JP3376966B2 - High frequency heating device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency heating device using a microcomputer.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Unexamined Patent Publication No. 7-217906, a relay for power supply has been turned off after a fixed time has elapsed after closing a door or after heating.

[0003]

However, in such a conventional microwave oven, the relay for power supply is turned off after a certain period of time irrespective of the presence or absence of heating, so that heating is not required. Power was supplied only for the same time as when heating was performed, resulting in wasted power consumption.

[0004]

In order to solve the above problems, the present invention determines the time required for cooling the inverter power supply until it can output a high output, depending on the inverter output time, the size of the output, and the temperature in the heating chamber. After calculating and measuring the calculated time, the relay for power supply is turned off.

Thus, when the heating operation is not performed, the power supply can be turned off in a short time, so that wasteful power consumption can be suppressed.

When there is a heating operation, the power supply is turned on after measuring the time required for the inverter power supply to cool until it can output a high output, depending on the inverter output time, the size of the output, and the temperature inside the heating chamber. Can be turned off. Then, when the user heats the food again, the inverter power supply can output a high output, so that cooking can be performed in a short time.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is operated by a heating chamber for accommodating food, a door for opening and closing an opening for taking food in and out of the heating chamber, an inverter power supply, and the inverter power supply. In a high-frequency heating device comprising a high-frequency generator, control means, a power supply means for supplying power to the control means, an operation unit for setting cooking contents and inputting a heating start instruction, the control means comprises: The invar
After the power supply output is stopped , the inverter power supply is in a cooling state depending on the inverter output time, the output size, and the temperature in the heating chamber.
Can output a higher output than the maximum output that can be output regardless of
Calculates the time required to reach the cold state, and if the door is not opened within that time or there is no input from the operation unit, the power supply means is turned off after completion of counting of the calculated time. It is what makes me.

As a result, when the heating operation is not performed, the power supply can be turned off in a short time, and wasteful power consumption can be suppressed.

Further, when the user heats the food again, the inverter power source can output a high output, so that cooking can be performed in a short time.

According to a second aspect of the present invention, in addition to the first aspect of the invention, the inverter power source can be output regardless of the cooling state.
It will be in a cold state that can output higher than maximum output
To calculate the time required for
In order to secure sufficient time, the addition of a fixed time is included .

Thus, when cooking continuously, it is possible to prevent the power from being turned off before the continuous setting because the inverter cooling time is short after the cooking for a short time and the next cooking is performed. You can ensure enough time to set up.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a block diagram of a high frequency heating apparatus according to Embodiment 1 of the present invention.

In FIG. 1, reference numeral 1 denotes a main body of a high-frequency heating device, and a heating chamber 2 made of a ferromagnetic material is provided in the main body 1. The opening of the heating chamber 2 is provided with a door 3 that can be opened and closed to put food in and out of the heating chamber 2, and the operation unit 4 for setting menus, cooking time and the like is provided on the front surface of the main body 1. And a display unit 5 for displaying.

FIG. 2 shows a control circuit according to the first embodiment of the present invention. Reference numeral 6 denotes a commercial power source, which includes an interlock switch 7, an inverter power source 8 capable of producing a steady output and a high output for a predetermined time in a cold state, a relay contact 9a of a main circuit contact, and a power supply means. A relay contact 10a for connecting and disconnecting all loads and a fuse 11, which is an overcurrent protection device, are connected. The inverter power source 8 is connected to a high frequency generator 12 that operates by the inverter power source 8 and is a control unit 1 that is a control means.
3 is configured to control the output of the inverter power supply 8.

Further, the control unit 13 includes a step-down transformer 14 connected to a terminal on the side opposite to the power source 6 on the relay contact 10a side.
The control unit 13 includes a power supply circuit configured by a power supply stepped down by a step-down transformer 14, a microcomputer (hereinafter referred to as a microcomputer) and its peripheral circuits, and controls the entire microwave oven. An open monitor switch 15 which is turned off when the operation unit 4, the relay 10, the relay 9, and the door 3 are opened and is turned on when the door 3 is closed.
Are connected. The control unit 13 detects that the door 3 is closed when the open monitor switch 15 is on.

