KR20000013684U - Grid Coupled Structure of Low Voltage Driving Microwave Oscillator Tube - Google Patents

Abstract

The present invention relates to a grid coupling structure of a low-voltage driving ultra-high frequency oscillation tube, and attaches a ceramic ring 20 having a step portion 21 formed at an inner circumferential end thereof on an upper portion of the fixed plate 60 to which the cathode housing 50 is coupled. The first grid holder 135 to which the first grid 134 is attached is coupled to an upper portion of the fixing plate 60 which is in contact with the ceramic ring 20, and the second upper portion of the stepped portion 21. The second grid holder 143 to which the grid 142 is attached is coupled to each other.

The present invention as described above, by increasing the holding force to the first grid 134 and the second grid 142 to prevent short circuit due to the thermal deformation of the second grid 142, and simplify the assembly by grid coupling structure You can do it.

Description

Grid Coupled Structure of Low Voltage Driving Microwave Oscillator Tube

The present invention relates to an ultra-high frequency oscillation tube of a microwave oven, in detail, the first grid holder constituting the ultra-high frequency oscillation tube is coupled to the upper part of the fixing plate, and the second grid holder coupled to the upper part of the first grid holder is ceramic By fixing by a ring, it is configured to increase the holding force to the first grid and the second grid, and to simplify the grid coupling structure.

In general, microwaves are irradiated with food to cook foods by dielectric heating using frictional heat caused by the translational motion of water molecules contained in foods. A magnetron is provided that operates as.

The magnetron is a kind of two-pole vacuum tube that generates ultra-high frequency, and is composed of an input unit through which power is input as shown in FIG. When power is applied, hot electrons generated from the filament of the cathode 1 are emitted into the working space 4 between the tip of the plurality of vanes 3 coupled to the inner wall of the cylindrical anode 2 and the filament, and this working space In (4), a high voltage of 4 kV is applied between the cathode 1 and the vanes 3 constituting the anode 2 to form an electric field in the above-described working space 4.

At this time, the space 4 is provided with a magnetic circuit composed of a magnet 5 and a magnetic pole 6, thereby applying a magnetic field to the hot electrons, and thereby hot electrons perform a cycloid movement.

Subsequently, the energy generated according to this movement is transmitted to the vanes 3 and the straps 8, and through the output unit composed of the antenna 7 connected to the vanes 8 and the A ceramic 9 and the A seal 10, etc. Transfer to the cooking chamber to thaw or cook food.

When the magnetron emits hot electrons from the cathode (1), the electrons are accelerated under the influence of the electric field and the magnetic field, and move to the anode (2) during the rotational movement. , Resonant frequency f = As described above, the resonance frequency is determined based on the values of 'L' and 'C' acting between the vanes 3 to generate microwaves, that is, ultrahigh frequencies when a predetermined resonance condition is satisfied.

By the way, the magnetron for the microwave oven having the above-described structure must be provided with a high voltage transformer and a high pressure diode as a peripheral device by operating by a high voltage of about 4 kW, and adopting a resonance method by electromagnetic movement in a magnetic field. Therefore, the need for a magnet has a high weight and at the same time consumes a lot of cost.

On the other hand, to solve the problem of the magnetron driven by a high voltage as described above, Korean Patent Application No. 97-36327 is filed by the present applicant is known.

The above-mentioned patent application No. 97-36327 is intended to generate a very high frequency by applying a DC power from the power generation unit boosting the AC 120V or 220V commercial power to 500-700V DC power.

As described above, the present invention emits hot electrons when the cathode 132 located above the heater 120 is heated according to the heat generated by the heater 120 as shown in FIG. The hot electrons are focused by a bias voltage of 50 to 100 V DC applied between the cathode 132 and the first grid 134 and pass through the second grid 142.

In this process, the hot electrons are accelerated by a potential difference between an operating voltage of DC 500 to 700 V applied between the anode 146 and the cathode 132 to induce a surface current between the anode 146 to form a microwave. Meanwhile, microwaves formed according to this process are radiated through the antenna 150 in the center of the anode 146.

In addition, a feedback rod 160 for feeding back part of the microwaves formed in the output cavity 140 to the input cavity 140 is installed at the center between the input / output cavities 130 and 140 to amplify the power of the microwave and resonate. Let's do it.

In particular, unlike the conventional magnetron operating at a high voltage of 4 kW, such a low-voltage driving ultra-high frequency oscillator tube has a low voltage of 500 to 700 V, so the voltage can be stepped up without a separate boosting transformer to simplify the structure of the product. Visible effects such as increased safety, lighter weight of the product, and mass production at lower prices were expected.

On the other hand, in the low-voltage driving ultra-high frequency oscillator tube, the first grid 134 and the second grid 142 made of ultra-thin plates are fixed at a constant interval while the first grid 134 and the second grid are fixed. Since the short circuit of the grid 142 should be prevented, the first grid holder 135 and the second grid holder 143 may be attached to the outer circumferential surfaces of the first grid 134 and the second grid 142 as shown in FIG. 3A. The mechanical strength of the first grid 134 and the second grid 142 is reinforced.

