JPS6035185Y2 - High frequency heating device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high-frequency heating device that includes a heater in a heating chamber and a device for circulating air within the heating chamber.

Conventionally, in high-frequency heating devices such as microwave ovens,
In addition to microwave cooking, which is performed by supplying high frequency waves emitted from a high frequency generator (magnetron) into the heating chamber, that is, the cooking chamber, it is also possible to perform oven cooking by installing multiple heaters in the cooking chamber and using the heat generation effect of these heaters. There is something I did.

By the way, in such a microwave oven, various operating states (grilling, fermentation, etc.) can be set during oven cooking, and a temperature controller is provided so that the temperature in the cooking chamber can be set to a predetermined value corresponding to the various operating states. ing.

This temperature adjustment is carried out by controlling the heater intermittently and circulating the air in the cooking chamber using a circulation fan to equalize the temperature in the cooking chamber and improve thermal efficiency.

However, in the above-mentioned high-frequency heating device, the temperature in the heating chamber does not rise immediately after the heater operates, and the circulation fan is rotated at this time, so the temperature rises in the heating chamber, that is, immediately after the start of cooking. It takes a long time for the temperature in the heating chamber to reach a constant temperature, resulting in poor efficiency.

Further, since the circulation fan is rotated while the heater is turned off due to the operation of the temperature regulator, the temperature inside the heating chamber decreases significantly.

Furthermore, when the door is opened during cooking, heat is exhausted outside the heating chamber by the fan, causing a sudden drop in temperature within the heating chamber.

As a result, if the door is opened during cooking, the food will not cook properly, and when the door is opened during or after cooking, hot air from the rotating fan may hit the user's face and hands, causing burns. There were drawbacks such as.

This invention was made to eliminate the above-mentioned drawbacks.
By using a circuit configuration that controls the heater and fan by the operation of the temperature controller and also includes a switch that stops the rotation of the fan when the door is opened, the temperature controller can be turned off for the first time immediately after the heater is activated. The circulation fan is stopped until the point in time, and the circulation fan is stopped when the heater is turned off due to the operation of the temperature controller.
Furthermore, when the door is opened after cooking or during cooking, the heater is continuously energized and only the circulation fan is stopped, resulting in high-frequency heating that improves cooking efficiency, improves cooking quality, and improves safety. The purpose is to provide equipment.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

Figure 1 shows the appearance of the high frequency heating device of the present invention.
Reference numeral 11 indicates a door for putting in and taking out food, 12 indicates an operation panel, 13 indicates a timer provided on the operation panel for setting the cooking time, and 14 indicates a temperature controller for setting the cooking temperature to a predetermined value. thermostat), 15 is a cooking switch for starting cooking.

As shown in FIGS. 2 to 4, the inside of the heating chamber (oven) is partitioned by a partition plate 17, and between this partition plate 17 and the back plate 18, air is directly connected to a motor 19. A circulation fan 20 is provided.

In addition, an air intake port 21 for sucking the heated air in the heating chamber 16 is provided at the central portion of the partition plate 17, that is, a portion corresponding to the fan, and further near both left and right ends of the partition plate 17. is provided with an exhaust port 22 for discharging heated air into the heating chamber 16.

Further, as shown in FIGS. 3 and 4, a shelf board 23 is provided in the heating chamber 16, and an upper heater 24 and a lower heater 25 are provided above and below the shelf board 23, respectively.

Therefore, the air in the heating chamber 16 heated by the upper and lower heaters 24 and 25 is sucked in from the air intake port 21 by the rotation of the fan 20 as shown by the arrow in FIG. 2, and then heated again through the air exhaust port 22. circulates within chamber 16.

Next, FIG. 5 shows an electric circuit of the high-frequency heating device configured as described above.

In FIG. 5, one end of the commercial power supply 27 is connected to the cooking switch 1.
5 to one end of a motor 131 of the motor timer 13 and a switch 132 operated by the motor 131.

The other end of the motor 131 is connected to the other end of the commercial power source 27 via a switch 133.

The other end of the switch 132 is connected to one end of the relay 28 and the movable contact 14c of the temperature regulator 14 via a normally open contact 28a□ of the relay 28.

The other end of the relay 28 is connected to the other end of the commercial power supply 27.

Further, the break contact 14a of the temperature regulator 14 is connected to one end of the relay 28, and the make contact 14b of the temperature regulator thermostat 14 is connected to the normally open contact 2 of the relay 28.
8a2 to one end of the relay 29, one end of the upper heater 24 via the normally closed contact 28b of the relay 28, and one end of the lower heater 25 via the normally open contact 29a of the relay 29. There is.

The other end of the relay 29 is connected to the other end of the commercial power source 27.

Further, at both ends of the relay 29, a door switch 30 and a fan motor 19 are connected, which are turned on and off by opening and closing the door 11.
A series connection circuit is connected.

Further, one end of the upper heater 24 and the lower heater 25 are connected to each other, and the other end is connected to the other end of the commercial power source 27, respectively.

Next, the operation of the high frequency heating device configured as described above will be explained with reference to FIG.

After opening the door 11 and placing the cooked food on the shelf board 23, open the door 1.
1 will be closed and the oven will be cooked.

Now, the temperature is set to, for example, 200° C. by the temperature regulator 14, the cooking time is set to, for example, m minutes by the timer 13, and the cooking switch 15 is turned on.

