JP2008267703A - Cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker capable of grasping deviation of a detected temperature by a temperature detecting means and more accurately detecting failure of the temperature detecting means. <P>SOLUTION: When a high heat power burner and a standard heat burner are both in a turned off state and sufficient time has passed for the detected temperatures of thermistors provided to each of the two burners to become room temperatures, the detected temperatures of the two thermistors are compared (S7). When the temperature difference between the detected temperatures is within a predetermined range (S7: No), the two thermistors are determined to be normal. On the other hand, when the temperature difference is outside the predetermined range (S7: Yes), at least trouble of one thermistor is determined (S8). Thereby, failure of the thermistors are accurately detected. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a cooking device, and more particularly to a cooking device provided with a temperature detecting means for detecting the temperature of a cooking container.

Conventionally, in order to prevent a tempura fire or the like, the bottom temperature of the cooking container heated by a heating means such as a gas burner is detected by the temperature detecting means, and when the detected temperature reaches a set temperature, the heating by the heating means is stopped. A cooking device is known. In this heating cooking apparatus, a temperature sensor with a built-in thermistor is brought into contact with the bottom surface of the cooking container placed on Gotoku. The temperature detected by the thermistor is monitored, and when the detected temperature reaches the set temperature, the electromagnetic valve provided in the gas supply path to the burner is forcibly closed to automatically digest. In order to detect a short-circuit failure of the thermistor, a cooking device in which a current fuse is connected in series with the thermistor has been proposed (see, for example, Patent Document 1). According to this cooking device, when the thermistor is short-circuited, the current fuse is blown to detect a failure. There has also been proposed a cooking device that detects a disconnection failure when the electrical resistance of the thermistor exceeds a predetermined value (see, for example, Patent Document 2).
JP-A-9-33047 JP-A-9-210808

  However, in such a conventional cooking apparatus, the only method for detecting a thermistor failure is to detect an extreme failure such as a short-circuit failure and a disconnection failure, and the failure is detected by grasping a slight deviation in the detected temperature. There was a problem that it was not possible.

  The present invention has been made to solve the above-described problem, and provides a cooking apparatus that can detect a temperature detection unit failure more accurately by grasping a difference in temperature detected by the temperature detection unit. For the purpose.

  In order to achieve the above object, a heating cooking apparatus according to a first aspect of the present invention comprises a heating means for heating an object to be cooked, and a temperature detecting means for detecting the temperature of the object to be cooked heated by the heating means. A heating cooking device comprising a plurality of sets, a heating state determination unit that determines whether or not heating by the heating unit is performed, and heating by the heating unit is not performed by the heating state determination unit And a failure detection unit that determines that the temperature detection unit has failed when a difference in temperature detected by the plurality of temperature detection units is out of a predetermined range.

  In addition to the configuration of the invention according to claim 1, the cooking device of the invention according to claim 2 is a predetermined time after the heating state determination means determines that heating by the heating means is not performed. An elapsed time measuring means for measuring the temperature, and the failure detecting means fails due to a difference in temperature detected by the plurality of temperature detecting means when a predetermined time is measured by the elapsed time measuring means. It is characterized by determining whether or not.

  Moreover, in addition to the structure of the invention of Claim 1 or 2, the heating cooking device of the invention which concerns on Claim 3 gives the instruction | indication for the said heating state judgment means to switch the action | operation of the said heating means, and a stop. It is characterized in that it is determined whether or not heating by the heating means is performed based on at least one of a switch state and an output of a thermocouple that detects whether or not the heating means is operating.

  In the cooking device according to the first aspect of the invention, when the heating means is not heated, the temperature detected by the plurality of temperature detecting means should all approach the room temperature. It is possible to determine whether or not at least one of the plurality of temperature detecting means is out of order. Thereby, not only an extreme failure of the temperature detection means such as a short circuit failure and a disconnection failure, but also a deviation of the detection temperature can be grasped, so that the failure of the temperature detection means can be detected more accurately.

  In addition, in the heating cooking apparatus of the invention according to claim 2, in addition to the effect of the invention of claim 1, since the failure detection is performed after measuring a predetermined time after the heating by the heating means is completed, The influence of the temperature change can be reduced and the temperature detecting means can be accurately failed.

  In addition, in the cooking device of the invention according to claim 3, in addition to the effect of the invention according to claim 1 or 2, the state of the switch for instructing switching between the operation and stop of the heating means, and the heating means are activated. It is possible to easily determine whether or not heating by the heating means is performed by at least one of the outputs of the thermocouple that detects whether or not the heating is performed.

