KR20080114499A - Cooker - Google Patents

Abstract

A cooking device is provided to control precisely the cooking temperature at desired temperature by precisely controlling amount of steam generating. A cooking device comprises a housing(11) forming a cavity which accommodates a cooking stuff and cooks it; a temperature setup unit setting up the cooking temperature heating and cooking the cooking stuff; a room temperature detection unit detecting actual temperature inside the cooking stuff; a reservoir(21) storing water; a feed part(22) supplying water to the reservoir; a heating part(23) heating up the reservoir; a steam supply unit(20) supplying steam generated into the cooking cavity; and a control part controlling the temperature of the reservoir which allows the actual temperature detected by an actual temperature detection part to reach the setup temperature.

Description

Cooker {COOKING DEVICE}

The present invention relates to a heat cooker, and more particularly to a heat cooker having a heating cooking function by steam.

Conventionally, in addition to heating cooking by an electric fire or magnetron, a heating cooker which enables heating cooking by steam is provided. As disclosed in, for example, Japanese Laid-Open Patent Publication No. 2005-308315, the steam provided for the heating cooking is provided with a reservoir for storing water in the cooking chamber or its vicinity, and the water stored in the reservoir is It occurs by heating and boiling. Further, Japanese Laid-Open Patent Publication No. 2005-308315 discloses a configuration or method for comparing the set cooking temperature with the actual temperature in the cooking chamber and changing the amount of steam generation based on the result.

By the way, depending on a cooking menu, cooking may be performed by maintaining the temperature of a cooking chamber at 100 degrees C or less. For example, when fermenting bread dough, the cooking temperature is maintained in the range of 30 ° C to 50 ° C. In addition, for example, when a liquid pudding raw material (pudding raw material) or the like is made by steaming, the cooking temperature is maintained at about 80 ℃. In recent years, it has been known to increase the vitamin C in foods by maintaining the cooking temperature in the range of 40 ° C to 50 ° C.

In the heating cooker disclosed in Japanese Laid-Open Patent Publication No. 2005-308315, it is very difficult to control such that the actual temperature of the cooking chamber is strictly maintained at a desired set temperature. This is because the temperature of the water stored in the reservoir cannot be changed quickly. The amount of water vapor generated from the reservoir depends on the temperature of the water stored in the reservoir. Therefore, if the temperature change of the water stored in the storage part is not rapid, the amount of water vapor generated cannot be precisely controlled. That is, when the water stored in the reservoir simply boils, the heating cooker disclosed in JP-A-2005-308315 cannot precisely control the amount of water vapor generated from the reservoir. As a result, it is very difficult to precisely control the cooking temperature.

For example, when increasing the amount of water vapor generated to raise the cooking temperature, it is necessary to increase the temperature of the water stored in the reservoir. In addition, the rate of increase of the water temperature is determined by the specific heat of water and the energy used for heating. However, since the specific heat of water is large and there is a limit to the power that can be consumed in household appliances such as heating cookers, the temperature rise of the water temperature cannot be made very fast. On the other hand, when reducing the amount of water vapor generated, it is necessary to quickly lower the water temperature of the water stored in the reservoir. However, since the specific heat of water is large, the fall of the water temperature is slow, and in this case, too, the rate of decrease of the water temperature cannot be accelerated much.

As described above, in the conventional apparatus, when steam is generated by heating and boiling the water in the reservoir, the response of the control for manipulating the amount of steam generated is poor. Therefore, even if the cooking temperature is adjusted to the desired set value by controlling the amount of steam generated, the amount of generated steam does not change quickly, and as a result, there is a problem that the cooking temperature fluctuates significantly above and below the set value.

The present invention has been made in view of the above problems in the conventional apparatus, and an object thereof is to provide a heating cooker in which the cooking temperature is precisely controlled to a desired set temperature by precisely controlling the amount of steam generated.

In order to achieve the above object, the heat cooker of the present invention includes a housing for forming a cooking compartment for accommodating food, cooking temperature setting means for setting a cooking temperature for heating and cooking the food, and an actual temperature in the cooking chamber. Room temperature detection means for detecting, a reservoir for storing water, a replenishment for replenishing water to the reservoir, and a heater for heating the reservoir, wherein the heater is used to generate steam by heating the reservoir. And the water storage unit so as to compare the actual temperature detected by the steam supply means for supplying the generated steam to the cooking chamber and the actual temperature detected by the room temperature detection means with the set temperature, and the actual temperature becomes the set temperature according to the difference. And a control unit for controlling the temperature.

The controller controls the temperature of the reservoir. The amount of water vapor generated in the reservoir varies with the temperature of the reservoir. Therefore, by controlling the temperature of the reservoir, the amount of water vapor supplied to the cooking chamber is quickly controlled. Therefore, the amount of steam generated can be precisely controlled, and the cooking temperature can be controlled quickly and precisely to a desired set temperature.

Hereinafter, an embodiment of a heating cooker according to the present invention will be described based on the drawings.

One embodiment of a heat cooker according to the present invention is shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram which shows the structure of the principal part of a heating cooker. In addition, in order to make description easy, well-known exterior members, such as a door and an operation button provided in the front surface, are abbreviate | omitted in FIG.

The heat cooker 10 has a box-shaped housing 11. The housing 11 has a cooking chamber 12 formed therein. The food to be cooked is accommodated in the cooking chamber 12. The heat cooker 10 is provided with the heater 13 as a heating means for heating and cooking the food accommodated in the cooking chamber 12. The heater 13 is provided on the rear wall of the housing 11 which forms the cooking chamber 12. The heater 13 is formed in arbitrary frame shapes, such as rectangular shape or circular shape, as shown in FIG. The circulation fan 14 is disposed inside the frame heater 13. The circulation fan 14 forms an air flow in the cooking chamber 12, and maintains the temperature in the cooking chamber 12, that is, the cooking temperature, in a nearly stable state.

