JPH1043046A - Rice cooking jar - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat retaining condition of rice in a pan by proper temperature control in consideration of the practical use, including the opening and closing of a lid. SOLUTION: A heat retaining controller 32 sets the lower limit or higher heat retaining temperature to at least 70 deg.C, and the lower limit of lower heat retaining temperature to at least 60 deg.C for retaining the heat. Thus, even in consideration of opening and closing a lid, rice can be prevented from corruption. Also, the upper limit of the lower heat retaining temperature is set lower than 70 deg.C that in, lower than the lower limit of the higher heat-retaining temperature, so that the lower heat regaining temperature is properly utilizes to improve the heat retaining of rice in a pan. Further, the upper limit of the higher heat retaining temperature is set to at most 76 deg.C to prevent the rice from the dry.

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 improving the heat retention state of rice in a pot, and more particularly to a jar rice cooker for preventing drying and decay of rice by proper temperature control. About.

[0002]

In recent years, as a method of improving the heat retention state of rice in a pot in a jar rice cooker having this kind of heat retention function, the heat retention temperature, which is usually around 73.degree. It is known that by lowering to a certain degree, the Maillard reaction is suppressed to prevent yellowing and smell of rice and to suppress generation of warm odor due to oxidative deterioration of fatty acid.

By the way, most spoilage bacteria that spoil rice boil at a temperature of about 35 ° C. to 55 ° C., but it is known that some spoilage bacteria that multiply even at a temperature of about 65 ° C. However, if the heat retention in the low temperature state of about 60 ° C. is a short time of about 10 hours or less, the proliferation of putrefactive bacteria such as rice will not occur, so that an actual jar rice cooker has low temperature heat retention. The configuration is such that the time is kept within about 10 hours. In other words, in keeping the rice in the pot warm, maintaining the temperature of the rice at 55 ° C. or higher or 65 ° C. or higher is the borderline for preventing rot. However, in practical use,
The lid is frequently opened and closed, such as when eating rice, so that the temperature of the rice drops below the temperature at which most of the putrefactive bacteria grow, or when the lid is opened, various germs enter the pot. Because of the intrusion, existing jar rice cookers had insufficient measures to prevent putrefaction of rice in practical use.

Further, a jar rice cooker having a structure without a so-called inner lid, in which the upper opening of the pan is directly covered by a lid lower surface member forming a lower part of the lid, has no trouble of attaching and detaching the inner lid.
Because the inner lid does not need to be cleaned, it is easy to use, but since the radiant heat from the lower surface of the lid is directly radiated to the rice in the pot, the surface of the rice, in particular, tends to turn yellow, and the heat retention deteriorates There is a problem. However, if the lid heating is weakened to improve the heat retention state, condensation on the surface side of the lid lower surface member will increase, and a large amount of dew will flow when the lid is opened, and the dew holder for collecting dew Additional components are required.
In addition, when there is no dew receiving member, there is a problem that the periphery of the upper portion of the lid attaching portion of the container body is contaminated by the dew which has flowed down.

[0005] In view of the above problems at the time of heat retention, the present invention takes into account the practical aspects of the present invention taking into account the opening and closing of the lid.
It is a first object of the present invention to provide a jar rice cooker capable of improving the heat retaining state of rice in a pot by appropriate temperature management.

A second object of the present invention is to make it possible to improve the heat retaining state of rice in a pot by proper temperature management without using a dew receiving member while taking advantage of no inner lid. To provide equipment.

[0007]

According to a first aspect of the present invention, a jar rice cooker according to the present invention includes a heat retention control means for keeping rice in a pot at a plurality of predetermined temperatures to achieve the first object.
This heat retention control means sets the high heat retention temperature to 73 ± 3 ° C. and the low heat retention temperature to 65 ± 5 ° C. so that the high heat retention temperature and the low heat retention temperature are in a temperature range that does not overlap, including temperature variations. It is characterized by keeping warm.

According to the configuration of the first aspect, the lower limit of the lower temperature and the lower temperature of the upper temperature are set considering the opening and closing of the lid in consideration of the practical state. The upper limit of the lower temperature and the lower limit of the higher temperature do not overlap so that the effect of keeping the heat can be obtained. It is possible to improve the heat retention state of the rice in the pot by keeping the heat for a long time while effectively using the low heat retention while preventing the heat.

In order to achieve the second object, the jar rice cooker according to the present invention further comprises a heat-retaining control means for keeping the rice in the pot at a predetermined temperature, and the heat-retaining control means comprises: The temperature relationship between the side of the pot above the rice and the surface of the lid directly facing the pan, while the side of the pan is set lower based on the temperature of the rice, while the surface of the lid is The temperature of the lid is controlled so that the difference between the highest temperature on the surface of the lid and the lowest temperature on the side surface of the pan is within a range of 1 to 10 ° C.

