JP2014048012A - High frequency heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that there are prior art food drying methods such as a method for air seasoning under a room temperature irrespective of shade drying and sun-drying and a deliberate drying in an oven of low temperature of 100°C or less, such cooking method requiring continuous drying for several hours to several tens hour and several days on specific foods so that the cooking method is inconvenient for a user.SOLUTION: A heater heating step for performing a heating operation with a heater is carried out as a drying cooking mode after performing a high frequency wave heating step for heating with a high frequency oscillator 11.

Description

  The present invention relates to a high-frequency heating device that heats an object to be heated at high frequency.

  As a prior art, there has been a microwave oven that controls the driving of a heating element when drying an object to be dried and maintains the temperature in the cooking chamber at a lower drying temperature than that during oven heating (see, for example, Patent Document 1).

Japanese Utility Model Publication 1-26962

  Dried foods such as dried fruits and dried fish have been around for a long time. As its characteristics, it is known that it has a rich taste and can efficiently absorb nutrients in a small amount, and has good storage stability. It is one of the cooking and storage methods that has been attracting attention recently.

  As a method of drying food, there is a method of natural drying at room temperature equivalent regardless of whether it is shaded or sun-dried, or a method of slowly drying using a low-temperature oven of 100 ° C. or less. Depending on the ingredients, the cooking method must be kept dry for several days, and there is a problem that is not an easy cooking method for the user.

  On the other hand, since water evaporation is more likely to be performed at a higher temperature, for example, a method of heating at a temperature higher than 150 ° C., which is used for ordinary oven cooking, can be considered, but only the surface is excessively dried. However, there is a problem that the center part is finished with insufficient moisture, although it seems to be dry at first glance.

  The present invention has been made to solve the above-described problems, and provides a high-frequency heating apparatus that can dry a heated object in a short time while suppressing the burning of the heated object.

  The high-frequency heating device of the present invention includes a heating chamber that houses an object to be heated, a high-frequency oscillator that heats the object to be heated by supplying a high frequency into the heating chamber, and at least one surface of the wall surface of the heating chamber. A heater for heating the object to be heated and the heating chamber, setting input means for inputting at least an operation related to selection of a heating mode, and the high-frequency oscillator and the heater according to the selected heating mode Control means for controlling the heating operation of the heating means, and the control means has, as the heating mode, a dry cooking mode for performing cooking for drying the article to be heated, and heating by the high-frequency oscillator in the dry cooking mode. After performing the high frequency heating process which performs, the heater heating process which performs the heating by the said heater is implemented.

  In the dry cooking mode, the high-frequency heating device according to the present invention performs a heater heating step of heating by a heater after performing a high-frequency heating step of heating by a high-frequency oscillator. For this reason, a to-be-heated material can be dried in a short time, suppressing the burning etc. of a to-be-heated material.

It is a main body perspective view of the high frequency heating apparatus which shows Embodiment 1 of this invention. It is a front sectional view of the center of the heating chamber of the high-frequency heating device showing Embodiment 1 of the present invention. It is a sectional side view of the center of the heating chamber of the high-frequency heating device showing Embodiment 1 of the present invention. It is sectional drawing of the tray of the high frequency heating apparatus which shows Embodiment 1 of this invention. It is a control block diagram of the high-frequency heating device showing Embodiment 1 of the present invention. It is a flowchart of the high frequency heating apparatus which shows Embodiment 1 of this invention. It is a flowchart of the high frequency heating apparatus which shows Embodiment 1 of this invention. It is a graph of the weight after drying of the to-be-heated material dried with the high frequency heating apparatus which shows Embodiment 1 of this invention.

Embodiment 1 FIG.
FIG. 1 is a perspective view of a main body of a high-frequency heating device showing Embodiment 1 of the present invention.
In FIG. 1, a main body 1 of a high-frequency heating device is provided with a heating chamber 2 in which an object to be heated 21 is accommodated, and a door 3 is opened so that the object to be heated 21 (not shown in FIG. 1) is placed. After the installation, the door 3 is closed, and the cooking is performed by inputting and operating the setting on the operation panel 5.
The control means 31 (described later) controls the heating operation using a signal from the operation panel 5, for example, a cooking mode selection operation or an operation button ON as a trigger. In addition, an operation state and a setting state are displayed on a display device configured by a liquid crystal or the like installed in the operation panel 5. If you want to stop cooking manually or restart the installation, pressing the cancel key installed on the operation panel 5 will send a signal to the controller to stop the operation. Stop supplying power to the heat source.