When the circulation fan 14 is driven, the air in the cooking chamber 12 circulates through the cooking chamber 12 while passing through the heater 13. As a result, when the heater 13 is energized, the air in the cooking chamber 12 is heated by the heater 13, and the cooking chamber 12 is also heated. On the other hand, when the heater 13 is not energized, the air in the cooking chamber 12 circulates through the cooking chamber 12 without being heated by the heater 13.

The heat cooker 10 is equipped with the steam supply apparatus 20 as a steam supply means. The steam supply device 20 includes a water storage unit 21, a supply unit 22, a heating unit 23, a thermistor 24 as a water storage unit temperature detecting means, and a preheating unit 25. The reservoir 21 is provided on the bottom wall of the housing 11. The reservoir 21 is formed in a container shape for storing water supplied from the replenishment 22. The supply section 22 has a water supply tank 26, a water supply pump 27, a water supply pipe 28, and the like. The water supply tank 26 is detachably installed from the housing 11 and stores water supplied to the reservoir 21. The feed pump 27 supplies the water stored in the feed tank 26 to the reservoir. Water sucked from the water supply tank 26 by the water supply pump 27 is supplied to the water storage part 21 via the water supply pipe 28. The thermistor 24 is provided in the reservoir 21, and detects the temperature of the water in the reservoir 21. The control part 30 shown in FIG. 2 controls the electricity supply to the heating part 23 based on the temperature of the water storage part 21 which the thermistor 24 detected. The preheater 25 heats the water supplied from the water supply tank 26 to the reservoir 21. As a result, the water supplied from the water supply tank 26 to the water storage portion 21 is preheated to a predetermined temperature before flowing into the water storage portion 21.

The heating part 23 is provided in the water storage part 21. The water storage part 21 is formed in a container shape by aluminum die casting, etc., and the heater which comprises the heating part 23 is attached. Therefore, the water stored in the storage part 21 is heated by energizing the heating part 23. As a result, water vapor is generated in the reservoir 21. The generated water vapor is supplied to the cooking chamber 12 from the bottom wall side of the housing 11.

In addition to the above-mentioned heating means, the heat cooker 10 may be configured to include, for example, a surface heater for a magnetron or a grill. The magnetron is installed outside the housing 11 forming the cooking chamber 12 and generates a high frequency. The high frequency generated in the magnetron is irradiated to the cooking chamber 12 from the bottom wall side of the housing 11 via a waveguide, for example. Moreover, the planar heater is provided in the ceiling wall side of the housing 11 which forms the cooking chamber 12, and generate | occur | produces electromagnetic waves, such as infrared rays. Electromagnetic waves generated by the heater are irradiated to the cooking chamber 12 from the ceiling wall side of the housing 11, for example.

The heat cooker 10 is provided with the ventilation means not shown. The ventilation means is provided with an intake port, an exhaust port, a ventilation fan, etc. which are not shown in figure. The ventilation means introduces external air into the cooking chamber 12 by driving the ventilation fan and also discharges the air of the cooking chamber 12 to the outside. The cooking chamber 12 is provided with a temperature sensor 15 as a cooking chamber temperature detecting means. The temperature sensor 15 has a thermistor etc., for example, and detects the actual temperature of the cooking chamber 12, ie, room temperature.

Next, the main part of the electrical structure of the heating cooker 10 is demonstrated based on FIG. In addition, FIG. 2 especially shows the electrical structure related to the steam supply apparatus 20, and abbreviate | omits the structure of other heating means, such as a magnetron and a grill heater, for example. The control part 30 which controls the whole heating cooker 10 is comprised mainly by the microcomputer which has CPU, RAM, ROM, etc. The control unit 30 controls each unit of the heating cooker 10 according to the control program stored in the ROM. Specifically, the control part 30 is preset cooking based on the operation input selectively performed from the operation part 31 provided in the outer side of the housing 1, such as a key and a switch, for example. According to the menu, the entire heating cooker 10 is controlled. Therefore, various input signals by operation of the keys and switches of the operation part 31, the temperature detection signal from the temperature sensor 15, the temperature detection signal from the thermistor 24, etc. are input to the control part 30. In addition, the control part 30 inputs the set temperature of the cooking chamber 12 by operation of the operation part 31. FIG. That is, a user inputs a cooking menu by operating the operation part 31 as cooking temperature setting means. The control unit 30 sets a cooking temperature suitable for the cooking menu based on the cooking menu input via the operation unit 31.

On the other hand, the circulation fan 14, the feed water pump 27 of the supply part 22, the heating part 23, the preheating part 25, the heater 13, etc. are connected to the output side of the control part 30. These circulation fans 14, feed water pump 27, heating section 23, preheating section 25, and heater 13 are each controlled by the control unit 30 via a driving circuit not shown.

Next, operation | movement of the heat cooker 10 of the said structure is demonstrated.

In the heating cooker 10 as a general use method, the control unit 30 is a high frequency heating cooking by a magnetron (not shown) or a grill (not shown) installed on the ceiling wall side based on setting operations such as a cooking menu of the operation unit 31. Heating cooking using radiant heat by the heater, and hot air oven heating cooking by the heater 13 and the circulation fan 14 which generate circulating hot air can be selectively performed. At that time, based on the actual temperature of the cooking chamber 12 detected by the temperature sensor 15, the control unit 30 controls the cooking chamber 12 to a preset programmed temperature. Thereby, heating cooking of the food accommodated in the cooking chamber 12 is performed.

The heat cooker 10 of this embodiment can perform cooking of various cooking menus using the steam supply device 20 alone or in combination with other heating means by using the steam supply device 20 as a heating means. Specifically, by using the steam supply device 20 of the heat cooker 10 alone or in combination with other heating means, for example, "teriyaki chicken", "hamburger", "pot-steamed hotchpotch" ) "And" Heating such as boiled rice and steamed meat bun, "as well as cooking that is expected to increase vitamin C such as" pudding "and" vegetables " Steam cooking suitable for a menu such as "cooking".