According to the second aspect of the present invention, the maximum amount of rice cooked, which is estimated to be the most frequent thermal insulation for this long-time thermal insulation, is kept for a long time of about 12 hours or 24 hours. About half of the remaining rice is prevented from falling off from the lid, preventing partial sticking to the top of the rice, preventing rice from sticking around the pot skin, and removing the lid. The amount of dew flowing down from the surface of the lid when opened can be reduced, and the heat can be kept in the best condition. In addition, since the surface of the lid directly faces the pan, the ease of use due to the absence of the inner lid is utilized as it is, and without the provision of a dew receiving member, the rice in the pan can be properly temperature-controlled by proper temperature management. The heat retention can be improved.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the accompanying drawings. In FIG. 1, 1 is a rice cooker main body,
It comprises a bottomed cylindrical inner frame 2 having an open upper surface, and an outer frame 3 having the inner frame 2 therein and forming an outer shell of the rice cooker main body 1. Inside the inner frame 2 serving as a pot storage portion, a pot 4 for storing rice or water as a food to be cooked or rice as a material to be warmed at the time of heat retention is detachably provided. The pan 4 is formed in a bottomed cylindrical shape with an open upper surface, and a flange portion 5 that projects horizontally outward is provided at the upper end of the outer surface of the pan 4.
Is formed.

A heating coil 11 corresponding to a heating means for electromagnetically heating the pan 4 is provided on the outer surface of the inner frame 2 facing the bottom and the lower side of the pan 4. This heating coil
In the case 11, an alternating magnetic field is generated when a high-frequency current is supplied, and an eddy current is generated in a heating layer (not shown) of the pot 4 in the magnetic field. Then, the eddy current is converted into Joule heat, so that the heat generating layer generates heat, so that the cooked rice or the heated object in the pan 4 is heated. Also heating coil
11 heats the pan 4 with a heating output of about 100 to 600 W during the heat retention. On the other hand, a body heater 12 composed of a cord heater is provided on the outer side surface of the inner frame 2 and heats the side surface of the pan 4 with a heating capacity of about 10 to 60 W during heat retention.

Reference numeral 13 denotes a lid for opening and closing the opening on the upper surface of the pot 4. On the surface of the lid 13 directly facing the pot 4, that is, on the back side of the lid surface 14, there is provided a lid heater 15 as lid heating means composed of a cord heater.
The lid surface 14 is heated with a heating capacity of about 0 to 60 W. Further, the body heater 12 and the lid heater 15 form an electrically parallel circuit, and are configured to be simultaneously turned on and off by a cut-off control element such as a triac. A pot temperature sensor 16 corresponding to pot temperature detecting means for detecting the temperature of the pot 4 is provided substantially in the center of the outer bottom surface of the pot 4 in a contact state. Also, on the back side of the lid surface 14,
A lid temperature sensor 17 corresponding to lid temperature detecting means for detecting the temperature of the lid surface 14 is provided.

Next, the configuration of the operation panel 21 provided on the rice cooker main body 1 or the lid 13 will be described with reference to FIG.
The operation panel 21 has an LED lamp 22 and an LCD display 23 as display means at an upper part, and various switches 24 as operation means at a lower part. LED lamp
Reference numeral 22 denotes a reservation LED 22A which is turned on when a reserved rice is set, a rice cook LED 22B which is turned on during the rice cooking process, and a warming LED 22C which is turned on when the temperature is kept warm. In addition, the LCD display 23 indicates the heat retention course selected at the time of heat retention,
That is, in the present embodiment, the warming course display section 23A for displaying either the fresh warming course or the high warming course having different temperature control patterns, the display mode of “00:00” is set to 0:00 am, and the After the display format of “23:59” indicating hour and 59 minutes, “00: 0” is displayed again.
"0" appears in a 24-hour time display section 23B and a current / reservation time switch for displaying whether the display on the time display section 23B is the current time, the reserved rice setting time, or the heat retention elapsed time. And a display unit 23C. It should be noted that the fresh heat retention course displayed on the heat retention course display section 23A has a heat retention temperature of 60 to 7 temporarily.
It is provided as a heat retaining course used when the temperature is kept low at about 0 ° C. and the temperature is kept for a long time mainly. The high heat retention course is a course for keeping the temperature at a normal temperature of about 70 to 76 ° C., and is provided mainly for use when keeping the temperature for about 12 hours.

