JP2024060149A - Safety valve structure and cooking appliance - Google Patents

Abstract

[Problem] The object of the present invention is to provide a safety valve structure that can improve the ease of maintenance around a protrusion that occurs when the safety valve structure is installed in a housing, as compared to the case where a single cylindrical spiral coil spring or other biasing member is used. [Solution] The safety valve structure SV according to the present invention is a safety valve structure that is installed in a housing so as to be able to close a communication hole OS that connects the internal space and the external space of the housing, and includes a valve body SM and a biasing member SP that, when the internal pressure of the housing becomes equal to or higher than a first threshold value, moves the valve body to open the communication hole by a force opposite to the force that biases the valve body toward the communication hole, thereby connecting the internal space and the external space, and in the natural state of the biasing member, the total height of the biasing member in the biasing direction is smaller than the total width of the biasing member in a direction perpendicular to the biasing direction. [Selected Figure] Figure 9

Description

The present invention relates to a safety valve structure. The present invention also relates to a cooking device equipped with the safety valve structure.

In the past, a warning device for a rice cooker has been proposed, which is characterized in that "a lid is attached to the jar body so that it can be opened and closed, the lid is provided with two steam passages, the first and second, which connect the inside of a pot stored in the jar body with the steam port, a pressure regulating valve device is provided in the first steam passage, and a safety valve device is provided in the second steam passage, and a sound generating means is provided at the outlet of the second steam passage which vibrates in response to steam passing through the outlet" (see, for example, JP 2000-014542 A, etc.).

JP 2000-014542 A

In cooking appliances such as the rice cooker described above, a safety valve structure is provided in the housing. This safety valve structure is mainly composed of a valve body and a biasing member that biases the valve body toward the communication hole, and plays a role in releasing the internal pressure of the housing when the internal pressure of the housing becomes abnormally high. In cooking appliances such as the above, a cylindrical spiral coil spring or the like is often used alone as the biasing member. Such cylindrical spiral coil springs maintain a certain height or more even in a compressed state. For this reason, in cooking appliances such as the above, a relatively large protrusion is formed in the part of the housing where the safety valve structure is provided, making the area near the protrusion difficult to maintain (for example, wiping the area near the protrusion is difficult).

The objective of the present invention is to provide a safety valve structure that can improve ease of maintenance near the protrusions that are created when the valve is installed in the housing, compared to when a single cylindrical spiral coil spring or other biasing member is used.

The safety valve structure according to the present invention comprises:
A safety valve structure provided in a housing so as to be capable of closing a communication hole that communicates an internal space and an external space of the housing,
A valve body,
a biasing member that, when an internal pressure of the housing becomes equal to or greater than a first threshold value, moves the valve body by a force opposite to a force biasing the valve body toward the communication hole, thereby opening the communication hole and connecting the internal space and the external space,
In a natural state of the urging member, the overall height of the urging member in the urging direction is smaller than the overall width of the urging member in a direction perpendicular to the urging direction.

The above configuration makes it possible to minimize the bulge of the convex portion that occurs when the valve is installed in the housing, compared to when a single cylindrical spiral coil spring or other biasing member is used. Therefore, with this safety valve structure, it is possible to improve ease of maintenance near the convex portion, compared to when a single cylindrical spiral coil spring or other biasing member is used. The biasing member may be, for example, a conical spring, a leaf spring, a multiplex arrangement of cylindrical spiral coil springs, a magnet, etc., and the natural state refers to a state in which no force is applied to the biasing member.

In the present invention,
The biasing member is preferably a conical spring.

With the above configuration, the protrusions can be made smaller than when the biasing member is, for example, a cylindrical spiral coil spring. This is because a conical spring can be designed so that the wires in the coil portion do not come into contact with each other as much as possible when compressed (in other words, the coil portion becomes spiral-shaped in a plan view when compressed), making it possible to make the overall height as low as possible when compressed. Therefore, with this safety valve structure, the ease of maintenance near the protrusions can be improved compared to when the biasing member is, for example, a cylindrical spiral coil spring.

In the present invention,
the housing has a biasing member support portion that supports the biasing member,
The biasing member is preferably accommodated between a wall portion of the housing in which the communication hole is formed and the biasing member support portion.

According to the above configuration, the length between the wall portion of the housing where the communication hole is formed and the biasing member support portion can be set to be equal to or less than the total height of the biasing member in its natural state, so that the biasing member can be in its natural state or in its compressed state. Therefore, with this safety valve structure, the biasing member can be maintained in a state where its total height is smaller than its total width.

In the present invention,
the housing further has an accommodation space defined by the biasing member support portion and the wall portion,
It is preferable that the biasing member support portion or the wall portion has a notch formed therein for connecting the accommodation space to the outside.

