KR100266477B1 - Microwave oven - Google Patents

Abstract

PURPOSE: A microwave oven is provided to make an ultra high frequency oscillation tube compact and electron beams uniform, and increase the output efficiency thereof by attaching a coupling element having a rectangular shape to an antenna. CONSTITUTION: A microwave oven includes a coupling element(186) attached to an end part of an antenna of an ultra high frequency oscillation tube and formed in the shape of loop for effectively coupling a microwave energy formed in an output cavity(140) to emit via the antenna, increasing the output efficiency, a cathode(180) formed in the shape of circular plate disc and having a radius to be reduced in an electron emission area, and first and second grids(182,184) having a shape corresponding to the cathode and respectively formed with a plurality of circular holes having an equal opening area.

Description

microwave

The present invention relates to a microwave oven, and more particularly, to a microwave oven employing an improved ultra-high frequency oscillation tube capable of miniaturization and increasing efficiency.

Applicant's Korean Patent Application No. 97- discloses an ultra-high frequency oscillating tube for a microwave oven, which is simple in structure and can eliminate the risk of high voltage and achieve light weight. 1 and 2, the power input unit 110, the heater 120, the input cavity 130, and the filter box 105 are covered with the cover 104. The output cavity 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 emitter, emits hot electrons by an indirect heating method by the heat of the heater 120. That is, as shown in FIG. 2, when the cathode 132 placed on the upper surface of the heater 120 is heated to about 600-1200 ° C. by the heat of the heater 120, the electrons are emitted.

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 has a ring shape with a hole formed in the center thereof, as shown in FIG. 3. The first grid 134, which is arranged at a predetermined interval on top of the cathode 132, is applied to 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.

As shown in FIG. 4, the first and second grids 134 and 142 are identical to each other in the shape corresponding to the cathode 132 as a metal material, and have a slot-shaped quadrangular shape along the circumferential direction around an inner hole. An opening 170 is formed and a predetermined gap is maintained by the ceramic pin 172 provided between the choke structure 136 and the output cavity 140.

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, in the microwave oven employing such a microwave oscillation tube, since the cathode is a ring-shaped disk, unnecessary holes are formed in the center, and rectangular slit in which the opening shapes of the first and second grids are radially formed along the circumferential direction. Since it is a shape, there exists a problem that a uniform electron beam cannot be formed and there existed a subject of the efficiency increase in the ultra-high frequency oscillation tube for microwave ovens.

Accordingly, the present invention has been made in accordance with the present invention, to provide a microwave oven employing an ultra-high frequency oscillation tube that is more compact than the conventional ultra-high frequency oscillation tube and can increase the efficiency.

As a means for achieving the above object, the microwave oven of the present invention comprises a disk consisting of a disk disk and a cathode composed of a ring-shaped disk in a conventional ultra-high frequency oscillation tube, the first and second grid having a radial along the circumferential direction An ultra-high frequency oscillation tube formed with a plurality of circular holes in a rectangular slot-shaped opening portion is adopted.

According to one preferred embodiment of the present invention, the efficiency is increased by making a rectangular coupling member attached to the end of the antenna extending in the output cavity to form a loop in order to radiate the microwaves formed in the output cavity.

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

2 is an enlarged detail view of the main portion of FIG. 1;

3 is a perspective view illustrating the cathode of FIG. 2;

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

5 is a schematic cross-sectional view showing the structure of a novel ultra-high frequency oscillation tube employed in the microwave oven of the present invention;

6 is a detailed view showing the main part of FIG. 5;

FIG. 7 is a perspective view illustrating the cathode of FIG. 6;

FIG. 8 is a perspective view illustrating the first and second grids of FIG. 6.

Explanation of symbols on the main parts of the 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: slot-shaped rectangular opening

172: ceramic pin

Hereinafter, a microwave oven employing an ultra-high frequency oscillation tube according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

As can be seen from the figure, the microwave oscillation tube 100 employed in the microwave oven of the present invention has a cathode 180 having a disk shape, and the first and second grids 182, 184 having a disk shape. A circular hole 190 is formed therein in a shape corresponding to the cathode 180, and is attached to an end of the antenna 150 extending in the output cavity 140 to radiate microwaves formed in the output cavity 140. Other than the coupling member 186 in the form of a loop, it is the same as the structure of a conventional ultra-high frequency oscillation tube, so that the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

As shown in FIG. 6, since the coupling member 186 attached to the end of the antenna 150 has a loop shape, the microwave oscillating tube 100 employed by the microwave according to the present invention is connected to the output cavity 140. By effectively coupling the energy of the formed microwave radiation through the antenna 150, the output efficiency is increased.

In addition, the ultra-high frequency oscillation tube 100 employed by the microwave oven of the present invention, as shown in FIG. 7, the cathode 180 is compared with the conventional, when the current amount is the same, the radius is reduced in the same electron emission area The first and second grids 182 and 184 having a shape corresponding to the cathode have a plurality of circular areas with the same area as the opening area of the rectangular opening of the slot shape formed in the conventional grid, as shown in FIG. Since the hole 190 is formed, a uniform electron beam is formed while passing the same amount of current as in the prior art, thereby increasing output efficiency and compactly constructing an ultra-high frequency oscillation tube.

According to the present invention, compared with a microwave oven employing a conventional ultra-high frequency oscillation tube, it is possible to miniaturize due to the reduction of the radius of the cathode, the electron beam is uniformly formed, and effectively couple the microwave energy to increase the output efficiency Have

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 generation of the heat generating means to emit hot electrons, the first grid is applied a bias voltage to control and focus electrons emitted from the cathode The choke structure is configured to pass a surface current to form a microwave inside the input cavity, an input cavity shielding a direct current between the cathode and the first grid, and a plurality of cooling fins arranged to stack heat. Passing through the anode and the first grid of the input cavity A space enclosed by a second grid mounted on top of the first grid to induce surface current as electrons pass through it, accelerated by the potential difference between the first grid and the second grid while electrons focused in the input cavity are densely modulated And feed back an output cavity into which the microwave is formed by the surface current induced in the second grid, radiating means for radiating the microwave formed in the output cavity, and a portion of the microwave formed in the output cavity to the input cavity. In a microwave oven employing an ultra-high frequency oscillation tube composed of a feedback means provided between the input and output cavities, The cathode of the ultra-high frequency oscillation tube is a disk-shaped disk, and the first and second grids have a shape corresponding to the cathode, wherein a plurality of circular holes are formed inside the same area as the area formed in the cathode. Range. The microwave oven according to claim 1, wherein a coupling structure in the form of a loop is attached to an end portion of the antenna extending in the output cavity of the microwave oscillation tube.

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