JP2024165546A - How to control an electric pressure cooker - Google Patents

Abstract

To provide a control method for an electric pressure cooker that can maintain a temperature of a cooking object near the boiling temperature under pressure.SOLUTION: A control method for an electric pressure cooker 10 according to the present invention includes: an inner pot 30 housed in a pressure cooker body 20; heating means 14 for heating the inner pot by changing a takt count by setting the total number of energizing times for the number obtained by dividing one cycle into multiple sections as the takt count; a temperature sensor 15 for measuring a temperature of the inner pot; and a pressure adjustment unit 70 for adjusting a pressure inside the inner pot, airtightly sealing the inside of the inner pot when the pressure inside the inner pot is equal to or lower than a predetermined value, and opening the inner pot to the atmosphere when the pressure inside the inner pot exceeds the predetermined value. The control method has a pressurizing and heating process of controlling the takt count of the heating means to adjust the heating of the inner pot when the temperature sensor detects a predetermined temperature range higher than the boiling temperature while the inner pot is airtightly sealed by the pressure adjustment unit.SELECTED DRAWING: Figure 6

Description

The present invention relates to an electric pressure cooker that can perform pressurized cooking with the inner pot pressurized, and more specifically, to an electric pressure cooker that can maintain the temperature of the food being cooked at near the boiling point under pressure.

In the cooking course of the rice cooker, the heater is controlled (temperature control) by the detection value of the temperature sensor, and when the temperature rise caused by the heater detects that the temperature is close to the boiling temperature, the heater temperature is then controlled to be close to the boiling temperature (for example, see Patent Document 1).

JP 2021-153728 A

Temperature control works well for foods with a high moisture content, such as soup. However, in electric pressure cookers that cook foods with little moisture or thick foods under pressure, the heat from the inner pot is not easily transferred to the food, while the temperature sensor's detection value is easily raised. This causes the heater to turn off early, resulting in less heat being applied to the food, which may not cook properly and may end up being undercooked.

In addition, as cooking progresses to the latter half, the food becomes soft and if it is heated too much in this state, it will fall apart. For this reason, temperature control is usually performed to lower the temperature below the boiling point in the latter half of cooking, but variations in temperature sensors can cause the food to heat more than expected, resulting in the food falling apart.

The object of the present invention is to provide a method for controlling an electric pressure cooker that can maintain the temperature of food being cooked at near the boiling point under pressure.

The method for controlling an electric pressure cooker of the present invention comprises the steps of:
An inner pot housed in the pressure cooker body;
A heating means for heating the inner pot by changing a cycle number, the total number of energizing times for the number of sections into which one cycle is divided being a cycle number;
A temperature sensor for measuring the temperature of the inner pot;
a pressure adjusting unit for adjusting the pressure in the inner pot, the pressure adjusting unit airtightly sealing the inner pot when the pressure in the inner pot is equal to or lower than a predetermined pressure, and opening the inner pot to the atmosphere when the pressure in the inner pot exceeds the predetermined pressure;
A method for controlling an electric pressure cooker comprising:
The method includes a pressurizing and heating process in which, when the temperature sensor detects a predetermined temperature range higher than the boiling temperature while the pressure regulating unit hermetically seals the inner kettle, the cycle number of the heating means is controlled to adjust the heating of the inner kettle.

The pressurizing and heating process can be controlled so that the number of cycles is gradually reduced after a predetermined time has elapsed.

The pressurizing and heating process can be controlled so that when the temperature sensor detects a temperature that exceeds the predetermined temperature range, the heating means is turned off until the temperature returns to the predetermined temperature range.

After the pressurizing and heating process, a decompression process can be performed to further reduce the cycle time or to set the cycle time to zero.

Before the pressurizing and heating process, a temperature increasing process can be performed in which the tact time of the heating means is greater than that of the pressurizing and heating process.

According to the control method for an electric pressure cooker of the present invention, by having a pressurized heating process that controls the tact number of the heating means in a predetermined temperature range higher than the boiling temperature, the food to be cooked can be maintained at a temperature close to the boiling temperature under pressure. Therefore, even if the food to be cooked is low in moisture or has a high viscosity, which is likely to cause the temperature sensor to detect a high value, it is possible to prevent the food from being undercooked. In addition, by controlling the tact number, cooking can be performed regardless of the variation in the temperature sensor. In particular, by turning off the heating means when the temperature sensor detects a temperature above the predetermined temperature range, it is possible to prevent the food from burning and the food from boiling due to forgetting to add water, etc.