The above configuration makes it possible to prevent liquids such as water or viscous liquids such as sticky paste from remaining in the storage space as much as possible.

The cooking device according to the present invention comprises:
A container opening upward;
a lid disposed above the container to cover an opening of the container;
a communication hole formed in the lid that communicates a space surrounded by the container and the lid with the outside;
a safety valve structure including a valve body that is provided on the cover body so as to be able to close the communication hole, and a biasing member that, when the internal pressure of the space becomes equal to or higher than a first threshold value, moves the valve body by a force opposite to a force that biases the valve body toward the communication hole, thereby opening the communication hole and connecting the space to the outside,
In a natural state of the urging member, the overall height of the urging member in the urging direction is smaller than the overall width of the urging member in a direction perpendicular to the urging direction.

The above configuration makes it possible to minimize the bulge of the protrusion that occurs when the safety valve structure is provided on the lid, compared to when a single cylindrical spiral coil spring or other biasing member is used in the safety valve structure. Therefore, in this cooker, the ease of maintenance near the protrusion can be improved as much as possible, compared to when a single cylindrical spiral coil spring or other biasing member is used in the safety valve structure. The biasing member can be, for example, a conical spring, a leaf spring, a multiplex arrangement of cylindrical spiral coil springs, a magnet, etc., and the natural state refers to a state in which no force is applied to the biasing member.

Fig. 1 is a perspective view of a rice cooker according to an embodiment of the present invention, in which the lid is shown in a closed state. FIG. 2 is a plan view of a lid according to the embodiment of the present invention. This is a cross-sectional view taken along line AA in FIG. FIG. 4 is a bottom view of the lid and hinge component according to the embodiment of the present invention. FIG. 2 is a perspective view of an inner lid of the lid body according to the embodiment of the present invention. Fig. 6 is an enlarged view of the enclosed portion H in Fig. 5. Note that this drawing shows a state in which the abnormal pressure relief valve is not in operation. 6 is an enlarged view of the enclosed portion H in Fig. 5. Note that this drawing shows a state in which the abnormal pressure relief valve is in operation. FIG. 2 is a plan view of an inner lid of the lid body according to the embodiment of the present invention. This is a cross-sectional view taken along the line BB in Fig. 8. Note that this drawing shows a state in which the abnormal pressure relief valve is not in operation. This is a cross-sectional view taken along the line CC in Fig. 8. Note that this drawing shows a state in which the abnormal pressure relief valve is not in operation. This is a cross-sectional view taken along the line BB in Fig. 8. In this figure, the abnormal pressure relief valve is shown in operation, and the vicinity of the abnormal pressure relief valve is shown in an enlarged manner. This is a cross-sectional view taken along the line CC of Fig. 8. In this figure, the abnormal pressure relief valve is shown in operation, and the vicinity of the abnormal pressure relief valve is shown in an enlarged manner. FIG. 2 is a top perspective view of a valve body of the abnormal pressure relief valve according to the embodiment of the present invention. FIG. 2 is a bottom perspective view of the valve body of the abnormal pressure relief valve according to the embodiment of the present invention.

<Structure of rice cooker according to embodiment of the present invention>
The rice cooker 100 according to the embodiment of the present invention is an induction heating type pressure rice cooker, and as shown in Figures 1 and 2, is mainly composed of a main body 110, an inner pot (not shown), a lid 140, and a hinge part 150. These components will be described in detail below.

1, the main body 110 is mainly composed of a housing 111, an induction heating coil (not shown), a heat retention heater (not shown), a heat insulating material (not shown), a ferrite core (not shown), a center sensor (not shown), a blower fan unit (not shown), a power supply circuit board (not shown), an automatic retractable power cord unit (not shown), and a lever mechanism 119. These components will be described in detail below.

1, the housing 111 is mainly composed of a container 111a, a shoulder member 111c, and a protective frame (not shown), and contains a heat insulating material, a ferrite core, an induction heating coil, a heat retention heater, a center sensor, a blower fan unit, a power supply circuit board, an automatic retractable power cord unit, etc. Each component of the housing 111 will be described in detail below.

1, the housing 111a is mainly formed of a side wall portion 111x and a bottom wall portion (not shown). The side wall portion 111x is a cylindrical surrounding wall portion having a generally rounded rectangular shape in a plan view. The bottom wall portion is a generally rounded rectangular corner dish-shaped portion in a bottom view, and is formed below the side wall portion 111x. An intake port is formed at the rear of the bottom wall portion to draw air from outside the housing 111 into the inside, and an exhaust port is formed at the front of the bottom wall portion to exhaust air from inside the housing 111 to the outside. A blower fan unit is disposed above this intake port. When this blower fan unit is driven, outside air is sucked into the housing 111 through the intake port, and the resulting air flow exhausts the heated air from inside the housing 111 to the outside of the system through the exhaust port.

