JP3102644B2 - Cooking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a cooking device for heating food in a cooking chamber by radiant heat of a heater.

(Prior Art) Conventionally, as a heating cooker of this type, for example, a heater is provided on an upper surface of a cooking chamber, and food stored under the heater is heated and baked by radiant heat of the heater. was there.

(Problems to be Solved by the Invention) By the way, after the start of cooking, gas such as steam is gradually generated from the food with the rise of the temperature in the cooking chamber.
When the temperature rises to about 100 ° C., the space inside the cooking chamber is filled with gas such as steam generated from food. In this state, since a part of the radiant heat from the heater is absorbed by a gas such as steam, the heating efficiency decreases,
There is a disadvantage that it takes a long time to cook, or the food is in a steamed state, and the baked state is deteriorated.

Therefore, in order to solve such a drawback, a ventilation fan that ventilates the cooking chamber is provided, and the ventilation fan exhausts gas such as steam generated from food to the outside during the heating cooking. It is considered.

However, if ventilation of the cooking chamber is continued from the beginning of the heating cooking, even the hot air in the cooking chamber continues to be discharged, so that the heating efficiency is reduced, and in particular, the temperature rise after the start of the cooking becomes significantly slow. After all, it takes a long time to cook. Moreover, the inside of the cooking chamber is dried too much by the ventilation action, so that moisture is deprived from the surface of the food too much. As a result, the surface of the food becomes dry (too dry), and the baking state is poor. turn into.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and an object of the present invention is to provide a heating cooker capable of improving the heating efficiency, quickly performing baking cooking, and improving the baking state of food. .

[Structure of the Invention] (Means for Solving the Problems) A cooking device of the present invention includes a cooking chamber, a heater for heating food stored in the cooking chamber by radiant heat,
A cooling fan disposed in the machine room to ventilate the cooking chamber, and when a predetermined condition is satisfied during the process of increasing the temperature of the cooking chamber after the heater is energized, the cooling fan is temporarily stopped. To discharge gas such as steam generated from the food to the outside of the cooking chamber.

In this case, a timer may be provided for starting the timekeeping operation simultaneously with the start of energization of the heater, and the cooling fan may be temporarily operated when the time measured by the timer reaches the set time. .

Alternatively, a configuration may be adopted in which a temperature detection unit for detecting the temperature in the cooking chamber is provided, and after the power supply to the heater is started, the cooling fan is temporarily operated based on the temperature detected by the temperature detection unit.

Alternatively, gas detection means for detecting gas such as steam generated from food in the cooking chamber is provided, and after the power supply to the heater is started, the cooling fan is temporarily operated based on the detection result of the gas detection means. May be configured.

(Operation) After the power supply to the heater is started, the temperature in the cooking chamber rises, and when the temperature rises to some extent, gas such as steam is generated from the food, and the cooking chamber is filled. Therefore,
When a predetermined condition is satisfied during the process of increasing the temperature in the cooking chamber, a cooling fan arranged in the machine room is temporarily operated to discharge gas such as steam generated from food to the outside of the cooking chamber. . Thereby, the radiant heat of the heater reaches the food well. In this case, the operation of the cooling fan is only performed temporarily when a large amount of steam or the like starts to be generated from the food while the temperature in the cooking chamber is rising, so that the cooking chamber is excessively dried or hot air is discharged. The inconvenience of being over-executed can be eliminated.

If the operation start condition of the cooling fan is determined by the time counting operation of the timer means, the configuration is simple and the cost can be reduced.

In addition, if the operation start condition of the cooling fan is determined based on the detection temperature of the temperature detection unit that detects the temperature in the cooking chamber or the detection result of the gas detection unit that detects gas such as steam generated from food, Even if the rate of temperature rise in the cooking chamber changes due to differences in the type of food and outside temperature, etc., it is possible to accurately detect the time when a large amount of steam or the like starts to be generated from food during the temperature rise. In addition, the ventilation device can be operated at the optimal time.

