Conditioner

Abstract

To provide a cooker that can prevent a lid body from becoming difficult to separate from an upper end of a container.SOLUTION: A rice cooker according to the present invention comprises: a pot 4 for housing an object to be cooked; an inner lid 5 for covering an opening part of the pot 4 in a hermetically sealable manner; a lid clamp release button 9 for performing opening operation of the inner lid 5; a steam discharge path 18 for establishing communication between the inside and outside of the pot 4; and a pressure regulating part 17 for opening / closing the steam discharge path 18. At the time of operation of the lid clamp release button 9, the inner lid 5 is opened after the pressure regulating part 17 opens the steam discharge path 18, and the pressure regulating part 17 closes the steam discharge path 18 after the inner lid 5 is closed.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cooker that creates a decompressed and deaerated state inside a container. [Background technology]

[0002] Conventionally, as this type of cooking appliance, one equipped with a pressurizing / depressurizing device that reduces the pressure inside the inner pot using a vacuum pump has been disclosed (for example, Patent Document 1). Another known example of this type of cooking appliance is a rice cooker, and the applicant of the present application has proposed and already patented a device that is equipped with a pressure reducing means having a pressure reducing pump and a path that connects the inside of the pot with the pressure reducing pump, and that uses the pressure reducing pump to reduce the pressure inside the pot and degas the food, thereby effectively preventing the growth of bacteria inside the pot and the spoilage of rice when kept warm (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-124291 [Patent Document 2] Patent No. 4329126 Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned conventional technology has a problem in that the lid of the container is difficult to separate from the top edge of the container when the inside of the container is in a decompressed and degassed state, making it difficult to open the lid. To address this problem, the above-mentioned conventional technology uses a pressurizing and decompressing device or a decompression means to return the pressure inside the pot from the decompressed and degassed state to atmospheric pressure, but because these pressurizing and decompression devices and decompression means must be installed in the cooker, the cooker structure becomes complicated and the cooker must be made larger.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a cooking device that allows communication between the inside and outside of the container by simply opening the lid, without using a pressurizing / depressurizing device or pressure reducing means. [Means for solving the problem]

[0006] The cooking device of the present invention comprises a container for accommodating food to be cooked, a lid for hermetically covering an opening of the container, an operating unit for opening and closing the lid, a passage communicating the inside and outside of the container, and a passage opening / closing means for opening and closing the passage. the passage opening and closing means is disposed approximately at the center of the lid, and the passage opening and closing means includes a steam hole communicating with the inside of the container, a ball-shaped pressure regulating valve that opens and closes the steam hole, and a solenoid that moves the pressure regulating valve; When the operating portion is operated, the passage opening / closing means opens the passage, and then the cover opens, and the passage opening / closing means closes the passage after the cover closes. , without a vacuum pump It is characterized by: [Effects of the Invention]

[0007] According to the cooking device of the present invention, the inside and outside of the container can be communicated by opening the lid, regardless of the pressure inside the container. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic vertical cross-sectional view of a rice cooker according to an embodiment of the present invention. [Figure 2] FIG. [Figure 3] FIG. 2 is a block diagram showing the electrical configuration of the rice cooker. [Figure 4] This is a graph showing the changes over time in the detected temperature of the pot temperature sensor, the heat amount of the lid heater, the heat amount of the side heater, and the heat amount of the bottom heater during the rice cooking process and the keep-warm process. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, preferred embodiments of the cooking device of the present invention will be described with reference to the accompanying drawings. Note that common parts are designated by common reference numerals throughout the drawings.

[0010] Figures 1 to 4 show an embodiment in which the present invention is applied to a rice cooker. First, the overall configuration of the rice cooker in this embodiment will be described with reference to Figure 1. Reference numeral 1 denotes a main body with an open top, and reference numeral 2 denotes an openable lid that covers the open top of main body 1, with main body 1 and lid 2 forming the outer appearance of the rice cooker. Main body 1 has a pot housing section 3 with an open top, and when lid 2 is opened, a cylindrical pot 4 with a bottom that serves as a container for water or rice to be cooked (S) is detachably housed therein. When pot 4 is placed in main body 1 and lid 2 is closed, inner lid 5 attached to the underside of lid 2 closes the open top of pot 4.

[0011] Pot accommodating section 3 is formed as a cylinder with a bottom, leaving a space between it and the outer surface of pot 4 accommodated therein. A hot plate-type bottom heater 6 made of aluminum and a sheathed heater is disposed at the bottom of pot accommodating section 3 as heating means for heating pot 4 to cook food S. Pot 4 is placed on this bottom heater 6, which heats the outer bottom surface of pot 4. Note that instead of hot plate-type bottom heater 6, an IH (induction heating) heater may be disposed as heating means on the outer surface of pot accommodating section 3, facing the bottom surface from the lower side of pot 4. In this case, pot 4 is configured to be suspended in pot accommodating section 3.

