JPH0689888B2 - Heating cooker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a heating cooker for cooking by burning hot air heated by a burner, or a combination of an oven and a microwave oven for high-frequency electronic cooking. The present invention relates to a heating cooker including a compound cooker capable of both.

[Prior Art] Conventionally, as a heating cooker, as described in Japanese Patent Publication No. 58-51162, a heating chamber in a main body, a combustion chamber accommodating a burner, and combustion hot air heated here It is known to have a circulation fan for circulating the combustion hot air in the heating chamber and an air passage for guiding the air into the heating chamber. In this case, the combustion hot air heated by the burner in the combustion chamber is introduced into the heating chamber by the suction action of the circulation fan.

However, in this type of heating cooker, when the burner is stopped to adjust the temperature during cooking, cold air from the outside that is not heated in the combustion chamber is introduced into the heating chamber by the circulation fan through the air passage, and the heating air is heated. Since the cooling of the chamber is promoted, there is the inconvenience that the operating frequency of the burner increases.
Therefore, it is conceivable to connect the circulation fan to the operation of the burner and stop the operation of the circulation fan when the operation of the burner is stopped, but when the operation of the circulation fan during cooking is stopped,
There is a problem in that the temperature distribution in the heating chamber becomes non-uniform and heat unevenness occurs in the food.

On the other hand, in the cooking device, as described in, for example, Japanese Utility Model Publication No. 59-33937, a circulation fan is provided in the heating chamber, while the heating chamber is indirectly heated by the combustion hot air from the burner and the combustion hot air is heated in the heating chamber. It has been proposed to provide an exhaust fan that draws in an air passage on the outside of the air passage and discharges the air to the outside. In this case, the circulation fan is of the normal type that always operates during cooking, and the exhaust fan is of the interlocking type that operates in conjunction with the operation of the burner. According to this, the hot air in the heating chamber is constantly circulated during cooking by the circulation fan to achieve a uniform temperature distribution, and the exhaust fan is stopped when the burner is stopped, so that the heating chamber is kept as close as possible. Cooling can be prevented.

[Problems to be Solved by the Invention] However, the above-mentioned oven is an indirect heating type and has a structure in which the air heated by the burner is not introduced into the heating chamber but is discharged to the outside through an air passage outside the heating chamber. Therefore, it is inevitable that the temperature rise in the heating chamber is inferior to that of the direct heating type. Therefore, if this is combined with a microwave oven to form a compound cooker, when high-frequency heating and heating by combustion are used together, it is necessary to reduce the output of high-frequency heating in accordance with the rise of combustion heating. As a result, it takes longer to cook.

On the other hand, as shown in Japanese Utility Model Application Laid-Open No. 64-35310, in a direct heating type oven, a combustion fan is provided behind the burner in the combustion chamber. It has been proposed to forcibly send the hot air of combustion into the heating chamber. However, in this case, since the circulation fan is not provided and only the hot air is sent into the heating chamber, the temperature distribution in the heating chamber becomes uneven as in the conventional case, which causes uneven heating of the cooked food. There is a point.

In order to solve this, it is conceivable to provide the circulation fan as described above, but as the heating cooker, a direct heating method in which the combustion hot air from the burner is sent to the heating chamber by the combustion fan is desirable, in that case, An important issue is how to control the operation of two fans, a circulation fan and a combustion fan.

Therefore, an object of the present invention is to provide two fans in a heating cooker including a circulation fan that evenly distributes hot air in the heating chamber and a combustion fan that forcibly supplies the air heated by the burner to the heating chamber. It is to realize an excellent cooking function by appropriately adjusting and controlling the operation of.

[Means for Solving the Problems] A heating cooker according to the present invention includes a heating chamber for storing food, a combustion chamber for storing a burner, an air passage communicating between the heating chamber and the combustion chamber, and an inside of the heating chamber. A circulation fan that circulates air, a combustion fan that is driven in connection with the operation of the burner, and compulsorily sends the combustion hot air in the combustion chamber into the heating chamber through the air passage, and a circulating fan during cooking that is constantly operated. On the other hand, it is characterized by further comprising a control device for changing and controlling the operating states of the burner and the combustion fan before and after the temperature in the heating chamber reaches a predetermined value.

