JPH10337248A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the power consumed in cooking rice and in keeping rice warm by efficiency heating the lower surface member of a lid. SOLUTION: A lid heater 53 is provided on the lower surface member 44 of a lid 41 covering the upper surface of a pot 4. A channel 54 is formed around the outside of the heated part of the lower surface member 44 heated by the lid heater 53. Since the cross-sectional area of the lower surface member 44 decreases at the channel 54, the amount of heat conduction to the outside from the heated part opposed to the pot 4 is reduced. Therefore, the heated part of the lower surface 44 which needs heating can be heated efficiently, and the power consumed can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jar rice cooker for both cooking and keeping warm.

[0002]

Conventionally, in such a jar rice cooker having a structure in which the lower surface member of the lid is fixed inside the lid, fixing screws and the like are provided on the lower surface of the lid, that is, on the lower surface of the lower surface member. There are advantages that they are not exposed, have a good appearance, and are excellent in cleaning properties. However, the heating of the lower surface of the lid by the lid heater provided on the back side of the lower surface member is preferable in that it can prevent dew condensation if it is performed only in a portion where steam or steam is originally opposed to the pan. The inner fixed portion is heated by heat conduction, and the heating efficiency of the lower surface member is deteriorated. Therefore, there is a problem in that heat from the lid heater is transmitted to a portion that does not need to be heated, and the amount of power consumption is unnecessarily increased during rice cooking and warming.

[0003] In view of the above problems, the present invention provides a jar rice cooker capable of efficiently heating the lower surface member of the lid to reduce the amount of power consumption during rice cooking and heat retention. For that purpose.

[0004]

In order to achieve the above object, the jar rice cooker according to the first aspect of the present invention is provided with a heating means for heating a lower surface member of a lid covering an upper surface of the pan, and a lower surface member. A groove is formed around the heating section by the heating means.

According to the first aspect of the present invention, if a groove is formed around the heating portion heated by the heating means in the lower surface member of the lid, the cross-sectional area of the lower surface member is reduced at the groove portion. As a result, the amount of heat conduction from the portion to be heated to the outside is reduced, and the heating portion that requires heating of the lower surface member can be efficiently heated.

In order to achieve the above object, a jar rice cooker according to a second aspect of the present invention is provided with a heating means for heating the lower surface member on a lower surface member of a lid covering the upper surface of the pan, and the heating means is provided with the heating means. It is arranged so as to face the upper opening of the pot, and has a groove formed substantially at the outermost periphery of the lower surface member.

According to the structure of the second aspect, the lower surface member is heated by the heating means at a portion facing the upper opening of the pot requiring heating. In addition, by forming the groove substantially at the outermost periphery of the lower surface member, the portion to be heated facing the upper opening of the pot can be efficiently heated without temperature unevenness.

[0008] The jar rice cooker according to claim 3 of the present invention comprises:
In order to achieve the object, a heating means for heating the lower surface member is provided on a lower surface member of a lid covering an upper surface of the pan, and the heating means is arranged in a state facing the upper opening of the pan, A groove is formed substantially at the outermost periphery of the lower surface member, and the depth of the groove is set to の of the material thickness of the lower surface member near the groove.
This is the one formed above.

According to the third aspect of the present invention, the lower surface member is heated by the heating means at a portion facing the upper opening of the pot requiring heating. In addition, by forming the groove substantially at the outermost periphery of the lower surface member, the portion to be heated facing the upper opening of the pot can be efficiently heated without temperature unevenness. Furthermore, the amount of heat conduction to the outside of the groove portion is at least substantially halved, so that heat conduction in portions other than the portion requiring heating can be effectively suppressed.

[0010] The jar rice cooker according to claim 4 of the present invention comprises:
In order to achieve the above object, a heating means for heating the lower surface member is provided on a lower surface member of a lid body that covers the upper surface of the pan, and an annular groove is formed on the entire outer periphery of the lower surface member. is there.

According to the structure of the fourth aspect, the cross-sectional area of the lower surface member is reduced in the groove portion, the amount of heat conduction from the portion to be heated to the outside is reduced, and the heating that requires heating of the lower surface member is required. The part can be heated efficiently. In addition, when the grooves are formed by cutting, the processing can be performed while rotating the lower surface member, so that the productivity is improved. In addition, since the amount of heat conduction can be suppressed over the entire periphery of the groove formed in the lower surface member, a heating portion that requires heating of the lower surface member can be heated very efficiently.

[0012] The jar rice cooker according to claim 5 of the present invention comprises:
In order to achieve the above object, a heating means for heating the lower surface member is provided on a lower surface member of a lid body that covers the upper surface of the pot, and a groove is formed in an outer peripheral portion of the lower surface member. A temperature detecting means for detecting the temperature of the member is provided.

