JP2012094262A - Heating cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heating cooker that can securely stop heating to take safety into account such that oscillation of an inverter circuit will not continue due to some malfunction in a control circuit.SOLUTION: A heating cooker comprises: first controlling means 11 for controlling output of an inverter circuit 10; second control means 13 for controlling operation and display means 12; communication means 22 by means of which the first control means 11 and the second control means 13 communicate with each other; and monitoring means 18 by means of which the second control means 13 disables output from the first control means 11 to the inverter circuit 10 when communication with the first control means 11 is disrupted. In the case that the first control means 11 continues oscillation of the inverter circuit 10 due to some malfunction, output to the inverter circuit 10 is disabled; thereby, heating is surely stopped.

Description

  The present invention relates to a cooking device used in a general household, and in particular, in order to prevent the control means from having any trouble and continuing heating, the trouble is monitored by a plurality of control means, and if there is a trouble, an inverter The present invention relates to a cooking device that takes safety into account and disables output to a circuit.

  Conventionally, this type of cooking device has an error display and stops heating when the communication state of the control means becomes a communication error (see, for example, Patent Document 1).

  Hereinafter, a conventional cooking device will be described. FIG. 3 is a perspective view of a conventional induction heating cooker.

  In FIG. 3, a power switch 101 for turning on / off a commercial power source is a top plate 102 for placing an object to be heated. A heating coil 103 is disposed below the top plate 102.

  An inverter circuit for supplying a high frequency current to the heating coil 103, a control means for controlling the output of the inverter circuit, and an operation / display unit 104 including various switches and display elements are provided. Is set, the control means controls the output of the inverter circuit so as to obtain a preset heating output.

  The power switch itself does not turn on / off the commercial power supply, but includes a transformer circuit that converts the commercial power supply into a DC power supply and a control means configured by a microcomputer driven by the DC power supply. The control means detects that the power switch has been pressed by a HIGH or LOW signal from the ON / OFF switch (power switch) connected to, recognizes the ON / OFF state of the power switch, and supplies commercial power to each inverter circuit. Some control the drive of a switch (relay) that turns ON / OFF the supply of the.

  Also, the ON / OFF switch (power switch) outputs a HIGH signal when the power switch is pressed, a LOW signal when the power switch is not pressed, and a power supply when the power status is OFF. When the HIGH signal of the switch is input, the HIGH state is continuously output. When the HIGH state signal of the power switch is input when the power state is ON, the power supply state holding circuit that does not pass through the microcomputer changes the output to the LOW output. The output of the state holding circuit is input to the control means. When the power supply state holding circuit is HIGH output, the relay for supplying commercial power to each inverter circuit is turned ON. When the power supply state holding circuit is LOW output, each inverter circuit Some have control means for controlling to turn off a relay supplied with commercial power.

  In addition, since this type of cooking device is provided with a plurality of burners, some of them are provided with a plurality of heating coils 103 and inverter circuits. Each burner is provided with a control means (microcomputer), and each control means has a mode. Some have a control means (master function) for controlling.

For example, to what extent each burner can output the maximum output power of the device, for example, the control means with the master function by communicating the necessary information of each control means by either wireless or wired communication means In some cases, information is calculated by communication to the control means of each burner.

  The control means for each burner sends the current operation mode (such as heating mode and fried food mode) and the current output to the control means having a master function.

  Some control means having a master function display an error display when a communication signal from each burner cannot be obtained normally, and notify the user of a failure.

JP 2005-268208 A

  However, in the conventional configuration, when the control means for controlling the inverter circuit causes a problem that causes the inverter circuit to continue oscillating due to some problem, the communication error is recognized and the communication is stopped. Even in such a case, there was a problem that heating may be continued.

  The present invention solves the above-described conventional problems, and a cooking device that securely stops heating and ensures safety so that the oscillation of the inverter circuit is not continued due to some trouble in the control circuit. The purpose is to provide.

