Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Matsushita Electric Industrial Co., Ltd.

Nagisa Kuwahara

Takeshi Ishii

Masayuki Aiga

Etsuo Saitou

Takanori Handa

Hiroshi Ochiai

Kohei Kawata

Kazuyasu Akutsu

Ayako Kumakura

Yoshimasa Suzuki

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.

Magnetron

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 &#xbd; or less of placement intervals of the cooling fins.

Magnetron and apparatus that uses microwaves

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.

Magnetron and microwave utilization device

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.

Magnetron and device using microwaves

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.

Magnetron and microwave-using equipment

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 filamentis arranged between an input-side end hatand an output-side end hatwhich are supported by a cathode supporting rod. A larger-diameter bossin the end hatextends to the interior of an interaction space, a smaller-diameter bossand one endof the filamentare secured to each other, and the other endis secured to a bossof the end hat. Here, the dimension of an axial free length part F which forms an electron emission part which is not secured to the end hatsandof the filamentis set to 50% or more and 80% or less of the axial dimension H of plate-like vanes, and the electron emission part is arranged so as to be displaced to the output side.

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.

In each anode vane, there is provided the brazing material spreading prevention groovethat interconnects the strap ring inserting portionsandin parallel to the direction of the central axis Ax. With such a configuration, it is possible to prevent the residual brazing materialfrom spreading to the front end partof the anode vanewhen each anode vaneis brazed on the inner peripheral surface of the anode cylinder. Therefore, non-uniformity in thickness of the anode vanescaused by the residual brazing materialis suppressed, and electrostatic capacity between the anode vanesadjacent 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.

Magnetron and method of manufacturing magnetron anode vane

The magnetron includes: a cylindrical-shaped anode barrel memberhaving two openings respectively formed in the two end portions thereof; a cathode structure memberdisposed on the center axis of the anode barrel member; more than one anode vanedisposed radially through an action spacein the periphery of the cathode structure memberand fixedly mounted on the inner wall surface of the anode barrel member; and, a pair of funnel-shaped pole piecesandrespectively disposed in their associated ones of the two openings formed in the two end portions of the anode barrel member, each pole piece including a small-diameter flat portion FLhaving a penetration hole formed in the central portion thereof, a large-diameter flat portion FLhaving a diameter larger than the diameter of the small-diameter flat portion FL, and a conical-shaped slanting portion SL for connecting the large-diameter flat portion FLand small-diameter flat portion FLto each other. Of the pair of pole piecesand, the input side pole pieceincludes, besides the penetration holeA formed in the central portion thereof, three or more, preferably, four penetration holesB respectively formed in the slanting portion SL thereof, each hole having an area of 16.6 mm.

In the magnetron, an upper end hatA is used as a composing element of a cathode structure memberA and includes a portionAa which is in contact with one end portionof a filament coil. The thickness of the portionAa is reduced, whereby the portionAa is held not in contact with a center lead. Owing to this, heat generated in the filament coilcan travel to the upper end hatA without traveling directly to the center lead. 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 coilis 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.

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 magnetronfor a microwave oven, a pair of choke coilsandare provided in a filter case, and a height Hof the internal surface of the filter caseis set to be 35 to 45 mm, an outside diameter dof an air-core type inductanceis set to be 5.5 to 7.5 mm and a sectional area S of a high frequency absorbing memberis set to be 5 to 16 mm. In the magnetronfor a microwave oven, an electrostatic capacity between capacitor terminalsA andB and the filter caseis increased to be 500 to 700 pF.

Magnetron for microwave oven

For an anode assemblyof a magnetron, a plurality of plate shaped vanesradially arranged at an inner circumference of the roughly round shaped anode assemblyhas a end portion arranged at a central axis of the anode assemblywith 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 vanesis suppressed while the separation distance of the end portions of the vanes is secured.

A magnetron comprising an anode portion having an anode cylinder and vanes, a cathode portion having a coil-shaped filament, magnetic poles disposed at the upper and lower ends of the filament, ring-shaped permanent magnets made of a Sr ferrite magnet containing La&#x2014;Co, an input portion and an output portion. The diameter &#x3c6;a of the inscribed circle at the ends of the vanes constituting the anode portion is in the range of 7.5 to 8.5 mm, and the outside diameter &#x3c6;c of the coil-shaped filamentconstituting the cathode portion is in the range of 3.4 to 3.6 mm.

In a magnetron apparatus in accordance with the present invention, a first notch , a second notch and a third notch are formed in each of anode segments disposed radially inside an anode cylinder , whereby the passage of high-frequency current flowing through the resonator comprising the two anode segments adjacent to each other, the anode cylinder and strap rings and is made narrow and long.

Growing community of inventors

Tochigi, Japan

Nagisa Kuwahara