  Reference numeral 25 denotes door opening / closing detection means. The door open / close detection means 25 detects the open / closed state of the door 3. For example, a protrusion provided on the door 3 side detects opening / closing by pressing a micro switch (not shown) as a detection device. The door 3 is provided with a viewing window 4 that allows the inside of the heating chamber 2 to be viewed.

  Reference numeral 6 denotes a bottom ceramic plate. The bottom ceramic plate 6 is configured as a bottom plate (bottom surface) of the heating chamber 2. The object to be heated 21 may be placed directly on the bottom ceramic plate 6 and heated, or the object to be heated 21 may be placed on the tray 20 described later and heated. The tray 20 is installed in such a manner that both side surfaces are placed on a rail 7 provided on the inner side surface of the heating chamber 2.

FIG. 2 is a front sectional view of the center of the heating chamber of the high-frequency heating device showing Embodiment 1 of the present invention.
FIG. 3 is a side sectional view of the center of the heating chamber of the high-frequency heating device showing the first embodiment of the present invention.
As shown in FIGS. 2 and 3, the high-frequency heating device according to the first embodiment has a top heater 8, a bottom heater 9, and a convection unit as heat sources for heating an object to be heated 21 placed in the heating chamber 2. 10. A high-frequency oscillator 11 is installed, and these heat sources are used depending on the purpose of heating.
The top heater 8 is composed of a flat heater in which heating wires are sandwiched between insulating members such as mica. The top heater 8 is installed so as to be in close contact with substantially the entire top surface of the heating chamber 2. By heating the entire top surface of the heating chamber 2, the heated object 21 is uniformly distributed mainly by secondary radiation. It is possible to heat. 8a is a heat insulating material. The heat insulating material 8a does not let the heat emitted from the top heater 8 escape to the outside of the casing, and contributes to improving the heating efficiency to the heating chamber 2 and reducing the temperature outside the casing. The heat insulating material 8a can be composed of glass wool, rock wool, vacuum heat insulating material, or the like.

  The bottom heater 9 is located under the bottom ceramic plate 6 and is in a position that is not touched by the user and has a safe configuration. The bottom heater 9 is composed of, for example, a sheathed heater or a glass tube heater, and heats the object to be heated 21 by secondary radiation as with the top heater 8.

The convection unit 10 heats by circulating hot air inside the heating chamber 2 (hot air convection heating). Reference numeral 10a denotes a convection heater, which includes a sheathed heater and a glass tube heater. Reference numeral 10b denotes a convection fan, which is provided with a rotational driving force by a fan motor (not shown) installed on the back surface and allows ventilation. A punching hole 10c is provided at a position facing the center and the outer peripheral side of the convection fan 10b. The convection unit 10 is a casing having a closed back surface, and is configured to communicate with the heating chamber 2 only by the punching hole 10c on the heating chamber 2 side. When the convection fan 10b rotates, the convection unit 10 repeatedly sucks air into the convection unit 10 from the central punching hole 10c and discharges it into the punching hole 10c at the outer peripheral portion, thereby repeating the convection heater 10a and the top heater 8. The heated object 21 in the heating chamber 2 is heated while increasing the temperature while exchanging heat with the top surface heated by the bottom surface and the bottom surface heated by the bottom surface heater 9.
The hot air and hot air provided by the convection unit 10 perform effective heating on the object 21 to be heated using convection heat transfer by the heated air, and quickly remove water evaporated from the surface of the object 21 to be heated. It has the effect of eliminating and excellent drying effect.

The top heater 8, the bottom heater 9, and the convection unit 10 correspond to the “heater” in the present invention.
In the present embodiment, the case where the top heater 8, the bottom heater 9, and the convection unit 10 are provided as the heater of the present invention will be described. However, the present invention is not limited to this, and among these, At least one of the above may be provided.

The high-frequency oscillator 11 is configured by a magnetron that oscillates a microwave of 2.45 GHz, for example. The microwave emitted from the high-frequency oscillator 11 propagates in the waveguide 12 and is connected to the bottom surface side of the heating chamber 2 through the rotating antenna 13 by coaxial coupling, and efficiently transmits the microwave to the heating chamber 2. It is possible to make it.
The rotating antenna 13 is given a rotational driving force by the antenna motor 14 and can change the microwave distribution state in the heating chamber 2 while oscillating microwaves, thereby heating the object to be heated 21 evenly. It becomes.
The dielectric heating by the microwave mainly has a characteristic of selectively heating the moisture in the object to be heated 21, and can heat the object to be heated 21 as compared with radiation heating or convection heating.

