JP2005209426A - Magnetron - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small magnetron capable of providing high cooling capacity. <P>SOLUTION: By closely disposing a cooling block 45 having two systems such as upper-tier side passage 45U (ducts 45a, 45b and 45c) for running a cooling medium in the axis direction of an anode cylinder 3 in its inside and a lower-tier side passage 45L (ducts 45a', 45b' and 45c') on a nearly whole surface of the circumferential wall of the anode cylinder 3, surface areas in the upper-tier side passage 45U and the lower-tier side passage 45U are increased, whereby a surface area in contact with the cooling medium is increased and a heat radiation surface area is increased, so that high cooling capacity can be provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a magnetron that generates microwaves, and more particularly to a magnetron that includes a cooling block that directly cools by circulating a cooling medium around an outer periphery of an anode cylinder.

  In general, a magnetron is widely used in fields such as a radar device, a medical device, a cooking device such as a microwave oven, a semiconductor manufacturing device, or other microwave application devices because it can efficiently generate a high-frequency output.

  High-power microwaves are required for semiconductor devices and industrial heating. In this case, it is necessary to improve the cooling performance of the magnetron in accordance with the microwave output, and it is necessary to increase the size of the cooling structure. However, an increase in the size of the cooling structure leads to an increase in the size of the magnetron, leading to an increase in the storage space of the magnetron and an increase in the size of the apparatus itself. Therefore, a magnetron having a cooling structure with a small size and excellent performance is required.

  As a solution to such a problem, as shown in the cross-sectional view of the main part in FIG. 6, the anode cylinder 3 as the anode part is provided with a pair of annular permanent magnets 4a and 4b at the upper and lower ends. The permanent magnets 4a and 4b are sandwiched and held and fixed by a yoke 6 forming a magnetic circuit, and a tube having an inlet 45a for supplying a cooling medium and an outlet 45b 'for discharging a cooling medium to the outer peripheral wall of the anode cylinder 3. A cooling block 45 having a path formed is attached in close contact with the entire surface by mounting screws 46, and is disposed in thermal contact with the permanent magnets 4a and 4b and a part of the yoke 6, whereby the anode cylinder 3 and the permanent magnet. The size of the magnetic circuit is reduced by directly cooling the 4a, 4b and the yoke 6 with a cooling medium. Reference numeral 13 denotes a microwave antenna, 34 denotes a filter case, and 35 denotes a cathode heating lead.

  As another means for solving such a problem, a cooling pipe 36 is wound around the outer peripheral wall of the anode cylinder 3 and brazed as shown in a cross-sectional view of the main part in FIG. By circulating the medium, the anode cylinder 3 is directly cooled to reduce the size of the magnetic circuit. In addition, regarding this type of prior art, for example, Patent Literature 1 and Patent Literature 2 listed below can be cited.

Japanese Patent Laid-Open No. 5-54805 JP-A-8-222410

  In general, a magnetron having a cooling structure configured as described above is used to increase the flow rate of the cooling medium in order to obtain a sufficient cooling effect. However, even if the cooling block 45 made of Al or Cu having high thermal conductivity is in close contact with the anode cylinder 3, if the cooling medium exceeds a certain flow rate, the thermal conductivity from the anode cylinder 3 to the cooling medium becomes a limit, and cooling is performed. There is a problem that the cooling performance is not improved even if the flow rate of the medium is increased.

  Further, in the cooling structure in which the anode cylinder 3 and the cooling pipe 36 are brazed, the magnetron body is exposed to a high temperature after exhausting. As a result, there is a problem that the reliability of the vacuum tube is lowered. In addition, since a large amount of wax material and heat are used, there is a problem that environmental problems occur.

  Accordingly, the present invention has been made to solve the above-described conventional problems, and an object of the present invention is to provide a magnetron that is small in size and has a high cooling capacity.

  Another object of the present invention is to provide a magnetron that is compact and can provide high output.