The switch 24 includes an off switch 24A for stopping all operations and turning off the operation, a rice cooker switch 24B for instructing the start of a rice cooking operation, a warming switch 24C for instructing a start of a warming operation, and a start of a reservation operation. Reservation switch 24
D, a clock switch 24E for instructing the start of adjustment of the current time or the timer time displayed on the clock display 23B of the LCD display 23;
It is provided with an hour switch 24F and a minute switch 24G for adjusting the minute. Among these, the warming switch 24C is for instructing the switching of the fresh warming course or the higher warming course, and when the warming switch 24C is pushed and operated in the off state, the warming course display section 23A displays the fresh warming course. Is displayed, and the warming operation is started. However, when the heat retaining operation is started from the cut-off state, even if the indication of the fresh heat retaining course is displayed on the heat retaining course display section 23A, the rice in the pan 4 is not actually lowered and the temperature of the lid surface 14 is lowered. Insulation control is performed. The reason is to prevent the rice from spoiling due to keeping the rice at a low temperature.
The reason for lowering the temperature of the lid surface 14 is to suppress drying of the upper surface of the rice. On the other hand, also in the case where the mode automatically shifts to the heat retention after cooking the rice, the heat retention course display unit 23A displays that it is the fresh heat retention course. At this time, assuming that the rice in the pan 4 is kept warm for a long time, the warming control is performed while combining the high and low warming temperatures. When the heat-retention switch 24C is pressed again after the heat-retention operation is started, the heat-retention course display section 23A displays a higher heat-retention course instead of the fresh heat-retention course, and the heat-retention control is performed according to this display. Change the temperature pattern of. The fresh heat preservation course is a hot pot for 6 hours immediately after cooking, taking into account the practical state of the jar rice cooker, where cooking time and meal time are closely related.
After that, the rice in the pan 4 is kept at a low temperature for 5 hours, and thereafter, the temperature of the lid surface 14 is controlled by keeping the temperature at a high temperature. Then, when the heat is kept for a long time of about 24 hours, rice is kept in a better heat-retention state than when the normal heat-retention temperature is kept high.

On the other hand, when the reservation switch 24D is pushed and operated in the OFF state, the time display section 23B and the current / reservation time switching display section 23C which have displayed the current time up to that point show the reservation time of the previous timer operation. Is displayed. Here, when the hour switch 24F or the minute switch 24G is appropriately operated, the cooking time of the reserved rice cooked displayed on the time display section 23B can be variably set in units of one minute or ten minutes.

For example, when the current time is 12:00, the longest time for which the reserved rice can be set is a position unit for setting the time for cooking from 12:00, which is 24 hours and 00 minutes after the longest timer operation time. Reduced by one or ten minutes,
11:59 to 11:50. Therefore,
When the current time is, for example, 12:05, 12:04 to 12:00 is the longest time in which reserved rice cooking can be set. Then, when the required time for cooking rice is reached, for example, 55 minutes before the reserved cooking set time, rice cooking is started, and thereafter, the operation automatically shifts to a warming operation. Further, when the time for the rice cooker is 55 minutes, the timer operation cannot be set within 55 minutes from the current time, so the time at which the reserved rice can be set is the current time (for example, 12: 0).
The time is obtained by adding 1 minute to 10 minutes, which is the minimum unit of the set time of the reserved rice cooking, to the time obtained by adding 55 minutes that is the time for the rice cooker to 0), that is, from 12:56 to 13:00.

As described above, the rice cooked by the timer operation shifts to the heat retention when the cooked time indicated by the time display section 23B is reached. Then, when the temperature is kept warm, the time display section 23B and the current / reserved time switching display section 23C switch the display to the warming elapsed time instead of the reserved rice cooking time up to that time (at this time, the current / reserved time switching display section 23C).
Prevents the display of "current time" and "reserved time" together. ), The elapsed heat retention time is displayed for 24 hours or more. This is to cope with a case in which the heat retention temperature is temporarily lowered and the heat retention time is increased to about 24 hours, as in the fresh heat retention course. It should be noted that the range of the set time of the reserved rice cooking and the series of operation control from the setting of the timer to the transition to the heat retention are performed based on the reserved rice cooking control means (not shown) stored in the microcomputer 31 described later. It has become.

