JP2022118246A - Cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooker capable of reliably boiling ingredients at a low temperature without prolonging a cooking time while shortening a driving time of a decompression pump.

SOLUTION: A cooker includes: a container with an opening on the top face for storing ingredients; a body for housing the container; a lid body for covering the opening of the container; a heating device for heating the container; a decompression device for decompressing the inside of the container; and a control device for controlling the heating device and the decompression device, and executing temperature raising control for heating the container and raising the temperature of the ingredients to a set temperature. The control device has a plurality of temperature raising modes that are different in the decompression start time from the start of the temperature raising control to the start of the drive of the decompression device.

SELECTED DRAWING: Figure 7

COPYRIGHT: (C)2022,JPO&INPIT

Description

TECHNICAL FIELD The present invention relates to a heating cooker that cooks food by reducing pressure and heating.

Conventionally, in a heat cooker, it is known that the contents in the container can be cooked uniformly by stirring the contents by heating the contents in the container by vacuuming the inside of the container and boiling it at a low temperature of less than 100 ° C. there is In such a heating cooker, the heat of condensation of the generated steam accelerates the temperature rise of the contents and shortens the cooking time.

For example, Patent Document 1 discloses a heating cooker that is equipped with a decompression pump, decompresses the inside of a container with a vacuum pump to create a vacuum state, and heats the container under vacuum to cook at a low temperature of less than 100°C. disclosed. The heat cooker boils the contents even in a low temperature range of less than 100° C. by reducing the pressure of the contents in the container to the saturated steam pressure.

JP 2016-189883 A

By the way, since the decompression pump makes a loud driving noise and has a short mechanical life, it is desirable to operate the decompression pump in the shortest possible driving time. However, if the decompression pump is driven for a short period of time, the contents in the container may have a higher pressure than desired due to thermal expansion due to heating, and sufficient boiling may not be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heating cooker capable of reliably boiling contents while shortening the driving time of a decompression pump.

The heating cooker of the present invention includes a container having an opening on the top surface and containing contents, a main body containing the container, a lid covering the opening of the container, and a heater for heating the container. a device, a decompression device for decompressing the inside of the container, a control device for controlling the heating device and the decompression device, and heating the container to raise the temperature of the content to a set temperature. and the control device has a plurality of temperature raising modes with different pressure reduction start times from the start of the temperature rise control to the start of driving of the pressure reducing device.

As described above, according to the heating cooker of the present invention, by having a plurality of temperature raising modes with different pressure reduction start times, pressure reduction by the pressure reduction device is started at different pressure reduction start times according to the temperature rise mode. To reliably boil contents at a low temperature without lengthening cooking time while shortening the driving time of a decompression pump.

1 is a schematic cross-sectional view showing an example of the configuration of a heating cooker according to Embodiment 1. FIG. It is a block diagram which shows an example of a structure of the heating cooker of FIG. FIG. 2 is a functional block diagram showing an example of the configuration of a control device in FIG. 1; FIG. It is a graph which shows the relationship between the temperature of a content, and a saturated vapor pressure. FIG. 4 is a schematic diagram for explaining the relationship between the temperature of the contents of the container and the pressure inside the container. FIG. 4 is a flowchart showing an example of the flow of processing by the control device of FIG. 3; FIG. 4 is a timing chart showing an example of the relationship between the temperature of the container, the pressure inside the container, and the operation timings of the heating device, the decompression pump, the electromagnetic valve, and the steam discharge valve. 10 is a timing chart showing an example of the relationship between the temperature of the container, the pressure inside the container, and the operation timings of the heating device, the decompression pump, the electromagnetic valve, and the steam discharge valve when the set temperature is the second set temperature T2; be. 5 is a timing chart showing an example of the relationship between the temperature of the container, the pressure inside the container, and the operation timings of the heating device, the decompression pump, the solenoid valve, and the steam discharge valve when the heating rate is slow. 4 is a timing chart showing an example of the relationship between the temperature of the container, the pressure inside the container, and the operation timings of the heating device, decompression pump, electromagnetic valve, and steam discharge valve when the amount of contents in the container is large. An example of the relationship between the temperature of the container, the pressure in the container, and the operation timings of the heating device, the decompression pump, the electromagnetic valve, and the steam discharge valve when the set temperature is the second set temperature T2 and the heating rate is slow. is a timing chart showing An example of the relationship between the temperature of the container, the pressure in the container, and the operation timings of the heating device, the decompression pump, the electromagnetic valve, and the steam discharge valve when the set temperature is the second set temperature T2 and the heating rate is fast. is a timing chart showing

Embodiment 1.
A heating cooker according to Embodiment 1 of the present invention will be described below. FIG. 1 is a schematic cross-sectional view showing an example of the configuration of a heating cooker 100 according to Embodiment 1. FIG. The heating cooker 100 includes a main body 1 and an outer lid 2 locked to the main body 1 so as to be openable and closable.

[Configuration of cooking device 100]
Inside the main body 1, a container housing portion 3 is internally fixed. A pot-shaped container 4 having a bottomed cylindrical shape and an open top is detachably stored in the container storage part 3 . Contents, such as foodstuffs, which are objects to be heated, are accommodated in the container 4 . A heating device 5 is provided on the outer wall of the container housing portion 3 . The heating device 5 is, for example, a heating coil 5a spirally wound in the container housing portion 3, and induction-heats the container 4 with a magnetic field generated by the supply of high-frequency current. A heating operation of the heating device 5 is controlled by the control device 50 . Note that the heating device 5 is not limited to this example, and a heater or the like that generates heat by being supplied with an electric current may be used.

A through hole is formed in the central portion of the bottom surface of the container housing portion 3, and a temperature sensor 6 is arranged in the through hole. A temperature sensor 6 is supported from below by a compression spring 7 and arranged to contact the bottom of the container 4 . A temperature sensor 6 measures the temperature of the container 4 .