The shoulder member 111c is a frame having a generally rounded rectangular shape in a plan view, and as shown in FIG. 1, is fitted to the upper side of the side wall portion 111x of the container 111a and covers the edge of the upper opening of the container 111a. A generally circular opening is formed in the shoulder member 111c for inserting the inner pot therethrough. Also, as shown in FIG. 1, a lever mechanism 119 is provided in front of the shoulder member 111c. A protective frame is attached to the underside of the shoulder member 111c.

The protective frame is a member that protects the outer periphery of the inner pot and maintains the shape of the shoulder member 111c. A part of the hinge part 150 is fastened to the rear part of this protective frame. An opening is also formed in the center of the bottom wall of the protective frame to allow a center sensor to pass through.

(2) Induction Heating Coil The induction heating coil is used to induction heat the inner pot and is disposed outside the bottom wall and the lower end of the side wall of the protective frame.

(3) Warmth Heater The warmth heater is a heater for keeping cooked rice warm after cooking, and is disposed outside the inner pot when the inner pot is housed in the protective frame.

(4) Thermal insulation material The thermal insulation material is wrapped around the outer periphery of the protective frame and the outer periphery of the warming heater, and serves to prevent heat generated from the inner pot during cooking from leaking out of the protective frame.

(5) Ferrite Core The ferrite core is a component that prevents the magnetic flux generated when current is passed through the induction heating coil from escaping to the outside, and is disposed around the induction heating coil.

(6) Center Sensor The center sensor is a sensor for detecting the temperature of the bottom of the inner pot and for detecting the presence or absence of the inner pot, and protrudes upward through an opening formed in the center of the bottom wall of the protective frame. The center sensor is biased upward by a biasing member such as a coil spring. In other words, the center sensor is free to appear and disappear in the vertical direction.

(7) Blower Fan Unit The blower fan unit is composed of an axial fan, a heat sink, and the like, and is disposed above the intake port in the bottom wall of the housing 111a of the housing 111, as described above, with the rotation axis of the fan aligned substantially vertically. That is, when the delivery fan in this blower fan unit is driven, outside air is sucked in through the intake port and flows into the housing 111, and is then sent upward. The outside air sent upward is supplied to the power supply circuit board and the like through the heat sink to cool those components and the like.

(8) Power Supply Circuit Board The power supply circuit board is a board that constitutes the power supply circuit, and is equipped with an AC power supply, an inverter, a switching power supply, some heat-generating components, etc. This power supply circuit board is housed in the rear space of the housing 111, and is communicatively connected to the control circuit board of the lid 140.

(9) Automatic Retractable Power Cord Unit The automatic retractable power cord unit is comprised of a power cord and an automatic retracting mechanism (not shown), and is housed in the rear space of the housing 111. The power cord is comprised of an attachment plug PL (see FIG. 1) and an electric wire (not shown). The attachment plug PL is disposed at the tip of the electric wire. The electric wire is wound around the automatic retracting mechanism so as to be freely extensible.

(10) Lever mechanism The lever mechanism 119 is a mechanism for opening and closing the cover 140, and is mainly composed of an opening lever 119a, a stopper (not shown), and a spring member (not shown), and is disposed in front of the shoulder member 111c as described above. The opening lever 119a is a swinging lever for opening the cover 140, and is disposed so as to protrude forward at the front upper end of the housing 111a of the housing 111 as shown in FIG. 1. The opening lever 119a applies a pressing force to the stopper via the spring member. The stopper, to which a pressing force is applied from the opening lever 119a, rotates around its rotation axis. When the user rotates the opening lever 119a downward, the cover 140 is released from the main body 110, and the cover 140 opens.

The stopper is mainly composed of a rotating shaft, a locking portion, and a pressure receiving portion, and is rotatably (swingably) mounted on the housing 111a of the main body 110. The locking portion has a curved tip and is mounted on the upper end side of the stopper. This locking portion locks the claw portion of the claw member NP of the lid body 140 when the lid body 140 is closed.

2. Inner pot The inner pot is a bowl-shaped pot that opens upward, is inserted into the opening of the shoulder member 111c, and is housed in the protective frame with a certain gap. The inner pot is a multi-layer body (clad material) of various aluminum alloys and stainless steel alloys, and can be induction-heated by an induction heating coil. The inner pot may be a clay pot or a metal pot coated with paint containing clay pot powder, and various materials and configurations of the inner pot are not particularly limited and can be used.

3 and 4, the lid body 140 is mainly composed of a lid reinforcement part 141, a claw member NP, an exterior body 142, a group of operation buttons 143, an information display panel DI, a pressure adjusting device 144, a steam processing unit 147, a steam sensor (not shown), a control circuit board (not shown), and an inner lid 146. These components will be described in detail below.

