MAGNETRON, AND DEVICE USING MICROWAVES

Abstract

 An anode cylinder and a permanent magnet are efficiently cooled, and a cooling member per se is prevented from being upsized while suppressing a variation of a cooling performance for the permanent magnet. A magnetron according to the present invention includes: an anode cylinder; permanent magnets disposed on both ends of the anode cylinder; a magnetic yoke which stores the anode cylinder and the permanent magnets therein; a cooling member which stores the anode cylinder therein and which has at least a part thereof fixed to the anode cylinder; and a connection portion arranged between the magnetic yoke and the cooling member.

Description

Technical Field

[0001] The present invention relates to a magnetron and a device using microwaves.

Background Art

[0002] A configuration of a liquid-cooled magnetron will be described with reference to FIGS. 6A and 6B. FIG. 6A is an overall configuration diagram of a magnetron 100 in a conventional example, and FIG. 6B is a perspective view of a cooling block 110. As illustrated in FIG. 6A, the magnetron 100 is equipped with the cooling block 110 that contacts an outer peripheral surface of an anode cylinder (not shown) within a yoke 106, and that internally includes a circulation conduit 112 which allows a medium for cooling the anode cylinder to flow therein. Also, the cooling block 110 thermally contacts permanent magnets 105 disposed on both ends of the anode cylinder in a long axis direction thereof, and a part of the yoke 106 (refer to Patent Document 1).

[0003] As illustrated in FIG. 6B, the cooling block 110 is made of a material having a cooling function, and an inlet port 112A and an output port 112B of the circulation conduit 112 are formed on one side surface thereof. The circulation conduit 112 extends from the inlet port 112A, is formed inside of the cooling block 110 in substantially a U-shaped configuration so as to surround the anode cylinder, and arrives at the output port 112B.

[0004] When the circulation conduit 112 is formed inside of the cooling block 110, a circulation conduit parallel to the one side surface of the cooling block 110 in which the inlet port 112A and the output port 112B of the circulation conduit 112 are formed by penetrating through the cooling block 110 and then stopping by a cap 112C in FIG. 6B.

Related Art Documents

Patent Documents

[0005] Patent Document 1: JP-A-5-054805

Summary of the Invention

Problem to be Solved by the Invention

[0006] In general, in an air-cooled magnetron, the permanent magnets are cooled directly by wind. On the other hand, in the liquid-cooled magnetron, because the permanent magnets are cooled indirectly through a magnetic yoke, the cooling effect is low. Further, during the operation of the magnetron, the permanent magnet is degaussed because of high temperature, and the magnetic flux density is decreased to drop an anode voltage. As a result, the output of the liquid-cooled magnetron is decreased.

[0007] Also, in the above-mentioned liquid-cooled magnetron 100, since most of the cooling block 110 contacts the anode cylinder, the anode cylinder that becomes at high temperature during the operation of the magnetron 100 is cooled by the medium flowing in the circulation conduit 112. However, a portion of the cooling block 110, which thermally contacts the permanent magnets 105, is extremely small as compared with the entire cooling block 110, and the cooling effect on the permanent magnets 105 cannot be expected.

[0008] Also, although the portion of the cooling block 110, which thermally contacts the permanent magnets 105, is small, the portion is integrated with a portion that contacts the anode cylinder. Therefore, the cooling block 110 per se is upsized.

[0009] Further, because the cooling block 110 is an integral block that covers the permanent magnets 105, a contact property of the inner side of the cooling block 110 with the permanent magnets 105 is degraded due to distortion of the outer diameter of the permanent magnets 105, and the radiation effect is low. Also, when the cooling block 110 and the permanent magnets 105 forcedly contacts each other during assembling, a trouble occurs in the oscillation characteristic of the magnetron 100 due to the deformation of the permanent magnets 105 or the anode cylinder.

[0010] Further, in the above-mentioned magnetron 100, in manufacturing the cooling block 110, for example, when the anode cylinder is positioned with respect to the anode cylinder, a gap is slightly formed between a portion of the cooling block 110 which contacts the permanent magnets 105 and the permanent magnets 105. For that reason, a cooling performance of the cooling block 110 with respect to the permanent magnets 105 is not kept constant, and varied.

