JPS6335057B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a magnetron anode. Generally, microwave oven magnetrons use thick copper (Cu) as the anode cylinder.
This is generally formed by cutting a long cylindrical material to a required length, and processing the inner and outer surfaces and both opening ends into a predetermined shape. However, processing from such a cylindrical material is
It takes a lot of effort to manufacture the cylindrical material itself, and if the dimensional accuracy of the cylindrical material is low, it must be finished to the inner and outer diameter dimensions required for the magnetron anode cylinder, resulting in lower product prices. Currently, the price is set as high as desired. Therefore, in order to obtain an anode cylinder for a magnetron, it has already been proposed to form a flat plate-shaped material into a cylinder shape by rounding and butt-joining both ends, which is easy to manufacture. Furthermore, since it is possible to manufacture the cylinder to a desired diameter and to control the plate thickness at the same time during rounding, it is extremely effective in reducing product costs. This includes, for example, JP-A No. 48-90464, JP-A-49-11659, JP-A-49-67545, and JP-U-A-50.
-No. 157854, No. 157855, No. 157855, No. 157855, No. 157854, No. 157854, No. 157854
It is disclosed in various publications such as No. 121160 and USP No. 4163921. This invention basically uses the above-mentioned rounding technique, but it is an object of the present invention to provide a method for manufacturing a magnetron that can maintain reliability and desired characteristics as an anode cylinder, especially in mass production. With the goal. Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. First, copper (Cu) wound into a roll
The plate is cut to a predetermined length to produce a flat plate material 11 shown in FIG. 1A. This is rolled into a cylinder shape as shown in FIG. 1B using an appropriate mechanical tool. Then, the opposing end surfaces of the material end surfaces 12 that are butted against each other along the axial direction are deburred and cleaned with triclean or freon.
The abutting portions 12 of both end faces are brought into close contact with each other. Next, the anode cylinder 1 is formed by the above rounding process.
The brazing of the abutting portions 12 of both end faces of No. 3 and the brazing of the vane to the anode cylinder 13 and its inner peripheral surface are performed in one step, using the jig shown in FIGS. 2 and 3. That is, the restraining device 16 is arranged on a pedestal 15 having a vane mount 14. This suppressing device 16 suppresses the outer circumference of the axially intermediate portion of the anode cylinder 13 corresponding to the vane 17 position, and has a ring shape having an inner diameter approximately equal to the outer diameter of the anode cylinder 13 as shown in FIG. It is composed of an outer circumference holding jig 18 and a cylindrical ring support 19 that supports this outer circumference holding jig 18. The ring-shaped outer periphery holding jig 18 is made of a material with a coefficient of thermal expansion smaller than that of the copper material, for example, an HCF material (an Fe-based heat-resistant alloy according to the JIS standard, an alloy whose main component is Cr-Al-Fe),
The ring support 19 is made of SUS (stainless steel) material, and the outer periphery holding jig 18 is fixed to the inner periphery of one end of the ring support 19 by laser welding at 8 locations (the x marks in Fig. 3 (b) are welds). part). Also,
The other end (lower end) 19a of the ring support 19 is curled inward for reinforcement. Now, when brazing, the anode cylinder 13 is arranged so that its outer circumference is in contact with the ring-shaped outer circumference holding jig 18 placed on the pedestal 15, and the vane 17 is placed on the vane mounting table 14 inside the anode cylinder 13. contact with the surrounding area. At this time, the outer periphery holding jig 18 is at a position corresponding to the middle part of the anode cylinder, that is, the vane 17. Furthermore, the central columnar jig 20 is inserted so as to be in contact with the inside of the vane 17. In this state, the abutting portions 12 of both end faces of the anode cylinder 13 are brazed, and the anode cylinder 13 and the vane 17 are brazed together in one soldering process. The manufacturing method of the present invention is configured as described above and shown in the drawings, and in particular, the anode cylinder 1 is rounded by rolling the ring-shaped outer periphery holding jig 18, which has a lower coefficient of thermal expansion than copper.
3, further arranging vanes radially between the center columnar jig 20 and the inner circumference of the cylinder,
Since the soldering material is placed on the parts to be joined and the soldering of the abutting parts of both end faces and the soldering of the anode cylinder 13 and vane 17 are performed in one process, each part can be joined stably and dimensional accuracy can be achieved. It is possible to significantly improve reliability in mass production and maintain desired characteristics. In particular, the outer periphery holding jig 18 is made of HCF material and the ring support 19 is made of SUS material .
Since the coefficient of thermal expansion is smaller than that of the Cu material in No. 3, it prevents the abutting portions 12 on both ends from opening due to thermal expansion of the anode cylinder 13 , and has the effect of achieving a perfect airtight solder joint and improving roundness. . In other words, the arrangement of the parts before soldering is as shown in FIG. The vane 17 is placed inside the outer periphery holding jig 18, and a bar-shaped silver brazing material 22 is placed on each vane and cylinder to be joined. In this state, a slight gap is provided between each component to facilitate insertion of each component. Next, when the whole is heated to, for example, 860°C in a heating furnace, the anode cylinder and vane made of copper expand thermally to a greater extent as shown in Figure 5, and the outer periphery of the cylinder is a ring-shaped outer periphery with a low coefficient of thermal expansion. Since the cylinder is restrained by the holding jig, the cylinder is thermally deformed to fill the gap (G) between the abutting portions 12 while removing the molten solder material 21 as shown by the arrow. At this time, since each vane is also restrained on the inside by the central columnar jig 20, it expands outward as shown by the arrow, and the molten brazing material 22 flows in between and comes into close contact with the inner surface of the cylinder. It is soldered. The molten solder material completely solidifies at approximately 780℃ during the slow cooling process (in the case of silver solder), so the copper material shrinks without the solder joint opening. Therefore, a layer of brazing material with a thickness of about 0.02 mm or less is formed at the butt part after soldering, and each vane is brazed to this anode cylinder at equal intervals in the circumferential direction. Ru. Therefore, a magnetron having an anode with well-matched high frequency characteristics such as the resonant frequency of each resonant cavity can be obtained. Note that the ring support 19
In this case, the outer periphery holding jig 18 is the anode cylinder 13
It has a height positioning function so that it is located at the intermediate straight part corresponding to the vane position.