  In order to solve the above-mentioned conventional problems, a heating cooker according to the present invention includes a top plate disposed on an upper surface of a main body on which a cooking container is placed, and a heating coil disposed below the top plate and heating the cooking container. An inverter circuit for supplying a high frequency current to the heating coil, a first control means for controlling the output of the inverter circuit, an operating means for changing the output level of the inverter circuit, and a current output level A display means for displaying, a second control means for controlling the operation means and the display means, a communication means for the first control means and the second control means to communicate with each other, When the communication from the first control means is interrupted, the second control means invalidates the signal output from the first control means to the inverter circuit without going through the communication means. Those having a monitoring means that.

  As a result, when the first control means continues to oscillate the inverter circuit due to some trouble, the signal output from the first control means to the inverter circuit is invalidated without going through the communication means. Therefore, heating can be stopped reliably.

  In the cooking device of the present invention, there is a possibility that the control means has some trouble and the heating may be continued. If there is a trouble by monitoring the trouble by a plurality of control means, the output from the control means to the inverter circuit By disabling, it is possible to provide a cooking device that is safe.

The block diagram which shows the heating cooker in Embodiment 1 of this invention. The block diagram around the inverter circuit of the heating cooker in Embodiment 1 of this invention Perspective view of a conventional induction heating cooker

  1st invention arrange | positions the top plate arrange | positioned on the upper surface of a main body and mounts a cooking vessel, the heating coil which is arrange | positioned under the top plate and heats the cooking vessel, and the inverter which supplies a high frequency current to the heating coil A circuit, first control means for controlling the output of the inverter circuit, operating means for changing the output level of the inverter circuit, display means for displaying the current output level, the operating means and the display Second control means for controlling the means, and communication means for the first control means and the second control means to communicate with each other, wherein the second control means is the first control means. When communication from is interrupted, monitoring means for invalidating a signal output from the first control means to the inverter circuit without passing through the communication means is provided. As a result, when the first control means falls into a state where the inverter circuit continues to oscillate due to some trouble, the output from the first control means to the inverter circuit is invalidated to ensure heating. Therefore, it is possible to provide a cooking device in consideration of safety.

  In the second invention, in particular, the control means of the first invention transmits a predetermined communication code to the first control means, and the first control means responds to the communication code received from the second control means. When the communication code with the predetermined processing is returned to the second control means, and the second control means does not return the communication code with the predetermined processing from the first control means. And a monitoring means for invalidating the signal output from the first control means to the inverter circuit, so that the first control means keeps returning the same code to the second control means, and the inverter circuit When it falls into a state where it continues to oscillate, it can be reliably stopped by turning off the supply of commercial power to the inverter circuit, so a safe cooking cooker is provided Can That.

  In the third invention, in particular, the control means of the first or second invention is provided with a non-volatile storage means, and the storage means receives a signal output from the first control means to the inverter circuit by the monitoring means. A recording area for recording the number of times of invalidation is provided, and when the output to the inverter circuit is invalidated by the monitoring means, the number of times recorded in the recording area is incremented, and the power is turned off by the monitoring means It is possible to confirm later whether or not the problem is identified.

  In particular, the fourth invention includes notifying means for notifying the user by sound and voice when the output to the inverter circuit is invalidated by the monitoring means of any one of the first to third inventions. Thus, it is possible to inform the user that heating is stopped due to a problem.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 is a block diagram of a heating cooker according to the first embodiment of the present invention.

  Power supply ON / OFF means comprising a main body 1 constituting the outer shell and a top plate 3 disposed on the upper surface of the main body 1 for placing the cooking container 2 thereon, and comprising a relay for turning the commercial power supply 4 on / off from the commercial power supply 4 An AC / DC power supply 6 (switching power supply) is provided for stepping down the voltage to a necessary DC voltage via a rectifier circuit that converts the AC power supplied via 5a or the power ON / OFF means 5b to DC.