FIG. 1 is a perspective view of an electric pressure cooker according to an embodiment of the present invention. FIG. 2 is a perspective view showing the electric pressure cooker with the lid open. 3 is a cross-sectional view taken along a vertical plane including line AA in FIG. 1 and seen in the direction of the arrows. 4 is a cross-sectional view taken along a vertical plane including line BB in FIG. 1 and seen in the direction of the arrows, and shows an enlarged view of the pressure detection mechanism and its vicinity. FIG. 5 is an exploded view of the pressure adjustment unit disposed in the inner lid. FIG. 6 is a timing chart showing the temperature of the temperature sensor and the on/off state of the heater according to one embodiment of the present invention. FIG. 7 is a timing chart showing the temperature of the temperature sensor and the on/off state of the heater when cooking soup, which is a food with a high moisture content. FIG. 8 is a timing chart showing the temperature of the temperature sensor and the on/off state of the heater when a hamburger steak, which is a food with a low moisture content, is being cooked. FIG. 9 is a timing chart showing the temperature of the temperature sensor and the on/off state of the heater when water was forgotten and only chicken was cooked.

Below, we will first explain the structure of one embodiment of an electric pressure cooker 10 that realizes the control method of the present invention with reference to the drawings, and then explain the control method.

As shown in Figures 1 and 2, the electric pressure cooker 10 is configured with a lid 40 attached to the top of the pressure cooker body 20 in an openable and closable manner. Inside the pressure cooker body 20, an inner pot 30 is housed as shown in Figure 2.

As shown in FIG. 1, the pressure cooker 10 is equipped with a display unit 12 that displays the cooking menu, current time, cooking completion time, etc., on the front of the pressure cooker body 20, and an operation switch 13 that performs various operations on the pressure cooker 10. The display unit 12 and the operation switch 13 can also be placed on the lid body 40, and their shapes and sizes are not limited to those of the embodiment shown in the figure. For example, the operation switch 13 is a dial with a push switch, but it may also be a touch type, etc.

As shown in FIG. 3, the rear end of the lid 40 is hinged 22 to the pressure cooker body 20. An opening/closing lever 41 for opening and closing the lid 40 is provided at the front end of the lid 40. The lid 40 is engaged with the pressure cooker body 20 by a claw 41a (see FIG. 2 and FIG. 4) that works in conjunction with the opening/closing lever 41. By pushing the opening/closing lever 41 backward, this engagement is released and the lid 40 opens as shown in FIG. 2.

As shown in FIG. 1, the top surface of the lid 40 is provided with a pressure operation button 61 for the pressure unit 60, which switches the electric pressure cooker 10 between pressure mode and non-pressurized mode, and a pressure detection pin 91 that protrudes when the inner pot 30 is pressurized, located diagonally to the left of the pressure operation button 61.

In addition, a steam hole 42 is provided on the top surface of the lid 40, behind the pressure operation button 61, to release steam from inside the inner pot 30.

The internal structure of the electric pressure cooker 10 is shown in Figure 3. The pressure cooker body 20 has a concave recess with an opening 21 on the top surface, and the inner pot 30 into which the food to be cooked is placed is removably housed. A heater 14 is installed around the inner pot 30 as a heating means for heating the inner pot 30, and by heating the inner pot 30 with the opening 21 closed with the lid 40, the food to be cooked in the inner pot 30 is cooked by heating, heated and pressurized cooking, pressurized cooking, or kept warm. The heater 14 can be a heater that heats when electricity is turned on and stops heating when electricity is turned off, such as a sheathed heater.

The pressure cooker body 20 has a temperature sensor 15 located below the inner pot 30 to measure the temperature of the bottom of the inner pot 30.

The above-mentioned display unit 12, operation switch 13, heater 14, temperature sensor 15, etc. are electrically connected to the control unit 11, which is located at appropriate positions in the pressure cooker body 20, or on the back side of the display unit 12 in FIG. 3. The control unit 11 is equipped with a microcomputer control unit, memory, timer, counter, etc. that operates the pressure cooker 10 according to a predetermined program, and controls the heater 14, etc.

