Abstract: An antenna part of a magnetron includes an exhaust portion that is connected to an antenna conductor derived from an anode part and has an output terminal from which a microwave is outputted, and an output-side ceramic stem that holds internally the antenna conductor and is firmly fixed to the exhaust portion to insulate electrically a side pipe connected to the anode part of a main body of the magnetron from the exhaust portion. An antenna part further includes an antenna cap that is joined to the exhaust portion by a conductive adhesive arranged on an outer periphery of the exhaust portion. Accordingly, it is possible to provide the magnetron that can prevent occurrence of electric discharge between the antenna cap and the exhaust portion.

Abstract: An antenna part of a magnetron includes an exhaust portion that is connected to an antenna conductor derived from an anode part and has an output terminal from which a microwave is outputted, and an output-side ceramic stem that holds internally the antenna conductor and is firmly fixed to the exhaust portion to insulate electrically a side pipe connected to the anode part of a main body of the magnetron from the exhaust portion. An antenna part further includes an antenna cap that is joined to the exhaust portion by a conductive adhesive arranged on an outer periphery of the exhaust portion. Accordingly, it is possible to provide the magnetron that can prevent occurrence of electric discharge between the antenna cap and the exhaust portion.

Abstract: A magnetron includes: an anode tube; and cooling fins placed on a periphery of the anode tube and arranged along a central axis of the anode tube. Each of the cooling fins includes at least two sets of fins formed by cutting a part of the cooling fin, and performing different bending works on the cut portions, respectively, so as to form a region where the cooling fins are dense and a region where the cooling fins are sparse, when viewed in a flowing direction of a cooling medium which cools the anode tube through the cooling fins. The at least two sets of fins are bent at bending angles such that intervals of the cooling fins in the region where the cooling fins are dense are ½ or less of placement intervals of the cooling fins.

Abstract: A magnetron includes an anode cylinder which has a cylindrical shape with both ends opened and which includes a plurality of vanes radially provided on an inner wall surface thereof, a pair of pole pieces positioned in openings of the both ends of the anode cylinder, and metal sleeves. The metal sleeves are positioned outside the pair of pole pieces and configured to air-tightly seal the anode cylinder. Each of the metal sleeves includes a cylinder part, a flange part continuous with the cylinder part, and a plurality of protrusions provided on a portion in which the cylinder part continues with the flange part.

Abstract: A magnetron includes: an anode cylinder including anode vanes provided at a predetermined interval on an inner peripheral surface thereof; a center lead including a first linear portion, a second linear portion disposed parallel to the first linear portion and disposed out of alignment with the first linear portion in a plane perpendicular to an axial direction of the anode cylinder, and a bent portion which connects the first linear portion to the second linear portion; and a cathode filament supported by the center lead within the anode cylinder and placed coaxially with the anode cylinder. The center lead is formed so as to become bent between the first linear portion and the second linear portion by the bent portion. A position of one anode vane closest to the bent portion is higher than a position of another anode vane with respect to the axial direction.

Abstract: A magnetron includes an anode cylinder; a cathode side tube hermetically coupled to a lower portion of the anode cylinder; and a shield cylinder. The shield cylinder includes a cylindrical part extending in substantially a vertical direction, a flange part which is connected to the cylindrical part and extends in substantially a horizontal direction over the entire periphery of the cylindrical part, and a folded part in which a portion of the flange part is folded toward the cathode side tube. The shield cylinder is electrically coupled to the cathode side tube at a lower end of the anode cylinder.

Abstract: A magnetron includes: an anode tube; and cooling fins placed on a periphery of the anode tube, and arranged along a central axis of the anode tube. Each of the cooling fins includes at least two sets of fins formed by cutting a part of the cooling fin, and performing different bending works on the cut portions, respectively, so as to form a region where the cooling fins are dense and a region where the cooling fins are sparse, when viewed in a flowing direction of a cooling medium which cools the anode tube through the cooling fins. The at least two sets of fins are bent at bending angles such that intervals of the cooling fins in the region where the cooling fins are dense are ½ or less of placement intervals of the cooling fins.