Further, in the present invention, as a control method of two fans by the control device, the burner is operated to continuously rotate the circulation fan and the combustion fan until the temperature in the heating chamber reaches a predetermined value, and the temperature in the heating chamber reaches a predetermined value. After reaching, the rotation of the circulation fan is continued, the burner is operated intermittently and the combustion fan is rotated intermittently, or the burner is operated and the circulation fan is rotated alternately forward and backward while heating. The combustion fan is continuously rotated at a predetermined speed until the temperature in the room reaches a predetermined value, and after the temperature in the heating room reaches a predetermined value, the burner is intermittently operated and the combustion fan is operated at the predetermined speed. A method of rotating at a lower rotation number is used.

Furthermore, according to the present invention, as a combined cooker that combines an oven and a microwave oven, a heating chamber that stores food,
A high frequency generator for generating a high frequency to be introduced into the heating chamber, a combustion chamber accommodating a burner, an air passage communicating between the heating chamber and the combustion chamber, a circulation fan for circulating air in the heating chamber, and a combustion chamber. The combustion fan forcibly sending the hot air of combustion into the heating chamber through the air passage and the circulating fan during cooking are constantly operated, while the burner before and after the temperature inside the heating chamber reaches a predetermined value. Also provided is a heating cooker characterized by including a control device for changing the operating state of the combustion fan to control the combustion fan, and rotating only the combustion fan in advance by the control device during high frequency heating.

[Operation] According to the present invention, the combustion hot air heated by the burner in the combustion chamber is supplied into the heating chamber through the air passage by the combustion fan. The hot air in the heating chamber is circulated by the circulation fan. At this time, the control device constantly operates the circulation fan, while changing the operating states of the burner and the combustion fan before and after the temperature in the heating chamber reaches a predetermined value and controls the burner and the combustion fan. As a result, when performing heating by combustion, or when using both heating by combustion and high-frequency heating, the temperature inside the heating chamber rises well and a uniform temperature distribution is achieved, and the temperature reaches a predetermined value. After that, by changing the operation of the combustion fan, rapid cooling of the heating chamber can be prevented and the temperature inside the heating chamber can be maintained at an appropriate value.

Further, by rotating only the combustion fan during high frequency heating, the heating chamber can be forcibly cooled and dehumidified, and the cooking control by the humidity sensor becomes possible.

[Example] FIG. 1 is a vertical cross-sectional view of a heating cooker of an example.

The cooking device 1 includes a heating chamber 4 for accommodating foods, a combustion chamber 6 formed below the heating chamber 4, and a combustion chamber 6 in the main body 2.
And an air passage 8 for guiding the combustion hot air generated in 1 to the inside of the heating chamber 4.

The heating chamber 4 has a heat-resistant inner surface and an air layer for heat insulation on the outer periphery. In the heating chamber 4, a tray 12 which can freely move in and out through an opening opened and closed by a door 10 on the front of the main body can be stored in two stages.

Above the rear side of the heating chamber 4, a magnetron 14 (Fig. 6) is provided as a high frequency generator for supplying high frequency radio waves into the heating chamber.
Is installed.

A turntable table 16a is installed at the bottom of the heating chamber 4,
A case 18 accommodating a motor 17 for rotating the turntable table 16a and a weight sensor is installed below the case 18. The weight sensor is of capacitance type, and is used for microwave oven cooking and defrosting with a microwave oven, which will be described later.
The weight of the food item is detected in order to check that the food item is placed on the turntable 16b or to set the cooking time according to the weight.

As shown in the figure, the dish 12 is housed in the heating chamber 4 regardless of the turntable 16b, but the presence of the dish 12 is confirmed by a sensor (not shown).

On the other hand, as shown in FIG. 2, the combustion chamber 6 is formed by a case 20 arranged below the heating chamber 4, a burner 22 is housed therein, and the combustion hot air heated by the burner 22 is forced. A combustion fan 24 that feeds into the air passage 8 and a motor 25 that rotationally drives this fan are installed.

An opening 19 (FIG. 1) is formed on the lower side of the case 18 that houses the turntable motor 17 and the weight sensor, and the combustion fan 24 operates in response to the operation of the gas burner 22 as described later. At this time, as shown by the arrow in FIG. 1, air is drawn from the lower side of the main body 2 through the opening 19 to cool the turntable motor 17 and the weight sensor.

The air passage 8 connecting the combustion chamber 6 and the heating chamber 4 is formed by the following members installed behind the heating chamber 4 as shown in FIGS. 3 to 5. That is, the combustion chamber side inlet passage 30 formed by the partition plates 26 and 28 extending in the lateral direction.
An intermediate passage 36 formed by a partition plate 32 arranged at the rear of the heating chamber 4 and a U-shaped partition plate 34 extending upward from the lower center of the partition plate 32, and the rear partition plate 32. It is composed of side edge portions 32L, 32R extending forward from both left and right sides and an outlet passage 38 formed by a cover 40 at the rear of the heating chamber.

