JP2009081018A - Magnetron, manufacturing device of magnetron, and manufacturing method of magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cut off an amount of use of materials without degrading load stability of a magnetron. <P>SOLUTION: To a vane 2 of the magnetron provided with an anode cylinder 1 extended in a cylinder shape along a center axis 30, a spiral cathode 5 arranged at the center axis 30, and a pair of end hats 6, 7 fastened to either end of the cathode 5, a loose end 31 of a main body part 34 extended in a flat shape from the loose end 31 parallel with the center axis 30 and opposed to the cathode 5 to a fixed end 35 fastened to an inner face of the anode cylinder 1 is to be equipped with burrs 33 in order to be extended along the center axis 30. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetron, a magnetron manufacturing apparatus, and a magnetron manufacturing method.

  A general magnetron for microwave ovens that oscillates radio waves in the 2450 MHz band includes an anode cylinder and a plurality of flat plate vanes. The vanes are arranged radially inside the anode cylinder. The vanes are connected to each other in the circumferential direction by a pair of large and small strap rings brazed to the upper and lower ends of the vane. In the electron action space surrounded by the free ends of the plurality of vanes, a spiral cathode is disposed along the axis of the anode cylinder. Both ends of the spiral cathode are fixed to the output side end hat and the input side end hat, respectively. Further, a substantially funnel-shaped output side and input side pole piece are fixed to both ends of the anode cylinder, respectively.

  The anode cylinder and vane are joined by brazing, but are usually temporarily fixed before brazing. For example, the vane is arranged in a radial slit provided in the base jig, and the anode cylinder, the vane, and the center jig are temporarily fixed to each other by press-fitting the center jig into the center thereof.

Magnetrons for microwave ovens are required to be miniaturized from the viewpoint of miniaturization of heating equipment itself, resource saving, and cost reduction. Various metal materials are used for the magnetron. In particular, a considerable amount of copper or copper alloy is used for the anode part such as the anode cylinder, vane, strap and antenna. For this reason, attempts have been made to change to other materials or to reduce the size.
Japanese Patent Publication No. 5-035531

  Changing to a material other than the copper alloy of the anode part has various problems in manufacturing as well as electrical and thermal constraints, and is difficult to put into practical use. Further, for the purpose of reducing the size of the anode part, material thinning, diameter reduction, axial shortening, and the like are performed, but the influence on characteristics and heat dissipation is great. In particular, shortening in the axial direction has a great effect on reducing the material cost as well as reducing the diameter, that is, reducing the amount of material used. 1).

  If the amount of material used is simply reduced and the working space is ensured, a structure in which only the vane working space side end surface is elongated in the axial direction and the other portions to the anode cylindrical joint portion may be shortened. However, since vanes are usually made by pressing, the raw materials are the same as before, and the amount of scrap increases, so material efficiency deteriorates and it is difficult to reduce costs.

  On the other hand, even with the magnetron that has been improved as disclosed in Patent Document 1, there is a demand for further improving the load stability, but it is difficult to achieve without increasing the cost without sacrificing other characteristics.

  Accordingly, an object of the present invention is to reduce the amount of material used without degrading the load stability of the magnetron.

  In order to solve the above-described problems, the present invention provides a magnetron, an anode cylinder extending in a cylindrical shape along a central axis from the input side to the output side, a spiral cathode disposed on the central axis, and the cathode A pair of end hats fixed to both ends, a main body extending in a flat plate shape from a free end parallel to the central axis and facing the cathode to a fixed end fixed to the inner surface of the anode cylinder, and the free end A plurality of vanes having a burr formed so as to extend along the central axis, and at least a pair of strap rings connecting the vanes to every other circumferential direction. It extends in the direction of.

  Further, the present invention provides an anode cylinder extending in a cylindrical shape along a central axis from the input side to the output side, a spiral cathode disposed on the central axis, and a pair of ends fixed to both ends of the cathode A hat, a plurality of vanes having a body portion extending in a flat plate shape from a free end parallel to the central axis and facing the cathode to a fixed end fixed to the inner surface of the anode cylinder, and the vane in the circumferential direction In a magnetron manufacturing apparatus comprising at least a pair of strap rings connected to each other, an anode mounting surface on which the anode cylinder is mounted, a vane mounting surface on which the vane is mounted, and the vane mounting surface A straight jig passing through the center of the center hole, having a base jig in which an inscribed circle of the free end and a center hole having the same outer diameter are formed at the center of the base, and a cylindrical portion having the same inner diameter and outer diameter of the center hole A movable center along And a notch portion is formed around the center hole of the vane mounting surface and having a width substantially the same as the plate thickness of the main body portion and recessed in the movement direction of the center jig. And