A handle portion 8 is provided on the container 4 . The handle portion 8 is locked onto a holding portion (not shown) provided in the container storage portion 3 . Thereby, the container 4 is held within the main body 1 . An outwardly extending flange portion 4 a is formed around the top opening of the container 4 .

An inner lid 9 is connected to the outer lid 2 as a lid body for covering the top opening of the container 4 . A lid packing 10 as a sealing material is provided on the periphery of the inner lid 9 . The lid packing 10 is designed to ensure sealing between the inner lid 9 and the flange portion 4a and the inner wall of the container 4 when the outer lid 2 is closed.

A steam hole 11 is formed in the inner lid 9 . A steam discharge valve 12 is arranged in the steam hole 11 . The steam discharge valve 12 opens and closes under the control of the control device 50 to seal or unseal the inside of the container 4 .

A cartridge 13 is arranged downstream of the steam discharge valve 12 . The cartridge 13 has a steam outlet 14 and discharges the steam in the container 4 from the steam outlet 14 via the steam outlet valve 12 . The cartridge 13 is provided with a cartridge packing 15 for sealing the steam discharge path.

The inner lid 9 is provided with an inner lid vent hole 16 penetrating therethrough. The outer lid 2 is formed with an outer lid ventilation hole 17 that opens to the outer surface, and a communication pipe 18 that communicates between the inside and outside of the container 4 and is provided between the inner lid ventilation hole 16 and the outer lid ventilation hole 17. ing. The communicating pipe 18 is formed in a hollow shape, and a path packing 19 for hermetic connection to the inner lid vent hole 16 is arranged at the end on the inner lid vent hole 16 side.

A decompression pump 20 as a decompression device and an electromagnetic valve 21 as an opening/closing device are arranged in the communicating pipe 18 . The decompression pump 20 sucks the air inside the container 4 through the inner lid vent hole 16 and discharges the sucked air to the outside through the communicating pipe 18 and the outer lid vent hole 17, thereby decompressing the inside of the container 4. do. Driving of the decompression pump 20 is controlled by the controller 50 . The solenoid valve 21 is provided closer to the inner lid ventilation hole 16 than the pressure reducing pump 20 , and opens and closes the flow path from the inner lid ventilation hole 16 of the communicating pipe 18 to the pressure reducing pump 20 . The opening/closing operation of the solenoid valve 21 is controlled by the controller 50 .

Note that the outer lid vent 17 is preferably arranged on the side surface or the bottom surface of the outer lid 2 . This is to prevent moisture and foreign matter from entering the decompression pump 20 and to suppress failures. Further, the outer lid vent hole 17 is arranged as an exhaust hole for exhausting the air in the container 4 to the outside, but such an exhaust hole is not limited to this, and for example, the side surface or the bottom of the main body 1, etc. may be placed in

A sensor hole 22 is provided through the inner lid 9 . A lid sensor 23 as a pressure sensor and a lid sensor packing 24 are arranged on the outer lid 2 . The lid sensor 23 measures the pressure inside the container 4 through the sensor hole 22 . A lid sensor packing 24 is provided to seal the sensor hole 22 and the outer lid 2 .

Further, an operation display device 25 is installed on the main body 1 . The operation display device 25 performs input of operation instructions and the like by the user and displays operation states and the like. Note that the operation display device 25 is not limited to being installed on the main body 1, and may be installed on the outer lid 2, for example. Various functions such as operation and display on the operation display device 25 may be realized by an external device such as a smart phone.

Furthermore, the heating cooker 100 includes a control device 50 . The control device 50 controls the heating cooker 100 as a whole. In particular, in the first embodiment, the control device 50 performs the heating operation of the heating device 5, the opening and closing operation of the steam discharge valve 12, the driving of the pressure reducing pump 20, and the operation of the electromagnetic valve based on the measurement results of the temperature sensor 6 and the lid sensor 23. 21 is controlled. The control device 50 implements various functions by executing software on an arithmetic device such as a microcomputer, or is composed of hardware such as circuit devices that implement various functions. Note that the control device 50 may be provided in the main body 1 or may be provided in the outer lid 2 .

(control device 50)
FIG. 2 is a block diagram showing an example of the configuration of the heating cooker 100 of FIG. 1. As shown in FIG. As shown in FIG. 2, the control device 50 supplies a high-frequency current to the steam discharge valve 12, the decompression pump 20, the electromagnetic valve 21, the temperature sensor 6, the lid sensor 23, the operation display device 25, and the heating coil 5a. An inverter section 30 is electrically connected.

FIG. 3 is a functional block diagram showing an example of the configuration of the control device 50 of FIG. 1. As shown in FIG. As shown in FIG. 3, the control device 50 includes a temperature setting unit 51, a temperature determination unit 52, a boiling detection unit 53, a pressure setting unit 54, a pressure determination unit 55, a heating control unit 56, a pressure control unit 57 and a storage unit 58. It has

The temperature setting section 51 sets the set temperature T based on the menu input by operating the operation display device 25 and the cooking sequence stored in the storage section 58 . The temperature determination unit 52 determines the temperature of the contents of the container 4 based on the measurement results from the temperature sensor 6 . The boiling detector 53 determines whether or not the contents of the container 4 have boiled based on the measurement results from the temperature sensor 6 .

The pressure setting section 54 sets the set pressure P based on the menu input by operating the operation display device 25 and the cooking sequence stored in the storage section 58 . The pressure determination unit 55 determines the pressure inside the container 4 based on the measurement results from the lid sensor 23 .

The heating control section 56 controls the heating device 5 based on the set temperature T set by the temperature setting section 51 . Also, the heating control unit 56 controls the heating device 5 based on the determination result of the temperature determination unit 52 . Furthermore, the heating control section 56 controls the heating device 5 based on the detection result of the boiling detection section 53 .

