JP3675423B2 - Cooking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cooking device such as a microwave oven, and more particularly to a control circuit that reduces power consumption during standby when not in use.
[0002]
[Prior art]
Recently, development of devices that are friendly to the global environment has been desired, and in particular for home appliances that are used on a daily basis, legislation concerning power consumption has been promoted. Among them, the standby power that is not in operation is said to be 10% to 20% of the total power consumption, and is attracting particular attention.
[0003]
Considering the actual usage of the microwave oven, the actual situation is that the non-operation time, that is, the standby time is overwhelmingly longer than the actual cooking time using high-frequency heating, a heater, or the like.
[0004]
A conventional microwave oven of this kind is generally as described in JP-A-7-217906. As shown in FIG. 5, the microwave oven includes a door switch 8 that operates in conjunction with opening and closing of a door interposed between a commercial power supply 7 and the power supply circuit 4 of the control circuit 3, and a door switch 8 in parallel. Connected and provided with a power switching means 5. The control circuit 3 is supplied with electric power via the door switch 8 when the door is opened, and the power switching means 5 is turned on and self-held based on a signal from the door switch circuit 10 that detects the opening of the door. Therefore, the power to the control circuit 3 is continuously supplied. When the door is closed and there is no input from the door switch circuit 10 or the key input circuit 2 within a predetermined time, the power opening / closing means 5 is turned off.
[0005]
In the above configuration, if the door is not opened / closed or key input is not performed within a predetermined time, the power opening / closing means 5 is turned off to cut off the power supply to the control circuit 3 of the microwave oven. Power was not supplied until the door was opened.
[0006]
There is also a microwave oven provided with a power switch instead of the door switch 8 connected in parallel with the power switching means 5. In this case, the power switch serves as a trigger for power supply to the power supply circuit, and power supply to the control circuit 3 is continued by turning on the power switching means 5.
[0007]
[Problems to be solved by the invention]
However, the above-described conventional microwave oven has the first problem that power is consumed for a certain period of time regardless of cooking each time the door is opened and closed. That is, in actual use, when cooking is finished and food is taken out, the door is always opened and closed, so that power is always consumed for a certain time each time the door is opened. In addition, there are many people who put food in a microwave oven for primary storage, and it is useless that a certain amount of power is consumed every time food is put in and out of the cabinet.
[0008]
Further, if the door is not closed, the conventional power is consumed, and there is a second problem that the door must be closed in order to turn off the standby power. In other words, the microwave oven is very hot after cooking, so there are many people who cool with the door open, and in some cases there are people who keep the door open, In this case, no power is saved.
[0009]
In addition, since the opening of the door or the power switch is used as a trigger for supplying power to the control circuit, the menu cannot be set unless the door is opened or the power switch is operated in the actual cooking setting operation. ing. In actual cooking setting operation, there are many people who set the menu before opening the door, and there is a third problem that the operation procedure is limited.
[0010]
[Means for Solving the Problems]
The power consumption during standby is mostly power consumption by a microcomputer (hereinafter referred to as “microcomputer”) and its peripheral circuits, and is how to eliminate this power consumption.
[0011]
In order to solve the above-mentioned problems, the present invention provides a heating means for heating food, a plurality of key input means for setting, a control means for controlling a cooking device, and a commercial power source that converts the commercial power source into a DC voltage. a power supply circuit for supplying power to the control means, and a power switching means for opening and closing the electric power to the control means provided between the power supply circuit and the control unit, and a holding means for controlling the oN / OFF operation of the power switching means The key input means has a function of outputting a signal for turning on the power opening / closing means to the holding means using the power supplied from the power supply circuit by a key operation, and a function of outputting a signal for setting the cooking state by the key operation. When the power switching means is OFF, the power switching means is turned on by a signal output from any of the key input means by a key operation or a signal from the control means. And, if the power-off means is operated after the ON without transition, in which so as to turn OFF the power switching means by a signal from the control means.
