JPH0833568A - Cooker - Google Patents

Abstract

PURPOSE:To prevent idle cooking accurately even when the detection of the temperature of a pot is not normal by a method wherein the temperature of a lid is detected at the end of heating the pot in an immersion cooking process to monitor the temperature of the lid during the stoppage of heating and idle cooking is determined when the temperature of the lid exceeds that at the end of heating the pot by a specified temperature. CONSTITUTION:When an immersion cooking process is started with a microcomputer 31, induction heating of the pot 10 with an induction heating circuit 35 is controlled by an ON-OFF operation and then, the heating of the pot is stopped by an OFF control. At this point, a detection of idle cooking is performed and it is judged whether or not the temperature of a lid exceeds a value obtained by adding a specified temperature such as 27 deg.C to the lid temperature P1 at the end of the ON-OFF control. Then, when the lid temperature is found to exceed P1+27 deg.C, idle cooking is determined. Heating processing is stopped and annunciation with a buzzer is performed through a buzzer drive section 42. On the other hand, when the lid temperature is found not to exceed P1+27 deg.C while 200 sec. is determined to pass, a rice cooking process is started.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooker for heating a pot provided inside a cooking container for cooking.

[0002]

2. Description of the Related Art Conventionally, in a cooker of this type, for example, a rice cooker, a pot temperature sensor is provided at the bottom of the cooker body so that when the pot is set inside the cooker body, a pot temperature sensor is provided to contact the bottom of the cooker to empty the cooker body When heating the rice while the pan is still set, the pan temperature is monitored by the above pan temperature sensor to prevent the inner surface of the pan and the rice cooker body from being damaged due to abnormal heating. Accordingly, heating stop control has been performed to detect empty cooking and stop heating.

This heating stop control is carried out, for example, when the temperature of the pan detected after the start of heating of the pan exceeds a predetermined temperature in a short time that cannot occur when rice or water is contained in the pan, that is, when the pan is under load. When the temperature of the pan increases, and the temperature of the pan detected after heating the pan starts to rise at a temperature increase rate that is not possible when there is a load on the pan, the temperature of the pan detected after heating the pan starts When the temperature reaches the temperature, the heating is stopped, and when the temperature rise of the pan is detected while the heating is stopped and the pan is under load, error processing such as stopping the heating and displaying an error is performed. Was there.

[0004]

However, in such a cooker, the pot temperature sensor is brought into contact with the bottom of the pot set in the rice cooker body to detect the pot temperature, and the pot temperature is emptied according to the pot temperature. Since the cooking was detected, if the pot is set inside the rice cooker body with rice grains, rice grains, etc. on the bottom, it may be interposed between the pot bottom and the pot temperature sensor.

Further, the heat-sensitive portion of the pan temperature sensor repeatedly contacts the bottom surface of the pan each time the pan is set, so that the surface of the heat-sensitive portion of the pan temperature sensor may be damaged. Further, the bottom of the pan with which the heat-sensitive part of the pan temperature sensor contacts may be deformed. Further, the temperature detection accuracy may not be sufficient due to the variation in the dimensional accuracy of the pan temperature sensor.

In such a case, the temperature of the bottom of the pan that is being heated cannot be accurately detected, so that the temperature detected by the pan temperature sensor is blunted and detection is performed when the pan temperature is accurately detected. The difference from the temperature disappears.

Therefore, in the above heating stop control, the heating is continued even though it is an empty pan, or the cooking is subsequently stopped by erroneously determining that the pan is empty even though there is a load on it and stopping the heating. There was a problem that it could not be done.

Therefore, the present invention is intended to provide a cooker capable of reliably preventing empty cooking even when the detection of the pot temperature is not normal, and thus further improving the safety.