The pressure control unit 57 controls the decompression pump 20 , the electromagnetic valve 21 and the steam discharge valve 12 based on the set pressure P set by the pressure setting unit 54 . Also, the pressure control unit 57 controls the decompression pump 20 , the electromagnetic valve 21 and the steam discharge valve 12 based on the determination result of the pressure determination unit 55 . Furthermore, the pressure control unit 57 controls the decompression pump 20 , the solenoid valve 21 and the steam discharge valve 12 based on the detection result by the boiling detection unit 53 .

The storage unit 58 stores in advance a table including cooking sequences for each menu. In response to requests from the temperature setting unit 51 and the pressure setting unit 54, the storage unit 58 reads necessary cooking sequences from the stored tables and supplies them to each.

The cooking sequence is information including a set temperature T [° C.], a set pressure P [atm], a set time for maintaining the set temperature T, a depressurization start time, and the like according to the menu. The set temperature T is a constant temperature adjusted in the temperature control process. The set temperature T is set to a temperature of 100° C. or lower. The set pressure P is a constant pressure that is adjusted in the temperature control process. The set pressure P is set to a pressure equal to or lower than the atmospheric pressure of 1.0 atm.

The depressurization start time is the time from when the temperature rising step is started until depressurization is started. The decompression start time is the time for starting decompression so that the pressure in the container 4 reaches the set pressure P at the same time when the temperature of the contents in the container 4 reaches the set temperature T, and is included in the cooking sequence. It is determined based on the time of the heating process obtained from various information. That is, the pressure reduction start time is determined according to the menu.

Such a cooking sequence is set for each menu, tabulated, and stored in advance in the storage unit 58, for example. The set conditions such as the set temperature T, the set pressure P, and the set time are not limited to being set by the cooking sequence, and may be set directly by the user, for example. Further, for example, by operating the operation display device 25 by the user, at least one or more information such as the type of food, the amount of food, or the cooking method is set, and the setting conditions are determined based on the set information. good.

[Operation of Heating Cooker 100]
Next, the operation of the heating cooker 100 having the above configuration will be described. For example, in a rice cooker, which is a heat cooker, a water absorption step of absorbing water at a temperature below the gelatinization temperature of rice (35°C to 65°C) is generally provided before a high-temperature boiling step of gelatinizing rice. there is As a result, by raising the temperature after water absorption and maintaining the boiling state, convection in the container is promoted, so that a delicious finish containing sufficient moisture can be obtained. Moreover, in the water absorption process, the amylolytic enzyme contained in the rice works, so that the sweetness can be increased and the taste can be improved.

However, when the temperature inside the container is low, boiling does not occur, so there is likely to be a difference in temperature between the bottom near the heating surface and near the water surface far from the heating surface, resulting in uneven finish. On the other hand, by boiling the contents in the container to promote convection, it is possible to reduce the unevenness of the finished rice, make the finished rice uniform after cooking, and improve the taste.

In addition, by boiling the contents in the container, even in cooking other than rice cooking, uneven heating can be reduced and the finish can be made uniform. For example, when roast beef is cooked, it is known that by cooking at a temperature of about 60° C. to 70° C., protein shrinkage is suppressed, resulting in a soft and juicy finish.

However, at low temperatures of 60-70°C boiling usually does not occur. Therefore, uneven heating tends to occur between the contents near the bottom surface that are immersed in the broth and the contents that are far from the bottom surface and are not immersed in the broth. That is, if the contents far from the bottom surface are sufficiently heated, there arises a problem that the contents near the bottom surface are boiled and collapsed. On the other hand, by decompressing the inside of the container 4 and maintaining boiling to generate steam, the part not immersed in the broth can be heated by the generated steam, so that a uniform finish can be obtained.

Therefore, the heating cooker 100 according to the first embodiment heats the container 4 and performs temperature rise control to reduce the pressure while raising the temperature of the contents, and at a vacuum, that is, a low pressure less than the atmospheric pressure, to keep the temperature constant. An operation is performed to maintain the temperature control for the set time so that the boiling is continued. By keeping the temperature constant, it is possible to cook the food in the optimum cooking time for each ingredient, and to improve the deliciousness of the food. In addition, even at a low temperature of less than 100 ° C., by maintaining the state where boiling is continued, the convection of the broth in the container 4 is promoted, so compared to when it is not boiling, the container Heating unevenness in 4 can be reduced. Since uneven heating is reduced and the contents in the container 4 are uniformly heated, the finish of the foodstuffs can be stabilized and the deliciousness can be improved.

FIG. 4 is a graph showing the relationship between the temperature of contents and the saturated vapor pressure. The graph of FIG. 4 shows the relationship between the temperature of the content and the saturated vapor pressure, that is, the pressure at which the content boils, and the boiling point. As shown in FIG. 4 , the boiling point of the content within the container 4 varies depending on the pressure within the container 4 . For example, in order to boil the water in the container 4 at 60° C., the pressure in the container 4 should be reduced to about 0.2 atmospheric pressure.

In order to boil water at 60°C, the contents must be at 60°C when the pressure inside the container 4 is reduced to 0.2 atm. Therefore, for example, after the contents in the container 4 are at room temperature and the pressure inside the container 4 is reduced to 0.2 atm, the decompression pump 20 is stopped to reduce the driving time, and the container 4 is sealed. As a result, the driving time of the decompression pump 20 can be suppressed. However, when heating is started by driving the heating device 5 after that, even if the container 4 is heated to 60° C., sufficient boiling does not occur.

This is because the pressure in the container 4 rises due to the thermal expansion of the contents due to heating, and when the contents reach 60 ° C., the pressure in the container 4 becomes saturated steam at 60 ° C., such as 0.3 atm. This is because the pressure is higher than the pressure of 0.2 atm. As shown in FIG. 4, the boiling point is about 70° C. when the saturated water vapor pressure is 0.3 atm, so when the temperature of the content is 60° C., the content does not boil.

