JP3281790B2 - microwave - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a microwave oven,
In particular, it relates to heating control of a microwave oven.

[0002]

2. Description of the Related Art A conventional microwave oven has a weight sensor on a turntable on which an object to be heated is mounted, and detects the weight of the object to be heated and automatically sets an appropriate heating time. Have been. In this type of microwave oven, if the cook selects a cooking menu on the operation panel and operates the start key, the heating time and the heating temperature are appropriately determined according to the cooking menu and the automatically detected weight. It has become. Of course, there are cases where the cook wants to set the heating time and the heating temperature according to his / her preference, so that usually these parameters can be input manually.

[0003]

However, when inputting the heating time by the manual operation as described above, the cooker mistakenly sets an unnecessarily long time to cook the food by overheating or burning. Could fail. Furthermore, if heating is performed continuously at a high output for a long time, there is a possibility that the food may ignite.

The present invention has been made in order to solve such problems, and an object of the present invention is to provide a highly safe microwave oven which prevents abnormal heating even in cooking by manual operation. It is in.

[0005]

Means for Solving the Problems The invention made to solve the above-mentioned problems is directed to a microwave oven for heating an object to be heated housed in a cooking cabinet by using microwaves generated by a magnetron. Weight detecting means for detecting the weight of the object; b) calculating means for calculating the heating time based on the weight detected by the weight detecting means; c) operated by a cook to input a desired heating time. Operating means, d) notifying means for giving a warning to the cooker, and e) comparing the desired heating time inputted from the operating means with the heating time obtained from the calculating means, and And processing means for driving the notification means when the time is longer.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION In the microwave oven according to the present invention which has been made to solve the above problems, an appropriate heating time is calculated based on the weight of the object to be heated. Then, the heating time inputted by the cooker and the heating time obtained from the weight of the object to be heated are compared, and if the inputted heating time is shorter than the heating time obtained from the weight, the inputted heating time is inputted. The heating time is set as the actual heating time, and the magnetron is driven to perform the heating cooking. On the other hand, if the heating time obtained from the weight is longer, the processing means issues a warning by driving the notifying means to inform the cook himself that the time inputted by the cooker is not an appropriate value. I do. As this notifying means, means by visual means such as a lamp, or means by auditory means such as a buzzer or voice by voice synthesis can be used. When a warning is issued, the magnetron is not driven, and the cooker is in a standby state until it recognizes a malfunction of the input operation and inputs a proper heating time again.

[0007] The difference in the method of detecting the weight of the object to be heated by the weight detecting means makes it possible to immediately detect the weight when the object to be heated is placed on the turntable.
In some cases, the weight can be detected only when the turntable is rotated. Therefore, in the former case,
For example, a warning is issued when the cooking start key is operated, whereas in the latter case, after a series of heating operations such as rotating the turntable is started, the input heating time is input. If inappropriate, the cooking operation is interrupted and a warning is issued.

As described above, according to the microwave oven of the present invention, when the cooker mistakenly inputs a long cooking time that does not match the weight of the object to be heated and starts heating, , The heating operation is not performed, and a warning to the cook is performed instead. Therefore, in the case of manually inputting the heating time, it is possible to prevent burning and ignition due to abnormally heating the object to be heated, and it is also possible for the cooker to input a proper heating time again to obtain a desired heating time. Heating can be done.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the microwave oven according to the first invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing the configuration of the microwave oven, and FIG. 2 is an electrical configuration diagram of the microwave oven. In FIG. 1, a magnetron 3 is attached to an upper rear portion of a cooking cabinet 2 formed inside a housing 1, and microwaves are radiated into the cooking cabinet 2 via a waveguide 4. A turntable 5 on which the object to be heated 6 is placed is provided at a lower part in the cooking cabinet 2, and is rotated by a turntable motor 7. The turntable motor 7 is provided with a weight sensor 8 for detecting the weight of the object to be heated. An upper heater 9a and a lower heater 9b are provided on the outside of the top and bottom of the cooking cabinet 2, respectively.
Is provided, so-called oven heating is possible. A transformer 10 for oscillating the magnetron 3 is provided at a lower rear portion of the housing 1.

