JP2003090540A - Microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microwave oven which heats and cooks at a suitable cooking time corresponding to an amount of a material to be cooked and which prevents the material or the oven from being damaged by burning. SOLUTION: The microwave oven comprises a cooking time set key 14 for setting a desired cooking time T0 by a user, a controller 18 for controlling the drive of a magnetron 4, and a sensor 12 for detecting the temperature of a heating chamber 2. The controller 18 has a steam detecting means 25 for calculating a steam content based on input information from the sensor 12, detects a time T1 in which a steam content V detected based on a calculated value from the means 25, becomes a preset reference steam content V1, controls the drive of the magnetron 4 according to the time T1 when the time T1 is a preset time Ta or more, calculates a temperature gradient from a first reference temperature Vx preset based on input information from the sensor 12 to a second reference temperature Vy when the T1 is less than a preset time Ta, calculates a residual cooking time, and sets a new cooking time T3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave oven which heats and cooks food by high frequency.

[0002]

2. Description of the Related Art FIG. 8 is a control block diagram showing a conventional microwave oven, for example. In the figure, 51 is a heating chamber built in a main body (not shown), 52 is a magnetron that oscillates high frequencies, and the heating chamber 51 is irradiated with high frequencies from a power supply port 54 via a waveguide 53. 55 is the heating chamber 5
Reference numeral 1 denotes a motor disposed substantially at the center of the outer bottom portion of the heating element 1. Reference numeral 56 denotes a turntable disposed at the bottom portion of the heating chamber 51 that is connected to the motor 55 and rotates. The motor 55 is provided with a weight sensor 57 for detecting the weight of the food 58 placed on the turntable 56. Also, 5
Reference numeral 9 denotes a plate that accommodates the cooked food 58, and indicates tableware or the like arbitrarily selected by the user. Reference numeral 60 denotes a cooking time setting key for setting the time of heating and cooking arranged on an operation section (not shown) provided on the main body, 61 a start key for starting cooking, and 62 a weight detected by the weight sensor 57. It is an automatic cooking key that sets the cooking time based on and starts cooking.

Reference numeral 63 is a control device provided in the main body, which includes a control means 64, a heating control means 65 for controlling the drive of the magnetron 52, a timer 66 for counting a set cooking time, and an input of the weight sensor 57. The weight detection means 67 detects the weight of the cooked food 58 based on the information. The control means 64 uses the cooking time setting key 6
0, start key 61, automatic cooking key 62, timer 6
6. The operation of the heating control means 65 is controlled based on the input information from the weight sensor 57.

Next, the operation will be described. First, the manual cooking in which the user operates the cooking time setting key 60 to set the cooking time will be described. Dish 5 containing cooked food 58
9 is placed on the turntable 56 to prepare before heating and cooking. Next, the cooking time setting key 60 is operated to set the desired cooking time T0 to, for example, 200 seconds. Information on the set cooking time T0 is input to the control means 64 of the control device 63. Next, when the start key 61 is operated, the control means 64 operates the heating control means 65 based on the input information to drive the magnetron 52, and at the same time, the timer 66 counts the cooking time T0 (200 seconds) previously set. Instruct. By driving the magnetron 52, the high frequency is radiated from the power supply port 54 to the cooking object 58 in the heating chamber 51 through the waveguide 53.

The turntable 56 is rotated by the motor 55 at the same time when the start key 61 is operated.
When the cooked food 58 is heated and the timer 66 finishes counting the cooking time T0 (200 seconds), the control means 64 is started.
Stops the operation of the heating control means 65, and the magnetron 5
The driving of No. 2 is stopped, the motor 55 is stopped, and the cooking is ended.

Next, automatic cooking will be described. When the automatic cooking key 62 is operated after preparation before heating and cooking, the control means 64 drives the motor 55 to turn the turntable 56.
To rotate. At the same time, when weight information is input from the weight sensor 57, the weight detection means 67 sets the cooking time T0 (for example, 250 seconds) based on the input weight information. When the cooking time T0 is set, the timer 66 operates to start counting the cooking time T0, and at the same time, the heating control means 65 is operated to drive the magnetron 52. After that, the operation is the same as the manual cooking, and the description is omitted.