  In order to achieve such an object, the magnetron according to the present invention has a cathode part having a thermoelectron source installed at the center of a tube axis, and one end separated from the cathode part with the cathode part at the center. A plurality of anode vanes arranged radially and parallel to the tube axis and the other end of the anode vane to form a plurality of resonance cavities, and a resonance cavity from the tube axis direction. A pair of magnetic poles made of a ferromagnetic material that forms an internal magnetic path passing through the working space provided at the sandwiched position, and a ferromagnet that seals the anode cylinder at both ends in the tube axis direction and opposite to the magnetic resonance cavity A pair of sealing metal composed of a body, a pair of annular permanent magnets coaxial with the magnetic pole and disposed on the opposite side of the sealing metal with respect to the magnetic pole, and on the side opposite to the magnetic pole with respect to the permanent magnet Ferromagnet that forms the external magnetic path of a permanent magnet with the magnetic pole And a plurality of cooling medium flow paths along the tube axis direction of the anode cylinder and disposed in contact with a part of the yoke. By providing a cooling block and a pipe joint connected to one of the open ends of the upper flow paths and one of the open ends of the lower flow paths, the surface area in the flow paths is increased. As a result, the surface area of contact with the cooling medium is increased, and the surface area of heat dissipation is increased, thereby solving the problems of the background art.

  In the above configuration, the cooling block has a distance A from the tube axis of the anode cylinder to the yoke, a distance B from the tube axis of the anode cylinder to the center of the cooling pipe, and a radius of the anode cylinder C. , 29.0−3.0 ≦ A−C ≦ 29.0 + 3.0, the surface area of contact with the cooling medium in the flow path is expanded, and the current constituent members are used for the background art. The problem can be solved.

  Moreover, in the said structure, since a cooling block has high heat conductivity by comprising from an aluminum material, a high cooling capability is obtained and the subject of background art can be solved.

  Moreover, in the said structure, since a cooling block has high thermal conductivity by comprising from a copper material, a high cooling capability is obtained and the subject of background art can be solved.

  The present invention is not limited to the configurations described in the above-described configurations and the embodiments described later, and it goes without saying that various modifications can be made without departing from the technical idea of the present invention. .

  According to the present invention, since the cooling block is small and high cooling performance is obtained, an extremely excellent effect that a compact and high output magnetron can be realized is obtained.

  In addition, since a high cooling performance can be obtained, an extremely excellent effect that a magnetron having high quality and reliability can be realized can be obtained.

  Furthermore, in manufacturing, it is possible to obtain an extremely excellent effect that a compact and high output magnetron with high workability can be realized.

  Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings of the examples.

  FIG. 1 is a cross-sectional view of an essential part for explaining an outline of a configuration according to a first embodiment of a magnetron according to the present invention. In FIG. 1, a plurality of anode vanes 2 are fixed to the anode cylinder 3 by brazing or the like around the cathode filament 1 spirally formed as a heat emission source, or an extrusion molding method together with the anode cylinder 3. Are formed integrally to form a part of the anode part.

  The anode portion is centered on the cathode filament 1 and one end thereof is separated from the cathode filament 1 to form a working space, and a plurality of anode vanes arranged radially and parallel to the tube axis, and the anode vane A plurality of radial resonant cavities are formed by the anode cylinder 3 coupled to the other end.

  A pair of annular permanent magnets 4a and 4b are disposed on the upper and lower ends of the anode cylinder 3 via a pair of magnetic poles 5a and 5b made of a ferromagnetic material such as soft iron, respectively. In the figure, reference numeral 6 denotes a yoke, and 7 denotes an antenna lead. The antenna lead 7 is electrically cut and sealed with the anode vane 2 at one end and the exhaust pipe 8 at the other end. Reference numeral 9 denotes a choke portion, 10 an antenna cover, 11 a cylindrical insulator, and 12 an exhaust pipe support. The antenna lead 7 and the exhaust pipe support 12 constitute a magnetron antenna 13.