Therefore, the combustion hot air heated by the burner 22 of the combustion chamber 6 is
By the operation of the combustion fan 24, as shown by the arrows in FIG. 3 and FIG. 4, it enters from the inlet passage 30 and is divided into the left and right intermediate passages 36, and then a large number of through holes 42 provided in the rear partition plate 32 are formed. It is introduced to the inside of the heating chamber 4 through the outlet passage 38 that passes through the rear passage plate and goes to the front from the left and right of the rear partition plate 32.

At this time, the operation of the combustion fan 24 cools the turntable motor and the weight sensor as described above.

Next, a circular opening is formed in the center of the rear partition plate 32 of the heating chamber 4.
44 is provided, and a circulation fan 46 is rotatably arranged behind it. As shown by the arrow in FIG. 5, the circulation fan 46 sucks the air in the heating chamber 4 rearward from the opening 44 of the partition plate 32 and, together with the hot air burned by the burner 22, both left and right sides of the partition plate 32. The hot air in the heating chamber 4 is circulated by sending the hot air into the heating chamber 4 again from the outlet passage 38, and has a function of rapidly increasing the temperature in the heating chamber 4 and eliminating uneven heating during operation. . In other words, in this embodiment, the combustion fan 24 allows the air passage 8
By mixing the combustion hot air fed into the heating chamber 4 with the circulating hot air in the heating chamber 4 and supplying the mixed hot air into the heating chamber 4, the temperature inside the heating chamber is made uniform.

The rotation shaft 48 of the circulation fan 46 is connected to the shaft of a motor 52 housed in a motor case 50 attached to the rear of the back of the cover 40, and is driven by the rotation thereof.

As shown in FIG. 1, a cooling passage 54 is formed between the cover 40 at the rear of the heating chamber and the motor case 50 and communicates with the outside through the case 50 having an open rear portion. The cooling passage 54 has an upper end. Is an exhaust passage 55 at the upper rear of the main body 2 and the main body 2
It communicates with an exhaust pipe 56 extending upward from the. A humidity sensor 58 is installed above the cooling passage 54, and a fan 60 coaxial with the circulation fan 46 is provided in the cooling passage 54 in order to cool the periphery of the humidity sensor 58 to a temperature not higher than the heat resistant temperature of the sensor. It is provided.

As shown in FIG. 1, a punching plate 62 that allows air to pass through in the rear side of the heating chamber 4 and in front of the partition plate 32, but blocks high frequency waves in the heating chamber 4 from leaking to the outside.
Is installed.

Further, as shown in FIG. 6 and FIG. 7, the magnetron 14 is attached to the upper right end of the rear surface of the cooker main body 2, and below the electronic circuit board 64 on which the circuit described later is mounted. A fan 66 for cooling the magnetron is installed, and air is blown by the fan 66 to the magnetron 14 on the outside of the fan 66, and in order to prevent contact with the electronic circuit board 64 to which a high voltage is applied, it also serves as an air guide made of synthetic resin. A board protection member 68 is attached.

Further, as shown in FIG. 6, a handle 10a of the door 10 of the main body 2
A case 70 accommodating a fan for cooling is provided on the upper side surface of the main body, and the inside of the case is configured to communicate with the exhaust pipe 56 shown in FIG. This fan is
A temperature sensor 57 installed in the exhaust passage 55 shown in FIG.
It should be operated only when the temperature inside the heating chamber detected by (for example, a thermistor) is equal to or higher than a predetermined temperature (for example, 100 ° C.). However, in the case of a microwave oven operation described later, it is not operated.

Next, FIG. 8 shows the combustion fan 24 and the circulation fan 46 of the embodiment.
3 is a circuit diagram including a control device that controls the operation of the burner 22. FIG.

This control device is mainly composed of a CPU 82 to which a predetermined drive voltage is supplied from a power supply circuit 80 connected to a commercial power supply (100 V AC). The CPU 82 includes a key operation section 83 arranged on the front surface of the main body for selecting various cooking operations, the weight sensor 84, the heating room temperature sensor 57, and the humidity sensor 5 described above.
8, a door switch 86 for detecting the opening of the door 10, a detector such as a photo coupler 88 for detecting the rotation of the combustion fan 24, and the turntable 16, the combustion fan 24, the circulation fan 46, the magnetron cooling fan 66 described above. Motors 25, 52, 67 which are the driving sources for the magnets and the magnetron which is a high frequency source
A drive circuit 90 including an inverter for driving 14 is connected to a display unit 91 arranged on the front surface of the main body and including a temperature display unit and the like used in a cooking operation described later.

