JP2013206731A - Magnetron and microwave oven using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently cool down a magnetron and its power supply.SOLUTION: A magnetron comprises: a magnetron main body having an anode cylinder extending along the center shaft, and the like; and a cooling fin 25. To the cooling fin 25, a hole 75 to which the anode cylinder is fitted, and a slit 74 between this hole 75 and an end part are formed. To this magnetron having the cooling fin 25 and to a high-voltage transformer arranged on an input side of the magnetron, cooling air is hit in a direction from the slit 74 side toward the center shaft of the magnetron. There are a plurality of cooling fins 25, and as it goes from the input side to the output side, the position of the slit 74 approaches the center shaft of the magnetron.

Description

  The present invention relates to a magnetron and a microwave oven using the magnetron.

  Magnetrons are built into microwave ovens and are used for many purposes such as cooking and thawing foods. An output antenna protrudes from the output side of the upper end of the magnetron body. A filter circuit including a coil and a feedthrough capacitor housed in a filter box is connected to the input side at the lower end of the magnetron body. Permanent magnets are arranged on the upper and lower ends of the magnetron body. A yoke is disposed so as to surround the magnetron body and the permanent magnet, and a magnetic circuit is formed.

  A plurality of cooling fins are press-fitted into the magnetron main body and spread between the yokes to constitute a radiator (see, for example, Patent Document 1). The yoke is provided on both sides of the shaft so as to sandwich the magnetron body. The yoke is provided in a part of the periphery of the shaft of the magnetron body, and openings are formed on both sides of the shaft. These openings serve as inlets and outlets for cooling air.

  A high-voltage transformer serving as a magnetron power supply is often arranged on the input side on the axis of the magnetron body.

JP 2012-054010 A

  The magnetron generates heat when generating electromagnetic waves in the magnetron body and the filter circuit on the input side. In addition, the high-voltage transformer that is the power source of the magnetron also generates heat during operation. For this reason, in order to operate a magnetron appropriately, appropriate cooling is required.

  Therefore, in a general microwave oven, cooling air is generated and cooled by high-pressure transformers arranged linearly, a filter box, and a fan toward the magnetron body. However, if you try to apply cooling air directly to the entire high-voltage transformer, filter box, and magnetron body with a fan, the fan will be large or multiple fans will be required, consuming a lot of energy, The device becomes large.

  Therefore, an object of the present invention is to enable efficient cooling of the magnetron and its power supply.

  In order to solve the above-described problems, the present invention provides a magnetron, wherein a cylindrical anode extending from the input side to the output side, a plurality of vanes extending from the inner wall of the anode toward the axis of the anode, and the inside of the anode A magnetron body having a cathode extending along an axis, a support rod drawn out to the input side to support the cathode, and an antenna drawn out from one of the vanes to the output side, and an interval in contact with the outer wall of the anode And a plurality of cooling fins formed with slits penetrating in the thickness direction. The cooling fins are the first cooling fins and the first cooling fins. A second cooling fin that is in contact with the outer wall of the anode on the output side of the cooling fin, and the slit formed in the second cooling fin includes the first cooling fin. Characterized in that close to said axis than said formed slit.

  In the microwave oven according to the present invention, a cylindrical anode extending from the input side to the output side, a plurality of vanes extending from the inner wall of the anode toward the axis of the anode, and the axis extending inside the anode along the axis. A magnetron body having a cathode, a support rod drawn to the input side and supporting the cathode, and an antenna drawn from one of the vanes to the output side, and in a direction crossing the axis in contact with the outer wall of the anode A cooling fin that is a spreading plate and is formed with a slit penetrating in the thickness direction, the cooling fin being on the outer wall of the anode on the output side of the first cooling fin and the first cooling fin. The slit formed in the second cooling fin is closer to the axis than the slit formed in the first cooling fin. Ron, a high-pressure transformer that is disposed outside the input side of the magnetron of the shaft and supplies power to the magnetron body, and a fan that generates wind that reaches the magnetron body and the high-voltage transformer toward the shaft It is characterized by comprising.

  According to the present invention, the magnetron and its power supply can be efficiently cooled.

It is a longitudinal cross-sectional view in one Embodiment of the magnetron based on this invention. It is a side view of the magnetron and high voltage transformer in one embodiment of the magnetron according to the present invention. It is a bottom view of the cooling fin in one embodiment of the magnetron concerning the present invention. It is a side view of the cooling fin in one embodiment of the magnetron concerning the present invention. It is a VV arrow sectional view of Drawing 4. It is a typical horizontal sectional view of the microwave oven using one embodiment of the magnetron concerning the present invention. It is a top view of the modification of the cooling fin of one embodiment of the magnetron according to the present invention. It is a top view of the modification of the cooling fin of one embodiment of the magnetron according to the present invention.

