JP2010082091A - Rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rice cooker capable of improving the rice boiling capability by using steam without loading water into a water container and without requiring complicated work such as cleaning of a heating panel. <P>SOLUTION: The rice cooker includes at least two steam discharging paths communicating with the interior of a pot 22. A first steam discharging path 28 includes a relatively small opening to communicate with a steam port 26, and a second steam discharging path 29 communicates with the steam port 26 via a steam dew condensation part 30 and a pressure valve 31 to be opened at prescribed pressure. The steam dew condensation part 30 includes a heating means for re-evaporating dew water dripping and condensed in the steam dew condensation part. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a rice cooker that uses high-temperature steam having a temperature higher than the boiling point of water.

  In a general household rice cooker, in order to heat the rice and water in the pot, the pot heating means arranged at the bottom of the pot is the main, and the heating means in the lid is the rice and water in the pot. Since it passes through the upper space, this results in auxiliary heating. Therefore, the rice in the upper layer in the pan was insufficient in heating amount, and the rice and water in the pan could not be heated uniformly.

  In addition, in rice cooking, water is almost lost and the fluidity of rice is lost. In the steaming process, which is the final process of rice cooking, it is delicious to continue heating until then and complete the gelatinization of rice starch. Although it is indispensable to cook rice, in this process, if the heating is continued, the rice near the bottom of the pot will be burnt, so the heating is often weakened. Therefore, as a means for preventing insufficient gelatinization associated with weakening heating and improving rice cooking performance, a rice cooker that stores water in the lid in advance, generates steam from the water and promotes heating of the upper part is provided. Proposed.

  FIG. 5 shows the configuration of Patent Document 1. In FIG. 5, the rice cooker 1 has a bottomed cylindrical pot storage portion for storing the pot 2 in a detachable manner. A pan heating coil for inductively heating the pan 2 as a pan heating means 3 is provided at the bottom of the pan storage portion. Reference numeral 4 denotes a bottom temperature sensor configured to come into contact with the bottom surface of the pan 2. A pan side heating means 5 is provided with a pan side heating coil for induction heating the side surface of the pan 2. The control means 6 controls the operation of the rice cooker 1.

  In addition, a lid 7 that is pivotally supported by a hinge shaft (not shown) provided at the hinge portion at the rear of the rice cooker 1 and opens and closes the upper portion of the pan 2 is provided. The lid 7 is provided with a lid heating plate 8, and a lid heating coil for inductively heating the lid heating plate 8 is provided as the lid heating means 9. The lid heating plate 8 has a lid heating plate steam port 11, a lid steam port 12 is provided on the top surface of the lid 7, and the inside of the pan 2 communicates with the outside of the machine and is at atmospheric pressure. The steam port packing 13 is sandwiched between the lid heating plate 8 and the lid 7, and the pan packing 14 is sandwiched between the lid heating plate 8 and the flange portion on the outer periphery of the upper edge of the pan 2 when the lid 7 is closed. ing.

  Further, on the lid heating plate 8, water is stored and the steam generator 10 that generates steam by being supplied with heat from the lid heating plate 8 by heating the lid heating means 9 includes the lid heating plate 8 and the lid heating plate 8. 7. A water supply container 15 that stores water that generates steam and a water supply container lid 16 that opens and closes the upper portion of the water supply container 15 are disposed above the lid heating plate 8, particularly the steam generator 10.

Further, the steam generated in the steam generating unit 10 moves on the surface of the lid heating plate 8 through the space area surrounded by the steam port packing 13 to the steam input port 10 b and is input into the pot 2. The entire lid heating plate 8 is maintained at a predetermined high temperature. In particular, the steam temperature is maintained at 100 ° C. by generating a high temperature in the steam passage portion, and further, high-temperature steam of 100 ° C. or higher is generated. Can do.
JP 2005-160917 A

However, in the rice cooker having the above-described conventional configuration, in order to generate steam, water must be put into a water supply container, and complicated work is generated. Further, since water such as tap water is directly stored in the heating plate, minerals and the like contained in the water are deposited, and there arises a problem that the heating plate is burnt and care is complicated.

