JPS5813939A - Cooking device - Google Patents

Abstract

PURPOSE:To prevent an erroneous operation in a cooking device in which a heater is provided with its distance to the food to be cooked arbitrarily, by a method wherein, when said distance is detected to be insufficient for imparting scorching to the food, the energization to the heater is interrupted. CONSTITUTION:When a door switch 12 and a switch 19 of a timer 18 are closed in case that a common contact 14 of a changeover switch 13 is individually conducted with a contact 16 in the state that a heater 8 is approached to food to be cooked, the heater 8 is heated, and the food 7 is charred. In case that the heater 8 is disposed at the position isolated upwardly from the food when the food 7 is charred, a thermistor 10 provided in the vicinity of the heater 8 disposed at the upper position is abruptly heated. Accordingly, the output of a comparator 21 becomes ''H'' level in a short time, thereby conducting a transistor 24, and opening a relay switch 27 through the relay 25. In this manner, the heater 8 is deenergized, and a buzzer 28 is sounded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a DI4 cooking appliance such as a grill that heats and browns an object to be cooked.

Traditionally, in cookers that have both the function of a microwave oven that performs high-wave heating and the function of a grill that browns the food, there is a scorch in the heating chamber where the food is stored. A heater is provided, and the heater is displaced upward away from the food placed in the heating chamber during heating, and when browning, the heater is moved upwards into the heating chamber. The heater is brought close to the food to be cooked. In such a cooker, place the heater close to the object so as not to draw attention to it. # In particular, when cooking with browning is less frequent than when cooking with frequency dielectric heating, it is necessary to use the heater 1-w to brown the browning. - Tends to forget operations close to fM 0 An object of the present invention is to provide a cooker that allows the operator to operate the heater without making mistakes when browning the food to be cooked. FIG. 1 is a simplified vertical cross-sectional view of a cooking device 1 according to an embodiment of the present invention.
A turntable 4 is provided horizontally at the bottom of the . This turntable 4 is rotationally driven around a vertical axis by a motor 5. On the turntable 4, the amount of food to be cooked @7 is listed. Inside the heating chamber 3, electromagnetic waves are generated by a 1-gnetron 6. This electromagnetic wave causes high-frequency dielectric heating of the tA target. At this time, the turntable 4 rotates, and the food to be cooked 7 is evenly heated.

A heater 8 is provided in the heating chamber 3, and the heater 8 can be freely moved toward and away from the food to be cooked 7. In this embodiment, the heater 8 is raised away from the food 7 as shown by the solid line, and is lowered close to the food 7 as shown by the phantom line 9. The upper and lower positions can be adjusted manually. By bringing the heater 8 to the position indicated by the imaginary line 9 and energizing the heater 8 in close proximity to the object 7 to be cooked, the object 7 to be cooked is radiantly heated and a char is formed.

On the ceiling 31 of the heating chamber 3, a thermistor 1O is arranged as a temperature detection element. This thermistor IO is close to the heater 8 at a position shown by a solid line in FIG. 1, when the heater 8 is separated from the food to be cooked 7. A fan 11 is provided to exhaust smoke, water vapor, etc. inside the PA room 3 to the outside.

2 d between the electrical circuits associated with the magnetron 6, heater 8 and thermistor lO. When the door for opening and closing the heating chamber 3 is closed, the switch 12 becomes conductive. When performing high frequency heating, the changeover switch 1 is turned on.
The common contact 14'k of the changeover switch 13 (switch to the separate contact 15 of the switch 10 for conduction).
The two individual contacts 16 are electrically connected. A high voltage generation circuit 17 for applying a high voltage to the magnetron 6 is provided between the door switch 12 and the changeover switch 13. A timer switch 19 of a timer 18 is connected in series to the 0 changeover switch 13. .

By making the common contact 14 of the changeover switch 13 conductive to the individual contact 15 and setting the timer 18, the timer switch 19 is interrogated for a predetermined time; The thermistor IOK, which generates electromagnetic waves and is resistant to electric heating by 1-mmvl, has a resistor 20 connected in series. A connection #X, 429, between the thermistor lO and the resistor 20 is given to one input of the comparator 21. The other voltage of the comparator 21 is supplied with the voltage at the connection point 30 set by the resistor 22.23. The thermistor IO has a characteristic that when heated, the resistance at both ends thereof decreases. Comparator 21 derives a high level signal to conduct transistor 24 when the temperature detected by thermistor IO exceeds, for example, 1800 and the voltage at node 29 is lower than the voltage at node 30. When the transistor 24 is turned on, the relay coil 26 of the relay 25 is excited, the relay switch 27 is turned on and off, and the buzzer 2 is turned on.
8 rings. The relay switch 27 is connected in series with the heater 8 and is connected to the door switch 12 and the changeover switch 13.
are interposed between the individual contacts 16 of the

FIG. 3 shows the relationship between the temperature of the thermistor IO and the vertical position of the heater 8 in the heating chamber 3.