  Further, the present invention provides an anode cylinder extending in a cylindrical shape along a central axis from the input side to the output side, a spiral cathode disposed on the central axis, and a pair of ends fixed to both ends of the cathode A hat, a plurality of vanes having a body portion extending in a flat plate shape from a free end parallel to the central axis and facing the cathode to a fixed end fixed to the inner surface of the anode cylinder, and the vane in the circumferential direction A temporary placement step of temporarily placing the anode cylinder and the main body portion from the inner surface of the anode cylinder toward the central axis, in a method of manufacturing a magnetron comprising at least a pair of strap rings connected every other; After the temporary placing step, a burr is formed such that a cylinder having the same outer diameter as the inscribed circle of the free end is relatively pushed along the central axis so as to extend the free end along the central axis. Forming process, Characterized in that it Bei.

  According to the present invention, the amount of material used can be reduced without degrading the load stability of the magnetron.

  Embodiments of a magnetron according to the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same or similar structure, and the overlapping description is abbreviate | omitted.

  FIG. 2 is a longitudinal sectional view of an embodiment of a magnetron according to the present invention.

  The magnetron of the present embodiment has an anode cylinder 1, a cathode 5, a pair of end hats 6, 7 and a pair of pole pieces 8, 9 arranged along the same axis (center axis 30). The magnetron has a plurality of flat vanes 2. The vane 2 extends radially from the free end 31 parallel to the central axis 30 and facing the cathode 5 to the inner surface of the anode cylinder 1.

  The anode cylinder 1 extends in a cylindrical shape along the central axis 30. The vane 2 extends radially from the vicinity of the central axis 30 and is fixed to the inner surface of the anode cylinder 1. The vanes 2 are each formed in a substantially rectangular plate shape. The free end 31 of the vane 2 on the side not fixed to the inner surface of the anode cylinder 1 is disposed on the same cylindrical surface extending along the central axis 30, and this cylindrical surface is called a vane inscribed cylinder. The plurality of vanes 2 are connected to each other in the circumferential direction by strap rings 3 and 4 that are paired in large and small brazed to the upper and lower ends of the vane.

  The cathode 5 has a spiral shape and is disposed inside the vane inscribed cylinder, which is an electron action space, and is disposed on the central axis of the anode cylinder 1. Further, both ends of the cathode 5 are fixed to the end hats 6 and 7, respectively. The end hats 6 and 7 are disposed outside the central axis 30 with respect to the vane 2, for example.

  The pair of pole pieces 8 and 9 are each formed in a funnel shape having a through hole 32 at the center. The center of the through hole 32 is located on the central axis 30. Each of the pole pieces 8 and 9 is formed so as to spread from the through hole 32 toward the outside of the central shaft 30 with respect to the space between the end hats 6 and 7. The outer diameters of the pole pieces 8 and 9 are formed substantially the same as the diameter of the anode cylinder 1. The outer peripheral portions of the pole pieces 8 and 9 are fixed to both ends of the anode cylinder 1 respectively. Further, the pair of pole pieces 8 and 9 are arranged with a space between the end hats 6 and 7 interposed therebetween.

  Further, cylindrical metal sealing bodies 10 and 11 are fixed to the pole pieces 8 and 9, respectively. Each metal sealing body 10, 11 is also in contact with one end of the anode cylinder 1.

  An output-side ceramic 12 is joined to the end of the output-side metal seal 10 opposite to the pole piece 8. An exhaust pipe 13 is joined to the end of the output side ceramic 12 opposite to the metal seal. An antenna 14 is derived from the vane 2. The antenna 14 passes through the output-side pole piece 8, extends in the output portion, and the tip is clamped and fixed by the exhaust pipe 13. The entire exhaust pipe 13 is covered with a cap 15.

  An input-side ceramic 16 is joined to the end of the input-side metal seal 11 opposite to the pole piece 9. Two support rods 17 and 18 are connected to the cathode 5 via end hats 6 and 7. The support rods 17 and 18 are led out of the pipe through, for example, the relay plate 19 and connected to the input terminal 20.

  Further, the magnets 21 and 22 and the yokes 23 and 24 are disposed so as to surround such an oscillating unit main body to form a magnetic circuit. Further, an exterior is formed by a radiator 25 for cooling the oscillation unit main body, a filter 26 connected to the input side, and a box 27 surrounding the filter 26.