According to the structure of the fifth aspect, the cross-sectional area of the lower surface member is reduced in the groove portion, the amount of heat conduction from the portion to be heated to the outside is reduced, and the heating that requires heating of the lower surface member is required. The part can be heated efficiently. Further, the temperature detecting means can detect the heat of the lower surface member not only from the lower surface but also from the side surface,
The temperature of the lower surface member can be detected with higher accuracy. Further, the temperature detecting means is securely fixed to the lower surface member only by pressing from above the temperature detecting means with an adhesive member such as a double-sided tape, so that the mountability is improved. Further, since the portion where the groove is formed is thinner than the other portions, the accuracy of detecting the temperature of the surface of the lower surface member facing the pot is improved, and the detection of boiling and prevention of dew condensation can be reliably controlled.

The jar rice cooker according to claim 6 of the present invention comprises:
In order to achieve the above object, the lower surface member of the lid covering the upper surface of the pot is formed by solidifying molten aluminum such as die casting or melt forging into a predetermined shape, and this lower surface member is formed on the lower surface member of the lid. A heating means for heating the member is provided, and a groove formed by cutting is formed on the lower surface member located outside the heating means.

According to this configuration, if a groove is formed on the lower surface member of the lid body outside the heating section heated by the heating means, the cross-sectional area of the lower surface member is small at the groove portion. As a result, the amount of heat conduction to the outside of the heating unit is reduced, and the heating unit can be efficiently heated. As a result, it is possible to reduce the amount of power consumption during rice cooking and during heat retention. In addition, the lower surface member is formed by a molding method such as die casting or molten metal forging.
Since the molten aluminum is solidified in the mold to form a predetermined shape, the thickness of the portion to which the heating means is attached can be arbitrarily thick. Therefore, this portion can be uniformly heated with good heat distribution, and the lower surface member can be heated without unevenness in temperature during rice cooking or heat retention. In addition, since the lower surface member other than the groove is formed in a predetermined shape at the time of molding, the groove is formed by cutting, so that the thickness of the lower surface member can be arbitrarily increased at the time of molding, but the moldability is deteriorated. In addition, the depth and width of the groove can be formed with high dimensional accuracy.

[0016] The rice cooker according to claim 7 of the present invention comprises:
In order to achieve the above object, a heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pan, and a fixing portion for fixing the lower surface member to the lid is provided inside the lid. The thickness of the material at the fixing portion of the lower surface member is partially reduced.

According to the seventh aspect of the present invention, since the material thickness of the fixing portion of the lower surface member is partially reduced, the cross-sectional area of the lower surface member is reduced at this portion, so that the lower portion is located outside the thin portion. , The amount of heat conduction is reduced, so that the heating portion that requires heating of the lower surface member can be efficiently heated. In addition, since the amount of heat conduction from the fixing portion of the lower surface member to the lid can be reduced, even if the fixed portion of the lid to which the lower surface member is fixed is formed of, for example, plastic such as polyethylene, the amount of heat transferred from the lower surface member is reduced. Thermal degradation due to heat conduction can be prevented.

The jar rice cooker according to claim 8 of the present invention comprises:
In order to achieve the above object, a heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pan, and a fixing portion for fixing the lower surface member to the lid is provided inside the lid. And a material cut portion formed by partially cutting the material at a portion other than the fixed portion of the lower surface member.

According to the structure of the eighth aspect, the volume occupied by the lower surface member inside the lid is reduced by the formation of the material cut portion, and the heat guided by the heat conduction from the heating means is reduced. The surface area radiated inside is also reduced. Therefore, the lower surface member can reduce unnecessary heat radiation other than the facing surface on the pot side to be heated, and can increase the heating efficiency. Also, the weight of the lower surface member and thus the lid can be reduced,
It is possible to contribute to a reduction in body weight.

[0020] The jar rice cooker according to claim 9 of the present invention comprises:
In addition to the configuration of the seventh or eighth aspect, the shape of the lower surface member is formed by previously solidifying molten aluminum such as die casting or molten metal forging.

According to the ninth aspect of the present invention, a partial thin portion as described in claim 7 or a partial material cut portion as defined in claim 8 is formed in advance with a mold according to its shape. By manufacturing and molding, a desired shape can be realized with almost no post-processing, and the productivity of the lower surface member can be improved.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a jar rice cooker according to the present invention will be described below with reference to FIGS. In FIG. 1, reference numeral 1 denotes a vessel main body, and 2 denotes an outer frame which forms an outer shell of the vessel main body 1. A bottom plate 3 is fitted and fixed to an open bottom lower end of the outer frame 2. Further, inside the outer frame 2, a bottomed cylindrical inner frame 5 that accommodates the pan 4 in a detachable manner is disposed. The inner frame 5 is configured by connecting an inner frame upper portion 6 integrated with the outer frame 2 and a coil base 7 forming a lower portion of the inner frame, which is a separate component from the outer frame 2. Then, the bottomed cylindrical pot 4 that accommodates a cooked product such as rice or water during rice cooking and a warmed product such as rice during warming is housed in the inner frame 5 so as to be insertable and removable inside. Is done.