[0009]

DISCLOSURE OF THE INVENTION The present invention relates to a cooking device for heating a pot which is detachably provided inside a cooking container for cooking, and a pot heating means for heating the bottom of the pot and a lid. And a lid temperature detecting means for detecting the lid temperature, and a hot water cooking control means for performing a hot water cooking step of heating the pan for a predetermined time before heating the rice cooking step by heating the pan heating means and then stopping the heating for a predetermined time. When the pan heating by this hot water cooking control means is completed, the lid temperature is detected by the lid temperature detection means, and the lid temperature is monitored by the lid temperature detection means while the heating is stopped thereafter, and this lid temperature is controlled by hot water cooking. When the temperature of the lid is higher than a predetermined temperature at the end of heating the pot, the means for detecting empty cooking is provided.

[0010]

In the present invention having such a configuration, when the hot water cooking process is performed, the lid temperature is detected by the lid temperature detecting means when the pan heating by the hot water cooking control means is completed, and the heating is stopped thereafter. The lid temperature is monitored, and when the lid temperature becomes a predetermined temperature or higher than the lid temperature at the end of heating of the pan of the hot water cooking control means, empty cooking is detected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to an electromagnetic induction heating cooker configured as a rice cooker will be described below with reference to the drawings. FIG. 1 shows an electromagnetic induction heating cooker in which an outer frame 1 contains an inner frame 2 formed of synthetic resin in a bottomed tubular shape. This inner frame 2 integrally has a flange 3 on the outer periphery of the upper part.
Is locked to the opening edge portion at the upper end of the outer frame 1, whereby the inner frame 2 is supported in the outer frame 1.

Induction coils 4 and 5 are attached to the outer bottom surface and the lower portion of the outer surface of the inner frame 2, and the induction coils 4 and 5 are covered with a coil cover 6. An opening 2a is formed in the center of the bottom surface of the inner frame 2, and a pan temperature sensor 7 is attached to the center of the bottom surface of the coil cover 6,
The pot temperature sensor 7 projects to the inner bottom portion of the inner frame 2 through the opening 2a.

On the outer side of the induction coils 4 and 5, in order to prevent the leakage of the magnetic flux of the induction coils 4 and 5, a plurality of materials having a high magnetic permeability mainly composed of iron oxide are sintered. Are provided so as to be orthogonal to the winding direction of the induction coils 4 and 5. Further, a magnetic shield plate 9 made of aluminum is provided on the outer peripheral side of the ferrite cores 8 ...

A cooking container 10 as a pan for cooking rice is housed inside the inner frame 2 in a removable manner. A flange 11 which is bent outward is integrally formed at the opening edge of the upper end of the cooking container 10, and the flange 11 is hooked on the opening edge of the upper end of the inner frame 2, whereby the cooking container 10 is formed.
Are supported in the inner frame 2. And this cooking container 10
A predetermined gap is secured between the outer surface of the and the inner surface of the inner frame 2.

A lid 12 is rotatably attached to the upper surface of the outer frame 1 via a hinge 1a, a heat radiating plate 13 is provided on the lower surface of the lid 12, and the lower surface of the heat radiating plate 13 is covered with a lid. 14 and an inner lid 15 are attached, and the opening at the upper end of the cooking container 10 is opened and closed by the inner lid 15.

The outer frame 1 is provided with a lid clamp 12a on the side opposite to the hinge 1a, and the lid clamp 12a is provided.
The lid 12 is releasably locked by means of this locking, the opening at the upper end of the cooking container 10 is closed by the inner lid 15, and the lid packing 14 is in close contact with the upper surface of the flange 11 of the cooking container 10. Further, when the lock is released, the lid 12 is pivoted upward with the hinge 1a as a fulcrum to rotate the cooking vessel 10
The opening at the top of the can be opened.

The inner lid 15 is formed with a plurality of small holes 15a for allowing the steam in the cooking container 10 to flow out, and the lid 12 is provided with a steam port 16 for discharging the steam to the outside. Further, the heat dissipation plate 13 of the lid body 12 is provided with a cover heater 17 for heating the heat dissipation plate 13 and a cover temperature sensor 18 as a cover temperature detecting means for detecting the temperature of the heat dissipation plate 13.

