JP7287878B2 - heating cooker - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating cooker provided with a hot air unit for supplying hot air into a cooking chamber to heat and cook food.

As this type of heating cooker, for example, Patent Document 1 discloses a cooking chamber containing an object to be cooked, a hot air unit for heating the object to be cooked by hot air convection, and a thermistor for detecting the temperature in the cooking chamber. The hot-air unit comprises a hot-air heater for heating air, a hot-air heater driving means for turning on and off the hot-air heater, a hot-air fan for sending and circulating the heated air in the cooking chamber, and the hot-air fan in a predetermined direction. and a hot air motor that rotates in the air.

JP 2017-194174 A

In the conventional heating cooker such as the microwave oven of Patent Document 1, the temperature inside the cooking chamber is uneven in the saturated state at the set temperature, and the temperature change is large. This has been a factor causing variations in the burnt color of the food to be cooked.

FIG. 14 is a timing chart showing changes in temperature in the cooking chamber when oven heating is performed in a conventional heating cooker. In the conventional heating cooker, the temperature _Tp in the cooking chamber is the set temperature. When the thermistor detects that the temperature is 200°C, the hot-air heater driving means cuts off the entire hot-air heater, and when the thermistor detects that the temperature _Tp in the cooking chamber has fallen below 200°C, the hot-air heater driving means energizes the entire hot-air heater. Due to the temperature control (see FIG. 9), _Tp overshoots up to about 230°C at maximum, and the amount of overshoot from the set temperature was large. As a result, it took about 15 minutes to reach a saturated state after convergence and stabilization at 200°C. In addition, since the entire hot-air heater is configured to turn on and off, frequent turn-on and turn-off may cause voltage flicker due to the application and cut-off of the input voltage applied to the hot-air heater. Accurate hot air heater control was not possible.

In addition, the food to be cooked is originally cooked in a stone kiln, and the flame from the firewood that is the fuel inside the stone kiln, that is, the firewood flame gently shakes the food to bake the food, so that the food can be baked deliciously. is said to be possible. Therefore, stone kiln is characterized by small temperature change and large heat capacity, and there is a problem that the place near the flame is overheated and the place far from the flame is underheated. However, the firewood flame in the stone kiln fluctuates irregularly, and it is possible to add an appropriate accent to the heating of the food being cooked. A freshness can be added to the texture. On the other hand, conventional heating cookers have less unevenness in temperature than stone ovens, but have the problem of large temperature changes as described above. It was not possible to add an appropriate accent to the heating for.

Therefore, in view of the above circumstances, the present invention suppresses the occurrence of voltage flicker, quickly stabilizes the convergence at the set temperature to bring it to a saturated state, and suppresses the temperature change in the saturated state at the set temperature in the cooking chamber. A first object is to provide a cooker.

A second object of the present invention is to provide a heating cooker capable of adding an appropriate accent to the heating of the food to be cooked.

The present invention comprises a cooking chamber containing an object to be cooked, oven heating means for heating the object to be cooked by hot air convection, internal temperature detecting means for detecting the temperature in the cooking chamber, and the object to be cooked. a cooking control unit for controlling the oven heating means to cook at a set temperature, the oven heating means comprising a main heater, a sub-heater, and a hot air heater driving means; The electric power value is higher than the electric power value of the sub-heater, and after the temperature in the cooking chamber reaches a first threshold value below the set temperature, the temperature exceeds the set temperature by a predetermined temperature. 2, the cooking controller sends a control signal to the hot-air heater drive means so as to PWM-control the sub-heater while maintaining the energization of the main heater. When the temperature of the hot air exceeds the second threshold, the cooking control unit sends a control signal to the hot air heater driving means so as to cut off the power to both the main heater and the sub-heater. do.

According to the invention of claim 1, since the hot air heater that is PWM-controlled is only a sub-heater with a low electric power value, it is possible to suppress the occurrence of voltage flicker due to the application and interruption of the input voltage applied to the hot air heater. . In addition, since the amount of overshoot of the temperature in the cooking chamber from the set temperature can be suppressed, it is possible to rapidly converge and stabilize at the set temperature and reach a saturated state. In addition, it is possible to suppress the temperature change in the saturation state at the set temperature in the cooking chamber.

According to the invention of claim 2, the heating of the sub-heater controlled by PWM varies irregularly like "1/f fluctuation", and the temperature inside the refrigerator is not made constant, so that the fluctuation of the firewood flame is reproduced, Since an appropriate accent can be added to the heating of the food to be cooked, the quality of the food to be cooked can be appropriately changed each time the food is cooked, and freshness can be added to the taste and texture.

According to the invention of claim 3, the mist is instantly vaporized into superheated steam, and the food to be cooked in the cooking chamber is heated by moderate water molecules (superheated steam). Therefore, the amount of temperature change is suppressed and uniformed, and the surface can be baked crisply while adding an appropriate accent to the heating of the food to be cooked.

According to the invention of claim 4, the number of revolutions of the phase-controlled hot air fan is irregularly changed like "1/f fluctuation", and the fluctuation of the firewood flame is reproduced by not making the internal temperature constant. Since the heating of the food to be cooked can be appropriately accented, the finish of the food to be cooked can be appropriately changed each time cooking is performed, and freshness can be added to the taste and texture.

BRIEF DESCRIPTION OF THE DRAWINGS It is an external perspective view of the heating cooker which shows the 1st Embodiment of this invention. Same as the above, it is the figure seen from the front front when the door was opened. Fig. 3 is a vertical cross-sectional view of the same as above, viewed from the side; Fig. 3 is a front front view of the same, with the cabinet and the oven rear plate removed; Fig. 2 is a vertical cross-sectional view of the microwave generator and its surroundings viewed from the side; Fig. 3 is a schematic diagram showing the internal structure of the main body of the same; FIG. 2 is a block diagram showing a main electrical configuration of the same; FIG. 4 is a circuit diagram of a main part related to the operation of the hot air heater; Fig. 10 is a timing chart showing changes in temperature in the cooking chamber and voltage input to the hot air heater when oven heating is performed by the conventional heating cooker and the heating cooker of the first embodiment of the present invention. It is a circuit diagram of the main part related to the operation of the hot air heater of the heating cooker showing the second embodiment of the present invention. It is a timing chart showing transition of the temperature in the cooking chamber and the voltage input to the hot air heater when oven heating is performed by the conventional heating cooker and the heating cooker of the second embodiment of the present invention. FIG. 11 is a circuit diagram of the essential parts related to the operation of the hot air fan of the heating cooker showing the third embodiment of the present invention. In the conventional heating cooker and the heating cooker of the third embodiment of the present invention, changes in the temperature in the cooking chamber when oven heating, the rotation speed of the hot air fan, and the voltage input to the hot air heater are shown. It is a timing chart showing. Fig. 2 shows the changes in the internal temperature of the cooking chamber and the voltage input to the hot air heater when performing steam heating using mist superheated steam in the conventional heating cooker and the heating cooker of the fourth embodiment of the present invention. It is a timing chart. 1 is a timing chart showing changes in internal temperature in a cooking chamber during oven heating in a conventional heating cooker.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

First, based on FIGS. 1 to 7, the overall configuration of the first embodiment of the microwave oven as the cooking device of the present invention will be described. , a metal cabinet 2 is provided as a member for covering the outer shell of the microwave oven as a product. A door 3 is provided on the front surface of the main body 1 and can be opened and closed.

