JP2009052793A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker having high usability by improving accuracy in determining sensor abnormality, in the heating cooker 1 comprising a heat source 2 for heating a cooking container P, a temperature sensor 25 for detecting a temperature of the cooking container P, a sensor monitoring means 33 for determining whether the sensor abnormality where the temperature sensor 25 does not normally detect the temperature of the cooking container P, exists or not, and a heating control means 31 for stopping heating motion of the heat source 2 when the sensor abnormality is determined by the sensor monitoring means 33. <P>SOLUTION: The sensor monitoring means 33 determines the sensor abnormality when a condition that a detected temperature of the temperature sensor 25 is less than a prescribed reference temperature, and a temperature rise value per a prescribed time, of the detected temperature is less than a prescribed reference amount of change. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooking device provided with a temperature sensor for detecting the temperature of a cooking container such as a pan or a frying pan.

  In the conventional cooking device, when the detected temperature of the temperature sensor does not exceed the predetermined reference temperature even though the heating operation is being performed, it is determined that the temperature sensor is abnormal, and the heating operation is stopped. What has the function to prevent overheating of a cooking thing is known.

FIG. 4 is a schematic configuration diagram of a gas stove 7 exemplified as the above-described conventional heating cooker, and a gas burner 8 that heats a cooking container P such as a pan or a frying pan placed on the top of the gas stove 7 with the heat of combustion of the gas. And a control circuit 9 for controlling the point-extinguishing operation of the gas burner 8.
The burner head 80 of the gas burner 8 faces a burner opening (not shown) provided on the upper surface of the gas stove 7, and the cooking container P is placed above the burner head 80.

In addition, a temperature sensor 85 that detects the temperature of the cooking container P is provided at the upper center of the burner head 80.
The temperature sensor 85 is obtained by covering the thermistor 85a with a cylindrical box-shaped sensor cover 85b having high thermal conductivity. When the cooking container P is placed above the burner head 80, the upper surface of the sensor cover 85b is It is comprised so that the bottom face of the cooking container P may be pressed. The thermistor 85a is fixed in contact with the inner upper part of the sensor cover 85b and is electrically connected to the control circuit 9.

Although not shown, the control circuit 9 includes a point fire extinguishing circuit that executes ignition and fire extinguishing operations of the gas burner 8 in conjunction with the operation of the point fire extinguishing button 73, and the detected temperature T of the temperature sensor 85 is a predetermined overheated temperature ( For example, an overheating temperature determination circuit that determines whether or not the temperature has reached 250 ° C., the detected temperature T of the temperature sensor 85 within a preset determination time (for example, 2 minutes) is a reference temperature (for example, 80 ° C.). A sensor monitoring circuit for determining whether or not it has risen up to a) is incorporated.
In this case, as shown in the flow chart of FIG. 5, when the above-mentioned point-extinguishing button 73 is pressed, the above-mentioned point-extinguishing circuit opens a solenoid valve (not shown) to supply gas to the burner head 80 and is not shown. A high voltage is applied to the ignition electrode to ignite the gas burner 8.

  In addition, the measurement time of a timer (not shown) is reset at the same time as the gas burner 8 is ignited, and whether the detected temperature T of the temperature sensor 85 is lower than the reference temperature (here, 80 ° C.) by the sensor monitoring circuit described above. To monitor.

  Thereafter, when the detected temperature T becomes equal to or higher than the reference temperature within the determination time (here, 2 minutes), the detected temperature T of the temperature sensor 85 is then set to the excessive temperature (here, 250 ° C.). Monitor whether it has been reached. When the detected temperature T reaches the above excessive temperature, the solenoid valve (not shown) is closed and the gas burner 8 is extinguished.

  Therefore, for example, even when cooking oil is continuously heated from room temperature, the gas burner 8 is automatically extinguished if the detected temperature T reaches the excessive temperature (see graph C2 in FIG. 6). The cooking oil can be prevented from being overheated.

  On the other hand, even if the gas burner 8 is ignited, if the detected temperature T is lower than the reference temperature, a timer (not shown) incorporated in the sensor monitoring circuit is operated, and the state of being lower than the reference temperature is determined as a determination time (here Then, it is monitored whether or not to continue until 2 minutes).