Since this lid temperature sensor is in non-contact with the pan, it is possible to perform stable and highly accurate temperature detection. I am supposed to do it. Further, a body heater 19 is provided in the middle part of the outer periphery of the inner frame 2.

A control board 20 is provided on the inner bottom of the outer frame 1, and an inverter circuit for applying a high frequency current to the induction coils 4 and 5 is provided on the control board 20. A cooling fan 22 driven by a fan motor 21 is provided at the inner bottom portion of the outer frame 1, an intake port 23 is formed on the bottom surface of the outer frame 1 so as to face the cooling fan 22, and a side surface of the outer frame 1 is provided. An exhaust port 24 is formed in the lower part.

The outside of the outer frame 1 is sucked into the outer frame 1 through the intake port 23 by the rotation of the cooling fan 22, and this air is blown toward the control board 20. The control board 20 is cooled.

The cooking container 10 is composed of a container main body 25 made of a non-magnetic metal material, and a heating layer member 26 made of a magnetic metal material provided in a portion extending from the bottom surface to the lower side surface of the container main body 25. .

A heating layer member 2 made of a magnetic metal material
6 is opposed to the induction coils 4 and 5 provided in the inner frame 2 with a predetermined space, and the pot temperature sensor 8 is in contact with the central portion of the outer bottom surface of the cooking container 10 to make the pot temperature sensor 8
The temperature of the cooking container 10 is detected by.

During cooking, a high frequency current is supplied to the induction coils 4, 5 by the inverter circuit of the control board 20, and an alternating magnetic field is generated in the induction coils 4, 5 by this high frequency current. And the cooking container 10 arranged in the magnetic field
An eddy current flows through the heating layer member 26, and the Joule heat generated by this eddy current causes the heating layer member 26 to generate heat, which is conducted to the container body 25, whereby the contents in the cooking container 10, that is, rice and water. Is heated.

The temperature of the cooking container 10 is sequentially detected by the pan temperature sensor 8, and the heating amount of the cooking container 10 is adjusted according to a preset control sequence according to the detected temperature. With this adjustment, rice cooking and heat retention are performed. Be done.

As the non-magnetic metal material forming the container main body 25 of the cooking container 10, for example, aluminum having good heat conduction and light weight is used, and as the magnetic metal material forming the heating layer member 26, for example, ferritic stainless steel ( SUS4
30) is used.

The heating layer member 26 is embedded in the portion extending from the outer bottom surface of the container body 25 to the lower portion of the side surface so that the outer surface thereof is exposed to the outer surface of the cooking container 10, and integrally joined to the container body 25. Has been done.

As shown in FIG. 2, the control board 20 is provided with a microcomputer 31 as a control unit main body. The microcomputer 31 receives the detection signal from the pan temperature sensor 7 and the lid temperature sensor 18, the pan detection sensor 32 for detecting that the pan 10 is set in the inner frame 2, and the command signal from the operation switch 43. It is supposed to be done.

Further, the microcomputer 31 is provided with a time counting circuit 31a for counting time. Further, a microcomputer drive power source 33 for driving the microcomputer 31 is connected to the microcomputer 31. When the power of the cooker is not turned on, the backup power supply 34 for backing up the microcomputer driving power supply 33 is connected.

Furthermore, this microcomputer 3
From 1, the induction heating control circuit 35 as a pot heating means for heating the pot 10 set in the inner frame 2, the heater driving unit 36 for driving the body heater 17 and the lid heater 19, and the fan motor 21 are driven. Motor drive unit 37, display drive unit 39 for displaying an error on display unit 38, and buzzer 41
A control signal is output to the buzzer drive unit 42 that drives the.

The induction heating control circuit 35 supplies the high frequency current to the IH oscillation circuit 44 based on a control signal from the IH (electromagnetic induction) oscillation circuit 44 and the microcomputer 31 which supplies the high frequency current to the induction coils 4 and 5. A high frequency current adjusting circuit 45 for adjusting is provided.