[0007]

Since the conventional microwave oven is configured as described above, the user first needs a cooking time (for example, 250 seconds) longer than the cooking time (for example, 200 seconds) suitable for the food to be cooked. If you set it, 50
In some cases, the food was overheated by being overheated for a second, the food was burned, and the microwave oven body was damaged. On the contrary, when the user sets the cooking time shorter than the cooking time suitable for the food, there is a problem that the heating becomes insufficient. Also, in the case of automatic cooking, the weight sensor measures the weight of the food and the cooking time corresponding to this weight is automatically set. However, the food placed on the turntable is a plate or the like. However, since the weight sensor detects the total weight of the dish and the dish, the weight of the dish is heavier than the dish to be actually cooked, and the cooking time becomes longer and overheating occurs. There was a point.

The present invention has been made to solve the above-mentioned problems, and can perform heating and cooking with an appropriate cooking time corresponding to the amount of food to be cooked, thereby preventing burnout of the food or microwave oven. It is intended to provide a microwave oven.

[0009]

In a microwave oven according to the present invention, a heating chamber for accommodating food to be cooked, a cooking time setting unit for setting a desired cooking time by a user, and a high frequency power is supplied to the heating chamber. A magnetron, a control means for controlling the drive of the magnetron, and a sensor for detecting the temperature in the heating chamber are provided, and the control means is provided with a vapor detection means for calculating the vapor amount based on the input information from the sensor. , Detecting the time until the amount of steam detected based on the calculated value from the steam detection means reaches a preset reference amount of steam, and when the detected time is equal to or longer than the preset time, The drive of the magnetron is controlled according to the cooking time set by the cooking time setting unit, and when the detected time is less than the preset time, based on the input information from the sensor. From the first reference temperature set in advance can calculate the temperature gradient until the second reference temperature to calculate the remaining cooking time, and sets a new cooking time.

When the newly set cooking time is longer than the cooking time set by the cooking time setting section, the control means newly sets the cooking time after the cooking time set by the cooking time setting section has elapsed. Until the set cooking time, the drive of the magnetron is controlled by weak heating.

Further, when the newly set cooking time is shorter than the cooking time set by the cooking time setting section, the control means causes the cooking time setting section to start after the newly set cooking time elapses. The driving of the magnetron is controlled by weak heating until the set cooking time.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1. Hereinafter, the first embodiment of the present invention will be described with reference to FIGS.
1 is a partially cutaway perspective view of a microwave oven according to the first embodiment, FIG. 2 is a control block diagram of the microwave oven according to the first embodiment, FIG. 3 is an operation flowchart diagram, and FIG. 4 is newly set. FIG. 5 is an operation time chart when the set cooking time is shorter than the cooking time set by the cooking time setting unit. FIG. 5 is a case where the newly set cooking time is longer than the cooking time set by the cooking time setting unit. FIG. 7 is an operation time chart diagram of FIG. In FIGS. 1 and 2, 1 is a main body of a microwave oven, 2 is a heating chamber having a front opening in the main body, 3 is a door for opening and closing the opening of the heating chamber 2, and 4 is a magnetron for oscillating high frequency. Therefore, the heating chamber 2 is irradiated with high frequency from the power supply port 6 through the waveguide 5. Reference numeral 7 is a motor disposed substantially in the center of the outer bottom of the heating chamber 2, 8 is a weight sensor integrally provided with the motor 7, 9 is a turntable which is connected to the motor 7 and rotates during heating and cooking, and 10 is a cooked food, It is housed in the plate 11 and placed on the turntable 9. The plate 11 indicates tableware or the like arbitrarily selected by the user. Reference numeral 12 denotes a sensor which is provided above the heating chamber 2 and includes a thermistor which detects the temperature inside the heating chamber 2 and the generation of steam.

Reference numeral 13 denotes an operation panel provided on the front surface of the main body 1 adjacent to the door 3, and a cooking time setting key 14 showing a cooking time setting section in which the user arbitrarily sets the time of heating and cooking.
And a start key 15 for starting cooking, and an automatic cooking key 16 for operating the weight sensor 8 to measure the weight of the food 10 and setting a cooking time corresponding to the measured weight to automatically start cooking. , A display 17 for displaying cooking time and the like.

