JP2007236405A - Safety valve structure in pressure type rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a pressure regulating means function always normally in a pressure type rice cooker to boil rice in the state of pressure higher than normal by having the pressure regulating means. <P>SOLUTION: The pressure type rice cooker capable of cooking under the high-pressure state has an atmospheric air releasing safety valve, separate from the pressure regulating means, for discharging steam from a through hole 5 bored in an inner lid 4 to a steam passage 6 penetrating the space between the bottom of a lid body 3 and the inner lid 4. The elastic packing 9 is fixed to the bottom of the lid body 3 to be used as the atmospheric air releasing safety valve to elastically close the through hole 5 communicating with the steam passage 6. The rice cooker also has a spacer member 9 to prevent the space between the bottom of the lid body 3 and the inner lid 4 from becoming narrower than a prescribed space so that the rise of the limit sealing pressure of the elastic packing, caused by the bending of the inner lid 4 and strong compression of the elastic packing when the pressure inside a pot 2 is increased, can be avoided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  This invention is invention regarding the safety structure of the pressure type rice cooker which can cook rice cooking in a state higher pressure than usual by providing a pressure adjustment means.

  The general structure of a rice cooker is that the pot is housed inside a rice cooker body equipped with heating means, and the upper end opening of the pot is closed by an inner lid attached to a lid that is pivotally supported on the back of the rice cooker body. Cooking.

An electric rice cooker is known as a pressure rice cooker that can cook rice in a high pressure state of, for example, about 1.1 to 1.3 atm by providing a pressure adjusting means. In the pressure rice cooker, if the pressure adjustment means does not function normally for some reason, it exceeds the seal limit pressure of the lid packing that closes the top opening of the pot, and the temperature is high between the rice cooker body and the lid. There is a risk that high-pressure steam will be ejected.
In order to avoid the risk of jetting out high-temperature and high-pressure steam as described above, as disclosed in Patent Document 1, the applicant passes through the space between the bottom surface of the lid body and the inner lid from the opening of the inner lid. The idea of providing an open-air safety valve for discharging steam in the steam passage is devised.
JP 2003-339524 A

  The pressure-type rice cooker disclosed in Patent Document 1 houses a kettle inside a rice cooker body provided with heating means, and an inner lid attached to the bottom surface of a lid that is pivotally supported by the back of the rice cooker body. The lid is provided with pressure adjusting means that communicates with the through hole of the inner lid and discharges the steam to a steam passage that passes through the space between the bottom of the lid and the inner lid. .

As an air release safety valve, a cylindrical elastic packing is fixed to the bottom of the lid, and the opening end of the elastic packing is pressed on the upper surface of the inner lid so as to surround the outer periphery of the through hole. When the internal pressure becomes abnormally high and exceeds the seal limit pressure, the steam is released from the contact surface between the elastic packing and the inner lid to the steam passage. However, when the internal pressure increases as shown in FIG. 9, the inner lid may bend from the normal state shown in (a) as shown in (b), and a phenomenon may occur in which the distance between the lid and the inner lid is reduced. It turned out to be. As described above, when the inner lid is bent and the distance between the lid and the inner lid is reduced, the elastic packing is strongly compressed, and the pressure resistance as an atmosphere release safety valve, that is, the sealing limit pressure of the elastic packing is increased. It may not work properly even under high pressure.
The present invention realizes a safety valve structure in which an atmosphere release safety valve constituted by elastic packing always functions normally and safety can be ensured so as not to cause an abnormal situation where the atmosphere release safety valve does not operate as described above. It is the purpose.

  The present invention accommodates a pot 2 inside a rice cooker body 1 provided with heating means, and opens an upper end of the pot 2 by an inner lid 4 attached to the bottom surface of a lid 3 pivotally supported by the back of the rice cooker body 1. A pressure adjusting means 7 is provided for sealing the portion 2a and communicating with the through hole of the inner lid 4 in the lid 3 and discharging steam to the steam passage 6 passing through the space between the bottom surface of the lid 3 and the inner lid 4. It is related with the pressure type rice cooker which can cook in a high pressure state by providing.