(Example) Hereinafter, a first example in which the present invention is applied to a microwave oven with a heater will be described.
An embodiment will be described with reference to FIG. 1 to FIG. First, the overall configuration will be described with reference to FIG. 2 (longitudinal side view) and FIG. 3 (transverse sectional view). Outer box of microwave oven 1
The oven storage 3 which comprises the cooking chamber 2 is arrange | positioned inside. As shown in FIG. 3, a machine room 4 is defined on the right side of the oven storage 3, and a magnetron 5 and a blower fan 6 serving as a cooling fan are provided in the machine room 4 so as to be located in front and behind. The wind blown from the blower fan 6 is supplied into the heating cooking chamber 2 from the blow hole 8 on the right side of the oven storage 3 through the duct 7 while cooling the magnetron 5. On the other hand, an oven heater 9 is annularly disposed behind the oven storage 3, and a hot air circulation fan 10 is provided on the inner peripheral side of the heater 9. When the oven is cooked, the hot air circulation fan 10 is rotated, and the hot air generated around the heater 9 is supplied into the heating cooking chamber 2 from the hot air holes 11 on the back of the oven storage 3.

As shown in FIG. 2, a grill heater 12 is provided on the upper surface of the oven storage 3, and the heat of the heater 12 is radiated into the cooking chamber 2. In the middle stage of the cooking chamber 2, a food placing shelf 14 for placing a food 13 such as fish is provided so as to be able to be taken in and out.

On the other hand, an exhaust hole 15 is formed on the left side surface of the oven chamber 3, and during the ventilation operation (when the blower fan 6 rotates), the exhaust air discharged from the exhaust hole 15 is formed on the left side surface of the oven chamber 3. The air is discharged from the exhaust port 17 on the back of the outer box 1 through the exhaust duct 16. An oxidation catalyst 18 for deodorization is provided in the exhaust duct 16. As shown in FIG. 4, the oxidation catalyst 18 is formed in a porous shape and has an infinite number of through holes 19, and in the process of passing exhaust gas through the through holes 19, odor components in the exhaust gas are oxidized and decomposed. Deodorized. In this case, a heater 20 is added to the oxidation catalyst 18, and the heater 20 heats the oxidation catalyst 18 to an activation temperature (250 ° C. or higher), thereby activating the oxidation catalyst 18 and deodorizing (oxidizing). To increase.

As shown in FIG. 3, a door 21 for opening and closing the cooking chamber 2 and an operation panel 22 are provided on the left and right sides of the front of the outer box 1, and operation keys (not shown) of the operation panel 22 are provided. By operation, the control circuit 23 in the machine room 4 controls the operation of each heater 9, 12, 20 and each fan 6, 10. In this embodiment, the control circuit 23 includes timer means (not shown), and when performing grill cooking (cooking for baking the food 13 by radiant heat of the heater 12 for the grill), the timer means supplies the heater 12 with heat. A timekeeping operation is started at the same time as the energization start (cooking start), and when the timed time reaches a set time (for example, 5 minutes), it is determined that a predetermined condition is satisfied, and the blower fan 6 is rotated for, for example, 2 minutes. Then, the inside of the cooking chamber 2 is ventilated. As described above, the reason why the blower fan 6 is temporarily operated 5 minutes after the start of cooking is that, as shown in FIG. As a result, a large amount of gas such as steam starts to be generated from the food 13 and fills the cooking chamber 2. And
The reason why the operation of the blower fan 6 is stopped, for example, in 2 minutes is that if the ventilation in the cooking chamber 2 is performed for about 2 minutes, the filled gas in the cooking chamber 2 can be exhausted once, and the ventilation is performed for a longer time. Then, even hot air is discharged to the outside, and the temperature rise in the heating cooking chamber 2 is slowed down, the heating efficiency is reduced, and the cooking time is lengthened. Further, when, for example, 12 minutes have elapsed from the start of cooking, the operation of the blower fan 6 is restarted, and thereafter, the ventilation in the heating cooking chamber 2 is continuously performed until the cooking is completed. The reason for this is that, after about 12 minutes have elapsed from the start of cooking, the temperature in the cooking chamber 2 becomes high at 200 ° C. or more. This is because the heating efficiency does not decrease so much and the heating efficiency is not impaired. However, the air volume at the time of grill cooking is reduced to, for example, about 70% of the air volume at the time of microwave heating. The air volume is switched by changing the on / off duty ratio of energization to the drive motor 6a of the blower fan 6.

By the way, how to emit gas such as steam and the degree of burning
In this embodiment, the operation start time, operation time, and air volume of the blower fan 6 are changed for each cooking menu. For example, in a cooking menu in which smoke or the like is less likely to occur, the operation time of the blower fan 6 is shortened and the air volume is also reduced.