The drive circuit 90 including an inverter makes the heating speed of the magnetron 14 variable according to the type of cooking when the heating speed of the food cooked by the magnetron 14 is faster than the heating speed of the burner 22.

Further, the CPU 82 has two solenoid valves 92, 94 connected in series for supplying gas to the burner 22 as described later, and
The drive solenoids MV1, MV2, MV3 of the solenoid valve 96, which are in parallel with the bypass passage 96a for switching the amount of gas, are connected in series with the solenoid valves 92, 94, and the park electrode (sparker) 97 for igniting the burner 22. A signal generation circuit 98 that drives the flame sensor 99 that detects combustion of the burner 22 is connected.

A predetermined voltage is supplied from the power supply circuit 80 to the motor and drive circuit 90 through the switch 100.

The CPU 82 is configured to output a signal for controlling the operation of the motor, magnetron or the like according to the detection signals from the various detectors as described above.

The combustion fan 24 and the circulation fan 46 of the embodiment are controlled by the control device as shown in FIG. That is, the ninth
The figure shows the circulation fan 46, the combustion fan 24 and the burner of the embodiment.
FIG. 4 is a waveform diagram showing control signals for a circulation fan motor (FM) 52, a combustion fan motor (NFM) 25, and solenoid valves 92, 94, 96 that operate 22 respectively, and are controlled by (A) and (B) in the figure. Aspects are different.

In (A), the circulation fan 46 and the combustion fan 24 are continuously rotated at predetermined rotation speeds (for example, 1500 rpm and 2500 rpm) until the temperature inside the heating chamber 4 reaches a predetermined value. After reaching the predetermined value, the circulation fan 46 continues to rotate and the combustion fan 24 rotates intermittently. At this time, the combustion fan 24 is synchronized with the input to the gas burner 22. That is, the input to the burner 22 is also a predetermined amount of heat (for example, until the temperature in the heating chamber 4 reaches a predetermined value).
It is continuously supplied at 5300 kcal / m), but is intermittently supplied after the temperature in the heating chamber 4 reaches a predetermined value.

In this way, the circulation fan 46 always operates, while the burner
The operation of the combustion fan 24 corresponding to the operation of 22 is controlled by changing the operating state before the temperature in the heating chamber 4 reaches the predetermined value and after the temperature in the heating chamber 4 reaches the predetermined value. Good temperature distribution, a uniform temperature distribution can be achieved, and after the temperature reaches a predetermined value, rapid cooling of the heating chamber 4 can be prevented and the temperature in the heating chamber can be maintained at an appropriate temperature. Gas can be saved.

(B) shows the circulation fan 46 at a predetermined time interval (for example, 1
The temperature in the heating chamber 4 is continuously rotated at a predetermined rotation speed (for example, 2500 rpm) until the temperature in the heating chamber 4 reaches a predetermined value while rotating in a forward and reverse direction alternately (for each minute). After reaching a predetermined value, the combustion fan 24 is continuously rotated at a rotational speed lower than the predetermined rotational speed (for example, 2000 rpm). At this time, the input to the burner 22 is also continuously supplied with a predetermined amount of heat (for example, 5300 kcal / m) until the temperature inside the heating chamber 4 reaches a predetermined value, but the temperature inside the heating chamber 4 reaches a predetermined value. After reaching, the heat quantity is intermittently supplied with a heat quantity smaller than the predetermined heat quantity (for example, 3600 kcal / m).

In this case, the circulation fan 46 is rotated alternately in the forward and reverse directions to stir the air so that the temperature distribution in the heating chamber 4 becomes more uniform, while the combustion fan 24 is rotated even if the circulation fan 46 rotates in the reverse direction. By rotating continuously, hot air in the heating chamber 4 can be prevented from flowing back toward the combustion chamber 6.
In addition, after the temperature in the heating chamber 4 reaches a predetermined value, the input to the gas burner 22 is intermittently supplied with a heat amount smaller than the predetermined heat amount, so that the blowout temperature can be lowered and the uneven cooking of food can be eliminated. it can. According to this, the surface of meat such as roast chicken is not hardened, and an effect that it is finished softly can be obtained.

In addition to the above embodiment, it goes without saying that the operation control of the combustion fan 24 and the circulation fan 46 is changed depending on the type of cooking. The mode is as follows.

