Magnetron

Abstract

The invention provides a magnetron capable of preventing coil damage and suppressing oscillation stop caused by abnormal oscillation. The magnetron is a high-output type magnetron for industry; all the plate-shaped blades belonging to the first plate-shaped blade group and all the plate-shaped blades belonging to the second plate-shaped blade group have a number which is set so as to enlarge the dissociation between the fundamental waves generated by resonance in the resonant cavity and useless radiation in the vicinity of the front ends in the direction of the central axis during the manufacturing stage of the magnetron by performing a test operation, and the number of the plate-shaped blades belonging to the first plate-shaped blade group and the number of the plate-shaped blades belonging to the second plate-shaped blade group are set. At least three or more through holes of the same number, n being an odd number starting from 1, penetrate the nth grading ring so as to be in contact with the nth through hole of all the plate-shaped blades belonging to the first plate-shaped blade group; the (n + 1) th grading ring penetrates through the (n + 1) th through hole of all the plate-shaped blades belonging to the second plate-shaped blade group in a manner of being in contact with the (n + 1) th through hole.

Description

Technical Field

[0001] The invention relates to a magnetron. Background Art

[0002] The magnetron uses a belt-shaped ring to equalize the potential of the plate-shaped blades and to suppress the influence of unnecessary radiation that becomes noise.

[0003] Patent document 1 discloses a magnetron, characterized in that it comprises: an anode cylinder extending along a central axis; a plurality of plate-shaped blades joined to the anode cylinder and extending toward the central axis to form an inscribed circle with a free end surrounding the central axis; a large-diameter band ring joined to a notch portion provided on the side between the anode cylinder and the free end of the blade so that the blades are alternately short-circuited; and a small-diameter band ring having a smaller diameter than the large-diameter band ring, an inner diameter of the large-diameter band ring being equal to an outer diameter of the small-diameter band ring, and being arranged in the notch portion with steps relative to each other along the central axis direction.

[0004] Prior art literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2012-169169 Summary of the invention

[0006] In the technology disclosed in Patent Document 1, the inner diameter of the large-diameter belt-shaped ring is equal to the outer diameter of the small-diameter belt-shaped ring, and the large-diameter belt-shaped ring and the small-diameter belt-shaped ring are arranged on the blade end surface with a step so as not to contact each other. By making the inner diameter of the large-diameter belt-shaped ring equal to the outer diameter of the small-diameter belt-shaped ring, the amount of waste can be reduced when the belt-shaped ring is punched from a plate, thereby improving the material efficiency of the belt-shaped ring and reducing the manufacturing cost.

[0007] However, in the high-power industrial magnetron, there are two problems in the method of installing the belt-shaped ring (hereinafter referred to as the voltage-equalizing ring) of Patent Document 1.

[0008] The first problem is to provide a notch on the side of the plate-like blades in the pressure-equalizing ring, thereby forming a structure including a large-diameter pressure-equalizing ring with a joint configuration that alternately short-circuits the plate-like blades, and a small-diameter pressure-equalizing ring with a smaller diameter than the large-diameter pressure-equalizing ring. However, in this structure, the fundamental wave microwave is transmitted in the vacuum tube and flows toward the coil side, which sometimes burns the coil.

[0009] The second problem is that it is impossible to completely suppress the influence of unwanted radiation on the fundamental wave, which sometimes causes abnormal oscillation.

[0010] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a magnetron capable of preventing coil damage and suppressing oscillation stop due to abnormal oscillation.

[0011] In order to achieve the above-mentioned purpose, the magnetron of the present invention is a high-output industrial magnetron, comprising: an anode cylinder; a plurality of plate-like blades, each of which has one end fixed to a plurality of different fixing portions on the inner wall surface of the anode cylinder, and each of which has the other end extending from the fixing portion toward the central axis of the magnetron; and a predetermined number of equalizing rings, which are arranged on the inner side of the anode cylinder, the plurality of plate-like blades constitute a first plate-like blade group consisting of a collection of the plate-like blades in every other row in a clockwise or counterclockwise direction with the plate-like blades at a predetermined position as the starting position, and a second plate-like blade group consisting of a collection of the plate-like blades other than the first plate-like blade group, the first plate-like blades belonging to All the plate-like blades of the sheet group and all the plate-like blades belonging to the second plate-like blade group have at least three through holes of the same number near the front end in the direction of the central axis, which are set in a manner to implement a test action during the manufacturing stage of the magnetron and to expand the dissociation of the fundamental wave generated by resonance in the resonance cavity and the useless radiation, and n is set to a numerical value representing an odd number starting with 1, and the nth pressure-equalizing ring is penetrated in a manner to contact the nth through hole of all the plate-like blades belonging to the first plate-like blade group, and the n+1th pressure-equalizing ring is penetrated in a manner to contact the n+1th through hole of all the plate-like blades belonging to the second plate-like blade group. Other embodiments of the present invention will be described in the embodiments described later.