In the case of switching from power OFF to ON, first, the power ON / OFF means 5a is turned ON by the power switch 7, the switching power is driven, and a DC voltage is generated. Thereby, each control circuit can operate.

  The power supply state holding circuit 8 detects the power supply ON by a signal from the power supply switch 7, notifies the second control means 13 that the power supply is in the ON state, and holds the supply of the commercial power supply 4 to the AC / DC power supply 6. Therefore, the power ON / OFF means 5b is driven.

  Further, the power ON / OFF means 5c is driven in order to supply the commercial power source 4 to the inverter circuit 10. When the power is switched from ON to OFF, when the power switch 7 is turned on by the user when the power is turned on, the power supply state holding circuit 8 detects the power supply OFF and notifies the second control means 13 that the power supply is turned off. In addition, in order to turn off the supply of the commercial power supply 4 to the AC / DC power supply 6, the power ON / OFF means 5b is turned off.

  Further, the power ON / OFF means 5c is turned off in order to turn off the supply from the commercial power supply 4 to the inverter circuit 10.

  A heating coil 9 for heating the cooking vessel 2 is provided below the top plate 3, and when the cooking vessel 2 is heated, the inverter circuit 10 applies high-frequency current to the heating coil 9 from the power source converted into direct current by the rectifier circuit. Supply.

  When a high-frequency current is supplied to the heating coil 9, an alternating magnetic field is generated, and an eddy current is generated on the bottom surface of the metal cooking vessel 2 disposed above the heating coil 9, and cooking is performed using Joule heat generated by the eddy current. The container 2 can be induction-heated.

  The first control means 11 controls the output of the inverter circuit 10 according to the heating power set by the user through the operation / display means 12. The first control means 11 of the present embodiment is constituted by a microcomputer.

  The second control means 13 and the first control means 11 installed in the operation / display means 12 include a communication means 22 that can communicate with each other, and the first control means 13 and the first control means 11 are arranged in accordance with the heating level transmitted from the second control means 13. The control means 11 controls the output of the inverter circuit 10.

  The second control means 13 of the present embodiment is constituted by a microcomputer. In this embodiment, the communication means 22 of each control means is wired serial communication. Note that the communication means 22 may use wireless communication.

  The first control unit 11 transmits the currently controlled heating output, temperature information of the top plate 3 and the like to the second control unit 13.

  The first control means 11 controls the output of the inverter circuit 10 in accordance with the temperature detected by the temperature detection means 14 configured by a thermistor disposed at the approximate center of the heating coil 9.

  In the present embodiment, the temperature detecting means 14 is composed of a thermistor, but a temperature detecting element such as a platinum sensor or an infrared sensor may be used.

  The first control means 11 and the second control means 13 include storage means 15a and 15b constituted by ROM or RAM on a microcomputer or EEPROM on a circuit. The storage means 15b stores control parameters of the inverter circuit 10 corresponding to each heating power setting, a sequence for automatic cooking, and the like.

  The second control means 13 has a function of turning off the heating by using the time measured by the time measuring means 16 to determine that the user has forgotten to turn off when there is no key operation of the operation unit 20 for a certain time after the start of heating.

  The notification means 17 stops the heating when the timer ends when the confirmation sound when the key of the operation unit 20 of the operation / display means 12 is pressed or when the timer function is used, and the timer is ended. Is notified.

  Further, the second control means 13 is a power LED (not shown) for notifying the user of the power supply state of the display unit 19 of the operation / display means 12 when the power is turned on by the output of the power supply state holding circuit 8. When the power is OFF, the power LED of the display unit 19 of the operation / display unit 12 is turned off.

  It is assumed that the second control means 13 stores the identification code unique to the first control means in the storage means 15a in advance. The second control means 13 transmits the count number changed for each unit mutual communication separately from the normal communication signal (information such as heating output, heating mode, power ON / OFF state, etc.) to the first control means. To do.

  The first control unit 11 returns a code obtained by adding the received count number and its own unique identification code to the second control unit 13.