FIG. 5 is a schematic diagram for explaining the relationship between the temperature of the contents of the container 4 and the pressure inside the container 4. As shown in FIG. As shown in FIG. 5, in this example, the pressure in the container 4 reaches the target pressure before the temperature of the contents reaches the target temperature, so the decompression pump 20 is stopped. In this case, after the decompression pump 20 is stopped, the pressure inside the container 4 rises above the target pressure due to the thermal expansion of the contents while the temperature of the contents reaches the target temperature. As a result, the boiling point of the contents rises, so even if the contents reach the target temperature, the contents do not boil because the boiling point at the time of reaching the target temperature is higher than the target temperature.

Similarly, heating and pressure reduction of the container 4 are started at the same time, and before the temperature of the contents reaches the target temperature, the pressure of the container 4 is reduced to the saturated water vapor pressure at the target temperature, and the pressure reduction pump 20 is stopped. and not enough boiling. Therefore, it becomes necessary to depressurize the container 4 again, and the driving time of the decompression pump 20 becomes longer.

Therefore, as a method for reliably boiling the contents at the target temperature, even after the pressure is reduced to the saturated vapor pressure at the target temperature, the decompression pump 20 is intermittently driven to maintain the saturated vapor pressure, and the contents are boiled. Heating to a target temperature is conceivable. However, in this case, it is necessary to drive the decompression pump 20 even after the pressure is reduced to the saturated water vapor pressure at the target temperature.

As another method for boiling the contents reliably at the target temperature, it is conceivable to heat the contents to the target temperature and then reduce the pressure to the saturated water vapor pressure at the target temperature. It takes time to depressurize the inside of the container 4 to the target pressure. Therefore, in this case, if the heating device 5 and the decompression pump 20 are simultaneously driven for at least a certain period of time, and the pressure is reduced to the saturated steam pressure when the temperature of the contents reaches the target temperature, the cooking time is lengthened. This is preferable because the driving time of the decompression pump 20 can be suppressed without having to do so.

On the other hand, even if the entire content has not reached the target temperature, the bottom surface of the container 4, which is the heating surface, is heated to a temperature higher than the target temperature, so that bubbles, which are water vapor, are formed in the container 4. Occurs within 4. This is the reason why bubbles are generated in spots at about 90° C. to 95° C., which is lower than the boiling point, at atmospheric pressure.

Therefore, when the inside of the container 4 is decompressed, for example, when the inside of the container 4 reaches the target pressure, the decompression pump 20 is stopped and the container 4 is sealed. to rapidly heat the heating surface. This causes sufficient boiling near the target temperature. If the contents are not heated with high heat, the heat is taken away by the contents, so it takes time for the heating surface to exceed the target temperature, and as a result, thermal expansion occurs and sufficient boiling cannot be obtained.

However, as described above, the heating cooker 100 according to Embodiment 1 regulates the temperature at a constant temperature while maintaining boiling in the low temperature range. Therefore, it is necessary to heat the container 4 near the target temperature so that the temperature of the container 4 does not exceed the target temperature. In this case, the temperature rise near the target temperature becomes gradual, and it takes time to reach the target temperature. Can not. Therefore, sufficient convection in the container 4 cannot be expected.

Also, by heating with high heat, convection due to boiling occurs, but the heating surface of the container 4 becomes extremely hot with respect to the boiling point. Therefore, even if convection occurs, a temperature difference occurs between the vicinity of the heating surface and the vicinity of the water surface, and the effect of suppressing uneven heating due to convection cannot be obtained.

Furthermore, in this case, the heating surface of the container 4 is heated to a temperature relatively higher than the target temperature. Therefore, even if the temperature of the container 4 is returned to the target temperature, the temperature of the contents may exceed the target temperature. Furthermore, when the heating is slowed down, the boiling inside the container 4 also becomes weak, so it becomes necessary to drive the decompression pump 20 again in order to obtain sufficient boiling. Therefore, it is not preferable to stop the decompression pump 20 before sufficient boiling occurs.

From the above, in order to boil the contents of the container 4 at the target temperature while suppressing the driving time of the decompression pump 20, , to change the timing at which the decompression pump 20 is started to be driven. In Embodiment 1, the longer the time required for the temperature raising step, the later the decompression pump 20 starts to be driven.

(basic action)
The basic operation of the heating cooker 100 according to Embodiment 1 will be described with reference to FIGS. 1 and 2. FIG. Here, a case where a heating coil 5a is used as the heating device 5 will be described as an example.

First, the user puts into the container 4 materials such as rice, meat, fish, vegetables, water and seasonings necessary for cooking any menu. After that, the container 4 is placed on the container housing portion 3 by gripping the handle portion 8 by the user, and the outer lid 2 is closed. As a result, the lid packing 10 of the inner lid 9 is brought into pressure contact with the flange portion 4a of the container 4, and the interior of the container 4 is hermetically sealed.

Next, when a user selects a menu by operating the operation display device 25 and turns on a switch (not shown), an instruction to start cooking is given to the control device 50, and cooking is started. At this time, a cooking sequence according to the selected menu is given to the control device 50 as an instruction.

When the cooking sequence is given to the control device 50, the heating coil 5a is supplied with a high frequency current from the inverter section 30 to generate a high frequency magnetic field. The surface of the container 4 facing the heating coil is magnetically coupled with the heating coil 5a by the generated high-frequency magnetic field and excited, and an eddy current is induced in the bottom surface of the container 4 . Joule heat is generated by the induced eddy current and the resistance of the container 4, and the bottom surface of the container 4 generates heat to start a temperature raising process in which the contents in the container 4 are heated. After that, when the temperature of the contents reaches the set temperature T, the inverter section 30 is controlled, and the temperature control process for maintaining the set temperature T is started.