[0011] An object of the present invention is to provide a magnetron configured so that a connection portion provided separately from a cooling member can contact a permanent magnet, whereby an anode cylinder and a permanent magnet can be efficiently cooled, and the cooling member per se can be prevented from being upsized while a variation of the cooling performance to the permanent magnet is suppressed.

Means for Solving the Problem

[0012] The present invention provides a magnetron including: an anode cylinder; permanent magnets disposed on both ends of the anode cylinder; a magnetic yoke which stores the anode cylinder and the permanent magnets therein; a cooling member which stores the anode cylinder therein and which has at least a part thereof fixed to the anode cylinder; and a connection portion arranged between the magnetic yoke and the cooling member.

[0013] In the magnetron described above, the connection portion allows the permanent magnet and the cooling member to contact each other.

[0014] In the magnetron described above, an inner surface of the connection portion contacts the permanent magnet, and a surface of the connection portion substantially perpendicular to the inner surface is fixed to the cooling member.

[0015] In the magnetron described above, the connection portion is made of any one of: copper and copper alloy; and aluminum and aluminum alloy.

[0016] In the magnetron described above, the connection portion includes a plurality of magnet contact pieces arranged along an outer peripheral surface of the permanent magnet having an annular shape, and each of the magnet contact pieces includes: a horizontal portion fixed to the cooling member; and an erect portion which has a surface continuous to the horizontal portion and which contacts the outer peripheral surface of the permanent magnet.

[0017] In the magnetron described above, the connection portion is arranged along an outer peripheral surface of the permanent magnet having an annular shape, and the connection portion includes: a plurality of horizontal portions fixed to the cooling member; and an erect portion which has a surface continuous to the plurality of horizontal portion and which contacts the outer peripheral surface of the permanent magnet.

[0018] In the magnetron described above, the connection portion is formed of a molded member made of an insulating resin having high thermal conductivity.

[0019] In the magnetron described above, a thermal conductive paste is coated between: the connection portion and the permanent magnet; and/or the connection portion and the cooling member.

[0020] The present invention provides a device using microwaves including the magnetron described above.

Advantages of the Invention

[0021] According to the magnetron and the device using microwaves, by a configuration in which a connection portion provided separately from a cooling member can contact a permanent magnet, an anode cylinder and a permanent magnet can be efficiently cooled, and the cooling member per se can be prevented from being upsized while a variation of the cooling performance to the permanent magnet is suppressed.

Brief Description of the Drawings

[0022] 

FIG. 1 is an overall configuration diagram of a magnetron 1 according to an embodiment of the present invention.

FIG. 2A is a plan view of a cooling block 20, and FIG. 2B is a side view of the cooling block 20.

FIG. 3A is a plan view of a cooling block 40, and FIG. 3B is a side view of the cooling block 40.

FIG. 4 is a perspective view of a magnet contact piece 41 B.

FIG. 5 is a perspective view of an annular magnet contact portion 61 B.

FIG. 6A is an overall configuration diagram of a magnetron 100 in a conventional example, and FIG. 6B is a perspective view of a cooling block 110.

Mode for Carrying Out the invention

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0024] FIG. 1 is an overall configuration diagram of a magnetron 1 according to an embodiment of the present invention. The magnetron 1 illustrated in FIG. 1 mainly includes a magnetic yoke 4, an output portion 9 disposed on an upper portion of the magnetic yoke 4, and a filter 11 disposed below the magnetic yoke 4. An anode cylinder 10, two annular permanent magnets 8A, 8B disposed on both ends of the anode cylinder 10, and a cooling block 20 that covers the surrounding of the anode cylinder 10 are accommodated within the magnetic yoke 4. A filter 11 includes a choke coil and a penetration capacitor 7.

[0025] The magnetic yoke 4 has one end opened and the other end closed, and includes a main body 4a, and a cover 4b that closes an opening end of the main body 4a. The two annular permanent magnets 8A, 8B, the anode cylinder 10, and the cooling block 20 that covers the surrounding of the anode cylinder 10 are accommodated within the magnetic yoke 4.