The upper part of the door 3 is provided with a handle 4 for opening and closing the door 3, which opens and closes vertically. It has The operation panel unit 5 is provided with a display unit 6 for displaying cooking settings, progress, etc., and an operation unit 7 for enabling various operation inputs related to heat cooking. An operation panel PC (printed circuit) board (not shown) is arranged behind the operation panel unit 5 inside the door 3 in order to control the display means 6, the operation means 7, and the like.

At the lower part of the main body 1, a water supply cassette 8 and a water receiver 9 which can be attached and detached from the front surface of the main body 1 are arranged. The water supply cassette 8 is a bottomed container for containing liquid water as a supply source of mist ejected from a mist supply device 43 which will be described later. The water receiver 9 is a bottomed container that receives food waste, water droplets, steam, etc. from the main body 1 .

A cabinet 2 forming the left and right side surfaces and the upper surface of the main body 1 includes an oven front plate 12 forming the front surface of the main body 1 and a rear surface of the main body 1 so as to cover the main body 1 and the oven bottom plate 11 forming the bottom surface of the oven range. It is provided between the oven rear plate 13 to be formed. Further, the main body 1 is provided with a cooking chamber 14 in which an object to be cooked S to be heated and cooked, and a thermistor 15 as a temperature detecting element for detecting the temperature of the cooking chamber 14 . The front surface of the cooking chamber 14 reaches the oven front plate 12 and has an opening for taking in and out the food S to be cooked, and the opening is opened and closed by a door 3. - 特許庁A thermistor 15 serving as a chamber internal temperature detecting means is arranged in the vicinity of the door 3 inside the cooking chamber 14 . In addition, the thermistor 15 of this embodiment is designed so that 1 digit is several degrees Celsius by limiting the detection width. ing.

A peripheral wall forming the inner surface of the cooking chamber 14 is composed of a ceiling wall 14a, a bottom wall 14b, a left wall 14c, a right wall 14d, and an inner wall 14e. A back wall 14e of the cooking chamber 14 has a suction port 16 at its center, and a plurality of outlets 17 around the suction port 16.例文帳に追加An upper heater 18 for grilling is provided on the upper part of the main body 1 so as to radiately heat the food S to be cooked from above the cooking chamber 14, facing the dome-shaped ceiling wall 14a serving as the upper wall surface of the cooking chamber 14. A microwave generator 19 including a magnetron is provided at the bottom of the main body 1 to supply microwaves, which are radio waves, into the cooking chamber 14 . As a result, the object to be cooked S stored in the cooking chamber 14 is grill-heated from above by heat radiation accompanying the energization of the upper heater 18 , and the energization of the microwave generator 19 causes the interior of the cooking chamber 14 to be heated. Microwaves are radiated to the object S to be cooked which is housed in the container, and the object to be cooked S is microwave-heated. As will be described later, in addition to the thermistor 15, there is also a temperature sensor near the position where the food S is placed, for example, the center of the lower part of the left side wall 14c or the right side wall 14d or the bottom wall 14b near the position where the food S is placed. A thermistor serving as a detection element may be provided, and as will be described later, the temperature information in the vicinity of the object to be cooked S may be fed back more quickly and accurately from the thermistor.

A left side wall 14c and a right side wall 14d of the cooking chamber 14 are provided with a pair of left and right shelf supports 22 in two stages in order to store and hold a metal square plate 21 in a suspended state inside the cooking chamber 14. there is The square plate 21 used here has a bottomed concave shape with an open top, and is formed by a housing portion 21A formed without holes in the rest, and a flange portion 21B extending horizontally outward from the upper end of the housing portion 21A. Configured. A vent hole 21C is formed in the flange portion 21B to allow hot air to flow through the square plate 21. As shown in FIG. FIG. 2 shows a state in which the flange portion 21B of the square plate 21 is placed on the lower shelf support 22 inside the cooking chamber 14, and the object to be cooked S is placed on the storage portion 21A. The plate 21 may be placed only on the upper shelf support 22, or two square plates 21 may be placed on the upper and lower shelf supports 22 respectively. Other accessories such as may be accommodated and held. Further, in the range heating by the microwave generator 19 described above, the object to be cooked S can be microwave-heated inside the cooking chamber 14 without placing the square plate 21 or the gridiron inside the cooking chamber 14 (Fig. not shown) and can be cooked.

Numeral 24 denotes a hot air unit for oven heating provided inside the main body 1 from the rear to the bottom outside the cooking chamber 14 . The hot air unit 24 serves as means for heating the object S to be cooked, and includes a convex casing 26 attached to the back wall 14e, a hot air heater 27 for heating air, and a heated air that is fed into the cooking chamber 14 and circulated. A hot air fan 28 , an electric hot air motor 29 that rotates the hot air fan 28 in a predetermined direction, and a transmission mechanism 30 that transmits the driving force from the hot air motor 29 to the hot air fan 28 . A hot-air heater 27 and a hot-air fan 28 are respectively disposed in a heating chamber 31 formed in the exterior rear of the cooking chamber 14 as an internal space between the inner wall 14e and the casing 26. A hot air motor 29 is disposed in a lower space 32 between the cooking chamber 14 and the oven bottom plate 11 . An oven rear plate 13 is arranged at the rear portion of the main body 1 so as to cover the entire hot air unit 24 from the outside of the rear side.

The hot-air fan 28 of this embodiment is provided as a so-called centrifugal fan that takes in air in the axial direction and discharges it in a radial direction perpendicular to the axial direction by centrifugal force during rotation. It is arranged around 28 radial directions. The hot air heater 27, which is also a heat generating part, uses, for example, a sheathed heater, a mica heater, a quartz tube heater, a halogen heater, or the like. The suction port 16 and the hot air outlet 17 described above function as a ventilation section that communicates between the cooking chamber 14 and the heating chamber 31 .

