JP2009287832A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the thermal storage efficiency of a thermal storage body in a preheating process, and to improve the heating efficiency in a subsequent cooking process. <P>SOLUTION: The cooking process (step S5 to step S11) of supplying hot blast generated by a fan and a heater into a galley and heating a cooking object while keeping the galley at a set cooking temperature based on a temperature sensor is performed, and a preheating process (step S1 to step S4) of preheating the galley with the fan and heater are performed before the execution of the cooking process. The rotation speed (step S6) of the fan in the preheating process is made lower than that of the fan in the cooking process (step S2). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cooking device that includes a heat storage body in a cooking chamber and performs a preheating process and a cooking process.

In a heating cooker, a heat accumulator is provided in a cooking chamber so that heating efficiency is improved during oven cooking (for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-118158

  In the prior art, there was a problem that the thermal efficiency during cooking did not increase so much despite the use of the heat storage body. In particular, when the cooking chamber is preheated in the preheating process, and then the food to be cooked is put in the cooking room and cooked in the cooking process, the heat storage efficiency of the heat storage body in the preheating process is low, and the subsequent cooking process There was a problem that the heating efficiency was not effectively improved.

  That is, the heating cooker configured to perform the preheating process and the cooking process executed subsequently thereto includes a fan and a heater for supplying hot air into the cooking chamber, and further detects the temperature of the cooking chamber. A cooking process comprising a temperature sensor, supplying hot air generated by the fan and the heater into the cooking chamber, and maintaining the cooking chamber at a set cooking temperature based on the temperature sensor to cook the food to be cooked; Before the cooking process is performed, a preheating process is performed in which the cooking chamber is preheated by the fan and the heater.

  In this product, the fan and the heater are energized in the same energization mode in both the preheating process and the cooking process, and when the set temperature is reached in the preheating process, the cooking chamber door is opened to accommodate food. In the cooking process after the door is closed, the heater is cut off to maintain the set temperature based on the temperature detected by the temperature sensor. In the preheating process, heat is stored in the heat storage body, but when the temperature sensor detects a set temperature (at the end of the preheating process), the heat storage amount of the heat storage body is not so large, and the cooking chamber door is opened. When the hot air in the cooking chamber flows out, there is a problem that the temperature rise in the cooking process is not accelerated quickly with a small amount of heat stored in the heat storage body.

  This invention is made | formed in view of the above-mentioned situation, The objective is to raise the heat storage efficiency of the heat storage body in a preheating process, and the heating cooker which can aim at the heating efficiency improvement in a subsequent cooking process. It is to provide.

  The present invention has been made paying attention to the following points. That is, conventionally, in both the preheating process and the cooking process, in addition to energizing the heater, the fan is rotated at a high speed, but although the rise of the air temperature in the cooking chamber is fast, the heat storage amount of the heat storage body is high. The fact is that it is not as much as expected. The reason is that the heat conductivity of the heat storage body is lower than the heat conductivity of the air, so the temperature of the air in the cooking chamber rises first, and the increase in the heat storage amount of the heat storage body is slow, and the temperature sensor is set. When the temperature was detected (when the preheating process was completed), the heat storage amount of the heat storage body was still small.

  The invention of claim 1 which pays attention to the above-mentioned points includes a heat storage body in the cooking chamber, a fan and a heater for supplying hot air into the cooking chamber, and a temperature sensor for detecting the temperature of the cooking chamber. A cooking process for supplying hot air generated by the fan and the heater into a cooking chamber, maintaining the cooking chamber at a set cooking temperature based on the temperature sensor, and cooking the food to be cooked; and Before execution, in the preheating process for preheating the cooking chamber with the fan and heater, the rotational speed of the fan in the preheating process is lower than the rotational speed of the fan in the cooking process. Has characteristics.

  In the first aspect of the invention, the rotational speed of the fan in the preheating process is set lower than the rotational speed of the fan in the cooking process, so that the circulation amount of hot air is reduced and the heat of the heater is transmitted to the air. As a result, heat transfer to the heat storage body is promoted, and the amount of heat stored in the heat storage body at the end of the preheating process is increased. Therefore, the heating efficiency in the subsequent cooking process is improved.