  An embodiment of a magnetron according to the present invention will be described with reference to the drawings. Note that this embodiment is merely an example, and the present invention is not limited thereto.

  FIG. 1 is a longitudinal sectional view of an embodiment of a magnetron according to the present invention.

  The magnetron 50 of the present embodiment includes an anode cylinder 1, a cathode 5, a pair of end hats 6, 7 and a pair of pole pieces 8, 9 disposed along the central axis 41, and the vicinity of the central axis 41. A plurality of vanes 2 extending radially are provided. The anode cylinder 1 extends in a cylindrical shape along the central axis 41.

  The vane 2 extends radially from the vicinity of the central axis 41 and is fixed to the inner surface of the anode cylinder 1. The vanes 2 are each formed in a substantially rectangular plate shape. The free end 31 of the vane 2 on the side not fixed to the inner surface of the anode cylinder 1 is disposed on the same cylindrical surface extending along the central axis 41, and this cylindrical surface is referred to as a vane inscribed cylinder. The plurality of vanes 2 are connected to each other in the circumferential direction by strap rings 3 and 4 that are paired in large and small brazed to the upper and lower ends of the vane.

  The cathode 5 is spiral and is disposed on the central axis of the anode cylinder 1. Further, both ends of the cathode 5 are fixed to the end hats 6 and 7, respectively. The end hats 6 and 7 are disposed outside the central axis 41 with respect to the vane 2.

  The pair of pole pieces 8 and 9 are each formed in a funnel shape having a through hole 32 at the center. The center of the through hole 32 is located on the central axis 41. Each pole piece 8, 9 is formed so as to spread from the through hole 32 toward the outside of the central axis 41 with respect to the space sandwiched between the end hats 6, 7. The outer diameters of the pole pieces 8 and 9 are formed substantially the same as the diameter of the anode cylinder 1. The outer peripheral portions of the pole pieces 8 and 9 are fixed to both ends of the anode cylinder 1 respectively. Further, the pair of pole pieces 8 and 9 are arranged with a space between the end hats 6 and 7 interposed therebetween.

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

  An output-side ceramic 12 is joined to the end of the output-side metal seal 10 opposite to the pole piece 8. An exhaust pipe 13 is joined to the end of the output side ceramic 12 opposite to the metal sealing body 10. A bar-shaped antenna 14 made of copper is led out from one of the vanes 2. The antenna 14 passes through the output-side pole piece 8, extends in the output portion onto the central axis 41, and the tip is sandwiched and fixed by the exhaust pipe 13. The entire exhaust pipe 13 is covered with a cap 15.

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

  Further, the magnets 21 and 22 and the yokes 23 and 24 are disposed so as to surround the magnetron main body which is such an oscillating portion, thereby forming a magnetic circuit. The yokes 23 and 24 are bent plates, respectively, and surround the magnetron body with the central axis 41 interposed therebetween. In the space surrounded by the yokes 23, 24, an opening 62 is formed so as to face each other with the central axis 41 interposed therebetween.

  Cooling fins 25 for cooling the oscillation unit main body are provided in the space surrounded by the yokes 23 and 24. A filter circuit having a coil 33 and a feedthrough capacitor 34 is connected to the cathode 5 via support rods 17 and 18. The coil 33 and feedthrough capacitor 34 constituting the filter circuit are housed in a filter box 27.

  FIG. 2 is a side view of the magnetron and the high-voltage transformer in the present embodiment.

  The magnetron 50 and the high voltage transformer 51 are disposed along the central axis 41 of the magnetron 50. On the output side of the magnetron 50, the exhaust pipe 13 (see FIG. 1) covered with the cap 15 is located. The high voltage transformer 51 is disposed on the input side to which the filter box 27 is attached.

  A fan 60 is disposed in the vicinity of the magnetron 50 and the high-voltage transformer 51. The fan 60 is rotated by a driving mechanism such as a motor (not shown) to generate cooling air 61 that flows toward the central axis 41 of the magnetron 50. The fan 60 faces one of the openings 62 surrounded by the yokes 23 and 24. The cooling air 61 flows from the opening 62 into the space surrounded by the yokes 23 and 24 and flows out from the other opening 62. The fan 60 does not need to generate the cooling air 61 from the high-voltage transformer 51 to the entire output portion of the magnetron 50, and is at least a region surrounded by the filter box 27 and the yokes 23 and 24 on the magnetron 50 side of the high-pressure transformer. As long as it can generate the cooling air 61 directed to a part of the input side.