1. Continuous rotation of both combustion fan and circulation fan 2. Intermittent rotation of combustion fan / continuous rotation of circulation fan 3. Intermittent rotation of both combustion fan and circulation fan 4. Intermittent rotation of combustion fan / stop of circulation fan It may be controlled continuous rotation. Further, a mode in which the combustion of the burner and the rotation of the combustion fan are interlocked, and a mode in which the combustion of the burner is stopped and only the combustion fan is rotated are included.

Next, the operation of the embodiment will be described.

1. Microwave cooking As shown in FIG. 10 (A), first, when the operator operates a microwave key (not shown) of the key operation unit 83 to switch on, microwave cooking is selected. . afterwards,
The microwave cooking time is set in the timer by the time setting operation.

Next, when the operator turns on the cooking start key, the CPU 82 of the control device uses the signal from the weight sensor 84 to detect the turntable, that is, whether or not the food is placed on the turntable 16b (presence / absence). Check the “N
If it is "o", a signal is output to the display unit 91 on the front of the main body to display an error indicating that no food is placed. On the other hand, if a food is placed, the turntable motor 17 and The combustion fan motor 25 is driven, the magnetron 14 is energized, and the timer countdown is started.

After that, the above motor and magnetron are driven until the time set in the timer elapses, and when the set time elapses, the turntable motor 17 and the combustion fan motor
The drive of 25 and the power supply to magnetron 14 are stopped, and the completion buzzer sounds. This completes one operation.

In the above microwave cooking, the combustion fan 24 is driven for the following reason.

(A) Forced cooling of the heating chamber For example, at the time of thawing described later, it is necessary to lower the temperature of the heating chamber to an appropriate value prior to the thawing. In such a case, the burner 22 is not burned and only the combustion fan 24 is operated to send cool air into the heating chamber 4 to cool it. At that time, the circulation fan 46 may be operated together with the combustion fan 24.

The procedure for forced cooling in the case of thawing is as shown in FIG.

First, the operator decompresses a key on the key operation unit 83 (not shown).
When is turned on, the decompression operation is selected. Then, when the cooking start key is turned on, the CPU 82 performs the turntable check, and if "No", displays an error. On the other hand, if the food is placed, the temperature sensor
A signal from 57 is used to check whether or not the temperature in the heating chamber is below a predetermined temperature (for example, 60 ° C.), and if “Yes”, thawing and cooking is performed. On the other hand, when the temperature is higher than the predetermined temperature, the temperature display section on the front surface of the main body blinks and the caution buzzer sounds.

After that, when the operator opens the door of the main body, takes out or confirms the thawed food, closes the door again and presses the cooking start key, the CPU 82 operates only the combustion fan 24 to perform the forced cooling. To do. Then, the temperature inside the heating chamber 4 is checked, and when the temperature falls below a predetermined temperature, the temperature display section on the front surface of the main body is turned on, while the operation of the combustion fan 24 is stopped and the buzzer sounds. After that, when the cancel key is pressed, the state returns to the initial state.

By the way, it is also possible to carry out forced cooling without the food being put therein, and the procedure in that case is as shown in FIG.

First, when the operator turns on the temperature confirmation key (not shown) in the compartment (heating chamber) of the key operation unit 83, the CPU 82 causes the temperature in the heating chamber 4 to reach a predetermined temperature (for example, by a signal from the temperature sensor 57). If it is "Yes", the temperature display is turned on and the buzzer sounds.

On the other hand, when the temperature is higher than the predetermined temperature, the temperature display is blinked and only the combustion fan 24 is operated to perform the forced cooling. Then, the temperature inside the heating chamber 4 is checked, and when the temperature falls below a predetermined temperature, the temperature display section is turned on, while the operation of the combustion fan 46 is stopped and the buzzer sounds.

(B) Setting of initial state of humidity sensor When air is sent into the heating chamber 4 by operating only the combustion fan 24, pre-purge of vapor remaining in the heating chamber is performed. This removes the water remaining in the heating chamber,
The humidity sensor 58 can accurately detect humidity for new cooking. An example of the need to detect humidity in a microwave oven is when the completion time of cooking is determined by the amount of steam generated when warming cold cooked rice. Other examples of cooking using a humidity sensor will be described later.

(C) Vapor removal in a microwave oven As in the case of (b) above, when air is sent into the heating chamber 4 only by operating the combustion fan 24 without burning the burner 22, steam is discharged together with the air in the heating chamber. . This can prevent the door glass on the front of the main body from becoming fogged during cooking.

As shown in FIG. 10 (B), when the door 10 on the front of the main body is opened before the set time elapses during the microwave cooking, the driving of the motor and magnetron is stopped.
Then, when the door 10 is closed again and the cooking start key is turned on, the operation after the above turntable detection is started.