The pot 4 is joined to a pot body 11 mainly made of a material having good heat conductivity such as aluminum, and is joined to a bottom surface and a lower portion of a side surface of the pot body 11, and is made of a magnetic material such as ferritic stainless steel. And a heating element 12 made of a metal material. A flange 13 protruding in a substantially horizontal direction is formed at the upper end of the pan 4. When the pan 4 is accommodated in the inner frame 5, the flange 13 rests on the upper end of the inner frame 5 to suspend the pan 4. It is designed to be supported in the installed state. At this time, a gap 14 is formed between the outer surface of the pan 4 and the inner surface of the inner frame 5, and the smaller the gap 14, the more preferable the heat transfer of the pan 4 is suppressed. 15 is the coil base 7
Is a pot temperature sensor serving as a pot temperature detecting means provided at the center of the bottom of the pot, which is in contact with the outer bottom surface of the pot 4, and constantly detects the temperature of the cooked rice or the warmed food in the pan 4 It has become.

Reference numeral 21 denotes a heating coil serving as a pan heating means provided on the outer surface of the coil base 7. This heating coil 21
Is spirally wound around the outer surface of the pan 4 in a state of facing the heating element 12 and fixed. A coil cover 22 for fixing the heating coil 21 to the coil base 7 is mounted outside the heating coil 21, and a ferrite for preventing leakage of magnetic flux from the heating coil 21 is provided outside the coil cover 22. The member 23 is mounted. Reference numeral 24 denotes a body heat insulating plate fixedly formed outside the inner frame upper portion 6 facing the side surface of the pan 4 while forming a heat insulating space.

In the outer frame 2, a heating substrate 25 is provided below the ferrite member 23. This heating substrate 25
In each case, a heating board unit 26 constituting a control circuit of the heating coil 21 and a switching element 27 as a heat generating component are mounted. The heating board unit 26 includes an inverter circuit and the like, and supplies a predetermined high-frequency current to the heating coil 21. By supplying the high-frequency current, a magnetic field is generated in the heating coil 21, and the heating element 12 of the pan 4 is heated by electromagnetic induction heating to heat the pan 4. It is the same as a jar type insulated pot.
Further, between the switching element 27 for generating a high-frequency current and the heating substrate 25, a radiator plate 29 having a large number of fins 28 formed downward is attached in a state of being in close thermal contact. The lower ends of the fins 28 face the ventilation holes 30 formed in the bottom plate 3, and are configured to circulate heat with the outside air here.

Reference numeral 31 denotes a substrate provided inside the front portion of the outer frame 2. A power supply unit 32 forming a power supply circuit is provided on the substrate 31 downward, and a display operation unit 33 including display means (not shown) such as LCD and LED and operation means including various switches is provided. , Is provided to face an operation panel 34 mounted on the front surface of the outer frame 2.
Reference numeral 35 denotes a code reel provided inside the rear portion of the outer frame 2 for winding a power cord (not shown).

Reference numeral 41 denotes a lid that directly covers the upper opening of the pot 4. The lid 41 is made of a plastic resin material such as polypropylene, and an outer lid 42 forming an outer surface of the lid 41,
An outer lid cover 43 made of a plastic resin material such as polypropylene, which is formed on the lower outer periphery of the lid 41 and does not face the upper opening of the pan 4 and is fitted to the lower outer periphery of the outer lid 42; And a lower surface member 44 that forms a portion of the lower surface of the lid 41 that faces the upper opening of the pot 4. Lid
As shown also in FIG.
A flange-shaped fixing portion 45 having a character shape is formed on the outer peripheral portion. The fixing portion 45 is for fixing the lower surface member 44 to the outer lid cover 43 of the lid 41 inside the lid 41, and the horizontal portion of the fixing portion 45 has the material thickness partially reduced. A groove-shaped thin portion 45A is formed. A hole 47 through which a fixing screw 46 is inserted is formed in the thin portion 45A, and the fixing screw 46 is screwed into a fixed portion 48 formed inside the outer lid cover 43 so that the outer lid cover 43 is Bottom member
Fixation with 44 is achieved. A base 50 having a hole 49 at the center is formed at a portion other than the fixing portion 45 which forms the outer peripheral portion of the lower surface member 44. The lower surface of the base 50, that is, the surface that is exposed when the lid 41 is opened, is formed in a flat shape in which fixing screws and the like are not exposed. As a result, the appearance and the cleanability when the lid 41 is opened are favorably maintained.

