KR0136191Y1 - Cathode support structure of magnetron - Google Patents

Abstract

The present invention relates to a cathode support of a magnetron, comprising: a filament for emitting hot electrons, upper and lower end hats fixedly attached to both ends of the filament, and an anode body for forming a resonant cavity near the center of the filament. And a magnetic pole piece for forming a magnetic path in the anode cylinder, a metal plate for sealing the inside of the anode cylinder with a vacuum, an exhaust pipe disposed on an upper portion of the ceramic pipe disposed in the metal pipe on the output side, and oscillated in the resonance cavity. An antenna for outputting a high frequency, a second lead wire having one end portion fixed to the upper end hat by penetrating the lower end hat and the filament in a non-contact manner, and the lower end hat being disposed at a predetermined distance from the second lead wire First and second external wires electrically connected to first lead wires supporting the first and second lead wires, respectively; In a magnetron having a fast terminal, a first through hole 32a through which the first lead wire 27 penetrates is formed, and a first conductive terminal 32 fixed to the first external connection terminal 30. ), A through hole 34a through which the second lead wire 35 penetrates, and a second conductive terminal 34 fixed to the second external connection terminal 31; And fixing holes 39 and 42 in which the second lead wires 27 and 35 are inserted and fixed through the through holes 32a and 34a, and the first and second conductive terminals 32 ( The recessed grooves 40 formed between the fixing holes 39 and 42 and the first and second external connection terminals 30 and 31 are formed so as to facilitate separate installation of the 34 and prevent electrical connection. And a through-hole having a through hole, wherein the first and second conductive terminals 32 and 34 are formed on the upper surface of the insulating ceramic 41 to be fixed through a molybdenum-manganese paste layer. In this way, the expensive molybdenum lead wire can be shortened to reduce the manufacturing cost and to improve the shock resistance of the negative electrode portion, and to have the same shape on the upper surface of the insulating ceramic. The conductive terminals are arranged to face each other, so that the through-holes in which the first and second external connection terminals are inserted can be hermetically sealed, thereby suppressing the formation of air gaps in the magnetron and maintaining the inside of the magnetron at a high vacuum. In addition to stabilizing the efficiency and output of the present invention, it is possible to extend the service life compared to the conventional products, and to reduce the manufacturing cost due to the simple manufacturing process.

Description

Magnetron Support Structure

1 is a partially broken cross-sectional view of a cathode structure in a conventional magnetron.

2 is a partial cross-sectional view of the magnetron cathode support structure according to an embodiment of the present invention.

3 is an enlarged cross-sectional view of the cathode of FIG.

4A is an enlarged cross-sectional view of a portion B of FIG.

Figure 4b is an enlarged perspective view of a conductive terminal applied to an embodiment of the present invention.

5 is a cross-sectional view of the negative electrode support structure in the magnetron showing another embodiment of the present invention.

FIG. 6A is an enlarged cross-sectional view of part C of FIG.

Figure 6b is an enlarged perspective view of a conductive terminal applied to another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

1: filament 2: top end hat

3: Lower end hat 4,5: Lead wire

6,18 metal tube 7: insulator

8,9: terminal piece 17: antenna

19: annular concave groove 27: first lead wire

30: first external connection terminal 31: second external connection terminal

32,62: 1st challenge terminal 34,64: 2nd challenge terminal

35: 2nd lead wire 39, 42: fixing hole

40: concave groove 41: insulating ceramic

The present invention relates to a magnetron used in a microwave heating device such as a microwave oven, and relates to a cathode support structure of a magnetron which is an improvement of a cathode support structure of a magnetron.

1 is a sectional view schematically showing a cathode structure of a conventional magnetron. In the same figure, reference numeral 1 denotes a helical filament made of thorium and tungsten, and a pair of molybdenum end hats 2 and 3 are fixed to both ends thereof, and the upper end hat 2 has a filament 1 attached thereto. ), And the lead wire 5 of the molybdenum material which penetrates in a non-contact manner is fixed, and the lead wire 4 of the same material as the lead wire 5 which supports the filament 1 is fixed to the lower end hat 3. The other ends of these lead wires 4 and 5 penetrate through the through-holes formed in the insulator 7 which is the cathode support structure of the magnetron, and are brazed to the terminal pieces 8 and 9. In other words, the lower ends of the lead wires 4 and 5 are welded to the metal layer 7B deposited on the outer surface of the insulator 7 made of ceramic material and brazed to the terminal pieces 8 and 9. In addition, a metal layer is deposited on the outer circumferential portion 7D of the opening of the insulator 7, and the metal tube 6 is hermetically welded and fixed to the outer circumferential portion 7D, and the flange portion 6a of the metal tube 6 is fixed. Although not shown above, the pole pieces and the anode body are hermetically welded.