The microcomputer 31 includes an inner frame 2
When the pan 10 is set and the operation switch 43 gives a command to start cooking rice, the control operation as shown in FIGS. 3 and 4 is performed. Specifically, the hot water cooking step, the rice cooking step, the evening step, and the heat retaining step as shown in FIG. 6 are sequentially performed. In the figure, a graph x1 shows a change in the output temperature of the pan temperature sensor 7 in each process, and a graph x2 shows a change in the output temperature of the lid temperature sensor 18 in each process.

First, the microcomputer 31 starts the hot water cooking process in ST (step) 1. In this hot water cooking process, the induction heating of the pan 10 by the induction heating circuit 35 is turned off for 40 seconds, and the on / off control is repeated for 20 seconds to turn it on and off for 240 seconds to perform induction heating.
Turn off for 00 seconds to stop the heating of the pot (hot water cooking control means).

Here, in the first half of the hot water cooking process, the induction heating circuit 35 performs on / off control to control the pot 10.
However, if the same heat transfer capacity can be transferred to the pan, the induction heating circuit 3 is heated.
The heating may be performed only by the ON control by 5. In this case, for example, the heating may be performed with an IH output lower than the IH output when performing the on / off control by the induction heating circuit 35.

Then, the empty cooking is detected during the off control in the hot cooking process. The reason why the idle cooking is detected during the off control instead of during the on / off control is as follows.

That is, when the pot 10 has no load, that is, when the pot 10 does not contain rice or water, the lid temperature is higher than that when the pot 10 is loaded with radiant heat from the inner surface of the pot 10. Although the amount becomes large and the temperature of the space inside the pan rises quickly, there is a time delay from the heat generation of the pan 10 before the radiant heat from the pan 10 warms the space. For this reason, the lid body 1 at the time of the off control, which takes time from the end of the on / off control,
This is because it is effective to detect empty cooking by monitoring the temperature of the lid 12 because the temperature rise of 2 becomes large.

The reason why the empty cooking is detected in the hot water cooking step is as follows. That is, in order to surely determine that the cooking is empty, the heating time may be set to be long, but if the setting is made in this way, if the cooking pot 10 has no load, the cooking pot 10 is not detected before performing the cooking. It is not suitable because it becomes a high temperature, and when there is a load on the pot 10, the water temperature in the pot becomes too high, which is unreasonable for cooking performance. That is, for example, the case where the stickiness temperature of rice is exceeded during hot water cooking. Therefore, the range that does not affect cooking performance,
That is, it is effective to perform the empty cooking detection during the hot water cooking process in which the temperature rise is relatively small.

The above-mentioned hot water cooking step is specifically ST2.
Then, the induction heating of the pan by the induction heating circuit is turned off, and the time counting by the time counting circuit 31a is started. Then, in ST3, it is determined whether 20 seconds have elapsed. If it is determined that 20 seconds have elapsed at this time, the induction heating of the pan 10 by the induction heating circuit 35 is turned on in ST4, and the time counting circuit 31a starts counting the time.

Subsequently, in ST5, it is determined whether 40 seconds have elapsed. If it is determined that 40 seconds have passed at this time, it is determined in ST6 whether 240 seconds have passed.
And if it is determined that 240 seconds have not passed,
Returning to the process of ST2, when it is judged that 240 seconds have passed, the induction heating of the pot 10 by the induction heating circuit 35 is turned off in ST7, and the lid temperature at this time, that is, the hot water cooking process is turned on / off in ST8. The lid temperature P1 at the end of the control is detected by the lid temperature sensor 18, and the time counting by the timing circuit 31a is started.

After that, the lid temperature is monitored, and in ST9, it is determined whether or not the lid temperature is equal to or higher than a temperature obtained by adding a predetermined temperature to P1 such as 27 ° C. (idling detection control means). The predetermined temperature here is in order to prevent the rice from being cooked in the air, when there is a load, that is, when the pot 10 contains rice or water, the lid 12
It is set in consideration of the temperature rise rate in the vicinity, and
It is not limited to 7 ° C.