According to the first aspect of the present invention, the cylindrical elastic packing 8 whose upper end is closed is provided on the bottom surface of the lid 3, and the front end opening of the elastic packing 8 is formed on the inner lid 4 on the upper surface of the inner lid 4. The through-hole 5 communicating with the steam passage 6 is pressed so as to surround it. As a result, the through hole 5 is sealed, and when the internal pressure of the hook 2 rises above the sealing limit pressure of the elastic packing 8, high-pressure steam is generated from between the opening 8a of the elastic packing 8 and the inner lid 4. To the steam passage 6.
Furthermore, a spacer member 9 is disposed between the bottom surface of the lid 3 and the inner lid 4 to prevent the gap between the bottom surface of the lid 3 and the inner lid 4 from becoming narrower than a certain distance.

  According to the second aspect of the present invention, as a specific structure of the spacer member 9, the spacer member 9 has a cylindrical shape surrounding the elastic packing 8, fixed to the upper surface of the inner lid 4 or the bottom surface of the lid body 3, The through hole 10 through which the steam passes or the cutout portion 9b of the peripheral wall 9a is formed.

  The invention according to claim 3 relates to another specific structure of the spacer member 9. That is, the spacer member 9 has a peripheral wall 9a formed on a flat plate portion 9c serving as a valve seat having a through hole 5 at the center. The flat plate portion 9c of the spacer member 9 is formed on the inner lid 4. The through hole 5 that functions as a part and is formed in the flat plate portion 9 c communicates with the steam passage 6.

  The invention described in claim 4 relates to a specific structure of another spacer member 9. That is, a heating plate 12 serving as a bottom surface of the lid body 3 is disposed below the bottom plate 11 that is a structural member of the lid body 3, a protruding portion 13 is formed downward from the bottom plate 11, and a tip portion of the protruding portion 13 Is a spacer member 9 that reaches the inner lid 4 through the heating plate 12.

  According to the safety valve structure in the pressure rice cooker of the present invention as set forth in claim 1, the air release safety valve by the elastic packing 8 that discharges steam to the steam passage 6 that passes through the space between the bottom surface of the lid 3 and the inner lid 4. In the pressure-type rice cooker provided with, the inner lid 4 is prevented from being bent by the internal pressure, the seal limit pressure by the elastic packing 8 is constant, and the safety valve structure can always function normally. And according to invention of Claim 2, the structure which makes the safety valve structure of Claim 1 function stably is realizable.

According to the third aspect of the invention, the spacer member 9 can be mounted on the inner lid 4, and the through hole 5 is formed in the flat plate portion 9 c of the spacer member 9 manufactured as a separate member from the inner lid 4. Therefore, the surface of the flat plate portion 9c can be finished in a smooth state preferable as a valve seat.
Further, according to the invention described in claim 4, the structure of the spacer member can be simplified, and the present invention can be carried out without increasing the number of parts.

Hereinafter, an embodiment of a safety valve structure in a pressure rice cooker according to the present invention will be described with reference to the accompanying drawings.
1 is a partial cross-sectional view showing a part of a pressure rice cooker having a safety valve structure according to the present invention, and FIG. 2 is a perspective view showing an example of a spacer member of the embodiment in FIG. 3 is a perspective view showing another example of the spacer member of the embodiment shown in FIG. 1, and FIG. 4 is an enlarged view showing a part of a pressure rice cooker having a safety valve structure showing another embodiment. FIG. 5 is a partial cross-sectional view, FIG. 5 is a partial cross-sectional view showing a part of a pressure rice cooker having a safety valve structure showing still another embodiment, and FIG. 6 is a safety valve structure showing still another embodiment. FIG. 7 is a cross-sectional view showing an operation state of the elastic packing, and FIG. 8 is an enlarged cross-sectional view of a portion that leads to the outside of the steam passage. FIG. 9 is a partial cross-sectional view showing a part of a conventional pressure rice cooker.

  As shown in FIG. 1, the pressure rice cooker according to the present invention forms a pot accommodating portion 14 opened upward in the rice cooker main body 1 and is heated by heating means such as an electromagnetic induction coil therein. 2 is accommodated. The upper end opening 2a of the pot 2 accommodated inside the rice cooker body 1 is pivotally supported by the shaft 15 at the back of the rice cooker body 1 and the front end is locked to the rice cooker body 1 by the lid hook 16. 3 is specifically closed by the inner lid 4 attached to the bottom surface of the lid 3. That is, the sealed state is realized by bringing the inner lid packing 17 mounted on the outer periphery of the inner lid 4 functioning as a heat sink close to the upper end opening 2a of the shuttle 2.

