protrudes from the cylindrical element at the upper and lower opening ends. This thin end 6a
Has a shape in which a tapered surface from the base A of the thin end portion 6a toward the metal container 10 is formed on the inner wall surface 15. Next, the pole piece 8 and the metal container 10 whose outer peripheral portion is bent are sequentially superimposed on the step 16 formed inside the thin end portion 6a. Then Figure 2
As shown in (b), the thin end portion 6a of the anode cylinder 6 is bent by, for example, a rotary pressurizing member to form the thin end portion 6a.
The tapered surface of the inner wall surface 15 of FIG. Next, the thin end portion 6a and the outer bent portion 10a are hermetically welded. As the hermetic welding, for example, electron beam welding or the like can be used.

In the present embodiment, the shape of the thin end 6a is formed by the tapered surface of the inner wall surface 15 due to the tapered surface.
When the front end B is brought into contact with the metal container 10 by bending the inner wall 15, the peripheral cross-sectional area of the tapered surface front end B of the inner wall surface 15 in contact with the metal container 10 causes the periphery of the root A of the thin end 6 a to be smaller. The cross-sectional area in the direction is reduced. For this reason, it becomes difficult for heat at the time of welding to escape to the main body side of the anode cylinder 6, and stable airtight welding can be performed without lowering the thermal efficiency. Therefore, airtightness between the anode cylinder 6 and the metal container 10 can be ensured.

In the present invention, the shape of the thin end portion 6a is not limited to the shape in which the tapered surface of the inner wall surface 15 is formed. The area can be appropriately set so that the cross-sectional area in the circumferential direction of the root portion A at the thin end portion 6a is smaller than the area.

Next, another embodiment will be described. In the present embodiment, as shown in FIG. 3A, the thin end portion 21 before bending has an inner wall surface 22 having a straight shape and an outer wall surface 23 having a chevron shape. This allows
The pole piece 8 and the metal container 10 are sequentially superimposed on the step 16 formed inside the thin end portion 21, and then the thin end portion 21 is attached to the metal container 10 as shown in FIG. After bending, the inner wall surface 22 is tapered, and the circumferential cross-sectional area of the root portion A at the thin end portion 21 is calculated from the circumferential cross-sectional area of the tapered tip portion B of the inner wall surface 22 that comes into contact. Can be reduced.

Next, still another embodiment will be described.
In the present embodiment, as shown in FIG. 4A, the thin end portion 24 before bending has an inner wall surface 25 in a mountain shape. As a result, the pole piece 8 and the metal container 10 are sequentially superimposed on the step 16 formed inside the thin end portion 24, and then, as shown in FIG. After being bent into the container 10, the angled tip of the inner wall surface 25 comes into contact with the metal container 10 and, based on the circumferential cross-sectional area of the angled tip B, the circumferential cross-sectional area of the root A at the thin end 24. Can be reduced.

Next, still another embodiment will be described. In the present embodiment, as shown in FIG.
In the thin end portion 26 before being bent, the inner wall surface 27 has a straight shape, and the outer wall surface 28 has a tapered surface extending from the root A to the outside of the metal container 10.
Thereby, the stepped portion 1 formed inside the thin end portion 26 is formed.
6, the pole piece 8 and the metal container 10 are sequentially superimposed, and then the thin end 26 is bent into the metal container 10 as shown in FIG. Thus, the circumferential cross-sectional area of the root portion A at the thin end 26 can be made smaller than the circumferential cross-sectional area of the chevron shape of the inner wall surface 27.

Next, still another embodiment will be described. In the present embodiment, as shown in FIG.
The thin-walled end 29 before bending is formed on the inner wall surface 3 of the root A.
0 has an annular groove 31 formed therein. Thereby, the pole piece 8 and the metal container 10 are sequentially superimposed on the step 16 formed inside the thin end portion 29,
Next, as shown in FIG. 6B, after the thin end portion 29 is bent into the metal container 10, the circumferential section of the root portion A of the thin end portion 29 is determined from the circumferential cross-sectional area of the inner wall surface 30. The area can be reduced.

Next, still another embodiment will be described. In the present embodiment, as shown in FIG.
In the thin end portion 32 before being bent, the inner wall surface 33 and the outer wall surface 34 have a straight shape, and the thickness from the root A to the tip B is substantially uniform. As a result, the pole piece 8 and the metal container 10 are sequentially superimposed on the step 16 formed inside the thin end 32, and then, as shown in FIG.
At the same time when the metal container 1 is bent, the bent portion 35 of the tip B is bent on the inner wall surface 33.
Touch 0. That is, by bending the distal end portion B in two steps, the circumferential cross-sectional area of the root portion A at the thin end portion 32 is made smaller than the circumferential cross-sectional area of the contacting bent portion 35.

[0022]

As described above, according to the present invention,
The performance of airtight welding in assembling the main body of the magnetron can be improved, and the airtightness between the anode cylinder and the metal container can be ensured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of a magnetron according to the present invention.