[0012] Side heater 7, which is a cord heater, is disposed as heating means on the outer surface of pot accommodating section 3 facing the outer surface of pot 4. Side heater 7, which serves as auxiliary heating means for pot 4, is disposed opposite the upper side of pot 4, and when side heater 7 is energized, radiant heat from side heater 7 heats mainly the upper side of pot 4.

[0013] An insertion hole 3a is provided in the center of the bottom of pot accommodating section 3 and in the center of bottom heater 6, and a thermistor-type pot temperature sensor 8 is disposed in main body 1, passing through insertion hole 3a and abutting against the center of the inside of the outer bottom surface, which is the outer surface of the bottom of pot 4. Based on the temperature detected by pot temperature sensor 8, which serves as a temperature detection means for detecting the temperature of the bottom of pot 4, control means 21 (see Figure 3), which will be described later, controls the heating temperature of the bottom of pot 4 by bottom heater 6.

[0014] Pot 4 is made by pressing an aluminum plate 1 to 3 mm thick into a cylindrical shape with a bottom, and applying a fluorine coating to the inside surface. When an IH heater is used as the heating means, a heating element made of a magnetic metal plate such as ferritic stainless steel is joined to the outer surface of pot 4 from the lower side to the bottom, facing the outer surface of pot housing 3 where the IH heater is installed.

[0015] The top surface of the lid 2 is provided with a steam vent 11 that discharges steam generated from the food S in the pot 5 to the outside of the rice cooker 1. In addition, a lid clamp release button 9 is disposed in an exposed state on the front top surface of the lid 2. This lid clamp release button 9 is electrically connected to control means 21, and when the control means 21 detects that the lid clamp release button 9 has been operated, the control means 21 controls the clamp hook 15 (see Figure 3) to release its engagement with the clamp receiver (not shown). The lid clamp release button 9 is also configured to have detection means, such as a proximity sensor, that detects when the main body 1 is closed with the lid 2.

[0016] The clamp hook 15 engages and disengages the main body 1 and the lid 2 by engaging and disengaging with a clamp receiver (not shown). This engagement and disengagement with the clamp receiver is controlled by a control unit 21. Furthermore, when there is no disengagement control signal from the control unit 21, the clamp hook 15 is biased in the engagement direction by a biasing means, such as a spring. Therefore, when the lid clamp release button 9 is operated, the control unit 21 disengages the main body 1 and the lid 2 by the clamp hook 15. The hinge spring 12 (see FIG. 2 ), located at the upper rear of the main body 2, automatically opens the lid 2 around the hinge shaft 10, thereby releasing the inner lid 5 from the pot 4. Furthermore, when the lid 2 is closed to the main body 1, the biasing means biases the clamp hook 15 in the engagement direction and engages with the clamp receiver, covering the opening of the pot 5 with the inner lid 5. At this time, the detector in the lid clamp release button 9 detects that the main body 1 has been closed to the lid 2 and sends a signal to the control unit 21. Instead of the detection means for the lid clamp release button 9, a lid opening / closing detection means such as an angle sensor for detecting whether the lid 2 is open or closed may be provided near the hinge shaft 10, for example.

[0017] The lid 2, which opens and closes the upper opening of the main body 1, is provided with a thermistor-type lid temperature sensor 13 that detects the temperature of the inner lid 5, and a lid heater 14, such as a cord heater. The lid heater 14 heats the inner lid 5 and functions as lid heating means. When the inner lid 5 is attached to the lid 2, the lid temperature sensor 13 comes into contact with the top surface of the inner lid 5, and the lid heater 14 is positioned opposite the top surface of the inner lid 5. Based on the temperature detected by the lid temperature sensor 13, control means 21 controls the heating temperature of the inner lid 5 by the lid heater 14.

[0018] 2 shows a vertical cross-sectional view of the upper part of the rice cooker of this embodiment. The inner lid 5 is made of a metal material and has a disk shape with approximately the same diameter as the upper opening of the pot 4. To seal the gap between the pot 4 and the inner lid 5, it has a lid gasket 16 as an elastic member attached to the entire outer periphery of the inner lid 5. When the lid 2 is closed, the annular lid gasket 16 abuts against the upper surface and inner side surface of the upper end portion, which is the opening of the pot 4, thereby sealing the gap between the pot 4 and the inner lid 5.