[0026] The anode cylinder 10 is held by the magnetic yoke 4 from the outsides of the annular permanent magnets 8A and 8B disposed on both of the upper and lower ends thereof. The annular permanent magnet 8B disposed on a lower side of the drawing is a magnet of the input side, and the annular permanent magnet 8A arranged on an upper side thereof is a magnet on an output side. Anode vanes are arranged radially within the anode cylinder 10, and cavity resonators are formed by spaces surrounded by the respective adjacent anode vanes and the anode cylinder 10. Also, an anode structure is arranged in the center of the anode cylinder 10, and the spaces surrounded by the anode structure and the anode vanes form active spaces.

[0027] When the magnetron 1 according to this embodiment is used, after an interior of the magnetron 1 is put into a vacuum state, a desired electric power is supplied to the anode structure to emit thermions, and a high DC voltage is applied between the anode vanes and the anode structure. A magnetic field is created in the active spaces in a direction orthogonal to a direction along which the anode structure and the anode cylinder 10 face each other by the annular permanent magnets 8A and 8B. When the high DC voltage is applied between the anode vanes and the anode structure, electrons emitted from the anode structure are pulled out toward the anode vanes. The electrons orbit while revolving due to the electric field and the magnetic field in the active spaces, and arrive at the anode vanes. In this situation, an energy associated with electron motion is supplied to the cavity resonators, and contributes to the oscillation of the magnetron.

[0028] The cooling block 20 includes a main body 21A that contacts the anode cylinder 10, and two magnet contact portions 21 B that are formed separately from the main body 21A, that contact the annular permanent magnets 8A and 8B, and that cool the annular permanent magnets 8A and 8B.

[0029] The two magnet contact portions 21 B are connection portions that each connect the main body 21A to the annular permanent magnet 8A or 8B when viewed from the main body 21A.

[0030] Also, the main body 21A contacts the anode cylinder 10, and mainly cools the anode cylinder 10. On the other hand, the two magnet contact portions 21 B are regarded as the connection portions when viewed from the main body 21A, but have a function of cooling the annular permanent magnets 8A and 8B. For that reason, the main body 21A and the two magnet contact portions 21 B configuring the cooling block 20 function as a cooling member.

[0031] Also, the cooling block 20 has a first fastening portion 22A in a part thereof, and is fixed to the anode cylinder 10 by fastening first screws 22B of the first fastening portion 22A after having been mounted on the anode cylinder 10. For that reason, an inner wall surface of the cooling block 20 contacts an outer wall surface of the anode cylinder 10. When the cooling block 20 is fixed to the anode cylinder 10, a slight gap is formed between the cooling block 20 and the magnetic yoke 4.

[0032] The cooling block 20 is made of a metal having a high thermal conductivity, and a cooled liquid circulation conduit 23 for circulating the cooled liquid is formed inside thereof. The cooled liquid flows into the cooled liquid circulation conduit 23. For that reason, the cooling block 20 can efficiently cool the anode cylinder 10 and the annular permanent magnets 8A, 8B, which contacts the cooling block 20. In the magnetron 1 according to this embodiment, the cooling block 20 is made of aluminum.

[0033] Subsequently, a configuration of the cooling block 20 will be described with reference to FIGS. 2A and 2B. FIG. 2A is a plan view of the cooling block 20 when viewed from above, and FIG. 2B is a side view of the cooling block 20.

[0034] The main body 21A internally includes a first container 24 that contains the anode cylinder 10 therein, and the cooled liquid circulation conduit 23. In FIG. 2A, as indicated by dashed lines, the cooled liquid circulation conduit 23 extends from an inlet port 23A, is formed inside of the main body 21A in a substantially U-shape so as to surround the anode cylinder 10, and arrives at an outlet port 23B.

[0035] An inner surface 24A which is a curved surface of the first container 24 contacts the anode cylinder 10 (refer to FIG. 2A).

[0036] Also, the main body 21 A has the first fastening portion 22A on one side surface thereof. After the cooling block 20 has been installed into the anode cylinder 10, the first screws 22B of the first fastening portion 22A is fastened so that the inner surface 24A which is the curved surface of the first container 24 contacts the anode cylinder 10 contained within the first container 24, and is fixed thereto (refer to FIG. 2A). For that reason, the main body 21A can efficiently cool the anode cylinder 10.