[0012]
According to the above-described invention, the power opening / closing means is turned on only after the cooking setting operation is performed regardless of whether the door is opened or closed, and power is supplied to the control means such as the microcomputer and the peripheral circuit. And the supply of electric power to the control means can be reduced irrespective of the closing.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The microwave oven according to claim 1 of the present invention includes a plurality of key input means for setting, a control means for controlling the cooking device, and a commercial power source connected to the commercial power source to convert the commercial power source into a DC voltage and supplying power to the control means. A power supply circuit to be supplied, a power switching means provided between the power supply circuit and the control means for opening and closing power to the control means, and a holding means for controlling the ON / OFF operation of the power switching means. , And a function for outputting a signal for turning on the power opening / closing means to the holding means using the power supplied from the power supply circuit by a key operation and a function for outputting a signal for setting the cooking state by the key operation Thus, when the power switching means is OFF, the power switching means is turned on by a signal output from any of the key input means by a key operation or a control means signal, and the power switching means is turned ON. If after the operation does not transition, because it so as to turn OFF the power switching means by a signal from the control means, it is possible to reduce power consumption in the control means regardless of the opening and closing of the door.
[0014]
A microwave oven according to a second aspect of the present invention includes a plurality of key input means for setting, a control means for controlling the cooking device, and a commercial power source connected to the commercial power source to convert the commercial power source into a DC voltage, A power supply circuit for supplying power, a power switching means provided between the power supply circuit and the control means for opening and closing power to the control means, and a holding means for controlling the ON / OFF operation of the power switching means. The key input means, after the power opening / closing means is turned on, uses the power supplied from the power supply circuit to turn on the holding means, so that the key input means performs a key operation so that the holding means receives a signal for turning on the power opening / closing means. When the power is input and the power switching means is turned on, power supply to the control means is started, a signal is input to the holding means via the supply circuit, the power switching means is continuously turned on, and power is supplied to the control means. But Then, after the supply of power to the control means is started, the control means is activated to enter the cooking setting standby state, so that the power consumption by the control means can be reduced regardless of whether the door is opened or closed. Can be reduced.
[0015]
The microwave oven according to claim 3 of the present invention is configured such that power is consumed only when the key input means is operated by a key, and in a standby state where food is not cooked, the power open / close means is in the open state. The power supply to the control means is cut off.
[0016]
The microwave oven according to claim 5 of the present invention determines that cooking is not performed and outputs a signal for turning off the power switching means to the holding means when no key input is made for a predetermined time after input from the key input means. Is. Therefore, unnecessary power consumption can be eliminated quickly.
[0017]
In the microwave oven according to claim 6 of the present invention, when the control means starts the program set by the key input, the key input must be made within a predetermined time after the program is completed or canceled. For example, a signal for turning off the power switching means is output to the holding means. Therefore, even if the door is opened and closed to take out food for a while after cooking is completed, the supply of power to the control means does not resume, so that unnecessary power consumption can be eliminated.
[0018]
The microwave oven according to a seventh aspect of the present invention outputs a signal for turning off the power switching means to the holding means when the control of the heating means by the control means becomes impossible. For this reason, since all power supply to the control means is cut off, the operation of the heating means can be surely stopped regardless of the control from the control means, so that a safer microwave oven can be obtained.
[0019]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[0020]
(Example 1)
FIG. 1 is a block diagram of a microwave oven control circuit according to the present invention, and FIG. 2 is a diagram showing a microwave oven control circuit according to a first embodiment of the present invention. In addition, the same code | symbol was attached | subjected to the structure similar to a prior art example.
[0021]
In FIG. 2, 7 is a commercial power source, 11 to 13 are a heater and a high-frequency generator that are heating means 1 for heating food, 2 is a key input means for inputting cooking settings, and a plurality of switches are configured in a matrix. It is. 3 is a control means for controlling the heaters 11 to 12 as the heating means 1 and the high-frequency generation source 13 in order to execute the cooking setting inputted by key operation, 4 is a power supply circuit of the control means 3, and 5 is a control means. Power opening / closing means for opening / closing power supply, 6 is a holding means for controlling the ON / OFF operation of the power opening / closing means 5, 9 is a door switch that is turned OFF / ON in conjunction with opening / closing of the door, and 14 to 16 are heaters 11. -12 and a relay contact for turning on and off the high-frequency source 13, 17 is a relay contact for cutting the heating means 1 in a standby state other than cooking operation and a standby state for cooking setting, and 18 is a relay contact 14-17. Is a relay drive circuit for turning ON / OFF, and 19 is a relay contact detection circuit for detecting ON / OFF of contact points 14 to 17 of the relay. The or welding of the relay contacts such as a circuit for detecting by monitoring the contact state of the relay. Reference numeral 20 denotes a microcomputer, which determines cooking conditions based on an input signal from the key input means 2 based on a preset program, and gives a signal to the relay drive circuit 18 so that the heaters 11 to 12 as the heating means 1 and high-frequency generation. The source 13 is controlled.
