JPH0762980B2 - Method for manufacturing magnetron anode assembly - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing a magnetron anode assembly.

[Technical background of the invention and its problems]

The anode structure of the magnetron has a structure in which a plurality of anode vanes are radially fixed to the inner circumference of an anode cylinder, and each anode vane is electrically short-circuited every other pair by strapping. In the manufacture, generally, a plurality of anode vanes are fixed inside a copper anode cylinder, and at the same time, a pair of inner and outer strap rings are brazed while being positioned by a holding jig in a strap mounting groove of the vane. Needless to say, a holding jig is required for each anode assembly, and particularly in mass production such as a magnetron for a microwave oven, a large amount of this jig is required. The jig used in this brazing process must be made of a material that can withstand repeated use up to a high temperature of approximately 900 ° C, has little dimensional change, and has a small thermal expansion. For this reason, the jig used for such brazing is expensive and wears out significantly.

A method of brazing the anode structure without using a jig for positioning the vane or holding the strap ring has already been disclosed in Japanese Patent Publication No. 57-18664. This is a method in which the mutual joints are temporarily fixed by welding prior to brazing of the components of the anode assembly, and then brazing is performed without using a jig. Although the above inconvenience is solved by this, considering laser welding as a temporary fixing means, for example, since both the vane and the strap ring are made of copper having extremely high thermal conductivity, welding with high joining strength is performed. Can't get In addition, there is room for further improvement in practical use, such as the fact that welding tends to cause thermal distortion in each part and deformation of the strap ring.

[Object of the Invention]

The present invention has been made in view of the above circumstances,
Provided is a method of manufacturing a magnetron anode assembly which can be stably brazed to an anode vane without using a pressing jig when brazing a strap ring.

[Outline of Invention]

The present invention has an overhang portion having a strap ring joining groove portion 35b having a shape and dimensions substantially corresponding to the cross section of the strap ring inside the anode cylinder formed by rolling a flat plate material and projecting beyond the groove depth portion 35c. A plurality of anode vanes having a strap ring mounting groove 35 having 35d are fixed, and a butt portion of a rounded anode cylinder is opened,
The magnetron anode is characterized in that the strap ring is inserted into the strap ring joining groove portion 35b, the abutting portion of the anode cylinder is closed, the strap ring is press-fitted and fixed in the groove inner portion 35c of the strap ring joining groove portion 35b, and then brazing is performed. It is a method of manufacturing a structure.

Example of Invention

 An embodiment will be described below with reference to the drawings.

The same parts are represented by the same symbols.

As shown in FIGS. 1 and 2, the magnetron anode assembly manufactured according to the present invention has a plurality of copper anode vanes 32, 32 ... Also radially protruding from the inner circumference of an anode cylinder 31 made of copper. It becomes. In each vane, an inner strap ring 33 and an outer strap ring 34 made of copper are mounted in the strap ring mounting grooves 35, 35 ... And electrically short-circuited every other one. Further, each vane is mechanically caulked and fixed by a plurality of projecting pieces 36, 36 for temporarily fixing the vane formed on the anode cylinder 31, and the contact surface with the inner surface of the anode cylinder may be silver solder or the like. It is touched. Reference numeral 37 represents the solder joint. Each strap ring 33, 34 is also brazed and fixed to each vane at a brazing portion indicated by reference numeral 38. Reference numeral 39 in the same figure represents an airtight joint where the abutting portion of the anode cylinder is brazed, and 40 represents an extrusion hole in which a protruding piece is formed. In a space surrounded by the inner end surface of each vane, an electron-emitting cathode assembly (not shown) is arranged at a predetermined interval, and an electron action space is formed between them. Next, a preferable manufacturing procedure of such an anode assembly will be illustrated.

First, a copper flat plate material 41 for an anode cylinder as shown in FIG. 3 is prepared. This is rounded into a cylindrical shape as shown in FIG. The abutting portion 42 which is parallel to the axis is kept in close contact as much as possible. Next, as shown in FIG. 5, a cylinder formed by rolling to facilitate later press fitting of the radiator, that is, an anode cylinder.
A tapered surface 43 is formed on the outer peripheral surface of 31, and step portions for fitting pole pieces (not shown) at both ends to weld a metal container
44 is formed by cutting.

Next, as shown in FIG. 6, the protruding piece 36 is formed from the outer periphery of the anode cylinder 31 by the protruding tool 45. The tool 45 is provided with a protrusion 45a at a predetermined position, which is inserted into the outer peripheral wall of the anode cylinder by about half the thickness thereof, whereby the protruding piece 36 is extruded on the inner periphery. Each protruding piece 36 corresponds to the position where the anode vane (not shown) is to be joined,
Two pairs are formed at the top and bottom. The distance between the pair of projecting pieces is set to be slightly larger than the width dimension of the vane so that the vane can be easily inserted between the projecting pieces later.

