JP2010112590A - Heater heating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heater heating device capable of performing stable continuous cooking at high speed. <P>SOLUTION: A heating chamber 14 includes: a heating shelf 12 for placing a heating object 11 thereon; an upper heater 16 and a lower heater 17 that are heating sources; first to third temperature detecting means 18-20 for detecting temperature of the heating chamber 14. The heating chamber 14 further includes an exhaust port 21 for discharging the internal air, an exhaust fan 23, and a motor 24 for driving the fan. Each heater and the heating chamber are controlled respectively to have individually set temperatures by detecting the respective temperatures and controlling power supply to the heaters and the exhaust fan for exhausting the heating chamber. Therefore, a constant cooking condition can be regularly obtained. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for controlling the temperature of heating cooking in an electric heater heating cooking apparatus such as a microwave oven.

  In the prior art, the temperature control method in the oven chamber detects the time point when the sensor detection temperature rise due to the heater turning on, and then turns down with a time lag by turning off the heater, and after that time point, It is proposed that the heater is turned on again at least at a point earlier than the sensor detected temperature falls to the set value of the sensor detected temperature corresponding to the target value of the internal temperature.

In addition, the heater may be turned on immediately after the sensor detected temperature starts to decrease with a time lag, and the energized state of the heater when the sensor is turned on again is an intermittent on state that repeats on / off alternately. This is also proposed.
JP-A-5-137656

  However, in the conventional configuration, it is possible to raise and maintain the temperature in the oven chamber to a predetermined temperature, but it is the temperature of the heating source that determines whether the cooking is done in grill cooking, In the configuration, even the temperature of the heating source cannot be controlled, and stable continuous cooking cannot be realized.

  In order to solve the above-described conventional problems, an electric heater cooking apparatus according to the present invention includes a sensor for detecting the temperature in the oven, a sensor for detecting the heater temperature, and an exhaust fan for exhausting the air in the oven. The temperature of the exhaust fan and the output of the heater are controlled from the rise and fall of the temperature, and the temperature in the oven chamber and the temperature of the heater are raised and maintained at predetermined temperatures.

  With the above configuration, the temperature of the heat source related to cooking becomes constant, and a stable cooking result can be obtained every time during continuous cooking.

  A heater heating apparatus according to a first aspect of the present invention includes a heater serving as a heating source in a heating chamber, a heating chamber temperature sensor such as a thermistor or a thermocouple for detecting the temperature in the heating chamber, and the heater has a heater surface. A heater temperature sensor for detecting temperature is provided.

  The heating chamber has an exhaust port for exhausting the air in the heating chamber, and an exhaust fan and a motor for driving the exhaust fan are provided near the exhaust port or at the end of the ventilation path connected to the exhaust port. Prepare.

With the above structure, so that the temperature T _{H 0} of a predetermined heater is set to a temperature T _{O 0} of predetermined heating chamber which is set to detect the temperature T _O and the temperature T _H of the heater in the heating chamber, an exhaust By controlling the rotation of the fan and the input power of the heater, the temperature in the heating chamber and the temperature of the heater can be kept constant, and the amount of heat accumulated in the heating chamber and the radiant heat released from the heater are constant. Therefore, a stable cooking result can be obtained every time even if continuous cooking is performed.

According to a second aspect of the present invention, in the apparatus configuration according to the first aspect, when the detected temperature T _O of the heating chamber reaches a predetermined temperature T _O 0 of the set heating chamber, rotation of the exhaust fan is started, The room air is exhausted and the temperature in the heating chamber is lowered. Thereafter, when the second set predetermined temperature T _O 1 is reached, the rotation of the exhaust fan is stopped, so that the temperature in the heating chamber rises again. Thereby, the temperature T _{O in the} heating chamber can be kept constant within the set predetermined temperature range T _O 0 to T _O 1.

A third invention is a case where, in the apparatus configuration according to the first invention, the detected current temperature T _{O in} the heating chamber is lower than the predetermined temperature T _O 0 in which the temperature in the heating chamber is set. When the temperature change ΔT _O at a predetermined sampling time is not positive, that is, when the temperature T _{O in the} heating chamber does not rise to the predetermined temperature T _O 0, the rotational speed of the exhaust fan is set. To reduce the amount of air discharged in the heating chamber and promote the temperature rise in the heating chamber.