Abstract: The magnetron includes: an exhaust pipe in which an antenna is disposed in a vacuum-sealed space, and which extends along the central axis of the antenna; an insulation tube which extends along the central axis of the antenna, and of which one end is fixed to the exhaust pipe by brazing; and an antenna cap including a bottom portion and a tubular portion which is continuous with the bottom portion to extend along the axis of the antenna and of which a diameter on an open end side is larger than a diameter of the exhaust pipe. The tubular portion of the antenna cap covers: a brazed portion where the exhaust pipe and the insulation tube are brazed to each other; and a metalized portion.

Abstract: To provide a magnetron capable of reducing noises in a low frequency band of 30 MHz or less without deteriorating the stability of a load depending on phases, and also ensuring the precision of assembly dimensions without increasing the number of components, a coiled filament 3 is arranged between an input-side end hat 61 and an output-side end hat 7 which are supported by a cathode supporting rod 8. A larger-diameter boss 61a in the end hat 61 extends to the interior of an interaction space, a smaller-diameter boss 61b and one end 3a of the filament 3 are secured to each other, and the other end 3b is secured to a boss 7a of the end hat 7. Here, the dimension of an axial free length part F which forms an electron emission part which is not secured to the end hats 61 and 7 of the filament 3 is set to 50% or more and 80% or less of the axial dimension H of plate-like vanes 2, and the electron emission part is arranged so as to be displaced to the output side.

Abstract: The present invention provides a magnetron which can conduct more magnetic flux in the active space at the periphery of a cathode structure to thereby further improve the efficiency of a magnetic circuit. The magnetron of the present invention includes an anode cylinder on which inner wall a plurality of anode vanes are provided, a pole piece provided on an end side of the anode cylinder, a circular magnet provided on the vicinity of the pole piece, and a magnet ring provided between the anode cylinder and the circular magnet. An outer diameter of the magnet ring is smaller than or equal to the outer diameter of the circular magnet and larger than or equal to the outer diameter of the anode cylinder. The magnet ring has a portion on a surface of the pole piece side whose normal line is non-parallel to the central axis of the anode cylinder.

Abstract: Performance degradation of a magnetron is prevented by preventing a cylinder part of a metal sleeve from sinking in a recess of a pole piece even when subjected to a high pressure in the case of handling or assembly.

Abstract: A magnetron for holding deformation of a cathode side tube for alignment of a cathode filament and eliminating the need for alignment at the time of exterior assembly work of the magnetron is provided. The magnetron of the invention includes an anode cylinder; a cathode side tube hermetically coupled to a lower portion of the anode cylinder; and a shield cylinder having a cylindrical part extending in substantially a vertical direction, a flange part which is connected to the cylindrical part and extends in substantially a horizontal direction over the entire periphery of the cylindrical part, and a folded part in which a portion of the flange part is folded toward the cathode side tube, the shield cylinder being electrically coupled to the cathode side tube at a lower end of the anode cylinder.

Abstract: To provide a magnetron capable of suppressing generation of a reactive current and noise thereby improving oscillation efficiency, and a device using microwaves which includes the magnetron. A magnetron of the present invention includes: an anode cylinder including a plurality of anode vanes provided at a predetermined interval on an inner peripheral surface thereof; a center lead including a first linear portion, a second linear portion which is disposed parallel to the first linear portion and which is disposed out of alignment with the first linear portion in a plane perpendicular to an axial direction of the anode cylinder, and a bent portion which connects the first linear portion to the second linear portion; and a cathode filament which is supported by the center lead within the anode cylinder and which is placed coaxially with the anode cylinder. The center lead is formed so as to become bent between the first linear portion and the second linear portion by the bent portion.

Abstract: In each anode vane 10, there is provided the brazing material spreading prevention groove 13 that interconnects the strap ring inserting portions 11 and 12 in parallel to the direction of the central axis Ax. With such a configuration, it is possible to prevent the residual brazing material 3a from spreading to the front end part 10a of the anode vane 10 when each anode vane 10 is brazed on the inner peripheral surface of the anode cylinder 1. Therefore, non-uniformity in thickness of the anode vanes 10 caused by the residual brazing material 3a is suppressed, and electrostatic capacity between the anode vanes 10 adjacent to each other becomes substantially constant. Thus, it is possible to obtain stable resonant frequency. In addition, it becomes easy to perform adjustment for obtaining the stable resonant frequency in that non-uniformity in initial frequency of the time when the magnetron is completely assembled decreases.