Further, the interlock switch 7 is of a bidirectional contact type, and its normally open contact terminal is the main circuit and is connected to the inverter power source 8. A relay contact 10a is provided in series between the power source 6 and the common terminal of the interlock switch 7. The normally closed terminal of the interlock switch 7 is connected to the power source 6 side of the relay contact 10a. The interlock switch 7 is interlocked with the opening / closing of the door 3 corresponding to the opening of the heating chamber, and is turned on (the normally open contact terminal is closed) when the door 3 is closed. , When the door 3 is open, it is turned off (the normally closed contact terminal is closed).

Next, the operation and action will be described with reference to FIGS. 3 and 4. FIG. 3 is a flowchart showing the control contents of the microcomputer. When the door 3 for opening and closing the heating chamber is opened, the commercial power supply 6 is supplied to the step-down transformer 14 via the normally closed contact terminal and the common terminal of the interlock switch 7, and the control unit 13 is activated (“start”). And the control unit 1
3 gives an operation signal to the relay 10 (processing step S
1). When an operation signal is applied to the relay 10, the relay contact 10a is turned on to form a power supply path to the step-down transformer 14. Therefore, after this, even if the user closes the door 3, the control unit 13 determines that the cooking setting state or the operating state, calculates the relay energization time by the method described below (processing step S2), and relays only the relay energization time. 10 is continuously operated (processing step S3), and the user can set and start cooking conditions during that time.

When the control unit 13 detects that the door 3 is closed (processing step S4), the cooking condition is set by the operation unit 4 and the start operation is performed (processing step S5), the control is performed. The unit 13 gives an operation signal to the relay 9 to control cooking (processing step S8). When an operation signal is given to the relay 9, its contact 9a is turned on and the inverter power supply 8 is energized. Then, the control unit 13 gives a control signal to the inverter power supply 8 so as to output an output according to the cooking conditions. The inverter power supply 8 inputs an output according to the control signal to the high frequency generator 12, and as a result, high frequency radio waves are supplied from the high frequency generator 12 to the heating chamber 2.

The output of this kind of inverter power supply 8 changes depending on the cooling state of the inverter power supply 8, and when it is cold, a high output higher than the maximum output that can be output in the normal state, that is, the maximum output that can be output regardless of the cooling state is output for a certain period of time. You can Therefore, in order to heat the food quickly, the control unit 13 gives a control signal to the inverter power source 8 so as to output a high output for a predetermined time immediately after the start, and outputs the output when the predetermined time is reached. A signal is applied to the inverter power supply 8 so as to drop the power.

Further, the control unit 13 determines the time from when the inverter power supply 8 stops outputting (processing step S9) to when the inverter power supply 8 is cooled and can output a high output again. And the temperature inside the heating chamber are corrected to calculate (processing step S1
0), the operation signal is continuously given to the relay 10 for the calculated time. In the meantime, the above-mentioned calculated time is counted by the microcomputer built in the control unit 13, and the control unit is operated after the user completes the counting without further key setting such as cooking conditions or operation of the door 3 (processing step S6). 13 stops the operation signal of the relay 10 (processing step S7), the relay contact 10a thereof is turned off, and the standby state is set.

FIG. 4 shows a flow chart of the relay energization time calculation unit. First, as a provisional value of the relay energization time, the energization time of the inverter power supply 8 is multiplied by the magnitude of the output, and further multiplied by the weighting constant m (processing step S11). The constant of this weighting m is the inverter power supply 8
It is an arbitrary value set in consideration of the time required for cooling. Next, the relay energization time is calculated by adding the value obtained by multiplying the temperature in the heating chamber by the weighting constant n and the previously calculated provisional value of the relay energization time.

When the user further sets cooking conditions or operates the door 3, the above-described calculation time is re-counted, and when the counting is completed, the control unit 1
3 stops the operation signal of the relay 10, and its relay contact 1
0a is turned off and enters a standby state.

Further, when the door 3 is opened and the control unit 13 is activated, the inverter power supply 8 is already in the cold state, so the control unit 13 controls the inverter power supply 8 to operate at a high temperature from the first cooking. It can be controlled to output.