Therefore, according to the setting or the selected cooking menu, the control part 30 is the same as the cooking menu in the high temperature mode which sets the temperature (equivalent to the cooking temperature) of the cooking chamber 12 higher than 100 degreeC which is a boiling point of water, for example. The cooking menu in the low temperature mode set below the boiling point can be controlled respectively. For example, in the cooking menu, steam cooking menus such as "chicken seasoning" and "hamburger" are executed in a high temperature steam cooking mode in which the cooking temperature is higher than the boiling point of water. On the other hand, steam cooking menus such as "steaming egg", "heating such as rice and meat dumplings", "pudding" and "vitamin C increased cooking" are executed in a low temperature steam cooking mode where the cooking temperature is below the boiling point of water.

In the case of performing cooking, desired food is accommodated in the cooking chamber 12 before starting cooking, and the operation part 31 sets or selects the conditions of the heating cooking by steam. The control unit 30 controls the heating cooking based on a program set in advance by a signal from the input operation unit 31. Specifically, when the heating cooking is started, the controller 30 determines whether the set temperature used for the setting or the selected cooking menu is high temperature cooking higher than the boiling point of water, based on the setting or the input of setting the selected cooking menu or the weight of the food. It is determined whether it is low temperature cooking below the boiling point of water.

For example, when the cooking menu of "grilled chicken seasoning" is set or selected, the cooking menu is classified as high temperature cooking. Therefore, the control part 30 drives the circulation fan 14 to normal rotation, and supplies the air heated by the heater 13 to the cooking chamber 12. Thereby, the hot air is circulated in the cooking chamber 12. In addition, when the cooking menu of "grilled chicken seasoning" is set or selected, the so-called superheated steam at a saturation temperature or higher is supplied from the steam supply device 20 to the cooking chamber 12, so-called steam cooking is performed.

Specifically, the control part 30 energizes the heating part 23, and heats the water storage part 21 to about 120 degreeC by the heating part 23, for example. The control part 30 drives the water supply pump 27 of the replenishment part 22, when the thermistor 24 detects that the temperature of the water storage part 21 reached 120 degreeC. As a result, a small amount of water is supplied from the water supply tank 26 to the water storage portion 21 intermittently via the water supply pipe 28. The water supplied to the reservoir 21 heated to a high temperature is heated and evaporated, and water vapor of 100 ° C. or higher is supplied to the cooking chamber 12. As described above, the cooking chamber 12 is circulated with hot air. Therefore, the water vapor also circulates with the hot air and is repeatedly heated by the heater 13. As a result, the steam of the cooking chamber 12 is produced as superheated steam heated above the saturation temperature. The controller 30 maintains the cooking chamber 12 at the set temperature based on the actual temperature of the cooking chamber 12 detected by the temperature sensor 15. Thereby, heating cooking by superheated steam is performed.

On the other hand, when the "pudding", the "vitamin C increase cooking" menu, etc. are set or selected, for example, these cooking menus are classified as low temperature cooking. Therefore, the control part 30 rotationally drives the circulation fan 14 at a lower speed than the normal rotation, and turns off the energization to the heater 13 (turn-off). The controller 30 generates the low temperature steam by the steam supply device 20 and supplies the steam to the cooking chamber 12.

Thus, the control part 30 introduces water vapor into the cooking chamber 12, and balances the heat quantity of this steam with the heat quantity by the external air which leaks into the cooking chamber 12, or heat dissipation to the outside, and the cooking chamber 12 is carried out. Is controlled to 100 ° C or less. Since water vapor has a large heat capacity, the temperature stability of water vapor is high. Therefore, control of the temperature of the cooking chamber 12 is facilitated by introducing water vapor into the cooking chamber 12. For example, when "pudding" is selected as the cooking menu, the cooking chamber 12 is controlled at 80 ° C. In addition, when "vitamin C increase cooking" is selected as a cooking menu, the cooking chamber 12 is controlled to 40 to 50 degreeC.

The amount of steam generation required to control the cooking chamber 12 to the set temperature depends on the temperature in the stable state of the cooking chamber 21 as shown in FIG. 3. For example, as the set temperature of the cooking chamber 12 increases, the difference with the external temperature of the heating cooker 10 becomes large, and the cooking chamber 12 becomes easy to cool. Therefore, in order to maintain the cooking chamber 12 at a preset temperature, more heat quantity of water vapor is required. Therefore, the amount of steam required as determined by the set temperature is determined, and the cooking chamber 12 is controlled to the set temperature by changing the amount of steam generated according to the set temperature.

Here, the amount of steam generated is controlled by the temperature of the reservoir 21. If the surface area of the water stored in the storage part 21 is the same, as shown in FIG. 4, as the temperature of the storage part 21 increases, the amount of generation of water vapor will increase. Here, the temperature of the water storage part 21 means the temperature of the water stored in the water storage part 21, and may be the temperature of the cooking container accommodated in the water storage part 21 detected by the thermistor 24. In addition, the temperature of the water stored in the reservoir 21 may be used. When the water in the reservoir 21 is in a boiling state, water vapor of 100 ° C. is generated. In this way, by controlling the temperature of the water storage portion 21 to a predetermined temperature, the amount of water vapor generated from the water storage portion 21 can be controlled. For example, as the set temperature is lowered from 80 ° C to 40 ° C, the temperature of the reservoir 21 is also controlled to be lowered, for example, from 95 ° C to 85 ° C. Thereby, the amount of steam suitable for each set temperature is supplied, and it becomes easy to keep the temperature of the cooking chamber 12 constant. When the temperature of the reservoir 21 is maintained at 100 ° C., the amount of water vapor generated is maximum, and the temperatures of the reservoir 21 are 95 ° C., 90 ° C.,. As the temperature decreases, the amount of generated water vapor decreases. Moreover, when the temperature of the water storage part 21 is less than 100 degreeC, the quantity of water vapor | steam produced gradually falls compared with the time of boiling. Therefore, in order to ensure the required amount of water vapor, for example, the boiling state is such that the temperature of the reservoir 21 continues boiling at 100 ° C. for 2 seconds and then continues boiling at less than 100 ° C. for 5 seconds. The amount of water vapor generated may be controlled by dividing and repeating the boiling and boiling conditions in time.