  A heating plate 12 heated by a lid heater 18 is disposed on the bottom surface of the lid 3, and the heating plate 12 is heated by bringing a part of the inner lid 4 into contact with the heating plate 12 (for example, an annular ridge). Is transmitted to the inner lid 4 functioning as a heat radiating plate, preventing temperature adjustment in the hook 2 and condensation during heat insulation. On the other hand, a seal packing 19 attached to the outer periphery of the heating plate 12 is brought into close contact with the upper surface of the inner lid 4 to form a space that is blocked from the outside between the heating plate 12 and the inner lid 4. It functions as the passage 6. That is, as shown in FIG. 8, a ventilation hole 20 is formed in a part of the heating plate 12, and the ventilation hole 20 passes through, for example, the separation structure portion 21 and opens to the upper surface of the lid 3. Communicate to 22.

  A pressure adjusting means 7 is disposed on the lid 3 (a sensor portion constituting a part of the pressure adjusting means is shown in FIG. 1). By providing the pressure adjusting means, when the pressure in the pot 2 exceeds a certain pressure, the steam in the pot 2 is allowed to escape to the steam passage 6 to cook rice under high pressure, for example, 1.1 to 1.3 atm. it can. Apart from the pressure adjusting means 7, the lid 3 is provided with an air release safety valve structure A that opens the vapor to the atmosphere when the pressure adjusting means does not function normally.

  In order to control opening and closing of a valve (not shown) of the pressure adjusting means 7, the pressure in the shuttle 2 is detected. In order to detect the pressure in the hook 2, a space opened in the hook 2 and isolated from the outside of the vessel is realized, and the pressure in this space is detected. That is, as shown in FIGS. 5 and 6, the through hole 5 is formed in the inner lid 4 or the flat plate portion 9c of the spacer member 9 which is attached to the inner lid 4 and constitutes a part of the inner lid as shown in FIGS. And a cylindrical elastic packing 8 is attached to the bottom surface of the lid 3. Then, the tip of the elastic packing 8 is sealed by being brought into close contact with the outer upper surface of the through hole 5 of the inner lid 4, and the sensor 23 is mounted in an airtight state on the upper end opening of the cylindrical elastic packing 8.

The elastic packing 8 functions as an air release safety valve. That is, as shown in FIG. 7A, the elastic packing 8 has a cylindrical shape that is airtightly attached to the mounting hole of the heating plate 12 that is the bottom surface of the lid 3, and is downward from the heating plate 12. The shape of the protruding tip part is formed so that the maximum position is located above the opening end 8a so that the maximum diameter is formed, and the inclined wall 8b from the maximum diameter part toward the opening end 8a and the inclined wall 8c directed upward are provided. By providing the bellows shape and elastically pressing the open end 8a against the inner lid 4, an airtight state is realized as shown in FIG.
In the airtight state shown in FIG. 7 (b), when the internal pressure rises above the durable pressure, the inclined wall 8b opens outward as shown in FIG. 7 (c), and the steam passes through the steam passage as shown by arrows. 6 is discharged.

  At this time, in the conventional pressure rice cooker shown in FIG. 9, as shown in FIG. 9 (b), the inner lid 4 is bent by the internal pressure of the hook. That is, the distance X between the heating plate 12 which is the bottom surface of the lid 3 shown in FIG. 7B and the inner lid 4 is narrowed to the distance X ′ as shown in FIG. When the interval X ′ is narrowed, the elastic packing 8 is strongly compressed as shown in FIG. 7D, and the seal limit pressure as the packing is increased. For this reason, it withstands a high pressure state higher than a predetermined pressure, and the function as a safety valve becomes unstable. Focusing on this point, the present invention arranges the spacer member 9 between the bottom surface of the lid body 3 and the inner lid 4, so that the bottom surface and the inner lid of the lid body 3 as shown in FIG. The interval of 4 should not be narrowed as shown in FIG.

  In the embodiment shown in FIG. 1, a spacer member 9 is attached to the inner lid 4. As shown in FIG. 2, the spacer member 9 attached to the inner lid 4 forms a peripheral wall 9a as a rising portion on a flat plate portion 9c serving as a valve seat having a through hole 5 at the center, and passes steam through the peripheral wall 9a. A through-hole 10 is formed, or a peripheral wall cutout 9b is provided. The steam ejected from the outer periphery of the elastic packing 8 functioning as a safety valve passes through the through hole 10 and is discharged to the steam passage 6. The tip of the peripheral wall 9a is in contact with the lower surface of the heating plate 12 serving as the bottom surface of the lid 3, so that the distance between the heating plate 12 and the inner lid 4 is not closer than the height of the peripheral wall 9a. That is, the peripheral wall 9a functions as a spacer.