  ADVANTAGE OF THE INVENTION According to this invention, the thermal storage efficiency of the thermal storage body in a preheating process can be made high, and the heating efficiency improvement in a subsequent cooking process can be aimed at.

Hereinafter, a first embodiment (first embodiment) of the present invention will be described with reference to FIGS.
First, FIG. 2 shows the whole cooking device in a longitudinal section, and FIG. 3 shows the whole cooking device in a cross section. In FIG. 1 and FIG. 2, the cabinet 1 is formed of an outer box 2 and an inner box 3. The inside of the inner box 3 constitutes a cooking chamber 4. The inner box 3 is formed of a metal plate such as a steel plate. Therefore, the cooking chamber 4 is also surrounded by a metal plate.

The cooking chamber 4 has an open front surface (the left surface in FIGS. 2 and 3), and the opening is opened and closed by a door 6 having a handle 5. A shelf 7 is detachably disposed in the cooking chamber 4, and an object to be cooked (not shown) is placed on the shelf 7 and accommodated in the cooking chamber 4.
There are a plurality of shelf boards 7 (two in the illustrated example), and the shelf receivers 7 a provided on the left and right side walls of the cooking chamber 4 are arranged substantially horizontally with different levels above and below the cooking chamber 4. It has become.

  In this case, which is one side wall of the cooking chamber 4, a plurality of ventilation portions 8a to 8f are formed on the rear side wall 4a. Each of the ventilation portions 8a to 8f is formed of a large number of small holes such as a number of punching holes, for example, and the outside of the cooking chamber 4 (this is the boundary of the rear side wall 4a of the cooking chamber 4 having the ventilation portions 8a to 8f). In this case, a hot air generation chamber 9 is formed on the rear side. Specifically, the hot air generation chamber 9 is formed by mounting a casing 10 and a heat shield cover 11 having a size covering the whole of the ventilation portions 8 a to 8 f on the back surface of the rear side wall 4 a of the cooking chamber 4. A heater 12 and a fan 13 are disposed in the hot air generating chamber 9 as heat sources.

  The heater 12 is positioned around the hot air generating chamber 9, and the heater 12 is close to the rear side wall 4 a of the cooking chamber 4. On the other hand, the fan 13 is positioned at the center of the hot air generating chamber 9 and is driven to rotate by a fan motor 14 disposed outside the hot air generating chamber 9.

  With this configuration, when the heater 12 and the fan motor 14 are energized, the heater 12 generates heat and the fan motor 14 drives the fan 13 to rotate. Thereby, as indicated by an arrow A in FIG. 2, the fan 13 sucks the air in the cooking chamber 4 from the ventilation portion 8 a at the center of the rear side wall 4 a of the cooking chamber 4 into the hot air generation chamber 9 and sends it out. The air sent to the surroundings is heated by contacting with the heater 12 to be turned into hot air and blown out from the ventilation portions 8b to 8f around the rear side wall 4a of the cooking chamber 4 to the cooking chamber 4.

  And it is repeated that the hot air which blows off to the cooking chamber 4 and goes around the cooking chamber 4 is sucked by the fan 13 from the ventilation part 8a of the center part of the rear side wall 4a of the cooking chamber 4 to the hot air generation chamber 9. Thus, hot air is generated, and the hot air is circulated between the cooking chamber 4 and the cooking chamber 4 through the ventilation portion 8 of the rear side wall 4a which is a boundary side wall with the hot air generation chamber 9 of the cooking chamber 4. Therefore, the heater 12 and the fan 13 in the hot air generation chamber 9 function as a hot air supply device 15 that generates and circulates the hot air.