Regarding the lid body 40, as shown in FIG. 2, the lid body 40 has an inner lid 44 that airtightly seals the inner pot 30. The inner lid 44 can be attached and detached to the lid body 40, and a rubber packing 45 that airtightly fits the inner pot 30 is attached to the outer periphery.

As shown in Figures 3 and 5, a pressure adjustment unit 50 is placed in the inner lid 44. The pressure adjustment unit 50 is placed above the exhaust port 46, the pressure adjustment unit hole 47, and the safety valve unit hole 48, which are opened in the center through the inner lid 44. The pressure adjustment unit 50 includes a pressurizing unit 60 including a pressurizing valve 64 that opens and closes the exhaust port 46, a pressure adjustment unit 70 placed above the pressure adjustment unit hole 47, and a safety valve unit 80 placed above the safety valve unit hole 48. Some of these are housed in casings 52 and 53 that form the air passage 43. The casings 52 and 53 are airtightly connected by a seal 54.

3, the exhaust port 46 is formed below the pressurizing operation button 61 and is connected to the steam hole 42 through an air passage 43 formed in the lid 40. The exhaust port 46 can be closed from below by a pressurizing valve 64 provided in the inner lid 44. The pressurizing valve 64 constitutes a part of the pressurizing unit 60, and is biased upward to block the exhaust port 46 by a pressurizing valve biasing spring 65. The pressurizing valve 64 also abuts against the pressurizing operation button 61 of the knock cam structure 62 that also constitutes the pressurizing unit 60. The knock cam structure 62 is equipped with a pressurizing operation button biasing means 63 that biases the pressurizing operation button 61 upward, and causes the pressurizing operation button 61 to reciprocate up and down between the upper and lower positions. A known configuration can be adopted for this knock cam structure 62, so a detailed structural description will be omitted. When the user presses the pressure application button 61, the pressure application button 61 moves downward, pushing down the pressure application valve 64 and opening the exhaust port 46. When the user presses the pressure application button 61 again as shown in FIG. 3, the pressure application button 61 moves upward, and the pressure application valve 64 is urged upward by the pressure application valve urging spring 65, closing the exhaust port 46.

That is, the pressurizing unit 60 is a unit that controls the opening and closing of the exhaust port 46 by the user's operation. When the user wishes to cook in a pressurized mode in which the inside of the inner pot 30 is pressurized, the user operates the pressurizing operation button 61 to close the exhaust port 46 with the pressurizing valve 64. When the user wishes to cook in a non-pressurized mode in which the inside of the inner pot 30 is not pressurized, the user simply operates the pressurizing operation button 61 to open the exhaust port 46. The pressurized mode and non-pressurized mode can be recognized by visually checking the state of the pressurizing operation button 61. Specifically, as shown in Figures 1 and 3, when the pressurizing operation button 61 protrudes from the lid body 40, the pressurized mode is selected, and when the pressurizing operation button 61 is flat against the lid body 40, the non-pressurized mode is selected.

The pressure adjustment unit 70 is disposed in the air passage 43 in the lid 40. The pressure adjustment unit 70 includes a pressure adjustment ball 71 shown in FIG. 5 and a pressure adjustment hole (not shown) opened directly below the pressure adjustment ball 71. The pressure adjustment ball 71 is, for example, a steel ball, and is disposed on the bowl-shaped mounting surface 72. The pressure adjustment hole is opened in the center of the bowl-shaped mounting surface 72 and opens toward the inner kettle 30 in the pressure adjustment unit hole 47. When the pressure inside the inner kettle 30 is equal to or lower than a predetermined pressure (for example, the predetermined pressure can be about 1.1 to 1.2 atmospheres), the pressure adjustment ball 71 is located in the center of the mounting surface 72 and blocks the pressure adjustment hole. When the pressure inside the inner kettle 30 exceeds the predetermined pressure, the pressure adjustment ball 71 rolls on the mounting surface 72 due to the air pressure applied from the pressure adjustment hole, opening the pressure adjustment hole and releasing the air (including steam) inside the inner kettle 30 into the air passage 43. The released air is released into the atmosphere through the steam hole 42. On the other hand, when the pressure inside the inner pot 30 falls below a certain level due to the release of air, the pressure adjustment ball 71 rolls on the mounting surface 72 and closes the pressure adjustment hole again.

