KR19980034711A - Magnetron vane - Google Patents

Abstract

The present invention relates to a vane of a magnetron, wherein the horizontal cross-sectional shape of the vane is formed to have a wedge shape from the anode body to the cathode side, so that the capacitance component (C) in the working space is increased, and the inductance component (L) corresponding to the increase amount. Even if it is reduced, the same resonant frequency can be obtained, it is possible to reduce the design of the anode body to reduce the volume and at the same time reduce the manufacturing cost, it is to be able to quickly heat transfer the heat generated from the cathode.

Description

Magnetron vane

The present invention relates to a magnetron generating microwaves, and more particularly, to a vane of a magnetron suitable for changing a resonator frequency existing between vanes by changing a capacitance value of the magnetron.

In general, the magnetron generates ultra-high frequency by high voltage supplied from the outside, and it is 915MHz used in the magnetron generating high frequency of 2450MHz used for medical, microwave, and other heating, industrial heating range, continuous wave radar. The magnetron generates a high frequency of the present invention, the present invention relates to a magnetron used in a microwave oven.

On the other hand, Figure 1 is a cross-sectional view showing the structure of a conventional conventional magnetron.

As can be seen from the drawing, a plurality of (generally even) vanes 8 forming a cavity resonator to induce high frequency components are formed inside the anode body 6 formed in a cylindrical shape by a copper pipe or the like. It is arrange | positioned at equal intervals toward an axial direction, and an anode part is comprised by such an anode body 6 and the vane 8.

In order to change the capacitance to obtain a uniform resonant frequency, inner and outer equalization rings 8a and 8b are alternately connected to the vanes 8 at upper and lower ends thereof, respectively, on the tip end side of the vanes 8, respectively. On the central axis of the body 6, the working space 10 is formed between the front end portions of the plurality of vanes 8 and the filament 12.

In addition, in the working space 10, a filament 12 formed of a mixture of tungsten (W) and thorium oxide (ThO ₂ ) and wound in a spiral shape is disposed coaxially with the anode body 6. 12 is heated by an operating current provided from the outside to emit hot electrons.

On the other hand, the upper and lower shield hats 14 and 16 are fixed to both ends of the filament 12 to prevent radiated hot electrons from radiating in the central axis direction, and the lower shield hat 16 is made of molybdenum. The first filament electrode 20, which is a central support of the welding, is welded to the lower end of the upper shield hat 14 through a through hole formed in the center thereof, and a second filament electrode made of molybdenum is formed on the bottom surface of the lower shield hat 16. 22) is welded.

Here, the first and second external filament electrodes 20 and 22 are connected to the power supply terminals 28 and 30 through through holes formed in the insulating ceramic 18 for holding the cathode of the magnetron. A cathode support is electrically connected to the connection terminals 24 and 26 to supply current to the filament 12. The first filament electrode 20 supports the upper shield hat 14 while passing through the central axis of the filament 12. do.

In addition, the upper and lower pole pieces 32 and 34 for forming a magnetic path are formed on both sides of the anode body 6 so as to uniformly form the magnetic flux in the working space 10 between the filament 12 and the vane 8. While fixed, these upper and lower pole pieces 32, 34 are funnel-shaped magnetic bodies.

Upper and lower shield cups 36 and 38 are sealed and welded to upper and lower portions of the upper and lower pole pieces 32 and 34, respectively, and an anode body is disposed on upper and lower portions of the upper and lower shield cups 36 and 38, respectively. In order to seal the inside of 6) in a vacuum state, the antenna ceramic 40 and the insulating ceramic 18 are brought into close contact with each other and welded together.

In addition, a cylindrical antenna ceramic 40 for insulating the antenna cap 42 described later is joined to the upper opening end of the upper shield cup 36 constituting the output portion of the magnetron, and an upper end portion of the antenna ceramic 40 is joined. The exhaust pipe 44, which is a copper material, is joined to the inner central portion of the exhaust pipe 44, and an antenna 46 is provided to output a high frequency oscillated in the cavity resonator, and the antenna 46 has a vane 8 Derived from, it is penetrated through the central portion of the upper pole piece 32 and extends axially, the end is fixed in the exhaust pipe (44).

In addition, the outer surface of the exhaust pipe 44 protects the welded portion of the exhaust pipe 44, prevents sparks generated by electric field concentration, serves as a high frequency antenna, and serves as a window for outputting high frequency to the outside. An antenna ceramic 40 and an antenna cap 42 are covered.