Reference numeral 15 denotes a cooling fan. The cooling fan 15 is a ventilation device that takes in air outside the main body 1 into the housing, and is constituted by a DC fan. The role of the cooling fan 15 is to cool the electrical components such as the high-frequency oscillator 11 that generates heat by high-frequency oscillation and the power supply board (not shown) that tends to become high temperature, but in this embodiment, the heating chamber 2 By introducing cooling air into the interior, it is of great significance to exhaust the heat and steam trapped in the heating chamber 2 out of the heating chamber 2.
Reference numeral 17 denotes a cooling air introduction hole. The cooling air introduction hole 17 is composed of a sufficiently fine mesh or punching hole so that high frequency does not leak, and introduces the cooling air from the cooling fan 15 into the heating chamber 2. A cooling air exhaust hole 18 that discharges the cooling air guided into the heating chamber 2 to the outside of the heating chamber 2 is formed in the upper back of the heating chamber 2. In addition, an exhaust duct 19 that discharges the exhaust from the cooling air exhaust hole 18 to the outside of the main body 1 is provided.
The cooling air introduction hole 17 corresponds to the “air path” in the present invention. The cooling air exhaust hole 18 corresponds to the “exhaust port” in the present invention.

With such a configuration, as indicated by arrows in FIGS. 2 and 3, the cooling air 16 taken into the housing by the cooling fan 15 cools the periphery of the high-frequency oscillator 11 and the electrical components, and then introduces the cooling air. It is introduced into the heating chamber 2 from the hole 17 (solid line arrow in FIG. 3). Then, the cooling air introduced from the cooling air introduction hole 17 is discharged to the cooling air exhaust hole 18 at the upper back of the heating chamber 2 through the central portion of the heating chamber 2 where the article to be heated 21 is installed. It is discharged out of the housing via the duct 19 (dotted line arrow in FIG. 3).
Therefore, the driving of the cooling fan 15 has an effect of promoting the drying in the dry cooking mode, in particular, the moisture evaporated from the heated object 21 is discharged outside the heating chamber 2 without staying in the heating chamber 2. Even if the temperature of the electrical components such as the high-frequency oscillator 11 is low enough not to be cooled, the situation of the high-frequency oscillator 11 is determined when it is determined from the result of the steam detection means 22 described later that steam is present. Separately, it is determined whether the drive is ON or OFF. Details will be described later.

  In the present embodiment, a configuration in which the cooling air after cooling the electrical components such as the high-frequency oscillator 11 is introduced into the heating chamber 2 will be described, but the present invention is not limited to this. For example, the cooling air introduced into the housing may be divided into a flow for cooling the high-frequency oscillator 11 and the like and a flow introduced into the heating chamber 2. Further, the positions of the cooling air introduction hole 17 and the cooling air exhaust hole 18 are not particularly limited. Further, the cooling fan 15 is not limited to the ON-OFF control, and for example, the air volume may be changed as fan rotation speed control.

  20 is a tray. The tray 20 is installed in the heating chamber 2, and an object to be heated 21 is placed on the upper surface thereof. Details of the tray 20 will be described with reference to FIG.

FIG. 4 is a cross-sectional view of the tray of the high-frequency heating device showing Embodiment 1 of the present invention.
The tray 20 has a shape having an open portion 20a such as a strip hole on the installation surface (at least the placement region) of the object to be heated 21 as shown in FIG. 4 (A), or is heated as shown in FIG. 4 (B). It is set as the shape which attaches the convex part 20b (unevenness | corrugation) to the installation surface (at least mounting area | region) of the thing 21. FIG. By setting it as such a shape, the hot air produced | generated by the convection unit 10, the cooling air 16, etc. will contact also the bottom face of the to-be-heated material 21, and there exists an effect which accelerates | stimulates drying. Note that the tray 20 may be formed in a net shape.
The tray 20 is made of a silicon elastomer, and a high frequency heating element that generates heat when irradiated with a high frequency, such as dielectric powder such as ferrite powder or magnetic powder, is mixed in the molding. Therefore, it has a function of self-heating when irradiated with microwaves. According to this configuration, the object to be heated 21 is heated both internally and externally by both self-heating by microwaves and heat transfer from the tray 20 as the installation surface, and drying is promoted.