(1) Lid Reinforcement Lid reinforcement 141 is made of polyphenylene sulfide (PPS) or the like, and serves to support parts and members such as the control circuit board, claw member NP, pressure regulator 144, steam processing unit 147, and steam sensor (see FIG. 3). As shown in FIG. 3, a part of hinge part 150 is fastened to the rear end of lid reinforcement 141. This hinge part 150 enables lid 140 to be opened and closed relative to main body 110. As shown in FIG. 3, an inner lid 146 is detachably disposed below lid reinforcement 141.

(2) Claw Member The claw member NP is a member having a pair of claw portions, and is attached to the front end of the cover reinforcement portion 141 (see FIG. 4). As described above, when the cover body 140 is closed, the claw portions of the claw member NP are locked by the locking portion of the stopper of the lever mechanism 119 of the main body 110.

(3) Exterior Body As shown in Figs. 1 to 4, the exterior body 142 is a substantially rectangular parallelepiped member composed of an upper exterior body 142a and a lower exterior body 142b, and houses the lid reinforcement part 141 and the like. The upper exterior body 142a is a substantially rectangular parallelepiped cover member that opens at the bottom, and covers the upper side of the lower exterior body 142b and the like, as shown in Fig. 3. As shown in Figs. 1 to 3, an opening for exposing the top surface of the operation buttons 143 is formed at the front end of the top wall of the upper exterior body 142a, an opening for exposing the top surface of the information display panel DI is formed immediately behind the opening for exposing the operation buttons 143 in the top wall of the upper exterior member 141a, and a steam vent BO for discharging steam generated in the inner pot to the outside is formed at the rear of the top wall of the upper exterior member 141a. The lower exterior body 142b is disposed below the upper exterior body 142a as shown in Fig. 3. A through hole is formed at the front end of the lower exterior body 142b, and the claw portion of the claw member NP is inserted into this through hole (see Fig. 4).

(4) Operation Button Group Operation button group 143 is made up of, for example, buttons for selecting rice cooking methods and the like, and is used to allow the user to select the operation method of rice cooker 100. The upper surface of operation button group 143 is exposed through an opening formed in upper exterior body 142a of exterior body 142, as described above.

1 to 3, the information display panel DI is disposed immediately behind the operation button group 143. In addition, the upper surface of the information display panel DI is exposed through an opening formed in the upper exterior body 142a of the exterior body 142 as described above, and the information display panel DI displays various information such as rice cooking menu information, rice cooking progress information, etc.

(6) Pressure Regulating Device When the lid 140 is closed and pressure cooking is in progress, the pressure regulating device 144 closes the pressure regulating port VO of the inner lid 146 to regulate the pressure inside the inner pot to 1 atmosphere or more (for example, 1.03 to 1.3 atmospheres). In addition, the pressure regulating device 144 regulates the rotation of the lever mechanism 119 of the main body 110 so that the lid 140 does not open during pressure cooking. In this embodiment, the pressure regulating device is not particularly limited, and a conventional pressure regulating device may be used.

(7) Steam Processing Unit The steam processing unit 147 traps the steam rising from the inner pot during cooking and the accumulated sticky rice, and returns it to the inner pot. As described above, it is supported by the lid reinforcement portion 141.

(8) Steam Sensor The steam sensor is a general temperature sensor (e.g., a thermocouple, a thermistor, etc.) for detecting the temperature of steam generated in the inner pot. The steam sensor is supported by the lid reinforcement portion 141 as described above.

(9) Control Circuit Board The control circuit board is a board that constitutes the control circuit, and has electronic components such as a microcomputer mounted thereon, and is communicatively connected to the operation buttons 143, steam sensor, etc., and is communicatively connected to the induction heating coil, heat retention heater, center sensor, blower fan unit, etc. of the main body 110 via the power supply circuit board of the main body 110. The microcomputer is equipped with a memory, and the memory stores various programs and data for executing the rice cooking process.

(10) Inner Lid The inner lid 146 is a member that is placed above the inner pot when the lid body 140 is in the closed state, covers and seals the opening of the inner pot, and forms a housing together with the inner pot, and is detachably attached to the underside of the lid reinforcement part 141. As shown in Figures 4, 5, and 8 to 12, the inner lid 146 is mainly composed of a main body part CB, annular packing CP, an inner lid cover CV, an abnormal pressure relief valve SV, and packing PK. These components will be described in detail below.