The controller 30 controls the temperature of the reservoir 21 according to the set temperature. As shown in FIG. 5, the controller 30 changes the time ratio (hereinafter, referred to as a boiling rate) of water stored in the water storage unit 21 in a boiling state per unit time (hereinafter, referred to as a boiling rate). 21) to control the temperature. If the water in the reservoir 21 is always in a boiling state per unit time, the boiling rate is 100% and the amount of water vapor generated is maximum. On the other hand, as the boiling rate per unit time decreases, the amount of water vapor generated from the reservoir 21 decreases. Therefore, when the actual temperature of the cooking chamber 12 becomes higher than the set temperature, the amount of steam required to maintain the set temperature decreases, and the boiling rate also decreases. In addition, when the actual temperature is lower than the set temperature, the amount of steam required to maintain the set temperature increases and the boiling rate also increases. Thus, the control part 30 controls the temperature of the cooking chamber 12 with the temperature of the water storage part 21 by changing the boiling rate per unit time of the water storage part 21 according to the set temperature.

By the way, if the temperature of the place where the heating cooker 10 is installed and the heat absorption amount of the food to be cooked are different, for example, even if the set temperature is the same, the amount of heat required is changed. Therefore, the optimum temperature of the water storage part 21 required for generating the amount of steam corresponding to the set temperature may vary. Therefore, the control part 30 adjusts the temperature of the water storage part 21 based on the difference of the actual temperature of the cooking chamber 12 detected by the temperature sensor 15, and set temperature. The temperature of the water storage part 21 is controlled by changing the boiling rate per unit time in the water storage part 21 as shown in FIG. For example, when the optimum setting value of the temperature control of the water storage part 21 set in accordance with the set temperature is a combination of boiling 2 seconds and boiling 4 seconds, the actual temperature of the cooking chamber 12 is greater than the set temperature. When lowered, the amount of steam generated is increased by extending the boiling time to 2 seconds or more or shortening the boiling time to 4 seconds or less. On the other hand, if the actual temperature of the cooking chamber 12 is higher than the set temperature under the above conditions, the amount of steam generated is reduced by shortening the boiling time to 2 seconds or less or extending the boiling time to 4 seconds or more. In this way, the control unit 30 precisely controls the cooking chamber 12 at the set temperature in accordance with the actual temperature by changing the boiling rate in the water storage unit 21.

In addition, when raising the temperature of the cooking chamber 12 from room temperature to a desired set temperature, temperature control of the cooking chamber 12 is divided into the temperature rise which rises from room temperature to a set temperature, and the temperature stable maintenance maintained at a set temperature. . As shown in FIG. 7, when the temperature rises, the controller 30 increases the boiling rate of the water storage unit 21 to increase the amount of water vapor supplied to the cooking chamber 12, and increases the temperature of the cooking chamber 12. Promote. Then, as the actual temperature of the cooking chamber 12 approaches the set temperature, the boiling rate in the reservoir 21 is gradually lowered by changing the temperature of the reservoir 21 so that the actual temperature is stabilized at the preset temperature. Reduces the amount of In addition, when the actual temperature of the cooking chamber 12 reaches the set temperature, the controller 30 maintains the cooking chamber 12 at a predetermined set temperature as shown in FIG. 6. In addition, the amount of steam generated may be reduced so that the rate of change becomes smoother as the actual temperature of the cooking chamber 12 approaches the set temperature, or may be continuously reduced at a constant rate of change. In addition, at the time of temperature rise, not only the cooking chamber 12 is heated by supply of the steam from the steam supply apparatus 20, but is also energized by the heater 13 auxiliary, for example, and the structure which accelerates heating of the cooking chamber 12 is carried out. You may make it.

The amount of water vapor generated may be controlled by not only changing the boiling rate in the reservoir 21 as described above but also by changing the amount of water stored in the reservoir 21. If the energy supplied to the heating part 23 of the water storage part 21 is the same, the time required for the temperature change of water changes with the quantity of the water stored in the water storage part 21. For example, if the amount of water stored in the reservoir 21 is small, the time required for raising or lowering the temperature of the water is short, i.e., the rate of change of the temperature becomes large. On the other hand, if the amount of water stored in the reservoir 21 is large, the time required for raising or lowering the temperature of the water is long, that is, the rate of change of the temperature is small. Therefore, while the amount of water stored in the storage portion 21 increases in a short time when the amount of water stored in the storage portion 21 is small, it takes time to increase the amount of water vapor generated when the amount of water stored in the storage portion 21 is large. do.

For example, as shown in FIG. 8, the bottom part of the reservoir part 21 and the heating part 23 are inclined with respect to the horizontal direction, so that the surface area of the water stored in the reservoir part 21, that is, the evaporation surface The area is changed. Specifically, when the amount of stored water is small as shown in Fig. 8A, the surface area of the stored water is small, and the amount of stored water is large as shown in Fig. 8B. At that time, the surface area of the stored water becomes large. Therefore, when the amount of water stored in the reservoir 21 is small and the surface area is small, the amount of vapor evaporated increases. When the amount of water stored in the reservoir 21 is large and the surface area is large, the vapor vaporizes. The amount of decreases.

By controlling the amount of water stored in the reservoir 21 as described above, the amount of water vapor generated and the rate of change of the amount generated are controlled. Therefore, as shown in FIG. 9, the control unit 30 controls the amount of water stored in the water storage unit 21 in accordance with the set temperature. In addition, the relationship between the set temperature and the amount of water stored in the reservoir 21 may be set step by step as shown in FIG. 9, or may be set to change continuously. In addition, the shape of the water storage part 21 shown in FIG. 8 is an example, For example, by setting the shape of the water storage part 21 arbitrarily, the area of the evaporation surface changes with the liquid surface position of the water storage part 21. It is good also as a structure.