  The monitoring unit 18 of the second control unit 13 subtracts the count number transmitted by itself from the returned code, and checks whether it is the unique identification code of the first control unit 11. The monitoring means 18 does nothing while the reply from the first control means 11 is normal, but the reply from the first control means 11 is abnormal, and the state is a predetermined number of times (5 in this embodiment). The first control means 11 is determined to be in an abnormal state.

  When the monitoring means 18 determines that the first control means 11 is in an abnormal state, the number of times that the output from the second control means 13 to the inverter circuit 10 is invalidated by the monitoring means secured in advance in the storage means 15a. The recording area number to be recorded is incremented by one.

  Further, the second control means 13 notifies the notification means 17 that the heating is stopped because of an abnormal state. In this embodiment, it is assumed that 0.3 seconds on and 0.3 seconds off are repeated 10 times by a buzzer. In this embodiment, the notification is made by the buzzer, but may be notified by voice.

  In the present embodiment, the monitoring unit 18 is described as a method for causing each control unit to calculate the identification code. However, the power may be turned off when communication is not returned.

  Further, the configuration is not limited to this as long as the first control unit 11 sends a reply based on a certain logic every time.

  FIG. 2 is a block diagram around the first control means 11 and the inverter circuit 10. When the monitoring means 18 determines that the first control means 11 is in an abnormal state, the second control means 13 turns on the inverter output invalidating means 23 (configured using a transistor in the present embodiment), and the first control means 11 is turned on. The PUSH / PULL output from the control means 11 is fixed to LOW.

  As a result, the HIGH / LOW signal output from the first control means 11 is fixed to LOW, so that the inverter circuit 10 cannot continue oscillation.

  As a result, in cases where there is a problem with the control means and there is a risk that heating will continue, if there is a problem, the output to the inverter circuit is disabled if there is a problem. It is possible to provide a heating cooker that takes into account.

  As described above, when the cooking device according to the present invention has a plurality of control means, the trouble is monitored by a plurality of control means, and if there is a trouble, the output to the inverter circuit is invalidated, Therefore, it is also effective for other uses such as a heating cooker.

DESCRIPTION OF SYMBOLS 3 Top plate 9 Heating coil 10 Inverter circuit 11 1st control means 13 2nd control means 5a, 5b, 5c Power supply ON / OFF means 6 AC / DC power supply 7 Power switch 8 Power supply state holding circuit 17 Notification means 18 Monitoring means 19 Display section (display means)
20 Operation part (operation means)
22 Communication means 23 Inverter output invalidation means

Claims (4)

A top plate disposed on the upper surface of the main body for placing the cooking container, a heating coil disposed below the top plate for heating the cooking container, an inverter circuit for supplying high-frequency current to the heating coil, and the inverter circuit First control means for controlling the output of the inverter, operating means for changing the output level of the inverter circuit, display means for displaying the current output level, second means for controlling the operating means and the display means. Control means, and communication means for the first control means and the second control means to communicate with each other, and the second control means stops communication from the first control means. A cooking device comprising monitoring means for invalidating a signal output from the first control means to the inverter circuit without passing through the communication means. The second control unit transmits a predetermined communication code to the first control unit, and the first control unit transmits a communication code obtained by adding predetermined processing to the communication code received from the second control unit. The second control means returns an inverter from the first control means when there is no reply from the first control means to which a predetermined processing code has been added. The cooking device according to claim 1, further comprising monitoring means for invalidating a signal output to the circuit. The second control means includes a nonvolatile storage means, and the storage means includes an area for recording the number of times the signal output from the first control means to the inverter circuit is invalidated by the monitoring means. The cooking device according to claim 1 or 2, wherein when the output to the inverter circuit is invalidated by means, the number of times recorded in the recording area is incremented. The cooking device according to any one of claims 1 to 3, further comprising notification means for notifying the user by sound and voice when the output to the inverter circuit is invalidated by the monitoring means.

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