  FIG. 3 is a bottom view of the cooling fin in the present embodiment. FIG. 4 is a side view of the cooling fin in the present embodiment. 5 is a cross-sectional view taken along line VV in FIG. In FIG. 5, the cooling fins arranged on the input side with respect to the cooling fins shown in FIG. 4 are shown by broken lines together with the central axis 41 of the magnetron main body.

  The cooling fin 25 has a rectangular flat plate portion 70 and protruding portions 71 and 72 protruding from the long sides thereof. One protruding portion 71 is bent upward at a point where it is bent downward from the flat plate portion 70. The other projecting portion 72 is bent upward from the flat plate portion 70. The sides of the protruding portions 71 and 72 opposite to the flat plate portion 70 are bent so as to be in contact with the yoke 24.

  A circular hole 75 having an inner diameter substantially the same as the outer diameter of the anode cylinder 1 passes through the center of the flat plate portion 70. A cylindrical contact surface 73 that contacts the anode cylinder 1 extends downward around the hole 75.

  In the flat plate portion 70, a slit 74 parallel to the short side is formed. A plate-like protrusion 76 protrudes downward on the side close to the hole 75 of the slit 74.

  The cooling fin 25 is attached to the anode cylinder 1 such that the anode cylinder 1 is fitted into a hole 75 formed in the flat plate portion 70 and the cylinder contact surface 73 is in contact with the outer surface of the anode cylinder 1. There are a plurality of cooling fins 25 attached to the anode cylinder 1.

  Each cooling fin 25 has a different position of the slit 74. The position of the slit 74 approaches the anode cylinder 1, that is, the central axis 41 as the mounting position of the cooling fin 25 moves from the output side to the input side.

  In the magnetron using such a cooling fin 25, the cooling air 61 generated toward the central axis 41 by the fan 60 flows in the axial direction through the slit 74 provided in the cooling fin 25. For this reason, even if the cooling air 61 flows only in the vicinity of the input side of the opening 62 of the yokes 23 and 24, it flows to the output side through the slit 74, so that the anode cylinder 1 has a wide axial region. The cooling air 61 hits, and the cooling efficiency of the magnetron body is improved.

  Further, the slit 74 approaches the central axis 41 from the input side toward the output side. Since the flow of the cooling air 61 has a large component toward the central axis 41, the cooling air 61 easily passes through the slit 74 and is sequentially sent to the area partitioned by the slit 74 from the input side to the output side. Furthermore, since the protrusion 76 protrudes from the input side surface of the slit 74, the cooling air 61 hitting the protrusion 76 is sent from the input side to the output side with respect to the cooling fin 25.

  As described above, in the magnetron of the present embodiment, the magnetron can be efficiently cooled without changing the size of the fan 60. At this time, since it is not necessary to change the supply amount of the cooling air 61 to the high-voltage transformer serving as the power source, the cooling efficiency of the magnetron power source can be maintained.

  The cooling fins 25 are preferably formed rotationally symmetrically about the hole 75 into which the anode cylinder 1 is fitted. By forming it rotationally symmetrical, the direction of the cooling fin 25 is not mistaken when the cooling fin 25 is attached to the anode cylinder 1. Furthermore, even if the cooling air 61 is introduced from either side of the two openings 62 of the yokes 23 and 24, the cooling efficiency is similarly improved.

  It is preferable that the projection 76 protruding from the slit 74 formed in the cooling fin 25 and the cylindrical contact surface 73 around the hole 75 of the flat plate portion 70 protrude on the same side with respect to the flat plate portion 70. It is because it can shape | mold by press work simultaneously by making it protrude in the same direction.

  FIG. 6 is a schematic horizontal sectional view of a microwave oven using the magnetron of the present embodiment.

  The microwave oven 80 includes a casing 82, a magnetron 50, and a fan 60. The housing 82 is a rectangular parallelepiped box, and an inflow hole 81 and an outflow hole 86 are formed on a side surface. Inside the housing 82, a heating chamber 83 in which an object to be heated is arranged is provided. An openable / closable door 84 for accessing the heating chamber 83 is provided on the front surface of the housing 82. An operation panel 85 for operating the microwave oven is attached to the front surface of the housing 82.

  The magnetron 50 is arranged, for example, beside the heating chamber 83 so that the central axis 41 (see FIG. 1) faces in the vertical direction and the output side is on the upper side. The electromagnetic wave output from the magnetron 50 is guided to the heating chamber 83 by a waveguide (not shown).