On the other hand, the electromagnetic valve 21 is "open" at the start of cooking, and is "closed" at the start of cooking. The electromagnetic valve 21 is "opened" only when the pressure is reduced during the temperature raising process, and the pressure reducing pump 20 and the inside of the container 4 are communicated. When cooking is started, the decompression pump 20 is driven, and the air in the container 4 is discharged to the outside from the outer lid vent hole 17 via the inner lid vent hole 16 and the communicating pipe 18 . As a result, the pressure inside the container 4 is gradually lowered.

Then, when the temperature of the content reaches the boiling temperature T at the pressure P in the container 4, the content accommodated in the container 4 boils, and low-pressure low-temperature boiling starts. Note that the pressure P is lower than the atmospheric pressure of 1.0 atm.

Here, in the temperature control step, boiling of the contents generates water vapor in the container 4, and the pressure in the container 4 rises in some cases. In this case, the boiling point rises and boiling gradually stops. Therefore, the decompression pump 20 and the solenoid valve 21 are controlled, intermittent decompression is performed so that the set pressure P does not exceed the forced decompression pressure, and the pressure in the container 4 is within a certain pressure range including the set pressure P. The set pressure P is maintained so that

When the instructed set time elapses, the cooking is finished, the driving of the inverter unit 30 and the decompression pump 20 is stopped, and the heating and decompression are stopped. Also, the solenoid valve 21 is opened. By opening the electromagnetic valve 21 after the cooking is finished, the moisture sucked during cooking is discharged from the path and the food can be dried.

(cooking control)
FIG. 6 is a flow chart showing an example of the flow of processing by the control device 50 of FIG. When the control device 50 is given a cooking sequence corresponding to the menu, cooking is started and a temperature raising process is performed. In step S1, the pressure control unit 57 closes both the solenoid valve 21 and the steam discharge valve 12. As shown in FIG. Next, in step S10, the heating control unit 56 controls the heating device 5 to start heat treatment. Further, in step S20, the pressure control unit 57 determines whether or not a preset decompression start time has been reached.

As a result of the determination, if the pressure reduction start time has been reached (step S20; Yes), the pressure control unit 57 drives the pressure reduction pump 20 and "opens" the electromagnetic valve 21 to start the pressure reduction process in step S21. On the other hand, if the pressure reduction start time has not been reached (step S20; No), the process returns to step S20, and the process of step S20 is repeated until the pressure reduction start time is reached.

In step S<b>2 , the boiling detector 53 detects whether or not the contents in the container 4 have boiled based on the measurement results from the temperature sensor 6 . When it is detected that the contents in the container 4 have boiled (step S2; Yes), the process proceeds to steps S11 and S22. On the other hand, when it is detected that the contents in the container 4 have not boiled (step S2; No), the process returns to step S2, and the process of step S2 is repeated until the contents boil.

When boiling is detected in step S2, the temperature determining unit 52 sets the content in the container 4 based on the measurement result of the temperature sensor 6 and the set temperature T set by the temperature setting unit 51 in step S11. It is determined whether or not the temperature T has been reached.

When it is determined that the contents in the container 4 have reached the set temperature T (step S11; Yes), temperature control is started in step S3. If it is determined that the contents in the container 4 have not reached the set temperature T (step S11; No), the process returns to step S11, and the contents in the container 4 reach the set temperature T. The process of step S11 is repeated until the time is reached.

On the other hand, when boiling is detected in step S2, the pressure control unit 57 stops the decompression pump 20 in step S22, and closes the electromagnetic valve 21 in step S23 to seal the container 4. Then, temperature control is started in step S3.

When temperature control is started in step S3, the heating control unit 56 controls the heating device 5 so that the content in the container 4 maintains the set temperature T in step S12. In step S24, the pressure determination unit 55 also determines whether or not the pressure inside the container 4 is equal to or higher than the forced pressure reduction pressure.

If the pressure in the container 4 is equal to or higher than the forced pressure reduction pressure (step S24; Yes), the pressure control unit 57 "opens" the electromagnetic valve 21 and drives the pressure reduction pump 20 to force pressure reduction in step S25. conduct. After performing forced pressure reduction for a set time of, for example, about 5 seconds, the pressure control unit 57 "closes" the electromagnetic valve 21 and stops the pressure reduction pump 20 in step S26 to stop pressure reduction. On the other hand, if the pressure inside the container 4 is less than the forcibly reduced pressure (step S24; No), the process proceeds to step S4.

Next, in step S4, it is determined whether or not the set time has elapsed. If the set time has passed (step S4; Yes), the series of processes ends. On the other hand, if the set time has not elapsed (step S4; No), the process proceeds to steps S12 and S24 to continue temperature control.

FIG. 7 is a schematic diagram for explaining the cooking control of the heating cooker 100 according to the first embodiment. FIG. 7 shows an example of the relationship between the temperature [° C.] of the container 4 and the pressure [atm] inside the container 4, and the operation timings of the heating device 5, the decompression pump 20, the solenoid valve 21, and the steam discharge valve 12. Chart. As shown in FIG. 7, the heat cooker 100 is set with a temperature raising process and a temperature control process as processes for cooking. In this example, when cooking, the pressure inside the container 4 is reduced to the first set pressure P1, and the contents are maintained in a boiling state at the first set temperature T1.

(Temperature rising process)
The temperature raising step is a step of raising the temperature of the content in the container 4 until it boils. After starting cooking, the heating control unit 56 drives the heating device 5 so that the temperature of the container 4 measured by the temperature sensor 6 reaches the first set temperature T1 [° C.], and starts heating the container 4 . At the start of cooking, the electromagnetic valve 21 is "open", and when cooking is started, the electromagnetic valve 21 is "closed". Moreover, when cooking is started, the steam discharge valve 12 is also closed.