Abstract: The magnetron includes: a cylindrical-shaped anode barrel member 10 having two openings respectively formed in the two end portions thereof; a cathode structure member 12 disposed on the center axis of the anode barrel member 10; more than one anode vane 11 disposed radially through an action space 13 in the periphery of the cathode structure member 12 and fixedly mounted on the inner wall surface of the anode barrel member 10; and, a pair of funnel-shaped pole pieces 14 and 30 respectively disposed in their associated ones of the two openings formed in the two end portions of the anode barrel member 10, each pole piece including a small-diameter flat portion FL1 having a penetration hole formed in the central portion thereof, a large-diameter flat portion FL2 having a diameter larger than the diameter of the small-diameter flat portion FL1, and a conical-shaped slanting portion SL for connecting the large-diameter flat portion FL2 and small-diameter flat portion FL1 to each other.

Abstract: In the magnetron, an upper end hat 122A is used as a composing element of a cathode structure member 12A and includes a portion 122Aa which is in contact with one end portion 121a of a filament coil 121. The thickness of the portion 122Aa is reduced, whereby the portion 122Aa is held not in contact with a center lead 124. Owing to this, heat generated in the filament coil 121 can travel to the upper end hat 122A without traveling directly to the center lead 124. Therefore, even when the quantity of input power is reduced to such a degree as to be able to reduce noise, or even when the electron radiation area of the filament coil 121 is reduced, the getter effect can be displayed fully. As a result of this, noise reduction and cost reduction can be realized at the same time.

Abstract: It is an object to provide a magnetron for a small-sized microwave oven which takes safety standards and a noise into consideration, in a magnetron 10 for a microwave oven, a pair of choke coils 16 and 17 are provided in a filter case 11, and a height H1 of the internal surface of the filter case 11 is set to be 35 to 45 mm, an outside diameter d3 of an air-core type inductance 25 is set to be 5.5 to 7.5 mm and a sectional area S of a high frequency absorbing member 27 is set to be 5 to 16 mm2. In the magnetron 10 for a microwave oven, an electrostatic capacity between capacitor terminals 15A and 15B and the filter case 11 is increased to be 500 to 700 pF.

Abstract: The present invention provides a magnetron which can conduct more magnetic flux in the active space at the periphery of a cathode structure to thereby further improve the efficiency of a magnetic circuit. The magnetron of the present invention includes an anode cylinder on which inner wall a plurality of anode vanes are provided, a pole piece provided on an end side of the anode cylinder, a circular magnet provided on the vicinity of the pole piece, and a magnet ring provided between the anode cylinder and the circular magnet. An outer diameter of the magnet ring is smaller than or equal to the outer diameter of the circular magnet and larger than or equal to the outer diameter of the anode cylinder. The magnet ring has a portion on a surface of the pole piece side whose normal line is non-parallel to the central axis of the anode cylinder.

Abstract: In each anode vane 10, there is provided the brazing material spreading prevention groove 13 that interconnects the strap ring inserting portions 11 and 12 in parallel to the direction of the central axis Ax. With such a configuration, it is possible to prevent the residual brazing material 3a from spreading to the front end part 10a of the anode vane 10 when each anode vane 10 is brazed on the inner peripheral surface of the anode cylinder 1. Therefore, non-uniformity in thickness of the anode vanes 10 caused by the residual brazing material 3a is suppressed, and electrostatic capacity between the anode vanes 10 adjacent to each other becomes substantially constant. Thus, it is possible to obtain stable resonant frequency. In addition, it becomes easy to perform adjustment for obtaining the stable resonant frequency in that non-uniformity in initial frequency of the time when the magnetron is completely assembled decreases.

Abstract: For an anode assembly 51 of a magnetron, a plurality of plate shaped vanes 54 radially arranged at an inner circumference of the roughly round shaped anode assembly 53 has a end portion arranged at a central axis of the anode assembly 53 with a step shape Df having a reduced thickness in a range of predetermined length L from an end portion, so that increase of the facing area of the respective adjacent plate shaped vanes 54 is suppressed while the separation distance of the end portions of the vanes is secured.