As described above, the control unit 30 may change the amount of water stored in the water storage unit 21 at the time of the temperature rise and the temperature stable maintenance. Specifically, as shown in FIG. 10, when the temperature rises, the amount of water stored in the reservoir 21 and the amount of steam supplied to the cooking chamber 12 are increased to promote an increase in the temperature of the cooking chamber 12. As the temperature approaches the set temperature, the amount of water stored in the water storage unit 21, that is, the amount of water vapor generated, is gradually reduced so that the actual temperature is stabilized at the set temperature. The amount of water stored in the reservoir 21 may be gradually decreased as it approaches the set temperature, or may be continuously reduced at a constant rate of change. By reducing the amount of water stored in the reservoir 21 at a temperature close to the set temperature, the amount of steam generated and the rate of generation of water vapor are more precisely controlled. As a result, in the present embodiment, the change in the actual temperature of the cooking chamber 12, so-called ripple, is reduced in comparison with the conventional example as shown in FIG. 11 in the vicinity of the set temperature.

By generating steam from the reservoir 21, the amount of water stored in the reservoir 21 is reduced. Therefore, the control part 30 controls the quantity of the water supplied to the water storage part 21 so that the predetermined | prescribed amount of water vapor supplied from the water storage part 21 to the cooking chamber 12 may be maintained. The control part 30 detects the quantity of water supplied from the water supply tank 26 to the water storage part 21 based on the operating time of the water supply pump 27, ie, the energization time to the water supply pipe 27. In addition, the water quantity sensor may be provided in the water storage part 21, and the control part 30 may be set as the structure which detects the quantity of water of the water storage part 21 from the output signal of a water quantity sensor.

Thus, the water supplied from the water supply tank 26 to the water storage part 21 is preheated by the preheating part 25 normally. The preheating part 25 heats the water stored in the water supply tank 26 at the temperature near room temperature to the temperature of the water storage part 21. The water stored in the water supply tank 26 is almost room temperature, and the temperature is lower than that of the water storage portion 21. Therefore, if the water of the water supply tank 26 is supplied to the water storage part 21 as it is, the temperature of the water storage part 21 may fall and it may interfere with the precise control of the amount of water vapor generated from the water storage part 21. . Thus, the preheater 25 heats the water supplied to the reservoir 21 to a temperature close to the reservoir 21. Thereby, even if water is supplied from the water supply tank 26 to the water storage part 21, the temperature change of the water storage part 21 will reduce. In addition, the control part 30 may control the temperature of the water heated by the preheating part 25 based on the preset temperature of the cooking chamber 12 or the difference of a preset temperature and an actual temperature. In this way, by controlling the temperature of the water heated by the preheater 25, the temperature of the cooking chamber 12 is more precisely controlled based on the set temperature and the actual temperature.

On the other hand, as shown in Figs. 7 and 10, when the temperature state of the cooking chamber 12 is controlled separately from the temperature rise and the temperature stable time, as shown in FIG. Therefore, while the actual temperature of the cooking chamber 12 rises to the set temperature, the actual temperature of the cooking chamber 12 is kept substantially constant at the set temperature regardless of the heating time during the temperature stabilization. Therefore, as shown in Fig. 12B, the amount of steam required at the time of temperature stability holding decreases with respect to the amount of steam required at the time of temperature rise. In this way, when the actual temperature of the cooking chamber 12 reaches the set temperature and shifts from the temperature rise to the temperature stable holding time, the required amount of water vapor greatly changes.

As described above with reference to FIG. 4, the amount of water vapor generated in the reservoir 21 changes according to the temperature of the reservoir 21. Therefore, when the amount of water vapor required by shifting from the temperature rise to the temperature stable maintenance is reduced, it is necessary to reduce the temperature of the water storage part 21 in accordance with the amount of water vapor required at the temperature stable maintenance. However, since the specific heat of water is large and a relatively large amount of water is stored in the water storage part 21 at the time of temperature rise, the temperature drop of the water storage part 21 becomes gentle only by stopping the electricity supply to the heating part 23. .

Therefore, in the present embodiment, the control unit 30 supplies the water from the water supply tank 26 to the water storage unit 21 while stopping the energization to the preheater 25 when the temperature is shifted from the temperature rise to the temperature stable maintenance time. . Thereby, the water supplied from the water supply tank 26 to the water storage part 21 is not heated by the preheating part 25, but becomes temperature near the room temperature of low temperature compared with the temperature of the water storage part 21. FIG. At this time, the control part 30 may increase the quantity of water supplied to the water storage part 21 by the feed water pump 27 than usual, and may promote the temperature fall of the water storage part 21 more.

Thus, while the heating by the preheating part 25 is stopped between the time of temperature rise and the temperature stable maintenance, and the water supply amount by the feed water pump 27 is increased, the water storage part 21 has more water near room temperature than usual. Supplied. As a result, the temperature of the water storage part 21 falls rapidly. As a result, when the temperature shifts from the temperature rise to the temperature stable maintenance time, the temperature of the water storage portion 21 is rapidly lowered, and the amount of water vapor generated in the water storage portion 21 is rapidly reduced. Therefore, the temperature of the cooking chamber 12 is precisely maintained at the set temperature.

In addition, in the present embodiment, as shown in Fig. 13, a cooling fan 16 as cooling means for cooling the housing 11 may be provided. The cooling fan 16 blows to the outer wall of the housing 11 forming the cooking chamber 12 to cool the housing 11. Thereby, the cooking chamber 12 which the housing 11 forms is cooled, and temperature falls. The cooling fan 16 is connected to the control part 30 shown in FIG. 2 via the cooling fan drive circuit which is not shown in figure. As a result, the control unit 30 turns on or off the driving of the cooling fan 16 based on, for example, the set temperature.