(10-1) Main Body The main body CB is a metal member, and is formed of a base plate CB1, a side wall CB2, and a flange CB3, as shown in Figs. 4, 5, 8 to 12. The base plate CB1 is substantially disk-shaped, as shown in Figs. 4, 5, and 8. The base plate CB1 is formed with a valve port OS, a pressure adjustment port, and an opening (see Figs. 4, 9 to 12). As shown in Figs. 4, 5, and 8, when the inner lid cover CV is attached to the upper side of the base plate CB1, the pressure adjustment port and the pressure adjustment port of the inner lid cover CV communicate with each other to form a pressure adjustment port VO, and the opening and the opening of the inner lid cover CV communicate with each other to form an opening OT. The valve port OS serves to communicate the internal space of the casing formed by the inner pot and the inner lid 146 with the external space. As shown in Figures 9 and 10, the valve opening OS is normally closed by the closing part SQ of the valve body SM of the pressure abnormality release valve SV (i.e., when the internal pressure of the inner pot has not reached the threshold value and the pressure abnormality release valve SV is not operating). The pressure adjustment opening VO is closed by the pressure adjustment device 144 during pressure cooking operation, as described above. The opening OT functions as a passage for steam and sticky rice, and is closed by the closing part PK1 of the packing PK during pressure cooking operation. The side wall part CB2 extends upward from the outer end of the base part CB1, as shown in Figures 5, 9 to 12. The flange part CB3 extends outward from the upper end of the side wall part CB2, as shown in Figures 5, 9 to 12.

(10-2) Annular Gasket The annular gasket CP is disposed around the side wall CB2 of the main body CB and is attached to the underside of the flange CB3 of the main body CB as shown in Figures 3, 9 to 12. The annular gasket CP serves to seal the internal space of the inner pot when the lid 140 is in the closed state.

(10-3) Inner Lid Cover The inner lid cover CV is a member attached to the upper surface of the substrate portion CB1 of the main body portion CB. When the inner lid cover CV is attached to the upper surface of the substrate portion CB1 of the main body portion CB, as shown in Figs. 9 to 12, an accommodation space AS is formed between the inner lid cover CV and the main body portion CB. Here, the total height of the accommodation space AS is equal to or less than the total height of the conical spring SP (described later) in its natural state. Also, as shown in Figs. 5 to 12, the inner lid cover CV is formed of the substrate portion CV1, the side wall portion CV2, and the top wall portion CV3. As shown in Figs. 5 and 8, the substrate portion CV1 has an approximately disk shape. As described above, the substrate portion CV1 is formed with a pressure adjustment port for forming a pressure adjustment port VO together with the substrate portion CB1 of the main body portion CB, and an opening for forming an opening OT together with the substrate portion CB1 of the main body portion CB. As shown in Figs. 6 to 8, 10 and 12, a notch CV1a is formed in the front and rear of the boundary between the substrate CV1 and the side wall CV2. This notch CV1a is for connecting the accommodation space AS to the outside. The side wall CV2 is formed in the substrate CV1 around the valve port OS of the main body CB in a planar perspective view (see Figs. 9 to 12). As shown in Figs. 5 to 7 and 9 to 12, the side wall CV2 has a generally truncated cone shape. As shown in Figs. 5 to 7 and 9 to 12, the top wall CV3 extends inward from the upper end of the side wall CV2. As shown in Figs. 6, 7, 9 to 12, an insertion port CV3a is formed in the top wall CV3. As shown in Figures 7, 11 and 12, when the internal pressure of the inner pot exceeds the threshold value and the pressure abnormality relief valve SV is activated, the upper end portion of the inner wall portion SO4 of the base portion SO of the valve body SM of the pressure abnormality relief valve SV and the top wall portion SO5 protrude from this insertion hole CV3a. As shown in Figures 9 to 12, the top wall portion CV3 also serves to support the conical spring SP of the pressure abnormality relief valve SV. As shown in Figures 9 and 10, the top wall portion CV3 is located lower than the flange portion CB3 of the main body portion CB.

(10-4) Abnormal Pressure Relief Valve The abnormal pressure relief valve SV is a safety valve for releasing the force applied to the lid body 140 via the inner lid 146 when the internal pressure of the inner pot reaches or exceeds a threshold value (for example, 1.35 atmospheres or more), and as shown in Figures 9 to 12, is mainly composed of a valve body SM, a conical spring SP, etc. These components will be described in detail below.

(10-4-1) Valve body As shown in Figures 9 and 10, when the internal pressure of the inner pot does not reach the threshold, the valve body SM is biased toward the valve opening OS of the base plate portion CB1 of the main body portion CB by the conical spring SP. Also, as shown in Figures 9 and 10, when the internal pressure of the inner pot does not reach the threshold, the valve body SM is contained in the accommodation space AS (Note that, as mentioned above, when the internal pressure of the inner pot reaches or exceeds the threshold, a part of it protrudes from the insertion opening CV3a of the top wall portion CV3 of the inner lid cover CV). Also, as shown in Figures 9 to 14, the valve body SM is mainly composed of a base portion SO and a closing portion SQ, etc.