[0022]
Next, the operation and action will be described. In the standby state where the food is not cooked, the power switching means 5 is in the open state and the power supply to the control means 3 is cut off. The transistors Q1 to Q3 function to prevent the current from flowing into the control means 3 in the standby state. Similarly, the diodes D1 to D3 function to prevent a current from flowing into the control means 3 by key operation. Next, when any one of the plurality of keys SW1 to SW9 as the key input means 2 is operated, the resistors R4 to R6 and the resistors R7 to R9 are connected through the resistors to which the switches are connected. A signal for turning on the power switching means 5 is input to the holding means 6. When the power switching means 5 is turned on, power supply to the control means 3 is started, and a signal is input to the holding means 6 via the resistors R1 to R3 and the diodes D1 to D3 and R7 to R9, and the power switching means 5 is turned on. The power supply to the control means 3 is continued. After the supply of power to the control means 3 is started, the microcomputer 20 is activated to enter a cooking setting standby state. As for detection of key operations, after the microcomputer 20 is activated, scan signals are output in time series from the output ports P4 to P6 of the microcomputer 20. P1 to P3 are input / output ports, which are set as input ports in the cooking setting standby state and cooking state. When the key is not operated, a Hi level signal is input to P1 to P3. When the key is operated, the operated key is determined depending on the timing of the scan signal and which of the P1 to P3 the Lo level signal is input.
[0023]
Further, the microcomputer 20 starts subtraction of a preset timer time after activation, and when no input is made from the key input means 2 during that time, a signal for turning off the power switching means 5 when the remaining time becomes zero. By switching P1 to P3 to an output port and outputting a Lo level, a signal for turning off the power switching means 5 is output to the holding means 6.
[0024]
If a key input signal is input from the key input means 2 to the microcomputer 20 before the remaining time of the timer becomes zero, the timer time is reset and the subtraction of the timer time starts again, and the remaining time becomes zero. At this point, a signal for turning off the power switching means 5 is output to the holding means 6.
[0025]
When the cook starts cooking, the microcomputer 20 changes from the standby state for cooking settings to the cooking state. Then, the microcomputer 20 resets the timer time after the cooking program is completed or canceled, and the subtraction of the timer time starts again. If no input is made from the key input means 2 during that time, the remaining time becomes zero. A signal for turning off the power switching means 5 at the time is output to the holding means 6.
[0026]
Furthermore, after cooking is completed and cooking is canceled halfway, if it is not necessary to subtract a certain timer time for the purpose of cooling the microwave or displaying the status, the power switching means 5 is immediately turned off. Needless to say, you can. Needless to say, these timer times can be set to different minimum required times depending on the cooking program to be executed and the state of the microwave oven.
[0027]
When the key operation is performed after the power opening / closing means 5 is turned off, the power is again supplied to the control means 3.
[0028]
Further, when the microcomputer 20 is activated by a key operation from the standby state in which the power switching means 5 is opened, the microcomputer 20 detects the contact state of the relays 14 to 17 by a signal from the relay contact detection circuit 19, and the relays 14 to 17 When the contact should not be turned on, the power switching means 5 is turned off. Further, when the contacts of the relays 14 to 17 are not turned on during the cooking operation, the power switching means 5 is turned off. Further, when the contact of the relays 14 to 17 should not be turned on after the cooking operation is completed or canceled, the power switching means 5 is turned off.
[0029]
Even when the heating means 1 cannot be turned off due to a failure of the relay drive circuit 18, the microwave oven can be safely stopped by turning off the power switching means 5. Further, even when any one of the contacts of the relays 14 to 17 is welded, when the heating means 1 is cut into two at the relay contact 17 as in the present invention, the microwave oven can be safely turned off by turning off the power switching means 5. Can be stopped.