[0012] The effects of the present invention are as follows.

[0013] According to the present invention, it is possible to prevent the coil from being damaged and suppress the oscillation stop caused by the occurrence of abnormal oscillation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram showing the structure of a high-power industrial magnetron according to the present embodiment.

[0015] Figure 2A This is a diagram showing the arrangement of a plate-like blade having three through holes.

[0016] Figure 2B This is a diagram showing the arrangement of the plate-like blades when there are four through holes.

[0017] Figure 3A This is a diagram showing another arrangement in which the number of through holes in the plate-like blade is three.

[0018] Figure 3B It is a diagram showing another arrangement in the case where the number of through holes in the plate-like blade is four.

[0019] Figure 4 This is a diagram showing the arrangement of plate-like blades on the anode cylinder.

[0020] Figure 5 It is a diagram showing the arrangement method of the through holes and the pressure equalizing ring.

[0021] Figure 6 This is a graph showing the correlation between the strip rate and the unwanted radiation.

[0022] Figure 7 It is a diagram showing the effect of three pressure equalizing rings.

[0023] Figure 8 It is a figure which shows that the pressure equalizing rings are connected to each other.

[0024] Fig. 9 This is a diagram showing a detailed structure of a high-power industrial magnetron according to the present embodiment.

[0025] In the figure: 51—cathode filament, 52—plate-like blades, 52h—through hole, 52g1—first plate-like blade group, 52g2—second plate-like blade group, 52f—fixing part, 53—anode cylinder, 54, 54a—permanent magnet, 55, 55a—magnetic pole, 56, 56a—magnetic yoke, 57—antenna lead, 58—antenna block, 59—vacuum tube, 61—output side ceramic, 63—action space, 64—equalizing ring (belt ring), 66, 67—upper and lower sealing metals, 68, 68a—upper and lower anode Pole plate, 69—output part, 70—magnetic circuit part, 71—upper side end shield, 72—lower side end shield, 73—cathode lead (center lead), 74—cathode lead (side lead), 75—input side ceramic, 76—terminal plate, 77—cooling mechanism, 77a—cooling water passage, 78—cathode part, 79—anode part, 80—exhaust pipe, 81—choke coil (coil), 82—through capacitor, 83—filter housing, 84—cover, 85—filter structure, 100—magnetron. DETAILED DESCRIPTION

[0026] Embodiments for carrying out the present invention will be described in detail with reference to the drawings as appropriate.

[0027] Figure 1 1 is a diagram (cross-sectional view) showing the structure of a high-power industrial magnetron 100 of the present embodiment. The high-power industrial magnetron 100 is configured to include: an anode cylinder 53; a plurality of plate-like blades 52, each of which has one end fixed to a plurality of different fixing portions 52f on the inner wall surface of the anode cylinder 53 (see FIG. 1 ); Figure 4), the other end of each of which extends from the fixed portion 52f toward the central axis; a cathode filament 51, which is arranged in the center of the anode cylinder 53; and permanent magnets 54, 54a. A heater is wound on the cathode filament 51, and by applying a predetermined current to it, thermal electrons are emitted from the cathode filament 51. The thermal electrons are attracted to the side of the anode cylinder 53, but are rotated around the cathode by the magnetic field formed by the magnet, and resonate in the cavity formed by the inner wall surface of the anode cylinder 53 and the plurality of plate-like blades 52, namely the resonance cavity (described later), and their energy is extracted from the output portion 69 (antenna) as microwaves. For details, refer to Figure 2A to Figure 5 As will be described later, through holes 52h are provided at the ends of the plurality of plate-like blades 52 (for example, see Figure 2A ), forming a structure that passes through the pressure equalizing ring 64.