Next, the functional configuration of the present invention, particularly during warming, will be described with reference to the block diagram of FIG. In FIG. 1, reference numeral 31 denotes a microcomputer, which is not shown in the drawing. In addition to a control device and an arithmetic device constituting a known microprocessor, a clock device, a ROM and an R
It comprises a storage device such as an AM and an input / output device. As one function of the microcomputer 31, there is provided a heat retention control means 32 for keeping the rice in the pot 4 at a plurality of predetermined temperatures when the heat retention switch 23C is pushed and operated after cooking or in the cut-off state. Specifically, the heat retention control means 32 controls the temperature of the pan temperature sensor 16 during the heat retention.
When the detected temperature is lower than a predetermined heat retention temperature set between 60 and 76 ° C., the pot 4 is heated by the heating coil 11 for a predetermined time (for example, 1 to 2 seconds), and thereafter, for a predetermined time (for example, 5 to 5 seconds). (10 seconds) The heating of the pan 4 is stopped. Then, after the stop of the heating for the predetermined time, the stop of the heating is continued as it is, and when the temperature becomes equal to or lower than the predetermined heat retaining temperature again during the stop of the heating, the operation of restarting the heating by the heating coil 11 is repeated. The rice in the pan 4 is kept at a predetermined temperature.
When the temperature detected by the pan temperature sensor 16 is lower than the heat retention temperature, the temperature of the lid surface 14 detected by the lid temperature sensor 17 is lower than a predetermined temperature (for example, lower than the heat retention temperature or ± 3 of the heat retention temperature). (Less than about ° C.), the lid heater 15 and the body heater 16 forming a parallel circuit are simultaneously energized to heat the side surface of the pan 4 and the lid surface 14, and the energization time is a predetermined time, for example, 20 to 80 seconds. Is passed, the heating is stopped, and the heating is stopped again until the conditions for energizing the lid heater 15 and the body heater 16 are satisfied again.

The heat retention control means 32 includes a high-temperature heat retention control means 33 for controlling the temperature of the rice at the time when the temperature is stabilized during the heat retention to a high temperature of 73 ± 3 ° C., and the temperature of the rice at the time when the temperature is stabilized during the heat retention. And a low-temperature heat-retaining control means 34 for keeping the temperature low at 65 ± 5 ° C., preferably 65 ± 3 ° C., and the heat-retaining operation is selectively performed by either one of them. The lower limit of the higher heat-retention temperature by the high-temperature heat-retention control means 33 is 70 ° C. or more, and the upper limit of the lower heat-retention temperature by the low-temperature heat-retention control means 34 is less than 70 ° C. The temperature is set to a temperature range that does not overlap or overlap.
Further, the lower limit temperature of the higher heat retention temperature is set to 70 ° C. or higher, and the lower limit temperature of the lower heat retention temperature is set to 60 ° C. or higher. In addition, it is preferable that the low-temperature keeping by the low-temperature keeping control means 34 is limited to about 10 hours as in the conventional case. The reason for this is that if the low-temperature keeping is performed for a long time of 10 hours or more, there is a risk that spoilage bacteria that spoil rice will proliferate.

Reference numeral 35 denotes a plurality of heat insulation courses each having a different temperature control pattern, and according to the temperature control pattern of a specific heat insulation course selected from these heat insulation courses, high temperature heat insulation control means 33 or low temperature heat insulation control means. 34 is a heat insulation course selecting means for selectively performing any one of the heat insulation operations. In the present embodiment, the heat insulation course selecting means 35 is configured to select either a fresh heat insulation course or a higher heat insulation course, as described above.

Next, with reference to the graphs of FIGS. 4 to 6, the relationship between the temperatures of the respective parts during the heat retention by the heat retention control means 32 will be described in detail. In each of FIGS. 4 to 6, a solid line A
Indicates the temperature of the rice in the pan 4, the dashed line B indicates the temperature of the inner surface of the pan 4 exposed above the rice (hereinafter, simply referred to as the pan side 18), and the dashed line C indicates the temperature of the lid surface 14. Is shown. The vertical axis is temperature, and the horizontal axis is time.

In the graph of FIG. 4, the period T1 in which the temperature C of the lid surface 14 is higher than the temperature A of the rice,
It is longer than the period T2 when the temperature C of the lid surface 14 is low (T1> T
2) And the difference P2 between the highest temperature C1 of the lid surface 14 and the rice temperature A is larger than the difference P3 between the lowest temperature C2 of the lid surface 14 and the rice temperature A (P2> P3). In addition, a warming operation by the warming control means 32 is performed. In this case, the temperature B of the pot side 18 hardly changes (the power consumption of the body heater 12 is extremely small, or
May not be provided. ), It is always lower than the temperature A of the rice.