Further, when the detected current temperature T _{O in} the heating chamber is higher than the predetermined temperature T _O 0 in which the temperature in the heating chamber is set, the amount of change ΔT _{O in} temperature during a predetermined sampling time is When it is not negative, that is, when the temperature T _{O in the} heating chamber is not lowered to the set temperature T _O 0, the rotational speed of the exhaust fan is increased to increase the amount of air discharged in the heating chamber, Promotes temperature drop in the heating chamber. Thereby, the temperature in the heating chamber can be kept constant in the vicinity of the predetermined temperature T _O 0 that has been set.

In the fourth aspect of the invention, in the control of the exhaust fan according to the third aspect of the invention, even if the rotation of the exhaust fan is maximized, the temperature T _{O in the} heating chamber does not decrease to the predetermined temperature T _O 0 that has been set. In some cases, it is possible to prevent the temperature inside the heating chamber from rising excessively by lowering the heater temperature by giving priority to the heater temperature control or by stopping the heater output, thereby ensuring the safety of the device. Can do.

Also, when the rotation of the exhaust fan is stopped, the temperature T _{O in the} heating chamber is not increased to the predetermined temperature T _O 0 that has been set. it may indicate that the temperature of the room does not rise to a predetermined temperature T _{O 0.}

According to a fifth aspect of the present invention, in the apparatus configuration according to the first aspect of the invention, when the heater temperature reaches a predetermined temperature T _H 0, the heater is energized and stopped so as to suppress the temperature change of the heater. Switch to repeated intermittent energization. During intermittent energization, for a given temperature T _{H 0} temperature is set in the heater, even when the temperature T _H of the detected current is low, the average temperature variation [Delta] T _H at a predetermined sampling time If not positive, i.e., when in the state not rise to a predetermined temperature T _{H 0} of the temperature T _H of the heater is set, shorter stop time with respect to the energization time of the heater, raising the average temperature of the heater.

Also, for a given temperature T _{H 0} in which the temperature of the heater is set, even when a high current temperature T _H detected, when the change amount of the average temperature at the predetermined sampling time [Delta] T _H is not negative That is, when the heater temperature T _H is not lowered to the set temperature T _H 0, the stop time is lengthened with respect to the heater energization time, and the average temperature of the heater is lowered. Thus, the average temperature of the heater at a given time can be kept constant at a given temperature T _{O 0} neighborhood that has been set.

According to a sixth aspect of the present invention, in the apparatus configuration according to the first aspect, when the heater temperature reaches a predetermined temperature T _H 0, the input power is changed so as to suppress the change in the heater temperature. During the control of the input power, when the detected current temperature T _H is lower than the predetermined temperature T _H 0 at which the heater temperature is set, the average temperature at the predetermined sampling time is If the amount of change [Delta] T _H is not positive, by raising the input power to raise the temperature of the heater to increase the output of the heater.

Also, for a given temperature T _{H 0} in which the temperature of the heater is set, even when a high current temperature T _H detected, when the change amount of the average temperature at the predetermined sampling time [Delta] T _H is not negative By lowering the input power, the heater output is lowered to lower the heater temperature. Thereby, the average temperature of the heater can be kept constant in the vicinity of the set predetermined temperature T _O 0.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a cross-sectional view of a device viewed from the side, showing a basic configuration of a part that is a feature of the present invention.

  The present embodiment is a microwave oven using a heater as a heating source, and a heated object 11 such as food is provided on a heating shelf 12. An upper heater 16, a lower heater 17, and a heating chamber 14 that are heating sources are provided. The first temperature detecting means 18 for detecting the temperature of the upper heater 16, the second temperature detecting means 19 for detecting the temperature of the upper heater 16, and the third temperature detecting means 20 for detecting the temperature of the lower heater 17 are provided. The chamber 14 has an exhaust port 21 for discharging the internal air, and an exhaust fan 23 and a motor for driving the exhaust fan 23 in the vicinity of the exhaust port 21 or at a point where the ventilation path 22 is connected to the exhaust port 21. 24.

  Furthermore, the heating chamber 14 is provided with a door 30 for taking the heated object 11 in and out.

  In addition, either the upper heater 16 or the lower heater 17 may be omitted, and a plurality of heaters and temperature detection means may be added.