[0028] Industrial magnetrons with outputs of 2 to 10 kW are generally called low-output types, and those with outputs greater than 10 kW are called high-output types. Also, household magnetrons with outputs of several kW are sometimes called low-output types, and those with outputs greater than several kW are called high-output types.

[0029] Fig. 9 1 is a diagram showing the detailed structure of a high-power industrial magnetron according to the present embodiment. In the magnetron 100, 51 is a cathode filament (straight-heated spiral cathode) that is a thermal electron emission source, 52 is a plurality of plate-like vanes (anode vanes), and 53 is an anode cylinder.

[0030] 54 and 54a are annular permanent magnets, 55 and 55a are magnetic poles, 56 and 56a are yokes. 57 is an antenna lead, 58 is a cylindrical antenna block, 61 is an output side ceramic (insulator), 63 is an action space, 64 is a grading ring, 66 and 67 are rod-shaped upper and lower sealing metals, 68 and 68a are upper and lower anode plates, and 69 is an output unit. The output unit 69 is composed of an antenna lead 57 and an antenna block 58. In addition, the antenna lead 57 and the antenna block 58 are joined by silver brazing or arc welding.

[0031] Reference numeral 70 denotes a magnetic circuit portion, which includes permanent magnets 54, 54a, magnetic poles 55, 55a, and magnetic yokes 56, 56a, which are magnetic generating sources. Reference numeral 71 denotes an upper end shield (also referred to as an output end shield), reference numeral 72 denotes a lower end shield (also referred to as an input end shield), reference numeral 73 denotes a center lead of a cathode lead, and reference numeral 74 denotes a side lead of a cathode lead.

[0032] Reference numeral 75 denotes an input side ceramic, and reference numeral 78 denotes a cathode portion. Reference numeral 78 denotes a cathode filament 51 that is a thermal electron emission source, an upper end shield 71, a lower end shield 72, and cathode leads 73, 74, etc. Reference numeral 79 denotes an anode portion, and reference numeral 79 denotes anode portion 79 that is fixedly connected to a plurality of plate-like blades 52 and an anode cylinder 53 by brazing or the like, or is formed integrally with the anode cylinder 53 by extrusion molding. Reference numeral 76 denotes a terminal plate, and reference numeral 80 denotes an exhaust pipe.

[0033] In the magnetron 100 having such components, the yokes 56 and 56a constitute the magnetic circuit part 70, but are also a frame that accommodates the permanent magnets 54 and 54a, the magnetic poles 55 and 55a, the antenna lead 57, the cathode part 78, and the anode part 79, and are arranged on the output side of the microwave, and are also used as a coupling component for coupling with an external mechanism not shown. The frame is configured such that one yoke 56 is in a box shape with an opening on the lower surface, and the other yoke 56a is in a cover shape that blocks the opening. In addition, the yokes 56 and the yokes 56a are screwed to each other by screws 205, and the yokes 56 are screwed to the cooling mechanism 77 by screws 205a.

[0034] Magnetic poles 55, 55a made of a ferromagnetic material such as soft iron and cylindrical permanent magnets 54, 54a are arranged above and below the anode cylindrical body 53. The magnetic flux generated by the permanent magnets 54, 54a enters the action space 63 formed between the cathode filament 51 and the plate-like blade 52 through the magnetic poles 55, 55a, and applies a necessary DC magnetic field in the vertical direction of the magnetron 100, that is, in the axial direction.

[0035] The following effects are produced by this DC magnetic field. That is, when the main axis of the magnetron 100 is set vertically relative to the horizontal plane, if a magnetic flux is applied in the vertical direction (axis direction) to the electrons flying in the horizontal direction from the cathode filament 51 toward the plate-like blade 52, a Lorentz force is exerted on the electrons. Due to this Lorentz force, the electrons fly while spiraling in the horizontal direction, forming a high-frequency electric field on the plate-like blade 52.

[0036] The cathode filament 51 emits electrons when a negative high voltage of 4kV to 8kV is applied. The electrons are subjected to the electric field and the magnetic field as described above and form a high-frequency electric field in each plate-shaped blade 52 while performing a spiral motion. The formed high-frequency electric field is output from the antenna block 58 to an external device (not shown) through the antenna lead 57.

[0037] In addition, considering the electron emission characteristics and processability, the cathode filament 51 generally uses a tungsten wire containing about 1% thorium oxide (ThO2), and is supported by the upper end shield 71 and the lower end shield 72 and the cathode leads 73 and 74. From the viewpoint of heat resistance and processability, the cathode leads 73 and 74 generally use molybdenum (Mo) and are connected to the choke coil 81 via a terminal plate 76 brazed on the upper surface of the input side ceramic 75 with silver solder or the like.