  21 is an upper end shield, 22 is a lower end shield, 23 and 24 are cathode leads (23 is a center lead, 24 is a side lead), 25 is an input side ceramic, 26 is a cathode terminal, and 27 is a spacer. The spacer 27 has a function of preventing disconnection of the cathode filament 1 and is arranged at a predetermined position by a sleeve 28 to constitute a cathode portion.

  The choke coil 31 is connected to one end of a feedthrough capacitor 32, and this feedthrough capacitor 32 is attached to a filter case 33 of the input section. The other end of the feedthrough capacitor 32 is connected to a power source. Further, the bottom of the filter case 33 is closed with a lid 34 at a high frequency. 41 and 42 are cap-shaped upper and lower end sealing metals, 43 is a metal gasket, and is electrically connected to the upper yoke 44.

  Further, the outer peripheral wall of the anode cylinder 3 is made of an Al (aluminum) material having high thermal conductivity and workability, and has an upper-stage flow path 45U and a lower-stage flow path 45L through which a cooling medium is circulated and circulated. A cooling block 45 formed along the tube axis direction of the anode cylinder 3 is disposed in close contact with the outer peripheral wall thereof, and is in close contact with the yoke 6 by a plurality of mounting screws 46 to be held and fixed. A contact surface between the inner peripheral wall of the opening (not shown) of the cooling block 45 and the outer peripheral wall of the anode cylinder 3 is disposed in contact with the thermal diffusion compound by applying and adhering it. The cooling block 45 may be formed of a Cu (copper) material instead of the Al material.

  2A and 2B are diagrams for explaining the configuration of the cooling block 45. FIG. 2A is a plan view seen from above, and FIG. 2B is a plan view seen from the direction of arrow B in FIG. FIG. 2C shows a plan view seen from the direction of arrow C in FIG. As shown in FIG. 2, the cooling block 45 includes an opening 45d having a slightly larger inner diameter than the diameter of the anode cylinder 3, a mounting slit 45e at the center, and a cylindrical pipe 45a through which a cooling medium flows. , 45b, 45c are connected to form an upper-stage channel 45U.

  Similarly, on the lower stage side of the cooling block 45, as shown in FIG. 2B, there is a lower stage side passage 45L formed by connecting cylindrical pipes 45a ', 45b', 45'c having the same structure. Is formed. In the drawing, the flow paths formed on the upper stage side and the lower stage side of the cooling block 45 in two stages are indicated by reference numerals 45a, 45b, and 45c in the upper stage pipe lines and reference numerals 45a 'and 45b' in the lower stage pipe lines. , 45c ′. That is, it has a structure in which two systems of flow paths, that is, the upper flow path 45U and the lower flow path 45L are formed.

  Further, the pipes 45a, 45b, 45c constituting the upper flow path 45U of the cooling block 45 and the pipes 45a ′, 45b ′, 45c ′ constituting the lower flow path 45L are provided on the main body of the cooling block 45, respectively. An opening is excavated from the side surface in the surface direction, for example, with a drill or the like, and the pipes 45a, 45b, 45c cross each other and communicate with each other to form a substantially U-shaped channel. Similarly, the lower pipes 45a ', 45b', and 45c 'are also communicated so that the apertures intersect each other to form a substantially U-shaped flow path. Further, the opening S of each of these pipes 45a, 45b, 45c, 45a ', 45b', 45c 'is threaded at the inner peripheral edge thereof, and various members described later can be connected by screwing. It has a screw structure.

  Further, an inlet S for supplying a cooling medium is provided to the opening S of the pipe 45a formed in the cooling block 45, and an outlet, a pipe 45a 'and a pipe 45b are provided to the opening S of the pipe 45a'. The opening S has a function as a connection port for connecting a pipe joint described later. In addition, these functions may be reversed. Further, the opening S of the pipe 45c and the pipe 45c ′ has a function as an embedding hole of a sealing screw that suppresses leakage of the cooling medium.

  In FIG. 2, reference numerals 47 a, 47 b, 47 c, and 47 d are mounting screw holes for fixing the cooling block 45 in contact with the side wall of the yoke 46. Although not shown on the lower side of the cooling block 45, mounting screw holes 47a ', 47b', 47c ', 47d' having the same configuration are formed. Reference numerals 48a, 48b, and 48c denote insertion holes for mounting screws that fasten and fix the cooling block 45 to the anode cylinder 3.