The lower surface member 44 is formed in a predetermined shape by aluminum die casting or molten metal forging. In such a molding method, the molten aluminum is cooled in a mold (not shown) and solidified to form a predetermined shape.
44 can be made relatively thick. On the upper surface of the lower member 44, that is, on the back surface that does not face the upper opening of the pan 4,
A lid heater 53 in which a cord-shaped heater 51 is covered with an aluminum foil 52 and arranged in a predetermined pattern is attached and fixed using an adhesive member such as a double-sided tape (not shown). The lid heater 53 corresponds to a heating unit that heats the lower surface member 44 of the lid body 41 during cooking and keeping the temperature, and is configured to prevent dew condensation on the lower surface member 44.

The lid heater 53 is disposed substantially radially from the center of the lower surface member 44 in a state facing the upper opening of the pot 4, and is disposed around the heating portion of the lower surface member 44 heated by the lid heater 53. The groove 54 is formed. This groove 54 is
Although it is formed on the inner side of the fixing portion 45 on the outermost periphery of the lower surface member 44, it is preferable to provide it on the outermost periphery of the lower surface member 44. The average material thickness a where the lid heater 53 is arranged is 1.5 mm, preferably 2 mm.
５5 mm. In this embodiment, the material thickness a near the groove 54 equal to the average material thickness of the lower surface member 44 is set to 3 mm, and the material thickness b of the flat portion of the base 50 where the lid heater 53 is arranged is set to 4 mm. When the average material thickness a of the lower surface member 44 is 3 mm, it is preferable to set the depth c of the groove 54 to 1/2 or more, for example, to set the depth c to 1.5 to 2.0 mm. However, if the groove 54 is too deep, the strength of the lower surface member 44 cannot be maintained.
It is necessary to make the material thickness of 0.6 mm or more. In this embodiment,
The depth c of the groove 54 is formed to be 1.8 mm, and the thickness of the lower surface member 44 at the groove 54 is 1.2 mm.

As shown in FIG. 3, the groove 54 is formed in an annular shape over the entire outer periphery of the lower surface member 44. Also, groove 54
Are formed on both sides thereof, and in this embodiment, the width d of the inclined surface 55 is formed to be 3 mm. further,
The width e at the top of the groove 54 is formed to be 2.5 mm. The shape of the groove 54 is formed by forming the lower surface member 44 into a predetermined shape and then performing a cutting process such as a lathe process. The width of the groove 54 is not particularly limited, but is preferably set to be about 1 to 3 mm in consideration of workability. The surface of the lower member 44 is
Painted with fluorine-based paint. In addition, instead of die-casting the lower surface member, after pressing and forming an aluminum plate or stainless steel plate of about 1 to 3 mm,
The grooves 54 may be formed by cutting. Further, the groove 54 may be formed on the surface of the lower surface member 44 facing the pot 4 as shown in FIG. However, considering the good cleaning performance of the lower surface member 44, it is preferable to form the groove 54 on the back surface of the lower surface member 44 because the surface of the lower surface member 44 becomes flat.

On the back side of the lower surface member 44, a lid temperature sensor 56 as temperature detecting means for detecting the temperature of the lower surface member 44 is provided. The lid temperature sensor 56 may be provided inside the groove 54 as shown in FIG. In this case, when the temperature sensor 56 is covered with an aluminum foil 57 having an adhesive member such as a double-sided tape adhered to the lower surface, the temperature sensor 56 can be fixed in the groove 54. Then, the temperature information from the temperature sensor 56 is received, and while the power of the lid heater 53 is controlled to be cut off, the temperature of the lid 41, in particular, the lower surface member 44 is controlled.

As shown in FIG. 3, the lower surface member 44 has a shape in which a material cut portion 58 is formed by partially cutting the material from a conventional outer shape (shown by a broken line) having a substantially disk shape. ing. The outer shape of the lower surface member 44 in the present embodiment is as shown by a solid line in FIG. That is, the material cut portion 58 is formed on the outer peripheral portion of the lower surface member 44 excluding the fixing portion 45 to the lid 41. The shape of the lower surface member 44, including the material cut portion 58 and the thin portion 45A formed in the fixing portion 45, is preferably formed by previously solidifying molten aluminum such as die casting or molten metal forging.