In the present embodiment, when the hot-air fan 28 is driven to rotate as the hot-air motor 29 is energized, the air sucked from the inside of the cooking chamber 14 through the suction port 16 is blown out in the radial direction of the hot-air fan 28, thereby energizing the hot-air fan 28. Heated by the hot air heater 27 , the hot air passes through the outlet 17 and is supplied into the cooking chamber 14 . As a result, a path for circulating hot air inside and outside the cooking chamber 14 is formed, and the object to be cooked S in the cooking chamber 14 is heated by hot air convection.

Next, as a heating means for heating the object S to be cooked, the microwave generator 19 as a microwave heating means and the detailed structure around it will be described. The bottom wall 14b of the cooking chamber 14 is constructed by covering the top opening of a recessed antenna housing portion 35 formed in a metal plate member 34 with a bottom plate 36 such as a ceramic plate through which microwaves can pass. The metal plate material 34, which is impermeable to microwaves, integrally forms not only the peripheral portion of the bottom wall 14b, but also the left side wall 14c, the right side wall 14d, and the inner wall 14e. The inner surface of is made entirely of a microwave-impermeable material.

The microwave generator 19 includes a magnetron (not shown) serving as a microwave supply source, and a conductor in the lower space 32 inside the main body 1 that guides the microwaves oscillated by the magnetron directly below the antenna housing portion 35 . A wave tube 37, an antenna motor 38 disposed below the waveguide 37, and an antenna holder 39 whose lower end portion is disposed inside the waveguide 37 and is attached and fixed to the rotating shaft of the antenna motor 38. , a cylindrical cable shaft 40 inserted and fixed in the antenna holder 39, and an antenna 41 to which the upper end of the cable shaft 40 is attached and fixed at the center thereof and which is rotatably provided inside the antenna housing portion 35. Mainly composed of When the top opening of the antenna housing portion 35 is closed with the bottom plate 36 , the entire antenna 41 is arranged in parallel with the flat plate-like bottom plate 36 forming the bottom wall 14 b of the cooking chamber 14 .

A mist supply device 43 for feeding mist into the cooking chamber 14 includes, in addition to the water supply cassette 8 described above, a nozzle 45 for turning the supplied liquid water into mist, and a nozzle 45 connected between the water supply cassette 8 and the nozzle 45 . , a water supply pump 47 that guides water from the water supply cassette 8 to the nozzle 45 , and a plurality of mist ejection holes 44 that communicate with the nozzle 45 . As a result, while the mist supplying device 43 is in operation, the water from the water supply cassette 8 is sent to the nozzle 45 by the water supply pump 47, and the water supplied by this nozzle 45 is turned into mist, and the mist is discharged from the mist ejection hole 44 into the cooking chamber 14. supplied internally. At this time, if the temperature in the cooking chamber 14 is higher than 100 degrees Celsius at atmospheric pressure (hereinafter, the temperature value is the temperature value in Celsius at atmospheric pressure), this mist will instantly be generated in the cooking chamber 14 By evaporating into superheated steam, the object to be cooked S placed in the cooking chamber 14 is quickly and evenly heated with appropriate water molecules (superheated steam).

FIG. 7 illustrates the main electrical configuration of the microwave oven. In the figure, reference numeral 51 denotes a control means constituted by a microcomputer. As is well known, the control means 51 includes a CPU as arithmetic processing means, a memory as storage means, a timer as timekeeping means, an input Equipped with an output device.

In the input port of the control means 51, in addition to the operation means 7 using the keys and the touch panel described above, an infrared sensor 53A serving as a detection element is equipped with a swing mechanism to detect the temperature distribution in the entire cooking chamber 14. Thus, the object temperature detection means 53 for detecting the surface temperature of the object S stored therein by the infrared sensor 53A, and the temperature inside the cooking chamber 14 such as the thermistor 15 for detecting the temperature inside the cooking chamber 14 are detected. means 54, hot air motor rotation detecting means 55 for detecting the rotation of the hot air motor 29, door open/close detecting means 56 for detecting the open/closed state of the door 3, and the origin position of the antenna constituting the microwave generator 19 is detected. Antenna position detection means 57 are electrically connected to each other.

In addition to the display means 6 described above, the output port of the control means 51 has a microwave heating means 61 including a magnetron of the microwave generator 19 and its driving means, an upper heater 18 for grill heating, and an oven heating means. Heater driving means 62 such as a relay for energizing/disconnecting the hot air heaters 27, antenna driving means 63 for rotationally driving an antenna that radiates microwaves into the cooking chamber 14, and rotational driving for the hot air motor 29. A hot air motor driving means 64 and a pump driving means 65 for operating the water supply pump 47 of the mist supply device 43 are electrically connected to each other.

The control means 51 receives an operation signal from the operation means 7, a cooking object temperature detection means 53, a refrigerator temperature detection means 54, a hot air motor rotation detection means 55, a door open/close detection means 56, and an antenna position detection means. Upon receipt of each detection signal from 57, microwave heating means 61, heater driving means 62, antenna driving means 63, hot air motor driving means 64, and pump driving are performed at predetermined timings based on the clocking means. It has a function of outputting a drive control signal to the means 65 and outputting a display control signal to the display means 6 . These functions are realized by the control means 51 reading a program recorded in the memory as a storage medium. It has a program that works.

The cooking control section 67 mainly controls the operation of each section related to the cooking of the food item S. Upon receiving an operation signal associated with the operation of the operating means 7, a detection signal from the door opening/closing detection means 56 is received. , when it is determined that the door 3 is closed, the microwave heating means 61, the heater driving means 62, the antenna driving means 63, the hot air motor driving means 64, and the pump driving means 65 are operated according to the operation signal. to control the cooking of the food S in the cooking chamber 14 by sending a control signal to . In addition, a plurality of cooking menus are stored in advance in the memory as cooking information including the ingredients of the object S to be cooked and the heating conditions for executing various types of cooking. When the menu selection setting means 7A incorporated in 7 is operated appropriately, one or a plurality of cooking menus selected from among them are set as a specific cooking menu for heat cooking, and a predetermined cooking menu according to the cooking menu is set. It is configured to automatically heat and cook the object S to be cooked according to the procedure.

The menu selection setting means 7A is specifically provided on the surface of the LED display serving as the display means 6, and is a touch key that enables selection of a specific menu from a plurality of menus displayed on the LED display. , when a specific menu is selected by operating the touch key, the specific menu is set and stored by the cooking control unit 67, and the food S to be cooked is processed in a predetermined procedure according to the specific menu. and a start key for starting cooking. This is merely an example, and the configuration of the menu selection setting means 7A is not particularly limited.