[0037] Also, four first screw holes 22C are formed in opposite surfaces 27A of the main body 21A, which face the magnet contact portions 21 B, so as to be continuous to respective four second screw holes 26D formed in the magnet contact portions 21 B. The first screw holes 22C receive respective third screws 26C for fixing the magnet contact portions 21 B to the main body 21A. The first screw holes 22C are so provided as to avoid the cooled liquid circulation conduit 23.

[0038] The opposite surfaces 27A facing the magnet contact portions 21 B are surfaces substantially perpendicular to the inner surface 24A of the first container 24.

[0039] The opposite surfaces 27A of the main body 21A, which face the magnet contact portions 21 B, contact upper surfaces 28B of the magnet contact portions 21 B. For that reason, the main body 21A and the magnet contact portions 21 B can thermally contact each other.

[0040] The magnet contact portions 21 B, which are separate from the main body 21A, have substantially the same shape as that of the main body 21A, but is smaller in size than the main body 21A. Each of the magnet contact portions 21 B internally includes a second container 25 that contains the annular permanent magnet 8A (or 8B). As described above, each of the magnet contact portions 21 B forms the connection portions that connect the main body 21A to the annular permanent magnet 8A or 8B when viewed from the main body 21A.

[0041] An inner surface 25A which is a curved surface of the second container 25 contacts the annular permanent magnet 8A (or 8B) (refer to FIG. 2A).

[0042] Also, the magnet contact portions 21 B each have a second fastening portion 26A on one side surface thereof. After the main body 21 A contacts and is fixed to the anode cylinder 10, a second screw 26B of the second fastening portion 26A is fastened so that the inner surface 25A that is a curved surface of the second container 25 contacts and is fixed to the annular permanent magnets 8A and 8B contained in the second container 25. For that reason, the magnet contact portions 21 B can efficiently cool the annular permanent magnets 8A and 8B.

[0043] The upper surfaces 28B of the magnet contact portions 21 B contact the opposite surfaces 27A of the main body 21A. For that reason, the magnet contact portions 21 B and the main body 21A can thermally contact each other.

[0044] Also, the magnet contact portions 21 B are fastened to the main body 21A with the four third screws 26C. The second screw holes 26D and the first screw holes 22C, which receive the third screws 26C, each have a diameter slightly larger than the diameter of the third screws 26C with an allowance. For that reason, when the magnet contact portions 21 B contact the annular permanent magnet 8A (or 8B), even if the magnet contact portions 21 B are displaced with respect to the main body 21A, the magnet contact portions 21 B can be surely fastened to the main body 21 A with the four third screws 26C.

[0045] As described above, in the magnetron 1 according to this embodiment, the magnet contact portions 21 B are provided separately from the main body 21A. This is because even if the main body 21A contacts and is fixed to the anode cylinder 10, the magnet contact portions 21 B can contact and be fixed to the annular permanent magnets 8A and 8B. For that reason, in the conventional example, when the cooling block is positioned with respect to the anode cylinder, a gap is slightly formed in a portion that contacts the permanent magnet with respect to the permanent magnet. However, in the magnetron 1 according to this embodiment, even if the main body 21 A contacts and fixed to the anode cylinder 10 for positioning, the magnet contact portions 21 B can contact and be fixed to the annular permanent magnets 8A and 8B.

[0046] Accordingly, in the magnetron 1 according to this embodiment, the cooling performance of the cooling block 20 for the annular permanent magnets 8A and 8B is kept constant and is not varied. Further, in the magnetron 1 according to this embodiment, since the respective magnet contact portions 21 B are smaller than the main body 21 A, the cooling block 20 can be prevented from being upsized.

[0047] In the magnetron 1 according to this embodiment, the main body 21A and the magnet contact portions 21 B of the cooling block 20 are made of aluminum, but are not limited to this material. There may be applicable a metal high in thermal conductivity, for example, the combination of metal such as the above-mentioned aluminum and aluminum alloy, or copper and copper alloy.

[0048] A thermal conductive paste may be coated between the inner surface 25A of the second container 25 and the annular permanent magnets 8A, 8B for the purpose of improving the thermal connection.

[0049] The thermal conductive paste may be coated between the opposite surfaces 27A of the main body 21A and the upper surfaces 28B of the magnet contact portions 21 B for the purpose of improving the thermal connection.

