KR930000384B1 - Outlet structure of magnetron - Google Patents

Abstract

The structure of the output side comprises the first magnetic pole piece (6) arranged at the opening part of output side, a cylindrical first metal pipe (18) sealed from projected anode, a ceramic insulating pipe (19) connected to the metal pipe (18), a conductor (24) for leading out the microwave, a first cylinder (20) for harmonic choke, a second cylinder (21) for harmonic choke of inverse U-shape. The structure has the cylinder (33a) with λ/4 of the first harmonic wave (λ), the second metal pipe (33) formed with λ'/2 slot (33c) of the second harmonic wave (λ'), a third metal pipe (34) with λ"/4 cylinder (34a) of the third harmonic wave (λ").

Description

Magnetron Output Sphere

1 is a sectional view schematically showing a sphere of the output portion of a conventional magnetron.

2 is a sectional view schematically showing the sphere of the output portion of the magnetron according to the present invention.

3 is a schematic perspective view of (a) and (b) of the second and third metal tubes.

* Explanation of symbols for main parts of the drawings

1: anode cylinder 2: anode vane

5: 2nd magnetic pole piece 6: 1st magnetic pole piece

8 output unit 9 electronic working space

10 cathode cathode filament 18 first metal tube

19: insulated tube 20: first cylinder for harmonic choke

21: Second cylinder for harmonic choke 23: Output antenna cap

24: conductor for microwave extraction 33: second metal tube

33a: cylindrical portion 33b: flange portion

33c: slot 33d: ceiling

34: 3rd metal tube 34a: cylindrical part

34b: flange

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetron for use in a microwave oven, and more particularly to a magnetron output section capable of suppressing leakage of harmonic components of integral multiples of unnecessary fundamental waves originating from the magnetron.

In general, since the magnetron generates microwaves efficiently, it is particularly widely assembled in microwave ovens and the like for heating foods, so that stability, high quality, and long life are strongly desired.

In general, magnetrons are widely used in microwave ovens and the like. However, in the conventional magnetron, an output pipe is fixed to an insulated pipe made of ceramic, and the exhaust pipe is connected to a distal end of a conductor for inducing microwaves. In this case, the depth of the exhaust pipe is set to [lambda] / 4 of the wavelength [lambda] of the second harmonic and used as the choke for suppressing the second harmonic. There is also a magnetron in which a metal cylinder is attached in the middle of the microwave-derived conductor to form a choke for suppressing the third or fourth harmonics.

However, in the magnetron as described above, the internal structure is complicated, and because the metal cylinder is fixed in the middle of the microwave-derived conductor, it is mechanically unstable and the exhaust pipe of the choke may cause harmonic discharge between other components.

By the way, the magnetron of the structure which suppresses radiation of the harmonic component of wavelength (lambda) by forming the (lambda) / 4 wave type choke at the output part in order to suppress generation | occurrence | production of a harmonic in the output part of a magnetron conventionally is known For example, Japanese Unexamined Patent Application Publication No. 62-17973 is disclosed.

As shown in FIG. 1, the magnetron has a plurality of anode vanes 2 radially attached to the inner wall of the anode cylinder 1, and connected to each other by a plurality of strap rings 3 to connect the anode 4 to each other. To form. Both opening ends of the anode cylinder 1 serve as a part of an airtight wall, and at the same time have a generally conical shape having through holes 6a in the center to form a uniform axial magnetic field in the electronic working space 9. The magnetic pole pieces 6 and 5 are fixed, and the negative electrode system which is not shown in the one magnetic pole piece 5 protrudes, and the output part 8 protrudes in the other magnetic pole piece 6, respectively. In addition, cathode filaments 10 are disposed in the electromotive empathy 9 along the axis of the anode 4, and end hats 11 and 12 are fixed to both ends of the cathode filament 10, respectively. have. One end hat 11 is supported by a cylindrical outer cathode support 13 having a feed line, and the other end hat 12 is provided with an inner side of the cathode filament 10 and the outer cathode support 13. It is supported by the inner cathode support 14 which has the feed line which penetrates.

On the other hand, the output part 8 protrudes from the pole piece 6, and this output part 8 is a metal tube 18 hermetically bonded to the anode 4, and a ceramic hermetically bonded to the metal tube 18. Insulation tube 19, the first cylinder 20 for harmonic chokes, the second cylinder 21 for other harmonic chokes, the connection block 22 of the conductor for derivation of microwaves described later, and the output antenna cap 23 ) And a microwave-derived conductor 24. In this case, one end of the microwave-derived conductor 24 is fixed to one of the anode vanes 2, and the other end extending through the inner side of the metal tube 18 and the insulated tube 19 is connected to the connection block 22. Stuck in Then, on the outer side near the distal end portion of the microwave-derived conductor 24, a cylindrical cylindrical choke cylinder 20 having a lid is disposed and fixed to the connection block 22, and the first cylinder 20 and the first cylinder 20 are disposed. A part of the two-cylinder 21 forms a specific harmonic, for example, a second harmonic suppression choke groove 25 outside the tip end of the microwave-derived conductor 24.