Then, at ST9, the lid temperature is P1 + 27 ° C.
When it is determined that the above is the case, it is determined that the rice is cooked empty, and the heating process is stopped in ST10. Furthermore, ST1
In 1 the buzzer notification is given via the buzzer drive section 42, and in ST12 the display section 38 is sent via the display drive section 39.
Error is displayed.

On the other hand, the lid temperature is P1 +2 in ST9.
If it is determined that the temperature is not 7 ° C or higher, 20 in ST13.
It is determined whether 0 second has elapsed. At this time, if it is determined that 200 seconds have not elapsed, the process returns to ST9 and 2
When it is determined that 00 seconds have elapsed, the process moves to A shown in FIG.
The rice cooking process is started in ST14.

Note that such a series of on / off control and off control may be performed a plurality of times. Figure 6 shows two times
This is a case where off control and off control are performed. FIG. 5 shows details of the first on / off control and the off control in the hot water cooking process. The outputs of the pan temperature sensor 7 when the above-mentioned hot water cooking process is performed are as shown in the graphs y1, y2 and y3 shown in the same figure, and the outputs of the lid temperature sensor 18 are the graphs y4 and y5 shown in the same figure. As shown in.

This graph y1 shows the temperature change of the pan 10 when rice and water are stored in the pan, that is, when the pan 10 is controlled to be cooked while being loaded, and the graph y2 is the pan. When rice and water are not stored in 10,
That is, it shows the temperature change of the pan 10 when the pan 10 with no load is cooked and controlled. Also, graph y
3 is the case where the pan 10 is controlled by boiling without load, and when the temperature detection is abnormal, for example, rice grains are interposed between the pan temperature sensor 7 and the pan bottom to detect the normal pan temperature. The temperature change of the pan 10 when it cannot be performed is shown.

The graph y4 is the pan 1 when there is no load.
0 shows the temperature change of the lid body 12 when the hot water is cooked and controlled, and the graph y3 shows the lid body 12 when the pot 10 is cooked and cooked without load and when the temperature detection is abnormal. Shows the temperature change of.

In the above rice cooking process, 1200 W of I
After induction heating the pot until boiling is detected with H output, 100
Induction heating at 0 W IH output and heating by the lid heater 17 and the pan heater 19 are performed by on / off control.

Specifically, first, at ST15, 1200 W
Induction heating of IH output is performed and the pot temperature is monitored. At this time, the lid temperature detected by the lid temperature sensor 18 is 90
Judge whether it is ℃.

At this time, if it is determined that the lid temperature is 90 ° C., boiling detection based on the lid temperature is started in ST17. In ST18, the temperature rise rate K / T (° C./sec) of the lid temperature detected by the lid temperature sensor 18 is a predetermined value, for example, 2 /
It is determined whether or not the temperature is 100 (° C./second) or less.

The temperature rise rate of the lid temperature is 2/100.
When it is determined that the temperature is lower than (° C / sec), the boiling temperature detection by the lid temperature sensor 18 is terminated, the pot temperature at this time is detected by the pot temperature sensor 32 in ST19, and the pot temperature is set as the reference pot temperature P2. Set.

Subsequently, in ST20, the pot temperature is detected, and in order to reduce it to a predetermined heating amount for continuing boiling, on / off control by induction heating with an IH output of 1000 W and heating by the lid heater 17 and the pot heater 19 are performed. ON / OFF control of.

Thereafter, the pot temperature is monitored in ST21, and it is determined whether or not the temperature detected by the pot temperature sensor 7 has reached a temperature obtained by adding a predetermined temperature to P2, for example, 15 ° C. (dry-up detection).

Here, the pan temperature after the end of boiling detection is set as the reference pan temperature P2, and the temperature obtained by adding a predetermined temperature to this P2 is set as the rice cooking operation end temperature, that is, the dry-up detection temperature. For some reason.

That is, the pan temperature sensor 7 as described above.
When the temperature of the bottom of the pot is not accurately detected by, for example, the temperature of the pot temperature sensor may be 90 ° C. or 110 ° C. while the correct pot temperature is 100 ° C. at the time of boiling.