  On the cooking chamber 4 side of the rear side wall 4a of the cooking chamber 4, a heat storage body 16 is disposed in the vicinity of the rear side wall 4a. The heat storage body 16 is made of, for example, a ceramic plate. FIG. 3 is a front view of the cooking chamber 4 with the shelf 7 removed, and FIG. 4 is a front view of the cooking chamber 4 with the shelf 7 set. As shown, substantially all of the rear side wall 4a of the cooking chamber 4 is covered, except that the portions corresponding to the ventilation portions 8a to 8f are provided with ventilation openings 17a to 17f. Therefore, the hot air blown out from the hot air generating chamber 9 is blown into the cooking chamber 4 through the vents 17b to 17f, and the hot air sucked from the cooking chamber 4 is sucked into the hot air generating chamber 9 through the vent 17a.

3 and 4, the heater 12 in the hot air generation chamber 9 is indicated by a broken line, and the heater 12 has a rectangular frame shape.
FIG. 5 shows an electrical configuration for heating using the heater 12 and the fan 13. The control device 19 includes a CPU, a ROM, a RAM, and the like, and serves as a control means. In the preheating process and the cooking process, the heater 12 and the fan 13 (fan motor 14) are controlled according to a predetermined program. The control device 19 is supplied with input signals from the switch group 20 and the temperature sensor 21.

  The switch group 20 is provided on an operation panel (not shown), a cooking menu switch, a time setting switch for setting a cooking time, a cooking start switch, a temperature setting switch for setting a cooking temperature, and the presence / absence of preheating. Preheat setting switch to set.

As shown in FIGS. 4 and 5, the temperature sensor 21 is attached to the ceiling portion of the cooking chamber 4 and detects the temperature (air temperature) of the cooking chamber 4.
The control device 19 controls the heater 12 via a heater drive circuit 22 and controls the fan motor 14 via a motor drive circuit 23.

The heater drive circuit 22 can fully energize (continuously energize) the heater 12 as it is, and can also energize it by controlling the phase (phase control energization), and adjust the phase control angle. (Phase adjustment) is also possible. This phase control waveform is shown in FIG.
The motor drive circuit 23 can change the rotational speed of the fan motor 14 by adjusting the motor applied voltage. The heater drive circuit 22 and the motor drive circuit 23 are supplied with 100V commercial AC power.

  The control device 19 also controls the display 24 and the buzzer 25. The display 24 is provided on an operation panel (not shown), and displays a set time, set temperature, and the like. The buzzer 25 is provided on a panel (not shown), and is used for preheating stroke end notification and cooking stroke end notification.

  FIG. 1 shows the control contents of the control device 19, particularly the control contents when cooking using the heater 12 and the fan 13 such as oven cooking is selected. Further, FIG. 7 shows a time chart of the operation state of each device and the change state of the temperature detected by the temperature sensor 21 when the preheating process and the cooking process are continuously performed.

  In step S1, it is determined whether or not there is a preheating stroke (whether or not it is selected). This preheating process may be pre-installed in the cooking menu or may not be pre-installed. In some cases, the user may select preheating by manual operation.

  If it is determined that there is a preheating process, in step S2, the rotational speed of the fan 13 and hence the rotational speed of the fan motor 14 are lowered to drive the fan motor 14 and the heater 12 is energized as it is (continuous energization). . The control device 19 controls the motor drive circuit 23 so as to set the motor drive voltage to 60 V, thereby setting the fan motor 14 rotation speed (fan rotation speed) to 800 rpm (which will be apparent from the following description, but the fan during the cooking process). Lower than the number of revolutions).

Hot air is generated by energization of the heater 12 and the fan motor 14, and circulates between the cooking chamber 4 and the hot air generation chamber 9 as described above. In this case, the circulation amount of the hot air is not large, the heat transfer to the air (circulated air) in the cooking chamber 4 is somewhat suppressed, and the heat transfer to the heat storage body 16 is promoted.
In step S3, it is determined whether or not the temperature detected by the temperature sensor 21 has reached a preset preheating temperature (in this case, the same setting as the cooking temperature). In S4, the buzzer 25 is caused to output a notification sound for notification of the end of the preheating stroke. At the end of the preheating process, the heat storage body 16 has sufficiently stored heat.