[0038] A filter structure 85 composed of a filter case 83 supporting a choke coil 81 and a through capacitor 82 and a cover 84 closing the filter case 83 is installed at the lower part of the magnetron 100. The choke coil 81 connected to the terminal plate 76 and the through capacitor 82 constitute an LC filter, which suppresses the low-frequency components transmitted from the cathode leads 73 and 74. However, the high-frequency components are shielded by the filter case 83 and its cover 84. In addition, in the cooling mechanism 77 provided on the outer periphery of the anode cylinder 53, a cooling water passage 77a for passing cold water is arranged around the inside, and the heat accompanying the operation of the magnetron 100 is diffused by the cold water passing through.

[0039] The exhaust pipe 80 is used to exhaust the gas inside the vacuum tube 59 main body of the magnetron enclosing the cathode portion 78, the anode portion 79, and a part of the output portion 69. After the gas is evacuated to form a vacuum state, the front end of the exhaust pipe 80 is closed.

[0040] The first problem of coil damage and the second problem of suppressing the influence of unnecessary radiation on the fundamental wave in the high-output magnetron 100 described above are solved as follows.

[0041] (About the first topic)

[0042] The first problem is solved as follows.

[0043] Figure 2A This is a diagram showing the arrangement of the plate-like blade 52 when there are three through holes 52h. Figure 2B This is a diagram showing the arrangement of the plate-like blade 52 when there are four through holes 52h. Figure 2A , Figure 2B A diagram showing the through hole 52h provided in the plate-like blade 52. In order to solve the problem of coil burnout caused by the fundamental wave, the voltage equalizing ring is provided in a structure in which a through hole is provided at the end of the plate-like blade 52 to penetrate the voltage equalizing ring 64 instead of providing a notch on the side of the plate-like blade 52. Microwaves are suppressed from being transmitted to the choke coil 81 side at the lower part of the vacuum tube 59 body. In addition, the vacuum tube 59 body is a part in which the cathode part 78, the anode part 79 and a part of the output part 69 are sealed inside.

[0044] The plate-like blade 52 has the same number of through holes 52h arranged vertically near the end in the central axis direction. Figure 5 This will be described later.

[0045] In the present embodiment, when the through hole 52hn is used, n is set to a numerical value indicating an odd number starting with 1, and n gradually increases to 1, 3, 5, .... Also, the n+1th is 2, 4, 6, ..., which is a numerical value indicating an even number.

[0046] For example, in Figure 2A In the case where there are three through holes shown, when n=1, it becomes through hole 52h1 (first) and through hole 52h2 (second), and when n=3, it becomes through hole 52h3 (third).

[0047] exist Figure 2B When there are four through holes, they are through hole 52h1 (first) and through hole 52h2 (second) when n = 1, and through hole 52h3 (third) and through hole 52h4 (fourth) when n = 3. The arrangement of the through holes is not limited to this.

[0048] Figure 3A This is a diagram showing another arrangement in which the plate-like blade 52 has three through holes. Figure 3B FIG. 2 is a diagram showing another configuration in which the plate-like blade has four through holes. Figure 3A , Figure 3B As shown, the center points of the through holes do not necessarily need to be arranged on the same vertical line, and can also be arranged at positions offset relative to the central axis direction, or two rows can be arranged relative to the vertical line direction. However, it is preferred to align the through holes in the vertical line direction in terms of processing. Figure 3A as well as Figure 3B Figure 2 and Figure 2B In contrast, this is effective when there is a limit in the height direction of the plate-like blade 52 .

[0049] Figure 4 1 is a diagram showing the arrangement of the plate-like blades 52 on the anode cylinder 53. The plate-like blades 52 are radially arranged around the central axis of the magnetron in a manner such that one end is fixed to the inner wall surface of the anode cylinder 53 and the other end extends toward the central axis of the magnetron. These multiple plate-like blades 52 constitute a first plate-like blade group 52g1 (1 in the figure) consisting of a collection of plate-like blades in every other row in a clockwise or counterclockwise direction, with the plate-like blades at a predetermined position as the starting position, and a second plate-like blade group 52g2 (2 in the figure) consisting of a collection of plate-like blades other than the first plate-like blade group 52g1.