2 and 3 again, reference numeral 22 denotes a vapor detection means. The steam detection means 22 is composed of a thermistor or the like, and is disposed in the vicinity of the cooling air exhaust hole 18. The steam detection means 22 detects the presence or absence of steam in the heating chamber 2 by detecting the temperature of the air discharged from the cooling air exhaust hole 18. As a detection method, it is possible to detect by using at least one of temperature fluctuation and temperature gradient caused by steam on the thermistor, or temperature fluctuation and temperature gradient caused by condensation on the thermistor surface. Is possible. Further, since the steam temperature in the atmospheric pressure is approximately 100 ° C., it is possible to determine that steam is generated when a temperature within a predetermined range is detected based on this temperature. Note that the method of steam detection is not limited to this, and detection can be performed by any method.
In addition, the vapor | steam detection means 22 can be utilized also as an atmospheric temperature detection means which detects the atmospheric temperature in the heating chamber 2 by comprising the vapor | steam detection means 22 with a thermistor.

Reference numeral 23 denotes a non-contact temperature detecting means. The non-contact temperature detecting means 23 can measure the temperature in a non-contact manner by detecting the amount of infrared rays and the wavelength of the heated object 21 placed in the heating chamber 2.
When the temperature of the object to be heated 21 detected by the non-contact temperature detecting means 23 exceeds 100 ° C., the moisture on the surface of the object to be heated 21 evaporates, so that the latent heat of vaporization becomes unnecessary, that is, a dry state. There is an effect that can be grasped. Further, if the heating is maintained as it is, the temperature may continue to rise above 100 ° C., which may cause problems such as scorching, but the surface temperature of the article to be heated 21 is detected by the non-contact temperature detecting means 23 to 100 ° C. If it is stopped or the output is suppressed below, it can be prevented in advance.

Reference numeral 24 denotes a high frequency oscillator temperature detecting means. The high frequency oscillator temperature detecting means 24 is composed of a thermistor or the like, and is disposed in contact with the high frequency oscillator 11 to detect the temperature of the high frequency oscillator 11 itself.
When the object to be heated 21 placed in the heating chamber 2 has an extremely light heat load, or the object to be heated 21 is not placed in the heating chamber 2, or there is no target that absorbs high frequency or is small The high frequency oscillated by the high frequency oscillator 11 increases the amount returned to the high frequency oscillator 11 itself and self-heats, which may cause a failure. Therefore, it is necessary to use the high-frequency oscillator 11 at as low a temperature as possible, and it is important to cool it with the cooling air 16. On the other hand, the state in which the high-frequency oscillator 11 is heated means that the object to be heated 21 is a light heat load for high-frequency dielectric heating, that is, a load with little moisture, and the detected temperature of the high-frequency oscillator temperature detecting means 24 is It can also be used as an indication of how the heated product 21 is dried.

Next, the control block will be described.
FIG. 5 is a control block diagram of the high-frequency heating device showing the first embodiment of the present invention.
The power supply to the control means 31 and the power supply device 33 is controlled by the main board 32 that controls on and off of the power supply to the main body 1.
The power supply device 33 is connected to the antenna motor 14, the inverter (INV) substrate 37, the high frequency oscillator 11 (magnetron), the top heater 8, the bottom heater 9, and the convection unit 10 via a relay 36. The control means 31 controls the relay 36 on the operation panel 5 according to the setting / input information input by the input means 5a to control whether or not to supply power to each heat source.

The control unit 31 acquires temperature information from the vapor detection unit 22 (atmosphere temperature detection unit), the non-contact temperature detection unit 23, and the high frequency oscillator temperature detection unit 24, and the relay 36 is turned on and off based on each temperature. To control the operation of the heat source. Details will be described later.
The operation panel 5 corresponds to “setting input means” in the present invention.

Next, the operation in the dry cooking mode performed by the high-frequency heating device in the present embodiment will be described.
The dry cooking mode is a cooking mode for performing cooking for drying the article 21 to be heated, and is roughly divided into a high-frequency heating process, a heater heating process, a finishing process, and a post-process. Hereinafter, description will be made based on the flowcharts shown in FIGS.

  When the dry cooking mode is selected on the operation panel 5, the control means 31 starts the operation of the dry cooking mode (S1). The control means 31 performs initial setting of each parameter (S2). That is, a high-frequency heating time Time 1 that is a time for performing high-frequency heating, a heater heating time Time 2 that is a time for performing heater heating, and an error such as fuming due to overheating can be caused by proceeding with heating even after drying has progressed. In order to prevent the steam from being detected, the steam non-detection time Time3 as a trigger for stopping the heating if the time is longer than a certain time, and when the temperature in the heating chamber 2 is abnormally detected as an error detection The forced stop internal temperature Temp1 is set as a trigger for stopping the heating. Further, in consideration of the case where the drying is continued gently even after the heating of the heater is finished, the cooling fan operation setting after the heater is finished (True or False) for setting whether or not the cooling fan 15 is continued after the heating of the heater is finished, and the heater After completion, the cooling fan On time Time4 is set. The high-frequency heating time Time1 and the heater heating time Time2 are set to values smaller than the steam non-detection time Time3. The cooling fan operation setting after the end of the heater corresponds to “operation setting” in the present invention.