And when the state below the said reference temperature continues until determination time (refer graph CN of FIG. 6), the solenoid valve which is not shown in figure is closed and the gas burner 8 is extinguished.
That is, when the detected temperature T does not rise to the reference temperature before the determination time elapses after the gas burner 8 is ignited, the upper surface of the sensor cover 85b is not securely in contact with the bottom surface of the cooking container P, or Since there is a possibility that the thermistor 85a has fallen off from the inside of the sensor cover 85b, the gas burner 8 is extinguished and heating of the cooking container P is stopped.
Thereby, it is possible to prevent the gas stove 7 from being continuously used in a state where the temperature sensor 85 does not normally detect the bottom surface temperature of the cooking container P.
Japanese Patent Application Laid-Open No. 06-307643

  However, for example, when cooking a food having a low temperature such as a refrigerated curry and relatively difficult to pass through, the detected temperature T does not rise to the reference temperature within the determination time (graph C3 in FIG. 6). In this case, in the above-described conventional apparatus, there is a problem that the gas burner 8 is extinguished because it is determined that the sensor is abnormal even though the temperature sensor 85 normally detects the bottom surface temperature of the cooking container P. It was.

The present invention has been made in view of such points,
“A heat source for heating the cooking container, a temperature sensor for detecting the temperature of the cooking container, a sensor monitoring means for determining whether the temperature sensor is not normally detecting the temperature of the cooking container, or a sensor, In the cooking device having a heating control means for stopping the heating operation of the heat source when the monitoring means determines that the sensor is abnormal, the heating cooker is easy to use by improving the accuracy of determining the sensor abnormality. It is an issue to provide.

The technical means of the invention according to claim 1 for solving the above-mentioned problem is as follows:
“The sensor monitoring means determines that a state in which the temperature detected by the temperature sensor is lower than a predetermined reference temperature and the temperature rise value per predetermined time of the detected temperature is lower than a predetermined reference change amount is set in advance. It is characterized in that it is determined that the sensor is abnormal when the operation continues.
In this case, if the temperature detected by the temperature sensor is less than the reference temperature and the temperature rise value per predetermined time is also less than the reference change amount during the preset determination time, the temperature sensor normally adjusts the temperature of the cooking container. It is determined that the sensor abnormality has not been detected, and the heating operation of the heat source is stopped.

  On the other hand, if the detected temperature of the temperature sensor reaches the reference temperature within the determination time, it is determined that the temperature sensor is normally detecting the temperature of the cooking container, and the heating operation of the heat source is continued. Therefore, for example, even in the case of heating cooked food that is already in a state where the temperature is already high and hardly changes in temperature even when heating is started, such as when reheating boiling water, the detected temperature is higher than the reference temperature. If so, it is determined that the temperature sensor is normally detecting the temperature of the cooking utensil.

  Further, according to the above technical means, if the detected temperature shows an increase of the reference change amount or more within the determination time, it is determined that the temperature sensor is normally detecting the temperature of the cooking container, and the heating operation of the heat source is performed. Will continue. Therefore, for example, even when cooking food that is low in temperature and relatively difficult to pass through, such as when reheating a refrigerated curry, the temperature change of the cooking container that rises relatively slowly It is determined that the temperature sensor normally detects the temperature of the cooking container. As a result, the possibility of erroneous determination as sensor abnormality is reduced.

The technical means of the invention according to claim 2 is:
In claim 1,
“Mode switching means for extending the determination time in the sensor monitoring means to a preset time;
A switching operation unit for instructing an extension operation of the mode switching means ”.
For example, when cooking a food that is low in temperature and extremely difficult to pass through, such as when cooking frozen udon noodles, the temperature of the cooking container rises until a relatively long time has passed since the start of heating. Since the temperature does not reach the predetermined reference temperature within the set determination time, the temperature rise value per predetermined time may be smaller than the predetermined reference change amount.

  However, according to the above technical means, by operating the switching operation unit, the determination time of the sensor abnormality is extended to a preset time, so that the temperature is low and the food is very difficult to pass through. It is possible to extend the sensor abnormality determination time. Therefore, the possibility of erroneous determination that the sensor is abnormal is further reduced.