In such a case, if the dry-up detection temperature is set to a constant temperature, for example, 120 ° C., if the temperature detected by the pan temperature sensor 32 is 90 ° C., the dry-up detection temperature is 120 ° C. up to 30 ° C. Also because the temperature rises,
Burning occurs in the rice due to overheating, and the pan temperature sensor 32
When the detection temperature of is 110 ° C, the temperature rises only 10 ° C to the dry-up detection temperature of 120 ° C.
There is a risk that rice will be boiled due to insufficient heating.

Therefore, if the temperature obtained by adding a predetermined temperature (15 ° C.) from the temperature detected by the pan temperature sensor 7 during boiling is set as the dry-up detection temperature, the pan temperature sensor 7 during boiling
Even if there is a variation in the detected temperature from the
This is because the rice cooking operation is terminated when (° C.) has elapsed, and thus the rice cooking process at an appropriate temperature can be performed.

In ST21, when it is determined that the temperature detected by the pan temperature sensor 7 has reached P2 + 15 ° C., the process proceeds to B. That is, in ST22, the induction heating is stopped,
In ST23, the purging process is started and the time counting by the time counting circuit 31a is started.

In this Murashiri process, on / off control by induction heating and heating on / off control by the lid heater 17 and the pot heater 19 are performed so that the temperature in the pan is maintained at 95 ° C to 105 ° C. Do for a minute.

Specifically, first, in ST24, the correction value P3 of the reference pan temperature P2 is set. This correction value P3 is
When the temperature detected by the pan temperature sensor 7 is 95 ° C to 105 ° C, this temperature is set, and when the detected temperature is 105 ° C or higher, the temperature is set to 105 ° C. If the detected temperature is 95 ° C or lower, the temperature is set to 95 ° C.

The reason why the reference pot temperature P2, which is the pot temperature after the end of boiling detection, is corrected to the correction value P3, is as follows. That is, since the induction heating circuit 35 turns off the induction heating of the pan 10 for a long time in the unevenness process, the pan temperature sensor is not affected by the magnetic fields of the induction coils 4 and 5, and is more effective than in the rice cooking process. Shift to a lower temperature. Therefore, as in the rice cooking process,
If the purging process is carried out based on the temperature at the time of boiling, there will be excessive heating, and the charred rice will become stronger.

For example, when the temperature at the time of boiling is relatively high at 110 ° C., if the temperature control of the muddling process is executed with 110 ° C. as a reference, the rice cooking process shifts to the muddling process and the pot temperature is changed. If the temperature detected by the sensor 7 shifts to a lower temperature of 105 ° C, the temperature difference of 5 ° C
Excessive heating will result. On the contrary, if the temperature is relatively low during boiling, the heating will be insufficient.

Therefore, it is effective to correct the reference pan temperature P2 to an appropriate correction value P3. The correction value P3 is set to 105 ° C when the temperature detected by the pan temperature sensor 7 is 105 ° C or higher, and 95 ° C when the temperature is 95 ° C or lower.
However, since the temperature of the rice is usually around 100 ° C. even if there is some variation, the correction value P3 is used in order to execute the mumming process within a temperature range close to the temperature of the normal rice. The upper limit is 105 ° C and the lower limit is 95 ° C.

Subsequently, in ST25, it is determined whether or not 13 minutes have elapsed. At this time, if it is determined that 13 minutes have not passed yet, 100 seconds have passed in ST26, and the temperature detected by the pan temperature sensor 7 is the correction value P set in ST24.
It is judged whether or not the temperature has reached a temperature obtained by adding a predetermined temperature to 3, for example, 2 ° C.

Then, 100 seconds have passed and the correction value P3 +
If it is determined that the temperature has reached 2 ° C., induction heating of 800 W IH output is started in ST27. Subsequently, in ST28, it is determined whether 10 seconds have elapsed, or whether the temperature detected by the pan temperature sensor 7 has reached a temperature obtained by adding a predetermined temperature, for example, 6 ° C., to the correction value P3.