  The cooling block 45 configured in this manner has an opening 45d attached to the outer peripheral wall of the anode cylinder 3 as shown in a plan view seen from the side in FIG. 3, and screws are attached to the mounting screw insertion holes 48a, 48b, 48c. 49a and nut 49b are used to fasten and fix, and are in close contact with the outer peripheral wall of anode cylinder 3. In this case, the heat diffusion compound is applied and brought into close contact with the contact surface between the inner peripheral wall of the opening 45 d of the cooling block 45 and the outer peripheral wall of the anode cylinder 3.

  Further, as shown in a plan view seen from the side in FIG. 4, the opening S of the pipe 45a ′ of the lower flow path 45L of the cooling block 45 and the opening S of the pipe 45b of the upper flow path 45U A pipe joint 50 having threaded portions at both ends is connected by screwing, and a supply pipe 51 for injecting a cooling medium is similarly connected by screwing to the inlet of the pipe 45a, and the pipe 45b 'is discharged. The outlet pipe 52 is similarly connected to the outlet by screwing. Further, although not shown in the drawings, plugs 45c and 45 ′ (FIG. 2) are embedded in the openings S of the pipelines 45c and 45c ′ through plugs or the like that are embedded in the openings S to prevent leakage of the cooling medium. See) is sealed.

  In such a configuration, when the cooling medium is supplied from the supply pipe 51 connected to the pipe line 45a of the upper stage side flow path 45U, the cooling block flows through the flow path 45U (pipe lines 45a, 45b, 45c). The upper side of 45 is cooled, and the cooling medium in the flow path 45U passes through the pipe joint 50 and flows through the lower flow path 45L (pipe lines 45a ′, 45b ′, 45c ′) to form a cooling block. The lower side of 45 is cooled. The cooling medium flowing through the flow path 45L is circulated to the external heat converter through the discharge pipe 52, re-cooled, and supplied to the supply pipe 51.

  In such a configuration, as shown in a side view in FIG. 3, the distance from the tube axis of the anode cylinder 3 to the yoke (see FIG. 1) is A, and the distance from the tube axis of the anode cylinder 3 to the center of the flow path is B. The radius of the anode cylinder 3 is C, the height of the anode cylinder 3 is H1, the pitch of the cooling medium pipe is H2, the height of the cooling block 45 is H4, and the pipe diameter is R. When the relationship between the anode cylinder 3 and the cooling block 45 is set in the range of 29.0−3.0 ≦ A−C ≦ 29.0 + 3.0, the surface area with the cooling medium in the flow paths 45U and 45L. This increases the heat dissipation area, thereby improving the cooling efficiency. As a result, it is possible to realize a compact and high-power magnetron with high workability in manufacturing using the existing components such as the permanent magnet, the anode cylinder, and the yoke.

  In such a configuration, when the diameter R of the flow path 45U (the pipe paths 45a to 45c) and the flow path 45L (the pipe paths 45a ′ to 45c ′) is increased, the cooling block 45 increases the pipe surface area. The distance B from the tube axis of the anode cylinder 3 to the centers of the flow paths 45U and 45L is increased, resulting in an adverse effect of increasing the volume of the cooling block 45. Therefore, in order to increase the surface area in the flow paths 45U and 45L, a plurality of pipelines are provided. However, in consideration of practicality, it is necessary to suppress the flow resistance of the cooling medium as much as possible and to secure a space for mounting the pipe joint 50. Therefore, the flow path diameter R is 15 mm to 8 mm (pipe parts: 3/8 inch). (Equivalent to ˜1 / 8 inch) is preferable.