[0030]
(Example 2)
FIG. 3 is a diagram showing a microwave oven control circuit according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in that an input signal to the microcomputer 20 is input as analog data from the key input means 2 constituted by switches arranged in a matrix. The port P8 that detects 20 key inputs is an AD input port, and the number of ports that detect the key input of the microcomputer 20 is reduced. In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0031]
Next, the operation and action will be described. In the standby state where the food is not cooked, the power switching means 5 is in the open state and the power supply to the control means 3 is cut off. Next, when any one of the plurality of keys SW1 to SW9 as the key input means 2 is operated, each of the resistors R13 to R15 and the resistors R10 to R12 is connected to each of the resistors to which the switch is connected. A signal for turning on the power switching means 5 is input to the holding means 6. When the power switching means 5 is turned on, power supply to the control means 3 is started, and a signal for turning on the power switching means is input to the holding means 6 via the resistor R16, and the power switching means 5 is continuously turned on. The power supply to the means 3 is continued. Then, the microcomputer 20 is activated after the supply of power to the control means 3 is started. In the detection of the key operation in the microcomputer 20, the operated key is determined from the analog data input to P8 and the timing of the scan signal output in time series from P4 to P6. The analog data input to P8 is determined by the collector-emitter voltage Vce of any of Q1 to Q3 connected to the switch to be operated, the resistors R11 to R12, and the forward voltages Vf and R1 of D1. The input voltage Vin when SW1 to SW3 is pressed is Vin = Vcc (microcomputer power supply voltage) −R1 × ((Vcc−Vf−Vce) / R1) = Vf + Vce, and when SW4 to SW6 are operated Vin = Vcc (microcomputer power supply voltage) −R1 × ((Vcc−Vf−Vce) / (R1 + R12)), and when SW7 to SW9 are operated, Vin = Vcc (microcomputer power supply voltage) −R1 × ((Vcc-Vf-Vce) / (R1 + R11 + R12)). Then, the microcomputer 20 starts subtraction of a preset timer time after activation, and when no input is made from the key input means 2 during that time, when the remaining time becomes zero, Q4 is turned on from P7. A signal for turning off the power switching means 5 by outputting a signal is input to the holding means 6. And again, the microwave oven was put on standby.
[0032]
(Example 3)
FIG. 4 is a diagram showing a microwave oven control circuit according to the third embodiment of the present invention. Many use a rotary encoder as the key input means 2 of the microwave oven, and there are those having many input functions such as temperature setting, time setting and cooking menu selection as usage methods. The third embodiment is different from the first embodiment in that the key input unit 2 is used. In addition, the thing of the same code | symbol as Example 1 has the same structure, and abbreviate | omits description.
[0033]
Next, the operation and action will be described. The SW 10 is a rotary encoder, and by rotating, the switch configured inside operates from OFF → ON → OFF. In addition, the rotary encoder SW10 changes which of the two switches configured therein is turned on first depending on the rotation direction. Then, the microcomputer 20 determines the rotation direction and the number of times of ON by detecting whether the switch connected to the contact a or b of the rotary encoder SW10 is first turned on at the input port P1 or P2 of the microcomputer 20. ing.
[0034]
In the standby state where the food is not cooked, the power switching means 5 is in the open state, and the power supply to the control means 3 is cut off. The diodes D1 to D3 and the transistor Q4 function to prevent the current from flowing into the control means 3 in the standby state. Next, when either the rotary encoder SW10 or the key SW1 which is the key input means 2 is operated, the holding means 6 is supplied with power via the diodes D4 to D6 to which the operated rotary encoder SW10 or key SW1 is connected. A signal for turning on the opening / closing means 5 is input. When the power opening / closing means 5 is turned on, power supply to the control means 3 is started. When the supply of power to the control means 3 is started, the microcomputer 20 is activated, and a signal for turning on the power switching means 5 is output to the holding means 6 by outputting a signal for turning on the transistor Q4 from P7. . Then, the power switching means 5 is kept closed, and the power supply to the control means 3 is continued. Further, D4 to D6 indicate that the input signal input to the microcomputer 20 by the key operation wraps around the input port different from the input port to which the operated key is connected, and the key operated by the microcomputer 20 cannot be determined. It works to prevent. Further, the microcomputer 20 starts subtraction of a preset timer time after activation, and when no input is made from the key input means 2 during that time, when the remaining time becomes zero, Q4 is turned off from P7. A signal for turning off the power switching means 5 by outputting a signal is input to the holding means 6. And again, the microwave oven was put on standby.
[0035]
Hereinafter, an example of a comparison of standby electric energy between the microwave oven of the present embodiment and the conventional microwave oven will be described.