In addition, through holes are formed radially inside the first grid holder 135 and the second grid holder 143, and then the first grid holder 135 and the second grid holder 143 are formed. The lower part of the second grid holder 143 is supported by the upper part and the upper part of the first grid holder 135 is supported by the lower part by inserting the ceramic pin 131 having the flange part 131A into the through hole as shown in FIG. 3B. Meanwhile, the first grid holder 135 and the second grid holder 143 are spaced apart from each other by a flange portion 131A while maintaining a constant gap therebetween.

However, as described above, when the first grid holder 134 and the second grid holder 143 are supported by the ceramic pins 131, a plurality of ceramic pins 131 must be coupled to each other. A lot of manpower is consumed to join each component.

In addition, the contact force between the ceramic pin 131 and the second grid holder 143 is extremely limited so that the fixing force on the second grid holder 143 coupled to the upper portion is reduced.

In particular, since the support force for the first grid holder 134 and the second grid holder 143 is not maintained between the ceramic fins 131, the heat is conducted from the heater 120, so that the first grid 134 is inclined. When the thermal deformation occurs in the second grid 142, the portions of the first grid 134 and the second grid 142 which do not act as the ceramic pins 131 are in contact with each other. A problem occurs such that a short circuit occurs between the first grid 134 and the second grid 143 to which a high pressure of several hundred volts or more operates.

The present invention has been made to solve the problems occurring in the low-voltage ultra-high frequency oscillation tube as described above, the technical problem of the present invention is to couple the first grid holder constituting the low-voltage driving ultra-high frequency oscillation tube to the upper part of the fixed plate, By fixing the two grid holders with a ceramic ring, a means for increasing the contact area between the first grid holder and the second grid holder to increase the holding force to the first grid and the second grid and simplifying the grid coupling structure is provided. It is to provide.

In the technical problem of the present invention as described above, in the low-voltage driving ultra-high frequency oscillator tube in which the first grid and the second grid are coupled in parallel to the upper portion of the cathode that emits hot electrons as the heater generates heat,

The upper portion of the fixing plate to which the cathode housing is coupled is attached a ceramic ring having a stepped portion at the inner circumferential end thereof, and the first grid holder to which the first grid is attached is attached to the upper portion of the fixing plate which is inscribed with the ceramic ring. It is achieved by providing a grid coupling structure of the low-voltage driving ultra-high frequency oscillator tube, characterized in that the upper portion is coupled to the second grid holder attached to the second grid, respectively.

Hereinafter, an embodiment of a grid coupling structure of a low voltage driving ultra high frequency oscillation tube according to the present invention will be described in detail with the accompanying drawings.

1 is a schematic cross-sectional structural view showing an example of a magnetron for a microwave oven having a conventional structure;

2 is a cross-sectional structure diagram of a conventional low voltage driving ultra-high frequency oscillation tube,

3A is a detailed view of main parts of a conventional low voltage driving ultra-high frequency oscillator tube

Figure 3b is a perspective view showing a ceramic pin used in the coupling of the first grid holder and the second grid holder in a conventional low voltage driving ultra-high frequency oscillator tube,

4 is a perspective view of a ceramic ring according to the present invention,

5 is a detailed view of the main portion of a low-voltage driving ultra-high frequency oscillation tube to which the present invention is applied.

<Explanation of symbols for main parts of drawing>

20: ceramic ring 21: step

50: cathode housing 60: fixed plate

120: heater 132: cathode

134: first grid 135: first grid holder

142: second grid 143: second grid holder

4 is a perspective view of a ceramic ring according to the present invention, and FIG. 5 is a detailed view of a main portion of a low-voltage driving ultra-high frequency oscillation tube to which the present invention is applied. The grid coupling structure of the low-voltage driving ultra-high frequency oscillation tube according to the present invention is a first grid ( The first grid holder 135 coupled to the outer circumferential surface of the 134 to fix the first grid 134 to the upper side of the fixing plate 60, and the second grid to fix the second grid 142 to the upper side of the fixing plate 60. By coupling the holder 143 by the ceramic ring 20, the fixing force between the first grid 134 and the second grid 142 is increased.

Here, the first grid holder 135 for fixing the first grid 134 includes an insulator choke 70 including a cathode housing 50 for fixing components such as the heater 120 and the cathode 132. Directly bonded to the upper portion of the disk-shaped fixing plate 60 to provide a coupling space, such as, the outer peripheral surface has a state inscribed from the ceramic ring 20 by being coupled to the ceramic ring 20.

The ceramic ring 20 fixes the second grid holder 143 including the second grid 142 from the first grid 134 and the first grid holder 135 directly bonded to the upper portion of the fixing plate 60. It is to be spaced apart at intervals, the inner peripheral end is formed with a stepped portion 21 is in close contact with the lower and outer peripheral surface of the second grid holder 143.