[0050] Figure 552h and the pressure equalizing ring 64. Figure 5 In order to facilitate the explanation, the Figure 4 Individual plate-like blades 52 are shown.

[0051] In this embodiment, at least three or more through holes 52h of the same number are arranged vertically near the end in the direction of the central axis on each plate-like blade 52. In order to pass one pressure equalizing ring 64 through the first through hole 52h1, one through the second through hole 52h2, and one through the third through hole 52h3, three or more pressure equalizing rings 64 must be provided. In addition, in this figure, an example of providing three through holes 52h and three pressure equalizing rings 64 in a minimum structure is used for explanation.

[0052] All the plate-like blades 52 belonging to the first plate-like blade group 52g1 have through holes of two shapes, and the through holes in the same order have the same shape. In addition, all the plate-like blades belonging to the second plate-like blade group 52g2 also have through holes of two shapes, and the through holes in the same order have the same shape.

[0053] Furthermore, in all the plate-like blades 52 belonging to the first plate-like blade group, the first and third through holes have different areas from the second through hole. Similarly, in all the plate-like blades belonging to the second plate-like blade group, the first and third through holes have different areas from the second through hole.

[0054] Specifically, if Figure 5 As shown, regarding the size of the first through hole 52h1 of the first plate-like blade group 52g1 and the second plate-like blade group 52g2, when the first through hole of the plate-like blade belonging to the first plate-like blade group 52g1 starts from a through hole with a small diameter, a through hole with a large diameter is arranged in the first through hole of the plate-like blade belonging to the next second plate-like blade group 52g2, and a through hole with a small diameter is arranged in the first through hole of the plate-like blade belonging to the next first plate-like blade group 52g1, and this action is repeated alternately.

[0055] Similarly, regarding the size of the second through holes of the first plate-like blade group 52g1 and the second plate-like blade group 52g2, when the second through holes of the plate-like blades belonging to the first plate-like blade group start from a through hole with a larger diameter, a through hole with a smaller diameter is provided in the second through holes of the plate-like blades belonging to the next second plate-like blade group 52g2, and a through hole with a larger diameter is provided in the second through holes of the plate-like blades belonging to the next first plate-like blade group 52g1, and this action is repeated alternately.

[0056] The third through hole is also the same as the first through hole. Each pressure equalizing ring 64 contacts the plate-like blade in a through hole with a small area, and does not contact the plate-like blade in a through hole with a large area. In addition, in the present invention, the shape of the through hole is described as a circle, but it does not need to be particularly set to a circle.

[0057] (About the second topic)

[0058] In this embodiment, the second problem, that is, the suppression of the influence of the unnecessary radiation on the fundamental wave, is solved by using three or more voltage grading rings 64. Figure 6 The reason for using three or more pressure equalizing rings 64 will be described.

[0059] Figure 6 : is a graph showing the correlation between the banding rate and the unnecessary radiation. The purpose of the voltage equalizing ring 64 is to equalize the potential of the plate-like blades 52 and to suppress the influence of the unnecessary radiation that becomes noise. Figure 6 Figure 6A shows the plate-like blade arrangement, and the enlarged view of the B portion of the plate-like blade arrangement 6A. Figure 6 B. The relationship between the band rate 6C. An example of a spectrum 6D.

[0060] The inventors have confirmed that in the high-power magnetron 100, the influence of unnecessary radiation cannot be sufficiently suppressed in a configuration with two voltage-equalizing rings 64. Therefore, in the present embodiment, the configuration is such that three or more voltage-equalizing rings are provided.

[0061] Specifically, the magnetron 100 resonates in the resonance cavity formed by the inner wall surface of the anode cylinder 53 and each plate-like blade 52, generating a fundamental wave having a resonance frequency. However, at this time, unnecessary radiation that adversely affects the fundamental wave is also generated. When the unnecessary radiation is close to the oscillation frequency of the fundamental wave, the influence of the unnecessary radiation on the fundamental wave may not be suppressed, causing abnormal oscillation and the magnetron stopping oscillation.

[0062] Specifically, if it is a household magnetron or a low-output magnetron with an output of about 2kW among industrial magnetrons with an output of 2 to 10kW, even if useless radiation is generated, the output is not large, so the possibility of causing abnormal oscillation is quite low. However, in a high-output magnetron of, for example, the 15kW class, the influence of useless radiation cannot be ignored.