However, in the magnetron structure of the magnetron thus constructed, as shown in FIG. 1, the length from the sealing position of the pair of lead wires 4 and 5 penetrating through the insulator 7 to the upper end hat 2 of the cathode portion is shown. Since (A) is long, the length of the lead wire made of expensive molybdenum material is long, so that the manufacturing cost is high, and in case of an impact from the outside, the amplitude of vibration generated at the leading end of the lead wire, i.e., the upper end hat 2, is large. Filaments susceptible to vibration, i.e., the cathode, are easily damaged, and the lead wires 4 and 5 are inserted through the through holes 10 and 10 formed in the insulator 7 to be electrically connected to the metal layers 7B and 7B. When the lead wires (4) and (5) are significantly thinner than the through holes (10) and (10) of the insulator (7), they are electrically connected but not partially contacted. By on Since a gap (air gap) animation, there is a fear of air is introduced through the through-hole of the insulator (7) there are many problems in that the degree of vacuum is destroyed in the magnetron.

In addition, in the cathode support structure of the magnetron configured as described above, when the center of the cathode, i.e., the filament (1), which is a thorium-tungsten alloy material, is out of the center of the anode body (not shown), the filament (1) and the anode vane contribute to the oscillation to the adjacent site. Each cavity resonator that the anode vanes are formed by concentrating the hot electrons in the vicinity of the anode vanes due to the non-uniform distribution of hot electrons generated in the filament (1) due to the increase in leakage current, which is a loss current, which cannot be obtained. The non-uniform electrical energy is applied to not only the microwave output is lowered, but also the temperature of the filament 1 in the portion where the hot electrons are concentrated rapidly rises locally, thereby rapidly evaporating the thorium inside the filament 1 necessary for hot electron radiation. The heat electron emission ability of the filament (1) is drastically lowered, There were problems that were rapidly reduced problems occur.

Therefore, the present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a magnetron negative electrode support structure which can shorten expensive molybdenum lead wire and reduce manufacturing cost and improve the shock resistance of the negative electrode portion. To provide.

Another object of the present invention is to improve the efficiency and output of the magnetron, and to provide a cathode support structure of the magnetron having a long life.

It is still another object of the present invention to provide a magnetron support structure of a magnetron capable of hermetically sealing a through hole of a lead wire formed in an insulator to prevent the formation of an air gap in the magnetron.

In order to achieve the above object, the cathode support structure of the magnetron according to the present invention includes a filament for emitting hot electrons, upper and lower end hats fixedly disposed at both ends of the filament, and a resonance cavity near the center surrounding the outside of the filament. A positive electrode body to be formed, a magnetic pole piece for forming a magnetic path inside the positive electrode body, a metal plate for sealing the inside of the positive electrode body with a vacuum, an exhaust pipe disposed at an upper portion of the ceramic tube disposed in the metal tube on the output side, and the resonance An antenna for outputting high frequency oscillated in the cavity, a second lead wire having one end portion fixed to the upper end hat by non-contacting the lower end hat and the filament, and disposed at a predetermined distance from the second lead wire A first lead wire supporting the lower end hat and electrically connected to the first and second lead wires, respectively. A magnetron having first and second external connection terminals, the first conductive terminal having a through hole through which the first lead wire is fixed and fixed to the first external connection terminal, A through hole is formed through which the second lead wire is fixed, and a second conductive terminal is fixed to the second external connection terminal, and the first and second lead wires are fixed through the through hole. A fixing hole, a concave groove formed between the fixing holes to facilitate separation and prevention of electrical connection of the first and second conductive terminals, and a through hole through which the first and second external connection terminals pass. And an insulating ceramic in which the first and second conductive terminals are fixed on the upper surface thereof through a paste layer of molybdenum-manganese.