  Due to the rotation of the fan 60, outside air is taken into the housing 82 from the inflow hole 81 of the housing 82 and used for cooling the magnetron 50 and the high-voltage transformer 51. Cooling air that has cooled the magnetron 50 and the like passes through a heating chamber 83 partially formed of punching metal, for example, and is discharged from the outflow hole 86 to the outside of the housing 82.

  Thus, according to the present embodiment, the magnetron and its power supply can be efficiently cooled.

  7 and 8 are top views of modified examples of the cooling fins of the magnetron according to the present embodiment.

  In these modified examples, the shape of the slit 74 is changed. The slit 74 may be formed by arranging a plurality of circular holes 91 as shown in FIG. 7 in addition to the rectangle shown in FIG. Alternatively, a triangular slit 92 may be provided. Regardless of the shape of the slit, it is preferable to bring the slit closer to the central axis 41 as the mounting position of the cooling fin 25 moves from the input side to the output side of the magnetron 50.

DESCRIPTION OF SYMBOLS 1 ... Anode cylinder, 2 ... Vane, 3 ... Strap ring, 4 ... Strap ring, 5 ... Cathode, 6 ... End hat, 7 ... End hat, 8 ... Pole piece, 9 ... Pole piece, 10 ... Metal sealing body, DESCRIPTION OF SYMBOLS 11 ... Metal sealing body, 13 ... Exhaust pipe, 14 ... Antenna, 15 ... Cap, 16 ... Input side ceramic, 17 ... Support rod, 18 ... Support rod, 19 ... Relay plate, 21 ... Magnet, 22 ... Magnet, 23 ... Yoke, 24 ... Yoke, 25 ... Cooling fin, 27 ... Filter box, 31 ... Free end, 33 ... Coil, 34 ... Penetration capacitor, 41 ... Center axis, 50 ... Magnetron, 51 ... High pressure transformer, 60 ... Fan, 61 ... Cooling air, 62 ... Opening, 70 ... Flat plate part, 71 ... Projection part, 72 ... Projection part, 73 ... Cylindrical contact surface, 74 ... Slit, 75 ... Hole, 76 ... Projection, 8 ... microwave, 81 ... inlet, 82 ... housing, 83 ... heating chamber, 84 ... door, 85 ... operation panel 86 ... outlet hole

Claims (5)

A cylindrical anode extending from the input side to the output side, a plurality of vanes extending from the inner wall of the anode toward the axis of the anode, a cathode extending along the axis inside the anode, and the input side being drawn out to the input side A magnetron body having a support rod supporting a cathode and an antenna drawn out from one of the vanes to the output side;
A plurality of cooling fins which are provided in contact with the outer wall of the anode and are spaced apart and spread in a direction crossing the axis, and formed with slits penetrating in the plate thickness direction;
The cooling fin includes a first cooling fin and a second cooling fin that is in contact with the outer wall of the anode on the output side with respect to the first cooling fin, and is formed in the second cooling fin. The magnetron is characterized in that the slit is closer to the axis than the slit formed in the first cooling fin. A magnet that forms a magnetic field inside the anode;
A ferromagnetic yoke that forms a magnetic path of magnetic flux generated by the magnet surrounding the magnetron body, the magnet, and the cooling fin so as to form two openings facing each other across the shaft;
The magnetron according to claim 1, further comprising: the slit formed between the two openings.   3. The magnetron according to claim 1, wherein the cooling fin includes a projecting portion that projects toward an input side from an end edge of the slit close to the axis.   4. The magnetron according to claim 1, wherein the cooling fins are symmetric about the axis. 5. A cylindrical anode extending from the input side to the output side, a plurality of vanes extending from the inner wall of the anode toward the axis of the anode, a cathode extending along the axis inside the anode, and the input side being drawn out to the input side A magnetron body having a support rod supporting a cathode and an antenna drawn out from one of the vanes to the output side, and a plate extending in a direction crossing the axis in contact with the outer wall of the anode and penetrating in the plate thickness direction A cooling fin having a slit formed thereon, the cooling fin including a first cooling fin and a second cooling fin in contact with the outer wall of the anode on the output side of the first cooling fin, The slit formed in the second cooling fin includes a magnetron closer to the axis than the slit formed in the first cooling fin;
A high-voltage transformer disposed outside the input side of the magnetron of the shaft and supplying power to the magnetron body;
A fan that generates wind that reaches the magnetron body and the high-voltage transformer toward the shaft;
A microwave oven comprising:

Images