KR830000180Y1 - High frequency heater - Google Patents

Abstract

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Description

High frequency heater

1 is a cross-sectional view illustrating a conventional heater unit microwave oven.

2 is a cross-sectional view showing the configuration of a heater apparatus in a conventional microwave oven.

3 and 4 are configuration diagrams of a heater unit microwave apparatus unit according to an embodiment of the present invention.

5 is an electric circuit diagram of the microwave oven.

6 is another embodiment of the present invention.

The present invention relates to a high frequency heating apparatus including a heater in a heating chamber.

A microwave oven with a high frequency heating device, for example, a heater, integrates a microwave oven function and an electric oven function. When cooking cooked food in a short time from the inside, a high frequency generator such as a magnetron Range cooking is performed by the generated high frequency radio wave, and the surface of the food to be cooked is pressed slightly, or cooking is performed by baking with delicate temperature control. The oven is cooked by the heating action of the heater.

The microwave oven with such a heater is comprised as shown in FIG. 1, for example. In the drawing, reference numeral 11 denotes a body of a microwave oven to which a heater is attached, and the body 11 includes an inner box 12 and an outer box 13 connected from the front, and a heating chamber 14 is attached to the inner box 12. ) Is formed.

A door 15 is provided on the front surface of the double body 11 to open and close the front opening of the heating chamber 14.

In the heating chamber 14, the shelf 16 is set in a horizontal state, and the upper heater 17 is provided in the upper part of this shelf 16, and the lower heater 18 is provided in the lower part. The upper heater 17 and the lower heater 18 are fitted to the device portions 19a and 19b formed on the rear wall 19 of the heating chamber, respectively.

In the device sections 19a and 19b corresponding to each of the upper heater 17 and the lower heater 18, the upper heater 17 and the lower heater 18 are respectively heated in order to prevent a risk of electric shock. The upper heater 17 and the lower heater 18 become detachable from the heating chamber rear wall 19 in consideration of the insulation at the rear wall 19 and the cleaning time in the heating chamber 14. On the shelf 16, a plate 21 into which the food to be cooked 20 is placed is placed. In the space formed by the inner box 12 and the outer box 13, a high frequency generator, for example a magnetron 22, is arranged, and the high frequency radio wave generated from the magnetron 22 is used to guide the waveguide 23. It is guided to the upper surface part of the heating chamber 14 through this, and is radiated in the heating chamber 14.

Conventionally, the apparatus parts 19a and 19b of the upper heater 17 and the lower heater 18 are comprised as FIG. 2 shows the upper heater 17 as a representative, for example.

That is, the through-hole 24 is formed in the rear wall 19 of the heating chamber, and the through-hole 24 is a space in which the damping pipe 25 is formed as the outer box 13 in the same shape as the shaft. It is set inward. At the front end of the damping pipe 25, a plurality of contact pieces 26a, 26b are formed by bending elastic metal pieces, respectively. Is connected, and this contact piece 26a, 26b ... Is connected to the ground circuit through the damping pipe 25, and propagates from the heating chamber 14 to the heater 17 to short-circuit the high frequency radio wave attenuated by the damping pipe 25 to the ground circuit. In other words, the heater 17 is inserted into the shaft center portion of the damping pipe 25, and the heater 17 is projected outward of the inner box 12 so as to sandwich the tip end with the contact pieces 26a and 26b. The connector connector 27 is arrange | positioned at the position into which the front end of 17) is inserted, and this connector 27 connects and fixes the front end of the heater 17. As shown in FIG.

Here, the heater 17 is covered with a heater avoidance 28 made of polyethylene, for example, with its outer circumference except the tip thereof, and the end of the heater sheath 28 is covered with an insulating ring 29. . The heater shell 28 is provided with contact pieces 26a, 26b,... Will be in contact with. The connector 27 is protected by the insulator 30 and again protects the entire device portion 19a with the metal cover 31.

However, as a microwave oven with a heater having such a configuration, if the heater 17 is detachably attached to the rear wall 19 of the heating chamber, the contact pieces 26a, 26b... The contact pressure deteriorates and a gap arises with the heater shell 28, and a spark occurs in this gap. When the spark is prominent, the heater shell 28 may be punctured to cause breakdown, which may be a cause of fire. In addition, the high frequency electric wave propagated to the heater 17 passes through the above-mentioned gap, and this high frequency electric wave propagates to the connector 27, which causes the occurrence of interference of electric wave leakage, making it difficult to maintain safety. do.

The present invention has been made in view of the above circumstances, and its purpose is to prevent the occurrence of spikes due to poor contact in the heater device portion, to prevent the occurrence of fire, and to prevent leakage of high frequency radio waves. It is to provide an effective high frequency heating device.

Next, an embodiment of the present invention will be described with reference to the drawings.