  These temperature and time settings can be set automatically by the control means 31 by selecting a menu stored in advance even in a manual setting method arbitrarily set by the user through the operation panel 5. The method can be set in either case. Further, only the time is set and the temperature is set in advance, or the weight and the type of the object to be heated 21 are input from the weight sensor (not shown) or the operation panel 5 provided in the heating chamber 2. Thus, a method of automatically setting by the control means 31 can be configured.

(High frequency heating process)
When the setting is completed and the start of the dry cooking mode is instructed on the operation panel 5, the control means 31 operates the high-frequency oscillator 11 and starts high-frequency heating (microwave heating) (S3). When microwave heating is carried out at a high output, it becomes a high temperature in a short time, and heat denaturation of the article 21 to be heated, for example, a case where it solidifies or discolors more than expected is considered. It is desirable to carry out at the output. Even at a low output of about 200 W, the effect of promoting the movement of moisture inside the article to be heated 21 (food) to the surface side can be sufficiently ensured as compared with heating from the outside by heater heating.
During the high-frequency heating, the control means 31 appropriately controls the ON / OFF of the high-frequency oscillator 11 so that the temperature of the article 21 to be heated detected by the non-contact temperature detection means 23 is 100 ° C. or less. Variable output control may be performed.

  During high-frequency heating, steam is detected by the steam detection means 22 (S4). If steam is detected, the cooling fan 15 is turned on (S5). If steam is not detected, the cooling fan 15 is turned off and heating is performed. carry out. When it is detected that steam, that is, moisture is discharged from the object to be heated 21, air is introduced from the cooling air introduction hole 17 by the cooling fan 15 and discharged to the cooling air exhaust hole 18 as described above. For this reason, it becomes possible to accelerate | stimulate drying of the to-be-heated material 21, without a vapor | steam staying in the heating chamber 2. FIG.

In the steam detection started immediately after operating the high-frequency oscillator 11, the time during which steam is not detected is counted (S7), and when the steam non-detection time Time3 is exceeded, the operation in the dry cooking mode is forcibly terminated (S8). ), The user is notified by the notification means 5b (not shown).
Similarly, when the temperature in the heating chamber 2 detected by the ambient temperature detecting means or the non-contact temperature detecting means 23 exceeds the forced stop internal temperature Temp1, the forced termination is similarly performed.
In this step S7, it is estimated that there is a possibility that an excessive amount of heat is given to the object to be heated 21 because no steam is generated despite high-frequency heating, and as a result, the object to be heated 21 is heated. By presuming that there is a possibility of degeneration due to overheating, for example, scorching and smoke generation, and that there is a possibility of failure due to self-heating of the high-frequency oscillator 11, it is possible to prevent such a malfunction in advance. Has an effect that can be.

  When the elapsed time of the high frequency heating has passed the high frequency heating time Time1 (S9), the control means 31 stops the high frequency oscillator 11 (S10). Here, as the temperature inside the article to be heated 21 rises due to the high frequency heating, the moisture inside the article to be heated 21 is diffused to the surface side. In the subsequent heater heating process, by heating the outer surface of the heated object 21 with increased moisture content by radiation or convection, moisture evaporates from the outside, and as a result, drying progresses both inside and outside the heated object 21. Drying in a good state with a small difference in the finished state within the object to be heated 21 is possible. In other words, the high-frequency heating (drying progress) by the high-frequency heating step is positioned in a preparation stage for drying the whole well.

Here, although the steam discharge is promoted by the introduction of the cooling air 16 in step S5, the steam / moisture discharged from the object to be heated 21 is not completely discharged, for example, on the wall surface of the heating chamber 2 or the like. There may be cases where water remains in the form of condensation or water droplets or moisture remains on the surface of the heated object 21 at the stage where high-frequency heating is completed.
For this reason, in the state in which steam is detected by the steam detection means 22 after the high-frequency heating process is performed (S11), there is a concern about condensation on the wall surface of the heating chamber 2 and moisture remaining on the surface of the object 21 to be heated. Before performing the heater heating step, the user is notified that the moisture remaining in the heating chamber 2 or on the surface of the object to be heated 21 is encouraged (S12). The notification may be displayed on the operation panel 5 or may be a notification sound or a voice guide.