Inside the cover 41, a cover lower surface heat shield plate 61 for blocking heat from the lower surface member 44 is provided so as to cover the back surface of the lower surface member 44. Further, another outer cover heat shield plate 62 is provided inside the outer cover 42. Between the outer lid cover 43 and the lower surface member 44 is formed of an annular elastic body, and when the lid 41 is closed,
A lid packing 63 whose lower part is in close contact with the upper surface of the pan 4 is provided. The lid 41 is pivotally supported on one side of the container main body 1, and a spring (not shown) for urging the lid 41 in a direction in which the lid 41 is always opened is disposed on the hinge 64 serving as a pivot. Then, when the clamp button 65 for locking the lid 41 provided on the opposite side of the hinge 64 is released, the lid 41 is automatically opened.

The upper surface of the outer lid 42 is provided with a concave portion 71 depressed toward the pot 4 side. The hole 49 of the lower surface member 44 corresponding to the center of the concave portion 71 has a cylindrical portion 73 forming a lower portion of the steam port 72.
And a concave portion 71 located around the hole 49.
Is sealed by a silicone rubber vapor port packing 74 between the bottom rear side of the bottom surface member and the rear surface of the lower surface member 44. Steam port 72
Are formed of a steam port cap 75 and a steam port case 76, each of which is made of, for example, polypropylene resin having excellent steam resistance. Mounted as possible.

Next, the operation of the above configuration will be described. When cooking rice, the lid 41 is opened, the pot 4 containing rice and water is stored in the inner frame 5 of the container body 1, and the lid 41 is closed. In this state, the surface of the lower surface member 44 of the lid 41 directly covers the upper opening of the pot 4. Then, when the cooker is started by operating a switch on the operation panel 34, the heating element 12 of the pan 4 generates heat by energizing the heating coil 21 with high frequency, and this pan 4
Is heated. The heating of the pan 4 is controlled according to the temperature of the pan 4 detected by the pan temperature sensor 15. After the completion of rice cooking, the rice in the pan 4 is kept at a predetermined temperature by heating the pan 4 by high-frequency power supply to the same heating coil 21. The heating by the lid heater 53 prevents the formation of dew on the surface of the lower surface member 44 of the lid 41 from the time of cooking to the time of keeping the temperature.

It is known that the amount of heat conduction of a substance is proportional to the cross-sectional area of the substance, and the smaller the cross-sectional area, the lower the amount of heat conduction. Therefore, the lower surface member of the lid 41
44, if a groove 54 is formed around the outside of the heating section heated by the lid heater 53, the lower surface member 44
Is reduced, the amount of heat conduction from the portion to be heated facing the pot 4 to the outside is reduced, and the heating portion that needs to heat the lower surface member 44 can be efficiently heated. That is, the lower surface member 44 of the lid 41 that covers the upper surface of the pan 4
In a jar rice cooker provided with a lid heater 53 serving as a heating means for heating the heater, if the groove 54 is formed around the heating portion of the lower surface member 44 by the lid heater 53, the portion to be heated can be efficiently heated, and It is possible to reduce the amount of power consumption during heat retention.

In this case, if the fixing portion 45 for fixing the lower surface member 44 to the lid 41 is formed outside the heating portion of the lower surface member 44, that is, outside the groove 54, the fixing portion 45 is fixed to the fixing portion 45. Since the amount of heat conduction is reduced and the temperature rise of the fixing portion 45 can be reduced, even if the outer cover 43 forming the fixed portion 48 of the lid 41 is formed of a heat-sensitive plastic material, this outer cover 43
Can be obtained a heat protection effect.

When the groove 54 is formed near the center of the lower surface member 44, the temperature rise outside that portion is suppressed, so that temperature unevenness occurs in the lower surface member 44 facing the upper opening of the pot 4. The temperature of the portion outside the groove 54 becomes lower.
Therefore, in order to prevent temperature unevenness of the lower surface member 44, the lid heater 53 is disposed so as to face the upper opening of the pan 4,
Grooves on the outermost periphery of the lower surface member 44 as much as possible, that is, almost the outermost periphery
54 may be formed. With this configuration, the lower surface member
44 is a portion facing the upper opening of the pan 4 which needs heating,
Heating is performed by the lid heater 53, and the groove 54 is formed substantially at the outermost periphery of the lower surface member 44, so that the portion to be heated facing the upper opening of the pan 4 can be heated uniformly and efficiently. Heating can be performed, and it is possible to reduce the amount of power consumption during cooking and keeping warm.

In such a configuration of the lower surface member 44, the groove
If the depth of the groove 54 is too shallow, the effect of suppressing heat conduction to the outside of the groove 54 will be reduced. Therefore, in the present embodiment, the depth of the groove 54 is formed to be １ ／ or more of the material thickness of the lower surface member 44 near the groove 54. In this way, the amount of heat conduction to the outside of the groove 54 is reduced at least approximately by half, and the heat conduction of a portion requiring heating can be effectively suppressed. Also, if the material thickness of the lower surface member 44 in the groove 54 is 0.6 mm or more,
As 44, the practical strength that has been proven in the past can be maintained, and the reduction in practical strength due to the formation of the groove 54 can be prevented. At this time, after forming the lower surface member 44 into a predetermined shape, if the grooves 54 are formed by cutting, without adversely affecting the formability of the lower surface member 44 during manufacturing,
The depth of the groove 54 can be accurately controlled.