Reference numeral 18 denotes a control device provided in the main body 1, which includes heating control means 19 for controlling driving of the magnetron 4, a timer 20 for counting time such as cooking time, a reference voltage V1 for detecting steam generation, and steam. The reference time Ta at which the heating occurs is stored, and a predetermined temperature (voltage V
x, voltage Vy) and the like, storage means 21, weight detection means 22 for detecting the weight of food 10 based on input information from weight sensor 8, and inside heating chamber 2 based on input information from sensor 12. Temperature detecting means 23 for detecting temperature
An amplifier circuit 24 that amplifies minute input information of the sensor 12, a steam detection unit 25 that detects the generation of steam based on the input information from the amplifier circuit 24, and a control unit 26.

The control means 26 includes a cooking time setting key 14,
Start key 15, automatic cooking key 16, weight detection means 2
2, temperature detecting means 23, vapor detecting means 25, timer 2
Based on 0 or input information from the storage means 21 or the like, the operation of the heating control means 19 is controlled and the display 17 displays the cooking time and the like.

The first embodiment configured as described above will be described with reference to FIGS. First, the dish 10 is placed in the dish 11, placed on the turntable 9 in the heating chamber 2, and the door 3 is closed to prepare for cooking. And
When the cooking time setting key 14 or the automatic cooking key 16 is operated, the input information is input to the control means 26. For manual cooking, the user sets the cooking time setting key 14
Is operated to set a desired cooking time T0. The control means 26 determines whether it is the cooking time T0 from the cooking time setting key 14 (S1), determines whether it is the input information from the automatic cooking key 16 if it is not the cooking time T0 (S2), and automatically cooks. If not, the process returns to S1.

After T0 is set by the cooking time setting key 14 in S1, the start key 15 is operated (S3),
The control means 26 drives the motor 7 to rotate the turntable 9. At the same time, the cooking object 10 also rotates and the heating control means 19 is operated to strongly heat the magnetron 4 (1
It is driven by energization (00%) (S4). Also, the timer 20
Driving time T set by the cooking time setting key 14
Start counting 0 (for example, 200 seconds) (S5),
The counted cooking time is displayed on the display unit 17.

As shown in FIG. 4, when the cooking object 10 in the heating chamber 2 is irradiated with the high frequency wave from the magnetron 4, the cooking object 10 is heated and steam is generated. When the sensor 12 detects the generation of this vapor and inputs it to the vapor detection means 25 via the amplification circuit 24, the vapor detection means 25 inputs the input information (measurement voltage V) to the control means 26. Control means 2
6 compares and judges the input measured voltage V and the reference voltage V1 stored in the storage means 21 (S6). If the determination result is V ≧ V1, the timer 20 measures the time T1 from the start of cooking (S7). If V ≧ V1 is not satisfied in S6, monitoring is performed until V ≧ V1.

Next, the control means 26 controls the measured time T1 and the time Ta (eg 1
20 seconds) (S8), and if T1 ≦ Ta, the temperature information (voltage V0) measured from the sensor 12 is detected by the temperature detection means 23 and stored in the storage means 21. Is compared with a predetermined temperature (voltage VX) (S
9). If V0 ≧ VX is not satisfied, monitoring is continued until V0 ≧ VX. If the comparison result is V0 ≧ VX, the time TX at that time is temporarily stored in the storage means 21 (S
10).

When the temperature in the heating chamber 2 further rises, the temperature information (voltage V0) measured by the sensor 12 is detected by the temperature detecting means 23 and input to the control means 26. The control means 26 stores the measured temperature information (voltage V0) in the storage means 2
The second predetermined temperature (voltage VY) stored in 1 is compared (S11). If the comparison result is V0 ≧ VY,
The time TY at that time is measured (S12). If V0 ≧ VY is not satisfied, monitoring is performed until V0 ≧ VY.

Next, the control means 26 calls the time TX temporarily stored in the storage means 21, and the time T from the time TY.
X is subtracted to calculate the time TZ required from VX to VY (S13). When the time TZ is calculated, the storage means 21
Clear the time TX that was temporarily stored in (S1
4).