Next, the operation of the microwave oven having the above configuration will be described in detail. With the food S to be cooked in advance in the cooking chamber 14, the door 3 is closed while gripping the handle 4, and after a specific cooking menu is selected by the menu selection setting means 7A or the like, the food S to be cooked is placed. When the start of cooking is instructed, a control signal generated corresponding to the selected cooking menu is output at a predetermined timing from the output port of the control means 51 according to the control program incorporated in the memory of the control means 51, The food S is heated and cooked.

Here, for example, when a menu of microwave cooking is selected, the heating control section 67 receives a detection signal from the cooking object temperature detection means 53 and adjusts the antenna so that the cooking object S is heated to the set temperature. Appropriate control signals are sent to the microwave heating means 61 and the antenna driving means 63 while confirming the origin position of the antenna 41 based on the detection signal from the position detecting means 57 . As a result, the magnetron of the microwave generator 19 and the antenna 41 are operated, and the microwaves generated from the surface of the rotating antenna 41 are supplied into the cooking chamber 14, and the food S in the cooking chamber 14 is heated by high frequency. be done.

When the grill cooking menu is selected, the heat cooking control section 67 receives a detection signal from the internal temperature detecting means 54 and causes the heater driving means 62 to heat the inside of the cooking chamber 14 to the set temperature. The power supply to the upper heater 18 is controlled to grill the food S in the cooking chamber 14 from above.

When a steamed dish using mist superheated steam (steam cooking) is selected, the heat cooking control unit 67 receives a detection signal from the internal temperature detection means 54 and heats the interior of the cooking chamber 14 to the set temperature. The heater driving means 62 controls the energization and energization of the upper heater 18 so that the heater 18 is turned on and off. When the cooking controller 67 determines that the internal temperature of the cooking chamber 14 has reached the set temperature, it sends a control signal to the pump driving means 65 to operate the water supply pump 47 incorporated in the mist supply device 43. to supply mist by ejecting water from the mist ejection hole 44 into the cooking chamber 14. - 特許庁At this time, the heat cooking control unit 67 controls the operation of the water supply pump 47 so that the amount of water that can be vaporized at the set temperature in the cooking chamber 14 is equal to or less than the upper limit of the amount of water that can be vaporized at one time. As a result, the inside of the cooking chamber 14 is heated to the set temperature, so the mist is instantly vaporized into superheated steam, and the mist that is not vaporized at this time also contacts one of the walls 14a to 14e of the cooking chamber 14. As a result, the food S in the cooking chamber 14 is quickly and evenly heated with appropriate water molecules (superheated steam). Therefore, it is possible to reduce the wateriness of the food S to be cooked and to bake it deliciously. In addition, since the amount of water W to be used can be reduced by half, the amount of drain can be reduced and almost eliminated, and maintenance of the water receiver 9 and the cooking chamber 14 can be facilitated.

When the mist is supplied to the interior of the cooking chamber 14, the temperature inside the cooking chamber 14 decreases. The cooking control unit 67 determines whether or not the internal temperature of the cooking chamber 14 has reached the set temperature based on the detection signal from the internal temperature detecting means 54. When the cooking control unit 67 determines that the internal temperature has not reached A cooking control unit 67 controls the ON/OFF of the upper heater 18 by the heater driving means 62 so that the inside of the cooking chamber 14 is heated to the set temperature. When the cooking controller 67 determines that the internal temperature of the cooking chamber 14 has reached the set temperature, water is jetted into the cooking chamber 14 as described above to supply mist again. As a result, the mist is instantly vaporized into superheated steam, and the object to be cooked S in the cooking chamber 14 is heated with an appropriate amount of water molecules (superheated steam). can be done. Further, by grilling the food S to be charred, the original deliciousness of the food S can be brought out.

Here, the action when the oven heating menu is selected will be described with reference to FIGS. 8 and 9. FIG. FIG. 8 shows the circuit configuration of the main part particularly related to the operation of the hot air heater 27. As shown in FIG. In the figure, 71 is a cord with a power plug, 72 is a power circuit that generates and outputs an AC voltage from the commercial voltage supplied from the cord with a power plug 71, and the AC voltage from the power circuit 72 is sent to the next stage. It is applied to the hot air heater 27 as an input voltage. The hot-air heater 27 of this embodiment consists of a main heater 27a and a sub-heater 27b. The power value of the main heater 27a is greater than the power value of the sub-heater 27b, and only the sub-heater 27b is PWM-controlled. , the voltage flicker due to the application and interruption of the input voltage applied to the hot air heater 27 is suppressed. In this embodiment, the main heater 27a is 1200 W and the sub-heater 27b is 200 W, but the values are not limited to these values. One end of the main heater 27a and one end of the sub-heater 27b are connected in parallel with one side of the power supply circuit 72 . The other end of the main heater 27a and the other end of the sub-heater 27b are connected to the hot air heater driving means 62a of the heater driving means 62, and the hot air heater driving means 62a is connected to the other side of the power supply circuit 72.

The hot-air heater driving means 62a includes a first switching element 73 made of a relay, a second switching element 74 made of a triac, and an IGBT element for passing a current through the LED element on the light emitting side of the second switching element 74. 75 and a resistor 76, and a PWM control circuit 67a of a heat cooking control section 67 is connected to the hot air heater driving means 62a. Specifically, one end of the first switch element 74 is connected in series with the main heater 27a, and the other end is connected to the other side of the power supply circuit 72. An input voltage is applied to and cut off from the main heater 27a.

One end of the phototriac element on the light receiving side of the second switch element 74 is connected in series with the sub-heater 27b. connected with The cathode of the LED element on the light emitting side of the second switch element 74 is connected to one end of the resistor 76, the anode of this LED element is connected to the emitter of the IGBT element 75, and current flows through the LED element to turn it on. Then, the phototriac element is turned on, the second switch element 74 is turned on, and the input voltage is applied to the sub-heater 27b.

The IGBT element 75 has a collector terminal connected to the terminal Vcc of the Vcc voltage and a gate terminal connected to the PWM control circuit 67a. The other end of the resistor 76 is connected to the ground terminal G, and when a signal from the PWM control circuit 67A is input to the gate terminal of the IGBT element 75, current from the terminal Vcc flows between the collector and the emitter. passes through the phototriac element on the light receiving side of the second switch element 74 and flows to the ground terminal G via the resistor 76 .