Unlike the above embodiment, when the ventilation operation is started simultaneously with the start of cooking, even the hot air in the heating cooking chamber 2 is continuously discharged. Therefore, as shown by a dashed line in FIG. The rise is slow, and not only does the cooking time take longer, but also the cooking chamber 2 becomes too dry,
In this case, the surface of the food 13 is dried out (excessively dried), and the baking state is also deteriorated.

In this regard, in the first embodiment, in the process of increasing the temperature in the cooking chamber 2, it is only necessary to temporarily perform the ventilation operation for a minimum necessary time when a large amount of steam or the like starts to be generated from the food 13. Therefore, it is possible to eliminate the inconvenience that the inside of the cooking chamber 2 is dried too much or the hot air is discharged too much, and efficiently radiate the radiant heat of the heater 12 to the food 13 while quickly raising the temperature in the cooking chamber 2. As a result, the cooking time can be shortened, and the surface of the food 13 can be prevented from being in a dry state, so that the baked state can be improved. still,
After the inside of the heating cooking chamber 2 has reached a sufficiently high temperature (for example, 12 minutes after the start of cooking), the surface of the food 13 becomes browned and the generation of steam is reduced by that time. After that, even if the blower fan 6 is continuously operated to discharge the oil smoke generated from the food 13, the water on the surface of the food 13 is not deprived too much. The baking state can be improved while improving the condition and increasing the heating efficiency.

By the way, during the ventilation operation, the rotation of the blower fan 6 causes the air in the cooking chamber 2 to pass through the exhaust duct 16 and the exhaust port 17.
However, in the process in which the exhaust gas passes through the oxidation catalyst 18 in the exhaust duct 16, the odor component in the exhaust gas is oxidized and decomposed to become odorless. In order to enhance this oxidation action (deodorization action), it is necessary to heat the oxidation catalyst 18 to 250 ° C. or more to activate it. For example, simply heating the oxidation catalyst 18 with the heater 20 while the ventilation operation is stopped. Then, as shown in FIG. 5 (b), the temperatures of the portions B and C (FIG. 4) remote from the heater 20 do not reach the activation temperature (250 ° C. or higher), and the activation is partially insufficient. Therefore, a sufficient deodorizing effect cannot be obtained.

In this regard, in the first embodiment, during the deodorizing operation (during the ventilation operation).
Since the oxidation catalyst 18 is heated not only by the heat of the heater 20 but also by the exhaust heat, as shown in FIG. 5 (a), the entire oxidation catalyst 18 has an activation temperature (over 250 ° C.) It is heated and becomes evenly activated. Therefore, the odor components in the exhaust gas can be efficiently oxidized and decomposed to improve the deodorizing effect, and the heat capacity of the heater 20 can be reduced by utilizing the exhaust heat.

Moreover, in the first embodiment, since the operation time of the blower fan 6 is determined by the timer means, there is an advantage that the configuration is extremely simple and the cost can be reduced.

However, the present invention is not limited to the configuration using the timer means as in the above-described first embodiment. For example, the present invention is not limited to the configuration as in the second embodiment of the present invention shown in FIG. 6 to FIG. You may. That is, a thermistor 24 is provided as a temperature detecting means for detecting the temperature in the cooking chamber 2, and based on an output signal (detected temperature) of the thermistor 24, a microcomputer (not shown) according to a control program shown in FIG. Control is performed as follows. During grill cooking, heater
After the power supply to the power supply 12 is started, the operation (ventilation operation) of the blower fan 6 is not performed until the temperature detected by the thermistor 24 reaches the set temperature (for example, 90 ° C.) (steps P1 and P2). The reason for this is that when the temperature detected by the thermistor 24 is equal to or lower than the set temperature (90 ° C.), as shown in FIG.
This is for accelerating the temperature rise in the cooking chamber 2 without performing the ventilation operation since the temperature is 100 ° C. or less and a large amount of gas such as steam has not yet been generated from the food 13. Thereafter, when the temperature detected by the thermistor 24 exceeds the set temperature (90 ° C.) (at this time, the temperature in the cooking chamber 2 exceeds 100 ° C.)
The ventilation fan 6 is rotated, for example, only for 2 minutes to ventilate the inside of the cooking chamber 2 (steps P3 to P5). After ventilation, only the heater 12 is energized again to accelerate the temperature rise in the cooking chamber 2, and thereafter, when the temperature detected by the thermistor 24 exceeds 200 ° C. (at this time, the temperature in the cooking chamber 2 becomes lower). Then, the fan 6 is driven again to ventilate the inside of the cooking chamber 2 (steps P6 and P7). Thereafter, when a predetermined cooking time T has elapsed, the heater 12 is turned off, the blower fan 6 is stopped, and grill cooking is completed (steps P8 and P9). Also in the second embodiment, the operation start temperature, the operation time, and the air volume of the blower fan 6 are changed for each cooking menu, so that appropriate cooking can be performed for each cooking menu.