  Hereinafter, a stove 1 according to an embodiment of the present invention will be described with reference to the drawings. 1 is a plan view of the stove 1, FIG. 2 is a front view of the stove 1, and FIG. 3 is a block diagram showing an electrical configuration of the stove 1. As shown in FIG. FIG. 4 is a diagram showing an example of a change in detected temperature by the first thermistor 7 and the second thermistor 8 when the first thermistor 7 has failed. FIG. 5 shows the thermistor by the microcomputer control circuit 40. It is a flowchart which shows a failure detection process.

  The stove 1 of the present embodiment compares the detected temperatures of the two thermistors 7 and 8 that should detect the room temperature after the heating by the burner is completed, and if the temperature difference is outside the predetermined range, at least one of them Judge that the thermistor has failed. As a result, the failure of the thermistors 7 and 8 can be accurately detected.

  First, a schematic configuration of the stove 1 will be described. As shown in FIGS. 1 and 2, a top plate 2 having a substantially rectangular plate shape is provided on the top surface of the stove 1, and a circular opening 3 is formed in a right half portion of the top plate 2. A circular opening 4 is formed in the left half portion. A standard burner 5 is provided inside the opening 4, and a strong heating power burner 6 is provided inside the opening 3. The openings 4 and 3 are provided with virtues 11 and 12 so as to cover the outer peripheries of the standard burner 5 and the high heat burner 6, and cooking pots (not shown) are placed on the upper portions of the virtues 11 and 12. Placed.

  In addition, thermocouples 19 and 20 are provided in the vicinity of the standard burner 5 and the high thermal power burner 6 to detect that the burners 5 and 6 are in a combustion state by generating an electromotive force by heating the combustion flame. To do. A first thermistor 7 is provided at the center of the standard burner 5, and a second thermistor 8 is provided at the center of the high thermal power burner 6. These thermistors 7 and 8 detect the bottom temperature of the pot by abutting against the bottom of the cooking pot placed on the virtues 11 and 12. That is, since the temperature of the cooking object in the cooking pan cannot be directly detected, the temperature of the cooking object in the cooking pan is estimated by detecting the pan bottom temperature. In addition, a grill 15 is provided in the center of the inside of the stove 1, and a grill burner (not shown) for heating an object to be cooked is provided in a grill box (not shown) of the grill 15.

  Further, a grill exhaust port (not shown) of the grill 15 is provided behind the top plate 2, and the exhaust port covers 13 and 14 for blocking the rise of flame from the grill exhaust port. Is detachably provided. The exhaust port covers 13 and 14 are provided with a plurality of exhaust holes 13a and 14a, respectively.

  As shown in FIG. 2, an operation switch 21 for igniting the standard burner 5 is provided on the lower left side of the front surface facing the user of the stove 1. In addition, an operation switch 22 for igniting the high thermal power burner 6 and an operation switch 23 for igniting the grill burner (not shown) are provided side by side at the lower part on the right side across the grill 15. Further, a heating power adjustment lever 25 capable of manually adjusting the heating power of the standard burner 5 is provided above the operation switch 21, and a heating power adjustment lever capable of manually adjusting the heating power of the strong heating power burner 6 is provided above the operation switch 22. 26 is provided, and on the upper side of the operation switch 23, a heating power adjusting lever 27 capable of manually adjusting the heating power of the grill burner (not shown) is provided. In addition, a battery box 29 in which a dry battery is installed and a speaker 50 (see FIG. 3) for sounding a buzzer are provided at the left end of the front surface of the stove 1.

  Further, the standard burner 5, the strong burner 6, and the grill burner of the stove 1 are each provided with an igniter 35 (see FIG. 3) for igniting each burner. Further, the stove 1 is provided with a gas supply pipe (not shown) for supplying gas to each burner, and each gas supply pipe is inadvertently detected when a failure of the thermistors 7 and 8 is detected or due to spillage or the like. A safety valve 38 (see FIG. 3), which is an electromagnetic valve for cutting off the gas supply when the fire extinguishing is detected by the thermocouples 19 and 20, is provided. 1 and 2 correspond to the “heating means” of the present invention, and the first thermistor 7 and the second thermistor 8 correspond to the “temperature detection means”.