Next, the control means 26 controls the time T calculated previously.
The remaining cooking time T2 after the lapse of time T1 from Z is calculated by the following formula (S15). T2 = 5TZ + 10 It should be noted that this formula is derived from experimental results. Then, for example, when TZ is 20 seconds, T2 is T2 = 5 × 20 + 10 = 110 seconds. From the time T2 calculated in S15 and the time T1 previously calculated, an appropriate cooking time T3 for the cooking object 10 is T3 = T1.
It is calculated from + T2 (S16). For example, T1 = 120,
If T2 = 110, T3 = 120 + 110 = 240 seconds.

When the cooking time T3 is calculated in S16, the control means 26 determines the proper cooking time T3 and the cooking time T0 (200 seconds) set by the cooking time setting key 14 at the start of cooking.
Is compared and determined (S17). For example, when the calculated cooking time T3 = 240 seconds and the cooking time T0 = 200 seconds input by the key operation, T3 ≧ T0.

If the determination result in S17 is T3 ≧ T0, the time T counted by the timer 20 from the start of cooking is compared with the cooking time T0 (S1).
8). For example, if T = 201 seconds and T0 = 200 seconds, T
≧ T0. As shown in FIG. 5, if T ≧ T0 in S18, the operation of the heating control means 19 is changed, and the driving of the magnetron 4 is switched to weak heating in which ON-OFF intermittent operation is performed (S19). Then, the operation is continued with weak heating until T ≧ T3 (S20), and if T ≧ T3, that is, the time T from the start of cooking becomes the proper cooking time T3, T0, T3 set in the timer 20 and The clock time T is reset and the cooking is finished (S21).

If it is determined in S17 that T3 ≧ T0 is not satisfied,
Subsequently, it is determined whether T ≧ T3 (S22). And T
If ≧ T3, as shown in FIG. 4, the heating control means 19
Operation of magnetron 4 is changed to ON-OFF
The mode is switched to the intermittent heating with weak heating (S23). Then, the operation is continued with weak heating until T ≧ T0 (S2
4). When the cooking time T reaches the set cooking time T0, S
Proceed to 21.

Further, in S8, T1≤Ta (for example, 120
If it is determined not to be (seconds), the time T from the start of cooking that has been timed is compared with the cooking time T0 set at the start of cooking (S25), and strong heating is continued until T ≧ T0, and then Proceed to S21.

When it is determined in S2 that the cooking is automatic, the weight detecting means 22 is operated based on the input information of the weight sensor 8.
Detects the weight of the food 10 (S26) and inputs the information to the control means 26. The control means 26 sets the cooking time T0 (S27), and then proceeds to S4.

As described above, in the first embodiment, the time T at the start of cooking when the steam reaches a predetermined level (voltage V1).
1 is set in advance for a predetermined time Ta (for example, 120
If it is longer than the second), it is determined that the amount of food is large, and it is determined that the set cooking time T0 is the proper cooking time, and heating control is performed. Further, when the time T1 is shorter than the predetermined time Ta, the time TZ required for the temperature rise (TX to TY) of the heating chamber 2
The cooking time T2 after T1 is calculated by T1 + T2
A more appropriate cooking time T3 is calculated. Then, the cooking time T0 set at the start of cooking is compared with the calculated cooking time T3. If T3 is smaller than T0, the weak heating is continued until the cooking time T3 is reached after the initially set cooking time T0 has elapsed. , The best cooking can be done.

Further, when the time T from the start of cooking exceeds the proper cooking time T3, the heating is made weak, and the weak heating is continued until the cooking time T0 elapses. You can

Embodiment 2. Second Embodiment of the Present Invention
Will be described with reference to FIGS. 6 and 7. Note that S31 to S37 and S40 to S48 in FIG. 6 are the same operations as S1 to S7 and S17 to S27 shown in FIG. In the second embodiment, the remaining cooking time T2 is calculated based on the time T1 when the steam becomes equal to or higher than the predetermined voltage V1. The formula at that time is
It is represented by T2 = 6T1-70. And the calculated T
An appropriate cooking time T3 = T1 + T2 is calculated from 2 and T1. The formula is derived from experimental results.

As described above, in the second embodiment, the time T1 from the start of cooking when the vapor detection means reaches the preset reference voltage (voltage V1) is detected, and this time T1 is detected.
Since the remaining cooking time T2 is calculated based on the above, and the optimum cooking time T3 is calculated, it is possible to perform optimum heating cooking without overheating or insufficient heating.