The safety valve unit 80 operates when the pressure in the inner pot 30 exceeds a predetermined pressure during cooking with the pressure unit 60 in pressure mode, but the pressure in the inner pot 30 is not adjusted due to a malfunction of the pressure adjustment unit 70. The safety valve unit 80 includes a safety valve 81 and a safety valve hole (not shown) opened directly below the safety valve 81. The safety valve 81 is biased toward the safety valve hole by a safety valve biasing means 82. When the pressure in the inner pot 30 reaches the pressure at which the safety valve 81 operates, the safety valve 81 is lifted against the biasing force of the safety valve biasing means 82, and the safety valve hole opens, releasing the air in the inner pot 30.

In FIG. 5, the reference numeral 51 denotes a cover that is placed on the underside of the inner lid 44 and prevents the pressure adjustment hole and the safety valve hole from becoming clogged due to the food in the inner pot 30, such as finely chopped vegetables, entering these holes.

The pressure cooker 10 of this embodiment is equipped with a pressure determination unit 90 that allows the user to visually know whether the inner pot 30 is under pressure. The pressure determination unit 90 can be configured to include a pressure detection pin 91 (the protruding state is indicated by the symbol 91a) that protrudes upward from the lid 40 when the inner pot 30 is under pressure, as shown in FIG. 4.

The pressure detection pin 91 is arranged so that it can move up and down reciprocally within the lid 40. The pressure detection pin 91 is biased downward relative to the lid 40 by a detection pin biasing means 92, while its lower end engages with a bellows-shaped pressure detection gasket 93 with an open bottom. The inner lid 44 has a pressure detection hole 49 that communicates with the pressure detection gasket 93 when attached to the lid 40.

The biasing force of the detection pin biasing means 92 is adjusted so that the pressure detection pin 91 can move upward when the inner kettle 30 reaches a predetermined pressure (for example, 1.01 to 1.05 atm).

When the inner lid 44 is attached to the lid body 40 and the lid body 40 is closed, and pressure is applied to the inner kettle 30, the pressure in the pressure detection packing 93 also increases. As a result, the bellows portion of the pressure detection packing 93 bulges upward against the biasing force of the detection pin biasing means 92, and the pressure detection pin 91 is pushed upward and protrudes from the lid body 40 (shown by the dotted line 91a in Figure 4). In other words, when the pressure detection pin 91 protrudes from the lid body 40, the user can visually confirm that there is high pressure inside the inner kettle 30.

If the lid 40 is opened with the pressure detection pin 91 protruding, the lid 40 may be opened forcefully by the compressed air, causing steam to escape or water droplets adhering to the inner lid 44 to scatter. For this reason, it is advisable to open or close the lid 40 after the pressure detection pin 91 has lowered.

<How to use the electric pressure cooker 10>
In the pressure cooker 10 configured as above, the user places the food desired to be cooked in the inner pot 30, and as shown in Fig. 2, the inner pot 30 is housed in the pressure cooker body 20. The inner lid 44 is attached to the inside of the lid body 40, and the lid body 40 is closed as shown in Fig. 1.

<Switching Operation of Pressurizing Unit 60 Between Pressurizing Mode and Non-Pressurizing Mode>
With the lid 40 closed, the pressurizing unit 60 can be switched between a pressurizing mode in which the pressurizing valve 64 closes the exhaust port 46 and a non-pressurizing mode in which the pressurizing valve 64 opens the exhaust port 46 by operating the pressurizing operation button 61 as shown in FIG. 3. When cooking in the pressurizing mode is desired, the pressurizing operation button 61 is operated to close the exhaust port 46 with the pressurizing valve 64. In the pressurizing mode, the pressurizing operation button 61 pops out from the lid 40 as shown in FIG. 1. When cooking in the non-pressurizing mode in which the inside of the inner pot 30 is not pressurized, the pressurizing operation button 61 is operated to open the exhaust port 46. In this case, the pressurizing operation button 61 is in a flat position that does not pop out from the lid 40.

<Method of controlling electric pressure cooker 10>
In the electric pressure cooker 10, the user selects either the pressurized mode or the non-pressurized mode by operating the pressure operation button 61, selects a cooking menu corresponding to the selected mode, and controls the power supply to the heater 14 on and off in accordance with a cooking program previously stored in the control unit 11, thereby cooking.

