JPS6030418B2 - High frequency heating device - Google Patents

Description

[Detailed Description of the Invention] One of the features of a microwave oven is that it heats only the food from within, and the container and the microwave oven (heating box) themselves do not get hot.

Recently, microwave ovens with an oven function have been released, but as is well known, an oven is a device that raises the temperature of the air inside the oven to cook food, so the heating box inevitably reaches a high temperature. However, users are told that ``the microwave is cold.''
Because of this image, there is a high risk of burns. The only way to cool down the ovens currently available on the market is to leave them to cool naturally, but if the oven is open, it gives the impression that the oven is hot, and if you want to use it again, you have to raise the temperature inside the oven again. Being cooled was actually a negative. On the other hand, the oven function of a microwave oven not only gives the impression of being ``cold,'' but also requires rapid cooling, especially in situations such as when thawing sashimi immediately after cooking in the oven. Considering only rapid cooling, one possible method would be to use a time switch for the oven that automatically starts rotating the fan motor when it reaches a certain point, and then stops after a certain period of time. However, this method has the following drawbacks. In other words, if you are cooking that requires heating at 186 degrees and accidentally set the setting for 12 minutes, the food to be cooked will not be completely cooked yet after 12 minutes have passed, and the food will still be heated at the same temperature. Although it requires heating for 3 minutes, it cools down rapidly. In this case, if additional heating is attempted for an additional 3 minutes, preheating time is required, which wastes energy. ■Cream puff skins will harden if cooled too quickly. Therefore, it is desirable to have a system that rapidly cools the device only when the user feels it is necessary, automatically turns off the power when cooling is completed, and notifies the user that cooling has ended. A method for achieving this will be described below. Figure 1 is a circuit diagram of the microwave oven of the present invention.
Next to the fuse, there is a selector switch 2 that switches between high frequency and heater, and when it is set to high frequency, the current flows through high frequency time switch 3, latch switch 4, door switch with short circuit 5, and temperature switch attached to the magnetron. 6 and reaches the high voltage transformer 7.

A neon lamp 8 for indicating high frequency energization, a timer motor 9 for opening the time switch 3, and a fan motor 10 for cooling the magnetron are connected in parallel between the door switch 5 and the temperature switch 6. Note that a resistor is inserted in the neon lamp 8 and a thermal fuse 11 is inserted in series with the fan motor 0. A phase advance capacitor 2, a diode 13, a varistor 14, and a magnetron 15 are connected to the secondary side of the high voltage transformer 7. When the switch 2 is turned to the heater side, it passes through a heater time switch 16 and a liquid expansion type temperature regulator 17, and reaches a heater 8 of about 1.2 KW. A neon lamp 19 for indicating preheating is connected in parallel with the heater, and a neon lamp 20 for indicating heater energization is connected between the time switch 16 and the temperature controller 17.
, a timer motor 21 for a heater time switch, and a fan motor 22 for circulating hot air in the oven are connected in parallel. A resistor is connected in series with each of the neon lamps 19 and 20, and a resistor 23 and a cooling switch 24 are connected in series with the fan motor 22. The cooling switch is a single-circuit double-immersion switch, with a common contact connected to the fan motor 22, a normally closed contact connected to a resistor 23, and a normally open contact connected between the fuse and the changeover switch 2 via the temperature switch 25. Ru. Further, a neon lamp 26 for indicating completion of cooling is connected to the normally open contact. FIG. 2 shows another embodiment, in which the cooling switch 24 is connected to the magnetron cooling fan motor 10.
are inserted in series.

FIG. 3 is an exploded perspective view of the oven (heating box) of this embodiment. It is an aluminized iron plate with a diameter of 0.5.

There is a truncated conical constriction part 53 at the bottom of the main body, and a turntable is placed here. There are linear apertures 54 protruding inward on the left and right walls, on which metal plates are placed when baking bread. Also, on the right wall, there are a group of punched holes 55 for introducing magnetron cooling air into the oven (heating box).
and a square hole 5 for introducing high frequency from the magnetron.
There are 6. Also, in the center of the upper wall is a group of punched holes 5 for exhaust.
7, and a connecting portion 58 is also provided on the upper wall. A punching hole group 59 is provided inside a regular hexagon in the center of the partition plate 51, and a punching hole group 60 is also provided inside the square above and below the main body 50. Fix by spot welding.

The back plate 52 is provided with a truncated pyramid-shaped constriction part 62, a propeller fan 63 is provided in the center thereof, and a sheathed heater 65 held by an insulator 64 is provided around it.