  The user who is prompted by the notification wipes off the residual moisture in the heating chamber 2 or the object to be heated 21 and closes the door 3 and then presses a start button (operation button) as an intention to move to the subsequent heater heating process. Thus, the process proceeds to the heater heating process (S13). Since it is necessary to give a great amount of heat as latent heat of evaporation when water such as water droplets adhering to the heating chamber 2 or the object to be heated 21 is evaporated by heater heating or the like, this wiping operation is performed. Thus, the effect of shortening the drying time obtained is great.

(Heater heating process)
Next, as a heater heating process, the control means 31 operates the heater (S14). The heater here does not limit which of the top heater 8, the bottom heater 9, and the convection unit 10 is energized. However, when it is desired to promote drying in a short time, hot air convection heating by the convection unit 10 is performed. On the other hand, when it is desired to dry uniformly in a wide range in the heating chamber 2, radiant heating by the top heater 8 and the bottom heater 9 is effective.
During the heating of the heater, the control means 31 appropriately controls the ON / OFF of the heater and the output so that the temperature of the heated object 21 detected by the non-contact temperature detecting means 23 is 100 ° C. or less. Variable control may be performed.

  Also in this step, steam detection is performed by the steam detection means 22 (S15). When steam is detected, the cooling fan 15 is turned on (S17), and when steam is not detected, the cooling fan 15 is turned off. (S16). Thereby, it becomes possible to accelerate the drying of the article to be heated 21 without the steam staying in the heating chamber 2.

In the steam detection started immediately after the heater is turned on, the time during which steam is not detected is counted (S18), and when the steam non-detection time Time3 is exceeded, the operation in the dry cooking mode is forcibly terminated (S19), and notification is made. The means 5b notifies the user (not shown).
Similarly, when the temperature in the heating chamber 2 detected by the ambient temperature detecting means or the non-contact temperature detecting means 23 exceeds the forced stop internal temperature Temp1, the forced termination is similarly performed.
In this step S18, it is estimated that there is a possibility that an excessive amount of heat is given to the object to be heated 21 because no steam is generated even though the heater is heated, and as a result, the object to be heated 21 is heated. By assuming that there is a possibility of denaturation due to overheating of, for example, scorching and smoke generation, forcibly termination, it is possible to prevent such a problem in advance.

  When the heater heating elapsed time exceeds the heater heating time Time2 (S20), the control means 31 stops the heater (S21).

(Finishing process)
Next, as a final finish of drying, heating by the high-frequency oscillator 11 is performed again for a predetermined time (S22). The predetermined time is set to be shorter than the high frequency heating time Time1 and the heater heating time Time2.
Utilizing the fact that microwaves in high-frequency heating have the property of selective heating to water, heating once again promotes evaporation of residual moisture in the form of the last push. However, since it is considered that it is almost dry and is in a light heat load state, the heating is limited to a low output and a short time of about 200 W for 30 seconds, for example. Although this finishing process is not an essential requirement, it has an effect of promoting moisture evaporation and improving the finished state as a dried product.

(Post-process)
Next, as a post process, the control means 31 turns on the cooling fan 15 (S23). By this step, it is possible to obtain the effect of discharging the steam staying in the heating chamber 2 and the effect of lowering the temperature of the heated object 21 whose temperature is slightly increased.

How to continue the operation of the cooling fan 15 is determined based on the cooling fan operation setting after the heater set in step S2 (S24). That is, when the operation setting is a setting (false) for stopping the cooling fan 15 after the heating of the heater is finished, the process proceeds to step S25, and the open state of the door 3 by the door opening / closing detection means 25 is determined (S25). When the door open / close detection means 25 detects the open state of the door 3, the cooling fan 15 is turned off (S27). If the open state of the door 3 is not detected, the cooling fan 15 is turned off after the rotation of the cooling fan 15 is continued until a predetermined time elapses (S26).
Thus, by appropriately turning the cooling fan 15 ON and OFF, it has the effect of suppressing the moisture inside the heating chamber 2 from returning to the object to be heated 21 after the heater heating step, and the failure probability of the fan motor can be reduced. An effect of suppressing wasteful power consumption can be obtained.

