JP3710466B2 - rice cooker - Google Patents

Description

  The present invention relates to a rice cooker designed to reduce power consumption during operation standby.

  This type of rice cooker can operate at any time with respect to the drive circuit which operates the LED, the induction heating coil, and the sensor which operate | move at the time of a rice cooking, heat retention, and reservation execution, for example in the standby state which is not performing the operation of rice cooking or heat retention. So that power is supplied. In addition, in an induction heating rice cooker, electric power is also supplied to a drive circuit that operates an element cooling fan.

  In recent years, there has been an increasing demand for energy saving for each electric appliance. However, the rice cooker supplies power (standby power) to the drive circuit as described above in a standby state that is not used at all. Therefore, about 2 W of power is consumed per unit time.

  Then, this invention makes it a subject to provide the rice cooker which aims at reduction of the standby electric power in the state which is not using the rice cooker, and can aim at energy saving.

In order to solve the above problems, a rice cooker of the present invention includes an inner pot, load parts such as a heating means and a temperature sensor for heating the inner pot, a drive circuit for controlling each load part, the load parts and the drive. In the rice cooker provided with a power supply circuit for supplying power to the circuit, the heating means is an induction heating coil connected to an AC power supply via a rectifier circuit, and the rice cooker energizes the induction heating coil. An IGBT that is turned on and off, and an IGBT control circuit that controls on and off of the IGBT, both ends of the rectifier circuit and the induction heating coil are connected to the IGBT control circuit via switching elements, respectively. in being connected to the power supply circuit, a start switch for starting the power supply circuit, a power supply control circuit for maintaining or stopping the output state of the power from the power supply circuit, in a non-energized state When the start switch is operated and power is supplied from the power supply circuit, the power supply circuit becomes operable, and the power output from the power supply circuit is maintained via the power supply control circuit, while all load components are inactive. When it is determined that the output is in the middle, a control unit that stops output of power from the power supply circuit via the power supply control circuit is provided.

  Moreover, it is preferable that the said start switch is operation switches, such as rice cooking, heat retention, a reservation.

  In the rice cooker of the present invention, when the user operates the start switch, the power supply circuit outputs power, and the control unit maintains the output state via the power supply control circuit, while all the load components are in the non-operating state. Then, since the output of the power from the power supply circuit is stopped via the power supply control circuit, it is possible to reduce standby power consumed in a state where the user does not use it at all.

  The heating means is an induction heating coil connected to an AC power source through a rectifier circuit, and the rice cooker turns on and off the energization of the induction heating coil, and turns on and off the IGBT. It is an induction heating type rice cooker provided with an IGBT control circuit to be controlled, and since both ends of the rectifier circuit and the induction heating coil are connected to the IGBT control circuit via switching elements, respectively, the full load It is possible to reliably prevent the power consumption of the drive circuit of the induction heating coil that consumes a finer amount of power in the standby state in which the parts are not operating.

  Moreover, if the start switch is an operation switch for rice cooking, heat retention, reservation, etc., the power from the power supply circuit is not output, and the user directly outputs the power from the power supply circuit by performing the rice cooking operation. And since the output state can be maintained, operability can be improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a rice cooker 1 of the present invention. This rice cooker 1 is an induction heating system, which is roughly an inner pot 2, a main body 3, an induction heating coil 4 as a heating means, a temperature sensor 5 for the inner pot 2, a lid 6, a circuit board 20, and the circuit. It has a well-known configuration including a fan 8 for cooling an element mounted on the substrate 20.

  The lid body 6 is provided with a heat retaining lid heater 9 and a temperature sensor 10 for detecting the internal temperature of the inner pot 2, and a display panel 11 shown in FIG. The display panel 11 is provided with operation units 13a to 13g of a rice cooking switch, a heat retention switch, a cancel switch, a reservation switch, and various selection switches around the liquid crystal display unit 12 in the center. In the embodiment, an operation unit 14 of a start switch 29 described later is provided.

  As shown in FIG. 3, the circuit board 20 of the first embodiment includes a control unit including a DC power supply circuit 22, a load component drive circuit 28, a start switch 29, a power supply control circuit 30, and a microcomputer 34. I have.

  The DC power supply circuit 22 includes a diode 23 connected in series to the AC power supply 21 to rectify an AC current, an electrolytic capacitor 26 connected in series with the diode 23 to form a smooth DC high voltage, and a step-down chopper. A switching power supply circuit 25 that obtains a DC low voltage by stepping down by a known method such as a method, and an electrolytic capacitor 27 that stabilizes the DC low voltage are provided. Instead of the switching power supply circuit 25, a transformer type or a resistance step-down type may be used, or a power supply IC may be used.

  The drive circuit 28 is roughly divided into a drive circuit 28a such as an induction heating coil 4 and a lid heater 9 connected to the AC power supply 21, a fan 8 for element cooling connected to the DC power supply circuit 22, a temperature sensor 5, and the like. 10 and the like, and each of the load components is driven in accordance with an instruction from the microcomputer 34.