In this way, a pair of lead wires made of expensive molybdenum, which determines the position of the filament, can be shortened, and the manufacturing cost can be reduced, and a pair of lead wires are short, so that vibration of the vicinity of the filament, that is, the cathode portion Can be prevented, and the seismic resistance is improved, and the air gap can be prevented from being formed in the magnetron by hermetically sealing the through hole of the lead wire formed in the insulating ceramic.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol is attached | subjected about the same part as FIG. 1, and the overlapping description is abbreviate | omitted.

2 is a partial cross-sectional view of the negative electrode support of the magnetron according to an embodiment of the present invention, Figure 3 is a cross-sectional view showing an enlarged negative portion of Figure 2, Figure 4a is an enlarged cross-sectional view of part B of FIG. Figure 4b is an enlarged perspective view of the conductive terminal applied to the present invention.

2 to 4b, reference numeral 12 denotes an anode cylinder formed in a cylindrical shape by, for example, a copper plate or the like, and a plurality of vanes 16 forming a plurality of resonant cavities on the inner surface of the anode cylinder 12. This anode is arranged and the anode portion 12 and the vanes 16 constitute the anode portion. In the vicinity of the central axis of the anode cylinder 12, a working space is formed by the tip portions of the plurality of vanes 16. In the working space, for example, thorium-tungsten or the like is spirally wound to radiate hot electrons. The wound filament 1 is arrange | positioned. The upper and lower end hats 2 and 3 are fixed to both ends of the filament 1 so as to prevent radiation of hot electrons in the direction of the central axis, which is a loss current that does not contribute to oscillation. The first lead wire 27 is welded to the bottom surface, and the second lead wire 35 is welded to the upper end hat 2 through a through hole (not shown) formed near the center of the lower end hat 3. It is stuck. Here, the second lead wire 35 penetrates non-contact with the lower end hat 3 and the filament 1, and these lead wires 27 and 35 are all made of molybdenum material, and thus the filament 1 To supply the operating current.

In the figure, reference numerals 13 and 14 are funnel-shaped pole pieces that are fixed to both openings of the anode cylinder 12 to form a magnetic path uniformly converging the magnetic flux in the working space. The outer edges of both ends remaining after being seated at the cut out position are bent and fixed, and are hermetically welded, and the upper and lower portions of the funnel-shaped magnetic pole pieces 13 and 14 are sealed with a vacuum inside the anode body 12. The metal pipes 18 and 6 for fixing are respectively fixed to the middle of the pole pieces 13 and 14 or the ends of the anode cylinder 12 by welding, respectively, and are fixed to the outer surfaces of the metal pipes 18 and 6, respectively. At a distance, ring-shaped permanent magnets 20 and 21 are disposed, respectively. In addition, an output side ceramic tube 36 formed in a ceramic cylindrical shape is fixedly connected to the upper opening end of the metal tube 18 by welding or the like, and an upper end portion of the output side ceramic tube 36 is made of copper. The exhaust pipe 43 is fixed, and the other side of the antenna 17 having one side coupled to the vane 16 is welded and fixed near the inner central portion of the exhaust pipe 43 so as to output high frequency oscillated in the resonance cavity. The outer surface of the exhaust pipe 43 is covered with an antenna cap 37 that protects the welded portion of the exhaust pipe 43, prevents sparking due to electric field concentration, and acts as a high frequency antenna, and draws high frequency output to the outside. .

In addition, on the outer circumferential surface of the anode cylinder 12, a plurality of aluminum heat sinks 15 extending in the radial direction of the tube are fitted and arranged by a clamp member 24 fixed to a yoke, which will be described later. Together with the permanent magnets 20 and 21, it is covered by the yoke 22a and 22b for forming a porcelain. In addition, a first gasket 29 formed of a metal mesh or the like between the upper side of the permanent magnet 20 on the output side and the opening of the yoke 22a to prevent the leakage of radio waves at a high frequency is formed by the second gasket 38. It is arrange | positioned through.