The operation process of the magnetron made of the above-described members is as follows.

First, when an external power source is provided to the first and second external connection terminals 24 and 26 through the power terminals 28 and 30, the first external connection terminal 24, the first filament electrode 20, and the upper shield are provided. A closed circuit composed of the hat 14, the filament 12, the lower shield hat 16, the second filament electrode 22, and the second external connection terminal 26 is configured to supply an operating current to the filament 12.

Then, the filament 12 is heated by the operating current provided to the filament 12 to emit hot electrons from the filament 12, thereby forming an electron group by the released hot electrons.

At this time, in the working space 10 between the filament 12 and the vane 8 by the driving voltage applied to the second filament electrode 22 and the anode portion (that is, the anode body 6 and the vane 8). A strong electric field is formed, and the magnetic field generated by the magnet A (2) and the magnet K (4) is guided toward the working space (10) along the lower pole blood number (34) and through the working space (10), the upper pole pole piece ( Proceeding to 32, a high magnetic field is formed in the working space 10.

Therefore, the electron group formed by the hot electrons emitted from the filament 12 into the working space 10 is formed by the strong electric field and the high magnetic field formed in the working space 10, and thus the anode portion (the anode body 6 and the vane 8). It proceeds in a spiral rotational motion in the direction, this movement of the electron group is made in all the space of the working space (10).

Accordingly, as the electron group formed of the hot electrons repeatedly moves toward the anode portion (the anode body 6 and the vane 8) according to the structural resonance circuit of the vane 8 and the cavity resonator, the electron group rotates. A high frequency of 2450 MHz, which is a resonance frequency corresponding to the speed, is induced from the vane 8.

Then, the high frequency (2450 MHz) induced from the vane 8 is transmitted to the exhaust pipe 44 through the antenna 46, provided to the microwave through a wave guide, and then through the dispersion apparatus. The food is cooked by the frictional heat generated when the food molecules in the cavity vibrate about 2.4 billion times per second.

On the other hand, as shown in Fig. 2, inside the cylindrical anode body 6, a plurality of (generally even) vanes 18 are formed at equal intervals in the axial direction and have a structure with a cavity resonator. As the electron group formed of the hot electrons is repeatedly moved in the direction of the anode part (the anode body 6 and the vane 18) according to the conventional resonance circuit, a high frequency of 2450 MHz, which is a resonance frequency corresponding to the speed at which the electron group rotates, From the vanes 18.

At this time, the electron group causes the vane 18 to interfere with the vane 18 at a period equal to the reciprocal of the multiple of the periodic microwave oscillation frequency, and the space between the vanes 18 by this action, that is, the cavity In the resonator, a capacitance component having a predetermined capacitance and an inductance component on a circuit composed of an anode body 6 connecting the same constitute a parallel resonance circuit, and the resonance frequency according to the structure of the vane 18 is It is determined to generate a constant microwave.

From here, As shown in FIG. 3, ε ₀ is the dielectric constant in vacuum, d is the distance between the vanes 18, and A is the cross-sectional area of the vanes 18, respectively.

On the other hand, in order to increase the magnetron output, the number of vanes 18 should be increased or the thickness of the vanes 18 should be thickened to increase the current flowing into the vanes 18.

However, by increasing the number of vanes 18 or by increasing the thickness of the vanes 18, the separation distance between the vanes 18 in the working space 10 is reduced, so that the oscillation mode is not broken or the oscillation does not occur. have.

Accordingly, the present invention has been made in view of the above-described problems of the prior art, and has a predetermined separation distance between vanes in the working space, and forms a cross-sectional shape of the vanes so as to have a wedge shape from the anode body to change the capacitance. The purpose is to provide vanes of magnetrons.

In order to achieve the above object, the present invention, in the magnetron for generating a microwave by the hot electrons generated from the cathode, the vane of the magnetron, characterized in that the horizontal cross-sectional shape of the vane is formed to have a wedge shape from the anode body toward the cathode side To provide.

1 is a cross-sectional view showing the structure of a typical magnetron

FIG. 2 is a horizontal cross-sectional view taken along line AA of FIG. 1, illustrating vanes of a conventional magnetron. FIG.

3 is a partially cutaway perspective view of the vane of the magnetron shown in FIG.

4 is a cross-sectional view taken along line AA of FIG. 1, illustrating vanes of the magnetron according to an exemplary embodiment of the present invention.