  Further, in such a configuration, a pair of upper and lower end sealing metals 41 and 42 are brazed or welded to both end portions of the anode cylinder 3, and a vacuum sealing portion whose surface is an uneven portion is formed in this welded portion. . Therefore, in order to avoid this welded portion, the height H4 of the cooling block 45 is formed to be smaller than the height H1 of the anode cylinder 3, so that the outer peripheral surface of the anode cylinder 3 and the inner peripheral surface of the cooling block opening 45d. The tight contact area can be ensured to the maximum.

  Further, in such a configuration, the cooling block 45 is fixed to the yoke 6 by making a surface contact with the plurality of screws 46, so that the anode cylinder 3 is broken and the tube is damaged in the demagnetization of the pair of permanent magnets 4a and 4b. Generation of shaft misalignment and the like can be reliably prevented. Further, the surface contact between the cooling block 45 and the yoke 6 can suppress the temperature rise of the exterior members such as the filter case 33 and the upper yoke 44. Furthermore, since the upper yoke 44 and the permanent magnet 4a and the lower yoke 6 and the permanent magnet 4b are in surface contact with each other and cooled indirectly, stable electrical characteristics can be secured.

  Further, in such a configuration, the cooling block 45 can be easily manufactured, attached, and inspected by using the current manufacturing equipment, so that it is possible to secure reliability against leakage of the cooling medium.

  According to such a configuration, the upper stage flow path 45U (pipe lines 45a, 45b, 45c), the pipe joint 50, and the lower stage flow path 45L (pipe lines 45a ′, 45b ′, 45c ′) have two paths. By circulating the cooling medium, a long cooling medium circulation path is formed, the heat radiation surface area is enlarged, and the cooling block 45 is entirely cooled to obtain a high cooling capacity. While being suppressed, the temperature rise of the exterior member which contacts the cooling block 45 is also suppressed simultaneously. Accordingly, since the overall temperature rise of the magnetron is suppressed, a compact and high output magnetron can be realized using the current components.

  In addition, according to such a configuration, since the heat radiation surface area is increased and a high cooling capacity is obtained, the drift characteristics of the magnetron can be improved, and the reliability such as a long life can be improved at the same time. . Furthermore, since a high cooling capacity is obtained, it can be applied to a magnetron using a permanent magnet that is easily demagnetized at a high temperature.

  5 (a) to 5 (d) show the inside of the upper channel 45U in a state where the openings S of the upper tube 45c and the lower tube 45c 'described with reference to FIG. And a modified example of the flow path for sending and discharging the cooling medium into and from the lower stage flow path 45L. In the figure, a black arrow indicates a cooling medium feeding direction, a white arrow indicates a cooling medium discharge direction, and a normal arrow indicates a cooling medium flow direction. FIGS. 5 (a) and 5 (b) show a distribution method in which the upper stage side and the lower stage side are circulated in parallel. In such a parallel connection, since there are two distribution paths, the heat radiation area is increased and the cooling efficiency is increased. In addition, a large amount of cooling medium can be supplied by two systems.

  5 (c) and 5 (d) show a distribution method in which the upper stage side and the lower stage side are distributed in series. In such series connection, the distribution path length is doubled, so that the heat radiation area increases. In addition, the cooling capacity can be improved. In any distribution method, a high cooling capacity can be obtained as described above. Needless to say, the pipe joint 50 is used when the series connection of the upper-stage flow path 45U and the lower-stage flow path 45L is employed.

  In the serial connection as shown in FIGS. 5C and 5D, the flow rate in the flow path is increased even with a small cooling medium flow rate, and the cooling effect can be increased. On the other hand, in the parallel connection shown in FIGS. 5A and 5B, the flow path is short, so that the pressure of the cooling medium is hardly reduced. Therefore, it is suitable for a large amount of coolant flow. That is, by selecting the structure shown in FIGS. 5A to 5D, it is possible to deal with a wide range from a small flow rate to a large flow rate.

  In the above-described embodiment, the case where the cooling block 45 is provided with the two channels 45U and 45L divided into the upper side and the lower side has been described, but the present invention is limited to this. It is needless to say that the same effect as described above can be obtained even if three or four channels are provided by forming the channel diameter as small as a usable limit value.