At this time, if it is judged that 10 seconds have passed or the temperature detected by the pan temperature sensor 7 has reached the correction value P3 + 6 ° C., the induction heating of the 800 W IH output is turned off in ST29, and ST25 is selected. Return to processing.

When it is determined in ST25 that 13 minutes have elapsed, the purging process is ended, and in ST30, the heat retaining process is started. As shown in FIG. 6, this heat retaining step is performed after the end of the heat retaining initial step of controlling the on / off of the lid heater 17 and the body heater 19 and then on / off control of induction heating in addition to the lid heater 17 and the body heater 19. Carry out the process.

In the present embodiment having such a structure, when the pan 10 is set in the inner frame 2 and the operation switch 43 issues a command to start cooking rice, first, hot water cooking as shown in FIGS. 5 and 6 is performed. Carry out the process.

The induction heating circuit 35 is used in this hot water cooking process.
After the induction heating of the pot 10 is turned off for 40 seconds and the on-off control is repeated for 20 seconds, for 240 seconds, the induction heating is turned off for 200 seconds. here,
The case where the on / off control and the off control are performed twice will be described. Of these, the details of the first on / off control and the off control are shown in FIG. During this first off control, detection of empty cooking is performed.

That is, for example, when the pan 10 with a load is subjected to the hot water cooking process, the output temperature from the lid temperature sensor 18 does not exceed P1 + 27 ° C. as shown in the graph y5 in FIG. It is determined that there is, and the next rice cooking process is executed.

On the other hand, when the hot water cooking process is performed in the pan 10 with no load, the lid temperature is lower than that in the case where there is no load of rice or water in the pan. The amount of radiant heat increases and the temperature rise in the space inside the pan becomes faster.
However, since there is a time lag in heating the space in the pot from the pot 10, the temperature change of the lid body 12 is indicated by the graph y in FIG.
As shown in 4. Therefore, the temperature of the lid 12 is P1.
Since the temperature exceeds + 27 ° C, it is determined that the rice is cooked empty and the heat treatment is stopped. Furthermore, with the buzzer notification,
An error is displayed on the display unit 38.

As described above, by monitoring the lid temperature, even if the accuracy of detecting the pot temperature is poor due to the presence of rice grains between the pot bottom and the pot temperature sensor 7, the lid temperature is affected. Therefore, even when the detection of the pot bottom temperature is abnormal, it is possible to accurately detect the empty cooking. Therefore, safety can be improved.

Since the empty cooking is detected during the off control of the hot water cooking process, it is possible to cope with the time delay when the space inside the pan is heated from the pan 10 as described above.
For this reason, it is possible to detect the cooked rice more accurately.

As described above, when the pan 10 is under load, the next rice cooking process is started. In other words, in this rice cooking process, the pot 1
After induction heating 0, the induction heating with the IH output of 1000 W and the heating by the lid heater 17 and the pan heater 19 are turned on.
Performed by off control.

At this time, the end temperature of the rice cooking process, that is, the dry-up detection temperature is determined by the pan temperature sensor 7 at the time of boiling detection.
It is set to the temperature at which the pan temperature rises from the reference pan temperature P2, which is the detection output of, to 15 ° C.

Therefore, even if the pot temperature sensor 7 cannot accurately detect the pot temperature or the temperature detection varies, an appropriate rice cooking process can be performed. That is, even when the temperature during boiling is relatively low, for example, when the temperature during boiling is 90 ° C., the dry-up detection temperature is 105 ° C., and when the temperature during boiling is 80 ° C., the dry-up detection temperature is Since the temperature is 95 ° C, it is possible to prevent the rice from burning due to excessive heating.

Even when the temperature during boiling is relatively high, for example, when the temperature during boiling is 110 ° C., the dry-up detection temperature is 125 ° C., and the temperature during boiling is 11 ° C.
When the temperature is 9 ° C., the dry-up detection temperature is 134 ° C., so that raw cooking of rice due to insufficient heating can be prevented.