Thereafter, the user hears this notification sound, opens the door 6, accommodates the food to be cooked, closes the door 6, and operates the start switch.
If it is determined that the start switch has been operated (step S5), the process proceeds to step S6, where the rotational speed of the fan 13 is set high (for example, the motor drive voltage is set to 100V to 1800 rpm). And the heater 12 is energized by phase control. In this case, since the heat storage body 16 has sufficiently stored heat, sufficient heat release from the heat storage body 16 can be expected, and a favorable temperature rise can be expected. And the heat transfer (heating) effect to a foodstuff is improved by making fan rotation speed high.
In step S7 and step S8, the temperature is controlled so that the temperature detected by the temperature sensor 21 becomes the set cooking temperature. That is, the control angle adjustment of the heater phase control is performed so that the detected temperature becomes the set cooking temperature (when the detected temperature is greater than the set cooking temperature, the control angle is decreased, and when it is reversed, the control angle is increased).

When it is determined that the cooking time set in step S9 has elapsed, the fan motor 14 is stopped and the heater 12 is turned off in step S10, and the buzzer 25 is overheated in step S11. A notification sound for notification is output.
When it is determined in step S1 that there is no preheating stroke, the process proceeds to steps S12 to S17. In step S12, the fan 13 is driven at a high rotational speed (for example, 1800 rpm), and the heater 12 is energized continuously.

  In step S13 and step S14, the temperature is controlled so that the temperature detected by the temperature sensor 21 becomes the set cooking temperature. That is, the heater 12 is turned off so that the detected temperature becomes the set cooking temperature (the heater is turned on when the detected temperature is higher than the set cooking temperature, and the heater is turned off when the detected temperature is reversed).

  When it is determined that the cooking time set in step S15 has elapsed, the fan motor 14 is stopped and the heater 12 is turned off in step S16, and the heating process ends in the buzzer 25 in step S17. A notification sound for notification is output.

  According to the above-described embodiment, since the rotation speed of the fan 13 in the preheating process is lower than the rotation speed of the fan 13 in the cooking process, the circulation amount of the hot air is reduced and the heat of the heater is transmitted to the air. Is suppressed, heat transfer to the heat storage body 16 is promoted, and the amount of heat stored in the heat storage body 16 at the end of the preheating stroke is increased. Therefore, even if the door 6 is opened and closed for food storage and the internal hot air flows out after the preheating process is completed, the heat storage amount in the heat storage body 16 is sufficient, and the heating efficiency in the subsequent cooking process is improved. .

  Further, according to the present embodiment, the heater 12 is energized continuously in the preheating process, and the heater 12 is controlled in temperature by phase control in the cooking process. Heating can be performed satisfactorily without causing insufficient heating. By the way, when temperature control is performed by fully energizing the heater 12 (energizing the AC power supply as it is) and turning off the power, the temperature ripple (overshoot and undershoot with respect to the set cooking temperature) is extremely large. The heating finish may be unsatisfactory due to overheating due to the chute or underheating due to the undershoot. However, this embodiment can solve this problem.

  9 and 10 show a second embodiment of the present invention. In the second embodiment, in the preheating step, temperature control is performed to maintain the heater 12 at the preset preheat temperature for a preset extension time after reaching a preset preheat temperature. I have to.

  That is, Step Sa to Step Sd are different from the first embodiment. In step S1, it is determined that there is preheating. In step S2, the fan 13 is driven at a low speed, and the heater 12 is energized as it is (continuous energization). In step S3, the temperature detected by the temperature sensor 21 is detected. However, when it is determined that the preset preheating temperature has been reached, the heater 12 is switched to phase control energization in step Sa, and the phase control is adjusted so as to reach the preheating temperature (step Sb, step Sc). As a result, the preheating temperature is maintained, and if a preset extension time te has elapsed (determined in step Sd), a buzzer is notified in step S4, and the preheating process is terminated.

  In the second embodiment, since control for maintaining the preheating temperature for a predetermined time after reaching the preheating temperature is performed, the heat storage effect on the heat storage body 16 can be further expected. That is, the heat capacity of the air in the capacity of the cooking chamber 4 and the heat capacity of the spring 16 are higher in the heat storage body 16, and the heat conduction transmitted to the space in the volume of the cooking chamber 4 and the heat conduction transmitted to the heat storage body 16. Since the heat storage body 16 is slower than the speed, the heat storage body 16 has a capacity capable of storing heat even after the cooking chamber 4 reaches the set preheating temperature which is the target temperature. Therefore, heat can be further stored in the heat storage body 16 by maintaining preheating.