When the user operates the pressurization operation button 61, the exhaust port 46 of the inner lid 44 is closed by the pressurization valve 64, thereby keeping the inside of the inner pot 30 airtight. When the inner pot 30 is in the pressurization mode, for example, the control unit 11 can display "Pressurizing" or the like on the display unit 12 to inform the user that it is in the pressurization mode. Also, in the pressurization mode, the control unit 11 can display cooking menus that can be pressurized on the display unit 12. For example, cooking menus that can be pressurized include cooking menus that reduce the heat of the heater 14 and prevent overflow compared to the non-pressurization mode. Hereinafter, this cooking menu will be referred to as a "pressurized heating cooking menu."

If the pressurized mode is selected by the user even though the cooking mode is non-pressurized, the display unit 12 can display a warning or caution to switch to non-pressurized mode by operating the pressure operation button 61, or cooking can be prevented from starting.

As one embodiment of the heating and pressurizing cooking of the present invention, the control method for the above-mentioned "pressurized heating and cooking menu" will be explained. FIG. 6 is a timing chart showing the relationship between the on/off state of the heater 14 and the measured value of the temperature sensor 15 when the pressure heating and cooking menu is executed. With the pressure heating and cooking menu, for example, braised pork can be cooked. In the following, specific numerical values will be appropriately shown to make the explanation easier to understand, but these numerical values are merely examples and do not limit the present invention.

The pressurized heat cooking menu has a temperature increase process, a heating and pressurizing process, and a depressurization process. The cooking time set for the pressurized heat cooking menu can be set by the user to a maximum of 2 hours (7,200 seconds), and cooking is completed when the set cooking time has elapsed. For example, if the user sets the cooking time to 90 minutes, cooking will be completed after 90 minutes.

A process time is preset for each process (only the temperature increase process 1 described below has a maximum process time), and the process time is counted by a timer in the control unit 11. In addition, an upper limit of the allowable temperature (hereinafter referred to as the "temperature control temperature") is set for each process (except for the temperature increase process 1), and if the detection value of the temperature sensor 15 exceeds the temperature control temperature while heating with the heater 14, the temperature is controlled to turn off the heater 14 until it again falls below the temperature control temperature. By setting the temperature control temperature, it is possible to prevent empty burning and burning of cooked food due to overheating of the heater 14. The temperature control temperature is the upper limit of the specified temperature range for each process in the following explanation.

In heating and pressurizing cooking, the control unit 11 regards the energization time of the heater 14 (e.g., a sheathed heater) as the number of tacts, which is the total number of times that one cycle is divided into multiple sections, and adjusts the amount of heat by increasing or decreasing this number of tacts. In a specific embodiment, one cycle is 16 seconds, and one second obtained by dividing one cycle into 16 is considered to be one tact. In other words, full energization of the heater 14 is 16 tacts (16/16 seconds), and no energization is 0 tacts (0/16 seconds).

Each process is described in detail below.

<Heating process>
As shown in FIG. 6, the temperature-raising process is a process of heating the inner pot 30 and heating the inside of the inner pot 30 to a predetermined temperature. The predetermined temperature is a temperature higher than the boiling temperature of the food to be cooked, for example, 100°C to 120°C. The temperature sensor 15 detects the temperature of the bottom surface of the inner pot 30, and the detected value is about 0°C to 20°C higher than the temperature of the food to be cooked. Therefore, by raising the temperature to a temperature higher than the boiling temperature of the food to be cooked, the food to be cooked can be raised to near the boiling temperature. This temperature-raising process can be divided into a temperature-raising process 1 (temperature-raising 1) and a temperature-raising process 2 (temperature-raising 2).

In temperature rise 1, the heater 14 is fully energized (16 tacts) or energized at a high tact close to full energization. Temperature rise 1 continues until the detection value of the temperature sensor 15 reaches a preset temperature control temperature (for example, 99°C close to the boiling temperature, dotted line C in the figure), and when the temperature control temperature C is reached, the temperature transition is controlled to transition to temperature rise 2. Note that a maximum process time is set for temperature rise 1, and in FIG. 6, temperature rise 1 is, for example, 780 seconds. That is, full electricity is applied to the heater 14 for a maximum of 780 seconds, and if the temperature control temperature C is reached during that time, the transition is made to temperature rise 2. This temperature rise 1 heats the inner pot 30 at once, and the temperature is raised to near the boiling temperature. In this embodiment, if temperature rise 1 is completed in a time shorter than 780 seconds, the remaining time can be adjusted by adding it to the pressurization process 5 described later.