  About the microwave oven comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

FIG. 2 is a flowchart showing the operation of the first embodiment. First, simultaneously with the start of the operation, the control device 25 calculates the current temperature T _O of the heating chamber 14 detected from the first temperature detection means 18 and a predetermined temperature T _O 0 of the heating chamber 14 set in advance. The current temperature T _HU of the upper heater 16 detected from the second temperature detection means 19 and the predetermined temperature T _HU 0 of the upper heater 16 are detected by the current temperature of the lower heater 17 detected from the third temperature detection means 20. The temperature T _HL is compared with a predetermined temperature T _HL 0 of the lower heater 17.

Here, when the temperature T _O of the heating chamber 14 is higher than the predetermined temperature T _O 0, the exhaust fan 23 is rotated, and when the temperature T _O of the heating chamber 14 is lower than the predetermined temperature T _O 0, The exhaust fan 23 is stopped. When the temperature that is the condition for rotation and stop of the exhaust fan 23 is the same, the rotation and stop are frequently performed. Therefore, a preset rotation control temperature T _O1 of the exhaust fan 23 can be provided.

In the present embodiment, when the temperature T _O of the heating chamber 14 reaches the predetermined temperature T _O 0 (step S201), the exhaust fan 23 is rotated (step S202), and the temperature T _O of the heating chamber 14 is the predetermined temperature. When it falls below T _O 1 (step S203), the exhaust fan 23 is stopped (step S204).

On the other hand, when the temperature T _HU of the upper heater 16 is lower than the predetermined temperature T _HU 0 (step S211), energization of the upper heater 16 is started (step S212), and the temperature T of the upper heater 16 is increased.
_{When the HU} is higher than the predetermined temperature T _HU 0 (step S211), the energization to the upper heater 16 is stopped (step S214).

Here, even if the temperature T _O of the heating chamber 14 reaches a separately set heating chamber limit temperature T _O 2 (step S213), the energization to the upper heater 16 is stopped (step S214). In addition, regarding T _O 2, the same temperature as T _O 0 may be used. For the lower heater 17, the same control as that for the upper heater 16 is performed individually.

  As described above, in the present embodiment, the temperature of the heating chamber 14, the temperature of the upper heater 16 that is a heating source, and the temperature of the lower heater 17 are controlled independently, so that the object to be heated is Since the amount of heat transferred from the heating chamber and the radiant heat emitted from the heater are always constant, stable continuous cooking can be performed.

  Moreover, in this Embodiment, it can also be set as the structure which can vary rotation control of the exhaust fan 23 with the rotation speed using input electric power or a pulse motor.

  FIG. 3 is a graph showing the correlation between the temperature change in the heating chamber 14 and the rotational speed of the exhaust fan 23.

First, when energization of the heater is started, the temperature of the heating chamber 14 starts to rise. Here, when the rotation start temperature T _O 3 of the exhaust fan 23 set separately in advance is reached, the exhaust fan 23 starts to rotate (a). Thereby, the temperature rise is suppressed, the overshoot of the temperature control can be reduced, and there is an effect of exhausting the combustion gas generated when the temperature of the heating chamber 14 becomes a certain level or more.

Next, when the set target temperature T _O 0 is reached, the rotational speed of the exhaust fan 23 is increased to suppress the temperature rise of the heating chamber 14 (b). Thereafter, samples the temperature of the time determined arbitrarily, when not a negative value of the temperature change [Delta] T _O is defined arbitrarily, in order to try to further rise beyond the target temperature T _{O 0,} again, The rotational speed of the exhaust fan 23 is increased (c).

If the temperature of the heating chamber 14 falls, next, when the temperature falls below the rotation control temperature T _O 1, the number of revolutions is lowered (d). If the temperature change ΔT _O is not a predetermined positive value even at the rotation control temperature T _O 1 or lower, the rotational speed is lowered again (e).

Regarding the rotational speed of the increase and decrease value, it can be arbitrarily determined, usually a function of the temperature change [Delta] T _O. For example, when ΔT _O must be positive and greatly negative, the rotational speed is in an inversely proportional relationship that greatly decreases. Thereby, even if the set temperature of the heater that is a heating source changes, the temperature of the heating chamber can be stably adjusted.

  Further, in the present embodiment, the heater input control may be configured using a semiconductor power controller such as a triac.

  FIG. 4 is a graph showing the correlation between the temperature change of the heater and the input power.