On the other hand, in the graph of FIG. 5, the temperature C of the lid surface 14 is always higher than the temperature A of the rice, and the temperature B of the pot side 18 is kept equal to or lower than the temperature A of the rice. The heat retaining operation by the control means 32 is performed. FIG.
In the graph, the temperature C of the lid surface 14 is always higher than the temperature A of the rice and the temperature A of the rice is
The period T4 in which the temperature B is high is shorter than the period T3 in which the temperature B of the pot side 18 is low with respect to the temperature A of the rice (T3> T).
4) And the difference P4 between the highest temperature B1 of the pot side 18 and the temperature A of the rice is smaller than the difference P5 between the lowest temperature B2 of the pot side 18 and the temperature A of the rice (P2> P3). In addition, a warming operation by the warming control means 32 is performed. further,
4 to 6, the difference P1 between the highest temperature C1 of the lid surface 14 and the lowest temperature B2 of the pot side 18 is in the range of 1 to 10C, preferably in the range of 2 to 7C. The heat retention control means 32 is configured to be controlled. As is clear from the graphs of FIGS. 4 to 6, the heat retention control means 32
Regarding the temperature relationship between the pot side 18 and the lid surface 14, the temperature B of the pot side 18 is set to be lower while the temperature C of the lid surface 14 is set higher based on the temperature A of the rice, and the maximum temperature of the lid surface 14 is set. The difference between C1 and the minimum temperature of the pot side 18 is controlled within the range of 1 to 10 ° C, preferably within the range of 2 to 7 ° C.

By the way, it is difficult to quantitatively specify a drop in the temperature of the rice when the cover 13 is opened and closed. However, according to the results of a long-term heat retention of 24 hours or more in a practical state, the heat retention temperature of 68 ° C. was 3 out of 10 monitors.
A questionnaire result was obtained indicating that the monitor had a slight sour odor on the monitor. In addition, when the heat retention temperature of these three monitors was increased to 70 ° C., the result that all the odors were eliminated was obtained. From these points, when the opening and closing of the lid 13 is taken into consideration in keeping the heat for 24 hours or more for a long time, it is considered that setting a higher heat keeping temperature to 70 ° C. or more is one safe temperature without odor. . Considering that the maximum growth temperature of putrefactive bacteria producing sour odor is 65 ° C., the safe temperature of 70 ° C. is 5 ° C. higher than 65 ° C. Therefore, when setting a lower heat retention temperature, 5 ° C. is higher than 55 ° C. at which most putrefactive bacteria grow.
If the lower limit temperature is set to 0 ° C, the lid
Even when 13 is opened and closed, it is considered that the rot of the rice in the pan 4 can be prevented.

If the lower and higher heat retention temperatures are reversed due to temperature variations, the effect of setting the lower heat retention temperature to improve the heat retention of the rice in the pot 4 is substantially lost. Therefore, it is preferable to set the upper limit of the lower heat retaining temperature to 70 ° C. which is lower than the lower limit of the higher heat retaining temperature including the temperature variation. In addition, if the upper limit temperature of the high heat retention temperature is too high, the rice in the pan 4 will turn yellow in a short time, so that in order to prevent drying of the rice, the upper limit of the high heat retention temperature is kept at 76 ° C. or lower as in the past. Is preferably set. These points are the basis for the range between the higher heat-retention temperature and the lower heat-retention temperature in the heat-retention controller 32.

That is, in the present embodiment, there is provided a heat-retaining control means 32 for keeping the rice in the pot 4 at a plurality of predetermined temperatures. The temperature is set to 65 ± 5 ° C., and the temperature is kept so that the higher and lower temperatures are in a temperature range that does not wrap, including temperature variations. In other words, in consideration of the practical state, while setting the lower limit of each of the lower heat retaining temperature and the higher heat retaining temperature in consideration of the opening and closing of the lid 13, so as to obtain the effect of keeping the rice warm with the lower heat retaining temperature, Since the upper limit of the lower heat retention temperature and the lower limit of the higher heat retention temperature are set so as not to overlap with each other, this proper temperature control prevents the spoilage of rice due to the proliferation of spoilage bacteria,
By using the low heat retention for a long time, the pot 4
It becomes possible to improve the heat retention state of the rice inside.

By the way, when this kind of jar rice cooker is actually used, the maximum cooked amount is 1.8 liters (10 sets) and the maximum cooked amount is 1.5 liters (8.3 sets).
5 go, the maximum cooked rice amount is 1.0 liter (5.5
3), the maximum cooked amount is 0.54 liters (3
In the case of the case (2), about half of the maximum amount of cooked rice is often kept warm for a long time, such as 2 cases. This is due to the method of cooking more rice for the next meal and keeping half the amount of heat. Then, a half amount of the maximum cooked rice was stored in the pot 4 and a heat retention test was performed for 12 to 24 hours.