  FIG. 1 is an enlarged longitudinal sectional view in the vicinity of a vane in the present embodiment.

  In the magnetron of the present embodiment, the vane 2 has a main body portion 34 and a burr 33. The main body 34 extends from the inner surface of the anode cylinder 1 toward the central axis 30. The burr 33 is formed so as to extend the free end 31 of the main body 34 along the central axis 30.

  As described above, in the present embodiment, since the burr 33 is formed on the vane 2, the length of the portion of the vane 2 facing the electron emission surface of the cathode 5 is longer by the burr 33. For this reason, the working space becomes substantially longer, and the load stability is improved. For example, in the magnetron having the structure disclosed in Patent Document 1, when the axial height of the vane 2 is shortened by 0.5 mm, the load stability is reduced by about 0.1 A. However, by forming a burr with a height of 0.5 mm, a load stability equivalent to a vane with a height of 9.5 mm can be realized with a vane with a height of 9.0 mm. In this case, the amount of material used can be reduced by about 5%.

  Therefore, in this Embodiment, the usage-amount of material can be reduced, without degrading the load stability of a magnetron. Moreover, since the vane 2 can be reduced in size without degrading the load stability, the entire magnetron can also be reduced in size. Or even if it is a case where the whole magnetron is not reduced in size, by forming the burr | flash 33 in the vane 2, load stability can be improved, without making a big design change and cost increase.

  Moreover, in this Embodiment, the main-body part 34 of the vane 2 has the same shape altogether. The main body 34 has a first side 61 and a second side 62 that extend from the free end 31 to the fixed end 35 and face each other. The main body 34 is fixed to the anode cylinder 1 with a fixed end 35.

  In the vicinity of the first side 61, a connecting portion 63 with the small-diameter strap ring 4 is formed. In the vicinity of the second side 62, a penetrating portion 64 of the strap ring 4 having a small diameter is formed. In this embodiment, since the vanes are connected by the large and small strap rings 3 and 4, the connecting portion 63 of the large diameter strap ring 3 is provided outside the connecting portion 63 and the through portion 64 of the small diameter strap ring 4. And a penetration part is also formed. An antenna connection portion 65 for connecting the antenna 14 is formed on the first side. Note that nothing is connected to the antenna connecting portion 65 except for the vane 2 to which the antenna 14 is connected.

  Next to the main body 34 in which the first side 61 is located on the input side (lower side in FIG. 1), the main body 34 in which the second side is located on the input side is disposed. In other words, the same main body 34 is arranged while being turned upside down alternately.

  Next, a method for manufacturing this magnetron will be described.

  FIG. 3 is an enlarged longitudinal sectional view of a part of the magnetron manufacturing apparatus according to the present embodiment. FIG. 3 also shows a magnetron being assembled.

  This manufacturing apparatus has a table jig 40 and a center jig 50.

  The base jig 40 has an anode mounting surface 41 and a vane mounting surface 42. The anode mounting surface 41 is formed, for example, in a ring shape so that the anode mounting surface 41 can be mounted so that the axis of the anode 1 faces in the normal direction. The vane placement surface 42 is arranged, for example, in the normal direction from the anode placement surface 41 so that the vane 2 can be placed at a predetermined position with respect to the anode 1 when the anode 1 is placed on the anode placement surface 41. It is formed to protrude. A cylindrical center hole 43 that is recessed in the normal direction is formed in the central portion of the vane installation surface 42.

  The center jig 50 has a conical tip portion 51 and a cylindrical portion 52 integrated with the tip portion 51. The outer diameter of the column part 52 is equal to the diameter of the vane inscribed cylinder. The center axis of the center jig 50 passes through the center of the center hole 43. The center jig 50 is formed to be movable along a straight line passing through the center of the center hole 43. A straight line passing through the center of the center hole 43 is the central axis 30 of the magnetron.

  Further, around the center hole 43, a notch 44 is formed which is substantially the same width as the plate thickness of the main body 34 and is recessed from the vane mounting surface 42 in the moving direction of the center jig 50.

  First, the anode cylinder 1 is placed on the anode installation surface 41 of the table jig 40. Next, a main body 34 that is slightly longer in the radial direction than the main body 34 of the finished product is prepared. Using a slit (not shown) that defines the position of the vane 2, the main body portions 34 having the same shape are alternately arranged upside down on the vane installation surface 42. In such a temporarily placed state, the inscribed circle of the free end 31 of the main body 34 is slightly smaller in diameter than the inscribed circle of the finished free end 31. The anode cylinder 1 may be disposed after the main body portion 34 is disposed.