In this embodiment, an annular groove 54 is formed on the entire outer periphery of the lower surface member 44. This way,
The cross-sectional area of the lower surface member 44 is reduced at the groove 54, and the amount of heat conduction from the portion to be heated to the outside is reduced.
The heating section that requires 44 heating can be efficiently heated. Further, when the grooves 54 are formed by cutting such as lathe processing, the processing can be performed while rotating the lower surface member 44 of the lid 41, and the productivity is improved. Furthermore, since the amount of heat conduction can be suppressed over the entire periphery of the groove 54 formed in the lower surface member 44, the heating portion that requires heating of the lower surface member 44 can be heated very efficiently, and the amount of power consumption during rice cooking and heat retention Can be further reduced.

In this embodiment, the groove 54 is formed on the outer peripheral portion of the lower surface member 44.
In the groove 54, a lid temperature sensor 56 is provided as temperature detecting means for detecting the temperature of the lower surface member 44. In this way, the cross-sectional area of the lower surface member 44 is reduced at the groove 54, the amount of heat conduction from the portion to be heated to the outside is reduced, and the heating unit that needs to heat the lower surface member 44 is efficiently heated. it can. Further, conventionally, since the lid temperature sensor is provided on the rear flat surface of the lower surface member, the contact portion with the lower surface member is only on the lower side of the lid temperature sensor. However, in this embodiment, since the lid temperature sensor 56 is provided in the groove 54, the heat of the lower surface member 44 can be detected not only from the lower surface but also the side surface of the lid temperature sensor 56, and the temperature of the lower surface member 44 can be detected more accurately. Detection can be performed. Further, the lid temperature sensor 56 is securely fixed to the lower surface member 44 only by pressing the lid temperature sensor 56 from above with an adhesive member such as a double-sided tape, so that the mounting property is improved. Further, since the thickness of the portion where the groove 54 is formed is thinner than other portions, the accuracy of detecting the temperature of the surface of the lower surface member 44 facing the pot 4 is improved, and the detection of boiling and prevention of dew condensation are performed. Can be controlled reliably.

The lower surface member 44 of this embodiment is formed by solidifying molten aluminum in a mold by a molding method such as die casting or molten metal forging to form a predetermined shape.
The material thickness of the base 50 of the lower surface member 44 to which the lid heater 53 is attached can be arbitrarily increased. Therefore, the portion to which the lid heater 53 is attached can be uniformly heated with good heat distribution, and the lower surface member 44 can be heated without unevenness in temperature during rice cooking or heat retention. Also, when the groove 54 is formed by a convex portion of a mold during molding, the flow of a molding method such as a locally melted aluminum die casting or a molten metal forging method is deteriorated, and the moldability is extremely deteriorated. Since the lower surface member 44 other than the groove 54 is formed in a predetermined shape in advance by a molding method such as the die casting method or the molten metal forging method, the groove 54 is formed by cutting. While the thickness can be arbitrarily increased, there is an advantage in manufacturing that the depth and width of the groove 54 can be formed with high dimensional accuracy without deteriorating the formability.

That is, the lower surface member 44 of the lid 41 that covers the upper surface of the pan 4 is formed by solidifying molten aluminum such as die casting or molten metal forging into a predetermined shape. If a lid heater 53 is provided as a heating means for heating the lower surface member 44 and a groove 54 is formed in the lower surface member 44 located outside the lid heater 53 by cutting, the lower surface member 44 of the lid body 41 can be efficiently used. By heating well, it is possible to reduce the amount of power consumption during cooking and keeping warm. In addition, since the thickness of the lower surface member 44 can be arbitrarily increased at the time of molding,
The temperature distribution of the portion where the lid heater 53 is attached is improved, the lower surface member 44 can be heated without temperature unevenness, and the depth and width of the groove 54 can be formed with high dimensional accuracy without impairing the formability.

In this embodiment, a fixing portion 45 for fixing the lower surface member 44 to the lid 41 is provided inside the lid 41, and the material thickness of the fixing portion 45 of the lower surface member 44 is partially reduced. Has formed. By doing so, the thin portion 45A of the lower surface member 44 is formed.
, The amount of heat conduction to the outside of the thin portion 45A is reduced, and the heating portion that requires heating of the lower surface member 44 can be efficiently heated. Also, the lower surface member 44
Since the amount of heat conduction from the fixing portion 45 to the lid 41 can also be reduced,
The fixed portion 48 of the lid 41 to which the lower surface member 44 is fixed is an outer lid cover 43 made of plastic such as polyethylene.
Even if it is formed, thermal degradation due to heat conduction from the lower surface member 44 can be prevented.