For example, when controlling the temperature of the cooking chamber 12 to 100 degrees C or less, especially close to room temperature like the "vitamin C increase cooking" menu etc., the difference between the temperature of the cooking chamber 12 and room temperature becomes small. Therefore, the temperature of the cooking chamber 12 reaches the set temperature only by supplying a small amount of water vapor from the steam supply device 20 to the cooking chamber 12. As a result, it becomes difficult to supply a large amount of steam to the cooking chamber 12, and there exists a possibility that the temperature stabilization control using water vapor with a large specific heat may be impaired. On the other hand, when the outside air at room temperature is introduced for the purpose of lowering the temperature of the cooking chamber 12, a difference occurs in the temperature at a place far from the outside air inlet of the cooking chamber 12, or water vapor in the cooking chamber 12 is introduced. The amount of is lowered. As a result, there exists a possibility that the temperature stabilization control using water vapor with a large specific heat may be inhibited as mentioned above.

Therefore, in this embodiment, the housing 11 which forms the cooking chamber 12 by the cooling fan 16 is cooled. Thereby, the housing 11 which forms the cooking chamber 12 is cooled by the outside air blown out from the cooling fan 16 at the outer side. Therefore, heat dissipation from the housing 11 is accelerated | stimulated, and the temperature of the cooking chamber 12 falls easily. As the temperature of the cooking chamber 12 decreases, the amount of steam that can be supplied from the steam supply device 20 to the cooking chamber 12 increases. As a result, the density of water vapor rises and stable temperature control of the cooking chamber 12 becomes possible. In addition, the cooling means is not limited to the cooling fan 16, For example, you may use a Ferche element, a coolant, etc.

As described above, especially when the temperature of the cooking chamber 12 is maintained at about 40 ° C. as in the “vitamin C increased cooking” menu, the cooling effect by the cooling fan 16 is increased. Here, the "vitamin C increase cooking" menu using the steam cooking mode which keeps the temperature of the cooking chamber 12 at about 40 degreeC low temperature is demonstrated in detail.

The menu of "vitamin C increase cooking" is a steam cooking mode in which the temperature of the cooking chamber 12 is controlled to a low temperature by the control unit 30 as described above, and it is possible to cook while increasing the vitamin C contained in the food. One menu. As a food for increasing vitamin C, the effectiveness of the low temperature steam cooking mode, the basis for the increase of vitamin C, and the like will be described using 40 g of spinach which is a green-yellow vegetable.

The cooking means for increasing the vitamin C is programmed based on the data previously found by the experiment, and cooking is performed based on the basic control operation. 14 is a graph showing data obtained by experimenting with varying cooking temperatures of 40 g of spinach under saturated steam. In FIG. 14, content of the vitamin C before cooking is set to "1", and it shows how much vitamin C before cooking has increased or decreased by the start of the heating cooking after reaching each cooking temperature. In FIG. 14, the vertical axis | shaft shows the increase rate of vitamin C, and the horizontal axis | shaft shows cooking time (each time point which reached preset temperature is 0). In addition, vitamin C here is vitamin C of a reduced form.

As is also clear from the experimental data shown in FIG. 14, in the graph curves A, B, and C having the same cooking temperature as the temperature in the cooking chamber 12 at 20 ° C, 30 ° C, and 35 ° C, the content of vitamin C is "1". It does not exceed that, and it turns out that content of vitamin C tends to decrease with time. Moreover, it turns out that the graph curves F, G, H, and I which are cooking temperature 50 degreeC, 60 degreeC, 70 degreeC, and 100 degreeC also reduce content of vitamin C compared with before cooking. Among these, for example, in the case of the graph curve F having a cooking temperature of 50 ° C., when the cooking time passes about 15 minutes, the content of vitamin C reaches a maximum, but increases above the content of vitamin C before cooking. There is no case.

On the other hand, it turns out that the graph curves D and E which are cooking temperature 40 degreeC and 45 degreeC show the tendency for content of vitamin C to increase immediately after reaching a preset temperature. When the content of vitamin C gradually increased and 10 minutes after the start of cooking, the cooking temperature increased to "1.25" in the curve D of 40 ° C, and increased to "1.3" in the curve E of the cooking temperature of 45 ° C. The maximum is reached. These curves D and E show a tendency to decrease rapidly after the content of vitamin C reaches the maximum value. Thus, according to the experiment result shown in FIG. 14, it can be set as the spinach containing about 1.25 times-about 1.3 times the vitamin C compared with content of the vitamin C of spinach before cooking.

That is, according to the experimental data shown in FIG. 14, in the case of spinach, vitamin C is increased by performing heating cooking by low temperature steam in a predetermined temperature atmosphere, that is, a preferable temperature atmosphere between 40 ° C and 45 ° C. This happens. On the other hand, when a predetermined time elapses while maintaining the preferable temperature atmosphere, the phenomenon that the vitamin C contained rapidly decreases occurs.

Therefore, by setting the program of the "vitamin C increase cooking" menu based on the above experimental data, the food to be cooked is condensed and electrothermally heated at a predetermined ambient temperature by the supplied steam, and cooked when the vitamin C becomes maximum. Stops, that is, the supply of water vapor is stopped. Thereby, when the content of vitamin C becomes maximum, it becomes possible to take out the spinach which is object of cooking. Therefore, when the user eats the spinach in this state, it can be made into the spinach with which vitamin C increased compared with before cooking easily.

In addition, although detailed description is abbreviate | omitted, it is preferable to change cooking conditions slightly according to the weight of spinach. For example, when 30 g and 40 g of spinach were cooked at a cooking temperature of 40 ° C., the time until the vitamin C reached the maximum was 40 g, which tended to require a longer time than 30 g of spinach. It became clear from Therefore, the best cooking time is set by adding the data according to the weights with respect to the data shown in FIG.