  The spacer member 9 shown in FIG. 2 has a fitting groove 9 d formed on the outer periphery of the lower end of the peripheral wall 9 a, the peripheral wall 9 a is inserted into the relatively large mounting hole 24 of the inner lid 4 from below, and the inner lid 4 is fixed by the fixing ring 25. To fix. The spacer member 9 is airtightly attached to the relatively large mounting hole 24 of the inner lid 4, and the flat plate portion 9 c functions as a part of the inner lid 4. The spacer member 9 is preferably molded integrally with, for example, a synthetic resin material, and the surface of the flat plate portion 9c is preferably finished to a smooth surface suitable for the elastic packing 8 to be in close contact.

  The spacer member shown in FIG. 2 has a through hole 10 serving as a vent hole in a part of the peripheral wall 9a, but the embodiment shown in FIG. 3 omits a part of the peripheral wall and cuts out portions 9b and 9b. The notch 9b functions as a passage for the steam ejected from the outer periphery of the elastic packing 8, and the steam is discharged to the steam passage 6. That is, the peripheral wall 9a has a structure equivalent to that a plurality of legs functioning as spacers are arranged on a circular locus centering on the through hole 5 by forming a notch portion 9b. The number and width of the notch portions 9b are not particularly limited, but are preferably equally spaced as much as possible.

  The spacer member 9 of the embodiment shown in FIG. 4 has an outer flange 9e formed on the outer peripheral surface of the peripheral wall 9a raised from the flat plate portion 9c, and is pinned or screwed to the inner lid 4 using the outer flange 9e. Is. In addition to providing a through hole in the peripheral wall 9a, forming a cutout portion of the peripheral wall 9a to secure a steam passage, and letting the steam ejected from the elastic packing to escape to the safety steam passage 6 is shown in FIGS. It is the same as the case of form.

  The spacer member 9 according to the embodiment shown in FIG. 5 fixes the spacer member 9 having a certain height to the bottom surface of the heating plate 12 that forms the bottom surface of the lid 3 by using pins 27. The spacer member 9 fixed to the bottom surface of the heating plate 12 may be, for example, a short cylinder having an outer casing 9f, and a through hole serving as a steam passage may be formed in a short cylindrical peripheral wall. The separated spacer member 9 may be fixed to the heating plate 12. The distance between the heating plate 12 and the inner lid 4 is prevented from being narrowed by the tip of the spacer member 9 fixed to the heating plate 12 coming into contact with the upper surface of the inner lid 4.

In the embodiment shown in FIG. 6, a projecting portion 13 is formed downward on a bottom plate 11 that is a structural member of the lid 3, and the tip portion of the projecting portion 13 penetrates the heating plate 12 so that the tip is the inner lid 4. The spacer member 9 reaches the upper surface of the spacer. The protruding portion 13 formed on the bottom plate 11 has, for example, a plurality of rods that hang down on a circular locus centering on the center of the elastic packing 8, and the penetration portion of the heating plate 12 is made airtight by attaching the packing 28. Hold so that steam does not flow above the heating plate.
Alternatively, the protruding portion 13 formed on the bottom plate 13 may be formed in a cylindrical shape, the tip portion may be formed in a comb shape, and the comb portion may penetrate the heating plate 12.

  The present invention can be carried out by arranging a spacer member of an arbitrary form between the heating plate 12 and the inner lid 4, but the spacer member 9 is arranged in a manner surrounding the center of the elastic packing 8. It is desirable to do. In the illustrated embodiment, the bellows-like elastic packing 8 is used, but the elastic packing 8 may be other than the bellows. The reason is that when at least a cylindrical packing formed of an elastic body is pressed and sealed, the seal limit pressure changes depending on the pressing force. This is because by keeping the distance between the bottom surface of the lid 3 and the inner lid 4 constant, the pressing force of the elastic packing existing therebetween can be kept constant.