In this embodiment, a fixing portion 45 for fixing the lower surface member 44 to the lid 41 is provided inside the lid 41, and the material is partially applied to portions other than the fixing portion 45 of the lower surface member 44. A cut material cut portion 58 is formed. This way,
The volume occupied by the lower surface member 44 inside the lid 41 is reduced by the formation of the material cut portion 58, and heat guided by heat conduction from the lid heater 53 serving as a heating means is radiated into the lid 41. The reduced surface area is also reduced. Therefore, the lower surface member 44 can reduce unnecessary heat radiation other than the facing surface on the side of the pot 4 to be heated, and can increase the heating efficiency. Becomes possible. Further, the weight of the lower surface member 44 and thus the lid 41 can be reduced, which can contribute to the reduction of the body weight.

A partially thin portion formed on the fixing portion 45
The shape of the lower surface member 44, including 45A and the material cut portion 58 formed on the outer periphery, is preferably formed by solidifying molten aluminum in advance by die casting or molten metal forging.
In this case, the thin portion 45A and the material cut portion 58 are formed in advance by forming a mold in accordance with the shape thereof and molding the same.
A desired shape can be realized with almost no post-processing, and the productivity of the lower surface member 44 can be improved.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, the heating means of the lid is not limited to the electrothermal cord-shaped heater as in this embodiment. For example, the lower surface member may be formed of ferritic stainless steel, and the heating coil provided on the upper surface of the lower surface member may be applied to an electromagnetic induction heating type heating means for induction heating the lower surface member. In this case as well, a groove may be formed around the heating portion of the lower surface member facing the heating coil.

As a modified example, the present invention can be applied to a pot heater for heating the bottom of the pot. That is, this type of heater usually has a configuration in which a sheathed heater or a mica heater is incorporated in an aluminum die-cast component, a pot is placed on the upper surface of the aluminum die-cast component, and the pot is heated to cook rice. Therefore, if a groove is formed on the outer periphery of the heat source, the amount of heat conduction to the outer peripheral portion not in contact with the pan is suppressed,
The heating efficiency for the pot is improved.

[0049]

According to the first aspect of the present invention, a jar rice cooker is provided with a heating means for heating a lower member of a lid covering an upper surface of a pot, and a groove is formed around a heating portion by the heating means of the lower member. Therefore, it is possible to efficiently heat the lower surface member of the lid to reduce the amount of power consumption during rice cooking and heat retention.

The rice cooker according to the second aspect of the present invention is
A heating means for heating the lower surface member is provided on the lower surface member of the lid covering the upper surface of the pan, and the heating means is arranged in a state facing the upper opening of the pan, and substantially the outermost periphery of the lower surface member. The heating target portion of the lower surface member of the lid, particularly the portion facing the upper opening of the pan, is uniformly heated and efficiently heated, so that the amount of power consumption at the time of cooking rice and keeping the temperature warm is formed. Reduction can be achieved.

The jar rice cooker according to the third aspect of the present invention comprises:
A heating means for heating the lower surface member is provided on the lower surface member of the lid covering the upper surface of the pan, and the heating means is arranged in a state facing the upper opening of the pan, and substantially the outermost periphery of the lower surface member. A groove is formed, and the depth of the groove is formed to be 以上 or more of the material thickness of the lower surface member in the vicinity of the groove,
It is possible to heat the portion of the lower surface member of the lid, particularly the portion to be heated facing the upper opening of the pan, without temperature unevenness and efficiently, and to reduce the amount of power consumption during cooking and keeping warm. In addition, heat conduction in portions other than those requiring heating can be effectively suppressed.

The jar rice cooker according to the fourth aspect of the present invention comprises:
A heating means for heating the lower surface member is provided on a lower surface member of the lid that covers the upper surface of the pot, and an annular groove is formed around the entire outer peripheral portion of the lower surface member. Heating can be performed very efficiently, and it is possible to further reduce the amount of power consumed during cooking and keeping warm. Further, the productivity in forming the groove in the lower surface member can be improved.

The jar rice cooker according to claim 5 of the present invention comprises:
A heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pot, and a groove is formed in an outer peripheral portion of the lower surface member, and a temperature detector for detecting the temperature of the lower surface member in the groove. Means are provided, and it is possible to efficiently heat the lower surface member of the lid, and to reduce the amount of power consumption at the time of cooking rice or keeping the temperature. In addition, the temperature of the lower surface member can be accurately detected, and the attachment of the temperature detecting means can be improved. Further, since the accuracy of detecting the temperature of the lower surface member, particularly the surface facing the pan, is improved, it is possible to reliably control the detection of boiling and prevention of dew condensation.