[0019] Pressure adjustment unit 17 is disposed approximately in the center of inner lid 5, which forms the underside of lid 2. Pressure adjustment unit 17 includes steam hole 17a that communicates with the inside of pot 4, ball-shaped pressure adjustment valve 17b, and solenoid 17c that moves pressure adjustment valve 17b. Steam hole 17a, pressure adjustment valve 17b, and part of solenoid 17c are disposed midway along steam exhaust path 18 that connects the inside of pot 4 with steam outlet 11. When steam inside pot 4 needs to be released to the outside, solenoid 17c moves pressure adjustment valve 17b away from steam hole 17a, opening steam hole 17a that was previously blocked by pressure adjustment valve 17b and thereby opening steam exhaust path 18, maintaining the inside of pot 4 at atmospheric pressure regardless of whether pot 4 is being heated. When pressurizing or depressurizing the pot 4, the solenoid 17c moves backward, causing the pressure regulator valve 17b to move to the steam hole 17a under its own weight. This causes the pressure regulator valve 17b to close the steam hole 17a. This closes the steam exhaust path 18, sealing off all openings of the pot 4. When pressurizing the pot 4, the bottom heater 6 and side heater 7 heat the pot 4, thereby heating the food S inside the pot 4. When the internal pressure of the pot 4 reaches a predetermined value, the pressure regulator valve 17b opens the steam exhaust path 18 against its own weight, thereby maintaining the pressure inside the pot 4 at or above atmospheric pressure. Therefore, the steam exhaust path 18 functions as a passage connecting the inside and outside of the pot 4, and the pressure regulator 17 functions as a passage opening / closing device for opening and closing the steam exhaust path 18. The lid 2, which includes the inner lid 5, lid gasket 16, and pressure regulator 17, functions as a lid body that hermetically seals the opening of the pot 4. In addition, a pressure detection means such as a pressure sensor that detects the pressure inside pot 4 may be provided near pressure adjustment unit 17, for example.

[0020] Figure 3 shows the electrical configuration of the rice cooker of this embodiment. In the figure, reference numeral 21 denotes a control means incorporated inside the main body 1 or lid 2, and is composed of a control IC constituting a microcomputer, a storage means such as a readable / writable memory for storing various information and data, a timing means such as a timer, and various drive elements. The input port of the control means 21 is electrically connected to the above-mentioned pot temperature sensor 8, lid temperature sensor 13, and lid clamp release button 9, as well as an operating means 22. The output port of the control means 21 is electrically connected to the above-mentioned bottom heater 6, side heater 7, lid heater 14, solenoid 17c, and clamp hook 15, as well as a display means 23.

[0021] The operation means 22 is used to select and set cooking time, cooking menus such as rice cooking courses, and various other settings, while the display means 23 displays various information related to cooking. The user can select and set these times, cooking menus, and various other settings by operating the operation means 22 while checking the information displayed on the display means 23.

[0022] Control means 21 receives operation signals from operation means 22 and lid clamp release button 9, and detection signals from pot temperature sensor 8, lid temperature sensor 13, and lid clamp release button 9, and outputs a display control signal to display means 23 at a predetermined timing based on the timing of the built-in timer, and also outputs heating control signals to bottom heater 6, side heater 7, and lid heater 8, respectively, and output drive control signals to solenoid 17c and clamp hook 15. These functions are realized by control means 21 reading a program pre-recorded in storage means acting as a storage medium, and rice cooking control means 24 as cooking control means controls the rice cooking process, in which rice and water, which are the food to be cooked S, in pot 4 are cooked and heated to cook rice, and similarly, keep-warm control means 25 as cooking control means controls the keep-warm process, in which the rice in pot 4 is kept warm at a predetermined keep-warm temperature.

[0023] Next, the operation of the rice cooker as a cooking appliance configured as described above in the rice cooking process and the warming process will be described with reference to Fig. 4. Fig. 4 shows the change over time in the temperature t detected by the pot temperature sensor 8 and the output P of the lid heater 33 in the rice cooking process and the warming process of the rice cooker of this embodiment. L , output P of side heater 7 S , and the output P of the bottom heater 6 B The timing charts for (1) and (2) are shown in graphs and figures, respectively. In the figures, (T) indicates the period during which the steam vent 17a is closed, (H) indicates the period during which the steam vent 17a is open, and (T / H) indicates the period during which the steam vent 17a is switched between the closed state and the open state as appropriate.

[0024] To explain the operation of this embodiment during rice cooking, rice and water are placed in the pot 4 as the food to be cooked S, and then the pot is placed in the pot housing 3 of the main body 1, and the lid 2 is closed. Around the same time, when the rice cooker's power plug (not shown) is inserted into an outlet and power is applied, the rice cooker enters its initial off (standby) state, in which neither cooking nor keeping rice warm is taking place. At this time, when the detection means of the lid clamp release button 9 detects that the lid 2 has been closed, the control means 21 controls the solenoid 17c to close the steam vent 17a with the pressure regulator valve 17b, automatically cutting off communication between the inside and outside of the pot 4 without user intervention. Also, when starting cooking with a timer-programmed menu, such as rice cooking, while the timer is on standby and the cooking is waiting to start, the control means 21 controls the solenoid 17c to close the steam vent 17a with the pressure regulator valve 17b. A wide variety of bacteria float in the air, such as the outside air, and if they enter the pot 4 through the steam hole 17a, which is an opening, there is a risk that they will multiply inside the pot 4. However, in this embodiment, communication between the inside and outside of the pot 4 is blocked, thereby preventing germs such as putrefactive bacteria and food poisoning bacteria floating in the outside air from entering the pot 4 through the steam hole 17a via the steam exhaust path 18.

[0025] When the lid clamp release button 9 is operated and the control means 21 receives the operation signal, the control means 21 controls the solenoid 17c to move the pressure regulating valve 17b away from the steam hole 17a, opening the steam hole 17a. The control means 21 then controls the clamp hook 15 to disengage the main body 1 from the lid 2, opening the lid 2 and releasing the inner lid 5 from the pot 4. In this way, before the lid 2 is released, the inside of the pot 4 is connected to the outside air, releasing the reduced pressure and returning the pressure to atmospheric pressure. This makes it easier for the lid gasket 16 of the inner lid 5 to separate from the top end of the pot 4. This allows air to be exchanged between the inside of the pot 4 and the outside air, regardless of the pressure inside the pot 4, allowing the inner lid 5 attached to the underside of the lid 2 to open, and the lid 2 to be easily opened.

[0026] Thereafter, when lid 2 is closed, clamp hook 15 is urged in the engagement direction by the urging means and engages with the clamp receiver, and the detection means of lid clamp release button 9 detects that main body 1 has been closed with lid 2 and sends a signal to control means 21. When control means 21 receives this signal, it controls solenoid 17c to close steam vent 17a after a predetermined time has elapsed, for example 10 seconds. Therefore, lid 2 is not closed after steam vent 17a has been closed, and the air inside pot 4 does not create resistance and require a strong force to close lid 2, i.e., inner lid 5.

[0027] Here, for example, by operating the operating means 22 while checking the display means 23, a rice cooking course is set as a cooking menu, and then a command to start cooking is given, or when the cooking start time arrives as programmed by a timer and cooking begins, the rice cooking control means 24 carries out the cooking process in accordance with the heating pattern of the set cooking course. In this case, the rice cooking process for the food S to be cooked in the pot 4 is carried out in accordance with the heating pattern of the set rice cooking course, including (A) a soaking cooking process, (B) a boiling heating process, (C) a continuing boiling process, and (D) a steaming process.

[0028] In this embodiment, there is a possibility that the inside of pot 4 may be pressurized during cooking processes such as rice cooking, and if the inside of pot 4 is pressurized, there is a risk that the pressure inside pot 4 will cause the lid 2 to open with force. Therefore, even if lid clamp release button 9 is operated during cooking, control means 21 controls clamp hook 15 of lid clamp release button 9 so as not to release the engagement between main body 1 and lid 2. On the other hand, if it is possible to confirm, for example by pressure detection means, that the inside of pot 4 is not pressurized during cooking, when lid clamp release button 9 is operated, control means 21 may be configured to confirm that the inside of pot 4 is not pressurized, and then control clamp hook 15 of lid clamp release button 9 to release the engagement between main body 1 and lid 2.

[0029] When the rice cooking process begins, the rice cooking control means 24 outputs a heating control signal to control the on / off of the bottom heater 6 based on the temperature detected at the bottom of the pot 4 by the pot temperature sensor 8, heating the bottom of the pot 4 and raising the water temperature in the pot 5 to a predetermined temperature, for example, 35 to 60°C, thereby performing the soaking process (A) to promote water absorption by the rice. During this soaking process, the control means 21 controls the solenoid 17c to close the steam hole 17a, preventing bacteria from entering the pot 4 from the steam hole 17a via the steam exhaust path 18 and also suppressing loss of heating efficiency of the bottom heater 6.

[0030] After that, when the soaking process for a predetermined time is completed and the process moves to the next boiling heating process (B), the rice cooking control means 24 outputs a heating control signal to continuously energize the bottom heater 6 and side heater 7 and also to continuously energize the lid heater 14 during heating until boiling of the food S is detected, thereby heating the food S in the pot 4 more strongly than in the soaking cooking process. As a result, the detected temperature t detected by the pot temperature sensor 8 gradually rises, as shown in Figure 4. During this boiling heating process, the control means 21 controls the solenoid 17c to close the steam vent 17a, just as in the soaking cooking process, until boiling is detected.

[0031] In this embodiment, even when the cooking menu is other than rice cooking, the control means 21 controls the solenoid 17c to close the steam vent 17a during cooking heating from the start of cooking until the food S to be cooked boils, thereby preventing germs from entering the pot 4 through the steam vent 17a via the steam exhaust path 18 and suppressing loss of heating efficiency of the bottom heater 6 and side heater 7.

[0032] When the rice cooking control means 24 subsequently detects, via a temperature detection signal from the pot temperature sensor 8, that the detected temperature t has reached a predetermined temperature or higher, for example, 90°C or higher, it begins boiling detection to detect boiling of the food (S) under pressure. The rice cooking control means 24 then continues to continuously energize the bottom heater 6 and the side heater 7, as well as the lid heater 14, to strongly heat the food (S) inside the pot 4, while calculating the slope of the detected temperature t, i.e., how much the detected temperature t of the pot temperature sensor 8 rises over a predetermined period of time. The rice cooking control means 24 then determines that boiling has occurred when it calculates that the rise in the detected temperature t of the pot temperature sensor 8 (i.e., the temperature of the bottom of the pot 4) has fallen below a predetermined rate of temperature rise, such as 3°C or less in 120 seconds. To determine boiling, the rice cooking control means 24 may be configured to refer to the temperature detected by the lid temperature sensor (i.e., the temperature of the inner lid 5) in addition to the temperature detected by the pot temperature sensor 8.

[0033] Once rice cooking control means 24 determines that the rice has boiled, the process proceeds to the next step (C) (Continuing Boiling Step). When the process proceeds to (C) (Continuing Boiling Step), rice cooking control means 24 controls the on / off of bottom heater 6 and side heater 7 so that the temperature t detected by pot temperature sensor 8 is maintained at a predetermined temperature, such as 98°C or higher, and controls the lid heater 14 to be continuously energized so that the temperature detected by lid temperature sensor 13 is maintained at a predetermined temperature, such as 98°C or higher, thereby maintaining the boiling state of the food S to be cooked. In addition, rice cooking control means 24 controls solenoid 17c so that pressure regulator valve 17b periodically opens and closes steam exhaust path 18 to repeatedly change the pressure inside pot 4 between atmospheric pressure and a pressurized state higher than atmospheric pressure.

[0034] In this embodiment, when the cooking menu is other than rice cooking, it is possible to select whether to keep the inside of the pot 4 pressurized or at normal pressure when the food S to be cooked is boiling during cooking heating, and the control means 21 controls the solenoid 17c to close the steam hole 17a to cut off communication between the inside and outside of the pot 4 when the inside of the pot 4 is to be pressurized, and on the other hand, controls the solenoid 17c to open the steam hole 17a to open communication between the inside and outside of the pot 4 when the inside of the pot 4 is to be at normal pressure rather than pressurized.

[0035] When the rice cooking control means 24 calculates that the water inside the pot 4 has run out during the (C) continuing boiling process and that the temperature at the bottom of the pot 4 has risen at a predetermined rate, such as 0.5°C or more in 10 seconds, based on the detected temperature t of the pot temperature sensor 8, it determines that the water inside the pot 4 has run out and the pot has dried up, detects that the food inside the pot 4 is cooked, ends the (C) continuing boiling process, and moves on to the next (D) soaking process.

[0036] During the soaking step (D), the rice cooking control means 24 controls the temperature by turning the lid heater 14 on and off based on the temperature detected by the lid temperature sensor 13, preventing condensation from forming on the inner lid 5 and maintaining a temperature that will not burn the rice inside the pot 4 by continuously turning the bottom heater 6 and side heater 7 on and off for a predetermined time based on the temperature t detected by the pot temperature sensor 8. At this time, the control means 21 controls the solenoid 17c to open the steam vent 17a, actively releasing the steam and air that are gases inside the pot 4 to the outside of the rice cooker. After the predetermined time has passed, the soaking step ends, completing the rice cooking step, and the rice cooker automatically moves on to the next step, the keep-warm step.

[0037] In this embodiment, even if the cooking menu is other than rice cooking, when the food S to be cooked in the pot 4 is at a temperature equivalent to boiling temperature in the latter part of cooking or at the end of cooking, the control means 21 controls the solenoid 17c to open the steam vent 17a, opening the communication between the inside and outside of the pot 4 and actively releasing the steam and air, which are gases in the pot 4, outside the rice cooker to degas it.

[0038] When the keep-warm step begins, the keep-warm control means 25 calculates the temperature of the rice inside the pot 4 from the temperature t detected by the pot temperature sensor 8, controls the temperature of the bottom of the pot 4 based on the temperature t detected by the pot temperature sensor 8, and lowers the temperature of the rice inside the pot 4 to a keep-warm temperature of, for example, 70 to 76°C. At the same time, the lid heater 14 is controlled based on the temperature detected by the lid temperature sensor 13 to control the temperature and prevent condensation from forming on the inner lid 5. The side heaters 7 are also controlled to prevent condensation from forming on the sides of the pot 4 (E), in which the temperature lowering step (E) is performed. During the steam vent 17a is closed, and communication between the inside and outside of the pot 4 is blocked after degassing in the (D) steaming step of the rice cooking process. In this state, the temperature of the rice (food S) is lowered from near the boiling temperature to the keep-warm temperature. As a result, the temperature of gases such as steam inside the pot 4 is lowered and turns into liquid such as water, and the inside of the pot 4 enters a reduced-pressure, degassed state. When heat retention control means 25 determines based on temperature t detected by pan temperature sensor 8 that the temperature of the rice in pan 4 has dropped to the heat retention temperature, it proceeds to the next heat retention maintaining step (F).

[0039] When the process moves to the heat retention process (F), the heat retention control means 25 controls the power on / off of the bottom heater 6 based on the temperature t detected by the pot temperature sensor 8 to maintain the temperature of the food S at the heat retention temperature, and controls the lid heater 14 based on the temperature detected by the lid temperature sensor 13 to manage the temperature and prevent condensation from forming on the inner lid 5. It also controls the side heaters 7 to prevent condensation from forming on the sides of the pot 4. During the heat retention process (F), the steam vent 17a is closed, maintaining the inside of the pot 4 in a reduced pressure, deaerated state. In this way, communication between the inside and outside of the pot 4 is blocked, preventing the entry of putrefactive bacteria and food poisoning bacteria through the steam vent 17a and also preventing the entry of cold air from the outside.

[0040] The (F) warmth maintenance process may be switched to the (G) low-temperature warmth process, which maintains the temperature of the rice inside the pot 4 at a low temperature of, for example, 60 to 66°C. In this case, when the timing means detects that a predetermined time, for example, 6 hours, has passed since the rice cooking process or other cooking process was completed and the process shifted to the warmth maintenance process, the warmth maintenance control means 25 controls the power on / off of the bottom heater 6 based on the temperature t detected by the pot temperature sensor 8 to lower the temperature of the food S to a low-temperature warmth temperature of, for example, 60 to 66°C and maintains this low-temperature warmth temperature. At the same time, the lid heater 14 is controlled based on the temperature detected by the lid temperature sensor 13 to manage the temperature and prevent condensation from forming on the inner lid 5. The side heaters 7 are also controlled to prevent condensation from forming on the sides of the pot 4. This (G) low-temperature warmth process is performed, and deterioration of the warmth condition, such as yellowing of the rice inside the pot 4 or the emission of a distinctive odor, is suppressed. Also, in the (G) low temperature keeping step, as in the (F) keeping-warm step, steam vent 17a is closed, and the inside of pot 4 is maintained in a reduced pressure, deaerated state.

[0041] When the warmth control means 25 detects via the timing means that the low-temperature warming process (G) has continued for a predetermined time, such as six hours, the process transitions again to the warmth maintenance process (F). Here, the warmth control means 25 controls the solenoid 17c to open the steam vent 13a, and then controls the on / off of the bottom heater 6 based on the temperature t detected by the pot temperature sensor 8 so that the temperature of the rice becomes a predetermined temperature higher than the warmth temperature, and the steam and air in the pot 4 are released outside the rice cooker for degassing. When the warmth control means 25 subsequently determines based on the temperature t detected by the pot temperature sensor 8 that the temperature of the rice inside the pot 4 has risen by a predetermined temperature higher than the warmth temperature, it controls the solenoid 17c to close the steam vent 17a and controls the bottom heater 6, and manages the temperature of the bottom of the pot 4 based on the temperature t detected by the pot temperature sensor 8 to lower the temperature of the rice inside the pot 4 to the warmth temperature, thereby once again placing the inside of the pot 4 in a reduced-pressure, degassed state.

[0042] When the lid clamp release button 9 is operated during the warming process, the control means 21 controls the solenoid 17c to move the pressure regulator valve 17b away from the steam hole 17a, opening the steam hole 17a, just as it does when the pot is off or the timer is set. The control means 21 then controls the clamp hook 15 to release the engagement between the main body 1 and the lid 2, opening the lid 2 and releasing the inner lid 5 from the pot 4.

[0043] When the user then closes the lid 2, the biasing means biases the clamp hook 15 in the engagement direction, engaging the clamp receiver, and the detection means of the lid clamp release button 9 detects that the main body 1 has been closed by the lid 2, sending a signal to the control means 21. When the control means 21 receives this signal, it controls the solenoid 17c to close the steam vent 17a after a predetermined time, such as 10 seconds, has elapsed. The heat retention control means 25 then controls the solenoid 17c to open the steam vent 13a, and then controls the power on / off of the bottom heater 6 based on the temperature t detected by the pot temperature sensor 8. If the rice is currently in the (E) temperature drop step or the (F) heat retention maintenance step, the rice temperature is raised by a predetermined temperature above the heat retention temperature. If the rice is currently in the (G) low-temperature heat retention step, the rice temperature is raised by a predetermined temperature above the low-temperature heat retention temperature, and the steam and air in the pot 4 are released to the outside of the rice cooker for deaeration.

[0044] When the heat retention control means 25 determines based on the temperature t detected by the pot temperature sensor 8 that the temperature of the rice inside the pot 4 has risen by a predetermined temperature above the warm-keeping temperature or low-temperature warm-keeping temperature, it controls the solenoid 17c to close the steam hole 17a and also controls the bottom heater 6, managing the temperature of the bottom of the pot 4 based on the temperature t detected by the pot temperature sensor 8 to lower the temperature of the rice inside the pot 4 to the warm-keeping temperature or low-temperature warm-keeping temperature, and once again placing the inside of the pot 4 in a reduced-pressure, degassed state.

[0045] In this way, in this embodiment, the inside of pot 4 can be decompressed and deaerated without using a vacuum pump during the warming process, which simplifies the structure of the rice cooker and also enables the lid 2 to be made more compact, i.e., the rice cooker to be made more compact. Furthermore, because there is no vacuum pump, there is no driving noise when the vacuum pump is operating, and vacuum pump failure due to heat and moisture when moisture gets into the vacuum pump or steam is sucked in can be eliminated.

[0046] As described above, the rice cooker as a cooking appliance of this embodiment comprises a pot 4 as a container for containing the food to be cooked, an inner lid 5 as a lid body that sealably covers the opening of the pot 4, a lid clamp release button 9 as an operating unit for opening the inner lid 5, a steam exhaust path 18 as a passage connecting the inside and outside of the pot 4, and a pressure adjustment unit 17 as a passage opening / closing means for opening and closing the steam exhaust path 18.When the lid clamp release button 9 is operated, the pressure adjustment unit 17 opens the steam exhaust path 18, and then the inner lid 5 opens, and after the inner lid 5 is closed, the pressure adjustment unit 17 closes the steam exhaust path 18.

[0047] By configuring it in this manner, first the inside of pot 4 is connected to the outside air and the pressure is returned to atmospheric pressure, and then lid 2 is released from its latch.As a result, regardless of the pressure inside pot 4, air is exchanged between the inside of pot 4 and the outside air, and inner lid 5 attached to the underside of lid 2 can be opened.Inner lid 5 and pot 4 are kept sealed, preventing lid gasket 16 of inner lid 5 from becoming difficult to separate from the top end of pot 4, and opening the lid body allows communication between the inside and outside of the container.

[0048] In addition, the rice cooker of this embodiment further includes a bottom heater 6 as a heating means for heating the pot 4, and a pot temperature sensor 8 as a temperature detection means for detecting the temperature of the pot 4. For example, when the inner lid 5 is opened or closed during the keep-warm process, which is the process of keeping the food warm after cooking is finished, the pot 4 is heated with the steam exhaust path 18 open, and when the temperature inside the pot 4 is higher than the keep-warm temperature or low-temperature keep-warm temperature, which is the temperature during keep-warm, the pressure adjustment unit 17 closes the steam exhaust path 18 and stops heating the bottom heater 6, thereby lowering the temperature inside the pot 4 and maintaining it at the keep-warm temperature or low-temperature keep-warm temperature. Therefore, even when the inner lid 5 is opened or closed, the inside of the pot 4 can be put into a reduced-pressure degassed state, blocking communication between the inside and outside of the pot 4 and preventing the entry of putrefactive bacteria and food poisoning bacteria through the steam hole 17a, and also preventing the entry of cold air from the outside. Furthermore, since the inside of the pot 4 can be decompressed and deaerated without using a vacuum pump, the structure of the rice cooker can be simplified and the lid 2 can be made smaller, which means the rice cooker can be made smaller.

[0049] Furthermore, in the rice cooker of this embodiment, the temperature drop period for lowering the temperature inside the pot 4 is the period from when cooking of the food to be cooked is finished until the temperature inside the pot 4 reaches the keeping-warm temperature, and during the keeping-warm process the inside of the pot 4 can be put into a decompressed and deaerated state, blocking communication between the inside and outside of the pot 4 and preventing the entry of putrefactive bacteria and food poisoning bacteria through the steam vent 17a, and also preventing the entry of cold air from the outside.

[0050] In addition, in the rice cooker of this embodiment, the temperature for keeping warm in the warm process can be set to multiple values, including the temperature for maintaining warmth in the warmth maintenance process and the low-temperature temperature for keeping warm at low temperature in the low-temperature keeping process. The temperature drop period for lowering the temperature inside pot 4 is the period during the warmth keeping process when the temperature transitions from a higher warmth keeping temperature to a lower low-temperature keeping temperature. During the low-temperature keeping process in the warmth keeping process, the inside of pot 4 can be placed in a reduced-pressure degassed state, blocking communication between the inside and outside of pot 4 and preventing the entry of putrefactive bacteria and food poisoning bacteria through steam vent 17a, and also preventing the entry of cold air from the outside.

[0051] Furthermore, the rice cooker of this embodiment does not have a vacuum pump, and the inside of the pot 4 can be degassed without using a vacuum pump, which simplifies the structure of the rice cooker and allows for a more compact lid 2, i.e., a more compact rice cooker. Furthermore, because there is no vacuum pump, there is no driving noise when the vacuum pump is operating, and vacuum pump failure due to heat and moisture when moisture gets into the vacuum pump or steam is sucked in can be eliminated.

[0052] The present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in this embodiment, rice cooking using a rice cooker has been described as an example, but this rice cooker may also be used to cook dishes other than rice cooking, such as oden or stews, and may be configured to transition to a keeping-warm process after cooking, where the inside of the pot 4 is decompressed and deaerated to prevent spoilage of the food S in the pot 4 and to allow the food S to infuse with flavor and mature. The present invention may also be applied to cooking devices other than rice cookers. In this embodiment, the engagement and disengagement of the lid clamp release button 9 by the clamp hook 15 is controlled electrically by the control means 21, but the configuration may also be such that when the lid clamp release button 9 is pressed, the engagement of the clamp hook 15 of the lid clamp release button 9 is mechanically performed, disengaging the main body 1 and the lid 2, and that when the lid 2 is closed to the main body 1, the engagement of the clamp hook 15 is mechanically performed, and in this case the control means 21 may also be configured to detect that the lid clamp release button 9 has been pressed. The numerical values ​​exemplified in the embodiments are merely examples and may be changed as appropriate depending on the specifications of the rice cooker, etc. [Explanation of symbols]

[0053] 4 pots (containers) 5 Inner lid (lid body) 6 Bottom heater (heating means) 8 Pot temperature sensor (temperature detection means) 9 Lid clamp release button (operation part) 17 Pressure adjusting section (passage opening / closing means) 17a Steam vent 17b Pressure regulating valve 17c solenoid 18 Steam exhaust path (passage)

Claims

1. A container for accommodating food to be cooked; a lid that sealably covers the opening of the container; an operating unit for performing an opening operation of the lid body; a passage communicating the inside and outside of the container; a passage opening / closing means for opening and closing the passage, the passage opening and closing means is disposed approximately at the center of the lid, and the passage opening and closing means includes a steam hole communicating with the inside of the container, a ball-shaped pressure regulating valve that opens and closes the steam hole, and a solenoid that moves the pressure regulating valve; When the operating portion is operated, the passage opening / closing means opens the passage, and then the cover body is opened, After the cover is closed, the passage opening / closing means closes the passage, A cooking appliance characterized by not having a vacuum pump.

2. a heating means for heating the container; and a temperature detection means for detecting the temperature of the container. the operation unit detects the closure of the lid when the lid is closed, 2. The cooking appliance according to claim 1, wherein when the lid is opened during keeping the food warm after cooking is completed, and the operation unit subsequently detects that the lid has been closed, the container is heated with the passage open, and when the temperature inside the container is higher than the keeping temperature, which is the temperature during keeping the food warm, the passage opening / closing means closes the passage, thereby lowering the temperature inside the container and maintaining it at the keeping temperature.

3. 3. The cooking appliance according to claim 2, wherein the temperature drop period during which the temperature inside the container is lowered is a period from the end of cooking the food to the time when the temperature inside the container reaches the warm temperature.

4. A plurality of the temperature keeping temperatures can be set, 4. The cooking appliance according to claim 3, wherein the temperature drop period during which the temperature inside the container is lowered is a period during which the temperature is changed from a higher temperature to a lower temperature during the warming.

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