5 is a partially cutaway perspective view of the vane of the magnetron shown in FIG.

* Description of the symbols for the main parts of the drawings *

2: Magnet A4: Magnet K

6: bipolar body 8, 18, 28: vane

10: working space 12: filament

14, 16: shield hat 18: insulating ceramic

20, 22: filament electrode 24, 26: external connection terminal

28, 30: power end 32, 34: pole piece

36, 38: shield cup 40: antenna ceramic

42: antenna cap 44: exhaust pipe

46: antenna

The above and other objects and various advantages of the present invention will become more apparent through the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a cross-sectional view taken along line AA of FIG. 1 and illustrates vanes of the magnetron according to an exemplary embodiment of the present invention.

As can be seen by comparing the shape of the vanes 18 in FIG. 2 showing the vanes of the conventional conventional magnetron and the vanes 28 in FIG. 4 showing the vanes of the magnetron according to the present invention, The horizontal cross-sectional shape of the vanes 28 according to the present invention is formed in a wedge shape from the anode body 6 to the cathode side.

The operation of the vanes of the magnetron according to the present invention formed as described above will be described in more detail with reference to FIGS. 1, 4, and 5.

First, when an external power source is provided to the first and second external connection terminals 24 and 26 through the power terminals 28 and 30, the first external connection terminal 24, the first filament electrode 20, and the upper shield are provided. A closed circuit composed of the hat 14, the filament 12, the lower shield hat 16, the second filament electrode 22, and the second external connection terminal 26 is configured to supply an operating current to the filament 12.

Then, the filament 12 is heated by the operating current provided to the filament 12 to emit hot electrons from the filament 12, thereby forming an electron group by the released hot electrons.

At this time, in the working space 10 between the filament 12 and the vanes 28 by the driving voltage applied to the second filament electrode 22 and the anode portion (that is, the anode body 6 and the vanes 28). A strong electric field is formed, and the magnetic field generated by the magnet A 2 and the magnet K 4 is guided along the lower pole piece 34 toward the working space 10 and the upper pole piece through the working space 10. Proceeding to 32, a high magnetic field is formed in the working space 10.

Therefore, the electron group formed by the hot electrons emitted from the filament 12 into the working space 10 is formed by the strong electric field and the high magnetic field formed in the working space 10 (the anode body 6 and the vanes 28). It proceeds in a spiral rotational motion in the direction, this movement of the electron group is made in all the space of the working space (10).

At this time, the electron group causes the vane 28 to interfere with the vane 28 at intervals equal to the reciprocal of the multiple of the periodic microwave oscillation frequency, and by this action, the space facing the vanes 28, that is, the resonator The parallel resonant circuit is constituted by a capacitance component having a predetermined capacitance and an inductance component on a circuit composed of the anode body 6 which connects the capacitance component.

As can be seen with reference to Figures 4 and 5, Therefore, the resonance frequency The frequency of the microwave is changed accordingly.

Here, epsilon ₀ is the dielectric constant in vacuum, d 'is the distance between vanes 28, and A' is the cross-sectional area of the vanes 28, respectively.

At this time, as shown in Figure 4, since the horizontal cross-sectional shape of the vanes 28 is shaped to have a wedge shape from the anode body 6 to the cathode side, the separation distance of the vanes 28 is d '.

Therefore, since the separation distance between the vanes 28 is shortened, the capacitance component C is increased, and even if the inductance component L is reduced in correspondence with the increase amount of the capacitance component C, the same resonance frequency can be obtained. .

That is, in the resonator, since the inductance component L correlates with the length of the anode body 6, the same resonant frequency is generated even if the inductance component L is reduced in accordance with the increase amount of the capacitance component C. It will be readily appreciated that the anode body 6 can be reduced.

As described above, according to the present invention, the horizontal cross-sectional shape of the vanes 28 is formed to have a wedge shape from the anode body 6 to the cathode side, so that the capacitance component C in the working space 10 is increased. Even if the inductance component (L) is reduced in accordance with the increase amount, the same resonance frequency can be obtained. Therefore, the reduced design of the anode body 6 can be achieved, thereby reducing the volume and reducing the manufacturing cost of the anode body. There is an effect that can quickly heat transfer the heat.

Claims (1)

In a magnetron that generates microwaves by hot electrons generated from a cathode, The vane of the magnetron, characterized in that the horizontal cross-sectional shape of the vane is formed to have a wedge shape from the anode body toward the cathode side.