On the other hand, separately from that, an anode vane as shown in FIG. 7 is prepared. That is, the vane 32 having the shape shown in the figure is formed by press punching from a copper flat plate having a predetermined thickness. Strap mounting grooves 35, 35 are formed in the upper and lower portions of the vane near the inner end thereof. These grooves 35 are formed with a large-sized groove portion 35a through which the strap ring passes without contact, and a small groove portion 35b with which the strap ring comes into contact with and is locked by this vane. The strap ring joining groove portion 35b has a shape and dimensions substantially corresponding to the cross section of the strap ring. And, in particular, an overhang portion 35d protruding from the inner portion 35c by a dimension t of, for example, about 0.3 mm.
Is formed. This prevents the strap ring from coming off when the strap ring is later mounted in the groove 35b. A slit 46 for connecting an antenna lead is formed on one side surface of the vane. Ten such vanes 32 are prepared for each anode assembly.

On the other hand, from the round bar material 47 made of copper as shown in FIG.
Inner and outer strap rings as shown in FIG.
Form 33, 34. These are formed by bending a round bar into a ring shape so as to have a predetermined diameter, closely forming respective mating portions 33a, 34a, and having a predetermined thickness of silver as a brazing material for brazing on their outer surfaces, Cover with plating.

Next, ten anode vanes 32 shown in FIG. 7 are radially inserted into the anode cylinder 31 shown in FIG. 6 at predetermined positions. Each vane is inserted between the corresponding protruding pieces 36, and is accurately positioned by the vane positioning jig 48 as shown in FIG. 10, so that the outer ends are located between the upper and lower protruding pieces 36. . Then, in this state, the projecting pieces 36 are then squeezed from the outside obliquely as indicated by the arrow by the caulking tool 49, and the vanes are mechanically caulked and fixed by the pair of projecting pieces. This caulked portion is shown by reference numeral 36a in FIG. 10, but the indication of the caulked portion is omitted in other drawings. These vane positioning and caulking steps can be performed by an automatic machine, and it is desirable that the positioning jig 48 be configured as a jig having a movable structure. Thus, when the vane is inserted, the spacing between the positioning jigs is made wider than the thickness of the vane, and when the position is regulated, the workability can be improved by narrowing the gap to a predetermined dimension. In this way, the anode vane 32 can be mechanically and firmly temporarily fixed to the inside of the anode cylinder 31 by caulking the protruding piece 36. When the experiment was carried out in the case where the diameter of the protruding piece was 2 mm and the height was 1 mm, each vane was firmly fixed, and it was not deformed even when trying to bend it by applying a load of about 3 kg to the tip of the inside of the vane.

Next, a pair of strap rings is attached to the groove 35 of each vane. At that time, first, as shown in FIG. 11, the anode cylinder 31 is slightly opened at the rounded butted portion 42 as shown by the arrow, and the outer strap ring 34 shown in FIG. It is attached to this groove inner part 35c. Then, the abutting portion 42 of the anode cylinder 31 is closed by its spring back action, and the outer strap ring 34 is lightly pressed into the groove inner portion 35c. Thus, the strap ring is mounted in the groove as shown in FIG. The strap ring joining groove portion 35b has a shape and size substantially corresponding to the cross section of the strap ring, and further has an overhang portion 35d projecting beyond the inner portion 35c thereof, so that the strap ring is mechanically stable. It is stopped and does not come off. Next, as shown in FIG. 15, the inner strap ring 33 shown in FIG. 14 is slightly opened at its mating portion 33a as shown by the arrow, and a small groove 35b for joining the strap ring is located inside the groove of the vane. Attach to 35c. In this way, if the inner strap ring 33 is opened in the vane slightly larger than the dimension by the overhang portion 35d, it can be easily attached to the inner portion 35c of the groove 35b. If the strap ring is closed by the spring back action, it can be press-fitted mechanically stably and will not come off. In this way, a pair of strap rings is mounted in the groove of the anode vane as shown in FIG. 13 and mechanically temporarily fixed.