In the subsequent temperature rise 2, temperature control is performed based on the process time and the specified temperature range. The process time is, for example, 300 seconds, and the temperature control temperature C (the upper limit of the specified temperature range) is 117°C. In the temperature rise 2, the number of energizing tacts to the heater 14 is set to a lower number of tacts than in the temperature rise 1, for example 10 tacts (10/16 seconds), and the amount of heat is slightly weakened. This causes the inner pot 30, which has already been heated to near the boiling temperature, to further increase in temperature. Referring to FIG. 6, it can be seen that the detection value of the temperature sensor 15 during the temperature rise 2 exceeds the boiling temperature. Note that even if the temperature rise 2 reaches the temperature control temperature C, the process does not move to the next step, and the temperature rise 2 remains in the temperature rise 2 until the specified process time has elapsed. If the detection value of the temperature sensor 15 exceeds the temperature control temperature C during the temperature rise 2, the power supply to the heater 14 is stopped. Then, when the temperature of the inner pot 30 returns to the specified temperature range, the power supply to the heater 14 is resumed. This makes it possible to prevent empty cooking and burning of the food. In addition, during the temperature rise 2, the liquid in the food boils, generating steam in the inner pot 30, and pressurizing the inner pot 30. When the inner pot 30 is pressurized, the pressure detection pin 91 protrudes from the lid 40 (symbol 91a in FIG. 4). If the air pressure in the inner pot 30 is lower than the predetermined pressure of the pressure adjustment unit 70 (for example, 1.1 atm to 1.2 atm), pressurization continues. On the other hand, when the air pressure in the inner pot 30 exceeds the predetermined pressure of the pressure adjustment unit 70, the pressure adjustment ball 71 rolls and opens the pressure adjustment hole, and the steam passes through the air passage 43 and is released into the atmosphere from the steam hole 42. Therefore, the air pressure in the inner pot 30 is maintained within a range that does not exceed the predetermined pressure during the temperature rise process. Temperature rise 2 ends when the process time has elapsed.

<Pressing step>
When the temperature rise 2 is completed, the process proceeds to the pressurization process. In the pressurization and heating process, the inner pot 30 is heated under pressure by adjusting the time for which the heater 14 is energized, i.e., the number of cycles. Heating under pressure can raise the boiling temperature of the food to be cooked, realizing cooking in a short time. For example, in the case of water, the boiling temperature at atmospheric pressure is 100°C, whereas at 1.15 atm the boiling temperature is 104°C.

In the pressurization process, the heater 14 is controlled at a smaller tact time than in the temperature increase process while performing temperature control for a specified process time. In this embodiment, the pressurization process is made up of pressurization process 1 (pressurization 1) to pressurization process 5 (pressurization 5) shown in FIG. 6, and the tact time is successively decreased from pressurization 1 to pressurization 4 (pressurization 4 and pressurization 5 are the same). Specifically, the tact time for pressurization 1 is 6 (6/16 seconds), the tact time for pressurization 2 is 5 (5/16 seconds), the tact time for pressurization 3 is 4 (4/16 seconds), and the tact time for pressurization 4 and pressurization 5 is 2 (2/16 seconds).

The controlled temperature C for the pressurization process is 117°C for pressurization 1, 113°C for pressurization 2 to pressurization 4, and 100°C for pressurization 5.

As shown in Figure 6, the set time for each step of the pressurization process is 600 seconds for pressurization 1 to pressurization 3, and 3600 seconds for pressurization 4. Pressurization 5 is 300 seconds plus the remaining time for temperature rise 1.

If the temperature sensor 15 detects a value that exceeds the regulated temperature C during the pressurizing process, power to the heater 14 is stopped. Then, when the temperature of the inner pot 30 returns to the specified temperature range, power to the heater 14 is resumed. This prevents the pot from burning dry and the food from burning. Also, if the air pressure inside the inner pot 30 during the pressurizing process exceeds the specified pressure of the pressure adjustment unit 70 (for example, 1.1 atm to 1.2 atm), the pressure adjustment unit 70 releases steam into the atmosphere, and the air pressure inside the inner pot 30 is maintained within a range that does not exceed the specified pressure.