At this time, in the circuit of FIG. 5, the cooking switch 15,
When the switch 132 and the switch 133 are closed, the movable contact 14c of the lower temperature regulator 14 is connected to the make contact 14b side, so the upper heater 24 and the lower heater 25 are connected to the commercial power supply 27 through the normally closed contact 28b of the relay 28. Since current flows, these upper and lower heaters 24 and 25 are heated.

In this case, even though the door switch 30 is closed due to the closing of the door 11, the fan motor 19 does not rotate because the relay 28 is not driven.

Therefore, the temperature inside the heating chamber 16 is rapidly heated by the upper and lower heaters 24 and 25, as shown in FIG.

At time t1 when the temperature inside the heating chamber 16 exceeds a preset temperature of 200°C, the temperature regulator 14 is activated and the movable contact 14C of the temperature regulator 14 becomes the break contact iJ.
Since it is connected to the a side, no current flows through the upper and lower heaters 24 and 25, and they are turned off.

At this time, the current from the commercial power supply 27 is transferred to the break contact 1.
4a to the relay 28, the relay 28 operates, the normally open contact 28a1128a2 closes, and the normally used contact 28b opens.

Next, as shown in FIG. 6, at the time when the temperature inside the heating chamber 16 has fallen below the set temperature of 200° C., the temperature regulator 14 operates again, and the movable contact 14c changes to the make contact 14b.
connected to the side.

At this time, the relay 28 is held by the normally open contact 28a1, so the normally open contact 28a2 remains closed and the normally closed contact 28b remains open.

Therefore, current flows to the relay 29 through the make contact 14b and the closed normally open contact 28a2, causing the relay 29 to operate.

Since the normally open contact 29a is closed by the operation of this relay 29, the upper and lower heaters 24 and 2 are connected through this contact 29a.
A current flows through the heaters 5 and heats the upper and lower heaters 24 and 25.

On the other hand, the fan motor 1 is
Drive 9.

Therefore, the air in the heating chamber 16 heated by the upper and lower heaters 24 and 25 is sucked in through the air intake port 21 by the rotation of the fan 20, and then again from the air exhaust port 22, as shown in FIGS. 2 to 4. It circulates within the heating chamber 16.

The temperature inside the heating chamber 16 reaches the set temperature 20 as shown in FIG.
At time t3 when the temperature reaches 0° C. or higher, the temperature regulator 14 is turned off, and the hip rotation contact 14c is connected to the break contact 14a side.

Therefore, no current flows through the upper and lower heaters 24, 25 and the fan motor 19, and they are turned off.

On the other hand, when the door 11 is opened during or after cooking to check the doneness of the food, the door switch 30 is opened and no current flows to the fan motor 19, causing the circulation fan 2 to open.
The rotation of 0 stops.

However, the upper and lower heaters 24 and 25 are energized and continue heating.

After that, when the cooking time set by the timer has elapsed, the switch 132 opens, so the upper and lower heaters 2
The heating operations of 4 and 25 and the rotating operation of the fan 19 are stopped.

According to the high frequency heating device described above, the heater 24.2
Since the rotation of the circulation fan 20 is stopped immediately after the operation of step 5 (immediately after the start of cooking) until the time t1 when the temperature controller 14 is turned off for the first time (until the temperature in the heating chamber reaches a constant temperature), the rotation of the circulation fan 20 is stopped. It is possible to raise the temperature quickly without hindering the internal temperature rise.

Furthermore, when the heaters 24 and 25 are turned off by the temperature regulator 14, no heat source is supplied into the heating chamber 16, so the temperature naturally drops.

At this time, if the fan 20 continues to rotate, the temperature drop will increase and cooking will be hindered, but as described above, the rotation of the fan 20 is stopped to reduce the temperature drop.

Furthermore, if you want to check the doneness of the food during cooking, you can use the door 1.
Since the rotation of the fan 20 is stopped even when the fan 1 is opened, it is possible not only to prevent the temperature inside the heating chamber 16 from dropping rapidly, but also to prevent burns on the hands and face caused by the hot air generated by the rotation of the fan 20. can be prevented.

As explained above, according to the present invention, the rise time of the temperature in the heating chamber is short and the thermal efficiency is good, and when the heater is turned off, the temperature in the heating chamber does not drop much and the cooking is finished well. To provide a high-frequency heating device that does not discharge the heat in a heating chamber when cooking, has good thermal efficiency, allows for good cooking, and is safe without the fear of burns caused by hot air.

[Brief explanation of the drawing]

FIG. 1 is an external view of a high-frequency heating device according to an embodiment of the present invention, and FIGS. 2 to 4 are structural explanations schematically showing the inside of the device in FIG. 1 as viewed from the top, front, and side, respectively. 5 is an electric circuit diagram of the apparatus shown in FIG. 1, and FIG. 6 is a heating chamber temperature curve diagram for explaining the operation of the circuit shown in FIG. 11... Heating chamber, 14... Temperature controller (thermostat), 16... Heating chamber, 20.
...Fan, 24.25 ...Heater, 3
0...Door switch.

Claims (1)

[Scope of utility model registration request] a heating chamber, a heater provided in the heating chamber, a temperature controller that adjusts the temperature in the heating chamber to a preset value by controlling the heater on and off, and the heater from immediately after the on-operation to the first off-operation of the temperature regulator, and when the heater is turned off due to the off-operation of the temperature regulator, the heater is in a stopped state;
A high-frequency heating device characterized by comprising a circulation fan for circulating air in the heating chamber, which is controlled to be in an operating state when the heater is operating during periods other than these periods.