FIGS. 2A and 2B are cross-sectional views of a main part illustrating an embodiment of a manufacturing method of the present invention. FIG. 2A is a cross-sectional view of a main part before bending, and FIG. FIG.

FIG. 3 is a cross-sectional view of a main part illustrating another embodiment of the manufacturing method of the present invention. FIG. 3A is a cross-sectional view of the main part before bending.
FIG. 3B is a cross-sectional view of a main part showing a state after bending.

FIGS. 4A and 4B are cross-sectional views of main parts illustrating still another embodiment of the manufacturing method of the present invention. FIG. 4A is a cross-sectional view of main parts before bending, and FIG. It is a fragmentary sectional view.

FIG. 5 is a cross-sectional view of a main part illustrating another embodiment of the manufacturing method of the present invention. FIG. 5 (a) is a cross-sectional view of a main part before bending.
FIG. 5 (b) is a cross-sectional view of a main part after bending.

FIG. 6 is a cross-sectional view of a main part illustrating another embodiment of the manufacturing method of the present invention. FIG. 6A is a cross-sectional view of the main part before bending.
FIG. 6B is a cross-sectional view of a main part showing a state after bending.

FIG. 7 is a cross-sectional view of a main part illustrating another embodiment of the manufacturing method of the present invention. FIG. 7A is a cross-sectional view of a main part before bending.
FIG. 7 (b) is a cross-sectional view of a main part after bending.

FIG. 8 is a sectional view of a main part showing an example of a conventional magnetron.

9A and 9B are diagrams illustrating a conventional manufacturing method. FIG. 9A is a cross-sectional view before airtight welding, FIG. 9B is a cross-sectional view after bending, and FIG. 9C is after airtight welding. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Anode vacuum container 2 Cathode part 3 Antenna 4 Antenna ceramic 5a, 5b Cathode support 6 Anode cylinder 6a Thin end part 7 Vane 8, 9 Magnetic pole piece 10, 11 Metal container 10a, 11a Outer bent part 12 End hat 13 Top hat 14 Filament 15 Inner Wall 16 Step A Root B Tip

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Setsuo Hasegawa 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Satoshi Nakai 2-5-2 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Noriyuki Okada 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. 5C029 GG02

Claims (7)

[Claims] 1. An anode cylinder, a plurality of vanes radially arranged in the anode cylinder, a pole piece arranged at an open end of the anode cylinder, and a top surface of the pole piece. A method for manufacturing a magnetron comprising: an anode vacuum container having a metal container disposed therein; a cathode portion disposed on a central axis of the vacuum container; and an antenna for emitting microwaves to the outside; The pole piece and the metal container are sequentially superimposed on a step formed inside a thin end protruding from the open end of the body, and when airtight welding is performed on the thin end, the thickness of the anode cylinder is reduced. When the end portion is bent and the tip portion of the thin end portion is brought into contact with the metal container, the circumferential direction of the root portion at the thin end portion of the anode cylinder is determined from the circumferential cross-sectional area of the contacting end portion. Characterized in that the cross-sectional area of Manufacturing method of magnetron. 2. The thin end portion before being bent is formed in a shape in which a tapered surface from a root portion of the thin end portion toward the metal container is formed on an inner wall surface of the thin end portion. Manufacturing method of magnetron. 3. The method for manufacturing a magnetron according to claim 1, wherein the thin end portion before bending is formed such that an outer wall surface of the thin end portion is formed into a mountain shape. 4. The method for manufacturing a magnetron according to claim 1, wherein the thin end portion before bending is formed such that an inner wall surface of the thin end portion is formed into a mountain shape. 5. The thin end portion before bending is formed in a shape in which a tapered surface is formed on an outer wall surface of the thin end portion from a root portion of the thin end toward the outside of the metal container. 2. The method for producing the magnetron according to 1. 6. The method of manufacturing a magnetron according to claim 1, wherein the thin end before bending is formed in a shape in which an annular groove is formed in an inner wall surface of a root portion of the thin end. 7. An anode cylinder, a plurality of vanes radially arranged in the anode cylinder, a pole piece disposed at an open end of the anode cylinder, and an upper surface of the pole piece. A method for manufacturing a magnetron, comprising: an anode vacuum container having a metal container disposed therein; a cathode portion disposed on a central axis of the vacuum container; and an antenna for emitting microwaves to the outside; The pole piece and the metal container are sequentially superimposed on a step formed inside a thin end protruding from the open end of the body, and when airtight welding is performed on the thin end, the thickness of the anode cylinder is reduced. Before bending the end portion, the thickness from the root portion to the tip portion of the thin end portion is almost uniform, and simultaneously with bending the thin end portion, the tip portion is bent and the tip portion is bent. When it comes into contact with a metal container, From the circumferential cross-sectional area of the tip
A method for manufacturing a magnetron, wherein a cross-sectional area in a circumferential direction of a root portion at a thin end portion of the anode cylinder is reduced.