  Among the illustrated embodiments described above, in the embodiment of FIGS. 1 and 4, the spacer member 9 having the flat plate portion 9 c is used and the through hole 5 is formed in the flat plate portion 9 c of the spacer member 9. . In other words, the flat plate portion 9c of the spacer member 9 functions as a part of the inner lid. On the other hand, in the embodiment shown in FIGS. 5 and 6, the through hole 5 formed in the inner lid 4 is closed by the elastic packing 8. The point is to ensure safety by preventing the sealing limit pressure of the elastic packing that closes the through hole communicating with the inside of the hook 2 and the steam passage 6 from becoming larger than the safe pressure.

FIG. 1 is a partial cross-sectional view showing a part of a pressure rice cooker provided with a safety valve structure according to the present invention, FIG. 2 is a perspective view showing an example of the spacer member of the embodiment in FIG. FIG. 3 is a perspective view showing another example of the spacer member of the embodiment shown in FIG. FIG. 4 is an enlarged partial cross-sectional view of a part of a pressure rice cooker having a safety valve structure showing another embodiment; FIG. 5 is an enlarged partial cross-sectional view of a part of a pressure rice cooker having a safety valve structure showing still another embodiment, FIG. 6 is an enlarged partial cross-sectional view of a part of a pressure rice cooker having a safety valve structure showing still another embodiment; FIG. 7 is a sectional view showing an operating state of the elastic packing, FIG. 8 is an enlarged cross-sectional view of a portion of the steam passage that leads to the outside of the container, FIG. 9: is a fragmentary sectional view which expands and shows a part of conventional pressure type rice cooker.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rice cooker main body, 2 ... Pot, 2a ... Upper end opening part, 3 ... Cover body, 4 ... Inner lid, 5 ... Through-hole, 6 ... Steam passage, 7 ... Pressure adjusting means, 8 ... Elastic body packing, 8a ... Tip opening, 9 ... Spacer member, 9a ... Peripheral wall, 9b ... Notch, 9c ... Flat plate part, 9d ... Fitting groove, 9e ... Outer gutter, 9f ... Outer gutter, 10 ... Through hole, 11 ... Bottom plate, 12 ... Heating plate, 13 ... Projection, 14 ... Pot housing, 15 ... Shaft, 16 ... Lid hook, 17 ... Inner lid packing, 18 ... Lid heater, 19 ... Seal packing, 20 ... Vent, 21 ... 22 ... Exhaust hole, 23 ... Sensor, 24 ... Mounting hole, 25 ... Fixing ring, 26,27 ... Pin, 28 ... Packing, A ... Air release safety valve structure.

Claims (4)

The pot is housed inside the rice cooker body equipped with heating means, and the upper end opening of the pot is sealed by an inner lid attached to the bottom surface of the lid pivotally supported by the back of the rice cooker body. Is a pressure-type rice cooker that can be cooked in a high-pressure state by providing pressure adjusting means that discharges steam into a steam passage that communicates with the through hole of the inner lid and passes through the space between the bottom surface of the lid and the inner lid. In the vessel
A cylindrical elastic packing whose upper end is closed is provided on the bottom surface of the lid, and the tip opening of the elastic packing is pressed so as to surround a through-hole communicating with a steam passage formed in the inner lid on the upper surface of the inner lid. By sealing the through-hole, when the internal pressure of the hook rises above the sealing limit pressure of the elastic packing, high-pressure steam is released from the gap between the elastic packing tip opening and the inner lid to the steam passage,
A safety valve structure in a pressure rice cooker, wherein a spacer member is disposed between the bottom surface of the lid and the inner lid to prevent the distance between the bottom surface of the lid and the inner lid from becoming narrower than a certain distance.   The spacer member has a cylindrical shape surrounding the elastic packing, and is fixed to the upper surface of the inner lid or the bottom surface of the lid, and a through hole or a notch portion of the peripheral wall is formed in a part of the peripheral wall to allow vapor to pass through. The safety valve structure in the pressure rice cooker according to claim 1.   The spacer member forms a peripheral wall as a rising portion on a flat plate portion serving as a valve seat having a through hole in the center, and forms a through hole or a cutout portion of the peripheral wall through which the steam passes, and the flat plate of the spacer member The safety valve structure in a pressure rice cooker according to claim 1, wherein the portion is attached to the inner lid as a part of the inner lid.   A heating plate to be the bottom surface of the lid is arranged below the bottom plate, which is a structural member of the lid, a protrusion is formed downward from the bottom plate, and the tip of the protrusion is inserted through the heating plate. The safety valve structure in the pressure rice cooker according to claim 1, wherein the spacer member reaches the inner lid.

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