The jar rice cooker according to claim 6 of the present invention is
The lower surface member of the lid covering the upper surface of the pot is formed by solidifying molten aluminum such as die casting or melt forging into a predetermined shape, and the lower surface member of the lid is provided with heating means for heating the lower surface member. A groove is formed by cutting on the lower surface member located outside the heating means, and the lower surface member of the lid is efficiently heated to reduce power consumption during rice cooking and heat retention. Becomes possible. Also,
Since the thickness of the lower surface member can be arbitrarily increased at the time of molding, the lower surface member can be heated without temperature unevenness, and the depth and width of the groove can be formed with high dimensional accuracy without impairing the formability.

The jar rice cooker according to claim 7 of the present invention is
A heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pan, and a fixing portion for fixing the lower surface member to the lid is provided inside the lid, and a fixing portion for the lower surface member is provided. In this case, the thickness of the material is partially thinned, and the lower surface member of the lid can be efficiently heated to reduce the amount of power consumption during cooking and keeping warm.
Further, by reducing the amount of heat conduction from the fixing portion of the lower surface member to the lid, thermal degradation of the lid can be prevented.

The jar rice cooker according to claim 8 of the present invention comprises:
A heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pan, and a fixing portion for fixing the lower surface member to the lid is provided inside the lid, and a fixing portion for the lower surface member is provided. In other parts, the material cut part is formed by partially cutting the material, and it is possible to efficiently heat the lower surface member of the lid and reduce the power consumption during cooking and keeping warm. become. Further, the weight of the main body can be reduced.

A jar rice cooker according to claim 9 of the present invention is
In addition to the structure of claim 7 or 8, the shape of the lower surface member is formed by solidifying in advance a molten aluminum such as die casting or molten metal forging, thereby improving the productivity of the lower surface member. It becomes possible.

[Brief description of the drawings]

FIG. 1 is an overall sectional view of a jar rice cooker showing one embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the above.

FIG. 3 is a partial plan view of a lower surface member of the upper cover.

FIG. 4 is a sectional view of a main part showing another example.

FIG. 5 is a sectional view of a main part showing still another example.

[Explanation of symbols]

 4 Pan 41 Lid 44 Lower surface member 45 Fixed part 45A Thin part 53 Lid heater (heating means) 54 Groove 56 Lid temperature sensor (temperature detecting means) 58 Material cutting part

Claims (9)

[Claims] 1. A jar rice cooker comprising a heating means for heating a lower surface member of a lid covering an upper surface of a pot, and a groove formed around a heating portion of the lower surface member by the heating means. 2. A heating means for heating the lower surface member is provided on a lower surface member of a lid body which covers an upper surface of the pan, and the heating means is arranged so as to face an upper opening of the pan and the lower surface member. A jar rice cooker characterized by forming a groove around the outermost periphery of the jar rice cooker. 3. A lower surface member of a lid that covers an upper surface of the pot is provided with a heating means for heating the lower surface member, and the heating means is arranged so as to face an upper opening of the pan and the lower surface member is provided. A jar rice cooker characterized in that a groove is formed substantially at the outermost periphery of the jar, and the depth of the groove is formed to be at least half the material thickness of the lower surface member near the groove. 4. A heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pot, and an annular groove is formed on the entire outer peripheral portion of the lower surface member. Jar rice cooker. 5. A heating means for heating the lower surface member is provided on the lower surface member of the lid covering the upper surface of the pot, and a groove is formed in an outer peripheral portion of the lower surface member. A rice cooker provided with a temperature detecting means for detecting the temperature. 6. A lower surface member of a lid which covers an upper surface of a pot is formed by solidifying molten aluminum into a predetermined shape by die casting or molten metal forging, and heating the lower surface member to the lower surface member of the lid. A jar rice cooker characterized in that a heating means is provided, and a groove is formed by cutting in the lower surface member located outside the heating means. 7. A heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pot, and a fixing portion for fixing the lower surface member to the lid is provided inside the lid. A jar rice cooker characterized in that a material thickness in a fixing portion of a lower surface member is partially thinned. 8. A heating means for heating the lower surface member is provided on a lower surface member of the lid covering the upper surface of the pot, and a fixing portion for fixing the lower surface member to the lid is provided inside the lid. A jar rice cooker characterized in that a material cut portion obtained by partially cutting a material is formed in a portion other than a fixing portion of a lower surface member. 9. The shape of the lower surface member is formed by previously solidifying molten aluminum such as die casting or molten metal forging.
Jar rice cooker as described.