[0050] Thermal diffusion compound may be coated in a slight gap between an outer wall surface of the main body 21A and an inner wall surface of the magnetic yoke 4. Even if a gap accidentally occurs in the contact portion, an excellent thermal conductive state is obtained, and those members are fixed to each other on the contact portion. For that reason, the cooling block 20 can cool not only the anode cylinder 10 and annular permanent magnets 8A, 8B, but also the magnetic yoke 4 as well as the annular permanent magnets 8A, 8B and the filter 11 indirectly through the magnetic yoke 4.

(Modified Example 1)

[0051] Subsequently, a modified example 1 of the cooling block 20 in the magnetron 1 according to this embodiment will be described with reference to FIGS. 3A, 3B, and 4. FIG. 3A is a plan view of a cooling block 40, and FIG. 3B is a side view of the cooling block 40. Also, FIG. 4 is a perspective view of a magnet contact piece 41 B. Parts common to the cooling block 20 are denoted by identical symbols, and a detailed description thereof will be omitted. The cooling block 40 illustrated in FIGS. 3A and 3B includes a main portion 41A and a plurality of the magnet contact pieces 41 B.

[0052] In this example, the plurality of magnet contact pieces 41 B are connection portions that connect the main portion 41A to the annular permanent magnets 8A, 8B when viewed from the main portion 41A.

[0053] Also, the main portion 41A contacts the anode cylinder 10, and mainly cools the anode cylinder 10. On the other hand, the plurality of magnet contact pieces 41 B form the connection portions when viewed from the main portion 41A, but has a function of cooling the annular permanent magnets 8A and 8B. For that reason, the main portion 41 A and the plurality of magnet contact pieces 41 B, which configure the cooling block 40, function as a cooling member.

[0054] The main portion 41A internally includes the first container 24 that contains the anode cylinder 10 therein, and the cooled liquid circulation conduit 23. In FIG. 3A, as indicated by dashed lines, the cooled liquid circulation conduit 23 extends from the inlet port 23A, is formed inside of the main body 21A in a substantially U-shape so as to surround the anode cylinder 10, and arrives at the outlet port 23B.

[0055] Also, the main portion 41A has the first fastening portion 22A on one side surface thereof. After the cooling block 20 has been installed into the anode cylinder 10, the first screws 22B of the first fastening portion 22A are fastened so that the first container 24 contacts the anode cylinder 10 contained within the first container 24, and is fixed thereto. For that reason, the main portion 41A can efficiently cool the anode cylinder 10.

[0056] Also, ten fourth screw holes 42C are formed in surfaces of the main portion 41 A, which face the magnet contact pieces 41 B, so as to be continuous to respective third screw holes 46D formed in the magnet contact pieces 41 B. The fourth screw holes 42C receive respective fourth screws 46C for fixing the respective magnet contact pieces 41 B to the main portion 41A. The fourth screw holes 42C are so provided as to avoid the cooled liquid circulation conduit 23.

[0057] In FIG. 3B, for description, the fourth screws 46C, the fourth screw holes 42C, and the third screw holes 46D are illustrated one by one. In fact, those screws and screw holes are provided in each of the magnet contact pieces 41 B.

[0058] Subsequently, a description will be given of the magnet contact pieces 41 B with reference to FIGS. 3A, 3B, and 4. As illustrated in FIG. 4, each of the magnet contact pieces 41 B includes a horizontal portion 43 fixed to the main portion 41A, and an erect portion 44 that extends from one end of the horizontal portion 43 in a substantially perpendicular direction, and contacts the annular permanent magnets 8A and 8B.

[0059] The erect portion 44 has a surface 44A substantially perpendicular to the horizontal portion 43. The surface 44A may have a given radius of curvature so as to contact the outer peripheral surfaces of the annular permanent magnets 8A and 8B.

[0060] The horizontal portion 43 has the third screw hole 46D that penetrates through the horizontal portion 43. As described above, the third screw hole 46D is provided for inserting the fourth screw 46C thereinto. Also, as illustrated in FIG. 4, the third screw hole 46D is formed into an elongate hole, and a long axis direction (direction of an arrow X in the figure) of the third screw hole 46D coincides with a radial direction of the annular permanent magnets 8A and 8B. For that reason, after the main portion 41A has been fastened to the anode cylinder 10 contained in the first container 24, when the magnet contact piece 41 B is fastened to the main portion 41A with the fourth screw 46C, a position of the magnet contact piece 41 B to the main portion 41A can be so adjusted as to contact the annular permanent magnets 8A and 8B along the long axis direction (in other words, the radial direction of the annular permanent magnets 8A, 8B) of the third screw hole 46D. For that reason, the surface 44A of the erect portion 44 surely contacts the annular permanent magnets 8A and 8B.