  The start switch 29 is connected to the switching power supply circuit 25 of the switching power supply circuit 25 at both ends, and starts the switching operation of the DC power supply circuit 22, and is a normally open switch that cuts off current supply when not in operation. Become. When a transformer type power supply circuit or a resistance step-down type power supply circuit is applied instead of the switching power supply circuit 25, the start switch 29 is provided in a connection line for supplying current to the transformer or the resistor, respectively.

  The power supply control circuit 30 maintains or stops the output state of power from the DC power supply circuit 22 and includes a transistor 31 that is a switching element. The transistor 31 has an emitter and a collector connected in parallel with the start switch 29, a base connected to the microcomputer 34 via a resistor 32, and is connected to the emitter side via a resistor 33.

  The microcomputer 34 controls the induction heating coil 4 and the lid heater 9 according to a stored program, and executes a predetermined rice cooking operation and a warming operation including reserved rice cooking, as in the conventional case. Further, in the present embodiment, when power is supplied from the DC power supply circuit 22 in a non-energized state and becomes operable, it is determined that the start switch 29 has been operated, and the DC power supply is connected via the power supply control circuit 30. While maintaining the power output state from the circuit 22, when it is determined that all the load components are not operating, the power output from the DC power supply circuit 22 is stopped via the power supply control circuit 30.

Next, power supply to each component by the rice cooker 1 will be described.
First, as shown in FIG. 4, when all the load components are not operating and the start switch 29 is not operated, the switching power supply circuit 25 of the DC power supply circuit 22 is in a state where the switching operation is stopped. No power is output from the DC power supply circuit 22 and the non-output state is maintained. The same applies when a transformer type power supply circuit or a resistance step-down type power supply circuit is applied instead of the switching power supply circuit 25.

  As shown in FIG. 5, when the start switch 29 is operated, the switching power supply circuit 25 of the DC power supply circuit 22 starts a switching operation. As a result, the DC power supply circuit 22 outputs power from the switching power supply circuit 25, whereby power is supplied to the microcomputer 34 as shown in FIG. In this state, the user can set the desired rice cooking operation.

  Next, as shown in FIG. 7, the microcomputer 34 energizes the base of the transistor 31 in the power supply control circuit 30 to increase the potential of the base of the transistor 31 and to turn on the transistor 31. As a result, as shown in the figure, the DC power supply circuit 22 outputs power by maintaining the transistor 31 in the power supply control circuit 30 through the microcomputer 34 even when the start switch 29 is turned off. Maintain state.

  When the predetermined rice cooking operation set by the user is completed, the rice cooker 1 shifts to a heat retaining operation. Then, when the user operates the cancel switch, the operation of all the load parts is stopped, and when the microcomputer 34 detects the non-operating state, the microcomputer 34 stops the output of the current to the power supply control circuit 30.

  Then, the transistor 31 of the power supply control circuit 30 is turned off. As a result, the switching power supply circuit 25 of the DC power supply circuit 22 is cut off, so that the switching operation is stopped to stop the output of power, and the power is not output as shown in FIG.

  Thus, in the rice cooker 1 equipped with the circuit board 20 of the first embodiment of the present invention, the DC power supply circuit 22 outputs power when the user operates the start switch 29, and the DC power supply circuit. No. 22 stops the output of power when all the load components are in the non-operating state, so that the standby power consumed in the non-use state can be reduced.

  FIG. 8 shows a circuit board 20 of the second embodiment mounted on the rice cooker 1. In order to prevent the power consumption of the drive circuit 40 of the induction heating coil 4 that consumes further fine power in the standby state in which all the load components are not operating in the first embodiment, the circuit board 20 A control circuit 44 is provided for bringing the drive circuit 40 into an electrically non-driven state.

Specifically, the drive circuit 40 of the induction heating coil 4 includes an IGBT control circuit 42, an IGBT 43a, an inverter circuit 43 having a capacitor 43b and a diode 43c on the downstream side of the rectifier circuit 41.
Here, in the conventional drive circuit, in the standby state, the power is supplied by the connection line L1 between the rectifier circuit 41 and the IGBT control circuit 42 and the connection lines L2 and L3 between the IGBT control circuit 42 and the induction heating coil 4. Was consumed.

  Therefore, in the present invention, a control circuit 44 including relays 45a, 45b, and 45c, which are switching elements, and a transistor 46 is provided. The contact terminals of the relays 45a, 45b, and 45c are provided on the lines L1, L2, and L3, respectively, and one of the coil terminals is connected to the DC power supply VDD, and the other is connected to the collector of the transistor 46. As with the transistor 31 of the first embodiment, the base of the transistor 46 is connected to the microcomputer 34 via the resistor 47, is grounded via the resistor 48, and the emitter is grounded. A switching element such as a photocoupler may be applied instead of the relays 45a, 45b, 45c.