Further, according to this embodiment, since the inverter power supply 8 is calculated from the measurement result of the temperature of the size and the heating chamber and output time as a cold time state inverter output time, the user briefly When cooking is performed, the output time is short and the temperature in the heating chamber is low, so that the cooling time of the inverter power supply 8 at this time is short. At this time, the power supply can be turned off in a short time, and unnecessary power consumption can be reduced.

Although only the relay has been mentioned as the power supply means, a semiconductor element such as a triac can be used.

(Embodiment 2) FIG. 5 is a flow chart showing a relay energization time calculation unit according to Embodiment 2 of the present invention. The configuration of the second embodiment is the same as that of the first embodiment, and only the control content of the microcomputer is different. That is, the flow chart showing the control content of the microcomputer is the same as the content of the first embodiment shown in FIG. 3, but in contrast to the flow chart of the relay energization time calculation unit of the first embodiment shown in FIG. As shown in the flow chart of the relay energization time calculation unit 5 in FIG. 5, a processing step 13 of “adding a certain time to the relay energization time” is added after the processing step S12.
Others are the same as in the first embodiment.

When the cooking is continuously continued, the inverter cooling time becomes short after the cooking for a short time.
After the cooking for a short time, the power was turned off before the setting was continued, but in the present embodiment, a processing step 13 of "adding a certain time to the relay energization time" is added,
Even after cooking for a short time, it is possible to secure enough time to set the next cooking.

As described above, the relay energization time after cooking for a short time can be ensured in addition to the time required for the inverter power supply 8 to be sufficiently cooled, and also for the time required for continuous cooking setting. it can.

[0030]

As described above, according to the high frequency heating apparatus of the first aspect of the present invention, the time during which the inverter power supply is in the cold state is determined by the inverter output time, the output magnitude, and the temperature in the heating chamber. After the calculation and counting the calculated time, the power supply can be turned off, so that if the user cooks for a short time, the power can be turned off in a short time thereafter. Therefore, power consumption can be reduced.

Further, when the door is opened and the control unit is activated, the inverter power supply is in a cold state, so that a higher output than the inverter power supply can always be output in the first cooking. Therefore, it is possible to provide an easy-to-use high-frequency heating device that can quickly heat a heated object.

According to the high frequency heating device of claim 2,
Even after cooking for a short period of time, the relay energization time can be ensured to be long enough for the inverter power supply 8 to be sufficiently cooled and to be set for continuous cooking.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a high-frequency heating device according to a first embodiment of the present invention.

FIG. 2 is a control circuit diagram of the high frequency heating device.

FIG. 3 is a flowchart showing the control contents of the microcomputer of the high-frequency heating device.

FIG. 4 is a flowchart showing a relay energization time calculation unit of the high-frequency heating device.

FIG. 5 is a flowchart showing a relay energization time calculation unit of the high frequency heating apparatus according to the second embodiment of the present invention.

[Explanation of symbols]

2 heating chambers 3 doors 4 operation part 6 power supply 8 Inverter power supply 10a Relay contact (power supply means) 12 High frequency generator 13 Control unit (control means)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H05B 6/64 H05B 6/64 F (58) Fields investigated (Int.Cl. ⁷ , DB name) H05B 6/64 H05B 6 / 68 F24C 7/02

Claims (2)

(57) [Claims] 1. A heating chamber for accommodating food, a door for opening and closing an opening for taking food in and out of the heating chamber, an inverter power supply, a high-frequency generator operated by the inverter power supply, a control means, and the control means. in the high frequency heating apparatus comprising a power supply means for supplying power to set the cooking contents, and an operation unit for inputting a heating start instruction to the control hand
After the output of the inverter power supply is stopped, the stage is higher than the maximum output that the inverter power supply can output regardless of the cooling state depending on the inverter output time, the output size, and the temperature in the heating chamber.
Calculate the time required to reach the cold state where the output can be output, and if the door does not open within that time or there is no input from the operation unit , count the calculated time
A high frequency heating device for turning off the power supply means after completion . 2. The inverter power supply is output regardless of the cooling state.
In a cold state where it can output a higher output than the maximum output
To calculate the time it takes to cook, set the settings to continue cooking.
Including a certain amount of time to ensure sufficient time to
Murrell high-frequency heating apparatus according to claim 1.