On the other hand, the lower end portions of the first and second lead wires 27 and 35 are through holes 32a and 34a formed in the first and second conductive terminals 32 and 34, as shown in detail in FIG. 4B. It is inserted into and fixed in the fixing holes 39 and 40 formed in the insulating ceramic 41 and passes through the insulating ceramics in the cap portions 32b and 34b of the first and second conductive terminals 32 and 34. One end of the first and second external connection terminals 30 and 31 inserted into the through hole formed in the 41 is fixed to insert the other end of the first and second external connection terminals 30 and 31. Power is supplied to the negative electrode through a power line not shown, which is connected to the negative electrode. Here, the first and second conductive terminals 32 and 34 are welded to the upper surface of the insulating ceramic 41 so that an air gap is formed in the magnetron so as not to destroy the degree of vacuum. As shown in detail in FIG. 4B, the flat surface 32c is hermetically welded to the upper surface of the insulating ceramic 41 and the first and second lead wires 27 and 35 are formed on the flat surface 32c. Airtightly seals through holes 32a and 34a through which electrical connections are made, and insertion holes of first and second external connection terminals 30 and 31 formed in the insulating ceramic 41. At the same time, one side of the first and second external connection terminals 30 and 31 is composed of caps 32b and 42b inserted therein.

Next, the structure of the insulating ceramic 41, which is the main part of the present invention, and the welding fixing of the first and second conductive terminals 32 and 34 welded to the upper surface of the insulating ceramic 41 will be described. .

As shown in FIGS. 3 and 4a, the insulating ceramic 41 has a cylindrical shape, and the insulating ceramic 41 has a space between the metal tube 6 and the first and second external connection terminals 30 and 31. An annular concave groove 19 formed in two stages at an inner side with a predetermined distance from the outer surface of the insulating ceramic 41 so as to ensure electrical insulation to the first and second external connection terminals 30, 31, that is, a central concave groove 40 having a constant width around the diameter line of the insulating ceramic 41 and a through hole through which the first and second external connection terminals 30 and 31 are inserted. And a center connection line between the first and second external connection terminals 30 and 31 so as to be generally separated by the distance between the first and second external connection terminals 30 and 31. 2 inserts into the fixing holes 39 and 42 formed to insert and fix the two-lead wires 27 and 35, and the through hole and the fixing hole 39 and 42, respectively. First and second conductive terminals 32 on the top surface of the first and second external connection terminals 30 and 31 and the first and second lead wires 27 and 35 to be electrically connected to each other. 34) is welded. Here, the first and second lead wires 27 and 35 have through holes 32a formed in the first and second conductive terminals 32 and 34 to supply power to the filament 1 to radiate hot electrons. The first and second external connection terminals 30 and 31 are inserted into the fixing holes 39 and 42 respectively formed in the upper surface of the insulating ceramic 41 and then welded to each other. Is inserted into the through-hole formed in the lengthwise direction of the insulating ceramic 41, and then the upper end is inserted into and fixed to the cap portions 32b and 34b formed on the first and second conductive terminals 32 and 34, respectively. It is stuck. And around the upper edge of the said insulating ceramic 41, it weld-fixes through the paste layer of molybdenum-manganese agent which is not shown in figure.

Next, another embodiment of the present invention will be described with reference to FIGS. 5 to 6b.

FIG. 5 is a cross-sectional view of the cathode support structure of the magnetron showing another embodiment of the present invention, and FIG. 6A is an enlarged cross-sectional view of part C of FIG.

The embodiment shown in FIGS. 5 through 6b differs from the embodiment shown in FIGS. 2 through 4b in that the cap portions 32b and 34b of the first and second conductive terminals 32 and 34 are different. Without forming the through hole 62a for insertion of the first and second lead wires 27 and 35 into the first and second conductive terminals 62 and 64, as shown in FIG. Only 64a is formed. Therefore, the first and second external connection terminals 30 and 31 are inserted into the through-holes formed in the insulating ceramic 41, and then the first and second conductive terminals (3) are formed on the upper surface of the insulating ceramic 41. 62) and 64 are weld-bonded via a paste layer of molybdenum-manganese agent not shown to be electrically connected. Accordingly, the through-holes for inserting the first and second external connection terminals 30 and 31, such as the first and second conductive terminals 62 and 64, having the same shape as each other described above are hermetically sealed. It can be sealed to keep the inside of the magnetron at high vacuum.