  In the rice cooker 1 to which the circuit board 20 of the second embodiment is applied, as in the first embodiment, when all the load components are not operating and the start switch 29 is not operated, the DC power supply circuit 22 is Maintain the non-output state. When the activation switch 29 is operated, the microcomputer 34 is activated by the power output from the DC power supply circuit 22, and the microcomputer 34 detects the base of the transistor 31 in the power supply control circuit 30 and the transistor 46 in the control circuit 44. By supplying a current to the base, these transistors 31 and 46 are turned on.

  Thereby, the switching power supply circuit 25 maintains the power output state even when the start switch 29 is in the OFF state. In addition, the relays 45a, 45b, and 45c of the control circuit 44 maintain the ON state of the switch unit, and maintain the driveable state by energizing the drive circuit 40 of the induction heating coil 4.

  And when the rice cooker 1 complete | finishes predetermined | prescribed operation | movement and a user stops operation | movement of all the load components by operating a cancellation switch, the microcomputer 34 will go to the transistors 31 and 46 of the said power supply control circuit 30 and the control circuit 44 Stop the output of current. As a result, the DC power supply circuit 22 maintains the non-output state, and the IGBT control circuit 42 connected to the rectifier circuit 41 becomes in an electrically non-driveable state.

  FIG. 9 shows a circuit board 20 according to a third embodiment mounted on the rice cooker 1. This circuit board 20 applies the two-pole single-throw type switches 50a, 50b, and 50c to the rice cooking switch, the heat retaining switch, and the reservation switch without providing the dedicated start switch 29 shown in the first embodiment. When the operation units 13a, 13b, and 13c are operated, power is output from the DC power supply circuit 22 at the same time.

  In the rice cooker 1 to which the circuit board 20 of the third embodiment is applied, as in the first embodiment, the microcomputer 31 turns off the transistor 31 constituting the power supply control circuit 30 when all the load components are in the non-operating state. Therefore, standby power can be reduced. In addition, since the two-pole single-throw switch 50a, 50b, 50c is applied instead of providing the dedicated start switch 29, the user directly drives the microcomputer 34 by performing the rice cooking operation. Therefore, the operability can be improved.

  In addition, the rice cooker 1 of this invention is not limited to the said embodiment.

  For example, in the power supply control circuit 30 shown in the first to third embodiments, the transistor 31 is applied as the switching element, but a relay may be applied.

  Furthermore, in this embodiment, although it applied to the rice cooker of the induction heating system, it is applicable also to the rice cooker of the system which heats the inner pot 2 directly with an electric heater. Furthermore, in the above embodiment, the induction heating coil 4 and the lid heater 9 are provided as the heating means. The present invention can also be applied to a rice cooker provided with both heaters.

It is the schematic of the rice cooker of this invention. It is a top view which shows the display panel of a rice cooker. It is a circuit diagram which shows the circuit board of 1st Embodiment. It is a circuit diagram which shows the flow of the electric current of the circuit board of FIG. It is a circuit diagram which shows the flow of an electric current at the time of operating a starting switch from the state of FIG. FIG. 6 is a circuit diagram illustrating a current flow subsequent to FIG. 5. FIG. 7 is a circuit diagram showing a current flow subsequent to FIG. 6. It is a circuit diagram which shows the circuit board of 2nd Embodiment. It is a circuit diagram which shows the circuit board of 3rd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rice cooker, 2 ... Inner pan, 3 ... Main body, 4 ... Induction heating coil, 5 ... Temperature sensor, 6 ... Cover body, 7 ... Circuit board, 8 ... Fan, 9 ... Cover heater, 10 ... Temperature sensor, 20 DESCRIPTION OF SYMBOLS ... Circuit board, 21 ... AC power supply, 22 ... Power supply circuit (DC power supply circuit), 25 ... Switching power supply circuit, 28 ... Drive circuit, 29 ... Start switch, 30 ... Power supply control circuit, 31 ... Transistor, 34 ... Microcomputer (control) Part).

Claims (2)

Rice cooker comprising an inner pot, load parts such as heating means and temperature sensor for heating the inner pot, a drive circuit for controlling each load part, and a power supply circuit for supplying power to the load part and the drive circuit In
The heating means is an induction heating coil connected to an AC power source through a rectifier circuit, and the rice cooker controls an IGBT that turns on and off the energization of the induction heating coil, and an on and off of the IGBT. An IGBT control circuit, the rectifier circuit and both ends of the induction heating coil are connected to the IGBT control circuit via switching elements,
A start switch connected to the power supply circuit for starting the power supply circuit;
A power supply control circuit for maintaining or stopping the output state of power from the power supply circuit;
When the start switch is operated in a non-energized state and power is supplied from the power supply circuit, the power supply circuit becomes operable and maintains output of power from the power supply circuit via the power supply control circuit, while all loads A rice cooker comprising: a control unit that stops output of power from the power supply circuit via the power supply control circuit when it is determined that a component is not operating. The rice cooker according to claim 1, wherein the start switch is an operation switch for rice cooking, heat insulation, reservation, or the like.

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