On the other hand, if the operation setting is set to continue the cooling fan 15 even after the end of the heater heating (true) in step S24, the door open / close detection means is used until the elapse of the cooling fan On time Time4 after the end of the heater (S28). Regardless of the detection result 25, the rotation of the cooling fan 15 is continued, and the cooling fan 15 is turned OFF when the cooling fan On time Time4 has elapsed after the heater ends (S29). For example, by driving the cooling fan 15 with the door 3 opened, it is possible to have the same effect as that of air-drying at room temperature.
The drying cooking mode of the article to be heated 21 is completed through the above steps (S30).

FIG. 8 is a graph of the weight after drying of the heated object dried by the high-frequency heating device according to the first embodiment of the present invention. FIG. 8 shows the weight (wt%) after drying when tomatoes (1/2 cut) are used as the object to be heated 21 and dry tomatoes are produced.
The graph on the left side of FIG. 8 shows the case where the dry cooking mode in the first embodiment is performed. After high-frequency heating is performed at 600 W for 3 minutes in the high-frequency heating process (range 3 minutes), the heater is heated in the heater heating process. Is performed for 57 minutes (oven 57 minutes), and the total weight after drying is shown.
Moreover, the graph on the right side of FIG. 8 shows the weight after drying when the heater is heated alone for 60 minutes (oven 60 minutes).
Moreover, the center graph of FIG. 8 has shown the weight after drying when a high frequency heating is performed only for 3 minutes at 600 W (range 3 minutes alone) as a reference value.
In the heater heating, the temperature in the heating chamber 2 is controlled to 100 ° C. to 105 ° C. and the convection unit 10 is not used.

As shown in FIG. 8, when the heater heating alone is performed for 60 minutes (oven 60 minutes), the weight is 73.8%, whereas when the dry cooking mode in the present embodiment is performed (range 3 minutes → The weight of the oven 57 minutes) is 43.0%. That is, the weight reduction rate that seems to be almost the same as the amount of water evaporation is twice or more in the drying cooking mode in this embodiment compared to the heater heating alone, and has a great effect on improving the drying speed. I understood.
In addition, the weight in the case of the range for 3 minutes alone is 68.3%, which shows that the moisture evaporation effect by the high frequency heating is large, and the high frequency heating and the heater heating are performed as in the dry cooking mode of the present embodiment. It has been found that the use of is extremely effective for the progress of drying.
For reference, the dried food was firmer and richer in taste when dried in the dry cooking mode in the present embodiment, compared to drying with heater heating alone.

As described above, in the present embodiment, by performing high-frequency heating in the initial stage of heating, the inside of the object to be heated 21 that is difficult to receive heat from the outside is heated, so that the moisture in the object to be heated 21 is brought to the surface. Because it is possible to promote drying by moving, for example, even thick foods can be brought to the inside in a short time compared to drying at room temperature or drying with heater heating alone. There is an effect that good drying can be realized.
In particular, selective heating of moisture, which is a characteristic of high-frequency heating, is possible, so that there is an effect that the temperature of moisture rises quickly, and further, evaporation can be promoted and food can be dried at high speed.
Furthermore, since the ventilation for discharging the steam in the heating chamber 2 to the outside of the heating chamber 2 after the high-frequency heating is performed simultaneously with the heating, moisture evaporated from the object to be heated 21 stays in the heating chamber 2 or the heating chamber It is possible to suppress the possibility that a problem occurs that the condensation on the wall surface in 2 causes the drying of the article to be heated 21 to reverse.

  As an application example of the present invention, application to a high-frequency heating apparatus for business use and home use capable of producing a dry food safely at high speed can be mentioned.

  DESCRIPTION OF SYMBOLS 1 Main body, 2 Heating chamber, 3 Door, 4 Viewing window, 5 Operation panel, 5a Input means, 5b Notification means, 6 Bottom ceramic board, 7 Rail, 8 Top heater, 8a Thermal insulation, 9 Bottom heater, 10 Convection unit 10a convection heater, 10b convection fan, 10c punching hole, 11 high frequency oscillator, 12 waveguide, 13 rotating antenna, 14 antenna motor, 15 cooling fan, 16 cooling air, 17 cooling air introduction hole, 18 cooling air exhaust hole, 19 exhaust duct, 20 tray, 20a open part, 20b convex part, 21 object to be heated, 22 vapor detection means, 23 non-contact temperature detection means, 24 high frequency oscillator temperature detection means, 25 door open / close detection means, 31 control means, 32 Main board, 33 power supply, 36 relay, 37 inverter substrate.