[0036]
In recent power supply circuits using switching elements, there are an increasing number of circuits having a function of reducing the power consumption by changing the switching condition in a standby state where the load of the power source is low in order to suppress the power consumption during standby. When the control means serving as the load of the power supply circuit is disconnected and the load is set to 0 as in this embodiment, there are many power supplies in which the power consumption of the power supply circuit is 50 mW or less. The standby power of the microwave oven of this embodiment using such a power supply circuit is 50 mW × 24 hours = 1.2 Wh per day. In the case of the conventional microwave oven, since the user's action to cook is judged by the opening / closing operation of the door, the power opening / closing means is turned on after the door is opened and closed for the time required for cooking setting and preparation. It is necessary to keep. In general, most of the time is about 10 minutes. The power consumed in such a case is consumed by the relay, microcomputer, display circuit, and peripheral circuits used in the power switching means, and is at least about 3 W. In the case of a household that uses a microwave oven six times a day, the power consumed per day after opening and closing the door to take out food is 3 W × 10 minutes / 60 minutes × 6 times = 3.0 Wh. Furthermore, the wasteful power consumption increases as the household uses the microwave oven more frequently. Further, when the microwave oven is used for temporary food storage, unnecessary power consumption (3 W × 10 minutes / 60 minutes × 2 times = 1.0 Wh) is consumed each time the food is stored and taken out. . Further, when the door is left open, the standby power does not become zero. Considering these actual use states, the microwave oven of the present embodiment based on the present invention has an effect of reducing standby power less than the conventional microwave oven.
[0037]
In the present embodiment, a microwave oven having a heater and a high-frequency generation source has been described as the heating means. However, the present invention is not limited to this, and the heating means may have only a high-frequency generation source. Of course, a cooking device that uses only a heater as the heating means may be used.
[0038]
【The invention's effect】
As described above, the microwave oven of the present invention detects the action that the user is going to cook by the key operation that is the setting operation of the cooking conditions, and power is supplied to the microcomputer that is the control means and its peripheral circuits, When cooking is not performed, power supply is turned off, so even if the door is opened and closed regardless of cooking, a certain amount of power is consumed each time the door is opened and closed. There is an effect that wasteful power consumption can be reduced.
[0039]
Moreover, since the opening of the door is not used as a trigger for supplying power to the control circuit, there is an effect that it is not necessary to open and close the door every time cooking is performed.
[0040]
Further, since there is no need to operate the power switch, there is an effect that the operation procedure is not limited.
[0041]
In addition, when the control of the heating means by the control means becomes impossible, the operation of the microwave oven is stopped by turning off the power opening / closing means, so that there is an effect that a safer microwave oven can be obtained. is there.
[Brief description of the drawings]
FIG. 1 is a block diagram of a microwave oven control circuit according to a first embodiment of the present invention. FIG. 2 is a microwave oven control circuit diagram according to a first embodiment of the present invention. FIG. 4 is a control circuit diagram of a microwave oven according to a third embodiment of the present invention. FIG. 5 is a control circuit diagram of a conventional microwave oven.
DESCRIPTION OF SYMBOLS 1 Heating means 2 Key input means 3 Control means 4 Power supply circuit 5 Power switching means 6 Holding means

Claims (7)

A heating means for heating the food, a plurality of key input means for setting, a control means for controlling the cooking device, and a power source connected to a commercial power source and converting the commercial power source into a DC voltage and supplying power to the control means A circuit, a power switching means provided between the power supply circuit and the control means for switching power to the control means, and a holding means for controlling the ON / OFF operation of the power switching means, the key input The means has both a function of outputting a signal for turning on the power switching means to the holding means using a power supplied from the power supply circuit by a key operation and a function of outputting a signal for setting a cooking state by a key operation. A cooking device characterized by the structure provided. A heating means for heating the food, a plurality of key input means for setting, a control means for controlling the cooking device, and a power source connected to a commercial power source and converting the commercial power source into a DC voltage and supplying power to the control means A circuit, a power switching means provided between the power supply circuit and the control means for switching power to the control means, and a holding means for controlling the ON / OFF operation of the power switching means, the key input And a means for turning on the holding means using the power supplied from the power supply circuit after the power switching means is turned on.   The cooking device according to claim 1 or 2, wherein the key input means is configured to consume power only when a key is operated.   The cooker according to any one of claims 1 to 3, wherein the plurality of key input means are configured in a matrix.   The control means outputs a signal for turning off the power switching means to the holding means when the key input is not made for a predetermined time after being inputted from the key input means by a key operation. The cooker according to item 1.   When the program set by the key input is started, the control means sends a signal for turning off the power switching means when the key input is not made within a predetermined time after the program is completed or canceled. It outputs to a holding means, The cooking device of any one of Claims 1-4 characterized by the above-mentioned.   The cooker according to any one of claims 1 to 4, wherein the control means outputs a signal for turning off the power switching means to the holding means when the control of the heating means becomes impossible.

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