[0061] Subsequently, a description will be given of a location of the magnet contact pieces 41 B with reference to FIGS. 3A and 3B.

[0062] As illustrated in FIG. 3A, the respective magnet contact pieces 41 B are arranged at regular intervals along the outer peripheral surface of the annular permanent magnets 8A and 8B. The magnet contact pieces 41 B are fastened to an upper surface (or lower surface) of the main portion 41A with the respective fourth screws 46C so that the surfaces 44A of the erect portion 44 contact the annular permanent magnet 8A (or 8B).

[0063] The third screw holes 46D that receive the respective fourth screws 46C are formed into the elongate holes for the purpose of providing a slight allowance. For that reason, even if the respective magnet contact pieces 41 B are slightly displaced with respect to the main portion 41A when the magnet contact pieces 41 B contact the annular permanent magnets 8A and 8B, the respective magnet contact pieces 41 B are fastened to the upper surface (or lower surface) of the main portion 41Awith the fourth screws 46C.

[0064] As described above, in the magnetron 1 according to this embodiment, the plurality of magnet contact pieces 41 B are disposed separately from the main portion 41A. This is because even if the main portion 41A has been positioned to the anode cylinder 10, the respective magnet contact pieces 41 B are easily positioned to and contact the annular permanent magnet 8A (or 8B). For that reason, for example, in the conventional example, when the cooling block is positioned with respect to the anode cylinder, the gap is slightly generated in a portion that contacts the permanent magnet with respect to the permanent magnet. On the other hand, in the magnetron 1 according to this embodiment, even if the main portion 41A has been positioned to the anode cylinder 10, the respective magnet contact pieces 41 B can be easily positioned to and contact the annular permanent magnets 8A and 8B.

[0065] The cooling block 40 is made of aluminum, but is not limited to this material. For example, the cooling block 40 may be made of aluminum alloy, copper, and copper alloy.

[0066] The main portion 41A and the magnet contact pieces 41B of the cooling block 40 are made of a metal having the same high thermal conductivity, but are not limited to this material. For example, there may be applicable the combination of metal such as the above-mentioned aluminum and aluminum alloy, or copper and copper alloy.

[0067] Thermal diffusion compound may be coated in a slight gap between an outer wall surface of the main portion 41A and an inner wall surface of the magnetic yoke 4. Even if a gap accidentally occurs in the contact portion, an excellent thermal conductive state is obtained, and those members are fixed to each other on the contact portion. For that reason, the cooling block 40 can cool not only the anode cylinder 10 and annular permanent magnets 8A, 8B, but also the magnetic yoke 4 as well as the annular permanent magnets 8A, 8B and the filter 11 indirectly through the magnetic yoke 4.

[0068] In the cooling block 40, the respective magnet contact pieces 41 B are screwed to the main portion 41A, individually. Alternatively, an annular magnet contact portion 61 B illustrated in FIG. 5 may be used instead of the magnet contact pieces 41 B. FIG. 5 is a perspective view of the annular magnet contact portion 61 B.

[0069] In this example, as with the magnet contact pieces 41 B, the annular magnet contact portion 61 B form a connection portion that connects the main portion 41A to the annular permanent magnets 8A, 8B.

[0070] Also, the main portion 41A contacts the anode cylinder 10, and mainly cools the anode cylinder 10. On the other hand, the annular magnet contact portion 61 B form a connection portion when viewed from the main portion 41A, but has a function of cooling the annular permanent magnets 8A and 8B. For that reason, the main portion 41A and the annular magnet contact portion 61 B, which configure the cooling block 40, function as a cooling member.

[0071] As illustrated in FIG. 5, the annular magnet contact portion 61 B includes horizontal portions 63, and an annular erect portion 64 that erects from the horizontal portions 63 in a substantially perpendicular direction.