[0063] In order to suppress unnecessary radiation, it is necessary to separate the unnecessary radiation in the frequency band close to the oscillation frequency of the fundamental wave from the oscillation frequency of the fundamental wave as much as possible to reduce the influence.

[0064] It is known that increasing the band rate will be effective in dissociating the unwanted radiation. Figure 6 The calculation formula for the banding ratio shown in the figure is obtained by increasing Figure 6The capacitance Cs formed by the gap between the grading ring and the blades not in contact with the grading ring shown in the enlarged view of part B of FIG. 1 can increase the band rate. In other words, the influence of the useless radiation on the fundamental wave can be eliminated.

[0065] In order to suppress the influence of the useless radiation on the fundamental wave, the inventors use at least three equalizing rings 64 to increase the Cs component in a high-output magnetron with an output of more than 15 kW. During the manufacturing stage of the magnetron, a test operation is carried out to set the number of through holes and equalizing rings to expand the dissociation between the oscillation frequency of the fundamental wave and the useless radiation, so that the useless radiation does not affect the fundamental wave.

[0066] Figure 7 : is a diagram showing the effect of three equalizing rings 64. In order to confirm the effect of this embodiment, the inventors used a structure with two equalizing rings 64 and a structure with three equalizing rings 64 to verify the generation of unwanted radiation. Figure 7 In the figure, the result of the structure with two pressure equalizing rings 64 is R72, and the result of the structure with three pressure equalizing rings 64 is R73.

[0067] In the case of result R72, the fundamental wave is 2.46 GHz, the unwanted radiation is 3.16 GHz, and the frequency difference from the fundamental wave is 0.7 GHz. In contrast, in the case of result R73, the fundamental wave is 2.38 GHz, the unwanted radiation is 3.23 GHz, and the frequency difference from the fundamental wave is 0.85 GHz. In the case of result R73, compared with result R72, by making the unwanted radiation of the frequency close to the oscillation frequency of the fundamental wave as far away from the fundamental wave as possible, it is possible to suppress the influence on communication equipment and the like using the fundamental frequency.

[0068] like Figure 7 As shown in the effect diagram of three equalizing rings, in the specification of two equalizing rings, large amplitude unnecessary radiation is generated near 3.2GHz, and the magnetron stops oscillating. When it is set to a structure with three equalizing rings, the unnecessary radiation near 3.2GHz is greatly reduced, and the influence on the fundamental wave is suppressed.

[0069] Figure 8 This is a diagram showing how to connect the pressure equalizing rings. Figure 8 The figure showing the connection of the equalizing rings is used to explain the connection of the equalizing rings. By improving the uniformity of the potentials of the nth equalizing rings and the uniformity of the potentials of the n+1th equalizing rings, the effect can be further improved on the basis of suppressing the generation of abnormal oscillation. Figure 8 As shown, it is preferred that the nth pressure equalizing rings are connected to each other at predetermined positions of the pressure equalizing rings, and the n+1th pressure equalizing rings are connected to each other at predetermined positions of the pressure equalizing rings.

[0070] As described above, the magnetron 100 of the present embodiment has the following features.

[0071] (1) The magnetron 100 is a high-output industrial magnetron, comprising: an anode cylinder 53; a plurality of plate-like blades 52, each having one end fixed to a plurality of different fixing portions 52f on the inner wall surface of the anode cylinder 53, and each having the other end extending from the fixing portion 52f toward the central axis of the magnetron; and a predetermined number of equalizing rings 64, which are arranged on the inner side of the anode cylinder 53, the plurality of plate-like blades 52 constitute a first plate-like blade group 52g1 consisting of a collection of plate-like blades in every other row clockwise or counterclockwise starting from a plate-like blade at a predetermined position, and a second plate-like blade group 52g2 consisting of a collection of plate-like blades other than the first plate-like blade group 52g1.

[0072] All the plate-like blades 52 belonging to the first plate-like blade group 52g1 and all the plate-like blades 52 belonging to the second plate-like blade group 52g2 have at least three or more through holes 52h of the same number near the front end in the direction of the central axis, and n is used as a numerical value representing an odd number starting with 1, and the nth equalizing ring 64_n is penetrated in a manner of contacting the nth through hole 52hn of all the plate-like blades belonging to the first plate-like blade group 52g1, and the n+1th equalizing ring 64_n+1 is penetrated in a manner of contacting the n+1th through hole 52gn+1 of all the plate-like blades belonging to the second plate-like blade group 52g2. Thus, damage to the choke coil 81 can be prevented, and oscillation stop caused by the generation of abnormal oscillation can be suppressed.