Next, as shown in FIG. 16, the contact portion between the anode cylinder and the vane,
In particular, the silver brazing filler metal 50a is placed on the portion sandwiched by the protruding pieces 36, and as shown in FIG. 17, a ribbon-shaped brazing filler metal 50b.
Are inserted between the abutting portions 42 of the anode cylinder. Then, as shown in FIG. 18 and FIG. 19, the ring-shaped outer peripheral regulating jig 51 surrounding the outer peripheral wall of the anode cylinder is installed inside the supporting cylinder portion 52. In this state, put it in a high-temperature brazing furnace and braze each part to be brazed, the strap ring and the vane. In these steps, each vane is only regulated in position by caulking with a protruding piece, and neither the vane positioning jig nor the strap ring holding jig is used. In this way, the magnetron anode assembly shown in FIGS. 1 and 2 is obtained.

In the embodiment described above, the strap mounting groove has an arc shape, but the present invention is not limited to this, and the strap mounting groove 35 may be formed in a rectangular shape as shown in FIGS. 20 to 22. Then, the strap rings 33, 34 having a rectangular cross section are lightly press-fitted into the groove inner portions 35c of the joining grooves, and then brazed without using a holding jig.

Instead of silver-plating the strap ring, a brazing material may be placed and brazed later.

〔The invention's effect〕

According to this invention, the following effects can be obtained. That is, according to the present invention, the strap ring mounting groove of the plurality of anode vanes provided on the inner circumference of the anode cylinder has a strap ring joining groove portion 35b having a shape and a dimension substantially corresponding to the cross section of the strap ring. It is formed so as to have an overhang portion 35d protruding from the groove inner portion 35c, and is a magnetron anode structure in which a strap ring is attached and brazed to the groove inner portion 35c, and the manufacturing method thereof is A strap having a groove 35b for joining a strap ring, which has a shape and dimensions substantially corresponding to the cross section of the strap ring, and an overhang portion 35d projecting beyond the groove depth 35c, inside the anode cylinder formed by rolling and molding a flat plate material. For fixing a plurality of anode vanes that have a groove for ring attachment and opening the abutting part of the rounded anode cylinder to join the strap ring In the method of manufacturing a magnetron anode assembly, which comprises inserting a strap ring into the portion 35b, closing the abutting portion of the anode cylinder, press-fitting the strap ring into the groove depth 35c of the strap ring joining groove portion 35b, and then brazing. is there. As a result, the strap ring is mechanically locked to the inner part of the joining groove in a stable manner and brazed in that state, so that it does not cause extra thermal distortion and is hardly deformed. In addition, since the pressing jig does not have to be used for the brazing, the manufacturing cost can be reduced and the workability is excellent. Therefore, it is highly productive.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an essential part showing an embodiment of the present invention.
The figure is a perspective view of the main part thereof, FIGS. 3 and 4 are perspective views showing the anode material in the manufacturing process, FIG. 5 is a half sectional view showing the anode cylinder in the subsequent step, and FIG. 6 is the subsequent step. FIG. 7 is a perspective view of the anode vane, FIG. 8 and FIG.
The figure shows a perspective view and a plan view of the strap ring,
The figure is a perspective view of the main parts in the subsequent steps, FIGS. 11 and 12 are top views of the subsequent steps, FIG. 13 is a longitudinal sectional view of the main parts in the subsequent steps, and FIGS. 14 and 15 are inner straps. FIG. 16 is a top view of the ring, FIG. 16 is a perspective view of a main part in a subsequent step, FIG. 17 is a perspective view showing a brazing filler metal, and FIGS. 18 and 19 are cross-sectional views and vertical cross sections of a main part in the brazing step. FIGS. 20 and 21 are a half sectional view and a perspective view of a main portion showing another embodiment of the present invention, and FIG. 22 is a vertical sectional view of the main portion. 31 …… Anode cylinder, 32 …… Anode vane, 33,34 …… Strap ring, 35 …… Strap ring mounting groove, 35b…
… Strap ring joint groove, 35c …… Deep groove, 3
5d …… Overhang part, 38 …… Brazed joint.

Claims (1)

[Claims] 1. An overhang having a groove portion 35b for joining a strap ring, which has a shape and dimensions substantially corresponding to the cross section of the strap ring, and which protrudes beyond the groove inner portion 35c, inside an anode cylinder formed by rolling a flat plate material. A plurality of anode vanes having a strap ring mounting groove 35 having a portion 35d are fixed, then the butted portion of the rounded anode cylinder is opened, and the strap ring is inserted into the strap ring joining groove portion 35b. A method for manufacturing a magnetron anode assembly, characterized in that a butt portion of the anode cylinder is closed, a strap ring is press-fitted and fixed in a groove inner portion 35c of the strap ring joining groove portion 35b, and then brazing is performed.