Since the present invention has the above configuration, the present invention has the following specific effects.
In the invention according to claim 1, by determining sensor abnormality from the plurality of conditions described above, the possibility of erroneous determination as sensor abnormality is reduced, that is, the accuracy of determination of sensor abnormality is improved, so that the temperature sensor is normal. In spite of detecting the temperature of the cooking container, it is difficult to cause a problem that the heating operation of the heat source is stopped. Thereby, a user-friendly cooking device can be provided.

  In the invention according to claim 2, since the function of extending the determination time in accordance with the cooked food that is low in temperature and extremely difficult to pass through heat is provided, the possibility of erroneous determination as a sensor abnormality is further reduced. It is possible to provide a better cooking device.

Next, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram of a gas stove 1 exemplified as a heating cooker according to an embodiment of the present invention, and FIG. 2 is an operation flowchart showing a sensor abnormality determination operation of the gas stove 1. Details of each part will be described below.

As shown in FIG. 1, the gas stove 1 controls a gas burner 2 that heats a cooking container P such as a pan or a frying pan placed on the upper portion of the casing 10 by the combustion heat of gas, and a point-extinguishing operation of the gas burner 2. And a control circuit 3.
Also, a burner opening 11 is formed on the upper surface of the casing 10, and five virtues 12 for supporting the cooking container P are disposed on the periphery of the burner opening 11.

  On the other hand, on the front surface of the casing 10, a point fire button 13 for igniting and extinguishing the gas burner 2, a sensor release button 14 for switching on / off of a sensor release mode described later, and a gas amount adjusting valve described later. A heating power adjusting lever 16 for adjusting the opening degree of 26 is provided.

  Further, in the casing 10, there are an ignition switch 13a that switches between an on state and an off state each time the point fire extinguishing button 13 is pressed, and a release switch 14a that is turned on while the sensor release button 14 is being pressed. Is incorporated.

The gas burner 2 is accommodated in the casing 10 with the burner head 20 facing the burner opening 11.
The burner head 20 is connected to a gas passage 200 connected to the gas pipe G. In the gas passage 200, an electromagnetic valve 21 and a gas amount adjusting valve 26 are arranged in this order from the upstream side.

The solenoid valve 21 includes a spring 21a that biases the valve body (not shown) in the closing direction, and a solenoid 21b that maintains an open state of the valve body by energization. By performing the ignition operation, the valve body is configured to open against the urging force of the spring 21a.
The gas amount adjusting valve 26 is mechanically connected to the thermal power adjusting lever 16 and is configured such that the opening degree changes in accordance with the operation position of the thermal power adjusting lever 16.

  Further, in the vicinity of the flame hole 22 formed on the peripheral surface of the burner head 20, there are an ignition electrode 23 that performs a spark discharge when a high voltage is applied from an igniter (not shown), and a combustion flame that is ejected from the flame hole 22. A flame sensor 24 for detection is provided.

Furthermore, a temperature sensor 25 that detects the temperature of the cooking container P placed on the virtues 12 is provided in the center of the burner head 20.
The “gas burner 2” corresponds to the “heat source” as the invention specific matter of claim 1 described above.

  The temperature sensor 25 includes a thermistor 25a that changes electric resistance in accordance with the temperature of the contact surface, a cylindrical box-shaped sensor cover 25b that covers the thermistor 25a, and a support shaft 25c that supports the sensor cover 25b in a state in which the sensor cover 25b can move up and down. Thus, when the cooking container P is placed on the virtues 12, the upper surface of the sensor cover 25b is pressed against the bottom surface of the cooking container P by a restoring force of a spring (not shown).

The sensor cover 25b is made of a material having high thermal conductivity, and the thermistor 25a is fixed in contact with the inner upper center of the sensor cover 25b. Therefore, the thermistor 25a detects the heat of the bottom surface of the cooking container P conducted to the inner upper part of the sensor cover 25b, and changes the electrical resistance.
The thermistor 25a, ignition switch 13a, release switch 14a, solenoid 21b, ignition electrode 23, and flame sensor 24 are electrically connected to the control circuit 3.