2. Oven Cooking As shown in FIG. 13 (A), when the operator first turns on the oven key (not shown) of the key operation unit 83, oven cooking is selected. After that, the operation time of the oven is set in the timer by the time and temperature setting operation, and the set temperature of the oven cooking is stored in the CPU 82.

Next, when the cooking start key is turned on, the CPU 82 starts driving the turntable motor 17, the circulation fan motor 52, and the combustion fan motor 25 and starts counting down the timer. In this case, the circulation fan 46 is assumed to be rotationally driven by the control method shown in FIG.

After that, the motor is driven until the time set in the timer elapses, and when the set time (for example, 8.5 seconds) elapses, the solenoid valves MV1, MV2, MV3 are energized to open the solenoid valve. Also activates the Sparker 97. Then, the flame sensor 99 installed in the combustion chamber 6 checks the flame of the burner 22 and when the flame is detected, the operation of the sparker 97 is stopped. After that, it is checked whether the temperature in the heating chamber has become higher than or equal to the set temperature. When the heating chamber is driven and the temperature of the heating chamber becomes lower than the set temperature again, the solenoids MV1 and MV2 are energized to open the solenoid valve and the sparker 97 is operated. By repeating the procedure after the flame detection check, the burner 22 and the combustion fan 24 are
The control is performed as shown in FIG.

On the other hand, by checking the flame of the burner 22,
If no flame is detected after 12 seconds), the solenoids MV1, MV2, MV3 are deenergized, the solenoid valve is closed, the operation of the sparker 97 is stopped, the turntable 16, circulation fan
The drive of 46 and the combustion fan 24 is stopped, and the buzzer sounds.

Also, when a predetermined time has elapsed, as shown in FIG. 13 (B), the solenoids MV1, MV2, MV3 are deenergized to close the solenoid valves, and the turntable 16b, the circulation fan 46 and the combustion fan 24 are driven. Stop and ring the buzzer.

Further, when the door 10 is opened during cooking, as shown in FIG. 13 (C), the solenoids MV1, MV2, and MV3 are deenergized to close the solenoid valve, and the turntable 16 and the circulation fan 46 are connected. Also, the driving of the combustion fan 24 and the countdown of the timer are stopped.

Thereafter, when the door 10 is closed again and the cooking start key is pressed, the operation is performed according to the procedure shown in FIG. 11 (A).

Normal oven cooking is as described above, but when yeast fermentation for bread cooking is performed, it is as follows.

As shown in FIG. 14, when the operator first turns on the oven key of the key operation unit 83, the oven cooking is selected, and the operation time is set to the timer by the subsequent time setting operation, and the key switch is further operated. The yeast fermentation is selected by the operation.

Next, the CPU 82 determines that the temperature inside the heating chamber 4 is a predetermined temperature (for example, 4
(0 ° C) or lower, and if "Yes", perform yeast fermentation control (Fig. 15) described later. On the other hand, when the temperature is higher than the predetermined temperature, the temperature display on the front of the main unit blinks and the caution buzzer sounds.

After that, when the operator opens the door of the main body to take out the food from the heating chamber, closes the door again, and presses the cooking start key, the CPU 82 operates only the combustion fan 24 to perform forced cooling. Then, the temperature inside the heating chamber 4 is checked, and when the temperature falls below a predetermined temperature, the temperature display section on the front surface of the main body is turned on, while the operation of the combustion fan 24 is stopped and the buzzer sounds. After that, when the cancel key is pressed, the state returns to the initial state.

The yeast fermentation control is performed as follows.

First, turntable motor 1 as shown in FIG.
7. The drive of the circulation fan motor 52 and the combustion fan motor 25 and the countdown of the timer are started.

After that, the motor is driven until the time set in the timer elapses, and when the set time (eg, 8.5 seconds) elapses, the solenoid valves MV1, MV2, and MV3 are energized to open the solenoid valve and activate the sparker 97. Let And the combustion chamber 6
The flame sensor 99 installed at the position checks the flame of the burner 22 and stops the operation of the sparker 97 when the flame is detected. After that, it is checked whether the temperature in the heating chamber 4 is higher than the yeast fermentation temperature, and when the temperature is higher than the yeast fermentation temperature, the solenoids MV1, MV2 and MV3 are deenergized to close the solenoid valve and rotate the combustion fan 24. When the temperature of the heating chamber becomes lower than the yeast fermentation temperature again by driving with a small number, the solenoids MV1 and MV2 are energized to open the solenoid valves and operate the sparker 97. By repeating the procedure after the flame detection check, the burner 22 and the combustion fan 24
Are controlled as described above.