As a result, when the evaluation is performed based on the temperature of the rice in the pan 4, if the temperature of the pan side 18 is always higher than the temperature of the rice, or if the time during which the temperature is high is long, that is, In the graph of FIG. 5, if the relationship of T3 <T4 is satisfied), the portion of the rice in contact with the pot skin dries in a short time, and becomes crispy in a long-time heat retention.
It becomes difficult to eat. Further, when the temperature of the lid surface 14 is lower than the temperature of the rice, the dew attached to the lid surface 14 drops on the upper surface of the rice, causing a disadvantage that the rice sticks partially. However, conversely, if the temperature of the pot side 18 is too low than the temperature of the rice, the pot side 18 will condense, and the dew will flow down along the pot skin, causing a disadvantage that the rice in contact with the pot skin is sticky, If the temperature of the lid surface 14 is too high than the temperature of the rice, the radiant heat from the lid 13 is directly radiated to the upper surface of the rice, and the surface of the rice is dried and yellowed in a short time, and cannot be eaten in a long-time heat retention. It becomes a state. Furthermore, if the temperature of the pot side surface 18 is lower than the temperature of the lid surface 14 due to the fact that the temperature of the cover surface 14 is too high and no condensation occurs on the cover surface 18, condensation occurs on the pot side surface 14. Therefore, in this case, due to the dew adhering to the pot side surface 18, the portion of the rice in contact with the pot skin as described above becomes more noticeable. Further, even if dew condensation does not occur on the pot side surface 18, the amount of water released from the steam port (not shown) to the outside increases, and the drying of the rice proceeds, resulting in a disadvantage that the rice becomes hard.

As described above, when the temperature is kept for a long time, when the temperature of the rice in the pot 4 is evaluated as a reference, the temperature of the lid surface 14 and the temperature of the pot side 18 have a delicate relationship. It was necessary to experiment several times with various combinations of heating and lid heating to find the perfect balance. As a result of conducting various experiments, in order to ensure the best heat insulation state, the temperature of the pot side surface 18 was set to be low, while the temperature of the lid surface 14 was set high, and the The difference between the maximum temperature of 14 and the minimum temperature of the pot side 18 is 1 to 1
It has been found that the temperature may be in the range of 0 ° C, preferably in the range of 2-7 ° C. The reason is that if the maximum temperature of the lid surface 14 and the maximum temperature of the pan side 18 are set to a difference exceeding 10 ° C., the temperature difference between the lid surface 14 and the pan side 18 increases, and the lid surface 14
Is hot, so condensation on the lid surface 14 can be prevented as before, but the lid surface 14 is too hot and condensation is generated on the pot side 18 as much as steam generated from rice does not condense on the lid surface 14 Then, the portion of the rice in contact with the pot skin becomes sticky due to the dew flowing down from the pot side 18.

According to the results of the experiment, the heat retention condition was further improved when the difference between the maximum temperature of the lid surface 14 and the minimum temperature of the pot side surface 18 was in the range of 2 to 7 ° C. At first glance, this temperature difference seems to be better if it is small, and it seems that the best case is at 0 ° C, that is, when there is no temperature difference.
The temperature of the lid surface 13 is lower than the temperature of the rice due to the point that the temperature of the lid 13 is likely to decrease in the practical state due to the opening and closing of
Alternatively, there is a possibility that the temperature of the pot side surface 18 becomes higher than the temperature of the rice, so that a temperature difference of about 1 ° C., preferably 2 ° C. or more with a margin is provided. Furthermore, it is better to make the temperature difference 7 ° C. or less than to make the temperature difference 10 ° C. or less.
The stickiness of the rice around the pot skin was reduced, and a good heat retention state could be maintained. Also, when the lid 13 is opened,
According to the results of the experiment, the amount of dew flowing down from 14 was found to be no problem even if the dew receiving member was not provided in practice if the amount was limited to about 3 ml or less. In addition, the temperature measurement of these experimental results is evaluated based on the temperature relationship when the temperature of rice is measured in a state where the temperature of rice is stabilized at a predetermined temperature such as 65 ° C. or 73 ° C.

As described above, according to this embodiment, the pot side surface 18 above the rice and the lid surface 14 directly facing the pot 4
The temperature relationship with the rice is set such that the pot side 18 is lower than the rice temperature, the lid surface 14 is higher, and the lid surface 14 is higher.
Temperature control means 32 for controlling the temperature difference between the highest temperature of the pan and the lowest temperature of the pot side surface 18 within a range of 1 to 10 ° C., so that the heat is maintained for a long time of about 12 hours or 24 hours,
It is estimated that this is the most frequent thermal insulation that is kept for a long time, about half of the rice after the maximum amount of rice is cooked, the dew from the lid 13 is suppressed, In addition to preventing the stickiness of the rice around the pot skin, and reducing the amount of dew flowing down from the lid surface 14 when the lid 13 is opened, Can be kept warm. In addition, since the lid surface 14 has a structure directly facing the pot 4, the ease of use due to the absence of the inner lid is utilized as it is, and the rice in the pot 4 is controlled by appropriate temperature management without providing a dew receiving member. Can improve the heat retention.