In this way, cooking of greenish yellow vegetables, such as spinach, in a low temperature steam atmosphere at a predetermined temperature to apply stress to the cooking, the cooking by low temperature steam in the heating cooker 10 based on the experimental data that vitamin C increases. It can be set. Therefore, the user can increase the vitamin C contained in the food compared to before cooking, and the user can easily and simply ingest the vitamin C. In particular, when the food is green-yellow vegetables, the vitamin C of the green-yellow vegetables can be increased by heating with steam so that the temperature of the cooking chamber 12 is in the range of 40 ° C to less than 50 ° C.

In one embodiment of the present invention described above has the following effects.

The control unit 30 controls the amount of steam supplied to the cooking chamber 12 by controlling the temperature of the water storage unit 21 by the heating unit 23 when the set temperature of the cooking chamber 12 is low. Thereby, the temperature of the water storage part 21 is controlled quickly and precisely according to the set temperature of the cooking chamber 12, and the quantity of the water vapor which generate | occur | produces is also controlled precisely. Since the heat capacity of the steam is large, the temperature of the cooking chamber 12 is controlled in a stable state by controlling the amount of steam generated to control the temperature of the cooking chamber 12. In addition, by controlling the temperature of the cooking chamber 12 by the amount of water vapor having a large heat capacity, the change in temperature near the set temperature is reduced. That is, the temperature of the cooking chamber 12 decreases a slight temperature change near the set temperature, so-called ripple. Therefore, the temperature of the cooking chamber 12 can be controlled to a preset temperature precisely.

The controller 30 compares the set temperature of the cooking chamber 12 with the actual temperature of the cooking chamber 12 detected by the temperature sensor 15 and controls the temperature of the water storage unit 21 based on the difference. The temperature of the reservoir 21 is controlled by, for example, the ratio of the time for bringing the water in the reservoir 21 into a boiling state and a boiling state, that is, the boiling rate. By controlling the temperature of the reservoir 21, the amount of water vapor supplied to the cooking chamber 12, furthermore, the temperature of the cooking chamber 12 is controlled. Thereby, the temperature of the cooking chamber 12 is controlled including the influence of the heat load of the object to cook, the influence of the temperature difference between the cooking chamber 12, and external air. Therefore, the amount of steam generated and the temperature of the cooking chamber 12 can be precisely controlled.

The control part 30 changes the control temperature of the water storage part 21 at the time of the temperature rise which heats the cooking chamber 12 to the set temperature, and the temperature stable maintenance which keeps the temperature of the cooking chamber 12 stably at the set temperature, have. When the temperature rises for heating the cooking chamber 12 to the set temperature, the difference between the set temperature and the actual temperature is large. Therefore, in the case of the said temperature rise, generation | occurrence | production of water vapor is accelerated | stimulated by setting the temperature of the water storage part 21 high compared with the time of temperature stability maintenance. On the other hand, in the case of temperature stable holding | maintenance which maintains the temperature of the cooking chamber 12 stably at a preset temperature, the temperature of the water storage part 21 is controlled based on the difference between a preset temperature and an actual temperature. Therefore, when the temperature rises, the temperature of the cooking chamber 12 can be quickly raised to the set temperature, and when the temperature is kept stable, the temperature can be strictly controlled to the set temperature.

In addition, the control part 30 may control the quantity of water stored in the water storage part 21 according to the set temperature, and may control the amount of water vapor generated from the water storage part 21. In this case, when the set temperature is high, or when the difference between the set temperature and the actual temperature is large, the amount of water stored in the reservoir 21 and the area of the evaporation surface thereof are increased. As a result, a large amount of water vapor is generated. As a result, when the difference between the set temperature and the actual temperature is large as in the case of the temperature rise, the temperature of the cooking chamber 12 rises rapidly by a large amount of water vapor. On the other hand, when the set temperature is low or when the difference between the set temperature and the actual temperature is small, the amount of water stored in the reservoir 21 and the area of the evaporation surface thereof are reduced. As a result, a small amount of water vapor is generated, and the temperature change of the reservoir 21 is accelerated. As a result, when the difference between the set temperature and the actual temperature is small as in the case of maintaining temperature stability, the change in the amount of generation of water vapor accompanying the temperature change of the water storage part 21 becomes rapid, and the responsiveness of the temperature control of the cooking chamber 12 is improved. Is improved. Therefore, it is possible to achieve both the rapid rise of the temperature of the cooking chamber 12 and the precise temperature control in which the ripple in the vicinity of the set temperature is reduced.

The water supplied from the water supply tank 26 to the reservoir 21 is preheated by the preheater 25. The controller 30 controls the temperature of the water heated by the preheater 25 based on the set temperature of the cooking chamber 12 or the difference between the set temperature and the actual temperature. As a result, the water supplied to the reservoir 21 is heated to a temperature substantially equal to that of the reservoir 21. Therefore, even if it is supplied to the water storage part 21, the change of the temperature of the water storage part 21 is reduced, and the water storage part 21 maintains a stable temperature state regardless of water supply. Therefore, the temperature of the reservoir 21, the amount of steam generated, and the temperature of the cooking chamber 12 can be precisely controlled.

In addition, the control part 30 supplies the water of normal temperature to the water storage part 21 from the time of temperature rise until the temperature stability maintenance. When the transition from the temperature rise to the temperature stable maintenance time, the change in the temperature of the reservoir 21 becomes large. That is, as described above, a large amount of water is maintained at a high temperature in the reservoir 21 when the temperature rises, whereas a small amount of water is kept at a relatively low temperature in the reservoir 21 when the temperature is stable. Therefore, when transitioning from the temperature rise to the temperature stable maintenance time, by supplying water at normal temperature to the water storage part 21, the temperature of the water storage part 21 rapidly falls to the temperature required for temperature stability maintenance. At this time, the control part 30 stops heating of the water by the preheating part 25. FIG. Therefore, when the transition from the temperature rise to the temperature stable maintenance time, the temperature of the reservoir 21 can be precisely controlled.