The PWM control means 67a receives the detection signal from the internal temperature detection means 54, outputs a PWM control signal to the IGBT element 75 so as to maintain the internal temperature at the set temperature, and activates the hot air heater driving means. At 62a, the sub-heater 27b is PWM-controlled. Further, the PWM control means 67a of this embodiment carries out PWM control with an energization rate of 50% to 100%, and changes the energization rate according to the object S to be cooked. For example, when the object S to be cooked is bread, the power supply rate is 60%, but it is not limited to this value. The cooking control unit 67 controls both the first switch element 73 and the second switch element 74 to be OFF when the inside temperature exceeds the set temperature by a predetermined temperature. On the other hand, when the inside temperature is within the predetermined temperature from the set temperature, the PWM control means 67a controls the input voltage to the main heater 27a while maintaining the first switch element 73 ON. The sub-heater 27b is configured to be PWM-controlled, which suppresses the occurrence of voltage flicker due to the application and interruption of the input voltage, and reduces the change in temperature inside the cooking chamber 14. FIG.

The action when the oven heating menu is selected will be described with reference to FIG. In FIG. 9, _T1 is a graph of the internal temperature of the microwave oven of this embodiment, and _Tp is a graph of the internal temperature of the conventional microwave oven whose temperature is controlled by the hot air heater 27 as a whole. First, the heat cooking control unit 67 receives a detection signal from the internal temperature detection means 54, and controls the heater driving means 62 and the hot air motor driving means 64 so that the inside of the cooking chamber 14 is heated to the set temperature of 200°C. to control the hot-air heater 27 or the main heater 27a and sub-heater 27b, and the hot-air motor 29 (step _S1 ). As a result, the rotational force generated in the hot air motor 29 is transmitted to the hot air fan 28, and the hot air fan 28 rotates inside the heating chamber 31. It is captured. Also, by the rotation of the hot air fan 28, the air sucked into the heating chamber 31 from the cooking chamber 14 through the suction port 16 is sent to the energized hot air heater 27 side, and the heated air is sent to the cooking chamber 14 through the blowout port 17 as hot air. By supplying the hot air, the object to be cooked S in the cooking chamber 14 is heated by hot air convection.

In the microwave oven of the present embodiment, when the heat cooking control unit 67 receives the detection signal from the internal temperature detection means 54 and determines that the internal temperature _T1 has reached the first threshold value _Th1 , the first With the switch element 73 kept ON, a control signal is sent to the hot air heater driving means 62a of the heater driving means 62 so that the sub-heater 27b is PWM-controlled by the PWM control means _67a (step S2). The value of the first threshold _Th1 is preferably set to a value equal to or lower than the set temperature of 200° C. in consideration of the rate of increase of the internal temperature _T1 in step _S1 . As a result, the sub-heater 27b is PWM-controlled while applying the input voltage to the main heater 27a, thereby reducing the change in the internal temperature _T1 in the cooking chamber 14. FIG. Further, since the thermistor 15 as the chamber temperature detection means 54 of the present embodiment has improved resolution, the chamber temperature _T1 can be detected more precisely, and more reliable PWM control of the sub-heater 27b can be performed. . At this time, the thermistor as the internal temperature detecting means 54 is placed near the placement position of the food S to be cooked, such as the lower center of the left side wall 14c or the right side wall 14d, or the vicinity of the placement position of the food S to be cooked on the bottom wall 14b. is provided, information on the temperature near the object to be cooked S can be fed back from the thermistor more quickly and accurately to the cooking control section 67, so that the sub-heater 27b can be PWM-controlled more quickly and accurately.

The cooking control unit 67 receives the detection signal from the internal temperature detection means 54, and the internal temperature _T1 reaches the second threshold value _Th2 , which exceeds the set temperature of 200°C by a predetermined temperature. If so, a control signal is sent to the hot air heater drive means 62a to turn off both the first switch element 73 and the second switch element 74 (step _S3 ). As a result, both the main heater 27a and the sub-heater 27b are cut off, so that the internal temperature _T1 drops.

Thereafter, when the heat cooking control section 67 receives the detection signal from the internal temperature detection means 54 and determines that the internal temperature _T1 has fallen below 200° C., the first switch element 73 is maintained ON again. Then, a control signal is sent to the hot air heater driving means 62a of the heater driving means 62 so that the sub-heater 27b is PWM-controlled by the PWM control means 67a (step _S4 ). As a result, it is possible to suppress the amount of overshoot of the internal temperature from the set temperature, so it is possible to quickly converge and stabilize at the set temperature and reach a saturated state. can be suppressed. When the cooking control unit 67 receives the detection signal from the internal temperature detection means 54 and determines that the internal temperature _T1 has again reached the second threshold value _Th2 , the first switch element 73 is activated again. A control signal is sent to the hot-air heater drive means 62a to turn off both the switch element 74 and the second switch element 74 (step _S5 ). After that, the heating and cooking control section 67 repeats the operations of steps S ₄ to S ₅ described above until the timer as the time measuring means of the control means 51 ends and the oven heating ends.

In FIG. 9, comparing the internal temperature _T1 of the microwave oven of this embodiment with the internal temperature _Tp of the conventional microwave oven whose temperature is controlled by the hot air heater 27 as a whole, it is found that from the set temperature of 200 ° C. The maximum value of the amount of overshoot is approximately 30°C for the internal temperature _Tp of the conventional microwave oven, and approximately 5°C for the internal temperature _T1 of the microwave oven of this embodiment. I was able to confirm that it was suppressed. For this reason, the time to stabilize the convergence at 200 ° C and make it saturated is about 15 minutes for the internal temperature _Tp of the conventional microwave oven, whereas the internal temperature _T1 of the microwave oven of this embodiment is about 15 minutes. It took about 5 minutes, and it was confirmed that the set temperature rapidly converged and stabilized to reach a saturated state. In addition, the temperature change Diff in the saturated state at 200 ° C. is ₈ ° C. while the temperature T _p in the conventional oven range is 23 to 25 ° C. In addition, it was confirmed that the temperature change in the saturation state at the set temperature was suppressed, and the superiority of the microwave oven of the present embodiment was confirmed.