In the first and second embodiments described above, the drive control of the magnetron is turned on and off in order to operate with weak heating.
Although it is controlled, it may be controlled by an inverter or the like. Further, as the steam detecting means, a steam sensor capable of detecting the generation of steam may be used instead of the temperature sensor.

[0033]

As described above, according to the present invention, a new cooking time is set on the basis of the cooking time when the vapor detecting means detects the reference voltage and the time required for raising the predetermined temperature of the heating chamber. The cooking time set before the start is too long,
Optimal cooking is possible even if it is too short. In addition, since a new cooking time is set according to the cooking time when the vapor detection means detects the reference voltage, optimal cooking even if the cooking time set before starting cooking is too long or too short. You can

If the newly set cooking time is longer than the cooking time set by the cooking time setting section, the magnetron is set from the elapse of the cooking time set by the cooking time setting section to the newly set cooking time. Since the drive is controlled by weak heating, more optimal cooking can be performed.

When the newly set cooking time is shorter than the cooking time set by the cooking time setting unit, the magnetron is driven from the time when the newly set cooking time elapses until the cooking time set by the cooking time setting unit. Since it is controlled by weak heating, more optimal cooking can be performed.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of a microwave oven according to a first embodiment of the present invention.

FIG. 2 is a control block diagram of the microwave oven according to the first embodiment of the present invention.

FIG. 3 is an operation flowchart of the microwave oven according to the first embodiment of the present invention.

FIG. 4 is an operation time chart diagram of the microwave oven according to the first embodiment of the present invention.

FIG. 5 is an operation time chart diagram of the microwave oven according to the first embodiment of the present invention.

FIG. 6 is an operation flowchart of the microwave oven according to the second embodiment of the present invention.

FIG. 7 is an operation time chart diagram of the microwave oven according to the second embodiment of the present invention.

FIG. 8 is a control block diagram showing a conventional microwave oven.

[Explanation of symbols]

1 main body, 2 heating chambers, 3 doors, 4 magnetron,
5 waveguide, 6 power supply port, 7 motor, 8 weight sensor, 9 turntable, 10 cooked food, 11 dishes, 1
2 sensors, 13 operation panel, 14 cooking time setting key, 15 start key, 16 automatic cooking key, 17
Indicator, 18 control device, 19 heating control means, 20
Timer, 21 storage means, 22 weight detection means, 2
3 temperature detection means, 24 amplification circuit, 25 vapor detection means, 26 control means.

Continued front page    (72) Inventor Makizaki Hiroyuki             1728 Omaeda, Hanazono-cho, Osato-gun, Saitama 1728               Within Mitsubishi Electric Home Equipment Co., Ltd. F term (reference) 3K086 AA01 AA03 AA07 BA08 BB03                       CA03 CB04 CC02 CC20 CD10                       CD12 DA02 FA03                 3L086 AA01 CA04 CA16 CB05 CC10                       CC11 DA20 DA24 DA29

Claims (3)

[Claims] 1. A heating chamber for accommodating food to be cooked, a cooking time setting unit for setting a desired cooking time by a user, a magnetron for supplying a high frequency to the heating chamber, and a control means for controlling driving of the magnetron. And a sensor for detecting the temperature in the heating chamber, the control means is provided with a steam detecting means for calculating the amount of steam based on the input information from the sensor, based on the calculated value from the steam detecting means. The time until the detected amount of steam reaches the preset reference amount of steam is detected, and when the detected time is equal to or longer than the preset time, the cooking time set by the cooking time setting unit is used. When the drive time of the magnetron is controlled and the detected time is less than the preset time, the second reference temperature set in advance based on the input information from the sensor is set to the second reference temperature. A microwave oven, which calculates a temperature gradient until reaching a reference temperature, calculates remaining cooking time, and sets a new cooking time. 2. The control means, when the newly set cooking time is longer than the cooking time set by the cooking time setting unit, the control unit newly starts after the cooking time set by the cooking time setting unit has elapsed. The microwave oven according to claim 1, wherein driving of the magnetron is controlled by weak heating until a set cooking time. 3. When the newly set cooking time is shorter than the cooking time set by the cooking time setting unit, the control means causes the cooking time setting unit to start after the newly set cooking time elapses. The driving of the magnetron is controlled by weak heating until a set cooking time.
Or the microwave oven according to 2.