In the present embodiment, the housing 11 forming the cooking chamber 12 may be cooled by the cooling fan 16 from the outside. Thereby, the temperature of the cooking chamber 12 tends to fall, and more water vapor can be supplied to the cooking chamber 12. In particular, when maintaining the temperature of the cooking chamber 12 near the room temperature of about 40 ° C., for example, when executing a vitamin C increased cooking menu, the temperature of the cooking chamber 12 is set only by supplying some water vapor. Reaches the temperature. Therefore, more water vapor can be supplied to the cooking chamber 12 by cooling the housing 11 and lowering the temperature of the cooking chamber 12.

(Variation)

In the above-described embodiment, the steam supply device for generating steam may be modified as described below. In addition, the same code | symbol is attached | subjected to the same structure part as the said Example.

In the modification shown in FIG. 15, the steam supply apparatus 20 which produces | generates water vapor is provided in the exterior of the housing 11. As shown in FIG. The steam supply device 20 supplies water vapor generated in the reservoir 21 to the cooking chamber 12 by an introduction fan 42 provided in the introduction pipe 41. Thereby, in the modification shown in FIG. 15, the water vapor | steam which generate | occur | produced in the water storage part 21 is introduce | transduced into the cooking chamber 12 from the side wall of the housing 11 which forms the cooking chamber 12. As shown in FIG.

In addition, as in the modification shown in FIG. 16, the steam supply device 20 that generates steam may be provided on the side wall of the housing 11 that forms the cooking chamber 12. The water storage part 21 is formed in the shape of a container by, for example, aluminum die casting or the like, and a heater of the heating part 23 is embedded. Water vapor generated in the reservoir 21 is introduced into the cooking chamber 12 from a jet port 51 provided on the side wall of the housing 11 forming the cooking chamber 12.

As mentioned above, the position of the steam supply apparatus 20 is not limited to the bottom wall side of the cooking chamber 12, but can be set to arbitrary positions.

1 is a schematic diagram showing a heating cooker according to an embodiment of the present invention,

2 is a block diagram showing the electrical configuration of the heating cooker according to an embodiment of the present invention,

3 is a diagram illustrating a relationship between a steam generation amount and a cooking temperature;

4 is a view showing the relationship between the temperature of the reservoir and the amount of steam generation;

5 is a view showing a relationship between a boiling rate per unit time and the amount of steam generated;

6 is a diagram for explaining temperature control in the vicinity of a set temperature;

FIG. 7 is a diagram for explaining temperature control at the time of temperature rise and temperature stable maintenance based on the change in boiling rate per unit time;

8 is a schematic diagram showing the structure of a steam supply device in a heating cooker according to an embodiment of the present invention,

9 is a view showing a relationship between the set temperature and the amount of water stored in the reservoir;

FIG. 10 is a diagram for explaining temperature control at the time of temperature rise and temperature stabilization based on a change in the amount of water stored in the reservoir;

11 is a diagram showing a relationship between elapsed time and actual temperature after starting heating;

FIG. 12A is a diagram showing the relationship between the elapsed time since the start of heating and the actual temperature, (B) is a diagram showing the relationship between the elapsed time since the start of heating and the amount of water vapor supplied;

13 is a schematic view of installing a cooling fan by a heating cooker according to an embodiment of the present invention;

14 is a graph based on experimental data showing a relationship between vitamin C content of spinach and various cooking temperatures;

15 is a view showing a modification of the heating cooker according to an embodiment of the present invention, and

16 is a view showing a modification of the heating cooker according to an embodiment of the present invention.

* Explanation of symbols for the main parts of the drawings

10: cooker 11: housing

12: cooking chamber 15: temperature sensor (cooking chamber temperature detection means)

16: cooling fan (cooling means) 20: steam supply device (steam supply means)

21: reservoir 22: supply

23: heating part 25: preheating part

26: water supply tank (supply part) 27: water supply pump (supply part)

28: water supply pipe (supply) 30: control unit

31: control panel

Claims (8)

A housing forming a cooking compartment for receiving and cooking food; Cooking temperature setting means for setting a cooking temperature for heating and cooking the food; Room temperature detection means for detecting an actual temperature in the food, A water storage unit for storing water, a water supply unit for supplying water to the water storage unit, and a heating unit for heating the water storage unit, generating water vapor by heating the water storage unit with the heating unit, and generating the water vapor to the cooking chamber. Water vapor supply means for supplying, and And a control unit for comparing the actual temperature detected by the room temperature detection means with the set temperature, and controlling the temperature of the water storage part so that the actual temperature becomes the set temperature according to the difference. The method of claim 1, And the control unit controls the temperature of the water storage part based on the difference between the set temperature and the actual temperature. The method of claim 1, And the control unit changes the temperature of the water storage part at the time of the temperature rise to raise the temperature of the cooking chamber to the set temperature and at the temperature stable maintenance of maintaining the temperature of the cooking chamber at the set temperature. The method of claim 1, And the control unit changes the amount of water stored in the reservoir on the basis of the set temperature. The method of claim 1, And the control unit controls the amount of water supplied from the replenishment unit to the water storage unit based on the difference between the set temperature and the actual temperature. The method of claim 1, The controller supplies water from the replenishment unit to the water storage unit between the temperature rise of raising the temperature of the cooking chamber to the set temperature and the temperature stabilization of maintaining the temperature of the cooking chamber at the set temperature. A heating cooker characterized by lowering the temperature of the reservoir. The method of claim 1, The steam supply means is provided with a preheater for heating the water supplied from the replenishment portion to the reservoir portion, And the controller controls a temperature of water heated in the preheater based on the set temperature and the difference between the set temperature and the actual temperature. The method of claim 1, And a cooling means for cooling the wall portion of the housing from the outside.

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