As described above, the microwave oven of the present embodiment includes the cooking chamber 14 containing the object S to be cooked, the hot air unit 24 as an oven heating means for heating the object S by hot air convection, and and _a heating control section 67 for controlling the heater driving means 62 and the hot air motor driving means 64 of the hot air unit 24 so as to cook the food S at the set temperature. The hot-air unit 24 includes a main heater 27a and a sub-heater 27b for heating air, and a hot-air heater driving means 62a for turning on and off the main heater 27a and the sub-heater 27b. After the temperature _T1 in the cooking chamber 14 reaches a first threshold value _Th1 below 200°C, which is the set temperature, a predetermined When the temperature exceeds the second threshold value _Th2 , the cooking control unit 67 controls the hot air heater driving means 62a to PWM-control the sub-heater 27b while maintaining the energization of the main heater 27a. When the signal is sent and the temperature in the cooking chamber 14 exceeds the second threshold value _Th2 , the cooking control unit 67 turns off the power to both the main heater 62a and the sub-heater 62b. It is configured to send a control signal to the

In this case, the hot air heater 27 that is PWM-controlled is only the sub-heater 27b with a low power value, so voltage flicker due to the application and interruption of the input voltage applied to the hot air heater 27 can be suppressed. In addition, since the amount of overshoot of the temperature _T1 in the cooking chamber 14 from 200° C. can be suppressed, it is possible to quickly converge and stabilize at the set temperature and bring it into a saturated state. At the temperature _T1 in the cooking chamber 14, the temperature change Diff in the saturation state at 200° C. can be suppressed.

Further, a thermistor, which is the internal temperature detection means 54 of the present embodiment, may be provided in the vicinity of the position where the object to be cooked S is placed. Since it can be fed back to the cooking control unit 67, the sub-heater 27b can be PWM-controlled more quickly and accurately.

A second embodiment of a microwave oven as a cooking device according to the present invention will be described below with reference to FIGS. 10 and 11. FIG. In this embodiment, in addition to the configuration of the microwave oven of the first embodiment, a fluctuation data storage unit 81 storing fluctuation data of the firewood flame is provided.

FIG. 10 shows the circuit configuration of the main part particularly related to the operation of the hot air heater 27 in this embodiment. It differs from the circuit configuration of the first embodiment described. Other configurations are the same as those of the first embodiment.

The fluctuation data storage unit 81 stores "fluctuation data" corresponding to the fluctuation of the firewood flame. This "fluctuation data" is data of "1/f fluctuation" in which the signal intensity varies irregularly with time. It is said that there are fluctuations in sound that people find comfortable in the natural world. These are known as "1/f fluctuations", which appear to be constant, but have unpredictable irregular fluctuations in them. The firewood flame used in the stone kiln also heats the food by swaying irregularly like "1/f fluctuation" and soothes the human heart. Using the fluctuation data to realize the behavior, the PWM control circuit 67a sets a predetermined heating pattern in which the output of the sub-heater 27b continuously changes and fluctuates irregularly, and according to the set predetermined heating pattern. , the PWM control circuit 67a controls the sub-heater 27b. Therefore, the fluctuation data stored in the fluctuation data storage unit 81 is read into the PWM control circuit 67a and reflected in the PWM control of the sub-heater 27b.

It should be noted that the truly random waveform data may not change its signal intensity irregularly, and may not fluctuate irregularly like "1/f fluctuation". For this reason, the fluctuation data of the present embodiment is preprogrammed with data in which the energization rate, period, etc. are irregularly fluctuated like "1/f fluctuation". remembered.

The operation when the oven heating menu is selected in this embodiment will be described with reference to FIG. 11 . In FIG. 11, _T2 is a graph of the internal temperature of the microwave oven of this embodiment, and _Tp is a graph of the internal temperature of the conventional microwave oven whose temperature is controlled by the hot air heater 27 as a whole. Since the operation of converging and stabilizing the internal temperature of the microwave oven according to the present embodiment to the set temperature of 200° C. until the temperature reaches the saturated state is the same as that of the first embodiment, the explanation is omitted.

Upon receiving the detection signal from the chamber temperature detection means 54, the cooking control unit 67 determines that the temperature change Diff of the chamber temperature _T2 has reached a predetermined value of 8°C or less and has reached saturation at 200°C. Upon determination (place P ₁ ), a control signal is sent to send the fluctuation data stored in the fluctuation data storage section 81 to the PWM control circuit 67a. The PWM control circuit 67a receives the fluctuation data, reads the fluctuation data, and controls the hot air heater driving means 62a of the heater driving means 62 so as to irregularly vary the energization rate of the PWM control of the sub-heater 27b between 50% and 100%. send a control signal to As a result, the heating of the sub-heater 27b controlled by PWM is varied irregularly like "1/f fluctuation", and the inside temperature _T2 is not made constant to reproduce the fluctuation of the firewood flame, and the food to be cooked is cooked. Since an appropriate accent can be added to the heating of the S, the finish of the food S to be cooked can be appropriately changed each time cooking is performed, and freshness can be added to the taste and texture.

When the heat cooking control unit 67 receives a signal from a timer as a timing means and determines that the oven heating has reached the finish time _t1 (place _P2 ), the fluctuation data is stored so as to stop sending the fluctuation data. A control signal is sent to the unit 81 . As a result, the PWM control circuit 67a sends a control signal to the hot air heater driving means 62a so as to perform PWM control as described in the first embodiment, and the temperature _T2 in the refrigerator overshoots from 200°C. is suppressed to suppress the temperature change in the saturated state at 200°C. Therefore, the temperature change Diff of the inside temperature _T2 can be stably reduced, and uneven browning of the food S to be cooked can be eliminated.

As described above, the microwave oven of this embodiment includes the fluctuation data storage unit 81 as a first storage means for storing the fluctuation data in which the cooking control unit 67 converts the "1/f fluctuation" into data. The PWM control circuit 67a of the control unit 67 reads the fluctuation data from the fluctuation data storage unit 81 and sends a control signal to the hot air heater driving means 62a so as to irregularly vary the energization rate of the PWM control of the sub-heater 27b. and

In this case, the heating of the sub-heater 27b, which is PWM-controlled, varies irregularly like "1/f fluctuation", and the inside temperature _T2 is not made constant to reproduce the fluctuation of the firewood flame. Since an appropriate accent can be added to the heating of the object S, the finish of the object S to be cooked can be appropriately changed each time cooking is performed, and freshness can be added to the taste and texture.

Further, the microwave oven of this embodiment further includes a timer as a timing means, and when the oven heating as cooking reaches the finishing time _t1 (location _P2 ), the PWM control circuit 67a changes the fluctuation data storage unit A control signal is sent to the hot-air heater driving means so as to stop reading fluctuation data from 81 and perform PWM control of the sub-heater 27b.

In this case, the amount by which the inside temperature _T2 overshoots the set temperature of 200°C is suppressed, and the temperature change Diff in the saturated state at 200°C is suppressed. Therefore, the temperature change Diff of the inside temperature _T2 can be stably reduced, and uneven browning of the food S to be cooked can be eliminated.