3 and 4 show the apparatus 19a of the upper heater 17 as a representative, and the same parts as those in FIG. 2 are indicated by the same reference numerals. That is, the through-hole 24 is formed in the rear wall 19 of the heating chamber, and the damping pipe 25 is attached to this through-hole 24. As shown in FIG. At the distal end of the damping pipe 25, a plurality of contact pieces 26a, 26b are formed by bending the elastic metal pieces, respectively. Is connected, and this contact piece 26a, 26b ... Is connected to the ground circuit through the damping pipe 25, and propagates to the heater 17 in the heating chamber 14 to connect the high frequency radio wave attenuated by the damping pipe 25 to the ground circuit.

Then, the connector 27 is protected by the insulator 30 and again protects the entire device portion 19a by the metal cover 31. The metal cover 31 is provided with a hole 31a through which one end of the one contact piece 26a passes, and a switch device plate 32 is provided above the hole 31a. The switch device plate 32 is provided with a micro switch 17a, which has an actuator 17b in contact with one end of the contact piece 26b, and the contact piece 26a. By opening outward, the electric circuit is turned on.

Here, the heater 17 is covered with a heater shell 28 made of polyethylene, for example, the outer peripheral portion except the tip portion, and the heater shell 28 is in contact with the contact piece 26a in a set state as shown in FIG. The projection part 28a which touches (26b) is formed, and the edge part of the heater outer cover 28 is covered and protected by the point ring 29. As shown in FIG.

That is, in the state where the heater 17 is reliably inserted like FIG. 3, the projection part 28a touches the curved part of the contact piece 26a, and is in the state which pushes up the contact piece 26a. Thus, the heater shell 28 is connected to the ground circuit through the contact piece 26a and at the same time operates the actuator 17b of the switch 17a, so that the switch 17a is closed.

In addition, as shown in FIG. 4, when the insertion setting state of the heater 17 is incomplete, the protrusion 28a of the heater shell 28 does not touch the curved portion of the contact piece 26a. Without pushing up, the actuator 17b of the switch 17a does not operate, and the switch 17a is not closed.

5 shows an electric circuit of the microwave oven as described above, wherein the power from the commercial power supply 33 is drawn through the main switch 34, and is switched through the relays 35a and 35b. 36 is selectively supplied to the high frequency generation circuit 37 including the magnetron 22, or the upper and lower heaters 17 and 18. As shown in FIG. In addition, as shown in FIGS. 3 and 4, the power obtained through the main switch 34 is connected to the upper and lower heaters 17 and 18 via the switches 17a and 18a, respectively, in series. It draws out and is supplied to the relay 35 via the parallel circuit of the relay contact 35c and the star art switch 38, and the timer switch 39a again. The relay 35 sets the relay contacts 35a-35c to the closed state in the excited state.

That is, in the state where the upper heater 17 and the lower heater 18 are normally inserted and set, the switches 17a and 18a are closed together, and in this state, the main switch 34 is closed and the star When the art switch 38 is closed, the relay 35 is excited and the contacts 35a-35c are closed while the timer switch 39a is closed by the timer 39. Then, in accordance with the selection state of the switching switch 36, high frequency radio wave generation or heating operation by the heaters 17 and 18 is started, and the timer 39 operates until the timer switch 39a is opened. . Here, the contact 35c is used for self holding of the relay 35.

Here, when at least one of the upper heater 17 and the lower heater 18, for example, the insertion setting state of the upper heater 17 is incomplete as shown in FIG. 4, the switch 17a is closed. If the star art switch 38 is pressed by mistake, the microwave oven does not operate. Therefore, in the high frequency radio wave heating chamber 14, the contact pieces 26a, 26b... Passes through the gap between the heater and the outer shell 28, there is no fear of leakage to the outside and stability is secured.

In the above embodiment, the same effect can be achieved even when the fall between the heater shell 28 and the heater 17 is used without providing the projection 28a in the heater shell 28, and the operation is performed in the first embodiment. Since it is the same as the case of FIG. 3 and FIG. 4, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

In the above embodiment, the microwave is attenuated by the attenuation pipe 25 and then short-circuited to the ground circuit. However, another method, for example, a choke space is provided. This space may be attenuated and then applied to a high frequency heating apparatus such as a short circuit to a ground circuit, and the same effects as described above can be obtained.

According to the present invention, an elastic contact piece for connecting the outer and outer heater shells to the ground circuit is provided, and at the same time, a switch for controlling the electric circuit in conjunction with the contact surface is provided. If the state is not in contact, the microwave oven does not operate and prevents the occurrence of unnecessary sparks in the heater unit, thereby preventing the occurrence of insulation breakdown and effectively preventing leakage of high frequency radio waves to the outside. It is possible to provide a high frequency heating device with excellent safety.

Claims (1)

In the nine-wave heating device comprising a heating chamber 14 and a high frequency generator 22 for supplying high frequency radio waves into the heating chamber, heaters 17 and 18 detachably mounted to the wall surface of the heating chamber; , The contact pieces 26a and 26b driven when the heater is mounted and operated in the mounting state thereof, and the switches 17a installed in the mounting portion of the heater to be closed in the heater mounting state and inserted into the power supply circuit in series with the contact pieces. High frequency heating device made of 18a).