  Thereafter, the center jig 50 is press-fitted toward the center hole 43. As a result, the anode 1 and the vane 2 are brought into a pressure contact state and temporarily fixed. At this time, the center jig 50 is press-fitted so as to push the inner end face of the vane slightly while being sharpened, and a space is formed by a notch 44 at the lower end of the vane 2. A burr 33 is formed so as to extend along 30. In other words, the burr 33 is a tongue-like portion where the vicinity of the free end 31 of the main body 34 protrudes due to the movement of the center jig 50.

  The shape and size of the burr 33 can be adjusted as appropriate depending on the shape of the center jig 50 and the notch 44 and the hardness and shape of the anode cylinder 1 and the vane 2. For example, even in a material corresponding to oxygen-free copper specified in JIS C1020, which is generally used for vane 2, the hardness is changed by changing the annealing temperature of the material, and a burr 33 is easily generated. It can be replaced with soft materials.

  After temporarily fixing the vane 2 to the anode 1, the large and small strap rings 3 and 4 are disposed above and below the vane 2, and the antenna 14 is disposed on one of the vanes 2. Thereafter, the magnetron is completed through processes such as joining (brazing) the anode cylinder 1, the vane 2, the strap rings 3 and 4, and the antenna 14 with a brazing material.

  The main body 34 is formed by punching from a large flat plate such as copper. When a vane having a shape corresponding to the burr 33 is directly formed from a large flat plate, a gap is generated between adjacent vanes when a plurality of main body portions are formed from the same large flat plate, which is wasteful. However, when the burr 33 is formed later on the main body portion 34 as in the present embodiment, only the main body portion 34 needs to be formed first, so there is little waste of material. In the present embodiment, the main body portions 34 having the same shape are alternately arranged upside down. However, when a vane having a shape corresponding to the burr 33 is formed in advance, the main body portions 34 are arranged in two directions. It is necessary to form two types of vanes having a shape corresponding to the burr 33, which is not efficient.

  The length of the burr 33 is preferably shorter than the shortest distance between the main body portion 34 of the vane 2 and the adjacent end hat 7. By forming the vane 2 in this way, even if the burr 33 falls down so as to approach the cathode 5 during the process after the burr 33 is formed or when the magnetron is used, a short circuit with the cathode 5 hardly occurs. For this reason, possibility that the serious defect called a short circuit will arise becomes low.

  If the width of the burr 33 on the surface facing the working space is wider than the thickness of the vane 2, the capacity component with the adjacent vane 2 becomes large, which may cause problems such as frequency variation and efficiency reduction. Conversely, when the width of the burr 33 is too narrow, not only can the load stability be improved much, but the burr 33 is likely to be deformed or dropped off, causing a magnetron failure. For this reason, it is desirable that the width of the burr 33 is wider than ½ of the thickness of the vane 2 at least at the base portion. Further, since the burr is formed at the time of manufacturing the anode structure, the burr is not deformed at the time of storing and supplying the parts, and the supply is not hindered.

  Moreover, the precision of the shape and dimension of the burr | flash 33 can be improved by forming the notch part 44 of the stand jig 40 in a suitable shape. For example, if the notch 44 is provided with a groove having the same width as the thickness of the vane 2 and having a predetermined depth, when the center jig 50 is press-fitted, the burr 33 is formed between the groove and the center jig 50. Since the space is limited to the enclosed space, the uniform burr 33 can be formed without the width and length exceeding the groove dimensions.

  In this embodiment, the burrs 33 are formed when the center jig 50 is press-fitted. However, the burrs 33 may be formed after temporarily fixing and brazing. In this case, the center jig 50 may be fixed, and the assembly of the anode cylinder 1 and the main body 34 of the vane 2 after brazing may be moved in the axial direction of the center jig 50. At this time, the entire anode structure is very soft compared to before brazing, so that the burr formation itself is easy. However, care must be taken because other parts are easily deformed during the formation.

  The above description is merely an example, and the present invention is not limited to the above-described embodiment, and can be implemented in various forms.