However, in the structure of the output structure of the magnetron configured as described above, the harmonic components radiated to the outside of the magnetron cannot be sufficiently shielded among the microwave outputs including the harmonic components corresponding to the fundamental wave of 2450 MHz and the integral multiple of the fundamental wave. Harmonic components have problems such as television, radio, and radio interference.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a magnetron capable of attenuating a plurality of kinds of harmonic components leaking out of a tube while maintaining the size of a conventional magnetron.

In order to achieve the above object, the output structure of the magnetron of the present invention includes a first magnetic pole piece disposed at the output side opening end of the anode cylinder, and a cylindrical member disposed on the upper portion of the magnetic pole piece and protruding from the anode cylinder to be airtight. The metal tube of 1, the ceramic insulated tube hermetically bonded to this 1st metal tube, the microwave-conducting conductor extended through the inside of the said 1st metal tube and the insulated tube from the vane of the said anode, and this microwave derivation The first cylinder 20 for high frequency choke, which is electrically coupled to the distal end of the conductor and coaxially surrounds the distal end of the microwave conducting conductor, is hermetically joined to the outside of the first cylinder. The second cylinder for the high frequency choke, which is generally inverted U-shaped in cross section, which is excreted in accumulation and whose outer cylindrical end is hermetically bonded to the insulator tube, In the structure of the output portion of the magnetron, a through hole 33e which is disposed inside the first metal tube and penetrates the microwave-derived conductor in a non-contact manner is formed, and unnecessary first and second specific high frequency components are removed. The length L1 has a cylindrical portion 33a whose length L1 is λ / 4 of the first specific high frequency wavelength λ so that the length L1 is the second specific high frequency wavelength λ 'at the ceiling 33d. The length L2 is disposed inside the second metal tube 33 and the second metal 33 in which the slot 33c of λ '/ 2 is formed to attenuate the third specific harmonic. It is characterized by consisting of the third metal tube 34 having a cylindrical portion 34a of λ ″ / 4 of the third specific harmonic wavelength λ ″.

In this way, the second and third metal tubes are disposed in the first metal tube to form a microwave output transmission line, and the first to third plurality of harmonics can be attenuated simultaneously. In addition, a slot having a length of λ '/ 2 of the second specific harmonic wavelength λ' is formed on the surface where the through hole through which the microwave-derived conductor of the second metal pipe passes is formed, and the chip is choked by a change in load impedance. By forming the length, unnecessary harmonic components can be suppressed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in describing the embodiment of the present invention, the same reference numerals are given to the same parts as those shown in FIG.

2 is a partially broken cross-sectional view of a magnetron in which a plurality of kinds of metal tubes are disposed in the metal tube according to the present invention, and FIG. 3 is a perspective view showing the second and third metal tubes in FIG. 2.

2 and 3, (1) is an anode cylinder, in which a plurality of anode vanes (2) projecting toward the cathode filament (10) and forming a resonance cavity are arranged, and the anode cylinder (1). The first and second magnetic pole pieces 6 and 5 for magnetic field convergence are arranged opposite to each other at the open ends of the < RTI ID = 0.0 > Then, the first cylinder 20 for harmonic choke and the second cylinder 21 for harmonic choke are placed on the outer edge of the first metal tube 18 by placing an insulating tube 19 made of ceramic. Further, the flange portion 18a of the first metal tube 18 is hermetically sealed to one opening end of the anode cylinder 1 in a state of hermetically covering the first pole piece 6. Here, in the first metal tube 18, the second metal tube 33 and the third metal tube 34 are fixed as shown in FIG.

In the second metal tube 33, a flange portion 33b extends substantially at right angles to one side (the lower side in FIG. 3 (a)) toward the outside, and the ceiling portion 33d has a conductor for microwave guidance 24d. A slot 33c having a length l1 of λ '/ 2 of the wavelength λ' of the second specific harmonic is formed to attenuate the through hole 33e through which the second harmonic passes and the cylindrical portion 33a. ) Has a length L1 corresponding to λ / 4 of the first specific harmonic wavelength λ to attenuate the first specific harmonic.

In addition, in the third metal tube 34, as shown in FIG. 3 (b), the flange portion 34b extends at a right angle to the outside at a substantially right angle, and the ceiling 34d has a conductor for extracting microwaves (34d). A through hole 34e through which 24 passes is formed, and one end of the cylindrical portion 34a having a length L2 of λ ″ / 4 of the third specific harmonic wavelength λ ″ is flanged 34b. It is formed integrally with. In other words, these second and third metal pipes 33 and 34 are punched out by a metal plate to press through holes 33e and 34e, slots 33c, flange portions 33b and 34b, and ceiling parts. 33d and 34d are integrally formed. Moreover, these 2nd and 3rd metal pipes 33 and 34 are fixed by welding between the 1st metal pipe 18 and the 1st pole piece 6 by the flange parts 33b and 34b, respectively. Space formed by the cylindrical portion of the first metal tube 18, the cylindrical portion 33a and the flange portion 33b of the second metal tube 33, that is, the first choke means 40 and the second. To attenuate a plurality of kinds of harmonics by the space formed by the cylindrical portion 33a of the metal tube 33 and the cylindrical portion 34a of the third metal tube 34, that is, the second choke means 41. (Specifically, the length (L1) is set so that the first choke means 40 attenuates harmonics lower than the second choke means 41.)