By the way, as described above, this kind of conventional jar rice cooker temporarily increases the heat retention temperature, which is usually around 73 ° C., by 60 to improve the heat retention state of the rice in the pot.
It is known that by lowering the temperature to about ℃, the Maillard reaction is suppressed to prevent the yellowing and smell of rice in the pot and to prevent the generation of warm odor due to the oxidative deterioration of fatty acids. . However, those having such a function are provided with a heat retention course selection switch for switching the heat retention course and a heat retention operation start switch for starting the heat retention operation, and constitute an operation part of an operation panel. There is a problem that the number of switches is increased and it is difficult to use.

In view of the above problems, the present embodiment provides a jar rice cooker which has a function of switching a heat retention course and can improve the usability by reducing the number of switches to be operated. It is intended to be.

According to the structure of this embodiment, immediately after cooking rice, a fresh warming course for switching the warming temperature to a low temperature on the way is automatically selected and executed on the assumption that the warming is performed for a long time. If the warming time is not so long, and rather the user wants to eat hot rice, the warming switch 24C can be operated during the warming to switch to a higher warming course in which the warming is constantly performed. In addition, this insulation switch 24C
When the is operated in the off state, the heat retention control with the heat retention temperature raised is automatically performed, so that when the rice or the like is put in the pot 4, the risk of the rice being putrefactive can be prevented in advance. In addition, since the function of switching the heat retention temperature can be realized by a single heat retention switch 24C, which is a single heat retention start switch, without providing a dedicated heat retention course selection switch, the number of switches 24 forming the operation unit of the operation panel 21 can be reduced. To
It is possible to reduce the size of the operation panel 21 compared to the conventional one, simplifying the configuration of the operation panel 21 and improving the usability, and making it possible to reduce the size of the operation panel 21 and thus the rice cooker.

That is, in a rice cooker provided with a heat retention control means 32 for performing a heat retention operation by a plurality of heat retention courses having different temperature control patterns, a heat retention course selection switch for switching the heat retention course held by the heat retention control means 32 is provided. The heat insulation control means can be used also as the heat insulation switch 24C which is a heat insulation start switch for instructing the start of the heat insulation operation from the OFF state.
Even if the device 32 has a function of switching the heat retention course, it is possible to provide a jar rice cooker in which the number of switches 24 to be operated is reduced and the usability is improved. In addition, in such a configuration, when the warming operation is performed subsequent to the rice cooking, if the warming control means 32 is configured so that the warming course for temporarily lowering the warming temperature is automatically selected and executed, a long time is used. Since the heat preservation operation on the premise that the heat preservation is performed is preferentially performed, even if the heat preservation time becomes long, it is possible to eat rice in a good heat preservation state.
When the heat retention operation is started by operating the heat retention switch 24C from the OFF state, the heat retention control means 32 executes the heat retention operation to increase the heat retention temperature, thereby putting the cold rice and the like into the pot 4.
Can eliminate the risk of spoilage when placed in a container.

On the other hand, a conventional jar rice cooker of this type has a function of making a reservation of a cooking time, performing a reserved rice cooking by a timer operation, and automatically keeping warm after the rice in the pot is cooked. However, if the operation panel or the like is provided with a time display section of the reserved rice cooking time and the current time for switching between the morning and the afternoon and displaying for 12 hours, it is particularly possible to set the time of the morning and the afternoon when setting the reservation time and the current time. There was a problem that the switching was easy to make a mistake and rice was not cooked at the desired reserved cooking time.

In order to solve such a problem, there is a clock display unit which employs a 24-hour clock which does not require switching between am and pm. The maximum time that can be set is 1
Since it is restricted to about 4 hours, for example, the current time is 1
Despite wanting to set the cooking time at 10:00 the next day at 2:00, 2:00 the next day after 14 hours.
The time can only be set up to this point, and a misunderstanding or a sense of incongruity has occurred due to the fact that the reservation time can be set for only about 14 hours even though the display is 24 hours.

Therefore, in this embodiment, in consideration of such a problem, the relationship between the time display on the time display unit and the time at which reserved rice cooking can be set does not cause a sense of incongruity and does not cause misunderstanding in use. The purpose is to provide a vessel.

