JPS6135850Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to improvement of internal temperature control during electric heating of a high-frequency heating device with an electric heating device.

Regarding high-frequency heating devices, in recent years, many so-called microwave ovens with built-in electric heating devices have come on the market. This microwave oven performs high-frequency heating and electric heating simultaneously or continuously in one heating chamber, and when performing both types of heating, the performance required for each heating chamber is different. .

In other words, when using high-frequency heating, it is preferable to increase the amount of ventilation in the heating room to prevent steam from accumulating inside the refrigerator.On the other hand, when heating with electric heating, it is preferable to increase the ventilation in the heating chamber in order to improve heating efficiency and maintain a constant temperature inside the refrigerator. It is preferable that the heating chamber be in a nearly sealed state. Hereinafter, the above-mentioned problems in the conventional example will be explained in detail with reference to FIGS. 1 and 2.

When the object to be heated 1 is dielectrically heated by high frequency waves irradiated from the magnetron 2, a large amount of steam is generated in a short period of time. In order to prevent this steam from adhering to the door 3 and the inner wall of the heating chamber 4 and reducing heating efficiency, the heating chamber is ventilated. 5 is a fan motor, and the wind after cooling the magnetron 2 is
The heating chamber is ventilated through an intake port 6 and an exhaust port 7 provided in the heating chamber 4.

Next, during electric heating, the upper heater 8 and the lower heater 9
is energized, and the air temperature within the heating chamber 4 rises.
At that time, the fan motor 5 is stopped, and forced ventilation within the heating chamber is not performed. However, as shown by the arrow in FIG. 1, the hot air heated by the upper heater 8 is discharged from the upper part of the intake port 6 and the exhaust port 7 due to the pressure difference and is cooled outside the heating chamber 4, so that the hot air is cooled again. As a result, a natural convection phenomenon occurs in which air is taken in from the lower portions of the intake port 6 and the exhaust port 7. 10 is a sensor for keeping the temperature of the heating chamber 4 constant, and is configured to sense the temperature of the hot air discharged from the heating chamber 4 and turn on and off the electricity to the heater 6 and the lower heater 7. .

In such a configuration, the air flow near the sensor is a mixture of hot air discharged from the heating chamber and cold air taken in from the outside, and the sensor can sensitively capture the temperature inside the heating chamber 4. was difficult. In addition, 11 is the sensor cover,
12 is a plate for placing a heated object, and 13 is a shelf.

The present invention focuses on such a phenomenon and can solve the above problems with an extremely simple configuration, and will be described below with reference to FIGS. 3, 4, and 5.

Each component in the figure and its operation are the same as those of the conventional example, but the intake port 6 and the exhaust port 7 provided in the heating chamber 4 are connected to the heated object placed on the uppermost shelf 13. It is located at a portion that is 1/2 or more of the effective height H between the dish 12 and the upper surface of the heating chamber 4. Further, the intake port 6 and the exhaust port 7 are each arranged to be long in the depth direction.

Furthermore, a sensor 10 and a sensor cover 11
is provided corresponding to the exhaust port 7, and similarly, the depth direction is formed in the longitudinal direction.

According to the above configuration, during electric heating, the temperature is gradually raised from the vicinity of the upper heater 8, that is, from the upper part of the heating chamber, when the upper heater starts energizing, and this heated hot air expands to become high pressure, and a part of it is exhausted. It is exhausted to the outside through the port 7. That is, it was confirmed in experiments that the air pressure existing in the upper part of the heating chamber (1/2H or more in FIG. 3) is always higher than the outside air pressure, and that no cold air flows in from the exhaust port 7. That is, from when the upper heater 8 starts energizing until the completion of cooking, the sensor cover 11
The air flow inside is as shown by the arrow in Figure 3.
It always flows from inside the heating chamber 4 to the outside. the result,
The sensor 10 can sensitively detect changes in the temperature inside the heating chamber. Furthermore, since the exhaust port 7 is formed to be long in depth, the temperature within the heating chamber can be captured over a wide range. The graph shown in FIG. 5 shows the relationship between the heating room air temperature A and the air temperature B near the sensor 10. According to the configuration of the present invention, ΔT in FIG.
(deg) could be made extremely small. Furthermore, since external cold air is no longer drawn into the heating chamber, the predetermined time t(s) from the start of energization of the heater until the inside of the heating chamber reaches a predetermined temperature can be shortened.

As described above, the present invention has a simple structure, and has brought about practical effects such as improving the delicate temperature control performance required for oven cooking such as cakes, improving heating efficiency, and reducing power consumption. It is extremely useful.

[Brief explanation of the drawing]

Fig. 1 is a front sectional view showing a conventional high-frequency heating device with an electric heating device, Fig. 2 is a sectional view of the same, Fig. 3 is a front sectional view showing an embodiment of the present invention, and Fig. 4 is a heating chamber of the same. FIG. 5 is a perspective view showing the internal temperature control state of the high-frequency heating device during electric heating. 4...Heating chamber, 6...Intake port, 7...Exhaust port,
10...Sensor, 11...Sensor cover, 1
2...Plate for placing the object to be heated.

Claims (1)

[Scope of utility model registration request] A heating chamber for storing an object to be heated, a high frequency generation means for dielectrically heating the object to be heated, an electric heating device provided at least near the upper surface of the heating chamber for electrothermally heating the object to be heated, and sensing the temperature in the heating chamber. A sensor for opening/closing the power supply circuit of the electric heating device, a shelf for selecting the height of the heating object mounting plate, and a side wall of the heating chamber for forced exhaust air in the heating chamber during dielectric heating. The exhaust port is located above the intermediate height between the top surface of the heating chamber and the heated object mounting plate when the heated object mounting plate is installed on the top of the shelf. The lower end of the exhaust port is located at a lower position than the electric heating device installed near the top surface of the heating chamber, and the lower end of the exhaust port is located at the same or lower position than the electric heating device installed near the top surface of the heating chamber corresponding to the exhaust port. A high frequency heating device characterized by being provided with the above sensor.