Note that the sheathed heater 65 has a single layer on the top and left and right sides, and a triple layer on the bottom only. Corresponding to Figures 1 and 2, propeller fan 6
3 is driven by the fan motor 22, and the sheathed heater 65 is the heater 8. Further, bent portions 66 are provided on the top and left and right sides of the hair plate 52 and fixed to the flange portion 61 of the main body 50. The bottom part is not bent, but the two holes 67 are raised and screwed into the raised holes at the corresponding positions of the partition plate and flange part. The sheathed heater 65 has a single layer on the upper and left sides of the propeller fan 63, and a triple layer on the lower side. A flange portion 68 is also provided at the front of the main body 50 and is fixed to a door opening/closing mechanism (not shown).
Note that the inside of the main body 50 and the inside of the partition plate 51 lined with two-dot chain lines are subjected to a porous enamel treatment based on citric acid frit and using verdigris and manganese dioxide as an oxidation catalyst. FIG. 4 is a perspective view showing the internal state of the heater time switches (16 and 21), and the rotation of the timer motor 21 is transmitted to the large gear 81 via the small gear group 80.

Cams A83 and B84 are fixed to the shaft 82, and the large gear 81 is rotatably attached.The rotation of the motor 21 is transmitted to the shaft 82 by the friction plate 85, and the rotation of the motor 21 is transmitted to the shaft 82 by the shaft 82. The cam A has a disc-shaped outer circumference with a part cut out, so that the switch 16
is opened and closed. The cam B has a projection on a part of its disk-shaped outer periphery, which opens and closes the cooling switch 24, and a timer knob 86 is attached to the shaft 82. Fifth
The figure is a view of the area around the timer knob 86 on the operation panel, with the "Off" display at the top center, the time up to 2 hours displayed to the right, and the "Cooling" display to the left. There is.

The contact of the temperature switch 25 shall be closed at about 60 o'clock or more, and its temperature sensing part (not shown) is connected to the oven main body 50.
It is provided at the position shown in Fig. 3A on the outside of the With the above configuration, a microwave oven with an oven function capable of rapid cooling can be realized.

When cooking with the open function is completed and the time switch knob is in the state shown in Figure 5, as mentioned above, if slow cooling is required, such as for cream puff pastries or sponge cakes, close the door. Just leave it alone.

In other cases, after taking out the food to be cooked, turn the time knob 86 to the left until the "cooling" display is displayed, the fan motor will rotate and the food will be rapidly cooled. In the circuit shown in FIG. 1, ACIOOV is applied to the fan motor 22 through the resistor 23 during oven cooking, and 100V is applied directly to the fan motor 22 during cooling. Therefore, a higher velocity air is obtained during cooling than during cooking. If the door is open at this time,
Cooling air is exhausted from there. When it is difficult to keep the microwave oven door open in a small kitchen room, the cooling air is exhausted from the exhaust punching holes 57. As the open wall cools down, the temperature switch mounted on the oven wall opens its contacts, stops the fan motor from rotating, and also lights up the neon lamp 26. This lamp serves as a high temperature warning indicator. As shown in Figure 2, when the magnetron cooling fan motor 10 is used for cooling, the cooling air enters the oven (heating box) through the punching 55 and is discharged through the punching 57.When cooling is completed, the timer knob 86 is in a state showing the "cooling" display, but since the temperature switch 25 is working and the motor and lamp are not energized, it can be left as is.In case of reuse, Simply turn the timer knob 86 to the right.In other words, this timer m is
From the "off" position, turn it counterclockwise to start "cooling". After cooling, the knob does not return to the "off" position, but
The effect is the same as returning to the ``off'' position.

In other words, all the power is turned off, and if you want to use it again, just turn it clockwise to set the time. In this sense, the cooling switch can be said to self-reset. Also the first
As can be seen from FIG. 2, when the oven wall becomes hot, the temperature switch 25 closes and the neon lamp 26 lights up, which also serves as a danger display.

Although this embodiment uses a hot air circulation type oven, the same effect can be obtained even with a conventional type in which sheathed heaters are placed above and below the open oven, if a magnetron cooling fan is used for cooling.

Further, a gas flame or the like may be used as the heat source. As described above, according to the present invention, it is possible to realize a microwave oven with an oven function and a cooling circuit that can rapidly cool an open wall or the like when necessary, and can self-reset after cooling is completed.

Therefore, accidents such as burns are reduced, and a safe cooker can be provided.

[Brief explanation of the drawing]

1 and 2 are circuit diagrams of a high-frequency heating device showing an embodiment of the present invention, FIG. 3 is an exploded perspective view of the main part of the oven, and FIG. 4 is a perspective view of the inside of the main part of the timer. FIG. 5 is a front view of the timer knob portion of the operation panel. 18... Heater (high heat source), 16...
Time switch, 21"""Timer motor, 86""
"Timer knob, 25...Temperature switch, 22.
...Fan motor, 63...Propeller fan, 1
8,65...Season evening. Figure 2 Figure 1 Figure 4 Figure 5 Ship

Claims (1)

[Claims] 1 It has a time switch, a temperature switch, and a magnetron cooling fan motor or a hot air circulation fan motor, and the double throw switch is interlocked with the time switch, and the double throw switch operates in the opposite direction to the time setting of the time switch. The high-frequency heating device is configured to be in a closed state when operated, and to be connected to a temperature switch and a fan motor for cooling the magnetron or for circulating hot air, which are connected in series.