At time t1, when the preset decompression start time is reached, the pressure control unit 57 drives the decompression pump 20 and opens the solenoid valve 21 to start decompression in the container 4 . Then, the pressure control unit 57 continues reducing the pressure until the pressure reaches the first set pressure P1.

On the other hand, as the temperature of the container 4 measured by the temperature sensor 6 approaches the first set temperature T1, the heating control unit 56 controls the heating device 5 so that the temperature of the container 4 reaches the first set temperature T1. do. Specifically, the heating control unit 56 controls the heating device 5 so that the temperature of the container 4 gradually reaches the first set temperature T1.

At time t2, when the boiling detector 53 detects boiling, the pressure controller 57 stops the decompression pump 20 and switches the electromagnetic valve 21 from "open" to "closed" to seal the container 4. Then, the process shifts to the temperature control process. Various known methods that have been used conventionally are used to detect the boiling of the contents. Specifically, for example, a container space temperature sensor for measuring the space temperature inside the container 4 is provided, and the temperature difference between the temperature measured by the container space temperature sensor and the temperature of the container 4 measured by the temperature sensor 6 is set. When the value becomes equal to or less than the value, the boiling detection unit 53 can detect boiling.

(Temperature control process)
The temperature control step is a step of adjusting the temperature so that the temperature of the contents in the container 4 is maintained at the first set temperature T1. When the temperature of the contents reaches the first set temperature T1 and the process shifts to the temperature control process, the heating control unit 56 controls the heating device 5 so that the temperature of the contents is maintained at the first set temperature T1. Control. That is, the heating control unit 56 controls the heating device 5 so that the temperature of the container 4 measured by the temperature sensor 6 falls within a certain temperature range including the set temperature T. Here, "within a certain temperature range including the first set temperature T1" means "maintaining the first set temperature T1". When the time for the temperature control process reaches the set time, the cooking control ends.

Here, various known methods that have been conventionally used are used to determine whether or not the temperature of the contents has reached the set temperature. Specifically, for example, a method is used in which an elongated linear temperature sensor is provided in the outer lid 2 and the temperature of the contents is directly measured via a through hole provided in the inner lid 9 like the lid sensor 23. be able to. Alternatively, a method of providing a container space temperature sensor for measuring the space temperature in the container 4 and determining that the set temperature has been reached when the temperature measured by the container space temperature sensor falls below a set value may be used. good. Furthermore, a method may be used in which a timer is provided and the temperature of the container 4 measured by the temperature sensor 6 determines that the set temperature has been reached when a set time has elapsed since the temperature reached the set temperature.

As described above, in Embodiment 1, pressure reduction is started at the preset pressure reduction start time t1 during the temperature raising step, and the pressure in the container 4 is reduced at the same time when the temperature of the contents reaches the first set temperature T1 becomes the first set pressure P1. As a result, the content boils when it reaches the first set temperature T1, so that the temperature can be adjusted while the boiling is maintained in the subsequent temperature adjustment step.

[Relationship between temperature rising process time and pressure reduction start time]
Here, the temperature raising process time required for the temperature raising process varies depending on the set conditions such as the set temperature, the heating rate, and the amount of contents in the container 4 . For example, the temperature raising process time is lengthened when the set temperature is high, when the heating rate is slow, or when the amount of contents in the container 4 is large. On the other hand, the pressure reduction start time is the time from the start of the temperature raising process to the start of pressure reduction so that the pressure in the container 4 reaches the set pressure at the same time when the temperature of the contents reaches the set temperature. is. Therefore, the pressure reduction start time needs to be determined according to the set conditions such as the set temperature. Below, the depressurization start time when the heating process time is lengthened by changing the set conditions of the set temperature, the heating rate, and the amount of contents in the container 4 will be described.

(when the set temperature is high)
FIG. 8 shows the temperature [° C.] of the container 4, the pressure [atm] in the container 4, the heating device 5, the decompression pump 20, the electromagnetic valve 21, and the steam discharge when the set temperature is the second set temperature T2. 4 is a timing chart showing an example of the relationship between operation timings of the valves 12; In the example shown in FIG. 8, the second set temperature T2 is set higher than the first set temperature T1 shown in FIG. It is assumed that the heating rate based on the output of the heating device 5 and the amount of contents in the container 4 are the same as in the example of FIG.

In this case, as shown in FIG. 8, the heating rate and the amount of contents in the container 4 are the same as in the example of FIG. 7, and the second set temperature T2 is higher than the first set temperature T1. The heating process time t4 is longer than the heating process time t2 in the example of FIG. In addition, since the second set temperature T2 is higher than the first set temperature T1, the saturated water vapor pressure for boiling the contents at the second set temperature T2 is higher than the example shown in FIG. It becomes the second set pressure P2. Therefore, the decompression time for decompressing the inside of the container 4 is shorter than the example shown in FIG.

As described above, in the example shown in FIG. 8, the temperature raising process time is longer and the pressure reduction time is shorter than the example shown in FIG. also longer. Therefore, the pressure reduction start time t3 in this case is set to be longer than the pressure reduction start time t1.

(When the heating rate is slow)
FIG. 9 shows the temperature [° C.] of the container 4, the pressure [atm] in the container 4, and the operation timings of the heating device 5, the decompression pump 20, the solenoid valve 21, and the steam discharge valve 12 when the heating rate is slow. 4 is a timing chart showing an example of the relationship between . In the example shown in FIG. 9, the heating rate is set slower by setting the output of the heating device 5 lower than in the example of FIG. It is assumed that the first set temperature T1 and the amount of contents in the container 4 are the same as in the example of FIG.

In this case, as shown in FIG. 9, the first set temperature T1 and the amount of contents in the container 4 are the same as in the example of FIG. 7, and the heating rate is slower than in the example of FIG. The process time t6 is longer than the temperature raising process time t2 in the example of FIG. On the other hand, the saturated water vapor pressure for boiling the contents at the first set temperature T1 is the same as the example shown in FIG. Therefore, the decompression time for decompressing the inside of the container 4 is the same as in the example shown in FIG.