In FIG. 2, a fuse 12 for preventing overcurrent and a thermal fuse 13 for preventing heating are connected to a wiring from a power supply 11. Furthermore, it is connected to a circuit to be described later via a door switch 14 that conducts when the door of the cooking cabinet 2 is completely closed, and a first relay RL1. Door switch 14 and first relay R
When L1 is closed, the power supply 11 includes an illumination lamp 15 for illuminating the inside of the cooking cabinet 2, a blower motor 16 for blowing air for cooling the magnetron 3, and a turntable for which power is controlled by opening and closing the second relay RL2. Motor 7, third
The upper heater 9a, which is energized by opening and closing the relay RL3, the lower heater 9b, which is energized by opening and closing the fourth relay RL4, and the primary coil 10a, which is energized by opening and closing the fifth relay RL5. Each is connected in parallel. The secondary low-voltage coil 10b of the transformer 10 is a power supply for heating the heater of the magnetron 3,
The secondary side high voltage coil 10c is connected to a capacitor 17 for voltage doubler rectification and a diode 18, and the magnetron 3
It acts to apply a high voltage to the

The first to fifth relays RL1 to RL5 are controlled to be turned on / off by a control unit 19 composed of a microcomputer or the like. In addition, the control unit 19 sends signals according to the operation of the cooker such as selection of an automatic / manual setting course, selection of a cooking menu at the time of the automatic setting course, heating time and heating temperature input at the manual setting course from the operation unit 20. Is entered. In addition, detection signals are input from the weight sensor 8 and the temperature sensor 21 for detecting the temperature in the cooking cabinet 2 respectively. Further, the control unit 19 outputs a signal to the display unit 22 to perform a display according to the input from the operation unit 20 or a display for notifying the progress of the heating and cooking operation.

Hereinafter, the heating control operation when the manually set course is selected in the microwave oven having the above configuration will be described with reference to the flowchart of FIG. In the initial state, the first to fifth relays RL1 to RL5 are all in the off state. First, a key scan is performed from the control unit 19 to the operation unit 20 to determine whether there is a key input (step S1). If there is a key input, then it is determined whether or not the course selected by the key input is a manually set course (step S2). The process proceeds to a process other than the flowchart. If the course is the manually set course in step S2, subsequently, it is determined whether or not microwave heating by microwave heating by the oscillation of the magnetron 3 has been set (step S3). If it is not a range heating, it is an oven heating, so the process proceeds to a process other than this flowchart. If it is range heating in step S3, the process proceeds to step S4, where it is determined whether or not a timer operation for inputting a heating time has been performed. If no timer operation has been performed, the process returns to step S1 to determine whether to accept a key input. It is repeated.

When the timer is operated in step S4, the input value by the operation is set in the internal register of the control unit 19 as the heating time TM (step S5). Next, it is determined whether the heating start key has been operated (step S6). If the start key has not been operated, the process returns to step S4. If there is a start key input in step S6, the process proceeds to step S7, and first, a flag F0 indicating whether or not weight detection of the object to be heated has been executed is reset. Next, the first relay RL1 is turned on (step S8), whereby the illumination lamp 15 is turned on and the blower motor 16 is driven.

Next, the second relay RL2 is turned on, thereby energizing the turntable motor 7 to rotate the turntable 5 (step S9). Furthermore,
The fifth relay RL5 is turned on, and the primary coil 10a of the transformer 10 is energized (step S10). As a result, predetermined voltages are respectively generated in the secondary low voltage coil 10b and the secondary high voltage coil 10c of the transformer 10, and the magnetron 3 starts oscillating. In the case of range heating, heating by the heaters 9a and 9b is unnecessary, so that
The third and fourth relays RL3, RL4 are kept off.

After the oscillation of the magnetron 3 starts, the control unit 19
Starts counting down from the heating time TM set in the internal register (step S1).
1). Then, it is determined whether or not the heating time TM of the internal timer has become 0 (step S12). If not, the process proceeds to S13, and the flag F0 is set to 0.
Is determined. Immediately after the start of the oscillation of the magnetron 3, the flag F0 has been reset in the step S7, so that the process proceeds to the step S14. Here, the weight of the heated object 6 placed on the turntable 5 is detected by the weight sensor 8, and the heating time TO corresponding to the detected value is obtained (step S15). And the flag F
0 is set to "1" (step S16).

The manual setting mode is a so-called high output mode in which the magnetron 3 oscillates continuously. On the other hand, in the automatic setting course, either the high output mode or the low output mode in which the oscillation of the magnetron 3 is performed intermittently is selected according to the cooking menu. The heating time TO is determined in advance so that the heating time is about 20 to 50% longer than the longest heating time in the cooking menu in which the high output mode is selected in the automatic setting course. For example, assuming that the longest heating time is 5 minutes in the cooking menu in which the high output mode is selected in the automatic setting course, the heating time TO is determined to be about 6 to 7.5 minutes.