According to the second embodiment, since the operation of the blower fan 6 is controlled based on the temperature detected by the thermistor 24, the inside of the cooking chamber 2 may vary depending on the type of the food 13 or the difference in the outside air temperature. Even if the temperature rise rate changes,
The temperature (temperature) at which a large amount of steam or the like starts to be generated from the food 13 while the temperature is rising can be accurately detected, and the blower fan 6 can be operated at the optimal time, and the type of the food 13 and the outside air temperature can be controlled. Adaptive and optimal control is possible.

9 to 11 show a third embodiment of the present invention. In the third embodiment, in addition to the thermistor 24,
A humidity sensor 25 is provided in the exhaust duct 16 as gas detection means for detecting gas (especially steam) generated from the food 13, and based on an output signal of the humidity sensor 25, a microcomputer (not shown) operates as shown in FIG. Is controlled as follows according to the control program of During grill cooking, after the power supply to the heater 12 is started (step P1), the peak value Vsmax of the output signal of the humidity sensor 25 is read (step P2). After this,
As the temperature in the cooking chamber 2 rises, steam is gradually generated from the food 13 and the humidity in the cooking chamber 2 rises, so that the output voltage Vs of the humidity sensor 25 becomes as shown in FIG. Decreases gradually. Therefore, based on the output decrease amount (Vsmax−Vs) from the output peak value Vsmax of the humidity sensor 25,
In order to determine the operation start time of the blower fan 6, a step
In P3, output decrease amount of humidity sensor 25 (Vsmax-Vs)
Is greater than or equal to a constant α. When the temperature in the cooking chamber 2 rises to about 100 ° C. and a large amount of steam starts to be generated from the food 13, Vsmax−Vs> α. Rotate for 2 minutes to ventilate the cooking chamber 2 (Step P3 ~
P6). After the ventilation, only the heater 12 is energized again to accelerate the temperature rise in the cooking chamber 2, and then, when the temperature detected by the thermistor 24 exceeds 200 ° C.
When the temperature in the inside exceeds 220 ° C.), the blowing fan 6 is driven again to ventilate the inside of the cooking chamber 2 (steps P7 and P8). Thereafter, when a predetermined cooking time T has elapsed, the heater 12 is turned off, the blower fan 6 is stopped, and grill cooking is completed (steps P9 and P10). Also in the third embodiment, the constant α for determining the start of the operation of the blower fan 6, the operation time, and the air volume are changed for each cooking menu, whereby appropriate cooking is performed for each cooking menu. I'm trying to get.

In the third embodiment, the start time of the operation of the blower fan 6 is controlled based on the output signal of the humidity sensor 25. Even if the rate of rise of the temperature in the cooking chamber changes and the degree of generation of steam changes, it is possible to accurately detect the time when a large amount of steam or the like starts to be generated from the food 13 while the temperature in the cooking chamber 2 is rising, The blower fan 6 can be operated at an optimal time, and optimal control suitable for the type of the food 13 and the outside temperature can be performed.

In both the second and third embodiments, the operation stop time of the blower fan 6 is uniformly determined by the timer means. However, the operation stop time of the blower fan 6 is also determined by the temperature detection means. (Thermistor 24) or the output signal of the gas detection means (humidity sensor 25) may be used for the determination.

In addition, various modifications are possible, such as applying the present invention to an electric oven without a range heating function, or adopting a configuration in which the oxidation catalyst 18 is omitted.