As described above, in the example shown in FIG. 9, the temperature rising process time is longer than the example in FIG. 7, and the pressure reduction time is the same. longer than Therefore, the pressure reduction start time t5 in this case is set to be longer than the pressure reduction start time t1.

(When the amount of contents is large)
FIG. 10 shows the temperature [°C] of the container 4, the pressure [atm] inside the container 4, the heating device 5, the decompression pump 20, the solenoid valve 21, and the steam discharge valve when the amount of contents in the container 4 is large. 12 is a timing chart showing an example of the relationship between operation timings of 12. FIG. In the example shown in FIG. 10, the amount of contents in the container 4 is set larger than in the example of FIG. It is assumed that the first set temperature T1 and the output of the heating device 5 are the same as in the example of FIG.

In this case, as shown in FIG. 10, the first set temperature T1 is the same as in the example of FIG. 7, the temperature raising process time t8 is longer than the temperature raising process time t2 in the example of FIG. On the other hand, the saturated water vapor pressure for boiling the contents at the first set temperature T1 is the same as the example shown in FIG. Therefore, the decompression time for decompressing the inside of the container 4 is the same as in the example shown in FIG.

As described above, in the example shown in FIG. 10, compared to the example in FIG. 7, the temperature raising process time is longer and the pressure reduction time is the same. longer than Therefore, the pressure reduction start time t7 in this case is set to be longer than the pressure reduction start time t1.

(If the set temperature is high and the heating rate is slow)
FIG. 11 shows the temperature [° C.] of the container 4, the pressure [atm] in the container 4, the heating device 5, the decompression pump 20, and the electromagnetic 4 is a timing chart showing an example of the relationship between operation timings of the valve 21 and the steam exhaust valve 12; In the example shown in FIG. 11, the second set temperature T2 is set higher than the first set temperature T1 shown in FIG. Also, the heating rate is set slower by setting the output of the heating device 5 lower than in the example of FIG. It is assumed that the amount of contents in the container 4 is the same as in the example of FIG.

In this case, as shown in FIG. 11, the amount of contents in the container 4 is the same as in the example of FIG. 7, but the second set temperature T2 is higher than the first set temperature T1 and the heating rate is 7, the temperature raising process time t10 is longer than the temperature raising process time t2 in the example of FIG. In addition, since the second set temperature T2 is higher than the first set temperature T1, the saturated water vapor pressure for boiling the contents at the second set temperature T2 is higher than the example shown in FIG. It becomes the second set pressure P2. Therefore, the decompression time for decompressing the inside of the container 4 is shorter than the example shown in FIG.

Thus, in the example shown in FIG. 11, the temperature raising process time is longer and the pressure reduction time is shorter than in the example of FIG. also longer. Therefore, the pressure reduction start time t9 in this case is set to be longer than the pressure reduction start time t1.

In the examples shown in FIGS. 8 to 11, the heating process time is longer than the example shown in FIG. 7, and the pressure reduction start time is longer in this case. Therefore, in Embodiment 1, when the temperature raising process time is long, the decompression start time is set long so that the decompression start timing is delayed. 8 to 11 and the example shown in FIG. The depressurization start time is set so as to be greater than the difference in drive time of the pump 20 .

Here, the depressurization start time for executing a pre-stored menu is determined to be the depressurization start time according to the menu pre-stored in the storage unit 58. The longer the temperature raising process time, the longer the depressurization start time. set to be long. Further, when the set temperature is directly selected by the user, or when the set temperature is set based on the information set by the user, for example, the temperature of the container 4 reaches the reference temperature corresponding to the set temperature. Depressurization may be initiated when the

Specifically, a table in which a plurality of set temperatures and the reference temperature of the container 4 at the time of starting depressurization are associated with each other is stored in advance in the storage unit 58, and when the set temperature is set by the user, , a reference temperature corresponding to the set temperature is determined by referring to the table. Then, when the temperature of the container 4 measured by the temperature sensor 6 reaches the determined reference temperature, pressure reduction is started.

Since the optimum reference temperature in this case varies greatly depending on the performance of the decompression pump 20 and the volume of the container 4, etc., the reference temperature should be set in consideration of the performance of the decompression pump 20, the volume of the container 4, and the like. good. However, in this case, the higher the set temperature, the higher the reference temperature, and the set temperature or less. That is, the reference temperature is set so that the pressure reduction is started when the temperature is lower than the set temperature. In addition, the reference temperature is obtained, for example, by using the temperature sensor 6 or the like to determine the temperature increase rate of the container 4 based on the temperature difference of the container 4 in a certain section during the temperature increase process, and using the determined temperature increase rate. may be corrected.

As described above, in the heating cooker 100 according to Embodiment 1, the control device 50 determines the pressure reduction start time according to the temperature increase time required for the temperature increase control, and controls the container 4 during the temperature increase control. The decompression pump 20 is controlled so that the internal pressure is decompressed to a set pressure below atmospheric pressure. As a result, when the temperature of the contents of the container 4 reaches the set temperature, the pressure inside the container 4 reaches the set pressure, so that the contents can be reliably boiled while shortening the driving time of the decompression pump 20. can be done.

Further, in the heat cooker 100, the decompression pump 20 is controlled such that the decompression start time when the temperature raising process time is long is longer than the decompression start time when the temperature raising process time is short. That is, when the temperature raising process time is long, the driving of the decompression pump 20 is controlled so that the decompression start timing of the decompression pump 20 is delayed. As a result, when the temperature of the contents reaches the set temperature, the pressure in the container 4 reaches the set pressure, so that the decompression pump 20 can be prevented from being driven for a long time to boil the contents. can.