At this time, the step portion 21 is the first grid 134 and the first directly bonded to the upper portion of the fixing plate 60 in the state that the bonding of the second grid holder 143 including the second grid 142 is completed. The upper surface portion of the stepped portion 21 is flatly processed so as to maintain parallelity from the grid holder 135, and the upper surface portion and the lower portion of the stepped portion 21 are formed in parallel with each other.

In addition, by setting the height ('h' portion of the figure) of the vertical surface formed between the upper surface portion and the lower portion of the step portion 21 in consideration of the gap between the first grid 134 and the second grid 142 stepped portion 21. As the second grid holder 143 is bonded to the upper portion of the c), the gap between the first grid 134 and the second grid 142 is accurately maintained.

On the other hand, the ceramic ring 20 is coupled to the second grid holder 143 and the fixing plate 60 by the adhesion of the glass cement in the bonding process with the second grid holder 143 and the fixing plate 60 is made. In this case, the ceramic ring 20 is extremely poor in adhesiveness due to its characteristics, and thus, metallizing is formed on the joining surface of the fixing plate 60 or the stepped portion 21 to which the second grid holder 143 is coupled. By improving the adhesive force by the treatment, the coupling between the fixing plate 60 and the second grid holder 143 is thereby smoothly made.

Referring to the operation of the present invention as described above, the grid coupling structure of the low-voltage driving ultra-high frequency oscillation tube according to the present invention, the potential difference between the hot electrons emitted from the cathode 132 in accordance with the heating of the heater 120 during the generation of the ultra-high frequency By supporting the first grid 134 and the second grid 142 to be accelerated by the first grid 134 and the second grid 142 to maintain a constant gap.

Looking at the bonding process of the present invention, first, an adhesive such as glass cement is applied to the lower portion of the ceramic ring 20, and then the ceramic ring 20 by the cathode housing 50 by the heater 120 and The cathode 132 is attached to the upper portion of the fixed plate 60 is coupled.

In addition, the first grid holder 135 described above is attached to the upper part of the fixing plate 60 exposed through the inner circumferential surface of the ceramic ring 20 by bonding the first grid holder 135 on which the first grid 134 is completed. ) Is coupled to the ceramic ring 20 in an inscribed state.

Subsequently, after completion of the above process, the glass cement is coated on the stepped portion 21 formed on the ceramic ring 20, and then the second grid holder 143 on which the second grid 142 is attached is bonded. Let's go.

In this case, the ceramic ring 20 has a height h between the upper surface portion and the lower portion of the stepped portion 21 in consideration of the gap between the first grid 134 and the second grid 142, the stepped portion described above As the second grid holder 143 is bonded to the upper surface of the 21, the first grid 134 and the second grid 142 are coupled in a state where the gap is accurately maintained, and the second grid holder 143 is provided. ) Can be facilitated by one member, while simplifying the support structure for the first grid 134 and the second grid 142.

In particular, since the lower portion of the second grid holder 143 supported by the ceramic ring 20 is in close contact with the upper surface portion of the stepped portion 21 over the entire portion, the second grid 142 according to overheating. Even when thermal deformation occurs, the stepped portion 21 stably supports the lower portion of the second grid holder 143.

Thus, contact with the first grid 134 due to the partial lowering of the second grid 142 is prevented.

As described above, according to the present invention, the first grid holder 135 constituting the low voltage driving ultra-high frequency oscillation tube is coupled to the upper portion of the fixing plate 60, and the second grid holder 143 is formed by the ceramic ring 20. By fixing, the contact area between the first grid holder 135 and the second grid holder 143 can be increased to maintain a strong fixing force on the first grid 134 and the second grid 142, and in particular, the second grid ( Since the lower part of the second grid holder 143 to which the 142 is attached is in close contact with the upper surface of the stepped portion 21, the first grid may be formed even when heat deformation occurs in the second grid 142 due to overheating. Short circuit due to contact between the 134 and the second grid 142 can be prevented.

In addition, while the gap between the first grid 134 and the second grid 142 is accurately maintained by the step portion 21 formed in the ceramic ring 20, the second grid holder 143 ) Is made by a single member to facilitate the assembly, and to simplify the support structure for the first grid 134 and the second grid 142 can be obtained a number of effects, such as. .

Claims (1)

In the low-voltage driving ultra-high frequency oscillating tube in which the first grid 134 and the second grid 142 are respectively coupled in parallel to the upper portion of the cathode 132 that emits hot electrons as the heater 120 generates heat, On the upper portion of the fixed plate 60 to which the cathode housing 50 is coupled, a ceramic ring 20 having a stepped portion 21 is attached to the inner circumferential front end thereof. The first grid holder 135 to which the first grid 134 is attached is coupled to an upper portion of the fixing plate 60 in contact with the ceramic ring 20. The grid coupling structure of the low-voltage driving ultra-high frequency oscillator tube, characterized in that the upper part of the step portion 21, the second grid holder 143 to which the second grid 142 is attached to each other.