US 9,852,872 B2 · Magnetron

Abstract

Provided is a low-cost magnetron that is excellent in productivity without any adverse effect on characteristics. Two large and small strap rings 11 (11A and 11B) are only disposed at lower ends, or input sides, of a plurality of vanes 10 (10A and 10B) in the direction of a tube axis m. Diameter Rip of a protruding flat surface 41 of an input side pole piece 18 is larger than diameter Rop of a protruding flat surface 40 of an output side pole piece 17. Therefore, it is possible to provide a practical magnetron without a significant decrease in productivity or characteristics from a conventional one, while cutting costs by reducing the number of parts with the use of two strap rings on one side.

Drawings

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Drawings

Claims12

Dependent claims

A magnetron comprising:

an anode cylinder extending cylindrically along a tube axis;
a plurality of vanes extending from an inner surface of the anode cylinder toward the tube axis with free ends forming a vane inscribed circle;
a large strap ring and a small strap ring with respective different diameters and short-circuiting alternating ones of the plurality of vanes;
a cathode disposed along the tube axis in the vane inscribed circle formed by the free ends of the plurality of vanes;
pole pieces disposed at both ends of the anode cylinder in a tube axis direction to lead magnetic flux into an interaction space between the free ends of the plurality of vanes and the cathode;
and
an antenna extending from at least one of the vanes,
characterized in that:
the strap rings are only disposed on a cathode input side end, in the tube axis direction, of the vanes,
the shape of the pole piece disposed at one end of the anode cylinder in the tube axis direction and the shape of the pole piece disposed at the other end are asymmetrical, and
the pole pieces disposed at both ends of the anode cylinder in the tube axis direction include protruding flat surfaces, and a diameter of the protruding flat surface of the pole piece disposed at one end of input side is larger than a diameter of the protruding flat surface of the pole piece disposed at the other end of output side, wherein
a diameter (Rop) of the protruding flat surface of the pole piece disposed at the output side, a diameter (Rip) of the protruding flat surface of the pole piece disposed at the input side, an inner diameter (Rsi) of the small strap ring, and an outer diameter (Rlo) of the large strap ring satisfy the following conditional expression (1):
Rop<(Rsi+Rlo)/2≦Rip. (1)

10 more elements

A magnetron comprising:

an anode cylinder extending cylindrically along a tube axis;
a plurality of vanes extending from an inner surface of the anode cylinder toward the tube axis with free ends forming a vane inscribed circle;
a large strap ring and a small strap ring with respective different diameters and short-circuiting alternating ones of the plurality of vanes;
a cathode disposed along the tube axis in the vane inscribed circle formed by the free ends of the plurality of vanes;
pole pieces disposed at both ends of the anode cylinder in a tube axis direction to lead magnetic flux into an interaction space between the free ends of the plurality of vanes and the cathode;
and
an antenna extending from at least one of the vanes,
characterized in that:
the strap rings are only disposed on a cathode input side end, in the tube axis direction, of the vanes,
the shape of the pole piece disposed at one end of the anode cylinder in the tube axis direction and the shape of the pole piece disposed at the other end are asymmetrical, and
the pole pieces disposed at both ends of the anode cylinder in the tube axis direction include protruding flat surfaces, and a diameter of the protruding flat surface of the pole piece disposed at one end of input side is larger than a diameter of the protruding flat surface of the pole piece disposed at the other end of output side,
wherein a height (HS) of the large and small strap rings in the tube axis direction, a width (WS) of the large and small strap rings in the radial direction, a height (HV) of the vanes in the tube axis direction, a width (WV) of the vanes in the radial-direction, a thickness (TV) of the vanes, and a distance (GV) between free ends of adjoining vanes satisfy the following conditional expressions (1) to (4):
7.8≦HV≦8.2, in millimeters, (1)
0.1≦HS/HV≦0.19;
(2)
0.06≦WS/WV≦0.09;
(3)
GV/(GV+TV)≦0.375. (4)

15 more elements

Dependencies are inferred from the claim text.

Description7,570 words

Summary1,501 words

#The present invention relates to a magnetron, and is suitably applied to a continuous wave magnetron used in microwave heating equipment such as microwave ovens.

#As shown in FIG. 14, a conventional anode structure 100 of a typical magnetron, such as those for microwave ovens, which oscillates to generate 2,450 MHz-band microwaves, includes an anode cylinder 101; and vanes 102, which are radially disposed inside the anode cylinder 101.

#The vanes 102 are connected together through a pair of large and small strap rings 103, which each are brazed to both upper and lower ends of every other vane 102 in the circumferential direction.

Brief description of the drawings14 figures

#FIG. 1 is a longitudinal cross-sectional view of an entire magnetron according to one embodiment of the present invention.

#FIG. 2 is a longitudinal cross-sectional view of major portions of a magnetron according to one embodiment of the present invention.

#FIG. 3 is a lateral cross-sectional view of major portions of a magnetron according to one embodiment of the present invention.

Detailed description5,708 words

#One embodiment of a magnetron of the present invention will be described with reference to the accompanying drawings. Incidentally, embodiments described below are given for illustrative purposes only, and the present invention is not limited to these embodiments.

#FIG. 1 is a longitudinal cross-sectional view schematically showing a magnetron 1 according to the present embodiment. The magnetron 1 is a magnetron for microwave ovens that generate a 2,450 MHz-band fundamental wave.

#The magnetron 1 includes, as a main component, an anode structure 2 that generates a 2, 450 MHz-band fundamental wave. Below the anode structure 2, an input unit 4, which supplies power to a cathode 3 located at the center of the anode structure 2, is disposed. Above the anode structure 2, an output unit 5, which leads microwaves generated from the anode structure 2 out of a tube (or magnetron 1), is disposed.

Facts

Application

15/049,925Filed 22 Feb 2016 · continuation

Priority

JP 2013-17805529 Aug 2013

Published

US 2016/0172145 A116 Jun 2016

Granted

26 Dec 2017

Term ends

27 Aug 2034

Estimated · how

20 years from earliest known nonprovisional domestic filing plus recorded patent term adjustment. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination.

Classification7 codes

H01J 25/52
Magnetrons, i.e. tubes with a magnet system producing an H-field crossing the E-field: with an electron space having a shape that does not prevent…
H01J 23/04
Electrodes; Magnetic control means; Screens: cathodes
H01J 23/10
Electrodes; Magnetic control means; Screens: magnet systems for directing or deflecting the discharge along a desired path, e.g. a spiral path
H01J 23/213
Cavity resonators; Adjustment or tuning thereof: simultaneous tuning of more than one resonator, e.g. resonant cavities of a magnetron

Timeline

29 Aug 2013Priority claimedJP 2013-178055
22 Feb 2016Application filedUS 15/049,925
24 Feb 2016Assigned to Toshiba Hokuto Electronics Corporationassignment of assignor's interest
16 Jun 2016PublishedUS 2016/0172145 A1
26 Dec 2017GrantedUS 9,852,872 B2
12 Oct 2026TodayWithin its term
27 Aug 2034Term endsEstimated

Magnetron

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Magnetron

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims12

Description7,570 words

Drawings

Classification7 codes

Life of this patent

Description7,570 words