As shown in Figs. 11 to 14, the base portion SO is formed of a bottom wall portion SO1, an outer wall portion SO2, a wing portion SO3, an inner wall portion SO4, a top wall portion SO5, and a rib SO6. As shown in Figs. 13 and 14, the bottom wall portion SO1 has a substantially circular ring shape (i.e., a substantially disk shape with an opening in the center). As shown in Figs. 11 to 14, the outer wall portion SO2 has a substantially cylindrical shape and extends upward from the outer end of the bottom wall portion SO1. As shown in Figs. 12 to 14, the wing portion SO3 extends outward from the front and rear ends of the outer wall portion SO2. As shown in Figs. 11 to 13, the inner wall portion SO4 has a substantially cylindrical shape and extends upward from the inner end of the bottom wall portion SO1. As shown in Figs. 11, 12, and 14, a blocking portion SQ is fitted inside the inner wall portion SO4. As shown in Figures 11 to 13, the top wall portion SO5 is generally disk-shaped and extends inward from the upper end of the inner wall portion SO4. As shown in Figures 6, 9, and 10, the top wall portion SO5 forms a flat surface together with the top wall portion CV3 of the inner lid cover CV when the internal pressure of the inner pot does not reach the threshold value. The top wall portion SO5 is located lower than the flange portion CB3 of the main body portion CB regardless of the internal pressure of the inner pot (see Figures 9 to 12). The rib SO6 extends inward from the inner peripheral surface of the inner wall portion SO4 as shown in Figures 11 and 12. This rib SO6 is for determining the height position of the closing portion SQ, and is located above the closing portion SQ when the closing portion SQ is fitted inside the inner wall portion SO4. As shown in Figures 11 to 14, six notches SOa are formed in the base portion SO, extending from the inner end of the bottom wall portion SO1 to the lower end of the inner wall portion SO4. As shown in Figure 7, when the internal pressure of the inner pot exceeds a threshold value and the valve body SM moves upward due to a force in the opposite direction to the biasing force of the conical spring SP, the notches SOa are exposed. Then, steam from within the inner pot passes through the valve port OS of the base portion CB1 of the main body portion CB and then through the notches SOa, and is released to the outside of the inner pot, releasing the internal pressure of the inner pot.

The blocking portion SQ is for blocking the valve opening OS of the base portion CB1 of the main body portion CB when the internal pressure of the inner pot has not reached the threshold value, and is formed from an elastic material (e.g., rubber, elastomer, etc.). The blocking portion SQ has a roughly cylindrical shape (see Figures 9 to 12), and as described above, is fitted inside the inner wall portion SO4 of the base portion SO below the rib SO6 of the base portion SO.

(10-4-2) Conical spring As described above, the conical spring SP biases the valve body SM toward the valve opening OS of the base plate part CB1 of the main body part CB when the internal pressure of the inner pot has not reached the threshold value. When the internal pressure of the inner pot reaches the threshold value, the conical spring SP moves the valve body SM upward with a force in the opposite direction to the biasing direction, opening the valve opening OS of the base plate part CB1 of the main body part CB. Furthermore, as shown in Figures 9 to 12, the conical spring SP is completely contained in the accommodation space AS regardless of the internal pressure of the inner pot. At this time, the conical spring SP is in a natural state or a compressed state, and as shown in Figures 9 to 12, the part of the conical spring SP with a larger coil diameter is located on the upper side, and the part of the conical spring SP with a smaller coil diameter is located on the lower side. The natural state of the conical spring SP refers to a state in which no force is applied to the conical spring SP and the conical spring SP is not stretched or contracted. In the rice cooker 100 according to the embodiment of the present invention, in the natural state, the conical spring SP has a total height in the biasing direction (i.e., the vertical direction) that is smaller than the total width in the direction perpendicular to the biasing direction. Here, it is preferable that the total height/total width of the conical spring SP is 1/3 or less in the natural state. The total height of the conical spring SP decreases as the conical spring SP is compressed, and becomes the same as the diameter (thickness) of the wire that forms the conical spring SP when the conical spring SP is fully compressed. In other words, when the conical spring SP is fully compressed, the wire forms a spiral shape on a plane.