  In addition to the point-extinguishing circuit 31 that ignites or extinguishes the gas burner 2 in conjunction with the operation of the point-extinguishing button 13, the control circuit 3 includes a temperature T detected by the temperature sensor 25 derived from the electrical resistance of the thermistor 25a. An excessive temperature rise determination circuit 32 for determining whether or not the temperature rise (for example, 250 ° C.) has been reached. Sensor monitoring circuit 33 for determining whether or not a state in which a temperature rise value per second) is less than a reference change amount (for example, 6 ° C.) has been maintained for a predetermined determination time (for example, 2 minutes), and sensor release A mode switching circuit 34 for switching on / off setting of a sensor release mode, which will be described later in conjunction with the operation of the button 14, and a microcomputer storing a program for linking these circuits. Computer and (not shown) is incorporated.

  The “point extinguishing circuit 31” corresponds to the “heating control means” as the invention specific matter of the first claim, and the “sensor monitoring circuit 33” is the invention specific matter of the first claim. Corresponds to “sensor monitoring means”. Further, the “sensor release button 14” corresponds to the “switching operation unit” as the invention specifying matter of claim 2 described above, and the “mode switching circuit 34” is the invention specifying matter of claim 2 described above. Corresponds to “mode switching means”.

Further, although not shown, the control circuit 3 includes a timer that measures the passage of time since the gas burner 2 was ignited, and a count number each time the timer measurement time advances by a unit time (for example, 7.5 seconds). A counter that increments n by 1, a first memory that stores the detected temperature T _n of the temperature sensor 25 per unit time, and a second memory that stores an elapsed time A from when the gas burner 2 is ignited are incorporated. It is.

[Actual sensor abnormality judgment operation]
Next, the sensor abnormality determination operation by the control circuit 3 will be described according to the operation flowchart of FIG.
First, when the fire extinguishing button 13 is pressed, the valve body of the electromagnetic valve 21 is opened against the biasing force of the spring 21a, gas is supplied from the gas pipe G to the burner head 20, and the ignition switch 13a is turned on. It becomes a state. When the ignition switch 13a is turned on, a high voltage is applied from the igniter (not shown) to the ignition electrode 23 by the point fire extinguishing circuit 31 to ignite the gas burner 2 and then energize the solenoid 21b to open the valve body. The state is maintained (ST1-2).

When the flame sensor 24 detects the combustion flame of the gas burner 2, the count number n of a counter (not shown) and the elapsed time A stored in the second memory are reset to “0” and a timer (not shown) is activated. After that, it is determined whether or not the detected temperature T ₀ when the gas burner 2 is ignited is equal to or higher than the reference temperature (here, 70 ° C.) (ST 3 to 4).

As a result, if the detected temperature T ₀ when the gas burner 2 is ignited is already equal to or higher than the reference temperature “70 ° C.”, for example, as in the case of reheating hot water (see graph C1 in FIG. 3), It is determined that the temperature of the bottom surface of the cooking container P that has reached a high temperature is normally detected by the temperature sensor 25 (normal state), and the point-extinguishing button 13 is pressed again by the point-extinguishing circuit 31, and the ignition switch 13a. Is turned off, or whether or not the detected temperature T has reached the overheated temperature (here, 250 ° C.) is monitored by the overheated temperature determination circuit 32 (ST5 to ST6).

  When the ignition switch 13a is turned off, or when the detected temperature T of the temperature sensor 25 reaches the overheated temperature “250 ° C.”, the energization of the solenoid 21b is interrupted and the spring 21a is turned off. The valve body of the electromagnetic valve 21 is closed by the urging force, and the supply of gas to the burner head 20 is stopped (ST7). Thereby, since the gas burner 2 is extinguished, it is possible to prevent the food in the cooking container P from being overheated.

On the other hand, if the detected temperature T ₀ at the 0th count is lower than the reference temperature “70 ° C.” in step ST4, the operations after step ST8 are executed.
Specifically, first, the detected temperature T ₀ is stored in a first memory (not shown), and then the sensor release button 14 is pressed for a long time by the mode switching circuit 34 and the release switch 14a is operated for a certain time (here, 3 seconds). ) Whether the timer is maintained in the ON state and whether the measurement time of the timer has advanced by a predetermined unit time (here, 7.5 seconds) are monitored by the sensor monitoring circuit 33 (ST8 to 10).