First, 100% input power is applied at the initial stage of energization of the heater. This is because the temperature is quickly raised to the target temperature T _H 0. Here, when the temperature reaches a preset control temperature T _H 1 (a), the input power is reduced (for example, 75% power). Thereby, a temperature rise is suppressed and the overshoot of temperature control can be reduced.

Next, when the set target temperature T _O 0 is reached, the power supply to the heater is stopped (b). At this time, the input power (for example, 25% power) that has been greatly powered down may be continuously applied to moderate the temperature drop (marked with a star). When the temperature falls to the control temperature T _H 1, the input power reduced to 75% is applied again.

  Regarding the control of the input power described above, the increase / decrease in the power may be determined from the amount of change in temperature as in the control of the exhaust fan 23. Thereby, stable control with a small amount of temperature change can always be performed.

  In addition, when a large amount of noise is generated when power control is performed by the semiconductor power controller, it can be replaced with intermittent control that repeatedly turns on and off in a macro time. Thereby, it is possible to obtain a stable temperature condition as compared with energization and stop control.

  As described above, since the heater heating device according to the present invention can always maintain a stable heating state by precise temperature control, high-speed and stable continuous cooking can be realized, and an oven microwave oven, It can be applied to electric ovens, especially various types of commercial ovens.

Sectional drawing seen from the side of the heater heating device in embodiment of this invention Basic flowchart in the embodiment of the present invention Correlation diagram of heating chamber temperature and exhaust fan speed in exhaust fan control Correlation diagram of heater temperature and input power in heater output control

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 Heated object 12 Heating shelf 14 Heating chamber 16 Upper heater 17 Lower heater 18 First temperature detection means 19 Second temperature detection means 20 Third temperature detection means 21 Exhaust port 22 Ventilation path 23 Exhaust fan 24 Motor 25 Control Equipment 30 Oven door

Claims (6)

A heating chamber for storing an object to be heated, a heater for heating the heating chamber, an exhaust port for exhausting air in the heating chamber in the heating chamber, and driving an exhaust fan and the exhaust fan near the exhaust port A first temperature detecting means for detecting the temperature in the heating chamber, and a second temperature detecting means for detecting the temperature of the heater, and the rotation of the exhaust fan and the heater from the temperature in the heating chamber and the heater temperature. A heater heating device that controls output. Control of the rotation of the exhaust fan starts rotating and the temperature of the heating chamber reaches a predetermined temperature T _{O 0} that has been set, once it has cooled down to a temperature T _{O 1} a constant of a predetermined in the predetermined temperature T _{O 0} The heater heating apparatus according to claim 1, wherein control is performed to stop rotation. The rotation of the exhaust fan is controlled when the current temperature T _O is lower than the predetermined temperature T _O 0 in which the temperature in the heating chamber is set and the temperature change ΔT _O is not positive. If the current temperature T _O is higher than the predetermined temperature T _O 0 in which the temperature in the heating chamber is set, and if the temperature change ΔT _O is not negative, the rotational speed is increased. The heater heating apparatus according to claim 1. Control of rotation of the exhaust fan, and when the current temperature T _O is high, is positive variation [Delta] T _O of the temperature further, when the rotational speed is the largest, even more temperature control of the heater priority 4. The exhaust fan rotation control method according to claim 3, wherein the output of the heater is lowered or stopped. When the heater temperature reaches a predetermined temperature T _H 0 that is set, the heater temperature is switched to intermittent energization that repeats energization and stoppage. During the intermittent energization, the heater temperature is set to a predetermined temperature. against T H _0, and if the current temperature T _H is lower, if the change amount [Delta] T _H of the temperature is positive, the interruption time is short, the predetermined temperature T _{H 0} temperature is set in the heater against it, and in case the current temperature T _H is high, if not negative variation [Delta] T _H of the temperature, a heater heating apparatus according to claim 1, characterized in that to increase the disconnection time. The control of the temperature of the heater reaches a predetermined temperature T _{H 0} the temperature of the heater is set, switched to the input power control, the in input power control, the predetermined temperature at which the temperature of the heater is set T _H 0 respect, and in case the current temperature T _H is lower, if the change amount [Delta] T _H of the temperature is positive, increases the input power, for a given temperature T _{H 0} the temperature of the heater is set, and if the current temperature T _H is high, if not negative variation [Delta] T _H of the temperature, a heater heating apparatus according to claim 1, characterized in that lowering the input power.

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