Embodiment 2.
Next, Embodiment 2 of the present invention will be described. Embodiment 2 is different from Embodiment 1 in that the pressure reduction start time is changed even when the temperature rising process time is the same.

In Embodiment 1, in cooking modes with different set conditions such as the set temperature, heating rate, and amount of content in the container 4, when the temperature rising process time is different, the pressure reduction start time in the container 4 is changed. explained. On the other hand, depending on the set conditions, the heating process time may be the same even in different cooking modes. Even if the temperature rising process time is the same, it may be desirable to change the pressure reduction start time in the container 4 .

Therefore, in Embodiment 2, even when the heating process time is the same in different cooking modes, the decompression start time in the container 4 is changed. In the following description, the same reference numerals are given to the parts common to the first embodiment, and detailed description thereof will be omitted. Moreover, since the configuration and basic operation of the heating cooker 100 according to Embodiment 2 are the same as those in Embodiment 1, only the features of Embodiment 2 will be described here.

(When the set temperature is high and the heating speed is fast)
FIG. 12 shows the temperature [° C.] of the container 4 and the pressure [atm] in the container 4, the heating device 5, the decompression pump 20, and the electromagnetic 4 is a timing chart showing an example of the relationship between operation timings of the valve 21 and the steam exhaust valve 12; In the example shown in FIG. 12, the second set temperature T2 is set higher than the first set temperature T1 shown in FIG. Also, the heating rate is set faster by setting the output of the heating device 5 higher than in the example of FIG. It is assumed that the amount of contents in the container 4 is the same as in the example of FIG.

In this case, as shown in FIG. 12, the amount of contents in the container 4 is the same as in the example of FIG. 7, but the second set temperature T2 is higher than the first set temperature T1 and the heating rate is 7, the temperature raising process time t12 is equivalent to the temperature raising process time t2 in the example of FIG. In addition, since the second set temperature T2 is higher than the first set temperature T1, the saturated water vapor pressure for boiling the contents at the second set temperature T2 is higher than the example shown in FIG. It becomes the second set pressure P2. Therefore, the decompression time for decompressing the inside of the container 4 is shorter than the example shown in FIG.

As described above, in the example shown in FIG. 12, the temperature raising process time is the same as that in the example of FIG. 7, but the pressure reduction time is shorter. longer than time t1. Therefore, the pressure reduction start time t11 in this case is set to be longer than the pressure reduction start time t1.

In the example shown in FIG. 12, the pressure reduction start time is longer than in the example shown in FIG. 7 even though the temperature rising process time is the same. This is because when the set temperature is set high, the saturated water vapor pressure at the set temperature increases, thereby shortening the depressurization time. Therefore, in the second embodiment, even if the temperature raising process time is the same in different cooking modes, when the set temperature is high, the decompression start time is set long so that the decompression start timing is delayed. be. Further, in the second embodiment, the difference in the temperature raising process time between the example shown in FIG. 12 and the example shown in FIG. The pressure reduction start time is set so as to be smaller than the difference.

In addition, compared with the example shown in FIG. 7, even if the set temperature is set high, the heating process time is the same, not limited to the case where the heating rate is set to be fast. For example, when the amount of contents in the container 4 is small, the temperature rise rate is high, so even if the set temperature is set high, the temperature rise process time is the same. Therefore, in this case as well, the depressurization start time is set long, as in the example shown in FIG.

As described above, in the heating cooker 100 according to the second embodiment, the control device 50 determines the pressure reduction start time according to the set temperature, and during the temperature rising process, the pressure inside the container 4 is less than the atmospheric pressure. The decompression pump 20 is controlled to decompress to pressure. As a result, similarly to the first embodiment, it is possible to reliably boil the contents while shortening the driving time of the decompression pump 20 .

Further, in the heating cooker 100, the decompression pump 20 is controlled such that the decompression start time when the set temperature is high is longer than the decompression start time when the set temperature is low. That is, when the set temperature is high, the decompression pump 20 is controlled so that the decompression start timing of the decompression pump 20 is delayed. As a result, when the temperature of the contents in the container 4 reaches the set temperature, the pressure in the container 4 becomes the set pressure, so that the decompression pump 20 does not need to be driven for a long time to boil the contents. can be suppressed.

REFERENCE SIGNS LIST 1 main body 2 outer lid 3 container housing portion 4 container 4a flange portion 5 heating device 5a heating coil 6 temperature sensor 7 compression spring 8 handle portion 9 inner lid 10 lid packing 11 steam vent , 12 steam exhaust valve, 13 cartridge, 14 steam exhaust port, 15 cartridge packing, 16 inner lid vent, 17 outer lid vent, 18 communicating pipe, 19 path packing, 20 decompression pump, 21 solenoid valve, 22 sensor hole, 23 lid sensor, 24 lid sensor packing, 25 operation display device, 30 inverter unit, 50 control device, 51 temperature setting unit, 52 temperature determination unit, 53 boiling detection unit, 54 pressure setting unit, 55 pressure determination unit, 56 heating control Section, 57 pressure control section, 58 storage section, 100 heating cooker.

Claims (3)

a container having an opening on the upper surface and containing contents;
a main body that houses the container;
a lid covering the opening of the container;
a heating device for heating the container;
a decompression device for decompressing the inside of the container;
A control device that controls the heating device and the decompression device and performs temperature rise control to heat the container and raise the temperature of the contents to a set temperature,
The heating cooker, wherein the control device has a plurality of temperature raising modes with different pressure reduction start times from the start of the temperature rise control to the start of driving of the pressure reducing device. The heating cooker according to claim 1, wherein the pressure reduction start time is set to be longer when the amount of the contents is large than when the contents are small. further comprising an operation display device,
2. The heating cooker according to claim 1, wherein said depressurization start time is set according to a setting condition related to at least one information of food type, food amount, and cooking method set on said operation display device.

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