A third embodiment of an oven range as a cooking device according to the present invention will be described below with reference to FIGS. 12 and 13. FIG. In this embodiment, by irregularly varying the number of revolutions of the hot air fan 28, the internal temperature _T3 is not made constant, thereby reproducing the fluctuation of the firewood flame, and heating the object S to be cooked appropriately. adding an accent.

FIG. 12 shows the circuit configuration of the main part particularly related to the operation of the hot air fan 28 in this embodiment. In the figure, one end of the hot air motor 29 is connected in parallel with one side of the power supply circuit 72, and the AC voltage from the power supply circuit 72 is applied to the hot air motor 29 in the next stage as an input voltage. The other end of the hot air motor 29 is connected to hot air motor driving means 64 , and the hot air motor driving means 64 is connected to the other side of the power supply circuit 72 .

The hot-air motor driving means 64 is composed of a third switch element 84 made of a triac, an IGBT element 85 and a resistor 86 for causing a current to flow through the LED element on the light emitting side of the third switch element 84. A phase control circuit 67 b of the heating control section 67 is connected to the hot air motor driving means 64 . The connections between the third switch element 84, the IGBT element 85, and the resistor 86 are the same as those of the hot-air heater driving means 62a described above, so the description thereof will be omitted.

The phase control circuit 67b receives a detection signal from the hot-air motor rotation detection means 55, and changes the ratio of the ON time for each cycle of the input voltage of the hot-air motor 29 so that the hot-air fan 28 rotates at a predetermined number of revolutions. A control signal is output to the IGBT element 85 to cause the hot-air motor driving means 64 to phase-control the hot-air motor 29 . The phase control circuit 67b in the first and second embodiments outputs a phase control signal to the IGBT element 85 so that the hot air fan 28 is maintained at a predetermined rotational speed during hot air convection heating.

The phase control circuit 67b of this embodiment incorporates a fluctuation data storage unit 81', and this fluctuation data storage unit 81' stores "fluctuation data" corresponding to the above-described fluctuation of the firewood flame. . This fluctuation data is read into the phase control circuit 67b and reflected in the phase control of the hot air motor 29. FIG.

The operation when the oven heating menu is selected in this embodiment will be described with reference to FIG. 13 . In FIG. 13, _T3 is a graph of the internal temperature of the microwave oven of this embodiment, and _Tp is a graph of the internal temperature of the conventional microwave oven whose temperature is controlled by the hot air heater 27 as a whole. Since the operation of converging and stabilizing the internal temperature of the microwave oven according to the present embodiment to the set temperature of 200° C. until the temperature reaches the saturated state is the same as that of the first embodiment, the explanation is omitted.

Upon receiving the detection signal from the internal temperature detection means 54, the cooking control unit 67 determines that the temperature change Diff of the internal temperature _T3 has reached a predetermined value of 8°C or less and is saturated at 200°C. Upon determination (place P ₃ ), a control signal is sent to send the fluctuation data stored in the fluctuation data storage unit 81' to the phase control circuit 67b. The phase control circuit 67b receives the fluctuation data, reads the fluctuation data, and controls the hot-air motor driving means 64 so that the rotation speed of the hot-air fan 28 is irregularly varied within a predetermined range, for example, 500 rpm to 2500 rpm. Send a signal. In this way, the number of revolutions of the phase-controlled hot air fan 28 is irregularly varied like "1/f fluctuation", and the fluctuation of the firewood flame is suppressed by intentionally not keeping the inside temperature _T3 constant. Since it is possible to reproduce and add an appropriate accent to the heating of the object S to be cooked, it is possible to appropriately change the finish of the object S to be cooked each time of cooking, and to add freshness to the taste and texture. can.

When the cooking control unit 67 receives a signal from the timer as the timing means of the control means 51 and determines that the oven heating has reached the finishing time _t2 (place _P4 ), it stops sending the fluctuation data. A control signal is sent to the fluctuation data storage unit 81'. As a result, the phase control circuit 67b sends a control signal to the hot-air motor driving means 64 so that the hot-air fan 28 is maintained at a predetermined rotational speed, thereby suppressing the temperature change Diff in the saturated state at 200°C. . Therefore, as in the second embodiment, the temperature change Diff of the internal chamber temperature _T3 can be stably reduced, and uneven browning of the food S to be cooked can be eliminated.

As described above, the hot air unit 24 as the oven heating means of the present embodiment includes the hot air fan 28 that feeds and circulates the heated air in the cooking chamber 14, and the hot air motor 29 that rotates the hot air fan 28 in a predetermined direction. and a hot-air motor driving means 64 for rotationally driving the hot-air motor, and the heat cooking control section 67 stores fluctuation data as a second storage means for storing fluctuation data in which "1/f fluctuation" is converted into data. The phase control circuit 67b of the heat cooking control unit 67 is provided with a storage unit 81', reads the fluctuation data from the fluctuation data storage unit 81', and changes the rotation speed of the hot air fan 28 irregularly within a predetermined range. A control signal is sent to the hot air motor driving means 64 .

In this case, the number of revolutions of the phase-controlled hot air fan 28 is varied irregularly like "1/f fluctuation", and the inside temperature _T3 is not kept constant to reproduce the fluctuation of the firewood flame. Since an appropriate accent can be added to the heating of the food S to be cooked, the finished food S can be moderately changed each time cooking is performed, and freshness can be added to the taste and texture.

The microwave oven of this embodiment further includes a timer as a timing means, and when the oven heating as cooking reaches the finishing time _t2 , the phase control circuit 67b detects the fluctuation from the fluctuation data storage unit 81'. Data reading is stopped and a control signal is sent to the hot-air motor driving means 64 so that the hot-air fan 28 is maintained at a predetermined rotational speed.

In this case, the temperature change Diff in the saturation state at 200°C is suppressed by suppressing the amount by which the inside temperature _T3 overshoots the set temperature of 200°C. Therefore, the temperature change Diff of the inside temperature _T3 can be stably reduced, and uneven browning of the food S to be cooked can be eliminated.

A fourth embodiment of an oven range as a cooking device according to the present invention will be described below with reference to FIG. In this embodiment, steam cooking is performed using mist superheated steam in the configuration of the microwave oven of the second embodiment.

In FIG. 14, _T4 is a graph of the internal temperature of the microwave oven of this embodiment, and _Tp is a graph of the internal temperature of the conventional microwave oven whose temperature is controlled by the hot air heater 27 as a whole. Since the control of the main heater 27a and the sub-heater 27b of the microwave oven of this embodiment is the same as that of the second embodiment, the explanation is omitted.