In step S17, it is determined whether or not the heating time TM of the internal register is longer than the heating time TO. If the heating time TM is longer, the process proceeds to step S18, and the internal timer replaces the countdown from the heating time TM. To start a countdown from the heating time TO. And
In the repetition of steps S18 and S19, the countdown is continued until the internal timer becomes 0, and then the process proceeds to step S20. Here, the oscillation of the magnetron 3 is stopped by turning off the fifth relay RL5, and the second relay RL2 is turned off to stop the operation of the turntable motor 7 (step S21). And
The first relay RL1 is turned off, and a series of heating operations ends (step S22).

If it is determined in step S17 that the heating time TO is equal to or longer than the heating time TM, the process returns to step S11 to continue counting down from the heating time TM and determine whether or not the internal timer has become 0 again (step S1).
2). If the internal timer has reached 0, the process proceeds to steps S20, S21, and S22, and the heating and cooking operation ends as described above. If the internal timer has not reached 0 in step S12, as described above, step S13
However, since the flag F0 has been set in step S16, the process returns from step S13 to S11 again.
As a result, the routine of steps S11 to S13 is repeated until the countdown of the internal timer reaches 0 from the heating time TM, and when it reaches 0, the heating cooking operation ends.

As a result of the above operation, if the heating time TM inputted by the cooker through the timer operation of the operation unit 20 is longer than the heating time TO obtained based on the weight of the food, the heating time TO is set as the actual heating time. The heating operation is performed.

Next, the heating control operation of one embodiment of the microwave oven according to the second invention will be described with reference to the flowchart of FIG. In addition, as a configuration, a notification unit including an alarm buzzer and an alarm lamp is additionally provided in the configuration of FIG. 2, and a drive signal is supplied from the control unit 19 to the notification unit at the time of abnormality notification.

In the microwave oven according to the second aspect of the present invention, when the heating time inputted by the cook is not appropriate, a processing operation for giving a warning to the cook is performed. For this reason, in the processing operation of step 17 already described, if the heating time TM is longer than the heating time TO, the process proceeds to step S30, and the notification unit issues a warning notification. That is, the alarm buzzer sounds and the alarm lamp is turned on to call the attention of the cook. Subsequently, the heating and cooking operation is interrupted by performing the processing of steps S20, S21 and S22. Of course, a warning may be issued after the heating operation is stopped. If the cook notices this warning and the heating time input again from the operation unit 20 is an appropriate value corresponding to the weight of the object to be heated, the heating cooking operation is continued to the end.

If the weight sensor 8 can accurately detect the weight of the object to be heated 6 without rotating the turntable 5, the heating control operation is performed as shown in FIG.
It may be modified as shown in the flowchart of FIG. That is, after the heating start key is operated in step S6, weight detection is executed (step S14), the heating time TO corresponding to this weight is obtained (step S15), and the heating time TM and the heating time TO are compared. (Step S17).
If the heating time TM is longer than the heating time TO, the process proceeds to step S30, a warning is issued, and the apparatus stands by in that state (that is, the state before starting the heating cooking). If the heating time TM is shorter than the heating time TO in step S17, the process proceeds to step S8 and the subsequent steps to execute a series of heating and cooking operations.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of an embodiment of a microwave oven according to the first invention.

FIG. 2 is an electrical configuration diagram of an embodiment of the microwave oven according to the first invention.

FIG. 3 is a control flowchart of a heating cooking operation in the embodiment of FIG. 2;

FIG. 4 is a control flowchart of a heating cooking operation in one embodiment of the microwave oven according to the second invention.

FIG. 5 is a control flowchart of a heating cooking operation in another embodiment of the microwave oven according to the second invention.

[Explanation of symbols]

 2 Cooking room 3 Magnetron 8 Weight sensor 19 Control unit 20 Operation unit

Continued on the front page (51) Int.Cl. ⁷ Identification code FI H05B 6/68 320 H05B 6/68 320N

Claims (1)

(57) [Claims] 1. A microwave oven for heating an object to be heated housed in a cooking cabinet by microwaves generated by a magnetron, comprising: a) weight detecting means for detecting the weight of the object to be heated; and b) said weight detecting means. Calculating means for calculating the heating time based on the weight detected in c), operating means operated by the cooker to input a desired heating time, d) notification means for warning the cooker E) comparing the desired heating time input from the operating means with the heating time obtained from the calculating means, and processing the notifying means when the desired heating time is longer; and A microwave oven comprising: