Electric rice cooker

Abstract

This invention provides a rice cooker that allows liquid that intrudes into the interior of the lid from the gap between the panel (equivalent to the top plate of the lid) and its adjacent components to be contained within a desired range. The rice cooker includes: a pot; a main body having a pot receiving portion capable of accommodating the pot; and a lid capable of opening and closing the pot receiving portion, the lid including: an outer cover covering the main body when the lid is closed; an outer cover having a recessed portion opening away from the main body and covering the outer cover; and an operation panel covering the recessed portion. The outer cover includes: a drain groove provided along the edge of the recessed portion and inclined in such a way as to guide liquid toward a drain hole when liquid intrudes into the recessed portion through the gap between the operation panel and the outer cover, the drain hole allowing liquid to flow out into the space defined by the outer cover and the outer cover; and a storage portion temporarily storing liquid flowing from the drain groove to the drain hole.

Description

Technical Field

[0001] This invention relates to an electric rice cooker. Background Technology

[0002] A rice cooker is known to include: a pot capable of holding food to be cooked; a main body having a pot housing section capable of holding the pot; a lid capable of opening and closing the pot housing section; a hinge mechanism connecting the lid to the main body in an openable and closable manner; and a locking mechanism locking the lid when the main body is closed in an openable and closable manner. The lid includes: an outer cover, which corresponds to a bottom plate; and a panel, which corresponds to a top plate. The locking mechanism includes a lid operating body for releasing the lock. The lid operating body passes through the inside and outside of the lid via an opening or hole provided in the panel of the lid. Pressing the lid operating body releases the lock of the locking mechanism.

[0003] If liquid, such as water, overflows from the upper surface of the lid, it will seep into the interior of the lid through tiny gaps in the openings of the lid's operating body and panel. The liquid that seeps into the lid is caught by the outer cover, which acts as the bottom plate of the lid, and drains out of the rice cooker along the outer cover. In other words, the outer cover functions as a drain tray.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2023-151879 Summary of the Invention

[0007] Sometimes the cover panel has an external surface for touch keys as an input device and a viewing window for a display device. In this case, a circuit board for mounting the input device or display device is sometimes housed within the cover. Such a cover has a small gap between itself and the panel, such as a component with a circuit board housing that houses the circuit board.

[0008] Liquids that intrude into the body of the cover from the gap between the component adjacent to the panel and the panel need to be drained to the outside in the same way as liquids that intrude into the body of the cover from the gap between the cover operating body and the opening of the cover.

[0009] However, if the drainage capacity for liquids that have seeped into the cover is insufficient, the liquid may overflow extensively and reach various electrical components located inside the cover. In particular, there is concern about electrical components whose protective retainers have been removed in order to reduce the number of components and lower costs.

[0010] Therefore, the object of the present invention is to provide a rice cooker that allows liquid that has infiltrated into the interior of the lid from the gap between the panel, which is equivalent to the top plate of the lid, and its adjacent components to remain within a desired range.

[0011] To address the aforementioned problem, the rice cooker according to embodiments of the present invention comprises: a pot capable of containing food to be cooked; a main body having a pot receiving portion capable of containing the pot; and a lid capable of opening and closing the pot receiving portion, the lid comprising: an outer cover covering the main body when the lid closes the main body; an outer cover having a recessed portion opening in a direction away from the main body and covering the outer cover; and an upper surface panel covering the recessed portion, the outer cover having: a drain groove provided along at least a portion of the edge of the recessed portion and inclined in such a way as to guide liquid toward a drain hole when liquid seeps into the recessed portion through the gap between the upper surface panel and the outer cover, the drain hole allowing the liquid to flow out into the space defined by the outer cover and the outer cover; and a storage portion temporarily storing the liquid flowing from the drain groove to the drain hole.

[0012] Invention Effects

[0013] According to the above structure, liquid that has entered the body of the cover from the gap between the panel, which is equivalent to the top plate of the cover, and its adjacent components can be retained within a desired range. Attached Figure Description

[0014] Figure 1 This is a perspective view of the rice cooker according to an embodiment of the present invention.

[0015] Figure 2 This is a longitudinal sectional view of the rice cooker according to an embodiment of the present invention.

[0016] Figure 3 This is a cross-sectional view of the inner frame and heating coil of the rice cooker involved in this embodiment.

[0017] Figure 4 This is a bottom view of the inner frame and heating coil of the rice cooker involved in this embodiment.

[0018] Figure 5 This is an exploded perspective view of the rice cooker according to this embodiment, and it shows the state after the control panel of the lid has been removed.

[0019] Figure 6 This is a top view of the outer lid of the rice cooker according to this embodiment.

[0020] Figure 7 This is an enlarged cross-sectional view of the outer cover of the rice cooker according to this embodiment, and a cross-sectional view of the surface through which the circuit board receiving recess is transversely cut in the width direction of the rice cooker.

[0021] Figure 8This is an enlarged cross-sectional view of the outer lid of the rice cooker according to this embodiment, and it is a cross-sectional view along the drain groove.

[0022] Figure 9 This is a perspective view of the inner lid unit of the rice cooker according to this embodiment, viewed from the top, i.e., the lid side.

[0023] Figure 10 This is a perspective view of the inner lid unit of the rice cooker according to this embodiment, viewed from the bottom, i.e., the main body side.

[0024] Figure 11 This is a partial bottom view of the lid of the rice cooker according to this embodiment.

[0025] Figure 12 This is a perspective view of the interior of the lid of the rice cooker according to this embodiment, and it shows the lid after the control panel and outer cover have been removed.

[0026] Figure 13 This is an enlarged cross-sectional view of the steam exhaust path and pressure regulating valve of the rice cooker involved in this embodiment.

[0027] Figure 14 This is an enlarged cross-sectional view of the safety valve of the rice cooker involved in this embodiment.

[0028] Figure 15 This is a perspective view of the gasket of the safety valve of the rice cooker according to this embodiment.

[0029] Figure 16 This is a control block diagram of the rice cooker according to an embodiment of the present invention.

[0030] Explanation of reference numerals in the attached figures

[0031] 1… Rice cooker; 21… Pot housing; 23… Main body; 25… Pot; 25a… Main component; 25b… Heating element; 26… Lid; 27… Hinge mechanism; 31… Heating coil; 31u… First coil; 31d… Second coil; 32… Flange; 35… Base plate; 36… Top frame; 37… Inner frame; 37a… Temperature sensor mounting hole; 38… Outer frame; 39… Control unit housing; 41… Vent; 42… Heating control circuit board; 43… Radiator; 45… Cooling fan; 46… Pot temperature sensor; 48… Metal plate; 51… Hinge shaft; 52… Hinge spring; 55… Outer cover; 55a… Recess; 55b… Circuit board housing recess; 56… Outer cover cover; 57… Heat sink; 58… Cover heater; 59…Inner cover unit; 61…Inner cover; 62…Cover gasket; 63…Gasket base; 65…Steam port; 66…Steam exhaust path; 67…Pressure regulating valve; 67a…Valve core; 67aa…Valve core base; 67ab…Gasket; 67b…Solenoid; 67c…Valve core drive part; 67d…Valve stem; 67da…Follower; 67db, 67dc…Cam follower surface; 67dd…Elastomer; 67e…Valve core support part; 68…Pressure reducing pump; 69…Pressure reducing hole; 70…Pressure reducing valve; 71…Cover opening operation button; 72…Cover locking mechanism; 73…Operation panel; 75…Input / output control circuit board; 76…Display part; 77…Operation part; 81…Pressure regulating hole; 81a…Thin hole; 82…High pressure exhaust hole; 85… Base; 86…Upper plate; 87…Lower plate; 88…Suction cup; 89…Connecting part; 91…Annular protrusion; 92…Recess; 95…Pressure regulating gasket; 97…Safety valve; 97a…Valve core; 97aa…Valve core base; 97ab…Gasket; 97b…Valve core retaining cylinder; 97d…Elastomer; 98…Pressure reducing gasket; 99…Inner cover mounting sensor; 101…First discharge path; 102…Second discharge path; 105…Small path; 105a…First small path; 105b…Second small path; 105c…Third small path; 105d…Fourth small path; 105e…Fifth small path; 107…First part; 107a…Arc-shaped wall; 107b…Vertical wall; 108…Second part; 108a… 108b…Cylindrical body; 109…Elastic partition wall; 109a…Deflection pipe section; 110…Inelastic partition wall; 111…First discharge port; 112…Second discharge port; 117…Valve section; 121…Frame; 122a…Cam surface; 122b…Cam surface; 122…Pressure regulating valve operating section; 123…Clamping action limiting section; 125…Anti-blocking section; 125a…Protruding end; 151…Coil drive circuit; 151u…First drive circuit; 151d…Second drive circuit; 153…Cover heater drive circuit; 155…Cover temperature sensor; 156…Cover opening and closing sensor; 157…Pressure sensor; 158…Notification section; 162…Input signal generation section; 163…Display control section;165…Condition setting unit; 167…Cooking control unit; 168…Heat preservation control unit; 201…Drain hole; 201a…Side drain hole; 201b…Front drain hole; 202…Drain groove; 202a…Narrow section drain groove; 202b…Non-narrow section drain groove; 203…Rib; 204…Storage unit; 204a…First storage unit; 204b…Second storage unit; CS…Clamp switch. Detailed Implementation

[0032] The following is for reference Figures 1 to 16 The rice cooker according to the present invention will be described. Furthermore, in the various accompanying drawings, the same or equivalent structures are labeled with the same reference numerals.

[0033] Figure 1 This is a perspective view of the rice cooker according to an embodiment of the present invention.

[0034] Figure 2 This is a longitudinal sectional view of the rice cooker according to an embodiment of the present invention.

[0035] also, Figure 1 This is a perspective view of the rice cooker 1 as seen from the upper right front of the rice cooker 1 according to this embodiment. That is, in... Figure 1 The front, right side and top surface of rice cooker 1 can be seen, while the back, left side and bottom of rice cooker 1 are hidden.

[0036] like Figure 1 and Figure 2 As shown, the rice cooker 1 according to this embodiment includes: a rectangular body 23 having an upwardly opening pot receiving portion 21; a pot 25 housed in the pot receiving portion 21; a lid 26 covering the upper surface of the body 23 and closing the pot receiving portion 21 in an openable and closable manner; a hinge mechanism 27 supporting the lid 26 to the body 23 in an openable and closable manner; and a power cord capable of connecting to an external power source, such as a commercial AC power outlet. If the lid 26 is opened upwards towards the body 23, the pot 25 can be removed from the pot receiving portion 21.

[0037] The rice cooker 1 uses a heating coil 31 to heat and cook the rice and water contained in the pot 25, and also uses the heating coil 31 to keep the cooked rice warm. The rice cooker 1 cooks the food using a cooking process that can be selected from multiple cooking processes.

[0038] Each cooking process includes cooking conditions for cooking rice into cooked rice. Cooking conditions include, for example, the type of rice, the cooking method for cooking rice into cooked rice, the firmness of the cooked rice, and the cooking time for cooking rice into cooked rice. Each cooking process includes at least two of the above cooking conditions.

[0039] Regarding each cooking process, the food being cooked in the pot 25 is pressurized and heated at a specified pressure. Each cooking process has steps set according to the brand and milling rate of the rice. These steps include, for example, a soaking process to promote water absorption by the rice added to the pot 25; a boiling heating process to raise the temperature of the food to its boiling point in a short time; a continuous boiling process to keep the food boiling; and a simmering process to maintain a high temperature to prevent the rice from burning. The rice cooker 1 may also perform a keep-warm process, either separately from or continuously relative to the cooking process, to maintain the rice in the pot 25 at a specified keep-warm temperature.

[0040] The rice cooker 1 can also perform a cooking process that heats food other than the food being cooked, contained in the pot 25, using a pre-defined heating mode. Unless otherwise stated, the food being cooked includes the food being prepared. Additionally, the rice cooker 1 can perform a cleaning process by boiling the water contained in the pot 25, using steam to float away dirt and remove odors from the interior of the rice cooker 1, particularly in hard-to-clean areas. Hereinafter, for ease of explanation, the cooking process, the food preparation process, and the cleaning process will all be collectively referred to as the "process".

[0041] The pot 25 is also called a "cauldron". The pot 25 is a bottomed container used to hold water or rice, which is the food to be cooked. The pot 25 has: a main body 25a made of highly thermally conductive aluminum; and a heating element 25b joined to the main body by covering the bottom surface from the lower outer periphery. The heating element is made of, for example, a magnetic metal plate made of ferritic stainless steel. The inner side of the pot 25 has a fluoropolymer coating. The fluoropolymer coating is formed, for example, by coating with polytetrafluoroethylene (PTFE) or perfluoroalkoxy alkane (PFA).

[0042] The pot 25 has a flange 32 that protrudes radially outward and surrounds the entire circumference of the outer peripheral surface.

[0043] The main body 23 has a rectangular shape when viewed from above. The main body 23 defines the front, back, left side, right side, and bottom of the rice cooker 1, which is located below the lid 26. The main body 23 includes: a bottom plate 35, which defines the bottom surface of the main body 23; an upper frame 36, which covers the top of the bottom plate 35 and defines a portion of the upper surface and sides of the main body 23; a bowl-shaped inner frame 37, which is integrally formed with the upper frame 36; and an outer frame 38, which defines the remaining portion of the upper surface of the main body 23.

[0044] The base plate 35, the upper frame 36, and the outer frame 38 form the external outline of the main body 23. The base plate 35 and the upper frame 36 are molded products made of synthetic resin, such as polypropylene (PP). The outer frame 38 is a molded product made of metal material, such as stainless steel.

[0045] The upper frame 36 and the inner frame 37 define the pot housing section 21. The inner frame 37 corresponds to the bottom plate of the pot housing section 21. The inner frame 37 is, for example, a machined product of aluminized steel sheet.

[0046] The pot housing 21 houses the pot 25 in a state where its upper edge contacts the lower surface of the flange 32 of the pot 25, thus suspending the pot 25 within the pot housing 21. With the pot 25 housed within the pot housing 21, the flange 32 of the pot 25 and the upper edge of the pot housing 21 are in approximately no-gap contact. However, a portion of the flange 32 of the pot 25 is not in contact. This portion defines a groove extending from the upper end of the pot housing 21, separating it from the pot housing 21. This groove creates a gap between the pot housing 21 and the flange 32 of the pot 25. This gap serves as a passage for the release of steam generated between the pot housing 21 and the pot 25 when the pot 25 is heated with moisture adhering to its outer surface.

[0047] Additionally, the main body 23 has a control chamber 39 defined between its outer contour and the pot housing 21. The outer contour of the main body 23 has a vent 41 that guides external gas into the control chamber 39. Preferably, the vent 41 is located on the bottom or side surface of the main body 23.

[0048] Furthermore, the main body 23 includes a heating control circuit board 42 housed within the control unit housing 39. The heating control circuit board 42 includes a microprocessor and a storage device that stores various calculation programs, parameters, and other digital information executed by the microprocessor. The storage device stores various settings (parameters) associated with multiple pre-set processes.

[0049] In addition, the main body 23 includes: a heat sink 43, which is mounted on a microprocessor on a heating control circuit board 42; and a cooling fan 45, which blows air onto the heat sink 43.

[0050] The heat sink 43 is made of a material with good thermal conductivity, such as aluminum. The cooling fan 45 is positioned below or to the side of the heat sink 43. The cooling performance of the combined heat sink 43 and cooling fan 45 is configured to keep the microprocessor temperature within its operating temperature range. Preferably, the cooling fan 45 and the vent 41 of the main body 23 are separated by the pot 25. This configuration facilitates product miniaturization.

[0051] Furthermore, the main body 23 includes: a heating coil 31 disposed on the outer surface of the inner frame 37; and a pot temperature sensor 46 disposed at the center of the bottom surface of the inner frame 37, which monitors the temperature of the bottom of the pot 25.

[0052] The heating coil 31 is configured to face the lower part of the outer peripheral surface and the bottom surface of the pot 25 housed in the pot housing 21. The heating coil 31 generates an alternating magnetic field to electromagnetically induction heat the heating element 25b of the pot 25.

[0053] A pot temperature sensor 46 penetrates a temperature sensor mounting hole 37a in the center of the bottom surface of the inner frame 37 and contacts the bottom surface of the pot 25. The pot temperature sensor 46 has a thermistor that monitors the temperature of the bottom of the pot 25. The temperature of the bottom of the pot 25 will be referred to as the "bottom temperature" below. The pot temperature sensor 46 is pressed against the bottom surface of the pot 25 by an elastic force. The bottom temperature detected by the pot temperature sensor 46 is specifically used for managing the heating temperature of the pot 25 based on the heating coil 31.

[0054] Furthermore, the metal plate portion 48 has a groove in a portion of the circumferential direction of the flange portion 32 of the pot 25 that does not contact the flange portion 32. This groove extends from the upper end of the pot housing portion 21, separating it from the pot housing portion 21. This groove creates a gap between the metal plate portion 48 and the flange portion 32 of the pot 25. This gap serves as a passage for the venting of steam generated between the pot housing portion 21 and the pot 25 when the pot 25 is heated with moisture adhering to its outer surface.

[0055] The hinge mechanism 27 includes: a hinge shaft 51 that connects the main body 23 and the lid 26 in a swingable manner; and a hinge spring 52 that applies a spring force to the lid 26 such that the lid 26, which closes the pot receiving portion 21, opens upward toward the main body 23 with the hinge shaft 51 as the center. The hinge shaft 51 is located near the upper part of the back surface of the main body 23.

[0056] The lid 26, viewed from above, is a rectangle that covers the main body 23. The lid 26 defines the front, back, left side, right side, and top surface of the rice cooker 1, which are located above the main body 23. The lid 26 includes: an outer cover 55 disposed on the top of the rice cooker 1; an outer cover 56 disposed between the outer cover 55 and the main body 23; a metal heat sink 57 disposed on the outer cover 56; a lid heater 58 disposed on the heat sink 57; and an inner cover unit 59 that is detachably mounted on the outer cover 56 and is detachably fitted below the heat sink 57.

[0057] The outer cover 55 covers the outer cover 56. When the cover 26 closes the main body 23, the outer cover 55 covers the outer cover 56, preventing it from being exposed in the appearance of the rice cooker 1. The outer cover 55 has: a recess 55a that opens in a direction away from the main body 23, in other words, opens towards the top of the rice cooker 1; and a circuit board receiving recess 55b disposed within the recess 55a.

[0058] The outer cover 56 covers the main body 23 when the cover 26 is closed. The outer cover 56 is a molded product of synthetic resin, such as polypropylene (PP).

[0059] The inner cover unit 59 includes: a metal inner cover 61 disposed below and in contact with the heat sink 57; a cover gasket 62 disposed on the outer periphery of the inner cover 61; and a gasket base 63 that fixes the cover gasket 62 to the inner cover 61.

[0060] The heat sink 57 and the inner cover 61 are molded products of anodized aluminum sheet or stainless steel sheet. The inner cover 61 corresponds to the bottom surface of the cover body 26. The inner cover 61 has a disc shape with a substantially the same diameter as the upper opening of the pot 25.

[0061] The cover gasket 62 is, for example, a molded product of silicone rubber or fluororubber. The cover gasket 62 is an annular seal that, when the main body 23 is closed by the cover body 26, contacts the pot 25 to close the gap between the inner cover 61 and the pot 25. The cover gasket 62 contacts the upper surface of the flange portion 32 of the pot 25 when the cover body 26 is closed.

[0062] When the lid 26, on which the inner lid unit 59 is installed, is closed, the lid gasket 62 contacts the flange 32 of the pot 25, and the inner lid unit 59 covers the upper opening of the pot 25 without gaps, sealing it so that steam generated when the pot 25 is heated will not leak between the pot 25 and the inner lid unit 59. For ease of explanation, the inside of the pot 25 closed by the inner lid unit 59 is referred to as the "pot interior space". The pot interior space is the space that contains the food being cooked, surrounded by the inner surface of the pot 25 and the bottom surface of the inner lid unit 59. In addition, for ease of explanation, the pressure in the pot interior space is referred to as the "internal pressure of the pot 25".

[0063] The cover heater 58 is, for example, a resistance wire heater. The cover heater 58 heats the inner cover 61, which is in contact with the heat sink 57, by heating the heat sink 57.

[0064] In addition, the lid 26 includes: a steam vent 65 located on the rear half of the upper surface of the lid 26, which discharges steam generated from the food being cooked in the pot 25 to the outside of the rice cooker 1; a steam discharge path 66 that guides the steam generated in the pot 25 to the steam vent 65; and a pressure regulating valve 67 that allows or cuts off the flow of gas in the steam discharge path 66.

[0065] Steam discharge path 66 connects steam port 65 and pressure regulating valve 67. Steam discharge path 66 has: an inflow-side labyrinth structure located near pressure regulating valve 67 and preventing steam from flowing into steam discharge path 66 in a straight line; and an outlet-side labyrinth structure located near steam port 65 and preventing steam from flowing into steam port 65 in a straight line.

[0066] The pressure regulating valve 67 is, for example, a solenoid valve. Opening the pressure regulating valve 67 connects the inside of the pot 25 to the outside of the rice cooker 1. At this time, the pressure regulating valve 67 opens the inside of the pot 25 to the atmosphere. The steam generated inside the pot 25 is released to the outside of the rice cooker 1 through the steam port 65. Closing the pressure regulating valve 67 cuts off the connection between the inside of the pot 25 and the outside of the rice cooker 1, restricting the entry and exit of gas through the steam exhaust path 66. At this time, the pressure regulating valve 67 seals the inside of the pot 25. The steam generated inside the pot 25 causes the internal pressure of the pot 25 to rise above atmospheric pressure. By drawing out the gas from the pot 25 while the pressure regulating valve 67 is closed, the internal pressure of the pot 25 can be reduced compared to atmospheric pressure. By opening the pressure regulating valve 67 while the internal pressure of the pot 25 is reduced, the internal pressure of the pot 25 can be restored to atmospheric pressure.

[0067] The pressure regulating valve 67 includes: a valve core 67a that permits or cuts off the flow of gas in the steam discharge path 66; and a valve core drive unit 67c, which includes a solenoid 67b that drives the valve core 67a to open and close. When releasing steam from the pot 25 to the outside of the rice cooker 1, the solenoid 67b moves the valve core 67a in one direction to permit the flow of steam in the steam discharge path 66. Conversely, when the internal pressure of the pot 25 is increased or decreased, the solenoid 67b moves the valve core 67a in the other direction to cut off the flow of steam in the steam discharge path 66. When the food being cooked in the pot 25 boils and generates steam, if the steam fills the pot 25 and causes the internal pressure of the pot 25 to exceed a predetermined value, the valve core 67a is pressed upwards by the internal pressure of the pot 25 to open the steam discharge path 66. Furthermore, if the internal pressure of the pot 25 drops below the predetermined value, the valve core 67a closes the steam discharge path 66. The internal pressure of the pot 25 is maintained above atmospheric pressure by the action of the valve core 67a.

[0068] Furthermore, the lid 26 is equipped with a pressure-reducing pump 68 that reduces pressure inside the pot 25 when the lid 26 is closed.

[0069] In addition, the cover 26 includes: a cover opening operation button 71, which is located on the front half of the upper surface of the cover 26; a cover locking mechanism 72, which locks the opening and closing of the cover 26; an operation panel 73 as an input / output device; and an input / output control circuit board 75, which controls the operation of the operation panel 73.

[0070] If the lid opening operation button 71 is operated, the lock between the lid 26 and the main body 23, which close the pot receiving part 21, is released. If the lock between the lid 26 and the main body 23 is released, the elastic force of the hinge spring 52 causes the lid 26 to open about the hinge axis 51.

[0071] The lid locking mechanism 72 locks the lid 26 closed by the main body 23. The lid locking mechanism 72 releases the lid 26 lock in conjunction with the operation of the lid opening operation button 71. Even when the internal pressure of the pot 25 is increased or decreased, the lid locking mechanism 72 prevents the lid 26 from opening even with a single downward press of the lid opening operation button 71. If the lid opening operation button 71 is pressed down with light force, the lid locking mechanism 72 activates the pressure regulating valve 67 and the pressure reducing pump 68, causing the internal pressure of the pot 25 to return to atmospheric pressure within a specified time. When the lid opening operation button 71 is pressed down again after the specified time, the lid locking mechanism 72 releases the restriction on the opening of the lid 26. The lid locking action of this lid locking mechanism 72 is controlled by the heating control circuit board 42. Detailed construction and control of the lid locking mechanism 72 can be found in, for example, in the prior art disclosed in Japanese Patent Application Publication No. 2015-171545. The lid locking mechanism 72 does not always perform the lid locking action. When the lid locking action is not performed, the lid 26 can be opened by operating the lid opening operation button 71 once.

[0072] The control panel 73 is the upper surface panel of the cover 26 and the rice cooker 1, and covers the recess 55a of the outer cover 55. The control panel 73 includes: a display unit 76 that displays various information; and an operation unit 77 that handles various operations. In addition, the display unit 76 and the operation unit 77 are substantially mounted on the input / output control circuit board 75. The control panel 73 has: a viewing window that displays the display unit 76 through a view; and keycaps, which are decorative panels that the user directly touches to operate the operation unit 77.

[0073] The input / output control circuit board 75 is housed in the circuit board receiving recess 55b of the outer cover 55 and is positioned directly below the operation panel 73. The input / output control circuit board 75 includes: a microprocessor; a storage device that stores various arithmetic programs, parameters, and other digital information executed by the microprocessor; and a real-time clock (RTC) with a timing function. The storage device stores various settings (parameters) associated with multiple preset processes. The real-time clock has both a clock function (displaying the current time of the rice cooker 1) and a timing function. The real-time clock can be either the heating control circuit board 42 or the input / output control circuit board 75.

[0074] Display unit 76 is an output device that displays the current status of rice cooker 1 in a visually identifiable manner. Display unit 76 may be, for example, a display and a light-emitting diode (LED). The display may be a liquid crystal display (LCD) or an organic EL panel (Organic Electro-Luminescence, Organic Light-Emitting Diode).

[0075] The operation unit 77 is an input device and a so-called touch sensor. The operation unit 77 is positioned directly above the display unit 76, covering it. The touch sensor has multiple button elements arranged on a plane. Each button element includes: a transparent electrode portion, which utilizes, for example, a conductive polymer; a contact portion connected to the input / output control circuit board 75; and patterned wiring connecting the transparent electrode portion and the contact portion. The operation of the button element positioned directly above any display element displayed on the display unit 76 is performed by touching, contacting, or approaching it with a fingertip. The operation received by the button element is output to the input / output control circuit board 75 as a selection of a display element on the display unit 76 displayed directly below it.

[0076] The user of rice cooker 1 can use the control unit 77 to select and input cooking conditions such as rice type, cooking method, hardness, and cooking time. Rice cooker 1 performs cooking waiting, rice and water heating, rice keeping warm, and cooking timer waiting based on the process set by the operation of the control unit 77.

[0077] However, it is assumed that the user of the rice cooker 1 operates the control panel 73 while standing facing the front of the rice cooker 1. Therefore, the rice cooker 1 according to this embodiment includes: a lid opening operation button 71, which is disposed on the front half of the upper surface near the user facing the front of the rice cooker 1; and a steam vent 65, which is disposed on the rear half of the upper surface away from the user facing the front of the rice cooker 1. Therefore, the rice cooker 1 according to this embodiment can easily ensure a large space for disposing the display 76 between the lid opening operation button 71 and the steam vent 65, and can set the size of the operation part 77 disposed directly above the display 76 to be as large as possible. Therefore, the rice cooker 1 can obtain higher visual visibility of the display 76, higher operability of the operation part 77, and higher safety for steam discharged from the steam vent 65.

[0078] Furthermore, the rice cooker 1 according to this embodiment does not have physical operation buttons, such as cooking and cut buttons, found in conventional rice cookers, and can be operated using only the operation unit 77. Therefore, the rice cooker 1 according to this embodiment can save time searching for operation buttons, thereby achieving intuitive operation. In addition, the rice cooker 1 without physical operation buttons improves space utilization efficiency by centrally arranging the display unit 76 and the operation unit 77, and it is easier to design a very compact appearance compared to conventional rice cookers with input and output devices scattered. Moreover, the upper surface of the rice cooker 1 without physical operation buttons can be made into a flat surface with almost no unevenness or a gently curved surface. Regarding the shape of the upper surface of the rice cooker 1, it is easy to wipe and clean.

[0079] Figure 3 This is a cross-sectional view of the inner frame and heating coil of the rice cooker involved in this embodiment.

[0080] Figure 4 This is a bottom view of the inner frame and heating coil of the rice cooker involved in this embodiment.

[0081] like Figure 3 and Figure 4 As shown, the heating coil 31 of the rice cooker 1 involved in this embodiment includes multiple coils 31u and 31d.

[0082] The first coil 31u is disposed on the outer side of the inner frame 37, and the second coil 31d is disposed on the bottom outer surface of the inner frame 37. The first coil 31u is positioned opposite the lower part of the outer side of the pot 25 through the inner frame 37. The second coil 31d is positioned opposite the bottom outer surface of the pot 25 through the inner frame 37.

[0083] The movement of heat when the heating coil 31 is energized will be explained.

[0084] When the first coil 31u is energized, the lower outer surface of the pot 25 heats up first. This heat is conducted to the main body 25a of the pot 25 and moves towards the water contained in the food being cooked, which is in contact with the lower inner surface of the pot 25. The movement of heat within the food is primarily accompanied by the movement of water, i.e., convection. Where rice is present in the food, the movement of water is limited to the narrow gaps between the rice grains, and the movement of water and heat is sluggish. On the other hand, where no rice is present, the movement of water and heat, i.e., convection, becomes active. Therefore, immediately following the water in contact with the lower inner surface, the water in the upper part of the food heats up. The rice grains settle downwards due to their own weight, so the upper part of the food contains almost no rice grains and is essentially only water. Then, in the central part of the food, the water and heat from the upper part, which has become hot, move towards the still-cooler middle part of the food, and further towards the lower part of the food. This phenomenon is known as thermal convection, referred to as “external convection” based on the first coil 31u.

[0085] Furthermore, when the second coil 31d is energized, the outer surface of the bottom of the pot 25 heats up first. This heat is conducted to the main component 25a of the pot 25 and moves towards the inner surface of the bottom of the pot 25, where the water contained in the lower layer of the food being cooked is in contact with the so-called bottom of the pot. The rice grains settle downwards due to their own weight, thus the bottom of the pot is covered by the rice and water contained in the lower layer of the food being cooked. Therefore, the heat at the bottom of the pot increases the temperature and pressure of the water covering the bottom. Then, the water at the bottom of the pot, after its temperature and pressure increase, moves upwards through the gaps between the rice grains contained in the food being cooked. That is, the water heated in the lower layer of the food being cooked, i.e., hot water, moves along with the heat to the middle layer of the food being cooked, and then to the upper layer of the food being cooked. This phenomenon is called "blowing," or "internal convection" based on the second coil 31d.

[0086] Furthermore, if the first coil 31u and the second coil 31d are alternately energized, external convection and internal convection are alternately generated for the food being cooked in the pot 25. That is, if the first coil 31u and the second coil 31d are alternately energized, the alternating external and internal convection promotes the stirring of the water contained in the food being cooked in the pot 25, thereby reducing uneven heating of the food being cooked.

[0087] The heating control circuit board 42 of the rice cooker 1 according to this embodiment enables the heating coil 31 to operate by various combinations of the energizing time of the first coil 31u, the energizing time of the second coil 31d, the output of the first coil 31u, and the output of the second coil 31d. These various energizing types are stored in a storage unit.

[0088] One of the preferred energizing types is as follows: after energizing the first coil 31u with the first output W1 and the first energizing time T1, the second coil 31d is energized with the second output W2 and the second energizing time T2. Preferably, each energizing time T1 and T2 is several seconds or more. This generates alternating external and internal convection for the food being cooked in the pot 25 for a predetermined time or longer. The alternation of external and internal convection promotes agitation of the water in the food being cooked in the pot 25, thus reducing uneven heating.

[0089] Preferably, the first energizing time T1 and the second energizing time T2 are different. That is, it is preferable that the time for generating external convection and the time for generating internal convection with a certain energizing type are different.

[0090] The energizing type can include the following: changing either the energizing time or the output of the heating coil 31 while keeping the other constant. Alternatively, the energizing time of each coil 31u and 31d can be constant, while the output of each coil 31u and 31d is different. Furthermore, the output of each coil 31u and 31d can be constant, while the energizing time of each coil 31u and 31d is different.

[0091] Various energizing types can include the following: a no-energizing time that cuts off the energizing of all heating coils 31. That is, as an energizing type, after energizing one of the two coils 31u and 31d for a predetermined energizing time and output, if a first no-energizing time has elapsed, then energizing the other of the two coils 31u and 31d for a predetermined energizing time and output, and waiting for a second no-energizing time to elapse. The first no-energizing time and the second no-energizing time can be the same or different.

[0092] Additionally, the energizing type can include the following: intermittently energizing only one of the two coils 31u and 31d while not energizing the other coil (no energizing). With this energizing type, one of the two coils 31u and 31d is energized for a specified energizing time and with a specified energizing output, while neither coil is energized during the specified energizing time. This energizing type is suitable for heat preservation processes.

[0093] Repeat the above-mentioned energizing type at a specified time or a specified number of times.

[0094] If the power-on type is switched, the first power-on type, which involves energizing the first coil 31u with the first output W1 and the first power-on time T1 followed by energizing the second coil 31d with the second output W2 and the second power-on time T2, is switched to the second power-on type, which involves energizing the first coil 31u with the third output W3 and the third power-on time T3 followed by energizing the second coil 31d with the fourth output W4 and the fourth power-on time T4. Each power-on type is executed repeatedly for a specified time or a specified number of times before and after the switch.

[0095] The content of each power-on type and the combination of multiple power-on types are appropriately set according to the various steps included in the process.

[0096] Regarding the power supply type, the output adjustment of the first coil 31u and the output adjustment of the second coil 31d are based on PWM control (Pulse Width Modulation).

[0097] Next, the cover 26 will be described in detail.

[0098] Figure 5 This is an exploded perspective view of the rice cooker according to this embodiment, and it shows the state after the control panel of the lid has been removed.

[0099] Figure 6 This is a top view of the outer lid of the rice cooker according to this embodiment.

[0100] Figure 7 This is an enlarged cross-sectional view of the outer cover of the rice cooker according to this embodiment, and a cross-sectional view of the surface through which the circuit board receiving recess is transversely cut in the width direction of the rice cooker.

[0101] like Figure 5 and Figure 6 As shown, the lid 26 of the rice cooker 1 according to this embodiment includes: an outer cover 55 having a recessed portion 55a that opens away from the main body 23 and covers the outer cover cover 56; and an operation panel 73 as the upper surface panel, which covers the recessed portion 55a. A small gap is formed between the operation panel 73 and the outer cover 55, which is an adjacent component of the operation panel 73. This gap is not wide enough for liquids, such as water abundant in a kitchen envisioned as the installation location of the rice cooker 1, to flow in violently. However, there is room for liquids to seep into the interior of the lid 26 through the gap between the operation panel 73 and the outer cover 55 due to capillary action.

[0102] The lid 26 of the rice cooker 1 according to this embodiment also includes a clamping switch CS as an electrical component. This clamping switch CS serves as a monitoring unit for the opening and closing of the lid 26 by power monitoring via the operation of the lid opening button 71. The clamping switch CS is a component of the lid locking mechanism 72 and is a sensor that monitors the downward pressing operation of the lid opening button 71 to open the lid 26. The clamping switch CS is provided on the outer cover 55 and is covered by the operation panel 73. The construction of the clamping switch CS can be based on, for example, the technology disclosed in Japanese Patent Application Publication No. 2023-151879.

[0103] Therefore, in Figure 5 and Figure 6 On the basis of, and such Figure 7 As shown, the outer cover 55 of the cover 26 according to this embodiment has: a drain groove 202, which is provided along at least a portion of the edge of the recess 55a, and is inclined in such a way that when liquid seeps into the recess 55a through the gap between the operation panel 73 and the outer cover 55, the liquid is guided toward the drain hole 201, which allows the liquid to flow out into the space defined by the outer cover 55 and the outer cover cover 56; and a storage section 204, which temporarily stores the liquid flowing from the drain groove 202 to the drain hole 201. The drain groove 202 captures the liquid that has infiltrated the interior of the cover 26 through the gap between the operation panel 73 and the outer cover 55 before it flows toward the center of the recess 55a, and allows the liquid to flow out into the space defined by the outer cover 55 and the outer cover cover 56 through the drain hole 201.

[0104] However, in recent years, from the perspective of setting volume, the demand for miniaturization of the rice cooker 1 has increased. On the other hand, from the perspective of visual confirmation of the display section 76, the demand for larger displayed text has increased, and from the perspective of operability of the operation section 77, the demand for larger keycaps 73b has increased. That is, the current situation is that on the one hand, there is a demand for miniaturization of the cover 26, and on the other hand, there is a demand for larger input / output control circuit board 75. Therefore, the proportion occupied by the circuit board receiving recess 55b in the recess 55a of the outer cover 55 has increased, and the edge of the recess 55a and the edge of the circuit board receiving recess 55b are very close.

[0105] Furthermore, if liquid seeps into the recess 55a through the gap between the operation panel 73 and the outer cover 55, the liquid will flow into the circuit board receiving recess 55b near the edge of the recess 55a. The circuit board receiving recess 55b houses the input / output control circuit board 75, which is mounted on the operation unit 77 as an input device and the display unit 76 as a display device. Therefore, if liquid flows into the circuit board receiving recess 55b, it may cause a malfunction of the input / output control circuit board 75 housed in the circuit board receiving recess 55b.

[0106] Therefore, the drain channel 202 is laid at least along the portion close to the circuit board receiving recess 55b and the recessed portion 55a. For convenience, the portion of the drain channel 202 laid along the portion close to the circuit board receiving recess 55b and the recessed portion 55a is called the "narrow portion drain channel 202a", and for convenience, the drain channel 202 other than the narrow portion drain channel 202a is called the "non-narrow portion drain channel 202b". The narrow portion drain channel 202a extends along the left and right sides of the circuit board receiving recess 55b in the front-back direction of the rice cooker 1.

[0107] Preferably, it has multiple drain holes 201. Multiple drain holes 201 can facilitate the discharge of liquid captured by the drain tank 202 over a wide area.

[0108] The plurality of drainage holes 201 includes: a plurality of side drainage holes 201a disposed within the narrow portion of the drainage groove 202a in the drainage groove 202; and a plurality of front drainage holes 201b disposed at the leading edge of the recess 55a. In other words, the plurality of drainage holes 201 includes at least a plurality of side drainage holes 201a disposed at the portion close to the circuit board receiving recess 55b and the recess 55a.

[0109] Multiple side drain holes 201a reliably prevent liquid captured by the narrow drain 202a and liquid captured by the non-narrow drain 202b and flowing into the narrow drain 202a from rapidly flowing out to the upper surface of the outer cover 56, thus preventing liquid from overflowing into the circuit board receiving recess 55b.

[0110] The front drain hole 201b is located near the cover locking mechanism 72. Liquid discharged from the front drain hole 201b enters the cover body 26 through the gap between the opening 73c of the operation panel 73 exposing the cover opening operation button 71 and the cover opening operation button 71, and merges with the liquid collected by the outer cover 56 near the cover locking mechanism 72. The structure for discharging the merged liquid to the outside can be any technology disclosed in, for example, Japanese Patent Application Publication No. 2023-151879.

[0111] The left and right edges of the circuit board receiving recess 55b are close to the left and right edges of the recess 55a. On the other hand, the leading edge of the circuit board receiving recess 55b is separated from the leading edge of the recess 55a, and the trailing edge of the circuit board receiving recess 55b is separated from the trailing edge of the recess 55a. A narrow portion drainage groove 202a is disposed between the left and right edges of the circuit board receiving recess 55b and the left and right edges of the recess 55a. A non-narrow portion drainage groove 202b is laid along the leading edge and trailing edge of the recess 55a.

[0112] The drainage channel 202 can be laid along the entire circumference of the edge of the recess 55a. Multiple drainage holes 201 can be discretely arranged along the entire length of the drainage channel 202, including the narrow drainage channel 202a.

[0113] With the main body 23 closed by the lid 26, the drain trough 202 slopes downwards from the rear side to the front side of the rice cooker 1. In other words, the drain trough 202 slopes downwards from the rear to the front of the outer cover 55. Liquid flowing into the narrow drain trough 202a flows rapidly out through the side drain hole 201a onto the upper surface of the outer cover 56, which serves as a drain tray. Liquid flowing into the drain trough 202 from areas other than the narrow drain trough 202a is captured by the drain trough 202 and diffuses along the drain trough 202 depending on the amount of liquid. The drain trough 202 has multiple downstream ends. Liquid captured by the portion of the drain trough 202 further rear than the narrow drain trough 202a flows out onto the upper surface of the outer cover 56 upon reaching the side drain hole 201a.

[0114] Multiple storage sections 204 are disposed at the front of the outer cover 55. The storage sections 204 are respectively located at multiple downstream ends of the drainage trough 202. For example... Figure 5 and Figure 6 As shown, the first storage section 204a of the storage section 204 is located to the right of the cover opening operation button 71. Furthermore, the first storage section 204a is positioned between the drain groove 202 and the clamping switch CS, and is located near the clamping switch CS. On the other hand, the second storage section 204b is located to the left of the cover opening operation button 71.

[0115] The front drain hole 201b is located downstream of the liquid flow path in the storage section 204. Liquid captured by the portion of the drain trough 202 further forward than the narrow drain trough 202a flows into the storage section 204 and reaches the front drain hole 201b before flowing out onto the upper surface of the outer cover 56. The structure for discharging the liquid flowing out onto the upper surface of the outer cover 56 to the outside can be achieved by using, for example, the known technology disclosed in Japanese Patent Application Publication No. 2023-141040.

[0116] Not only is the first storage section 204a positioned near the clamping switch CS, but a second storage section 204b is also positioned on the opposite side, with the operation button 71 opened through the cover. This improves overall drainage efficiency, thus helping to prevent water from seeping into the clamping switch CS. In particular, to reduce the number of components and cost, the protective retaining member for the clamping switch CS has been removed, making water prevention crucial. Furthermore, for example, Japanese Patent Application Publication No. 2023-151879 discloses an example of a clamping switch with a retaining member.

[0117] Figure 8This is an enlarged cross-sectional view of the outer lid of the rice cooker according to this embodiment, and it is a cross-sectional view along the drain groove.

[0118] exist Figure 5 and Figure 6 On the basis of, and such Figure 8 As shown, the depth of the narrow portion drainage groove 202a of the cover 26 according to this embodiment is deeper than the depth of the non-narrow portion drainage groove 202b. The narrow portion drainage groove 202a, such as the deep groove, can prevent liquid captured by the narrow portion drainage groove 202a and liquid captured by the non-narrow portion drainage groove 202b and flowing into the narrow portion drainage groove 202a from overflowing into the circuit board receiving recess 55b.

[0119] Furthermore, compared to the left and right edges of the circuit board receiving recess 55b and the left and right edges of the recess 55a, the front and rear edges of the circuit board receiving recess 55b and the front and rear edges of the recess 55a are isolated. Therefore, it is assumed that even if liquid overflows from the non-narrow portion drain groove 202b, the liquid will not immediately flow into the circuit board receiving recess 55b. Additionally, it is envisioned that a large amount of liquid overflowing from the non-narrow portion drain groove 202b to the extent that it reaches the circuit board receiving recess 55b will flow into the interior of the cover 26 through the gap between the operation panel 73 and the outer cover 55.

[0120] The outer cover 55 has ribs 203 positioned above the side drainage holes 201a and supported by the drainage channel 202. Since the left and right edges of the circuit board receiving recess 55b and the left and right edges of the recessed portion 55a are close together, when the outer cover 55 is molded from synthetic resin, there is a molding risk that the side drainage holes 201a on the outer cover 55 may cause the outer cover 55, which corresponds to the embankment defining the recessed portion 55a, to tilt inwards towards the recessed portion 55a. Therefore, by supporting the ribs 203 above the side drainage holes 201a, the outer cover 55 can be molded in a desired manner.

[0121] The rice cooker 1 of this embodiment, configured as described above, includes a drain groove 202. This drain groove 202 is provided along at least a portion of the edge of the recess 55a. When liquid seeps into the recess 55a through the gap between the control panel 73 and the outer cover 55, it guides the liquid towards a drain hole 201, which allows the liquid to flow into the space defined by the outer cover 55 and the outer cover 56. Therefore, the rice cooker 1 can capture the liquid that has infiltrated the interior of the lid 26 through the gap between the control panel 73 and the outer cover 55 before it flows towards the center of the recess 55a, and allow the liquid to flow out through the drain hole 201 into the space defined by the outer cover 55 and the outer cover 56.

[0122] Furthermore, the rice cooker 1 according to this embodiment has a plurality of drain holes 201 provided in the drain tank 202. Therefore, the rice cooker 1 can facilitate the discharge of liquid captured by the drain tank 202 over a wide area of ​​the drain tank 202.

[0123] Furthermore, the rice cooker 1 according to this embodiment includes a rib 203, which is disposed above the drain hole 201 and supported on the drain trough 202. Therefore, the rice cooker 1 can have an outer cover 55 such that even though the outer cover 55, which is a molded product of synthetic resin, is provided with a side drain hole 201a, it is possible to prevent the outer surface of the outer cover 55, which corresponds to the embankment that divides the recessed portion 55a, from tilting towards the inside of the recessed portion 55a, thereby having a desired appearance.

[0124] Furthermore, the rice cooker 1 according to this embodiment has a drainage channel 202, i.e., a narrow drainage channel 202a, laid at least along the portion close to the circuit board receiving recess 55b and recess 55a. Therefore, the rice cooker 1 can simultaneously meet the requirements for miniaturization of the rice cooker 1, the requirement for improved visual visibility of the display 76, and the requirement for improved operability of the operation 77, and can reliably prevent the input / output control circuit board 75, which is envisioned to be large-scale, from malfunctioning due to liquids such as water.

[0125] Furthermore, the rice cooker 1 according to this embodiment has at least a drain hole 201, i.e., a side drain hole 201a, located near the circuit board receiving recess 55b and recess 55a. Therefore, the rice cooker 1 can allow the liquid captured by the narrow drain groove 202a to flow out extremely quickly into the space carved out by the outer cover 55 and the outer cover cover 56, thereby reliably preventing the input / output control circuit board 75 from malfunctioning.

[0126] Therefore, the rice cooker 1 of the present invention can smoothly drain liquid that has entered the interior of the lid 26 from the gap between the operation panel 73, which is equivalent to the top plate of the lid 26, and the outer cover 55, which is an adjacent component thereto.

[0127] The inner lid unit 59 that closes the pot 25 will be described. Figure 9 This is a perspective view of the inner lid unit of the rice cooker according to this embodiment, viewed from the top, i.e., the lid side.

[0128] Figure 10 This is a perspective view of the inner lid unit of the rice cooker according to this embodiment, viewed from the bottom, i.e., the main body side.

[0129] like Figure 9 and Figure 10As shown, the inner lid 61 of the rice cooker 1 according to this embodiment is detachably mounted on the lid body 26. When the main body 23 is closed by the lid body 26, the inner lid 61 closes the pot 25. The inner lid 61 has an upper and lower surface that are flat or have a very gentle curved shape and are without any bumps or depressions in the part that closes the pot and defines the space inside the pot. When the main body 23 is closed by the lid body 26, the lower surface of the inner lid 61 and the inner surface of the pot 25 cooperate to define the space inside the pot. The lower and upper surfaces of the inner lid 61 need to be cleaned during cooking, and the flat lower and upper surfaces of the inner lid 61 are extremely easy to clean.

[0130] Additionally, the inner cover 61 has multiple holes that connect the interior space of the pot to the space outside the pot 25. These holes include: a pressure regulating hole 81 that allows steam to escape from the interior space of the pot or allows atmosphere to flow into the interior space of the pot; a high-pressure exhaust hole 82 that allows steam to escape from the interior space of the pot if the internal pressure of the pot 25 exceeds a specified pressure; and a pressure reducing hole 69 connected to a pressure reducing pump 68 that releases gas from the interior space of the pot to reduce the internal pressure of the pot 25.

[0131] The pressure regulating port 81 and the high-pressure exhaust port 82 are equivalent to the inlet of the steam exhaust path, and the steam port 65 is equivalent to the outlet of the steam exhaust path.

[0132] The inner cover 61 has no unevenness on its upper and lower surfaces, including around the multiple holes, making it extremely easy to clean.

[0133] Next, the steam exhaust path for discharging steam from inside the pot 25 to outside the rice cooker 1 will be described in detail. The steam exhaust path is the path for discharging steam generated inside the pot 25 to outside the rice cooker 1, and it also functions as an air intake path for restoring the internal pressure of the pot 25, which has been reduced by the pressure-reducing action of the pressure-reducing pump 68, to atmospheric pressure, allowing the atmosphere of the rice cooker 1 to flow into the pot 25. That is, the rice cooker 1 can pressurize or depressurize the space inside the pot by cutting off the flow of gas through the steam exhaust path, and by allowing the flow of gas through the steam exhaust path, the space inside the pot can be substantially formed at atmospheric pressure.

[0134] In addition, the decompression path for depressurizing the space inside the pot by venting gas from inside the pot 25 to outside the rice cooker 1 is explained.

[0135] Figure 11 This is a partial bottom view of the lid of the rice cooker according to this embodiment.

[0136] like Figure 11As shown, the lid 26 of the rice cooker 1 according to this embodiment includes: a steam exhaust path 66, which cooperates with the inner lid 61 to delineate a steam exhaust path; a pressure regulating gasket 95, which surrounds the inlet side of the steam exhaust path 66; a pressure regulating valve 67; a safety valve 97, which allows or cuts off the flow of gas in the steam exhaust path 66; a pressure reducing gasket 98, which airtightly connects the path communicating with the pressure reducing pump 68 and the pressure reducing hole 69 of the inner lid 61; and an inner lid mounting sensor 99, which monitors whether the inner lid unit 59 is mounted on the lid 26.

[0137] If the inner cover unit 59 is assembled onto the cover body 26, the pressure regulating gasket 95 presses against and abuts against the upper surface of the inner cover 61, thus airtightly connecting the pressure regulating hole 81, the high-pressure exhaust hole 82, and the steam exhaust path 66. The pressure regulating gasket 95 seals the gap between the steam exhaust path 66 and the upper surface of the inner cover 61 such that the pressure regulating valve 67 and the safety valve 97 are enclosed within the steam exhaust path. The pressure regulating gasket 95 guides the steam flowing from the pressure regulating hole 81 and the high-pressure exhaust hole 82 in the boiler 25 to the steam exhaust path 66, and also guides the atmosphere and external gas flowing in from the steam port 65 to the pressure regulating hole 81 and the high-pressure exhaust hole 82. That is, the space on the inner periphery of the pressure regulating gasket 95 is part of the steam exhaust path 66 and also part of the steam exhaust path. In addition, a portion of the upper surface of the inner cover 61 serves as part of the steam exhaust path 66 and also as part of the steam exhaust path.

[0138] If the inner cover unit 59 is assembled onto the cover body 26, the pressure-reducing gasket 98 is pressed against and abuts against the upper surface of the inner cover 61, thereby airtightly connecting the path communicating with the pressure-reducing pump 68 and the pressure-reducing hole 69. The pressure-reducing gasket 98 guides the gas flowing out of the pot 25 from the pressure-reducing hole 69, which corresponds to the inlet of the pressure-reducing path, to the pressure-reducing pump 68.

[0139] Figure 12 This is a perspective view of the interior of the lid of the rice cooker according to this embodiment, and it shows the operation panel of the lid and the lid after the outer cover is removed.

[0140] like Figure 12As shown, in this embodiment, the suction side of the pressure reducing pump 68 of the rice cooker 1 is connected to the pressure reducing hole 69 of the inner cover 61 via the pressure reducing gasket 98. The pressure reducing pump 68 discharges gas inside the pot 25 through the pressure reducing hole 69 to the outside of the rice cooker 1, thereby reducing the internal pressure of the pot 25. When the internal pressure of the pot 25 is reduced, the pot 25 is housed in the pot housing 21, the cover 26 is closed, and the pressure regulating valve 67 is closed. When the internal pressure of the pot 25 is restored from the reduced pressure state to atmospheric pressure, the pressure reducing pump 68 is stopped and the pressure regulating valve 67 is opened. Thus, the inside of the pot 25 is connected to the outside of the rice cooker 1, allowing external gas to flow into the pot 25. The passage connecting the pressure reducing pump 68 and the pressure reducing hole 69 may include a pressure reducing valve 70 that allows or cuts off the flow of gas. The pressure reducing valve 70 may be a check valve that allows the pressure reducing pump 68 to draw gas from the pot's internal space and prevents gas from flowing back from the pressure reducing pump 68 into the pot's internal space, or it may be a solenoid valve that can be electrically controlled to open and close.

[0141] In other words, the pressure reducing pump 68 and the pressure regulating valve 67 function as pressure reducing parts that can reduce the internal pressure of the pot 25 to a pressure reducing state below atmospheric pressure, and the pressure regulating valve 67 also functions as a pressure increasing part that can increase the internal pressure of the pot 25 to a pressure increasing state above atmospheric pressure.

[0142] Figure 13 This is an enlarged cross-sectional view of the steam exhaust path and pressure regulating valve of the rice cooker involved in this embodiment.

[0143] like Figure 12 and Figure 13 As shown, in this embodiment, the steam discharge path 66 of the rice cooker 1 discharges the steam that flows in from the pressure regulating hole 81 from the steam outlet 65.

[0144] The steam discharge path 66 includes: a first discharge path 101; and a second discharge path 102, which is connected to the downstream side of the first discharge path 101 in the steam flow direction, and causes the steam flow direction of the first discharge path 101 to be reversed.

[0145] Here, "reversing the flow direction of steam" means that when steam flows from the upstream flow path to the downstream flow path, the flow direction of steam is actually bent and reversed within the range of 90 degrees to 180 degrees.

[0146] The first discharge passage 101 and the second discharge passage 102 have overlapping portions in the direction away from the inner cover 61. That is, in the top view of the rice cooker 1, the first discharge passage 101 and the second discharge passage 102 have overlapping portions.

[0147] The first discharge path 101 and the second discharge path 102 each include multiple small paths 105 that cause the steam flow direction to reverse.

[0148] The first discharge path 101 is connected to the pressure regulating hole 81. The first discharge path 101 includes: a first small path 105a, which is connected to the pressure regulating hole 81; a second small path 105b, which is connected to the first small path 105a; and a third small path 105c, which is connected to the second small path 105b.

[0149] The second discharge path 102 is connected to the steam outlet 65. The second discharge path 102 includes: a fourth minor path 105d, which is connected to the third minor path 105c; and a fifth minor path 105e, which is connected to the fourth minor path 105d and reaches the steam outlet 65.

[0150] Additionally, the steam discharge path 66 includes: a first portion 107, which is integrally formed with the outer cover 56 of the cover body 26 and supports the valve core 67a; a second portion 108, which has a steam port 65; and an elastic partition wall 109, which is sandwiched between the first portion 107 and the second portion 108.

[0151] The first part 107 is a portion of the wall that defines the first discharge path 101. The first part 107, the inner cover 61, and the elastic partition wall 109 cooperate to define the first discharge path 101. The first part 107 and the outer cover 56 are integrally molded. That is, the first part 107 and the outer cover 56 are both molded products of synthetic resin, such as polypropylene (PP).

[0152] The first minor path 105a and the second minor path 105b are adjacent to and connected along the upper surface of the inner cover 61. The first minor path 105a and the second minor path 105b surround the valve core 67a of the pressure regulating valve 67 and are separated by an arcuate wall 107a connected to a portion of the valve box that supports the valve core 97a of the safety valve 97. The arcuate wall 107a is integrally formed with the first portion 107 and does not close the first minor path 105a until it reaches the pressure regulating pad 95.

[0153] The second sub-path 105b and the third sub-path 105c are separated by a weir-shaped upright wall 107b extending away from the inner cover 61. The upright wall 107b is integrally formed with the first portion 107 and does not close the second sub-path 105b by reaching the elastic partition wall 109. In other words, the upright wall 107b is separated from the elastic partition wall 109. The upright wall 107b is a molded product of a synthetic resin, such as polypropylene (PP), and is a non-elastic partition wall with extremely high rigidity compared to the elastic partition wall 109.

[0154] The second part 108 is a portion of the wall that defines the second discharge path 102. The second part 108 and the elastic partition wall 109 cooperate to define the second discharge path 102. The second part 108 is a molded product made of synthetic resin, such as polypropylene (PP).

[0155] The fourth sub-path 105d and the fifth sub-path 105e are separated by a drooping wall 108a that hangs down from the top of the second portion 108 and abuts against the elastic partition wall 109. The drooping wall 108a is integrally formed with the second portion 108 and does not reach the inner side of the second portion 108 to close the fourth sub-path 105d. In other words, the drooping wall 108a is away from the inner side of the second portion 108. The drooping wall 108a is a molded article of a synthetic resin, such as polypropylene (PP), and is a non-elastic partition wall with extremely high rigidity compared to the elastic partition wall 109. In other words, the drooping wall 108a is a non-elastic partition wall that abuts against the elastic partition wall 109 and separates the fourth sub-path 105d and the fifth sub-path 105e.

[0156] The third sub-path 105c and the fourth sub-path 105d are separated by an elastic partition wall 109 and connected by a cylindrical deflecting conduit 109a integrally formed with the elastic partition wall 109. Specifically, the deflecting conduit 109a connects the first discharge path 101 and the second discharge path 102. The deflecting conduit 109a extends away from the inner cover 61, and its opening faces the drooping wall 108a that separates the fourth sub-path 105d and the fifth sub-path 105e.

[0157] The elastic partition wall 109 is, for example, a monolithic molded product of silicone rubber, possessing elasticity, and separates the first discharge path 101 and the second discharge path 102. In other words, the elastic partition wall 109 is equivalent to a partition wall separating the first discharge path 101 and the second discharge path 102. Additionally, the elastic partition wall 109 is a partition wall that separates the second minor path 105b and the third minor path 105c of the first discharge path 101 from the fourth minor path 105d and the fifth minor path 105e of the second discharge path 102.

[0158] However, when the first discharge path 101 and the second discharge path 102 are separated by a non-elastic partition wall, and the component sandwiched between the first part 107 and the second part 108 is a molded product of synthetic resin, such as polypropylene (PP), a seal is required between this component and the first part 107, and between this component and the second part 108, to prevent steam leakage. On the other hand, the elastic partition wall 109 sandwiched between the first part 107 and the second part 108 also serves as a seal. That is, the steam discharge path 66 with the elastic partition wall 109 reduces the number of components compared to the case where the first discharge path 101 and the second discharge path 102 are separated by a non-elastic partition wall.

[0159] The first small path 105a is the space defined between the valve core 67a of the pressure regulating valve 67 and the pressure regulating hole 81 of the inner cover 61 opposite the valve core 67a. The first small path 105a has a smaller volume compared to the other small paths 105, and the steam flowing from the pressure regulating valve 67 into the first small path 105a quickly flows into the second small path 105b. At this time, the steam flowing into the first small path 105a first flows towards the valve core 67a of the pressure regulating valve 67, and flows out into the second small path 105b approximately at a right angle towards the gap between the arcuate wall 107a and the pressure regulating gasket 95, which connects the first small path 105a and the second small path 105b.

[0160] The second small path 105b, the third small path 105c, the fourth small path 105d, and the fifth small path 105e have an overall chimney-like shape. That is, the steam flowing out from the first small path 105a flows into this chimney-shaped part. The second small path 105b and the fifth small path 105e overlap near the center of the cover 26, ensuring a large width within the cover 26. The third small path 105c and the fourth small path 105d are positioned on the back side of the cover 26 when viewed from the second small path 105b and the fifth small path 105e, and ensure a smaller width within the cover 26 compared to the second small path 105b and the fifth small path 105e. The third small path 105c and the fourth small path 105d can be positioned on the back side of the second small path 105b and the fifth small path 105e, or they can be positioned near the right side, near the left side, or near the center of the second small path 105b and the fifth small path 105e. By positioning the third sub-path 105c and the fourth sub-path 105d near the right or left side of the second sub-path 105b and the fifth sub-path 105e, space can be easily ensured within the cover 26 for various devices, such as wireless communication modules, or for the pressure reducing pump 68.

[0161] Furthermore, the second small path 105b is a space surrounded by the first portion 107, the elastic partition wall 109, and the vertical wall 107b. The second small path 105b has a larger volume compared to the other small paths 105. Therefore, the steam flowing from the first small path 105a to the second small path 105b is released from the narrow first small path 105a to the wide second small path 105b, and a portion of it condenses into liquid water due to the cooling effect caused by adiabatic expansion. The steam flowing from the first small path 105a to the second small path 105b flows along the upper surface of the inner cover 61 to the vertical wall 107b. Moreover, the steam reaching the vertical wall 107b changes its direction of flow approximately at a right angle from the direction of leaving the inner cover 61 and rises within the second small path 105b to reach the lower surface of the elastic partition wall 109. The steam reaching the lower surface of the elastic partition wall 109 will flow out towards the gap between the elastic partition wall 109 and the vertical wall 107b, which connects the second small path 105b and the third small path 105c, at approximately a right angle.

[0162] The second minor path 105b is integrally formed with the outer cover 56, which is integrally formed with the first part 107. The cross-sectional area of ​​the air passage of the second minor path 105b is larger than the opening area of ​​the pressure regulating hole 81, larger than the opening area of ​​the high-pressure exhaust hole 82, and larger than the opening area of ​​the steam port 65. In other words, the steam exhaust path 66 expands the air passage between the pressure regulating hole 81 and the high-pressure exhaust hole 82, which serve as the inlet of the steam exhaust path, and the steam port 65, which serves as the outlet of the steam exhaust path.

[0163] Furthermore, in the bottom view of the cover 26, the second small path 105b has a fan-shaped or trapezoidal planar shape that expands towards the outer side of the cover 26 from its center, and delineates a hollow air passage extending along the vertical direction (surface-back direction) of the cover 26. The second small path 105b is open on the bottom surface of the cover 26. This shape of the second small path 105b reduces the occupancy of the steam exhaust path 66 at the center of the cover 26, which houses various sensors including the inner cover mounting sensor 99 and the solenoid 67b driving the pressure regulating valve 67, while increasing the occupancy of the steam exhaust path 66 at the outer periphery of the cover 26, which houses fewer components and devices. This increases the proportion of the volume of the second small path 105b in the volume of the cover 26, ensuring sufficient volume of the second small path 105b as needed. The increased volume of the second small path 105b causes the "slippery liquid" flowing into the second small path 105b to be retained in the steam exhaust path 66, inhibiting the slippery liquid from flowing out of the steam port 65 to the outside of the rice cooker 1. In addition, the shape of the second small path 105b is suitable for the user to hold a cloth with their fingers for cleaning, and it also has a suitable size (volume) for cleaning.

[0164] The third small path 105c is a space surrounded by the first part 107, the elastic partition wall 109, and the vertical wall 107b. Steam flowing from the second small path 105b to the third small path 105c exits from the vertical wall 107b along the lower surface of the elastic partition wall 109. Furthermore, steam reaching the deflection pipe section 109a changes its flow direction approximately at a right angle in the direction of exiting the inner cover 61 and rises within the deflection pipe section 109a, where its flow direction is further changed approximately at a right angle before being blown out.

[0165] Furthermore, in the third sub-path 105c, in addition to the steam flow towards the fourth sub-path 105d via the deflection pipe section 109a, a steam flow is also generated that passes through the deflection pipe section 109a along the lower surface of the elastic partition wall 109 and reaches the inner wall surface of the first part 107. If this steam flow reaches the wall surface of the first part 107, its direction of flow away from the elastic partition wall 109 changes to approximately a right angle and it descends within the third sub-path 105c, generating a circulating flow that merges again with the steam flowing from the second sub-path 105b to the third sub-path 105c along the bottom surface of the third sub-path 105c and then along the wall surface of the vertical wall 107b. Compared to the steam flow towards the fourth sub-path 105d via the deflection pipe section 109a, this circulating flow remains in the third sub-path 105c for a longer period of time.

[0166] The fourth minor path 105d is a space surrounded by the second part 108, the elastic partition wall 109, and the drooping wall 108a, allowing the deflection pipe section 109a, which is integral with the elastic partition wall 109, to enter significantly. Steam flowing from the third minor path 105c to the fourth minor path 105d is blown out of the deflection pipe section 109a and toward the drooping wall 108a. The steam reaching the drooping wall 108a diffuses along the wall surface of the drooping wall 108a. The steam blown to the wall surface of the drooping wall 108a flows toward the gap between the drooping wall 108a and the inner wall surface of the second part 108, which connects the fourth minor path 105d and the fifth minor path 105e, and flows out toward the fifth minor path 105e at a roughly right angle in this gap.

[0167] The fifth sub-path 105e is a space surrounded by the second part 108, the elastic partition wall 109, and the drooping wall 108a, and communicates with the steam port 65. The steam port 65 is integrally formed with the second part 108. The steam port 65 is the outlet of the cylindrical body 108b entering the fifth sub-path 105e. Steam flowing from the fourth sub-path 105d into the fifth sub-path 105e temporarily flows towards the upper surface of the elastic partition wall 109 around the cylindrical body 108b, and then the direction of flow changes approximately to a right angle and flows into the inlet of the cylindrical body 108b and is blown out from the steam port 65.

[0168] Therefore, the steam discharge path 66 causes the steam flowing in from the pressure reducing hole 69 to flow towards the rear of the rice cooker 1 through the first discharge path 101, and then towards the front of the rice cooker 1 through the second discharge path 102, thereby reversing the steam flow direction. In addition, the first small path 105a, the second small path 105b, the third small path 105c, the fourth small path 105d, and the fifth small path 105e also continuously reverse the steam flow direction approximately vertically at their respective connection points.

[0169] Furthermore, the steam discharge path 66 has: a first discharge hole 111 that discharges viscous liquid from the third sub-path 105c to the second sub-path 105b; and a second discharge hole 112 that discharges viscous liquid from the second discharge path 102 to the first discharge path 101. The second discharge hole 112 is located behind the deflection pipe section 109a, where the influence of steam blown from the deflection pipe section 109a to the fourth sub-path 105d is less. The second discharge hole 112 discharges viscous liquid from the fourth sub-path 105d to the third sub-path 105c. There are multiple second discharge holes 112, for example, five, arranged in the width direction of the rice cooker 1.

[0170] Furthermore, the first small path 105a and the second small path 105b are continuously connected on the upper surface of the inner cover 61. Therefore, the viscous liquid discharged from the first discharge hole 111 can be returned to the pressure regulating hole 81.

[0171] Here, when the ratio of water to rice in the cooked food is appropriate, the amount of slurry generated by the cooking action of the rice cooker 1 is sufficient to capture it within the volume of the first discharge path 101. That is, the volumes of the third small path 105c and the second small path 105b are sufficient to separate the slurry generated when cooking a food containing water and rice in an appropriate ratio using the rice cooker 1, and the steam generated at that time. Therefore, the slurry retained in the third small path 105c returns to the second small path 105b through the first discharge hole 111, and the slurry retained in the second small path 105b returns to the first small path 105a through the upper surface of the inner cover 61. The slurry returning to the first small path 105a returns to the pot 25 through the pressure regulating hole 81 of the inner cover 61.

[0172] However, if the amount of water in the cooked food and the rice is too large, excessive mucus and steam may be generated. Therefore, the rice cooker 1 according to this embodiment also captures mucus in the second discharge path 102 and returns the mucus captured in the second discharge path 102 to the first discharge path 101 through the second discharge hole 112. The second discharge path 102, namely the fifth small path 105e and the fourth small path 105d, are continuously connected on the upper surface of the elastic partition wall 109. Therefore, the mucus captured in the fifth small path 105e returns to the fourth small path 105d through the gap between the hanging wall 108a and the inner side of the second part 108. The mucus returning to the fourth small path 105d returns to the third small path 105c of the first discharge path 101 through the second discharge hole 112. The mucus returning to the first discharge path 101 returns to the pressure regulating hole 81 in the same way as the mucus generated within the normal range. During the braising process, the pressure regulating valve 67 is opened, and the amount of steam discharged through the steam discharge path 66 is significantly reduced compared to the boiling heating process and the continuous boiling process. Therefore, the slurry returning to the pressure regulating hole 81 is easily returned to the pot 25 through the pressure regulating hole 81 during the braising process.

[0173] To improve the mucus discharge performance of the first discharge path 101 and the second discharge path 102, with the rice cooker 1 positioned on a horizontal plane as a reference—in other words, with the virtual plane in contact with the legs of the rice cooker 1 as a reference—the upper surface of the elastic partition wall 109 is inclined downwards toward the second discharge hole 112, and the bottom surface of the third small path 105c is inclined downwards toward the first discharge hole 111. The gradient of the upper surface of the elastic partition wall 109 and the gradient of the bottom surface of the third small path 105c only need to be within the range of 5 to 10 degrees. As long as the first discharge hole 111 is positioned at its lowest point relative to the upper surface of the elastic partition wall 109, and the second discharge hole 112 is positioned at its lowest point relative to the bottom surface of the third small path 105c, the shape of each surface can be planar, stepped, or mortar-shaped. The upper surface of the elastic partition wall 109 and the bottom surface of the third small path 105c with the above-described shapes reliably discharge the captured mucus.

[0174] Furthermore, sometimes steam flowing from the second small path 105b to the third small path 105c passes through the gap connecting the second small path 105b and the third small path 105c, i.e., the gap between the elastic partition wall 109 and the vertical wall 107b, and also through the first discharge hole 111. However, to ensure a longer steam flow path, it is preferable that the steam flowing from the second small path 105b to the third small path 105c passes through the gap between the elastic partition wall 109 and the vertical wall 107b. Therefore, it is preferable that the opening area of ​​the first discharge hole 111 is smaller than the opening area of ​​the gap connecting the second small path 105b and the third small path 105c, i.e., the gap between the elastic partition wall 109 and the vertical wall 107b. Similarly, it is preferable that the total opening area of ​​the plurality of second discharge holes 112 is smaller than the flow path cross-sectional area of ​​the deflection pipe section 109a.

[0175] However, among the cooking actions, namely the soaking and boiling process, the boiling heating process, the continuous boiling process, and the simmering process, the processes where sludge is more likely to flow into the steam exhaust path 66 are the boiling heating process and the continuous boiling process. Since the food being cooked is heated in the aforementioned boiling heating and continuous boiling processes, if the pressure regulating valve 67 is opened, allowing the space inside the pot to be exposed to the atmosphere, sludge may flow into the steam exhaust path 66. Furthermore, when the pressure regulating valve 67 is opened from the closed state, that is, when the pressure regulating port 81 is opened from a state where the internal pressure of the pot 25 is increased to above atmospheric pressure, the higher internal pressure of the pot 25 propagates rapidly and quickly through the steam exhaust path 66. This rapid increase in pressure in the steam exhaust path 66 may cause sludge or dew remaining in the steam exhaust path 66 to splash from the steam outlet 65.

[0176] Therefore, the rice cooker 1 according to this embodiment has an elastic partition wall 109, which is elastic and separates the first discharge passage 101 and the second discharge passage 102. When the pressure regulating hole 81 is opened, the internal pressure of the pot 25 propagates rapidly and drastically compared with the speed of steam flow in the order of the first small path 105a, the second small path 105b, the third small path 105c of the first discharge passage 101, and the fourth small path 105d and the fifth small path 105e of the second discharge passage 102. At this time, the pressure wave propagating towards the second small path 105b and the third small path 105c acts on the lower surface of the elastic partition wall 109, and the elastic partition wall 109 deforms convexly in the direction away from the inner cover 61, following the rapid and drastic pressure changes in the second small path 105b and the third small path 105c. The deformation of this elastic partition 109 temporarily increases the volume of the second and third sub-paths 105b and 105c, and moderates the pressure rise in the second and third sub-paths 105b and 105c. As a result, the pressure acting on the fourth and fifth sub-paths 105d and 105e is also moderated, reducing the possibility of viscous liquid and dew retained in the steam discharge path 66 splashing out of the steam outlet 65.

[0177] In addition, the rice cooker 1 according to this embodiment has a plurality of small paths 105 in the first discharge passage 101 and the second discharge passage 102. Therefore, the elastic partition wall 109 and the deformation of the elastic partition wall 109 accompanying the discharge of steam complement each other and can effectively suppress the movement of mucus and dew in the steam discharge passage 66.

[0178] Furthermore, it is envisioned that the elastic partition wall 109 deforms convexly from the first discharge path 101 side to the second discharge path 102 side due to the pressure accompanying the steam discharge. Therefore, preferably, the amount of deformation of the elastic partition wall 109 as the pressure in the steam discharge path 66 increases is set within a range that allows the elastic partition wall 109 to contact the cylindrical body 108b disposed in the second portion 108 of the fifth minor path 105e without obstructing the flow of steam in the second discharge path 102.

[0179] Furthermore, the attenuation effect of rapid and abrupt pressure changes in the steam discharge path 66 based on the elastic partition wall 109 also applies when the safety valve 97 is open. That is, the steam discharge path 66, which demarcates the steam exhaust path shared by the pressure regulating valve 67 and the safety valve 97, can attenuate rapid and abrupt pressure changes in the steam exhaust path even when either the pressure regulating valve 67 or the safety valve 97 is open.

[0180] The pressure regulating valve 67, also known as a pressure adjusting valve, is a valve portion 117 disposed on the cover 26. The pressure regulating valve 67 has a valve core 67a, which allows the flow of gas between the inside and outside of the pot 25 by opening the pressure regulating hole 81 of the inner cover 61, and cuts off the flow of gas between the inside and outside of the pot 25 by closing the pressure regulating hole 81 of the inner cover 61.

[0181] The pressure regulating valve 67 has a solenoid 67b that serves as a drive source for opening and closing the valve core 67a, and adjusts the internal pressure of the pot 25 after the inner cover 61 is closed. In addition to the valve core 67a and the valve core drive part 67c, the pressure regulating valve 67 also includes: a valve stem 67d that elastically supports the valve core 67a and transmits the driving force generated by the valve core drive part 67c to the valve core 67a; and a valve core support part 67e that supports the valve core 67a and the valve stem 67d so that they can reciprocate. The pressure regulating valve 67 opens or closes the valve core 67a by reciprocating the valve stem 67d, which is equivalent to a cam mechanism, through the valve core drive part 67c, which is equivalent to a cam mechanism driving member. That is, the pressure regulating valve 67 can open and close the pressure regulating port 81 by reciprocating the valve stem 67d and the valve core 67a together through the drive of the solenoid 67b. In addition, the pressure regulating valve 67 can open and close the pressure regulating port 81 by elastically moving the valve core 67a back and forth relative to the valve stem 67d.

[0182] The valve core 67a includes: a valve core base 67aa with a bottomed cylindrical shape; and a gasket 67ab, which is assembled to the valve core base 67aa.

[0183] When the inner cover unit 59 is assembled onto the cover body 26, the gasket 67ab faces the pressure regulating hole 81 of the inner cover 61. The gasket 67ab closes the pressure regulating hole 81 by contacting the upper surface of the inner cover 61, which corresponds to the valve seat of the pressure regulating valve 67, and opens the pressure regulating hole 81 by moving away from the upper surface of the inner cover 61. The gasket 67ab may have a planar shape that makes surface contact with the upper surface of the inner cover 61, but it may also have an annular protrusion that makes line contact with the upper surface of the inner cover 61 in a manner that surrounds the pressure regulating hole 81. The gasket 67ab, which makes line contact with the upper surface of the inner cover 61 in a manner that surrounds the pressure regulating hole 81, does not contact the upper surface of the inner cover 61 on one side, thus reliably closing the pressure regulating hole 81.

[0184] The valve stem 67d includes: a follower 67da having a pair of opposing cam follower surfaces 67db and 67dc; and an elastic body 67dd connecting the valve core base 67aa and the follower 67da. The valve stem 67d provides elastic support to the valve core 67a by means of the elastic body 67dd.

[0185] The follower 67da has a pair of mountain-shaped cam follower surfaces 67db and 67dc that protrude toward each other in a direction that approaches each other.

[0186] In addition, the follower 67da supports the valve core base 67aa in a manner that allows the valve core 67a to move forward and backward relative to the follower 67da in a direction close to the pressure regulating hole 81 and in a direction away from the pressure regulating hole 81, that is, in a manner that allows the valve core 67a to move back and forth independently.

[0187] Furthermore, the follower 67da holds the valve core 67a in a reciprocating motion state while the elastic body 67dd is clamped between the valve core base 67aa and the follower 67da. That is, the follower 67da and the valve core base 67aa are connected by a sliding mechanism that allows reciprocating motion and remains integrated in a manner that does not cause them to disintegrate. This sliding mechanism includes interlocking claws and claw supports, as well as a frame that defines the sliding direction.

[0188] The elastomer 67dd is clamped between the valve core base 67aa and the follower 67da in a state in which a compressive load is applied, such that the valve core 67a and the follower 67da are separated from each other.

[0189] The valve core support 67e supports the valve core 67a and valve stem 67d in a reciprocating manner, allowing them to move forward and backward in the direction approaching the pressure regulating hole 81 and in the direction away from the pressure regulating hole 81. The valve core support 67e is fixed to the outer cover 56.

[0190] The valve core drive unit 67c is disposed on the outer cover 56. The valve core drive unit 67c includes: a solenoid 67b; and a frame 121, which moves back and forth by means of the solenoid 67b.

[0191] The frame 121 includes: a pressure regulating valve operating part 122, which moves the valve stem 67d and the valve core 67a back and forth by means of a follower 67da; and a clamping action limiting part 123, which limits the movement of the clamping member that locks the cover 26, which is part of the cover locking mechanism 72 and closes the main body 23, or releases the restriction on movement.

[0192] The pressure regulating valve operating part 122 has a pair of cam surfaces 122a and 122b, which each have: a first straight portion that is away from the pressure regulating hole 81; a second straight portion that is close to the pressure regulating hole 81; and an inclined portion that is inclined relative to the reciprocating movement direction driven by the solenoid 67b, and connects the first straight portion and the second straight portion.

[0193] Here, the position where the solenoid 67b pushes the frame 121 out is called the forward position (first position) of the frame 121, and the position where the solenoid 67b pulls the frame 121 in is called the backward position (second position) of the frame 121. When the frame 121 moves to the forward position, a pair of cam surfaces 122a and 122b causes the follower 67da to move away from the pressure regulating hole 81, thereby opening the pressure regulating hole 81. When the frame 121 moves to the backward position, a pair of cam surfaces 122a and 122b causes the follower 67da to move closer to the pressure regulating hole 81, thereby closing the pressure regulating hole 81.

[0194] The driving force for opening the pressure regulating valve 67 is transmitted from the solenoid 67b to the valve stem 67d primarily through the contact between the cam surface 122a, which is away from the pressure regulating port 81, and the cam follower surface 67db. The driving force for closing the pressure regulating valve 67 is transmitted from the solenoid 67b to the valve stem 67d primarily through the contact between the cam surface 122b, which is close to the pressure regulating port 81, and the cam follower surface 67dc.

[0195] The distances between the first straight section and the inner cover 61, and the distances between the second straight section and the inner cover 61, correspond to the length and elastic force of the elastic body 67dd that applies a compressive load in a manner that separates the valve core 67a and the valve stem 67d from each other. Furthermore, the distances between the first straight section and the inner cover 61, and the distances between the second straight section and the inner cover, can also be set as the distance between the first straight section and the second straight section in the out-of-plane direction of the inner cover 61.

[0196] For example, the separation distance between the first straight section and the inner cover 61 is set in such a way that when the frame 121 is in the forward position, even if the internal pressure of the pot 25 and the pressure acting on the gasket 67ab are in a depressurization state such as 0.8 atmospheres to 0.4 atmospheres, the valve core 67a can be given a force by means of the elastomer 67dd that overcomes the internal pressure of the pot 25 and causes the gasket 67ab to separate from the inner cover 61.

[0197] The separation distance between the second straight section and the inner cover 61 is set as follows: With the frame 121 in the retracted position, and the pressure acting on the gasket 67ab as the internal pressure of the pot 25 exceeds a set pressure, for example, 20 kPa, the gasket 67ab is pressed against the inner cover 61, thus closing the pressure regulating port 81. Furthermore, the separation distance between the second straight section and the inner cover 61 is set as follows: When the frame 121 is in the retracted position and the internal pressure of the pot 25 exceeds the set pressure, the valve core 67a overcomes the elastic force acting from the elastic body 67dd and is pressed upwards by the internal pressure of the pot 25, causing the gasket 67ab to separate from the inner cover 61 and opening the pressure regulating port 81. The set pressure is also called the opening pressure.

[0198] However, when the internal pressure of the pot 25 is increased to a level higher than atmospheric pressure, steam flows out of the pressure regulating hole 81 immediately after the pressure regulating valve 67 is opened. The higher the steam outflow velocity at this time, the greater the likelihood that foreign objects such as food scraps will be sucked in and adhere to the pressure regulating hole 81. Conversely, when the internal pressure of the pot 25 decreases compared to atmospheric pressure, gas flows into the pot 25 and is blown towards the food being cooked immediately after the pressure regulating valve 67 is opened. The higher the gas outflow velocity at this time, the greater the likelihood that foreign objects such as food scraps will be lifted by the inflowing gas and adhere to the inner surface of the inner lid 61, thus hindering proper cooking. To reduce the steam outflow velocity and the gas inflow velocity, a larger opening area of ​​the pressure regulating hole 81 is required.

[0199] On the other hand, when the internal pressure of the pot 25 decreases compared to atmospheric pressure, the gasket 67ab of the pressure regulating valve 67 adheres to the pressure regulating hole 81, thus sealing the pressure regulating hole 81. Considering the sealing performance of the valve, the gasket 67ab is preferably made of a soft material such as silicone resin or silicone rubber. Alternatively, the sealing surface of the gasket 67ab made of such material may be strongly adhered to the upper surface of the inner cover 61 due to the negative pressure inside the pot 25, or the central part may be deformed relative to the annular protrusion provided on the outer periphery of the gasket 67ab in order to improve the sealing performance, so that the central part is strongly adhered to the pressure regulating hole 81.

[0200] That is, if the opening area of ​​the pressure regulating hole 81 is further increased in order to reduce the outflow velocity of steam and the inflow velocity of gas, then if the internal pressure per unit area is constant, the force acting on the sealing surface of the gasket 67ab during pressure reduction and the expansion of the sealing surface area will increase accordingly.

[0201] Therefore, as Figure 9 and Figure 10 As shown, the pressure regulating hole 81 is preferably an opening group having a plurality of fine holes 81a. For example, the pressure regulating hole 81 is an opening group including two semi-circular openings facing each other, and has a non-opening portion mounted in the center. Figure 13 (The cross-sectional position in the middle). Preferably, the non-opening portion is configured to: prevent deformation of the central portion of the sealing surface near the center of the gasket 67ab, that is, the portion that is closest to the pressure regulating hole 81 due to the negative pressure inside the pot 25, and prevent the gasket 67ab from sticking to the pressure regulating hole 81. This pressure regulating hole 81 can simultaneously prevent the reduction of steam outflow velocity and gas inflow velocity, as well as the sticking of the sealing surface during pressure reduction.

[0202] Figure 14 This is an enlarged cross-sectional view of the safety valve of the rice cooker involved in this embodiment.

[0203] exist Figure 12 On the basis of Figure 14As shown, the safety valve 97 of the rice cooker 1 according to this embodiment is a valve portion 117 provided on the lid 26. The safety valve 97 includes a valve core 97a, which allows the flow of gas between the inner and outer sides of the pot 25 by opening the high-pressure exhaust port 82 of the inner lid 61, and cuts off the flow of gas between the inner and outer sides of the pot 25 by closing the high-pressure exhaust port 82 of the inner lid 61.

[0204] If the internal pressure of the pot 25 exceeds the specified pressure, the safety valve 97 opens the high-pressure vent 82. For example, if a foreign object adheres to the pressure regulating port 81, causing the internal pressure of the pot 25 to exceed the specified pressure, the safety valve 97 opens the high-pressure vent 82 to reduce the internal pressure of the pot 25. If the internal pressure of the pot 25 is below the specified pressure, the safety valve 97 preferably returns the high-pressure vent 82 to the closed state. Therefore, the safety valve 97 includes: a valve core retaining cylinder portion 97b, which is disposed on the outer cover 56 and defines a cylindrical space; a valve cover portion 97c, which is integrally disposed with the valve core support portion 67e of the pressure regulating valve 67 and closes the valve core retaining cylinder portion 97b; a valve core 97a, which is supported on the valve core retaining cylinder portion 97b and the valve cover portion 97c in a reciprocating manner; and an elastic body 97d, which is located between the valve core retaining cylinder portion 97b and the valve core 97a and generates a force that presses the valve core 97a against the upper surface of the inner cover 61.

[0205] If the internal pressure of the pot 25 after the inner cover 61 is closed exceeds the specified pressure, the valve core 97a causes the high-pressure exhaust port 82 to open. The valve core 97a includes: a valve core base 97aa, which is supported on the valve core retaining cylinder 97b in a reciprocating manner; and a gasket 97ab, which is disposed at the end of the valve core base 97aa.

[0206] Elastomer 97d is, for example, a helical spring.

[0207] Figure 15 This is a perspective view of the gasket of the safety valve of the rice cooker according to this embodiment.

[0208] like Figure 14 and Figure 15 As shown, if the inner cover unit 59 is assembled onto the cover body 26, the gasket 97ab of the safety valve 97 of the rice cooker 1 according to this embodiment contacts the upper surface of the inner cover 61, thereby sealing the high-pressure exhaust port 82. The gasket 97ab may have a planar shape that makes surface contact with the upper surface of the inner cover 61, but it may also have an annular protrusion that makes line contact with the upper surface of the inner cover 61 in a manner that surrounds the high-pressure exhaust port 82. The gasket 97ab, which makes line contact with the upper surface of the inner cover 61 in a manner that surrounds the high-pressure exhaust port 82, does not contact the upper surface of the inner cover 61 on one side, thus reliably closing the high-pressure exhaust port 82.

[0209] The high-pressure exhaust port 82 is connected to the steam exhaust path 66, just like the pressure regulating port 81. Gas flowing out of the boiler space through the high-pressure exhaust port 82 is discharged from the steam port 65 via the steam exhaust path 66.

[0210] Preferably, the high-pressure exhaust port 82 is located away from the pressure regulating port 81. That is, preferably, the safety valve 97 that opens and closes the high-pressure exhaust port 82 is also located away from the pressure regulating valve 67. As a result, the rice cooker 1 can reduce the possibility that both the pressure regulating port 81 and the high-pressure exhaust port 82 may be blocked by foreign objects such as mucus or food mixed with rice.

[0211] Furthermore, assuming that the pressure regulating port 81 is blocked by foreign objects or the solenoid 67b malfunctions, the function of the pressure regulating valve 67 in opening the pressure regulating port 81 is lost. In this case, if the internal pressure of the boiler 25 reaches an abnormal pressure (specified pressure) exceeding the set pressure, the safety valve 97 opens the high-pressure exhaust port 82. The specified pressure at which the safety valve 97 opens the high-pressure exhaust port 82 is, for example, 26 kPa, and the set pressure at which the pressure regulating valve 67 opens the pressure regulating port 81 is, for example, set to be greater than 20 kPa. Therefore, when an abnormality is caused by the discharge of steam through the pressure regulating port 81 and the internal pressure of the boiler 25 is abnormal, the safety valve 97 opens the high-pressure exhaust port 82.

[0212] However, if the high-pressure vent 82 is blocked by foreign objects, the safety valve 97 may lose its function. If both the pressure regulating port 81 and the safety valve 97 fail to function simultaneously, the internal pressure of the pot 25 may reach a pressure exceeding the intended pressure. Therefore, even if both the pressure regulating port 81 and the safety valve 97 fail to function simultaneously, the lid gasket 62 of the inner lid unit 59 serves as a safety device to allow the internal pressure of the pot 25 to escape. However, assuming that the lid gasket 62 functions in a way that allows the internal pressure of the pot 25 to escape, the lid gasket 62 remains in a state of allowing the internal pressure of the pot 25 to escape and does not automatically return to a state of closing the internal space of the pot. As a result, the rice cooker 1 cannot control the internal pressure of the pot 25, and may not be able to perform proper cooking.

[0213] Therefore, the rice cooker 1 according to this embodiment has a blockage prevention part 125, which protrudes into the inside of the pot 25 closed by the inner lid 61 through the high pressure exhaust port 82 to prevent the cooked food, which is a foreign object, from blocking the high pressure exhaust port 82.

[0214] Immediately after the safety valve 97 opens the high-pressure vent 82, steam inside the pot 25 flows rapidly toward the high-pressure vent 82. This rapid steam flow may cause the cooked food, which is a foreign object, to be thrown toward the high-pressure vent 82. Therefore, preferably, the anti-blocking part 125 protrudes through the high-pressure vent 82 toward the inside of the pot 25 with the inner lid 61 closed, in a manner that prevents the high-pressure vent 82 from being blocked regardless of whether the safety valve 97 opens or closes it.

[0215] Furthermore, if the high-pressure exhaust port 82 can be prevented from being blocked when the safety valve 97 opens, the blocking part 125 will not hinder the function of the safety valve 97. In other words, when the safety valve 97 closes the high-pressure exhaust port 82, the function of the safety valve 97 may not be lost regardless of whether foreign objects block the high-pressure exhaust port 82. Therefore, the blocking part 125 can only protrude into the inside of the pot 25 with the inner cover 61 closed when the safety valve 97 opens the high-pressure exhaust port 82.

[0216] An anti-blocking portion 125 is disposed on the valve core 97a of the safety valve 97. Preferably, the anti-blocking portion 125 is integrally formed with the gasket 97ab of the valve core 97a. The anti-blocking portion 125 may be disposed on the valve core base 97aa of the valve core 97a and pass through the gasket 97ab. The anti-blocking portion 125, which is integrally formed with the valve core 97a, can reduce the structural complexity of the safety valve 97 and can prevent a decrease in the reliability of the opening and closing action of the safety valve 97 and the sealing performance of the safety valve 97. In addition, the anti-blocking portion 125 may be disposed on the valve core retaining sleeve portion 97b and pass through the entire valve core 97a. In other words, the anti-blocking portion 125 may be integrated with the valve core 97a in a manner that follows the reciprocating movement of the valve core 97a, or it may be a non-moving, i.e., fixed structure disposed in the valve box equivalent to the safety valve 97 and not follow the valve core 97a.

[0217] Generally, the inner cover unit 59 is assembled onto the cover 26 by tracing an arc-shaped trajectory with the hinge mechanism 27 located near the cover 26 and the fulcrum of the interlocking joint centered thereon, such that the angle between the cover 26 and the inner cover unit 59 is close to 0 degrees. Therefore, it is preferable that the anti-blocking portion 125 has a conical shape that tends towards the protruding end 125a and tapers at the end. This shape of the anti-blocking portion 125 does not contact the opening edge of the high-pressure vent 82 and can smoothly pass through the high-pressure vent 82 to the inner space of the pot, while ensuring a longer protruding length of the inner space of the pot. This is because, assuming that the anti-blocking portion 125 is a cylinder with the same diameter as the opening diameter of the high-pressure vent 82, the inner cover unit 59 must be assembled by linear movement relative to the cover 26, and the anti-blocking portion 125 would block the high-pressure vent 82, causing the safety valve 97 to lose its function. Therefore, the conical shape of the anti-blocking portion 125 has an extremely effective shape.

[0218] Furthermore, the anti-clogging part 125 has a hemispherical protruding end 125a disposed within the pot's interior space. The anti-clogging part 125 is exposed to high-temperature steam during the cooking process of the rice cooker 1. Therefore, by pre-forming the protruding end 125a of the anti-clogging part 125 into a hemispherical shape, for example, a hemispherical shape with a diameter of approximately 1 mm, heat-induced deterioration of the anti-clogging part 125 can be suppressed. For example, when the anti-clogging part 125 is integrally molded with the gasket 97ab, the anti-clogging part 125 can be integrally molded using the same raw material as the gasket 97ab. When the gasket 97ab is generally made of rubber or silicone resin with rubber-like properties, so-called silicone rubber, pre-forming the protruding end 125a of the anti-clogging part 125, which is integrally molded using the aforementioned raw material, into a hemispherical shape can suppress heat-induced deterioration. This also applies when the anti-clogging part 125 is integrally molded with the synthetic resin lid 26. Furthermore, when the lid 26 is opened, the protruding end 125a of the plug 125 is prevented from being exposed in the inner lid 61, which is fully visible to the user along with the opening of the pot 25. In terms of appearance, it is also preferable to pre-arrange the tip of this part with a curve.

[0219] The rice cooker 1 has multiple valve sections 117, namely a safety valve 97 and a pressure regulating valve 67. If the anti-blocking part 125 is provided in the safety valve 97, the possibility of the rice cooker 1 losing its function of controlling the internal pressure of the pot 25 is extremely low. On the other hand, the rice cooker 1 can also have an anti-blocking part 125 in the pressure regulating valve 67. As a result, the rice cooker 1 can increase the probability of performing a good cooking operation.

[0220] The rice cooker 1 can open the pressure reducing valve 70 when the pressure regulating valve 67 and safety valve 97 are closed, i.e., when the steam exhaust path 66 is closed. This allows the pressure reducing pump 68 to activate and reduce the internal pressure of the pot 25 to below atmospheric pressure. When the internal pressure of the pot 25 drops to a negative pressure below atmospheric pressure, the pressure regulating valve 67 and safety valve 97 close due to the negative pressure inside the pot 25, and the pressure reducing valve 70 also closes. This maintains the internal pressure of the pot 25 at a reduced pressure even when the pressure reducing pump 68 stops activating. Furthermore, when the internal pressure of the pot 25 is in a reduced pressure state, the pressure reducing valve 70 can be closed, stopping the pressure reducing pump 68, and the internal pressure of the pot 25 can be restored to atmospheric pressure by opening the pressure regulating valve 67.

[0221] However, during the heat preservation process, the internal pressure of the pot 25 sometimes becomes depressurized. When the lid 26, which is in a depressurized state, is opened, the pressure regulating valve 67 is opened, allowing the internal pressure of the pot 25 to return to atmospheric pressure. As a result, the force required to open the closed lid 26 is significantly reduced. Furthermore, the heat preservation process performed immediately after the cooking action, as well as the heat preservation process performed independently, are collectively referred to as the "heat preservation action".

[0222] However, if the heat preservation action under reduced pressure continues for a long time, the lid gasket 62 is pressed forcefully by the flange portion 32 of the pot 25, and the suction cup portion 88 of the lid gasket 62 is in strong contact with the pot 25. Therefore, even if the internal pressure of the pot 25 is restored to atmospheric pressure, the lid gasket 62 may not easily detach from the flange portion 32 of the pot 25.

[0223] Figure 16 This is a control block diagram of the rice cooker according to an embodiment of the present invention.

[0224] like Figure 16 As shown, the rice cooker 1 according to this embodiment enables the input / output control circuit board 75 and the heating control circuit board 42 to cooperate in performing operations. The input / output control circuit board 75 and the heating control circuit board 42 input and output control signals to each other bidirectionally. The input / output control circuit board 75 outputs a heating control signal to the heating control circuit board 42, and the heating control circuit board 42 outputs a display control signal to the input / output control circuit board 75.

[0225] In addition, the rice cooker 1 includes: a coil drive circuit 151 that energizes the heating coil 31; a lid heater drive circuit 153 that energizes the lid heater 58; a lid temperature sensor 155 that detects the temperature of the inner lid 61; a lid opening / closing sensor 156 that is located inside the lid body 26 and monitors the opening and closing of the lid body 26; a pressure sensor 157 that detects the internal pressure of the pot 25; an inner lid mounting sensor 99; and a notification unit 158.

[0226] The coil drive circuit 151 includes: a first drive circuit 151u, which energizes a first coil 31u with a high-frequency current based on a first heating control signal output from the heating control circuit board 42; and a second drive circuit 151d, which energizes a second coil 31d with a high-frequency current based on a second heating control signal output from the heating control circuit board 42. The two coil drive circuits 151u and 151d are, for example, at least one of a power supply circuit, an inverter, an IH (Induction Heating) drive circuit, and a switching element. The coil drive circuit 151 causes the output of the two coils 31u and 31d to increase or decrease by varying at least one of the period of the high-frequency current energizing the two coils 31u and 31d and the duty cycle of the energizing time.

[0227] Furthermore, for ease of explanation, the rice cooker 1 is assumed to have a switching element that selectively energizes one of the two coils 31u and 31d. The rice cooker 1 can be configured to energize both coils 31u and 31d simultaneously. That is, there can be a period during which both coils 31u and 31d are energized simultaneously.

[0228] The lid heater drive circuit 153 powers the lid heater 58 with DC or AC current based on the lid heating control signal output by the heating control circuit board 42.

[0229] The cover temperature sensor 155 is a thermistor. The cover temperature sensor 155 monitors the temperature of the heat sink 57. The monitored temperature of the cover temperature sensor 155, i.e., the temperature of the heat sink 57, is related to the temperature of the inner cover 61. That is, the temperature of the inner cover 61 can be inferred from the monitored temperature of the cover temperature sensor 155. The temperature of the inner cover 61 inferred from the temperature detected by the cover temperature sensor 155 will be referred to as the "cover temperature". The cover temperature detected by the cover temperature sensor 155 is specifically used for managing the heating temperature of the inner cover 61 based on the cover heater 58.

[0230] Preferably, the cover opening / closing sensor 156 is positioned near the hinge mechanism 27. The cover opening / closing sensor 156 can be any type of sensor, such as optical, mechanical, or magnetic, as long as it can output a monitoring signal based on the opening / closing of the cover 26 to the input / output control circuit board 75. For example, if the cover 26 is open and tilted relative to the main body 23, the cover opening / closing sensor 156 monitors the tilting posture of the cover 26. Conversely, if the cover 26 is closed, the cover opening / closing sensor 156 monitors the posture of the cover 26.

[0231] Pressure sensor 157 is located inside the cover 26 and monitors the pressure on the side of the pot 25 that is closer to the pressure regulating valve 67 of the steam exhaust path 66, which is equivalent to the internal pressure of the pot 25, and outputs it to the heating control circuit board 42. Pressure sensor 157 may also be omitted.

[0232] The inner cover assembly sensor 99 is a mechanical switch that is pressed in when the inner cover unit 59 is assembled onto the cover body 26 and protrudes when the inner cover unit 59 is removed from the cover body 26. The inner cover assembly sensor 99 monitors the presence or absence of the inner cover unit 59 and outputs this information to the heating control circuit board 42.

[0233] The notification unit 158 ​​is at least one of the following structures: a light source that illuminates or flashes, such as a lamp or a light-emitting diode (LED), which depends on the user's vision; a sound generator that emits electrically synthesized speech, buzzing sounds, etc., which depends on the user's hearing; and a vibrator, which depends on the user's touch.

[0234] The input / output control circuit board 75 receives operation signals from the buttons on the operation unit 77 and display control signals from the heating control circuit board 42. Based on these inputs, the input / output control circuit board 75 controls the display operation of the display unit 76, controls the operation of the notification unit 158, and outputs heating control signals to the heating control circuit board 42.

[0235] The microprocessor of the input / output control circuit board 75 functions as the following components by executing a predetermined program: an input signal generation unit 162 that generates control signals corresponding to the operation signals output by each key element; a display control unit 163 that controls the display operation of the display unit 76; and a condition setting unit 165 that can prompt, select, and set various conditions for key element selection in cooperation with the input signal generation unit 162 and the display control unit 163.

[0236] The condition setting unit 165 can, for example, prompt multiple processes in sequence, including the cooking process, the boiling process, and the cleaning process, and select and set the desired process.

[0237] The input / output control circuit board 75 stores, for example, the cooking process corresponding to various conditions selectable via buttons, such as rice brand, cooking method, and hardness. The display unit 76 displays the various conditions of the process stored in the storage unit and, by accepting the operation of the operation unit 77 to select the above conditions, appropriately selects and sets the process.

[0238] The heating control circuit board 42 of the main body 23 adjusts the heating coil 31 and the lid heater 58 during cooking and heat preservation based on the bottom temperature of the pot detected by the pot temperature sensor 46 and the lid temperature detected by the lid temperature sensor 155, thereby controlling the temperature of the pot 25 and the inner lid 61.

[0239] The inputs of the heating control circuit board 42 are the temperature monitoring signal output by the pot temperature sensor 46, the temperature monitoring signal output by the lid temperature sensor 155, the internal pressure monitoring signal output by the pressure sensor 157, the lid opening and closing monitoring signal output by the lid opening and closing sensor 156, and the heating control signal output by the input / output control circuit board 75.

[0240] Based on the above inputs, the heating control circuit board 42 controls the heating coil 31 that heats the pot 25 and the lid heater 58 that heats the inner lid 61 during cooking and heat preservation, respectively. The heating control circuit board 42 primarily controls the heating coil 31 based on the temperature monitoring signal output from the pot temperature sensor 46, thereby managing the temperature of the bottom of the pot 25. The heating control circuit board 42 primarily controls the lid heater 58 based on the temperature monitoring signal output from the lid temperature sensor 155, thereby managing the temperature of the inner lid 61.

[0241] In addition, the heating control circuit board 42 controls the opening and closing of the pressure regulating valve 67 of the steam discharge path 66, the pressure reducing action of the pressure reducing pump 68, and the lid locking action of the lid locking mechanism 72 based on the internal pressure monitoring signal output by the pressure sensor 157.

[0242] The microprocessor of the heating control circuit board 42 functions as the cooking control unit 167 and the heat preservation control unit 168 by executing a prescribed program.

[0243] If the operation unit 77 is input to start cooking, the cooking control unit 167 sequentially executes the soaking process, the boiling heating process, the boiling continuous process, and the simmering process to cook the rice. Alternatively, if the operation unit 77 is input to start cooking, the cooking control unit 167 sequentially executes the cooking process.

[0244] The heat preservation control unit 168 performs the heat preservation process. The heat preservation process performs a simple heat preservation process to keep the rice in the pot 25 at a specified heat preservation temperature, and a reheating heat preservation process to reheat the rice in the pot 25 that is below the specified heat preservation temperature to the specified heat preservation temperature.

[0245] The storage device of the heating control circuit board 42 stores various combinations of pressure increase and decrease types of the driving timing of the pressure regulating valve 67 and the pressure reducing pump 68, as well as the energizing types of the first coil 31u and the second coil 31d, and the combinations of the above-mentioned execution timing in each process.

[0246] The states of rice cooker 1 include, for example, "waiting without any processing," "additional soaking" (soaking excess rice in water), "cooking" (cooking rice and water to make cooked rice), "keeping warm" (maintaining the temperature of the rice), and "reservation" (waiting until the set time to start cooking). Any of the states that rice cooker 1 is in—waiting, adding soak, cooking, keeping warm, or reservation—are included in the current state of rice cooker 1.

[0247] Next, we will explain an example of the cooking process of rice cooker 1, that is, the cooking action.

[0248] Place the food to be cooked into the pot 25. Next, house the pot 25 containing the food to be cooked into the pot housing section 21 of the main body 23 and close the lid 26.

[0249] If the power plug of rice cooker 1 is plugged into a commercial AC power outlet, rice cooker 1 will start in its initial state before cooking or keeping warm. The initial state is also called the waiting state or the stopped state.

[0250] Whenever a button on the operation unit 77 is operated in the initial state, an operation signal corresponding to the operated button is input to the input signal generation unit 162. The condition setting unit 165, in cooperation with the input signal generation unit 162, changes the cooking process settings and, in cooperation with the display control unit 163, displays the changed settings on the display unit 76. The display unit 76 provides a visual prompt to the user of the rice cooker 1 regarding the current cooking process settings corresponding to the operated button.

[0251] If a button element corresponding to the cooking process decision is operated, the operation signal corresponding to the cooking process decision is input to the input signal generation unit 162. The condition setting unit 165 stores the cooking process displayed on the display unit 76 in the storage device and outputs the heating mode corresponding to the selected cooking process to the heating control circuit board 42.

[0252] The cooking control unit 167 of the rice cooker 1 according to this embodiment executes cooking actions including a soaking process, a boiling heating process, a boiling continuous process, and a simmering process according to the heating mode corresponding to the selected cooking process, thereby cooking the food into rice. Furthermore, the control of each process is referred to by its name. For example, the control of the soaking process is called soaking control.

[0253] The soaking and cooking process includes a preheating process, a cooking quantity determination process, and a soaking process to promote water absorption by the rice in the food being cooked. In addition, sometimes the entire soaking and cooking process is referred to as the soaking process in a broad sense, while the soaking process within the soaking and cooking process is referred to as the soaking process in a narrow sense.

[0254] If the soaking and boiling process begins, the cooking control unit 167 activates the pressure reducing pump 68, pressure reducing valve 70, and pressure regulating valve 67 in a manner that temporarily reduces the internal pressure of the pot 25 and then restores it to atmospheric pressure before returning it to a pressure reducing state.

[0255] First, the cooking control unit 167 activates the solenoid 67b to close the steam discharge path 66 using the pressure regulating valve 67, opens the pressure reducing valve 70 to allow the flow of gas in the path connecting the pot 25 and the pressure reducing pump 68, and activates the pressure reducing pump 68 to discharge the gas in the pot 25.

[0256] Next, the cooking control unit 167 activates the solenoid 67b to open the steam exhaust path 66 using the pressure regulating valve 67, connecting the inside of the pot 25 to the outside of the rice cooker 1. As a result, external gas flows into the pressure-reduced pot 25 through the steam exhaust path 66 and the steam port 65, restoring the internal pressure of the pot 25 to atmospheric pressure. Then, the cooking control unit 167 activates the solenoid 67b to close the steam exhaust path 66 using the pressure regulating valve 67, opens the pressure reducing valve 70 to allow gas flow through the path connecting the pot 25 to the pressure reducing pump 68, and activates the pressure reducing pump 68 to expel the gas from the pot 25.

[0257] That is, when the soaking and cooking process begins, the internal pressure of the pot 25 changes. The change in internal pressure of the pot 25 forces the air inside the rice out of the rice and replaces the squeezed air, allowing water to penetrate to the center of the rice.

[0258] Whenever the internal pressure of the pot 25 decreases compared to atmospheric pressure, the display control unit 163 illuminates the LED directly below the string "vacuum". Whenever the internal pressure of the pot 25 returns to atmospheric pressure, the display control unit 163 turns off the LED directly below the string "vacuum".

[0259] The start of the soaking and cooking process also marks the start of the cooking quantity determination process. The cooking control unit 167 uses the heating coil 31 to heat the pot 25, causing the lid temperature sensor 155 to monitor the temperature change of the pot 25, and determines the cooking quantity based on the temperature change of the pot 25. In addition, the temperature of the pot 25 is affected by the temperature of the rice, the temperature of the water, and the temperature of the atmosphere in the rice cooker 1, and is usually represented by the temperature of the food being cooked.

[0260] If the cooking quantity determination process ends, the cooking control unit 167 initiates the soaking process. The cooking control unit 167, performing the soaking process, energizes the heating coil 31 to heat the pot 25. The energizing type applied to the soaking process can be a specific energizing type independent of the cooking quantity determined in the cooking quantity determination process, or it can be an energizing type selected from multiple cooking types based on the output of the heating coil 31 and the energizing time, or it can be an energizing type corrected for the specific energizing type based on the cooking quantity.

[0261] Furthermore, the cooking control unit 167 energizes or de-energizes the heating coil 31 during the entire soaking and cooking process in a manner that prevents the temperature of the pot 25 from exceeding 60 degrees Celsius. As a result, the rice cooker 1 can prevent the rice from becoming gelatinized during the soaking process and avoids deterioration in the cooking of the rice.

[0262] If the soaking time ends, the cooking control unit 167 will initiate the boiling heating process.

[0263] During the boiling heating process, the cooking control unit 167 energizes the heating coil 31 until the food being cooked is detected to have boiled. The cooking control unit 167 heats the food in the pot 25 more intensely than in the boiling process, causing the temperature of the food to rise to the boiling temperature in a short time. The cooking control unit 167 closes the pressure reducing valve 70, stops the pressure reducing pump 68, and opens the pressure regulating valve 67. As a result, the internal pressure of the pot 25 immediately returns to atmospheric pressure. The display control unit 163 turns off the LED located directly below the string "vacuum".

[0264] Regarding the type of energization used to bring the food to a boil, it is preferable to sequentially perform energization of the first coil 31u, a period without energization, energization of the second coil 31d, and a period without energization. Furthermore, it is preferable that the cooking control unit 167 adjusts the energization time of the heating coil 31 according to the cooking amount. For example, the energization time of the second coil 31d can be adjusted inversely to the cooking amount, the energization time of the first coil 31u can be set in a manner proportional to the cooking amount, and the repetition interval of the energization type, i.e., the cycle of the energization type, can be set in a manner proportional to the cooking amount.

[0265] Then, if the temperature at the bottom of the pot 25 reaches a predetermined temperature, for example, 90 degrees Celsius or higher, and the temperature at the inner lid 61 also reaches a predetermined temperature, for example, 90 degrees Celsius or higher, the cooking control unit 167 opens the pressure regulating valve 67 and begins monitoring the boiling of the food under atmospheric pressure. The display control unit 163 illuminates the LED located directly below the "Pressure" string based on the internal pressure of the pot 25 monitored by the pressure sensor 157. The cooking control unit 167 monitors the rate of temperature rise per unit time at the bottom of the pot 25 or the rate of temperature rise per unit time at the inner lid 61. If the rate of temperature rise is below a predetermined rate of rise, it determines that the food has boiled.

[0266] The type of electricity used to determine whether the food being cooked has boiled is different from the type of electricity used to bring the food to a boil. Furthermore, preferably, the cooking control unit 167 also adjusts the energizing time of the heating coil 31 according to the cooking volume during the boiling determination process.

[0267] In this embodiment, the cooking control unit 167 energizes the heating coil 31 with various different energizing types during the boiling heating process, and further energizes the heating coil 31 with different energizing types during the boiling determination process. That is, the rice cooker 1 reduces uneven cooking of rice by extremely carefully changing the appropriate energizing type to make the water contained in the cooked food boil.

[0268] Furthermore, the cooking control unit 167 can select, adjust, or change the power supply type according to the amount of rice to be cooked. As a result, the rice cooker 1 uses the power supply type that is appropriate for the amount of rice to be cooked in a very precise manner, thereby reducing uneven cooking of the rice.

[0269] If the boiling heating process ends, the cooking control unit 167 causes the process to enter the boiling continuous process.

[0270] During the continuous boiling process, the cooking control unit 167 switches the power supply to the heating coil 31 while the pressure regulating valve 67 is closed, thereby maintaining the temperature of the bottom of the pot 25 at or above a specified temperature, for example, 98 degrees Celsius, and continuously powers the lid heater 58 to maintain the temperature of the inner lid 61 at or above a specified temperature, for example, 98 degrees Celsius.

[0271] If the food being cooked continues to boil, the steam generated from the food fills the space inside the pot, causing the internal pressure of the pot 25 to rise. If the internal pressure of the pot 25 rises above the set pressure, the gasket 67ab of the pressure regulating valve 67 is pressed upward against the elastic force acting on the elastic body 67dd, opening the pressure regulating port 81. The steam inside the pot 25 flows out through the steam discharge path 66 and is discharged to the outside of the rice cooker 1 through the steam port 65. If the internal pressure of the pot 25 decreases below the set pressure due to the steam discharge, the gasket 67ab closes the pressure regulating port 81 using the elastic force acting on the elastic body 67dd. In this way, during the continuous boiling process, the pressure regulating valve 67 intermittently opens and closes the pressure regulating port 81.

[0272] Assuming the pressure regulating port 81 is blocked by a foreign object, the pressure regulating valve 67 cannot open it. In this case, steam generated from the cooked food further fills the pot's interior, causing the internal pressure of the pot 25 to rise further. If the internal pressure of the pot 25 reaches the specified pressure, the gasket 97ab of the safety valve 97 overcomes the elastic force exerted by the elastomer 97d and is pressed upwards, opening the high-pressure exhaust port 82. Steam inside the pot 25 flows out through the steam exhaust path 66 and is discharged to the outside of the rice cooker 1 through the steam port 65. If the internal pressure of the pot 25 decreases below the specified pressure due to the steam outflow, the gasket 97ab closes the high-pressure exhaust port 82 using the elastic force exerted by the elastomer 97d.

[0273] If the temperature of the pot 25 reaches or exceeds a predetermined temperature, or reaches or exceeds a predetermined rate of temperature increase, for example, by reaching or exceeding a predetermined rate of temperature increase of 0.5 degrees Celsius within 10 seconds, the cooking control unit 167 determines that the water in the pot 25 is beginning to disappear. Upon determining that the water in the pot 25 is beginning to disappear, the cooking control unit 167 extends the energizing time of the heating coil 31.

[0274] If the temperature rise rate at the bottom of the pot 25 reaches or exceeds the specified rise rate, or reaches the drying temperature that makes the remaining moisture in the pot 25 disappear, such as 120 degrees Celsius, then the cooking control unit 167 determines that the food being cooked is cooked and ends the boiling process.

[0275] If the boiling process ends, the cooking control unit 167 will initiate the braising process.

[0276] During the braising process, the cooking control unit 167 switches the energization of the lid heater 58 on and off based on the lid temperature and prevents condensation on the inner lid 61. Additionally, the cooking control unit 167 manages the temperature of the food being cooked by switching the energization of the heating coil 31 on and off based on the temperature of the pot 25. The braising process continues for a predetermined time.

[0277] If the braising process is completed, the cooking control unit 167 completes the cooking action, and the heat preservation control unit 168 begins the heat preservation process.

[0278] The heating control circuit board 42, upon completion of the cooking process, outputs a display control signal corresponding to the end of the cooking process. The input / output control circuit board 75, having received this display control signal, controls the display operation of the display unit 76, controls the notification operation of the notification unit 158, and notifies the user that the cooking process is complete.

[0279] The heat preservation control unit 168 heats the heating coil 31 until the temperature of the rice drops from the freshly cooked temperature, substantially from 100 degrees Celsius, to the heat preservation temperature, substantially down to 73 degrees Celsius. After the heat preservation temperature stabilizes at 73 degrees Celsius, the heating coil 31 is also heated. The heat preservation control unit 168 adjusts the output of the heating coil 31 in a manner that keeps the temperature of the bottom of the pot 25 constant.

[0280] The rice cooker 1 can also reheat the rice in the pot 25.

[0281] The rice cooker 1 of this embodiment, configured as described above, includes: a drain trough 202 provided along at least a portion of the edge of the recess 55a, which guides liquid into the recess 55a through the gap between the operation panel 73 and the outer cover 55, and the drain trough 201 allows the liquid to flow out into the space defined by the outer cover 55 and the outer cover 56; and a storage section 204 that temporarily stores the liquid flowing from the drain trough 202 into the drain trough 201. Therefore, the rice cooker 1 captures the liquid by the drain trough 202 before it flows towards the center of the recess 55a through the gap between the operation panel 73 and the outer cover 55, and allows the liquid to flow out into the space defined by the outer cover 55 and the outer cover 56 through the storage section 204 and the drain trough 201.

[0282] Next, the rice cooker 1 according to this embodiment includes: a drain tank 202, which is inclined downward from the rear to the front of the outer cover 55; and a storage section 204, of which a plurality of storage sections 204 are arranged at the front of the outer cover 55. Therefore, the rice cooker 1 stores liquid flowing downward from the rear to the front of the outer cover 55 and down the drain tank 202 through the plurality of storage sections 204 without causing the liquid to overflow from the storage section 204, and allows it to flow out through the drain hole 201.

[0283] Furthermore, the rice cooker 1 according to this embodiment includes: a drain tank 202 having multiple downstream ends; and storage sections 204 respectively provided at the multiple downstream ends. Therefore, each storage section 204 stores liquid from the multiple downstream ends of the drain tank 202, thereby preventing liquid from overflowing from the storage section 204 and allowing it to flow out through the drain hole 201.

[0284] Furthermore, the rice cooker 1 according to this embodiment includes: a clamping switch CS, which is an electrical component, is provided on the outer cover 55 and is covered by the operation panel 73; and a storage section 204, which is disposed near the clamping switch CS. Therefore, the storage section 204 stores liquid from the drain tank 202, thereby preventing liquid from entering the clamping switch CS.

[0285] Furthermore, the rice cooker 1 according to this embodiment includes a clamping switch CS as an electrical component, which is a monitoring unit for monitoring the opening and closing of the lid 26. Therefore, liquid can be prevented from entering the clamping switch CS that monitors the opening and closing of the lid 26, thus preventing liquid from entering the interior of the lid 26 from hindering the opening and closing of the lid 26.

[0286] Furthermore, the rice cooker 1 according to this embodiment has a drain hole 201 located downstream of the liquid flow path in the storage section 204. Therefore, the liquid temporarily stored in the storage section 204 will not remain, and the liquid can flow out through the drain hole 201 downstream of the flow path.

[0287] Furthermore, the rice cooker 1 according to this embodiment has a plurality of drain holes 201 provided in the drain tank 202. Therefore, the rice cooker 1 can facilitate the discharge of liquid captured by the drain tank 202 over a wide area of ​​the drain tank 202.

[0288] Furthermore, the rice cooker 1 according to this embodiment has a rib 203 disposed above the drain hole 201 and mounted on the drain trough 202. Therefore, even though the outer cover 55, which is a molded product of synthetic resin, has a side drain hole 201a, the rice cooker 1 can prevent the outer surface of the outer cover 55, which corresponds to the embankment that divides the recessed portion 55a, from tilting towards the inside of the recessed portion 55a, thereby having an outer cover 55 with a desired appearance.

[0289] Furthermore, the rice cooker 1 according to this embodiment has a drainage channel 202, i.e., a narrow drainage channel 202a, laid at least along the portion close to the circuit board receiving recess 55b and recess 55a. Therefore, the rice cooker 1 can simultaneously meet the requirements of miniaturization, improved visual visibility of the display 76, and improved operability of the operation 77, and can reliably prevent malfunctions of the input / output control circuit board 75, which is envisioned to be enlarged, due to liquids such as water.

[0290] Furthermore, the rice cooker 1 according to this embodiment has a drain hole 201, i.e., a side drain hole 201a, located at least near the circuit board receiving recess 55b and recess 55a. Therefore, the rice cooker 1 can reliably prevent the input / output control circuit board 75 from malfunctioning by allowing the liquid captured by the narrow drain groove 202a to flow out extremely quickly into the space defined by the outer cover 55 and the outer cover cover 56 area, thereby ensuring the rapid drainage.

[0291] Therefore, the rice cooker 1 according to the present invention can keep liquid that has entered the interior of the lid 26 from the gap between the operation panel 73, which is the top plate of the lid 26 and the outer cover 55, which is an adjacent component thereto, within a desired range.

[0292] While several embodiments of the present invention have been described, these embodiments are merely illustrative and not intended to limit the scope of the invention. The novel embodiments described above can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The above embodiments and their variations are included in the scope and spirit of the invention, and are also included within the scope of the invention as described in the claims and its equivalents.

Claims

1. A rice cooker, wherein, The rice cooker has the following features: A pot, which is used to hold food being cooked; The main body has a pot receiving section capable of accommodating the pot; and The lid is capable of opening and closing the pot housing. The cover body has: An outer cover that covers the main body while the cover is closed; An outer cover having a recess that opens toward the direction of departure from the main body and covering the outer cover cover; as well as The upper surface panel covers the recessed portion. The outer cover has: a drain groove provided along at least a portion of the edge of the recess and inclined in such a way as to guide the liquid toward a drain hole when liquid seeps into the recess through the gap between the upper surface panel and the outer cover, the drain hole allowing the liquid to flow out into the space defined by the outer cover and the outer cover cover area; and a storage section that temporarily stores the liquid flowing from the drain groove to the drain hole.

2. The rice cooker according to claim 1, wherein, The drainage channel slopes downward from the rear to the front of the outer cover. The storage compartments are arranged in multiple portions at the front of the outer cover.

3. The rice cooker according to claim 2, wherein, The drainage channel has multiple downstream ends. The storage units are respectively located at the plurality of downstream ends.

4. The rice cooker according to claim 1, wherein, The rice cooker includes electrical components, which are disposed on the outer cover and covered by the upper surface panel. The storage unit is located near the electrical components.

5. The rice cooker according to claim 4, wherein, The electrical component is a monitoring unit that monitors the opening and closing of the cover.

6. The rice cooker according to claim 1, wherein, The drain hole is located downstream of the liquid flow path in the storage section.

7. The rice cooker according to claim 1, wherein, Multiple drainage holes are provided inside the drainage channel.

8. The rice cooker according to claim 1, wherein, The rice cooker has a rib, which is positioned above the drain hole and mounted on the drain trough.

9. The rice cooker according to claim 1, wherein, The outer cover has a circuit board receiving recess, which is disposed within the recess and accommodates the input / output control circuit board for mounting the input device and display device. The upper surface panel has: an operation section for the input device; and a perspective window for enabling the display device to perform perspective display. The drainage channel is laid at least along the portion of the circuit board receiving recess and the recessed portion that is close to it.

10. The rice cooker according to claim 9, wherein, The drainage hole is located at least in the area close to the circuit board receiving recess and the recessed portion.

Images