[0073] (2) In the magnetron 100 of (1), the nth through holes 52hn of all the plate-like blades belonging to the first plate-like blade group 52g1 have the same shape, the n+1th through holes 52hn+1 of all the plate-like blades belonging to the second plate-like blade group 52g2 have the same shape, and the nth through hole 52hn and the n+1th through hole 52hn+1 have different areas (see Figure 4 , Figure 5 ).

[0074] (3) In the magnetron 100 of (1), the nth equalizing ring 64_n does not contact the nth through hole 52hn of all the plate-like blades belonging to the second plate-like blade group 52g2, and the n+1th equalizing ring 64_n+1 does not contact the n+1th through hole 52hn+1 of all the plate-like blades belonging to the first plate-like blade group 52g1 (see Figure 5 ).

[0075] (4) In the magnetron of (1), it is characterized in that the nth voltage equalizing rings 64_n are connected to each other at the predetermined position of the voltage equalizing ring, and the n+1th voltage equalizing rings 64_n+1 are connected to each other at the predetermined position of the voltage equalizing ring (refer to Figure 8 ).

[0076] (5) In the magnetron 100 of (1), a test operation is carried out during the manufacturing stage of the magnetron to set the number of through holes 52h and equalizing rings 64 so as to increase the separation of the fundamental wave generated by resonance in the resonant cavity and the useless radiation (see Figure 7 ). As mentioned above, in Figure 7 In the case of two equalizing rings, large amplitude unwanted radiation is generated near 3.2 GHz, and the magnetron stops oscillating. When three equalizing rings are used, the unwanted radiation near 3.2 GHz is greatly reduced, indicating that the influence on the fundamental wave is suppressed.

[0077] In addition, the present invention is not limited to the above-described embodiments, and includes various modified examples. In addition, the above-described embodiments are embodiments described in detail to easily explain the present invention, and are not necessarily limited to having all the structures described. In addition, with respect to a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

Claims

1. A magnetron, a high-output industrial magnetron, characterized in that: have: Anode cylinder; a plurality of plate-like blades, each having one end fixed to a plurality of different fixing portions on the inner wall surface of the anode cylinder, and each having the other end extending from the fixing portion toward the central axis of the magnetron; and A predetermined number of pressure equalizing rings are arranged on the inner side of the anode cylinder, The plurality of plate-like blades constitute a first plate-like blade group consisting of a set of the plate-like blades in every other row in a clockwise or counterclockwise direction starting from a plate-like blade at a predetermined position, and a second plate-like blade group consisting of a set of the plate-like blades other than the first plate-like blade group. All the plate-like blades belonging to the first plate-like blade group and all the plate-like blades belonging to the second plate-like blade group have at least three or more through holes of the same number, which are set in a manner to increase the separation of the fundamental wave resonated in the resonance cavity and the unnecessary radiation, near the front end in the direction of the central axis during the test operation in the manufacturing stage of the magnetron. n is set to a numerical value representing an odd number starting with 1, and the nth pressure equalizing ring is penetrated in a manner of contacting the nth through-holes of all the plate-like blades belonging to the first plate-like blade group, The n+1th pressure equalizing ring is penetrated so as to contact the n+1th through-holes of all the plate-like blades belonging to the second plate-like blade group.

2. The magnetron according to claim 1, characterized in that: The n-th through holes of all the plate-like blades belonging to the first plate-like blade group have the same shape, The n+1th through holes of all the plate-like blades belonging to the second plate-like blade group have the same shape. The nth through hole and the (n+1)th through hole have different areas.

3. The magnetron according to claim 1, characterized in that: The nth pressure equalizing ring does not contact the nth through hole of all the plate-like blades belonging to the second plate-like blade group, The n+1th pressure equalizing ring does not contact the n+1th through hole of all the plate-like blades belonging to the first plate-like blade group.

4. The magnetron according to claim 1, characterized in that: The nth pressure equalizing rings are connected to each other at predetermined positions of the pressure equalizing rings, The n+1th pressure equalizing rings are connected to each other at predetermined positions of the pressure equalizing rings.

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