(10-5) Gasket As shown in Figs. 4, 5 and 8, the gasket PK is a member for closing the opening OT during pressure cooking operation to increase the internal pressure of the inner pot, and is made of an elastic material (e.g., rubber, elastomer, etc.). As shown in Figs. 4, 5 and 8, the gasket PK is made of a closing part PK1, an insert part PK2 and a drop prevention part PK3. As shown in Fig. 4, the closing part PK1 has a rounded rectangular shape in bottom view. In addition, when the drop prevention part PK3 is placed on the top surface of the base part CB1 of the main body part CB (see Fig. 5), the top surface of the closing part PK1 and the bottom surface of the base part CB1 of the main body part CB are slightly separated. However, when the packing PK is lifted by steam generated in the inner pot during pressure cooking, the upper surface of the closing part PK1 comes into close contact with the bottom surface of the base part CB1 of the main body part CB, closing the opening OT of the inner lid 146. The insertion part PK2 extends upward from both ends of the closing part PK1 and has a substantially cylindrical shape. The insertion part PK2 is inserted into the insertion openings formed on both sides of the opening OT so as to move from the bottom to the top. The drop-out prevention part PK3 is formed in the center of the height direction of the insertion part PK2 and has a substantially truncated cone shape (see FIG. 5). When the insertion part PK2 is inserted into the insertion opening, the drop-out prevention part PK3 is also inserted into the insertion opening. Then, as shown in FIG. 5, the drop-out prevention part PK3 is placed on the upper surface of the base part CB1 of the main body part CB after passing through the insertion opening. Although the diameter of the bottom of the fall-prevention portion PK3 is larger than the diameter of the insertion opening, since the packing PK is made of an elastic material, the fall-prevention portion PK3 can expand and contract to pass through the insertion opening.

5. Hinge Part As described above, the hinge part 150 attaches the cover 140 to the main body 110 so that the cover 140 is rotatable relative to the main body 110. The hinge part 150 biases the cover 140 in the opening direction by a torsion spring (not shown).

<Features of the rice cooker according to the embodiment of the present invention>
(1)
In the rice cooker 100 according to the embodiment of the present invention, the pressure abnormality release valve SV of the inner lid 146 has a conical spring SP as a biasing member that biases the valve body SM toward the valve opening OS formed in the main body CB of the inner lid 146. In this rice cooker 100, the conical spring SP of the pressure abnormality release valve SV of the inner lid 146 has a total height in the biasing direction that is smaller than the total width in the direction perpendicular to the biasing direction in the natural state. In addition, when the conical spring SP of the pressure abnormality release valve SV of the inner lid 146 is fully compressed, the diameter and total height of the wire forming the conical spring SP are the same. On the other hand, in a cylindrical spiral coil spring, even when fully compressed, the wires come into contact with each other and are stacked, so that the height is above a certain level even in the compressed state. Therefore, unlike a cylindrical spiral coil spring, the conical spring SP can keep its total height as low as possible. Therefore, in this rice cooker 100, compared to when a single biasing member such as a cylindrical spiral coil spring is used for the abnormal pressure relief valve SV of the inner lid 146, it is possible to minimize the bulge of the convex portion that occurs when the inner pot and inner lid 146 are provided in the housing. Therefore, in this rice cooker 100, compared to when a single biasing member such as a cylindrical spiral coil spring is used for the abnormal pressure relief valve SV of the inner lid 146, it is possible to maximize the ease of maintenance in the vicinity of the convex portion.

(2)
In the rice cooker 100 according to the embodiment of the present invention, the conical spring SP of the pressure abnormality release valve SV of the inner lid 146 is accommodated in the accommodation space AS formed between the inner lid cover CV and the main body CB of the inner lid 146. The total height of the accommodation space AS is equal to or less than the total height of the conical spring SP of the pressure abnormality release valve SV of the inner lid 146 in its natural state. Therefore, in this rice cooker 100, the conical spring SP of the pressure abnormality release valve SV of the inner lid 146 can always be in its natural state or compressed state. Therefore, in this rice cooker 100, the conical spring SP of the pressure abnormality release valve SV is compressed to a degree that is not completely compressed (in other words, after leaving room for the conical spring SP to be further compressed when the internal pressure of the inner pot becomes equal to or greater than the threshold value), and the closing portion SQ of the valve body SM of the pressure abnormality release valve SV closes the valve opening OS of the main body CB, thereby making it possible to further reduce the bulge of the convex portion.

(3)
In the rice cooker 100 according to the embodiment of the present invention, a notch CV1a that connects the storage space AS to the outside is formed in the inner lid cover CV of the inner lid 146. Therefore, in this rice cooker 100, it is possible to prevent liquids such as water or viscous liquids such as sticky paste from remaining in the storage space AS as much as possible.

<Modification>
(A)
In the rice cooker 100 according to the previous embodiment, the pressure abnormality release valve SV of the inner lid 146 has a conical spring SP as a biasing member for biasing the valve body SM toward the valve opening OS formed in the body part CB of the inner lid 146. However, the pressure abnormality release valve SV of the inner lid 146 may have a biasing member other than the conical spring SP (e.g., a leaf spring, a cylindrical spiral coil spring arranged in multiple places, a magnet, etc.) instead of the conical spring SP. When multiple cylindrical spiral coil springs are arranged, for example, multiple cylindrical spiral coil springs may be arranged circumferentially along the bottom surface of the top wall part CV3 of the inner lid cover CV of the inner lid 146, or another cylindrical spiral coil spring may be arranged concentrically with the cylindrical spiral coil spring. When the biasing member is a magnet, because the main body CB of the inner lid 146 is made of metal, the magnet biases the valve main body SM when attempting to attach to the main body CB of the inner lid 146. Similar to the conical spring SP, biasing members other than the conical spring SP also need to have a total height in the biasing direction smaller than a total width in a direction perpendicular to the biasing direction in the natural state.