  11 and 12 show a third embodiment of the present invention. In this embodiment, the fan 13 is not driven during the preset initial preheating time from the start of the preheating process, and the heater 12 is continuously energized, and the fan 13 is driven after the set initial preheating time has elapsed. ing.

  That is, Step Se to Step Sg are different from the first embodiment. If it is determined in step S1 that preheating is present, the heater 12 is energized continuously for a preset initial preheating time ts (see FIG. 12), as shown in steps Se and Sf. During the set initial preheating time ts, the rotational speed of the fan 13 is set to zero (not driven). When the set initial preheating time ts elapses, the fan 13 is driven at a low rotation speed in step Sg, and when the set preheating temperature is reached (step S3), a buzzer is notified in step S4, and the preheating process is terminated.

  According to the third embodiment, by only heating the heater 12 at the beginning of preheating, the heat supply to the heat storage body 16 at the initial stage of the preheating process is promoted, and the heat storage effect on the heat storage body 16 is further expected. it can.

  In addition, this invention is not limited to said each Example, You may implement as changed as follows. In the embodiment, the phase of the heater 12 is controlled. However, this may be wave number control as shown in FIG. 13 shown as the fourth embodiment of the present invention. This wave number control is a control for turning off (cutting) an appropriate plus waveform portion or minus waveform portion of the AC power source, in which (a) shows a relatively high output state and (b) shows a low output state. ing. Even if it does in this way, the effect similar to the case of phase control can be acquired.

  Moreover, in the said Example, although the low rotation speed of the fan 13 was set to 800 rpm and the high rotation speed was set to 1800 rpm, the rotation speed should just be set suitably. Further, the set preheating temperature and the set cooking temperature may be different temperatures. Further, the heat storage body is not limited to ceramic, and various materials can be selected.

Flow chart of control contents showing the first embodiment of the present invention Vertical side view of cooking device Transverse plan view of a cooking device View of the cooking room with the shelf removed from the front A view of the cooking chamber with the shelf set from the front Electrical configuration block diagram Time chart showing the operating status of each device and changes in cooking room temperature Waveform diagram for explaining phase control FIG. 1 equivalent view showing a second embodiment of the present invention. 7 equivalent diagram FIG. 1 equivalent view showing a third embodiment of the present invention. 7 equivalent diagram Waveform diagram showing the fourth embodiment of the present invention

Explanation of symbols

  In the drawings, 4 is a cooking chamber, 9 is a hot air generating chamber, 12 is a heater, 13 is a fan, 14 is a fan motor, 15 is a hot air supply device, 16 is a heat storage body, 19 is a control device, and 21 is a temperature sensor.

Claims (4)

A heat storage body is provided in the cooking chamber, a fan and a heater for supplying hot air to the cooking chamber are provided, and a temperature sensor for detecting the temperature of the cooking chamber is further provided.
A cooking step of supplying hot air generated by the fan and the heater into a cooking chamber, and heating the cooking object while maintaining the cooking chamber at a preset cooking temperature based on the temperature sensor;
Before performing the cooking process, a preheating process for preheating the cooking chamber with the fan and heater is performed.
The cooking device according to claim 1, wherein the rotation speed of the fan in the preheating process is lower than the rotation speed of the fan in the cooking process.   2. The cooking device according to claim 1, wherein the heater is continuously energized in the preheating process, and the heater is subjected to temperature control by phase control or wave number control in the cooking process.   In the preheating step, temperature control is performed so that the heater is maintained at the preset preheat temperature for a preset extension time after reaching a preset preheat temperature. Item 3. A cooking device according to item 1 or 2.   The heater is continuously energized without driving the fan during a preset initial preheating time from the start of the preheating process, and the fan is driven after the initial preheating time has elapsed. Item 4. The cooking device according to any one of Items 1 to 3.

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