[Effects of the Invention] As is apparent from the above description, the present invention provides a cooling device disposed in a machine room when a predetermined condition is satisfied during the process of increasing the temperature in the cooking chamber after the start of energization of the heater. Since the gas such as steam generated from the food is discharged to the outside of the cooking chamber by temporarily operating the fan, it is possible to eliminate the inconvenience that the cooking chamber is too dry or the hot air is discharged too much. By irradiating the radiant heat of the heater efficiently to the food while quickly raising the temperature in the cooking chamber, the cooking time can be shortened, and the food surface can be prevented from becoming dry, The rising condition can be improved.

In this case, if the operation start condition of the cooling fan is determined by the time counting operation by the timer means, the configuration is simple and the cost can be reduced.

In addition, if the operation start condition of the cooling fan is determined based on the detection temperature of the temperature detection unit that detects the temperature in the cooking chamber or the detection result of the gas detection unit that detects gas such as steam generated from food, Even if the rate of temperature rise in the cooking chamber changes due to differences in the type of food and outside temperature, etc., it is possible to accurately detect the time when a large amount of steam or the like starts to be generated from food during the temperature rise. In addition, the cooling fan can be operated at an optimal time, and optimal control suitable for the type of food and the outside temperature can be performed.

[Brief description of the drawings]

1 to 5 show a first embodiment of the present invention. FIG. 1 is a diagram showing a relationship between a temperature change in a heating cooking chamber during grill cooking and an operation of a blower fan. Fig. 3 is an overall longitudinal sectional side view, Fig. 3 is a transverse sectional view of the same, Fig. 4 is a front view of an oxidation catalyst and a heater for heating the oxidation catalyst, and Figs. 5 (a) and 5 (b).
FIG. 4 is a diagram for explaining the relationship between the temperature of each part of the oxidation catalyst and the operation of the blower fan. 6 to 8 show a second embodiment of the present invention. FIG. 6 is a plan view showing a main part cut away, and FIG. 7 is a diagram showing the temperature detected by a thermistor and the operation of a blower fan. FIG. 8 is a flowchart showing a control program. On the other hand, FIGS.
FIG. 11 shows a third embodiment of the present invention. FIG. 9 is a plan view showing a main part cut away, and FIG. 10 is an output voltage of a temperature and humidity sensor in a cooking chamber and operation of a blowing fan. FIG. 11 is a flowchart showing a control program. In the drawing, 2 is a cooking chamber, 4 is a machine room, 5 is a magnetron, 6 is a blower fan (cooling fan), 9 is a heater for an oven, 12 is a heater for a grill, 13 is food, 13 is an exhaust duct, 18 is an oxidation catalyst, 20 is a heater for heating the catalyst, 23 is a control circuit, 24 is a thermistor (temperature detecting means), and 25 is a humidity sensor (gas detecting means).

Continuation of front page (56) References JP-A-1-219426 (JP, A) JP-A-63-131925 (JP, A) JP-A-57-120032 (JP, A) JP-A-55-111095 (JP, A) JP-A-58-158428 (JP, A) JP-A-55-160233 (JP, A) JP-A-52-129791 (JP, U) JP-A-61-69708 (JP, U) JP-A 57-120905 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) F24C 1/02 310 F24C 7/02 350

Claims (4)

(57) [Claims] 1. A heating room, a heater for heating food contained in the cooking room by radiant heat, and a cooling fan disposed in a machine room for ventilating the cooking room, and starting energization of the heater. Thereafter, when a predetermined condition is satisfied during the process of increasing the temperature in the cooking chamber, the cooling fan is temporarily operated to discharge gas such as steam generated from the food to the outside of the cooking chamber. A cooking device characterized by having a configuration as described above. And a timer means for starting a timekeeping operation simultaneously with the start of energization of the heater, wherein the cooling fan is temporarily operated when the timekeeping operation of the timer means reaches a set time. The heating cooker according to claim 1, wherein: 3. A temperature detecting means for detecting a temperature in the cooking chamber, wherein after a power supply to the heater is started, a cooling fan is temporarily operated based on a temperature detected by the temperature detecting means. The heating cooker according to claim 1, wherein 4. A gas detecting means for detecting a gas such as steam generated from food in a cooking chamber, and after a power supply to a heater is started, a cooling fan is temporarily operated based on a detection result of the gas detecting means. The cooking device according to claim 1, wherein the cooking device is configured to perform heating.