[Brief explanation of the drawing]

1 and 2 are a perspective view and a partially sectional front view showing a method for manufacturing a magnetron according to an embodiment of the present invention, and FIGS. 3A and 3B show an apparatus used in the method for manufacturing a magnetron according to an embodiment of the present invention. A front view and a plan view including a partial cross section, and FIGS. 4 and 5 are cross-sectional views of essential parts for explaining the effects of the present invention. DESCRIPTION OF SYMBOLS 11... Flat material, 12... Both end faces butt part, 13 ... Anode cylinder, 14... Vane mounting stand, 15... Pedestal, 17... Vane, 18... Ring-shaped outer periphery holding jig, 19... Ring support, 20... Center Column jig, 21, 22... brazing material.

Claims (1)

[Scope of Claims] 1. A brazing material 21 is sandwiched between the abutting end surfaces 12 of an anode cylinder 13, which is formed by rounding a flat copper material 11 and abutting both end surfaces 12 to form a cylinder. Anode cylinder 1 with
3 is fitted inside a ring-shaped outer periphery holding jig 18 made of a material with a coefficient of thermal expansion smaller than that of the copper material. A plurality of copper vanes 1 are arranged radially between the inner peripheral surface of the anode cylinder 13 and the columnar jig 20.
7, the vanes are placed on the vane mounting table 14, a solder material 22 is placed at the joint portion of the anode cylinder 13 and each vane 17, and the entire body is heated to form a joint between both ends of the anode cylinder. 1. A method for manufacturing a magnetron anode, characterized in that soldering the above and brazing the anode cylinder and vane are performed in one soldering process.