  Next, the electrical configuration of the stove 1 will be described. As shown in FIG. 3, the stove 1 includes a microcomputer control circuit 40 that performs thermal power control of various burners. The microcomputer control circuit 40 includes a CPU 40a, a ROM 40b, a RAM 40c, an I / O interface (not shown), and the like. The microcomputer control circuit 40 includes a power supply circuit 41 that supplies power to various circuits by a dry battery mounted in the battery box 29 (see FIG. 2), and switches that detect pressing of the operation switches 21, 22, and 23, respectively. An input circuit 42, a thermistor input circuit 43 for inputting detection signals output from the thermistors 7 and 8, an igniter circuit 45 for driving the igniters 35 of various burners, and a safety valve for controlling the opening and closing of each safety valve 38 A circuit 46, a thermocouple circuit 51 for detecting the electromotive force of the thermocouples 19 and 20, a voltage monitoring circuit 47 for monitoring the voltage of the power supplied from the power supply circuit 41, and a buzzer for outputting a buzzer from the speaker 50. The output circuit 48 and the nonvolatile memory circuit 4 which is a semiconductor memory capable of retaining stored contents even when the power supply from the power supply circuit 41 is cut off If, like are respectively connected. The power supply circuit 41 includes a microcomputer control circuit 40, a switch input circuit 42, a thermistor input circuit 43, an igniter circuit 45, a safety valve circuit 46, a thermocouple circuit 51, a voltage monitoring circuit 47, a buzzer output circuit 48, and a nonvolatile memory circuit 49. Etc., and power is supplied to each circuit.

  Next, a thermistor failure detection method in the stove 1 will be described by taking as an example a change in detected temperature by the two thermistors 7 and 8 when the first thermistor 7 has failed. In the example shown in FIG. 4, the first thermistor 7 has a failure that detects a temperature higher than the actual temperature. As shown in FIG. 4, the normal second thermistor 8 detects the room temperature at the time when the high thermal power burner 6 is ignited. Then, the temperature detected by the second thermistor 8 rises with time due to the combustion flame generated by the strong thermal burner 6. On the other hand, the failed first thermistor 7 continues to detect a temperature higher than room temperature until the standard burner 5 is ignited. Next, when the standard burner 5 is ignited, the temperature detected by the first thermistor 7 rises.

  When the high thermal power burner 6 is extinguished, the temperature detected by the second thermistor 8 decreases, and when the standard burner 5 is extinguished, the temperature detected by the first thermistor 7 also decreases. After a sufficient time has elapsed, the temperatures of the two thermistors 7 and 8 are both equal to the room temperature. However, in the example shown in FIG. 4, the first thermistor 7 is out of order. The time elapses without filling the temperature difference between the temperature detected by the two thermistors 8. Therefore, in the present embodiment, the time until the temperature of the two thermistors 7 and 8 becomes equal to the room temperature after both the strong heating burner 6 and the standard burner 5 are extinguished is measured. If the difference between the detected temperatures of the two thermistors 7 and 8 after the time measurement ends is outside the predetermined range, it is determined that at least one of the thermistors 7 and 8 has failed.

  Next, the thermistor failure detection process will be described. As shown in FIG. 5, when power supply to the microcomputer control circuit 40 is started by the power supply circuit 41, the thermistor failure detection process by the CPU 40a of the microcomputer control circuit 40 is started. First, it is determined whether or not the high thermal power burner 6 is in an ignition state (S1). This determination is made based on whether or not the operation switch 22 is on. If the operation switch 22 is off (S1: NO), it is determined whether or not the standard burner 5 is in an ignition state. Is performed (S2). When it is determined that the operation switch 21 is off and the standard burner 5 is not in an ignition state (S2: NO), the process returns to the determination of S1, and one of the two burners 5 and 6 is in an ignition state. These determinations are repeatedly performed.

  Next, when one of the operation switches 21 and 22 is turned on and it is determined that the ignition state is set (S1: YES or S2: YES), it is determined whether or not the strong heating burner 6 is in a digested state. Is performed (S3). When the operation switch 22 is turned on and it is determined that the high thermal burner 6 is in an ignition state (S3: NO), this determination is repeatedly performed until the digestion state is reached. If it is determined that the high-burning power burner 6 is in the digested state (S3: YES), it is determined whether or not the standard burner 5 is in the digested state (S4). When it is determined that the operation switch 21 is on and the standard burner 5 is in an ignition state (S4: NO), the process returns to the determination of S3. On the other hand, when both the high thermal power burner 6 and the standard burner 5 are in a digested state (S4: YES), a process for starting measurement by a timer for a predetermined time (for example, 15 minutes) until failure detection is performed. Is performed (S5).

  If the time measurement by the timer has not ended (S6: NO), this determination is repeated. Here, although not shown in the flowchart, when at least one of the burners 5 and 6 is in the ignition state again, the process returns to the determination of S3. When the measurement of the predetermined time is completed (S6: YES), whether or not the difference between the temperature detected by the first thermistor 7 and the temperature detected by the second thermistor 8 is outside the predetermined range (for example, 10 ° C. A determination is made as to whether or not (S7). If it is within the predetermined range (S7: NO), it is determined that both the first thermistor 7 and the second thermistor 8 are normal, and the process directly returns to S1. On the other hand, if the temperature difference between the two thermistors 7 and 8 is outside the predetermined range (S7: YES), the nonvolatile memory circuit 49 indicates that at least one of the first thermistor 7 and the second thermistor 8 has failed. Stored (S8), the process returns to S1. When a failure of the thermistors 7 and 8 is detected, a buzzer is generated from the speaker 50 and a process for closing the safety valve 38 is performed to cut off the gas supply to each burner.