On the other hand, by checking the flame of the burner 22,
If no flame is detected after 12 seconds), the solenoids MV1, MV2 and MV3 are deenergized to close the solenoid valve and stop the operation of the sparker 97, turntable 16, circulation fan.
The drive of 46 and the combustion fan 24 is stopped, and the buzzer sounds.

As described above, in the yeast fermentation control, since the circulation fan 46 is not operated, the temperature inside the heating chamber can be maintained at the set temperature for a long time even when the burner 22 is stopped.

3. Simultaneous operation of microwave oven and oven This operation is performed by the operator selecting simultaneous operation by key operation, as shown in FIG. in this case,
By the time and temperature setting operation, the operating time of the microwave oven and the oven is set in the timer, and the set temperature of the oven is stored in the CPU 82. Next, when the cooking start key is turned on, the above operations 1 and 2 proceed at the same time.

By the way, in the illustrated embodiment, the humidity sensor 58 is used for microwave oven cooking, but in gas oven cooking as well, there are cases where it is desired to detect boiling by detecting humidity, such as cooking rice. However, there is a problem that the humidity sensor cannot be used in the oven because the combustion heat contains moisture and gas.

In this embodiment, the following method for solving this problem is used.

First, as shown in FIG. 19 (A), only the combustion fan 24 is operated to dehumidify. Then, when microwave oven cooking is performed and the humidity sensor is operated to detect boiling, the humidity detection by the humidity sensor is stopped and oven cooking is started.

On the other hand, if you only cook in the oven,
As shown in FIG. 6B, combustion heating is intermittently performed, and the humidity is detected by the humidity sensor while the combustion heating is stopped. Then, when boiling is detected, the humidity detection is stopped.

4. Example of Cooking Using Humidity Sensor As shown in FIG. 17, when curry or stew is selected as a cooking menu, when the operator operates a predetermined key of the key operation unit 83, the CPU 82 causes the magnetron to operate. Operate 14 at maximum power. At this time, the combustion fan motor 25 is driven at a reduced rotational speed to remove steam from the heating chamber 4. Then, based on the detection signal from the humidity sensor 58, it is checked whether or not the humidity in the heating chamber 4 is equal to or higher than a predetermined humidity, and when the humidity is equal to or higher than the predetermined humidity, the elapsed time T1 from the start of cooking is stored.

Next, the ignition control and the strong combustion of the burner in the above-mentioned oven cooking operation are performed, and the magnetron 14 is operated with an output smaller than the maximum output.

At this time, the circulation fan motor 52 is alternately rotated forward and backward at a predetermined time interval, and the combustion fan motor 25 is rotated at a predetermined rotation speed until the temperature in the heating chamber 4 reaches the predetermined temperature, and reaches the predetermined temperature. After that, it is driven at a rotational speed lower than the rotational speed. The input to the burner 22 is also continuously supplied with a predetermined amount of heat until the temperature in the heating chamber 4 reaches a predetermined value.
After reaching the predetermined value, the heat is intermittently supplied with a heat amount smaller than the predetermined heat amount. After that, when the time T = kT1 (k is a predetermined number) obtained from the above T1 has elapsed, driving of the magnetron and oven cooking are stopped.

5. Example of Cooking Using Weight Sensor As shown in FIG. 18, when the operator selects a desired type of chawanmushi, the CPU 82 operates the magnetron 14
Is operated at the maximum output, and the weight G of the food is determined by the detection signal from the weight sensor 84 to a predetermined value (for example, 600 g).
It is checked whether or not it is the above, and in each of the cases of “Yes” and “No”, when the time T1 and T2 obtained according to the predetermined calculation formula have elapsed, the magnetron 14 is operated with an output smaller than the maximum output. In addition, the temperature in the heating chamber is controlled to a predetermined temperature by the above-mentioned oven cooking.

After that, it is checked again whether the weight G of the cooked food is equal to or more than a predetermined value, and in the cases of "Yes" and "No" respectively, when the time T3 and T4 obtained according to the predetermined calculation formula have elapsed. Turns on the magnetron 14 at an output smaller than the maximum output
The temperature is controlled to be off, and the temperature inside the heating chamber is controlled to a predetermined temperature by the above-mentioned oven cooking.

After that, when the time T5 obtained according to a predetermined calculation formula has elapsed, driving of the magnetron and gas oven cooking are stopped.

Although the embodiment has been described above, the present invention is not limited to this, and various modifications can be made.