FIG. 3 is an enlarged longitudinal sectional view in the vicinity of an anode cylinder in an embodiment of a magnetron according to the present invention. It is a longitudinal cross-sectional view of one embodiment of the magnetron according to the present invention. It is the longitudinal cross-sectional view which expanded a part of manufacturing apparatus of the magnetron in one Embodiment of the magnetron based on this invention.

Explanation of symbols

1 ... anode cylinder, 2 ... vane, 3 ... strap ring (large), 4 ... strap ring (small), 5 ... cathode, 6 ... end hat (output side), 7 ... end hat (input side), 8 ... pole Piece (output side), 9 ... Pole piece (input side), 10 ... Metal sealing body (output side), 11 ... Metal sealing body (input side), 12 ... Output side ceramic, 13 ... Exhaust pipe, 14 ... Antenna, 15 ... Cap, 16 ... Input side ceramic, 17 ... Support rod, 18 ... Support rod, 19 ... Relay plate, 20 ... Input terminal, 21 ... Magnet, 22 ... Magnet, 23 ... Yoke, 24 ... Yoke, 25 ... Radiator, 26 ... Filter, 27 ... Box, 30 ... Center axis, 31 ... Free end, 32 ... Through hole, 33 ... Burr, 34 ... Main body, 35 ... Fixed end, 40 ... Base jig, 41 ... Anode mounting surface 42 ... Down mounting surface, 44 ... notch part, 50 ... center jig, 51 ... tip portion, 52 ... cylindrical portion

Claims (5)

An anode cylinder extending in a cylindrical shape along a central axis from the input side toward the output side;
A spiral cathode disposed on the central axis;
A pair of end hats secured to both ends of the cathode;
A body portion extending in a flat plate shape from a free end parallel to the central axis and facing the cathode to a fixed end fixed to the inner surface of the anode cylinder, and the free end is formed to extend along the central axis A plurality of vanes having burr;
At least a pair of strap rings connecting the vanes to every other circumferential direction;
And the burrs all extend in the same direction.   All the main body portions have first and second sides extending from the free end to the fixed end and facing each other, and a connection portion with the strap ring is formed in the vicinity of the first side, The strap ring penetrating part is formed in the vicinity of the second side, and the second side is adjacent to the main body part where the first side is located on the input side. The magnetron according to claim 1, wherein the main body located on the input side is arranged. An anode cylinder extending in a cylindrical shape along a central axis from the input side to the output side, a spiral cathode disposed on the central axis, a pair of end hats fixed to both ends of the cathode, and the central axis A plurality of vanes having a body portion extending in a flat plate shape from a free end parallel to the cathode to a fixed end fixed to the inner surface of the anode cylinder, and at least a pair connecting the vanes to every other circumferential direction In a magnetron manufacturing apparatus comprising:
An anode mounting surface on which the anode cylinder is mounted, a vane mounting surface on which the vane is mounted, and a central hole having the same outer diameter as the inscribed circle of the free end are formed at the center of the vane mounting surface. With the pedestal jig,
A center jig having a cylindrical portion having an inner diameter equal to the outer diameter of the center hole, and movable along a straight line passing through the center of the center hole;
And a notch that is substantially the same width as the plate thickness of the main body and is recessed in the moving direction of the center jig is formed around the central hole of the vane mounting surface. Magnetron manufacturing equipment. An anode cylinder extending in a cylindrical shape along a central axis from the input side to the output side, a spiral cathode disposed on the central axis, a pair of end hats fixed to both ends of the cathode, and the central axis A plurality of vanes having a body portion extending in a flat plate shape from a free end facing the cathode to a fixed end fixed to the inner surface of the anode cylinder, and at least a pair connecting the vanes to every other circumferential direction In the manufacturing method of the magnetron provided with the strap ring,
A temporary placing step of temporarily placing the anode cylinder and the main body portion from the inner surface of the anode cylinder toward the central axis;
After the temporary placing step, a burr is formed such that a cylinder having the same outer diameter as the inscribed circle of the free end is relatively pushed along the central axis so as to extend the free end along the central axis. Forming process;
A method for producing a magnetron, comprising:   All the main body portions have first and second sides extending from the free end to the fixed end and facing each other, and a connection portion with the strap ring is formed in the vicinity of the first side, In the vicinity of the second side, the strap ring penetrating portion is formed in the same shape, and the temporary placing step is arranged next to the main body portion where the first side is located on the input side. 5. The method according to claim 4, further comprising a step of arranging the main body portion having a second side positioned on the input side, and the step of connecting the vane and the strap ring after the temporary placement step. The manufacturing method of the magnetron of description.

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