  In S1 to S4 of the flowchart shown in FIG. 5, the CPU 40a of the microcomputer control circuit 40 that determines whether or not the heating by the burners 5 and 6 is functioning as the “heating state determination means” of the present invention. In S6, the CPU 40a that determines whether or not the timer has expired functions as the “elapsed time measuring means” of the present invention. In S7, the CPU 40a that detects the failure of the thermistors 7 and 8 by determining whether or not the difference between the detected temperatures of the two thermistors 7 and 8 is outside the predetermined range allows the “failure detection means” of the present invention. Function as.

  As described above, in the stove 1 of the present embodiment, the predetermined time after both the strong heating burner 6 and the standard burner 5 are extinguished is measured, and the detected temperature of the first thermistor 7 after the time measurement ends and the first temperature The detected temperature of the two thermistor 8 is compared. The failure of the thermistors 7 and 8 can be detected by determining whether or not the temperature difference between the two detected temperatures is outside the predetermined range. Therefore, it is possible to grasp the deviation of the detected temperature by the thermistors 7 and 8 and more accurately detect the failure of the thermistors 7 and 8.

  In addition, the cooking apparatus of this invention is not limited to the stove 1 of the said embodiment, A various change is possible. For example, although the two thermistors 7 and 8 are disposed in the stove 1 of the present embodiment, the present invention can be applied to a cooking device in which three or more thermistors are disposed. . Further, in the present embodiment, the ignition state of the strong thermal burner 6 and the standard burner 5 is determined by turning on and off the operation switches 21 and 22, but whether or not electromotive force is generated by the thermocouples 19 and 20 is determined. Thus, the ignition state may be determined by using both the electromotive force of the thermocouples 19 and 20 and the on / off of the operation switches 21 and 22.

  The timing for performing the failure detection operation, the length of time measured after the burner is extinguished, the temperature difference serving as a reference for determining that there is a failure, and the like may be set as appropriate. Alternatively, the thermistor failure detection process may be terminated when the temperature detected by the thermistors 7 and 8 falls within a predetermined range. Further, the failure detection may be performed by combining the failure detection method of the thermistor according to the present invention with the conventional failure detection method of detecting a short circuit failure or a disconnection failure.

  The heating cooking apparatus of the present invention is applicable to a heating cooking apparatus that includes a thermistor capable of measuring the heating temperature of an object to be cooked and controls the combustion flame by a burner based on the temperature detected by the thermistor.

1 is a plan view of a stove 1. FIG. It is a front view of the stove 1. It is a block diagram which shows the electric constitution of the stove. It is the figure which showed an example of the change of the detected temperature by the 1st thermistor 7 and the 2nd thermistor 8 when the 1st thermistor 7 is out of order. 4 is a flowchart showing a thermistor failure detection process by a microcomputer control circuit 40.

Explanation of symbols

1 Stove 5 Standard Burner 6 High Thermal Burner 7 First Thermistor 8 Second Thermistor 19, 20 Thermocouple 21, 22 Operation Switch 40 Microcomputer Control Circuit 40a CPU

Claims (3)

A heating cooking apparatus comprising a plurality of sets of heating means for heating the food to be cooked and temperature detection means for detecting the temperature of the food to be cooked heated by the heating means,
Heating state determination means for determining whether heating by the heating means is performed;
If the difference between the temperatures detected by the plurality of temperature detecting means is outside a predetermined range when the heating state determining means determines that heating by the heating means is not performed, the temperature detecting means fails. A cooking device, comprising: a failure detection unit that determines that the device is operating. Elapsed time measuring means for measuring a predetermined time after it is determined by the heating state determining means that heating by the heating means is not performed,
The failure detection means determines whether or not the temperature detection means has failed based on a difference in temperature detected by the plurality of temperature detection means when the predetermined time is measured by the elapsed time measurement means. The cooking device according to claim 1, wherein the cooking device is a cooking device.   The heating state determination means is based on at least one of the state of a switch that gives an instruction for switching between the operation and stop of the heating means, and the output of a thermocouple that detects whether or not the heating means is operating. It is judged whether the heating by the said heating means is performed, The heat cooking apparatus of Claim 1 or 2 characterized by the above-mentioned.

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