If the measured time of the timer advances by the unit time “7.5 seconds”, the count number n of the counter is increased by 1, and the detected temperature T _n when the measured time of the timer advances by the unit time, that is, The sensor monitoring circuit 33 determines whether or not the detected temperature T _n of the temperature sensor 25 of the nth count is equal to or higher than the reference temperature “70 ° C.” (ST11 to 12).

As a result, if the detected temperature T _n is equal to or higher than the reference temperature “70 ° C.”, the temperature sensor 25 normally detects the bottom surface temperature of the cooking container P heated by the gas burner 2 and becoming high (normal State), and the operations of steps ST5 to ST7 described above are executed.

On the other hand, if the detected temperature T _n is lower than the reference temperature “70 ° C.” in step ST12, the detected temperature T _n is stored in a first memory (not shown), and then the count number n is a first predetermined value. It is determined whether or not (here, 2) or more, that is, whether or not a first predetermined time (here, 15 seconds) or more has elapsed since the gas burner 2 was ignited (ST13 to 14).
At this time, if the count number n has not reached the first predetermined value “2”, the above-described operations of steps ST9 to ST14 are executed again.

In step ST14, if the count number n is the first predetermined value "2" or more, the first predetermined value number of times from the detection temperature T _n of the point (2 times) before the detection temperature T ₍ A value obtained by subtracting _n−2), that is, a temperature rise value per first predetermined time (15 seconds) (hereinafter referred to as “section temperature rise value”) T _n −T _(n−2) is set in advance. The sensor monitoring circuit 33 determines whether or not the first reference change amount (here, 3 ° C.) or more (ST15).

As a result, for example, as in the case where cooking oil is heated from room temperature (see graph C2 in FIG. 3), the above-described section temperature rise value T _n −T _(n−2) after the gas burner 2 is ignited is the first reference. If the change amount is “3 ° C.” or more, it is determined that the temperature sensor 25 is normally detecting the bottom temperature of the cooking container P that is heated by the gas burner 2 and is rising (normal state), and is described above. Steps ST5 to ST7 are performed.

In addition, when the refrigerated curry is reheated (see graph C3 in FIG. 3), or when the temperature of the cooking container P is suddenly lowered (not shown) by introducing a low-temperature food during cooking. If the temperature rise value T _n −T _(n−2) after the ignition of the gas burner 2 is equal to or greater than the first reference change amount “3 ° C.”, it is determined that the temperature sensor 25 is in a normal state. Then, the above-described operations of steps ST5 to ST7 are executed.

On the other hand, if the section temperature rise value T _n −T _(n−2) is less than the first reference change amount “3 ° C.” in step ST15, then the count number n is set to the second predetermined value (here Then, it is determined by the sensor monitoring circuit 33 whether or not it is 8) or more, that is, whether or not a second predetermined time (in this case, 60 seconds) has elapsed since the gas burner 2 was ignited (ST16). .
At this time, if the count number n has not reached the second predetermined value “8”, the above-described operations of steps ST9 to ST16 are executed again.

In step ST16, if the count number n is equal to or greater than the second predetermined value “8”, after confirming that the count number n is the second predetermined value “8”, the detected temperature at this time point A value obtained by subtracting the detected temperature T ₀ before the second predetermined number of times (eight times) from T ₈ , that is, a temperature increase value per second predetermined time (60 seconds) (hereinafter referred to as “cumulative temperature increase value”). _{"hereinafter)} T 8 -T ₀ is the second reference change amount set in advance (here, it is determined whether the 6 ° C.) or higher (ST17~18).

As a result, if the cumulative temperature rise value T ₈ -T ₀ after the gas burner 2 is ignited is equal to or greater than the second reference change amount “6 ° C.”, the bottom surface of the cooking container P that has started to rise as a result of being heated by the gas burner 2. It is determined that the temperature sensor 25 is normally detecting the temperature (normal state), and the above-described operations of steps ST5 to ST7 are executed.

On the other hand, if the cumulative temperature increase value T ₈ -T ₀ is less than the second reference change amount “6 ° C.” in step ST18, the elapsed time A stored in the second memory is increased by “1 minute”. At the same time, after confirming that the sensor release mode, which will be described later, is not set to ON, it is determined whether or not the elapsed time A has reached the determination time “2 minutes” (ST19 to 21).
At this time, if the elapsed time A has not reached the determination time “2 minutes”, the above-described operations after step ST9 are executed again.