The time display section 23B of this embodiment displays the current time and the reserved rice cooking time without switching between AM and PM.
By displaying the time as a clock, it is possible to avoid a mistake in switching between morning and afternoon when setting the reserved rice cooking time, and it is possible to cook rice at the desired reserved rice cooking time. In addition, since the reserved cooking time can be set up to 23 hours 59 minutes, which is the maximum time that can be displayed by the time display unit 23B, the relationship between the 24-hour clock display and the time at which the reserved cooking can be set does not cause any discomfort. No misunderstanding in use. Note that this allows a timer operation of 14 hours or more. However, when it is not preferable to use the timer operation of 14 hours or more in a high temperature season such as summertime, it is necessary to prevent the timer operation from being performed for a long time. It is preferable to call attention with instructions or the like. further,
At the time of warming after reserved rice cooking, when displaying the warming elapsed time, by displaying the warming elapsed time of 24 hours or more as it is on the 24-hour clock display unit 23B,
For example, you can turn off the morning / afternoon display when keeping warm,
The troublesome display control of switching the display up to 12 hours to 24 hours becomes unnecessary, and the efficient display of the elapsed time of the heat retention can be performed.

In other words, in a rice cooker provided with a clock display section 23C for displaying the current time and the reserved rice cooking time as a 24-hour clock without switching between morning and afternoon, the maximum time during which reserved rice cooking is possible is based on the current time. 23 hours 59
If the clock display unit 23C is configured to display the reservation time so that the time is up to the minute and to display the heat retention elapsed time for 24 hours during the heat retention after the reserved rice cooking, the time of the morning / afternoon is set when the reserved rice cooking time is set. It is possible to provide a jar rice cooker that can prevent switching mistakes and that does not cause a sense of incongruity in the relationship between the time display on the time display section 23C and the time at which reserved rice can be set, and does not cause misunderstanding in use. In addition, it is possible to efficiently display the elapsed time of the heat retention after the shift to the heat retention after the cooked rice cooking for 24 hours or more, simplify the display control, and reduce the size of the clock display unit 23C. It becomes possible.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the embodiment, the jar rice cooker of the electromagnetic induction heating type is described, but a radiant heat type jar rice cooker in which the pot 4 is heated by a sheath heater or the like may be used. In addition, management of various time and temperature in the embodiment, and each switch
The operation method from 24 can be variously modified without departing from the spirit of the present invention.

[0043]

According to the first aspect of the present invention, the jar rice cooker according to the present invention includes a heat retention control means for keeping the rice in the pot at a plurality of predetermined temperatures, and the heat retention control means increases the heat retention temperature to 73 ± 3.
℃, the lower insulation temperature is 65 ± 5 ℃, and the insulation is performed so that the higher insulation temperature and the lower insulation temperature are in a temperature range that does not wrap, including temperature variations, By taking into account the practical aspects of opening and closing, etc., it is possible to improve the heat retention state of rice in the pot by proper temperature management.

Further, the jar rice cooker of the present invention according to the second aspect of the present invention is provided with a heat retention control means for keeping the rice in the pot at a predetermined temperature, the heat retention control means comprising: a side of the pot above the rice; The temperature relationship between the surface of the lid and the surface of the lid directly facing the pan, while the side of the pan is made lower on the basis of the temperature of rice, the surface of the lid is made higher, and the surface of the lid is The difference between the highest temperature and the lowest temperature on the side of the pan is 1 to
It is characterized by controlling the temperature within the range of 10 ° C, while taking advantage of the absence of the inner lid, it improves the heat retention of rice in the pan by proper temperature management without providing a dew receiving member. It becomes possible.

[Brief description of the drawings]

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

FIG. 2 is a front view of the operation panel.

FIG. 3 is a block diagram showing a functional configuration at the time of keeping the same temperature.

FIG. 4 is a graph showing a temperature relationship of each part at the time of keeping the temperature.

FIG. 5 is a graph showing a temperature relationship of each part at the time of heat retention.

FIG. 6 is a graph showing a temperature relationship of each part at the time of keeping the same temperature.

[Explanation of symbols]

 4 Pan 13 Lid 14 Surface of lid (surface of lid) 18 Pot side 32 Heat insulation control means

Claims (2)

[Claims] 1. Heat insulation control means for keeping rice in a pot at a plurality of predetermined temperatures, the heat insulation control means having a high heat insulation temperature of 73 ± 3 ° C., a low heat insulation temperature of 65 ± 5 ° C.,
The jar rice cooker is characterized in that the jar rice cooker is configured to keep the temperature so that the higher and lower heat retention temperatures are in a temperature range that does not wrap, including the temperature variation. 2. A heat retention control means for keeping the rice in the pot at a predetermined temperature, wherein the heat retention control means is provided between a side surface of the pot above the rice and a surface of a lid directly facing the pot. The temperature relationship is set such that the side of the pan is lower on the basis of the temperature of the rice, while the surface of the lid is higher, and
A rice cooker characterized in that a difference between a maximum temperature on a surface of the lid and a minimum temperature on a side surface of the pan is controlled within a range of 1 to 10C.