In this embodiment, when a menu of steamed dishes (steam cooking) using mist superheated steam is selected, the timer as the timing means of the control means 51 starts timing, and the heat cooking control section 67 detects the internal temperature detection means. Upon receiving the detection signal from 54, the main heater 27a and the sub-heater 27b are controlled as in the second embodiment. Further, when the heat cooking control section 67 receives the detection signal from the internal temperature detecting means 54 and determines that the internal temperature _T4 has reached the set temperature of 200° C., it sends a control signal to the pump driving means 65. Then, by controlling the operation of the water supply pump 47 incorporated in the mist supply device 43, water is ejected from the mist ejection holes 44 into the cooking chamber 14 to supply the mist. As a result, while the internal temperature _T4 varies irregularly, the amount of the temperature change Diff is suppressed and uniformed more than the amount of the temperature change Diff of the oven heating of the microwave oven of the second embodiment. The surface can be baked crisply while adding an appropriate accent to the heating of the food S. In addition, the mist is instantly vaporized into superheated steam, and the object to be cooked S in the cooking chamber 14 is heated with an appropriate amount of water molecules (superheated steam). .

At this time, in the heat cooking control section 67, the time from when the water is jetted into the cooking chamber 14 to when the water is jetted again is set, and the timer of the control means 51 counts the finishing time _t3 . The heating and cooking control section 67 repeats the above-described operation until it reaches. Note that the cooking control unit 67 may be configured so that the user can set the time until the water is jetted again.

When the heat cooking control unit 67 receives a signal from the timer as a timing means and determines that the steam cooking menu has reached the finishing time _t3 (place _P5 ), the fluctuation data is stopped to be sent. A control signal is sent to the data storage unit 81, and the PWM control circuit 67a sends a control signal to the hot air heater driving means 62a so as to perform PWM control as described in the first embodiment, and Suppress the temperature change Diff in the saturation state. At the same time, the heat cooking control section 67 stops sending the control signal to the pump drive means 65 and stops supplying the mist to the inside of the cooking chamber 14 . As a result, it is possible to stably reduce the temperature change Diff of the internal temperature _T4 , thereby eliminating uneven heating of the food S to be cooked, and at the same time, almost no water remains in the cooking chamber 14, so that most of the drain is discharged. can be drainless.

As described above, the microwave oven of this embodiment further includes the mist supply device 43 as mist supply means for ejecting water as a liquid into the cooking chamber 14 in the form of a mist. The water supply pump 43 of the mist supply device 43 is controlled so as to spout water when the temperature _T4 in 14 reaches the set temperature of 200°C.

In this case, the mist is instantly vaporized into superheated steam, and the object to be cooked S in the cooking chamber 14 is heated with an appropriate amount of water molecules (superheated steam) _. , the amount of the temperature change Diff is more suppressed and uniform than the oven heating of the microwave oven of the second embodiment, and the surface can be baked crisply while adding an appropriate accent to the heating of the object S to be cooked. .

The microwave oven of this embodiment further includes a timer as a timing means, and when the steam cooking as heat cooking reaches the finishing time _t3 (place _P3 ), the PWM control circuit 67a changes the fluctuation data storage unit Stop reading the fluctuation data from 81, send a control signal to the hot air heater driving means 62a to PWM-control the sub-heater 27b, and stop the supply of mist to the inside of the cooking chamber 14. , the transmission of the control signal to the pump driving means 65 is stopped.

In this case, the temperature change Diff of the inside temperature _T4 can be stably reduced to eliminate uneven heating of the food S to be cooked, and almost no water remains in the cooking chamber 14, so that most of the drain is discharged. can be drainless.

It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. For example, the first to fourth embodiments may be combined and implemented, and if the occurrence of voltage flicker due to the application and interruption of the input voltage can be suppressed, the power value of the main heater 27a is higher than the power value of the sub-heater 27b. may be less. Furthermore, the configuration and shape of each part of the first to fourth embodiments are not limited to those shown in the drawings, and can be changed as appropriate.

1 Microwave oven body (heating cooker)
14 cooking chamber 24 hot air unit (oven heating means)
27a main heater 27b sub-heater 28 hot air fan 29 hot air motor 43 mist supply device (mist supply means)
47 Water supply pump (mist supply means)
54 internal temperature detecting means 62 heater driving means (oven heating means)
62a hot air heater driving means 64 hot air motor driving means (oven heating means, hot air motor driving means)
67 cooking control unit 67a PWM control circuit (cooking control unit)
67b phase control circuit (cooking control unit)
81 Fluctuation data storage unit (first storage means)
81' fluctuation data storage unit (second storage means)
S Food to be cooked Th ₁ First threshold Th ₂ Second threshold

Claims (4)

a cooking chamber in which the food to be cooked is accommodated;
an oven heating means for heating the object to be cooked by hot air convection;
internal temperature detection means for detecting the temperature in the cooking chamber;
a heating and cooking control unit that controls the oven heating means so as to heat and cook the object to be cooked at a set temperature;
The oven heating means includes a main heater and a sub-heater for heating air, and a hot-air heater drive means for turning on and off the main heater and the sub-heater, wherein the power value of the main heater is higher than the power value of the sub-heater. is configured to be more
After the temperature in the cooking chamber reaches a first threshold value below the set temperature, when it is below a second threshold value that exceeds the set temperature by a predetermined temperature, the cooking control unit directs the main heater to sending a control signal to the hot air heater driving means so as to PWM-control the sub-heater while maintaining the energization of
When the temperature in the cooking chamber exceeds the second threshold, the cooking control section sends a control signal to the hot air heater driving means so as to turn off both the main heater and the sub-heater. A heating cooker characterized by: The heat cooking control unit comprises a first storage means for storing fluctuation data obtained by converting 1/f fluctuation into data,
3. The heating cooking control unit reads the fluctuation data from the storage unit and sends a control signal to the hot air heater driving unit so as to irregularly vary the energization rate of the PWM control. 1. The heating cooker according to 1. further comprising mist supply means for ejecting the liquid in the form of a mist into the cooking chamber;
3. The heating cooker according to claim 2, wherein the cooking control section controls the mist supply means so as to eject the liquid when the temperature in the cooking chamber reaches the set temperature. The oven heating means further includes a hot air fan for sending and circulating heated air into the cooking chamber, a hot air motor for rotating the hot air fan in a predetermined direction, and a hot air motor driving means for rotationally driving the hot air motor. prepared,
The heat cooking control unit comprises a second storage means for storing fluctuation data obtained by converting 1/f fluctuation into data,
The cooking control unit reads the fluctuation data from the storage means,
2. The heating cooker according to claim 1, wherein a control signal is sent to said hot-air motor driving means so that the rotation speed of said hot-air fan is varied irregularly within a predetermined range.

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