In the step ST16 and ST17, the count number n is confirmed that becomes "9" exceeds the second predetermined value, detecting the count 9th detected temperature T ₉ counts first temperature T and at the same time replacing stored as ₁ to the second memory to replace stores a count eighth detection temperature T ₈ as a detection temperature T ₀ of the count 0-th to second memory. Then, the count number n is reset to “1”, and the operations after step ST9 are executed again (ST22 to ST23).

That is, until the elapsed time A reaches the determination time “2 minutes”, whether or not the detected temperature T _n is equal to or higher than the reference temperature “70 ° C.” (ST12), the zone temperature rise value T _n −T _{(n−2). )} Is greater than or equal to the first reference change amount “3 ° C.” (ST15), and whether the cumulative temperature rise value T ₈ -T ₀ is greater than or equal to the second reference change amount “6 ° C.” (ST18). The determination operation is repeated by the sensor monitoring circuit 33.

  In the meantime, if any one of the above-mentioned conditions of step ST12, ST15 or ST18 is satisfied, the temperature sensor 25 is determined to be in the above-described normal state, and the operations of steps ST5 to ST7 are executed.

On the other hand, when none of the above-described conditions of steps ST12, ST15, and ST18 is satisfied before the elapsed time A reaches the determination time “2 minutes” (see graph CN in FIG. 3), the sensor cover 25b. Is fixed to the support shaft 25c, so that the upper surface of the sensor cover 25b is not securely in contact with the bottom surface of the cooking container P, or vibrations when the gas stove 1 is transported and the cooking container P to the temperature sensor 25. Since the thermistor 25a may have fallen from the inner side of the sensor cover 25b due to the impact at the time of collision, the thermal deformation of the fixing member that fixes the thermistor 25a to the inner upper surface of the sensor cover 25b, the point-extinguishing circuit 31 To extinguish the gas burner 2 and stop heating the cooking container P.
Thereby, it is possible to prevent the gas stove 1 from being continuously used in a sensor abnormal state in which the temperature sensor 25 does not normally detect the bottom surface temperature of the cooking container P.

However, for example, as in the case where the frozen udon is cooked (see graph C4 in FIG. 3), the detection is performed until the elapsed time A from when the gas burner 2 is ignited reaches the determination time “2 minutes”. The temperature T _n is less than the reference temperature “70 ° C.”, the section temperature rise value T _n −T _(n−2) after the gas burner 2 is ignited is also less than the first reference change amount “3 ° C.”, and the cumulative temperature rise value If T ₈ -T _{0 is} also less than the second reference variation “6 ° C.”, it is determined that the temperature sensor 25 does not normally detect the bottom surface temperature of the cooking container P as described above, and the gas burner 2 is extinguished. There is a possibility that.

  Therefore, when cooking a dish whose temperature does not rise easily even when heated, the user manually presses the sensor release button 14 for a certain period of time (here, 3 seconds) to set the sensor release mode to ON. To do.

  Specifically, in step ST9, when the sensor release button 14 is pressed and held and the release switch 14a is kept on for a certain period of time, the mode switching circuit 34 determines whether or not the sensor is abnormal. After the sensor release mode for extending the determination time (2 minutes) set as the time to be set to a preset time (here, 10 minutes) is set to ON, the operations after step ST10 are executed (ST24).

Then, when it is confirmed in step ST20 that the sensor release mode is on, it is determined whether or not the elapsed time A from when the gas burner 2 is ignited has reached the extended determination time “10 minutes”. If the elapsed time A has not reached the extended determination time “10 minutes”, the above-described operations after step ST9 are executed again (ST25).
That is, the determination operation of steps ST12, ST15, and ST18 described above is repeated by the sensor monitoring circuit 33 until the elapsed time A reaches the extended determination time “10 minutes”.

In the meantime, if any one of the above-mentioned conditions of step ST12, ST15 or ST18 is satisfied (as shown in the graph C4 in FIG. 3), when the 480 seconds have elapsed since the gas burner 2 was ignited, When the value T ₈ -T ₀ is equal to or greater than the second reference change amount “6 ° C.”), the temperature sensor 25 determines that it is in the normal state described above, and executes the operations of steps ST5 to ST7.