Claims (15)

A heating chamber for storing an object to be heated;
A high-frequency oscillator that heats the object to be heated by supplying a high frequency into the heating chamber;
A heater that is installed on at least one of the wall surfaces of the heating chamber and heats the object to be heated and the heating chamber;
At least setting input means for inputting an operation related to selection of the heating mode,
According to the selected heating mode, the high-frequency oscillator and a control means for controlling the heating operation of the heater,
The control means includes
As the heating mode, it has a dry cooking mode for cooking to dry the object to be heated,
In the dry cooking mode,
A high-frequency heating apparatus that performs a heater heating step of performing heating by the heater after performing a high-frequency heating step of performing heating by the high-frequency oscillator. A cooling fan for supplying cooling air to the high-frequency oscillator;
An air passage for guiding the cooling air into the heating chamber;
A discharge port for discharging the cooling air guided into the heating chamber to the outside of the heating chamber;
The control means includes
In the dry cooking mode,
2. The high frequency heating apparatus according to claim 1, wherein the cooling fan is operated to discharge the steam in the heating chamber to the outside of the heating chamber. Comprising a steam detection means for detecting the presence or absence of steam in the heating chamber;
The control means includes
In the dry cooking mode,
The high frequency heating apparatus according to claim 2, wherein when the steam is detected by the steam detecting means, the cooling fan is operated. The control means includes
In the dry cooking mode,
4. The high frequency heating apparatus according to claim 3, wherein when the state in which the steam is not detected by the steam detection means continues for a predetermined time or longer, the heating operation of the high frequency oscillator and the heater is stopped. A high-frequency oscillator temperature detecting means for detecting the temperature of the high-frequency oscillator;
The control means includes
When the temperature of the high-frequency oscillator exceeds a predetermined temperature, the cooling fan is operated,
In the dry cooking mode,
5. The high frequency heating apparatus according to claim 3, wherein the cooling fan is operated when steam is detected by the steam detection means regardless of the temperature of the high frequency oscillator. 6. Providing a notification means,
The control means includes
After performing the high-frequency heating step and before performing the heater heating step,
The high-frequency heating device according to any one of claims 1 to 5, wherein the notification means notifies that the moisture in the heating chamber or the object to be heated is wiped off. Non-contact temperature detection means for detecting the temperature of the object to be heated in a non-contact manner,
The control means includes
In the dry cooking mode,
The heating operation of the high-frequency oscillator and the heater is controlled so that the temperature of the object to be heated detected by the non-contact temperature detecting means is 100 ° C. or less. The high-frequency heating device according to one item. The control means includes
In the dry cooking mode,
8. The high frequency heating apparatus according to claim 7, wherein when the temperature of the object to be heated detected by the non-contact temperature detecting means exceeds a predetermined temperature, heating operation of the high frequency oscillator and the heater is stopped. Comprising an ambient temperature detection means for detecting the ambient temperature in the heating chamber;
The control means includes
In the dry cooking mode,
The heating operation of the high-frequency oscillator and the heater is stopped when the temperature in the heating chamber detected by the ambient temperature detection means exceeds a predetermined temperature. The high-frequency heating device described. The control means includes
After performing the heater heating step,
The high-frequency heating apparatus according to any one of claims 1 to 9, wherein a finishing step is performed in which heating by the high-frequency oscillator is performed for a predetermined time. A door for opening and closing the heating chamber;
Open / close detecting means for detecting the open / closed state of the door,
The control means includes
After performing the heater heating step, the cooling fan is operated,
The high-frequency heating device according to any one of claims 2 to 10, wherein when the open / closed detection means detects the open state of the door, the operation of the cooling fan is stopped. The control means includes
Obtain an operation setting in which the necessity of operation of the cooling fan after the heater heating step is set,
After performing the heater heating step, the cooling fan is operated,
12. The high frequency according to claim 11, wherein when the operation setting is a setting for operating the cooling fan, the operation of the cooling fan is continued for a predetermined time regardless of a detection result of the open / close detection means. Heating device. The heater is
It is constituted by a convection unit that inhales air in the heating chamber, heats the air and discharges it into the heating chamber, and performs hot air convection heating,
The control means includes
In the heater heating step,
The high frequency heating apparatus according to any one of claims 1 to 12, wherein the convection unit is operated and the object to be heated is dried by hot air convection heating. A tray installed in the heating chamber, on which the object to be heated is placed;
The tray is
The high-frequency heating device according to any one of claims 1 to 13, wherein at least one of unevenness and an opening is formed in a region where the object to be heated is placed. The tray is
15. The high frequency heating apparatus according to claim 14, wherein the high frequency heating apparatus is formed of a material containing a high frequency heating element that generates heat when irradiated with a high frequency.

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