KR19990034702A - Heat Strain Reduction Grid of Microwave Oscillator for Microwave Oven - Google Patents

Abstract

The present invention relates to a grid for preventing heat deformation of microwave oven tubes for microwave oven, and has a circular disk shape corresponding to the cathode, and forms a plurality of rectangular slot groups at predetermined intervals from the center to the concentric circles, and the circumferential slot group. The distance between the slots and the distance between the slots of the center slot group is constant, but the overall slot area is characterized by maintaining the same area as the entire conventional slot, so the grid of the conventional microwave microwave tube In contrast, since a predetermined interval is formed between the slot groups by forming the slots of the grid into a plurality of concentric slot groups, the thermal expansion between the slots of the slot groups on the center side is reduced, thereby causing disconnection and cathodes due to thermal deformation. It can improve the heat transfer path when internal heat is discharged out by preventing contact with each other. Has a damaging effect.

Description

Heat Strain Reduction Grid of Microwave Oscillator for Microwave Oven

The present invention relates to a grid of microwave oven tubes for microwave ovens, and more particularly, to a heat deformation preventing grid that can significantly reduce heat deformation by uniformizing a heat transfer path.

Applicant's Korean Patent Application No. 97-36327 discloses a microwave oven tube for microwave oven which is simple in structure and can reduce the risk of high voltage and achieve light weight. As shown in FIG. 1, the ultra-high frequency oscillation tube is provided with a power input unit 110, a heater 120, an input cavity 130, and an output cavity in a filter box 105 having a cover 104 covered therein. 140 and the feedback rod 160 are provided, and the antenna 150 in the anode 146 is provided in the bracket 102. The installation space of the antenna 150 in the filter box 105 and the anode 146 maintains a vacuum.

The cathode 132, which is an electron radiator, emits hot electrons by the indirect heating method by the heat of the heater 120, and the cathode 132 placed on the upper surface of the heater 120 is about 1000− by the heat of the heater 120. When heated to about 1300 ℃ emits hot electrons.

The input cavity 130 is a space surrounded by the cathode 132, the first grid 134, and the choke structure 136, and the cathode 132 is a ring-shaped disk having a hole formed in the center thereof. The first grid 134 arranged at a predetermined interval on the upper side of the N th) is applied with a bias voltage to control and focus electrons emitted from the cathode 132 to the input cavity 130. At this time, the first grid 134 and the cathode 132 is electrically insulated, that is, the direct current must be shielded, the surface current forming the microwave inside the input cavity 130 must be energized, for this purpose choke structure 136 is arranged between the cathode 132 and the first grid 134.

The output cavity 140 arranged on the top of the input cavity 130 is installed to face the top of the first grid 134 of the input cavity 130 so that electrons passing through the first grid 134 pass through the surface current. Is enclosed by a second grid 142 and an anode 146 having protrusions 144 protruding downward from the bottom surface. In this space, electrons focused on the input cavity 130 are densely modulated. Accelerated by the potential difference between the grid 134 and the second grid 142, the microwave is formed by the surface current induced in the second grid 142. The anode 146 that dissipates the slowed-down electron beam is also stacked with a plurality of cooling fins 148 to radiate heat.

The electrons focused on the input cavity 130 are densely modulated by the automatic shielding function of the bias power of the first grid 132 to pass through the first grid 132, and at this time, the input / output cavities 130 and 140 insulated from each other. When the operating voltage is applied, the potential difference is generated therebetween, and electrons passing through the first grid 132 are accelerated to pass through the second grid 142, so that surface current is generated in the output cavity 140. Induced. As a result, microwaves are formed in the output cavity 140, and the formed microwaves penetrate through the center of the anode 146 and are radiated through the antenna 150 formed in the output cavity 140. For this purpose, the coupling end 152 of the antenna 150 is located in the output cavity 140. The antenna ceramic 154 and the antenna cap 156 connected to the upper portion of the antenna 150 have the same structure as a conventional marknetron.

Meanwhile, a feed 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 and resonate the power of the microwave. .

However, as shown in FIG. 2, the first and second grids 134 and 142 of the conventional microwave microwave oscillation tube are identical to each other in a shape corresponding to the cathode 132 as a metal material, and The slot 170 is formed in the circumferential direction around the hole, and a predetermined gap is maintained by the ceramic pin 172 provided between the choke structure 136 and the output cavity 140, but the slot length l ) Is long, the distance between slots on the circumference (b) is greater than the distance between slots on the circumference (a), and the ratio of the distance between slots on the center of the circle to the distance between the slots on the circumference ( b / a) is large, and when the grid is thermally expanded at the operating temperature of 1000 ° C. to 1300 ° C. of the grid, the deformation of the slot part at the center of the center is severely deformed due to thermal deformation between the slots, resulting in disconnection or contact with the cathode. There was a problem that occurred.

Accordingly, the present invention has been devised in accordance with the present invention, to provide a thermal deformation preventing grid capable of preventing thermal deformation in a conventional microwave microwave tube.