[0072] An inner peripheral surface 64A which is a curved surface of the annular magnet contact portion 61 B contacts the outer peripheral surfaces of the annular permanent magnets 8A and 8B by fastening a third fastening portion 62A with a fifth screw 62B.

[0073] The horizontal portions 63 are arranged at regular intervals on the outer periphery of the annular erect portion 64. Also, each of the horizontal portions 63 has the third screw hole 46D for fastening the annular magnet contact portion 61 B to the main portion 41A.

[0074] The magnet contact portions 21 B, the magnet contact pieces 41 B, and the annular magnet contact portion 61 B, which function as the connection portion, may be formed of a molded member made of an insulating resin high in the thermal conductivity. For example, a material such as a filer is conceivable.

[0075] The magnet contact portions 21 B may be configured to be sandwiched between the magnetic yoke 4b and the main body 21A.

[0076] In order to fasten the first screws 22B of the first fastening portion 22A, or in order to fasten the third fastening portion 62A with the fifth screw 62B, driver insertion holes of a fixed number may be provided in the magnetic yoke 4a and 4b.

[0077] The thermal conductive paste may be replaced with a thermal conductive sheet or a fiber metal.

[0078] The present invention has been described in detail and with reference to the special embodiments. However, it would be apparent from an ordinary skilled person that the present invention can be variously changed and modified without departing from the spirit and scope of the present invention.

[0079] The present invention is based on Japanese Patent Application No. 2010-056057 filed on March 12, 2010, and content thereof is incorporated herein by reference.

Industrial Applicability

[0080] The magnetron and the device using microwaves according to the present invention has advantages of efficiently cooling the anode cylinder and the permanent magnet, and preventing the cooling member per se from being upsized while suppressing a variation of the cooling performance for the permanent magnet, and are useful as microwaves.

Description of Reference Signs

[0081] 

1: Magnetron

4: Magnetic Yoke

8A, 8B: Annular Permanent Magnet

10: Anode Cylinder

20, 40: Cooling Block

21A: Main Body

21 B: Magnet Contact Portion

24: First Container

25: Second Container

41A: Main Portion

41B: Magnet Contact Piece

61B: Annular Magnet Contact Portion

63: Horizontal Portion

64: Erect Portion

Claims

1. A magnetron comprising:

an anode cylinder;

permanent magnets disposed on both ends of the anode cylinder;

a magnetic yoke which stores the anode cylinder and the permanent magnets therein;

a cooling member which stores the anode cylinder therein and which has at least a part thereof fixed to the anode cylinder; and

a connection portion arranged between the magnetic yoke and the cooling member.

2. The magnetron according to claim 1,
wherein the connection portion allows the permanent magnet and the cooling member to contact each other.

3. The magnetron according to claim 2,
wherein an inner surface of the connection portion contacts the permanent magnet, and
wherein a surface of the connection portion substantially perpendicular to the inner surface is fixed to the cooling member.

4. The magnetron according to any one of claims 1 to 3,
wherein the connection portion is made of any one of: copper and copper alloy; and aluminum and aluminum alloy.

5. The magnetron according to any one of claims 1 to 3,
wherein the connection portion comprises a plurality of magnet contact pieces arranged along an outer peripheral surface of the permanent magnet having an annular shape, and
wherein each of the magnet contact pieces comprises:

a horizontal portion fixed to the cooling member; and

an erect portion which has a surface continuous to the horizontal portion and which contacts the outer peripheral surface of the permanent magnet.

6. The magnetron according to claim 1,
wherein the connection portion is arranged along an outer peripheral surface of the permanent magnet having an annular shape, and
wherein the connection portion comprises:

a plurality of horizontal portions fixed to the cooling member; and

an erect portion which has a surface continuous to the plurality of horizontal portion and which contacts the outer peripheral surface of the permanent magnet.

7. The magnetron according to any one of claims 1, 5 and 6,
wherein the connection portion is formed of a molded member made of an insulating resin having high thermal conductivity.

8. The magnetron according to claim 7,
wherein a thermal conductive paste is coated between: the connection portion and the permanent magnet; and/or the connection portion and the cooling member.

9. A device using microwaves, comprising the magnetron according to any one of claims 1 to 8.

Drawing