[Advantages of the Invention] As described above, according to the present invention, heating including a circulation fan for circulating the hot air in the heating chamber and a combustion fan forcibly supplying the combustion hot air heated by the burner to the heating chamber In the cooker, the circulation fan always operates, and the combustion fan changes the operating state before the temperature in the heating chamber reaches a predetermined value and after it reaches the predetermined value. When used together, the temperature rise in the heating chamber is good and a uniform temperature distribution is achieved.
After the temperature reaches a predetermined value, rapid cooling of the heating chamber can be prevented and the temperature in the heating chamber can be maintained at an appropriate value, and fuel gas can be saved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a composite cooker of the embodiment, FIG. 2 is a perspective view showing constituent members installed on the bottom of the main body of the embodiment, and FIG. 3 is a perspective view showing the internal structure of the rear portion of the main body. FIG. 4 is a partial perspective view showing a part of the structure of FIG. 3, FIG. 5 is a horizontal sectional view showing the structure of the rear part of the heating chamber, and FIG. 6 is a perspective view seen from the rear of the cooker body. 6 is a partial perspective view showing a part of the rear part of the main body of FIG. 6, FIG. 8 is a circuit diagram including the control device of the embodiment, and FIG. 9 is a waveform diagram of signals for operating a circulation fan, a combustion fan and a burner, 10 to 18 are flowcharts showing the operation of the embodiment, and FIG. 19 is a diagram showing the relationship between humidity detection and oven cooking. 2 ... Cooker body, 4 ... Heating chamber, 6 ... Combustion chamber, 8 ... Air passage, 10 ... Door, 12 ... Plate, 14 ... Magnetron, 16 ... Turntable, 17 ... Motor , 18, 20 ... Case, 22 ... Burner, 24 ... Combustion fan, 30 ... Inlet passage, 36 ... Intermediate passage, 38 ... Exit passage, 40 ... Cover, 42 ... Through hole, 44 ... … Aperture, 46 …… Circulation fan, 52 …… Motor, 54 …… Cooling passage, 55 …… Exhaust passage, 56 …… Exhaust pipe, 57 …… Temperature sensor, 58 …… Humidity sensor, 60 …… Cooling fan, 80 …… power supply circuit, 82 …… CPU, 84 …… weight sensor, 86 …… door switch, 88 …… photo coupler, 90 …… drive circuit.

Front page continuation (72) Inventor Tadao Yamashita 2-26, Fukuzumi-cho, Nakagawa-ku, Nagoya, Aichi Prefecture Rinnai Co., Ltd. (56) Reference JP-A-1-269823 (JP, A) JP-A-62-77523 (JP, A) Actual opening Sho 58-16804 (JP, U) Actual opening Sho 53-160492 (JP, U) Actual opening Sho 64-35310 (JP, U)

Claims (4)

[Claims] 1. A heating chamber for storing food, a combustion chamber for storing a burner, an air passage communicating between the heating chamber and the combustion chamber, and a circulation fan for circulating air in the heating chamber.
A combustion fan driven in connection with the operation of the burner and forcibly sending the combustion hot air in the combustion chamber into the heating chamber through the air passage, and the circulation fan during the cooking are always operated, while the heating chamber is operated. And a control device for changing and controlling the operating states of the burner and the combustion fan before and after the temperature reaches a predetermined value. 2. The control device operates the burner to continuously rotate the circulation fan and the combustion fan until the temperature in the heating chamber reaches a predetermined value, and the temperature in the heating chamber reaches a predetermined value. After that, the circulation fan continues to rotate, the burner is intermittently operated, and the combustion fan is intermittently rotated. 3. The control device operates the burner and rotates the circulation fan alternately in forward and reverse directions, while continuously rotating the combustion fan at a predetermined rotation speed until the temperature in the heating chamber reaches a predetermined value. The rotation is performed, and after the temperature in the heating chamber reaches a predetermined value, the burner is intermittently operated and the combustion fan is rotated at a rotation speed lower than the predetermined rotation speed. ) The cooker described above. 4. A heating chamber for containing food, a high frequency generator for generating a high frequency to be introduced into the heating chamber, a combustion chamber for storing a burner, and an air passage for connecting the heating chamber with the combustion chamber. A circulation fan that circulates air in the heating chamber, a combustion fan that forcibly sends combustion hot air in the combustion chamber into the heating chamber through the air passage, and a circulation fan that constantly operates during cooking, And a controller for changing the operating states of the burner and the combustion fan before and after the temperature in the heating chamber reaches a predetermined value, and the controller controls only the combustion fan in advance during high frequency heating. A heating cooker characterized by rotating.