As a result, in the pressurized heating process, the temperature of the food to be cooked is maintained close to the boiling temperature, while a pressure not exceeding a predetermined pressure is maintained. Note that a temperature close to the boiling temperature of the food to be cooked means a temperature below the boiling temperature of the food to be cooked and close to the boiling temperature, preferably in the range of about 0°C to 10°C lower than the boiling temperature, and more preferably in the range of about 0°C to 5°C lower than the boiling temperature. The boiling temperature of the food to be cooked itself varies depending on the food to be cooked, and also varies depending on the air pressure inside the inner pot 30, even for the same food.

In this invention, by maintaining the food under pressure at a temperature close to the boiling temperature, even food with low moisture content and high viscosity, which is likely to cause an increase in the detection value of the temperature sensor 15, can be cooked without being undercooked. Also, the number of tact times is increased in the order of pressure 1 to pressure 5 (pressure 4 and pressure 5 are the same), increasing the amount of heat per unit time. Also, the temperature control temperature C is set to the same or higher. As a result, sufficient heating and pressurizing cooking can be performed in the first half of the pressurizing process, and gentle heating and pressurizing cooking can be performed in the second half. This makes it possible to quickly pressurize the food in the first half to prevent it from being undercooked, and to reduce the number of tact times towards the second half to prevent the food from falling apart as it becomes gradually softer.

In the pressurized heating process, the heater 14 is controlled with a smaller cycle time than in the temperature increase process, so the inner pot 30 can be prevented from overheating. Therefore, even if there is variation in the accuracy of the temperature sensor 15, the food can be cooked stably.

During the pressurization and heating process, the pressure detection pin 91 protrudes from the lid 40 (reference number 91a in Figure 4), allowing the user to visually confirm that the inner pot 30 is in a pressurized state.

<Decompression step>
When the pressurization step is completed, the process proceeds to the depressurization step. In the depressurization step, the power supply time (cycle time) to the heater 14 is further reduced from that in the pressurization step or set to zero, and the temperature of the inner pot 30 is lowered to reduce the pressure. By reducing the pressure, the flavor can be promoted to penetrate into the food, improving the flavor of the food after cooking is completed.

In this embodiment, the decompression process is divided into decompression process 1 (decompression 1) with a tact time of 1 (1/16 seconds) and decompression process 2 (decompression 2) with a tact time of 0 (0/16 seconds). The set time for decompression 1 is, for example, 120 seconds, and the set time for decompression 2 is 300 seconds.

In decompression 1, by reducing the number of cycles compared to the pressurization step, the amount of heating is suppressed, and the temperature drops gradually, as shown in the graph in Figure 6. Since the heater 14 is operating, temperature control (temperature control temperature C: 100°C) is performed just to be safe. As the temperature drops, the air pressure in the inner pot 30 also drops. Then, by stopping the heating with decompression 2, the temperature drops further, and the air pressure in the inner pot 30 drops accordingly. The pressure detection pin 91 is embedded in the lid 40 halfway through decompression 2, allowing the user to visually confirm that decompression is complete.

By reducing the pressure inside the inner pot 30 as described above, cooking is completed and the user can open the lid 40 and immediately remove the food. Because the pressure reduction is complete, it is possible to prevent steam from gushing out and food from scattering due to air pressure when the lid 40 is opened. With a typical electric cooking pot, it is necessary to wait a long time after cooking is completed until the pressure reduction is complete, so the present invention can improve user convenience as much as possible.

After the decompression process is completed, the system may be set to switch to heat retention control, in which the heater 14 is turned on and off, based on the value detected by the temperature sensor 15, if necessary.

The above is the menu for pressure-cooked dishes.

If the cooking time set by the user for the pressurized heat cooking menu is shorter than two hours, it can be adjusted by, for example, shortening the time of pressurization 5 during the pressurization process. This is because the depressurization process cannot be eliminated. If the cooking time cannot be adjusted even if pressurization 5 is set to zero, adjustment can be made by successively shortening pressurization 4 and pressurization 3.

Figure 7 is a timing chart for a pressurized heating cooking menu in which a watery soup is cooked. The cooking time is set to 60 minutes. For the temperature rise process, the set time for temperature rise 1 (the time it takes to reach controlled temperature C for temperature rise 1) is about 420 seconds (about 7 minutes), which is about 360 seconds shorter than in Figure 6, while for the depressurization process, the set cooking time is shorter, so that for the pressure rise process, pressure rise 5 is zero and pressure rise 4 is about 1200 seconds. The number of cycles of heater 14 for each process is the same as in the table in Figure 6. Because soup has a high water content, no significant temperature change is observed even when the number of cycles is changed in the heating and pressurization process, and it can be seen that heating occurs around the boiling temperature (about 100°C).