When the heater 8 is located at an upper position PIK6 near the ceiling 31 as shown by the solid line in FIG.
The temperature rises to a moderate level.

Further, when the heater 8 is lowered to the position P2 shown by the imaginary line 9 and approached the food to be cooked 7 in order to brown the food, the thermistor 1O is heated to, for example, 100°C at most. It can be seen that the vertical position & of the heater 8 in the heating chamber 3 corresponding to the overflow detected by the thermistor lO is shown in Fig. 4. When the heater 8 is at the upper Ki position as shown by the east line in FIG. 1, when the heater 8t-power is applied at time t14c, @
As shown by the edge 11, the temperature of the thermistor lO rises rapidly.0Also, when the heater 8 is lowered and set to the position shown by the virtual &+9, when the heater 8 is energized at the time tl of t-#, the temperature of the thermistor lO rises rapidly at aII-12. As shown, a heater 8 with a fast temperature increase rate was placed close to the physical object 7 as shown by imaginary -9, and the common contact 14 of the changeover switch 13 was electrically connected to the individual contact 16. In this case, when the door switch 12 and the timer switch 19 of the timer 18 are turned on, the heater 8 is heated, and the
A brown mark will form.

In this case, the thermistor 10 is heated only to about 1000 ℃ at most, as is clear from FIGS. 3 and 4. Therefore, the output of the comparator 21 remains at a low level, the transistor 24 remains disconnected, and the relay switch 27 remains conductive.

When browning the to-be-cooked food @7, I accidentally moved the heater 8 upwards as shown by the solid line in Figure 1.
Assume that the is powered on.

In this case, the thermistor 10 rapidly freezes to a high temperature in a short period of time, as shown by curve II in FIG.

Therefore, the output of the ratio soft 621 becomes high level in a short time after the power is applied to the heater 8, and the transistor 24 becomes conductive. Therefore, the relay coil 26 of the relay 25 is energized, and the relay switch 27 is cut off. In this way heater 8
is deenergized and the buzzer 28 sounds.

As another embodiment of the present invention, a relay switch is interposed between the individual contacts 15 of the changeover switch 13 and the voltage generating circuit 17, and the relay switch is cut off by excitation of the relay coil 26 of the gold relay 25. It's okay.

In this way, dry firing in which the magnetron 6 is energized without the food to be cooked 7 stored in the heating chamber 3 is prevented.

As described above, according to the present invention, the temperature detection element detects that the heater is energized at a position away from the object to be cooked. v114 It becomes possible to reliably perform the operation of keeping the physical object 7 close to the physical object 7. Further, it is possible to avoid energizing the heater 8 while the food to be cooked remains connected to the heater 1, thereby preventing waste of electric power costs.

[Brief explanation of the drawing]

No. 1- is a simplified vertical cross-sectional view of a cooking appliance 1 according to an embodiment of the present invention, FIG. 2 is an electric circuit diagram related to the magnetron 6, heater 8, and thermistor 1o shown in FIG.
This figure and FIG. 4 are graphs showing the temperature of the thermistor IO corresponding to the upper and lower positions 11 of the internal pressure of the heating chamber 3 of the heater 8. 1...Cooking device, 3...Heating chamber, 6...Magnetron, 7...To be cooked, 8...Heater, lO...Thermistor, 21...Comparator, 25...・Relay agent Patent attorney Kei Nishikyo Part 1 Figure 1

Claims (1)

[Claims] The heating chamber is equipped with a heater for radiant heating of the food to be cooked in the heating chamber, and the heater is provided so as to be movable toward and away from the food to be cooked. A cooking method characterized in that a temperature detection element is arranged in proximity to the temperature detection element, and the output of the temperature detection element at K is detected when the heater is energized with electric power in a state in which the heater is in proximity to the temperature detection element. vessel.