In addition, the microwave-conducting conductors 24 derived from the anode vanes 2 connect the first magnetic pole pieces 6, the first to third metal plates 18, 33, 34, and the insulating tube 19. It penetrates and is connected to the 1st cylinder 20 for harmonic chokes.

On the first cylinder 20 for harmonic choke, a cup-shaped metal output antenna cap 23 is fixed, and on the other opening end of the anode cylinder 1, a second pole piece 5 is provided. It is sealed, and the flange part 26a of the metal pipe 26 is hermetically sealed under the 2nd pole piece 5 below.

In this configuration, the line resonance filter is formed by the first metal tube 18 in the slot 33c formed in the second metal tube 33, and the length l1 of the slot 33c is determined by the second specification. The second specific harmonic can be attenuated by configuring the line resonance type filter means by configuring λ '/ 2 of the harmonic wavelength λ'. In addition, since the coupling of the filter is strengthened by the third metal tube 34, there is an excellent effect of attenuating a larger amount of the third specific harmonic component, that is, the noise, and the second metal tube 33 and the third. The lengths L1 and L2 of the cylindrical portions 33a and 34a of the metal tube 34 of the metal tube 34 have a length of λ / 4 and λ ″ / 4 of the first and third specific harmonic wavelengths λ, λ ″. Since the transmission line is constituted by the microwave-derived conductor 24 and the first metal tube 18, most of the plurality of types of the first and second specific harmonic components radiated from the microwave-derived conductor 24 are The cathode filament side is reflected and reduced to heat to attenuate the amount of radiation emitted outside the tube of the harmonic magnetron.

As described above, according to the present invention, the first choke means constituted by the cylindrical force of the first metal tube and the cylindrical wall of the second metal tube, and the second constituted by the second metal tube and the third metal tube. By filtering the noise by plural kinds of harmonic components other than the fundamental wave by the choke means, the amount of harmonic components leaking out of the magnetron tube can be further attenuated, and the second and third metal tubes can be placed in the first metal tube. Since it is excreted, compared with the conventional magnetron, it has the outstanding effect of being able to attenuate a plurality of kinds of harmonic components, without increasing size.

Claims (3)

A first magnetic pole piece 6 disposed at an output end of the anode cylinder, a cylindrical first metal tube 18 disposed above the pole piece 6 and protruding from the anode cylinder and airtightly disposed; A ceramic insulating tube 19 hermetically bonded to the first metal tube 18, the first metal tube 18 and the insulating tube 19 from the positive electrode vane 2, and the positive electrode vane The microwave guide conductor 24 extending from the inside of the first metal tube 18 and the insulated tube 19 from (2) and the tip of the microwave guide conductor 24 are electrically coupled to the first guide tube 24. The first cylinder 20 for high frequency choke, which is disposed by coaxially surrounding the distal end of the microwave-derived conductor 24, is hermetically bonded to the outside of the first cylinder 20, and is coaxially disposed. U-shaped cross section whose outer cylindrical end is hermetically bonded to the insulated tube 19 is generally inverted U-shaped In the output sphere of the magnetron made of the second cylindrical cylinder 21 for merchant high frequency choke, a through-hole 33e is formed inside the first metal tube and provides a non-contact through-hole of the microwave-leading conductor 24. At the same time, the length L1 has a cylindrical portion 33a whose length L1 is λ / 4 of the first specific harmonic wavelength λ so as to attenuate unnecessary specific harmonic components. [Lambda] '/ 2 of the second specific harmonic wavelength [lambda]' is disposed inside the second metal tube 33 formed in the slot 33c and the second metal tube 33, and the third specified. The output portion of the magnetron, characterized in that it consists of a third metal tube 34 having a cylindrical portion 34a having a length L2 of λ ″ / 4 of a third specific harmonic wavelength λ ″ to attenuate harmonics. rescue. The magnetron of claim 1, wherein the second metal pipe (33) constitutes a line resonance filter means by a slot (33c) formed in the ceiling (33d) and the first metal pipe (18). Output structure. 2. The second metal tube (33) according to claim 1, wherein the second metal tube (33) constitutes a first choke means by a cylindrical portion (33a) and a flange portion (33b) and a cylindrical portion of the first metal tube (18). The third metal tube 34 constitutes the second choke means by the cylindrical portion 34a and the flange portion 34b and the cylindrical portion 33a of the second metal tube 33, and the first choke. And the means attenuates harmonic components lower than the second choke means.

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