(B)
In the rice cooker 100 according to the previous embodiment, the conical spring SP of the abnormal pressure release valve SV of the inner lid 146 was accommodated in the accommodation space AS formed between the inner lid cover CV and the main body CB of the inner lid 146. However, as long as the height position of the part of the conical spring SP of the abnormal pressure release valve SV of the inner lid 146 with a large coil diameter can be fixed, the conical spring SP of the abnormal pressure release valve SV of the inner lid 146 does not need to be accommodated in the accommodation space AS, and the accommodation space AS does not need to be formed.

(C)
In the rice cooker 100 according to the above embodiment, the cutout CV1a that connects the storage space AS to the outside is formed in the inner lid cover CV of the inner lid 146. However, the cutout CV1a does not have to be formed in the inner lid cover CV of the inner lid 146, and the storage space AS may be connected to the outside by a configuration other than the cutout CV1a.

(D)
In the rice cooker 100 according to the previous embodiment, the inner lid cover CV of the inner lid 146 is attached to the upper surface of the base portion CB1 of the body portion CB of the inner lid 146. However, the inner lid cover CV and the body portion CB of the inner lid 146 may be integrally molded.

(E)
In the rice cooker 100 according to the previous embodiment, two notches CV1a were formed in the boundary between the base plate CV1 of the inner lid cover CV of the inner lid 146 and the side wall CV2. However, the number of notches CV1a is not limited to two, and only one notch CV1a may be formed, or three or more notches CV1a may be formed. Also, a notch that communicates the storage space AS with the outside may be formed in the side wall CV2 or top wall CV3 of the inner lid cover CV of the inner lid 146, or the base plate CB1 of the main body CB of the inner lid 146.

(F)
In the rice cooker 100 according to the previous embodiment, six notches SOa were formed in the base portion SO of the valve body SM of the abnormal pressure relief valve SV of the inner lid 146. However, the number of notches SOa is not limited to six, and one to five notches SOa may be formed, or seven or more notches SOa may be formed.

(G)
In the above embodiment, the present invention is applied to the rice cooker 100, but the present invention may be applied to other pressure cookers or appliances.

The above modifications may be used alone or in combination.

100 Rice cooker (cooking appliance)
111 Housing (container)
140 Lid 146 Inner lid (lid)
AS Accommodating space CB1 Substrate portion (wall portion in which a communication hole is formed)
CV Inner lid cover (biasing member support part)
CV1a Notch OS Valve port (communicating hole)
SM Valve body (valve element)
SP Conical spring (biasing member)
SV Pressure Abnormality Release Valve (Safety Valve Structure)

Claims (5)

A safety valve structure provided in a housing so as to be capable of closing a communication hole that communicates an internal space and an external space of the housing,
A valve body,
a biasing member that, when an internal pressure of the housing becomes equal to or greater than a first threshold value, moves the valve body by a force opposite to a force biasing the valve body toward the communication hole, thereby opening the communication hole and connecting the internal space and the external space,
A safety valve structure in which, in a natural state of the biasing member, an overall height of the biasing member in a biasing direction is smaller than an overall width of the biasing member in a direction perpendicular to the biasing direction. 2. The safety valve structure according to claim 1, wherein the biasing member is a conical spring. the housing has a biasing member support portion that supports the biasing member,
3. The safety valve structure according to claim 1, wherein the biasing member is accommodated between a wall portion of the housing in which the communication hole is formed and the biasing member support portion. the housing further has an accommodation space defined by the biasing member support portion and the wall portion,
4. The safety valve structure according to claim 3, wherein the biasing member support portion or the wall portion is formed with a notch for connecting the accommodation space to the outside. A container opening upward;
a lid disposed above the container to cover an opening of the container;
a communication hole formed in the lid that communicates a space surrounded by the container and the lid with the outside;
a safety valve structure including a valve body that is provided on the cover body so as to be able to close the communication hole, and a biasing member that, when the internal pressure of the space becomes equal to or higher than a first threshold value, moves the valve body by a force opposite to a force that biases the valve body toward the communication hole, thereby opening the communication hole and connecting the space to the outside,
A cooking appliance in which, in a natural state of the urging member, an overall height of the urging member in a urging direction is smaller than an overall width of the urging member in a direction perpendicular to the urging direction.

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