When the rice cooking process as described above is completed, the purging process is started. In this stripping process, on / off control by induction heating and heating on / off control by the lid heater 17 and the pan heater 19 are performed for 13 minutes so that the temperature in the pan is maintained at 95 ° C to 105 ° C. At this time,
The timing of ON / OFF control by induction heating is determined based on the elapsed time of ON or OFF and the temperature at the end of the rice cooking process, that is, the correction value P3 set to the dry-up detection temperature.

As a result, even if the pot temperature sensor 7 cannot accurately detect the pot temperature or the temperature detection varies, it is possible to prevent the rice from burning and simmering properly, and to carry out an appropriate stripping process. You can

Further, the correction value P3 is obtained by the pan temperature sensor 7
If the temperature detected by is 95 ° C to 105 ° C, it is set to this temperature, and if the detected temperature is 105 ° C or higher, 105 is set.
If the temperature is set to ℃ and the detection temperature is below 95 ℃, 9
Since the temperature is set to 5 ° C, the normal rice temperature is 100
The purging process can be performed within a temperature range close to ° C. As a result, it is possible to set the target of the automatic temperature adjustment in consideration of the detection situation such as the detection failure of the pan temperature sensor 7.

Therefore, even if there is a temperature detection failure of the pot temperature sensor 7 due to the coating of the pot 10 or the variation of the dimensions of the pot body, or the presence of rice between the pot temperature sensor 7 and the bottom of the pot, it is caused by excessive heating. It is possible to prevent the occurrence of charring and the occurrence of raw simmering due to insufficient heating, and there is no variation in cooking performance between uses.

Further, in the induction heating cooker according to the present embodiment, the pot itself generates heat. Therefore, if the heat exchange of water on the inner surface side of the pot 10 is not smoothly performed, the heat generating layer on the outer surface becomes high in temperature. Therefore, the temperature detected by the pan temperature sensor 7 brought into contact with the bottom of the pan may become high and the temperature detection accuracy may deteriorate. It is particularly effective to reset the temperature for each process and perform heating control.

In this embodiment, the induction heating cooker utilizing induction heating and heater heating is described as the cooking device, but the cooking device is not limited to this. It may be applied to a cooking device such as a rice cooker that uses only the rice.

[0081]

As described in detail above, according to the present invention, it is possible to provide a cooking device which can prevent the uncooked food from being cooked even when the temperature of the pan is not normally detected, and thus can further improve the safety. Is.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an induction heating cooker according to an embodiment of the present invention.

FIG. 2 is a block diagram of a control unit of the induction heating cooker according to the embodiment.

FIG. 3 is a flowchart showing a control operation of a hitting process performed by the microcomputer shown in FIG.

FIG. 4 is a rice cooked by the microcomputer shown in FIG.
The flow chart which shows the control operation of the unevenness and heat retention process.

FIG. 5 is a diagram showing a temperature change of each sensor in a dipping process according to the present embodiment.

FIG. 6 is a diagram showing a temperature change of each sensor in each process in the present embodiment.

[Explanation of symbols]

 2 ... Inner frame 10 ... Pot 12 ... Lid 18 ... Lid temperature sensor 31 ... Microcomputer 35 ... Induction heating circuit

Claims (1)

[Claims] 1. A cooking device for heating a pan that is detachably provided inside a cooking container for cooking, and a pan heating means for heating the bottom surface of the pan and a lid provided on the lid for detecting the lid temperature. The lid temperature detecting means, the hot water cooking control means for heating the hot water for a predetermined time before performing the rice cooking step by heating the hot water heating means, and the hot water cooking control means for performing the hot water cooking step for a predetermined time, and the hot water cooking control When the heating of the pot by the means is completed, the lid temperature is detected by the lid temperature detecting means, and the lid temperature is monitored by the lid temperature detecting means while the heating is stopped thereafter. When the temperature exceeds the lid temperature at the end of heating,
A cooking device, comprising: an empty cooking detection control means for detecting empty cooking.