As a means for achieving the above object, the present invention is a heat distortion prevention grid of the microwave oven for microwave oven, wherein the first and second grid is a circular disk shape corresponding to the cathode, concentric from the center A plurality of quadrangular slot groups are formed at predetermined intervals, so that the distance between the slots of the circumferential slot group and the slots of the distant slot group is constant, wherein the total area of the rectangular slot groups is It is characterized by keeping the same as the total area.

According to the present invention, the center of the center of the distance between the slots in the circumferential slot group even if the thermal deformation occurs between the slots by forming the slots of the grid into a plurality of slot groups on the concentric circle while making the entire area of the slots the same By making the distance between the slots of the slot group on the side uniform, the slot of the slot group on the far center has a mechanically stable structure against thermal deformation during the thermal expansion of the grid, and uniform heat transfer when the heat inside is discharged outward. Enhancement of heat transfer capacity by having a path reduces efficiency of the grid by reducing deformation of the grid.

1 is a cross-sectional view showing the structure of an ultra-high frequency oscillation tube employed in a conventional microwave oven,

FIG. 2 is a perspective view illustrating the first and second grids of FIG. 1;

3 is a schematic plan view showing a heat deformation preventing grid according to an exemplary embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

100: high frequency oscillation tube 102: bracket

104: filter box cover 110: power input unit

120: heater 130: input cavity

132: cathode 134: first grid

136: choke structure 140: output cavity

142: second grid 144: projection

146: anode 148: cooling fin

150 antenna 152 coupling end

154: antenna ceramic 156: antenna cap

160: feedback rod 170: square shape slot

172: ceramic pin 180,190,200: concentric slot group

300: heat deformation prevention grid

Hereinafter, with reference to the accompanying drawings will be described in detail the thermal deformation preventing grid of the microwave oven tube for microwave oven according to an embodiment of the present invention.

As can be seen from FIG. 3, the thermal deformation preventing grid 300 of the microwave microwave oscillation tube of the present invention has a circular disk shape corresponding to the cathode 132, and the first and second grids have the same shape. .

In the heat deformation preventing grid 300 of the present invention, a plurality of rectangular slot groups in which the slots 180, 190 and 200 are formed at predetermined intervals t on a concentric circle from the center of gravity are provided. Is formed. At this time, the total area of the rectangular slot group is preferably the same as the total area of the rectangular slot of the conventional grid. That is, a gap is formed between the slot groups so that the entire slot area is the same area, and the distance A between the slots 180 of the center slot group with respect to the distance A between the slots 180 of the circumferential slot group. Make the ratio of) uniform.

As described above, the thermal deformation preventing grid 300 of the present invention is thermally expanded when the cathode 132 reaches an operating temperature, that is, 1000 ° C. to 1300 ° C. due to the heat of the cathode 132, but the slot is maintained while maintaining the overall slot area in the same area. It is spaced in the military and maintains a uniform space between the slots to improve the heat transfer path, so that the thermal deformation between the slots of the slot group 180 in the center of the center is less, so that the cathode and each other by the disconnection and deflection of the slot Contact is prevented.

According to the present invention, since a predetermined interval is formed between slot groups by forming a plurality of slot groups of concentric circles, compared to a grid of a microwave microwave tube for a microwave oven, the slot group of the far center side The thermal expansion between the slots is reduced to prevent contact with the cathode by disconnection and deflection, and the heat transfer path can be improved when the heat inside is discharged, so the efficiency is effective.

Claims (2)

A power input unit, heat generating means for generating heat by receiving power from the power input unit, cathodes sequentially installed on the heat generating means at predetermined intervals, a first grid, and a choke structure provided between the cathode and the first grid; As the input cavity of the space surrounded by the cathode, the cathode is heated to a predetermined operating temperature by the heat of the heat generating means to emit hot electrons, the first grid is formed with a plurality of square slots, a bias voltage is applied to the cathode The choke structure conducts surface currents that form a microwave inside the input cavity, and direct current between the cathode and the first grid shields the input cavity, radiating heat. A plurality of cooling fins are stacked and arranged so as to extinguish the decelerated electron beam; Density modulated electrons focused in the input cavity into a space surrounded by a second grid installed on top of the first grid in the same shape as the first grid so that electrons passing through the first grid of the cavity pass to induce surface currents. And an output cavity accelerated by the potential difference between the first grid and the second grid, the microwave being formed by the surface current induced in the second grid, and radiating means for radiating the microwaves formed in the output cavity; In the grid of the microwave oscillation tube for microwave ovens comprising a feedback means provided between the input and output cavities to feed back part of the microwaves formed in the output cavity to the input cavity, The first and second grids have a circular disk shape corresponding to the cathode, and a plurality of square slot groups are formed at predetermined intervals from the center to the concentric circles, and thus the center of the distance between the slots of the circumferential slot groups. A grid for preventing heat deformation of microwave oven tubes, characterized in that the ratio of the distances between the slots in the slot group is equalized. The microwave oven of claim 1, wherein three square slot groups of the first and second grids are formed, and the total area of the slot groups is the same as the total area of the square slots. Strain relief grid.