Figure 8 is a timing chart of the pressurized heating cooking menu for cooking a hamburger steak with low moisture content. The cooking time is set to 40 minutes. For the temperature rise process, the set time for temperature rise 1 (the time to reach temperature control temperature C for temperature rise 1) is about 240 seconds (about 4 minutes), which is significantly shorter than in Figures 6 and 7 because the food contains less moisture. As a result of the shortened set cooking time, the pressurized steps are zero for pressure rise 4 and pressure rise 5, and about 240 seconds for pressure rise 3. The number of cycles of heater 14 for each process is the same as in the table in Figure 6. Hamburger steaks contain little moisture, so they can be heated all at once under temperature control, resulting in undercooking or burning. However, by controlling the heating and pressurizing process using the number of cycles, the food can be kept within a specified temperature range, and cooking can be performed while preventing undercooking or burning.

Figure 9 is a timing chart of the pressurized cooking menu when the user intends to stew chicken but forgets to add water. The set cooking time is 40 minutes. For the temperature rise process, the set time for temperature rise 1 (time to reach temperature control temperature C for temperature rise 1) is about 240 seconds (about 4 minutes), which is significantly shorter than in Figures 6 and 7 because the food contains less water. As a result of the shortened set cooking time, the pressurized steps are zero for pressure rise 4 and pressure rise 5, and about 240 seconds for pressure rise 3. The number of cycles of heater 14 in each process is the same as in the table in Figure 6. Referring to Figure 9, as a result of forgetting to add water, the temperature control temperature C is exceeded in each of the processes of temperature rise 2, pressure rise 1 to pressure rise 3, and pressure reduction 1, and heater 14 is turned off. This shows that even if water is forgotten to be added, the food is prevented from burning.

The above explanation is for the purpose of explaining the present invention, and should not be interpreted as limiting the invention described in the claims or narrowing its scope. Furthermore, the configuration of each part of the present invention is not limited to the above embodiment, and various modifications are possible within the technical scope described in the claims.

The specific configuration of the electric pressure cooker 10 is not limited to the above embodiment. For example, if the configuration has a pressure adjustment unit 70, the pressure unit 60 that switches between pressure mode and non-pressurized mode by user operation may not be required.

10 Electric pressure cooker 11 Control unit 14 Heating means (heater)
15 Temperature sensor 20 Pressure cooker body 30 Inner pot 40 Lid 50 Pressure adjustment unit 60 Pressurizing unit 70 Pressure adjustment unit 80 Safety valve unit 90 Pressurization determination unit

Claims (5)

An inner pot housed in the pressure cooker body;
A heating means for heating the inner pot by changing a cycle number, the total number of energizing times for the number of sections into which one cycle is divided being a cycle number;
A temperature sensor for measuring the temperature of the inner pot;
a pressure adjusting unit for adjusting the pressure in the inner pot, the pressure adjusting unit airtightly sealing the inner pot when the pressure in the inner pot is equal to or lower than a predetermined pressure, and opening the inner pot to the atmosphere when the pressure in the inner pot exceeds the predetermined pressure;
A method for controlling an electric pressure cooker comprising:
The pressurizing and heating process includes a pressurizing and heating process for controlling the cycle number of the heating means to adjust the heating of the inner pot when the temperature sensor detects a predetermined temperature range higher than the boiling temperature while the pressure adjusting unit airtightly seals the inner pot.
How to control an electric pressure cooker. In the pressurizing and heating process, when a predetermined time has elapsed, the tact number is controlled to be gradually decreased.
A method for controlling an electric pressure cooker according to claim 1. In the pressurizing and heating step, when the temperature sensor detects a temperature exceeding the predetermined temperature range, the heating means is turned off until the temperature returns to the predetermined temperature range.
A method for controlling an electric pressure cooker according to claim 2. After the pressurizing and heating step, a depressurizing step is provided in which the tact time is further reduced or the tact time is set to zero.
A method for controlling an electric pressure cooker according to claim 3. A temperature increasing step in which the cycle time of the heating means is greater than that of the pressurizing and heating step, is performed before the pressurizing and heating step.
A method for controlling an electric pressure cooker according to claim 4.

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