Next, the operation effect of the cathode support structure of the magnetron according to the present invention configured as described above will be described.

When power is applied through the external connection terminals 30 and 31, a closed circuit is formed by the second external connection terminal 30 so that an operating current is supplied to the filament 1 to be heated, and heat electrons from the filament 1. Is emitted. The hot electrons act in the magnetic field of the magnetic pole pieces 13 and 14 to generate high frequency oscillation, and the high frequency output is interposed between the exhaust pipe 43 and the antenna cap 37 through the vanes 16 and the antenna 17. It is radiated into the oven of a microwave oven.

However, the negative electrode support structure of the magnetron according to the present invention has a fixing hole formed in the insulating ceramic 41 in parallel with the first lead wire 27 and the second lead wire 35 supporting the filament 1. 39 and 42, respectively, and the first and second external connection terminals 30 are interposed between the first and second conductive terminals 32 and 34 on the upper surface of the insulating ceramic 41, respectively. 31), the length of the first and second lead wires 27 and 35, which are made of expensive molybdenum, is not required to be bent at two locations near the center of the second lead wire 35. Therefore, the vibration resistance is improved.

Further, the first and second conductive terminals 32 and 34 are fixed to the upper surface of the insulating ceramic 41 via a molybdenum-manganese paste layer, respectively, and then the first conductive terminals 32 ( The first lead wire 27 and the first external connection terminal 30 are electrically connected through 62, and the second lead wire 35 and the second conductive terminal 34 and 64 are electrically connected to each other. The first conductive terminal 32 (the through hole through which the first and second external connection terminals 30 and 31 are inserted) can be electrically connected to the second external connection terminal 31. 62) and the second conductive terminals 34 and 64, the air gaps can be prevented from being formed in the magnetron, and it can be maintained at a high vacuum at all times.

In addition, the recessed groove formed in the intermediate portion of the insulated ceramic facilitates separate installation of the first and second conductive terminals and prevents electrical connection.

As described above, according to the magnetron cathode support structure according to the present invention, the expensive molybdenum lead wire is shortened to reduce the manufacturing cost and to improve the shock resistance of the cathode portion, and also to improve the The first and second conductive terminals of the shape are disposed to face each other, so that the through-holes into which the first and second external connection terminals are inserted can be hermetically closed, thereby suppressing the formation of air gaps in the magnetrons. Since the inside is maintained at a high vacuum, the efficiency and output of the magnetron can be stabilized and at the same time, the service life can be extended as compared with the conventional products, and the manufacturing process is simple and the manufacturing cost can be reduced.

Claims (1)

A filament that emits hot electrons, upper and lower end hats fixedly disposed at both ends of the filament, an anode body for forming a resonant cavity near a center surrounding the outside of the filament, and a magnetic pole forming a magnetic path in the anode body A metal plate for sealing the inside of the anode cylinder with a vacuum, an exhaust pipe disposed on an upper portion of the ceramic pipe disposed on the metal pipe on the output side, an antenna for outputting a high frequency oscillated in the resonance cavity, the lower end hat and A second lead wire having non-contact through the filament and having one end fixed to the upper end hat, a first lead wire disposed at a predetermined distance from the second lead wire to support the lower end hat, and the first And a magnetron having first and second external connection terminals electrically connected to a second lead wire, respectively. A through hole 32a through which a line penetrates is formed, and a first conductive terminal 32 fixed to the first external connection terminal 30 and a second lead wire 35 are fixed through. The second conductive terminal 34 formed with the through hole 34a and fixed to the second external connection terminal 31 and the first and second lead wires 27 and 35 are formed through the through hole ( Fixing holes 39 and 42 which are inserted and secured through 32a and 34a and the fixing holes 39 to facilitate separation and installation of the first and second conductive terminals 32 and 34 and to prevent electrical connection. A concave groove 40 formed between (39) and (42), and a through hole through which the first and second external connection terminals 30 and 31 pass. A cathode support structure for a magnetron, characterized in that the two conductive terminals (32) (34) are made of an insulating ceramic (41) fixed through a paste layer of molybdenum-manganese.