On the other hand, if none of the above-described conditions of steps ST12, ST15, and ST18 is satisfied before the elapsed time A reaches the extended determination time “10 minutes”, the fire extinguishing circuit 31 forces The gas burner 2 is extinguished and heating of the cooking container P is stopped.
Thereby, it is possible to prevent the gas stove 1 from being continuously used in the sensor abnormal state.

Although not shown, when the burner extinguishing operation in step ST7 is executed and the gas burner 2 is extinguished, the setting of the sensor release mode is returned to off.
In this case, even if the detected temperature T _n of the temperature sensor 25 does not reach the reference temperature within the determination time, the section temperature rise value T _n −T _(n−2) is equal to or greater than the first reference change amount, or is cumulative. satisfies the temperature increase value T ₈ -T ₀ is the second reference change amount or more of one of the conditions, it is determined that the temperature sensor 25 is normal.

  That is, even if the detected temperature T of the temperature sensor 25 does not reach the reference temperature within the determination time, if the detected temperature T shows an increase over the reference change amount within the determination time, the temperature sensor 25 is normally operated. It is determined that the bottom surface temperature of the cooking container P is detected, and the combustion operation of the gas burner 2 is continued.

  As a result, since the possibility of erroneous determination that the sensor is abnormal is reduced, the combustion operation of the gas burner 2 is stopped even though the temperature sensor 25 normally detects the bottom surface temperature of the cooking container. It is possible to provide an easy-to-use gas stove 1 that does not easily cause such problems.

  If the sensor release button 14 is pressed and held, the determination time “2 minutes” is extended to a preset time “10 minutes”. It is possible to extend the sensor abnormality determination time according to the object.

  Accordingly, since the possibility of erroneous determination that the sensor is abnormal is further reduced, the combustion operation of the gas burner 2 is stopped even though the temperature sensor 25 normally detects the bottom surface temperature of the cooking container. Thus, it is possible to provide a gas stove 1 that is less likely to cause such problems and is more convenient to use.

[Others]
In the above embodiment, determines sensor abnormality three conditions detected temperature _{T n,} the interval the temperature increase value _{T n -T (n-2)} and the cumulative temperature rise _T 8 -T ₀ of the temperature sensor 25 Although described, the determination may be made based on two conditions of the detected temperature T _n and the section temperature increase value T _n −T _(n−2) , or the detected temperature T _n and the accumulated temperature increase value T ₈ −T _0. You may determine from these two conditions.

  Although the heating cooker in the said embodiment illustrated and demonstrated the gas stove 1 which heats the cooking container P with the combustion heat of gas, if it was provided with the temperature sensor for detecting the temperature of a cooking container, An electromagnetic induction type or electric heater type stove may be used, or a rice cooker or hot plate may be used.

1 is a schematic configuration diagram of a gas stove 1 according to an embodiment of the present invention. Operation flowchart showing sensor abnormality determination operation of gas stove 1 according to the embodiment of the present invention. The graph which shows the detected temperature change of the temperature sensor 25 of the gas stove 1 which concerns on embodiment of this invention. Schematic configuration diagram of a conventional gas stove 7 Operation flowchart showing sensor abnormality determination operation of the conventional gas stove 7 The graph which shows the detection temperature change of the temperature sensor 85 of the conventional gas stove 7

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Cooking device 2 ... Heat source 25 ... Temperature sensor 31 ... Heating control means 33 ... Sensor monitoring means P ... Cooking container

Claims (2)

A heat source for heating the cooking container, a temperature sensor for detecting the temperature of the cooking container, a sensor monitoring means for determining whether or not the temperature sensor is not normally detecting the temperature of the cooking container, and sensor monitoring In a heating cooker comprising heating control means for stopping the heating operation of the heat source when the sensor is determined to be abnormal by the means,
The sensor monitoring means is in a state in which the temperature detected by the temperature sensor is lower than a predetermined reference temperature and the temperature rise value per predetermined time of the detected temperature is lower than a predetermined reference change amount until a predetermined determination time. A cooking device characterized by determining that the sensor is abnormal when the sensor is continued. The heating cooker according to claim 1, wherein
Mode switching means for extending the determination time in the sensor monitoring means to a preset time;
A cooking device, comprising: a switching operation unit that instructs an extension operation of the mode switching means.

Images