It is principal part sectional drawing which shows the structure by the Example of the magnetron by this invention. It is a top view which shows the structure of the cooling block of FIG. It is the top view seen from the side surface which shows the relationship between the anode cylinder of FIG. 1, and a cooling block. It is the top view seen from the side which shows the completion state of the magnetron of FIG. It is a figure explaining the modification of the sending in and discharge method of the cooling medium to a cooling block. It is the top view seen from the side which shows the structure of the present magnetron. It is the top view seen from the side which shows the structure of the present magnetron.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cathode filament, 2 ... Anode vane, 3 ... Anode cylinder, 4a ... Permanent magnet, 4b ... Permanent magnet, 5a ... Magnetic pole, 5b ... Magnetic pole, 6 ...・ Yoke, 7 ... antenna lead, 8 ... exhaust pipe, 9 ... choke part, 10 ... antenna cover, 11 ... cylindrical insulator, 12 ... exhaust pipe support, ... Magnetron antenna, 21 ... upper end shield, 22 ... lower end shield, 23 ... cathode lead (center lead), 24 ... cathode lead (side lead), 25 ... input side ceramic , 26 ... cathode terminal, 27 ... spacer, 28 ... sleeve, 31 ... choke coil, 32 ... feedthrough capacitor, 33 ... filter case, 34 ... lid, 35 ... ..Cathode heating wires, 4 ... upper end sealing metal, 42 ... lower end sealing metal, 43 ... metal gasket, 44 ... upper yoke, 45 ... cooling block, 45U ... upper-stage flow path, 45L ... Lower flow path, 45a ... pipeline, 45b ... pipeline, 45c ... pipeline, 45d ... opening, 46e ... slit, 45a '... pipeline, 45b' ..Pipe, 45c '... Pipe, 46 ... Mounting screw, 47a ... Mounting screw hole, 47b ... Mounting screw hole, 47c ... Mounting screw hole, 47d ...・ Mounting screw hole, 48a... Mounting screw insertion hole, 48b... Mounting screw insertion hole, 48c... Mounting screw insertion hole, 49a... Screw, 49b. 50 ... Pipe fittings 51 ... Pipes for supply 52 ... For discharge Type, S ··· opening.

Claims (5)

A cathode part installed at the center of the tube axis and having a thermionic source;
Centering on the cathode part and separating one end from the cathode part to form a working space, connecting a plurality of anode vanes arranged radially and parallel to the tube axis and the other end of the anode vane, An anode cylinder forming a plurality of resonant cavities;
A pair of magnetic poles made of a ferromagnetic material provided at a position sandwiching the resonant cavity from the tube axis direction and forming an internal magnetic path through the working space;
A pair of sealing metals made of a ferromagnetic material that seals the anode cylinder at both ends of the magnetic pole in the tube axis direction and opposite to the resonance cavity of the magnetic pole;
A pair of annular permanent magnets coaxial with the magnetic pole and installed on the opposite side of the sealing metal with respect to the magnetic pole;
A yoke made of a ferromagnetic material that forms an external magnetic path of the permanent magnet together with the magnetic pole on the side opposite to the magnetic pole with respect to the permanent magnet;
A cooling block disposed in close contact with the outer peripheral wall of the anode cylinder, and having a plurality of cooling medium flow paths along the tube axis direction of the anode cylinder;
A magnetron characterized by comprising:   2. The magnetron according to claim 1, wherein one of the open ends of the upper-side pipes of the plurality of flow paths and one of the open ends of the lower-stage pipe lines are connected by a pipe joint. The cooling block has a distance from the tube axis of the anode cylinder to the yoke as A, a distance from the tube axis of the anode cylinder to the center of the cooling line as B, and a radius of the anode cylinder as C,
3. The magnetron according to claim 1, wherein a relationship of 29.0−3.0 ≦ A−C ≦ 29.0 + 3.0 is set.   The magnetron according to any one of claims 1 to 3, wherein the cooling block is made of a molded body of an aluminum material.   The magnetron according to any one of claims 1 to 3, wherein the cooling block is formed of a copper body.

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