  This invention solves the said subject, It generate | occur | produces in the rice cooker main body, the pan, the pan heating means which heats the said pan, the lid | cover which covers the opening part of the said pan, and the rice cooking provided in the lid | cover. A steam outlet for releasing steam to the outside air; and a steam discharge path provided with at least two paths leading to the inside of the pan. The first steam discharge path has an opening and is connected to the steam port. The steam discharge path has a steam dew condensation part and a pressure valve that opens at a predetermined pressure, and includes a heating means that is connected to the steam port and re-evaporates the dew condensation water that has dripped onto the steam dew condensation part.

  The operation | movement by this is demonstrated. The steam generated during cooking is first discharged out of the main body through the steam outlet through the first path. When the amount of steam further increases, the internal pressure in the pan rises and the pressure valve opens, and a part of the generated steam flows into the second steam discharge path. It becomes droplet dew water and remains in the vapor dew drop. In this state, the cooking process is completed, and the steaming or heat retaining process is performed to heat the dew condensation part. When heated by the heating means, the dewdrop water becomes steam. At this time, since there is a pressure valve in the middle of the second steam path, the generated steam flows back into the pan through the second steam path as compared with the time of rice cooking, and is discharged from the first steam path to the outside of the machine body.

  From the above contents, the operation of putting water into the water container can be abolished by extracting the evaporated water from the steam during cooking. In addition, since the extracted water is steam generated during cooking of rice, it does not contain impurities such as minerals in the evaporated water, so that minerals etc. are deposited and baked on the heating plate to prevent complicated maintenance. be able to.

  The rice cooker of the present invention can improve the rice cooking performance by using steam without putting water into the water supply container and without complicated work such as cleaning the heating plate.

  Invention of Claim 1 of this invention generate | occur | produces in the rice cooker main body, a pan, the pan heating means which heats the said pan, the lid | cover which covers the opening part of the said pan, and the rice cooking provided in the lid | cover. A steam outlet for releasing steam to the outside air; and a steam discharge path provided with at least two paths leading to the inside of the pan. The first steam discharge path has an opening and is connected to the steam port. The steam discharge path has a steam dew condensation part and a pressure valve that opens at a predetermined pressure, and is provided with heating means connected to the steam port and re-evaporating the dew condensation water dripped onto the steam dew condensation part. First, the steam generated in the step passes through the first path and is discharged out of the main body through the steam discharge port. When the amount of steam further increases, the internal pressure in the pan rises and the pressure valve opens, and a part of the generated steam flows into the second steam discharge path. It becomes droplet dew water and remains in the vapor dew drop. In this state, the cooking process is completed, and the steaming or heat retaining process is performed to heat the dew condensation part. When heated by the heating means, the dewdrop water becomes steam. At this time, since there is a pressure valve in the middle of the second steam path, the generated steam flows backward in the second steam path compared to the time of rice cooking and enters the pan, and is discharged from the first steam path to the outside of the machine body. From the above, the operation of putting water into the water container can be abolished by extracting the evaporated water from the steam during cooking. In addition, since the extracted water is steam generated during cooking of rice, it does not contain impurities such as minerals in the evaporated water, so that minerals etc. are deposited and the heating plate is prevented from being burnt and maintained. Can do.

(Embodiment 1)
Embodiments of the present invention will be described with reference to FIGS. A first embodiment of the present invention will be described with reference to FIGS. 21 is a main body of the rice cooker, and is equipped with a removable pot 22. Furthermore, the lid | cover 23 which covers the upper surface of the pan 22 is installed so that opening and closing is possible. Reference numeral 24 denotes a pot coil which is a pot heating means for heating the pot 22 and a pot temperature detecting means 25 for detecting the temperature of the pot 22 inside the main body 21.

  On the lid 23. A steam port 26 that discharges steam generated during rice cooking to the outside air is provided. An inner lid 27 is provided with a first hole 27 </ b> A and a second hole 27 </ b> B for closing the upper surface of the pan 22 and discharging steam during cooking to the first steam path 28 and the second steam path 29. In the present embodiment, the first hole is set to one hole of φ2, and the second hole is set to six holes of φ3.

  The opening area of the first hole 27A is set smaller than the opening area of the second hole 27B. A first steam path 28 connects the first hole 27A and the steam port 26. Reference numeral 29 denotes a second steam path, which is connected to the steam port 26 via a steam condensing part 30 and a pressure valve 31 that are opened from the second hole 27B at a predetermined pressure.

  The steam dew condensation unit 30 is configured by providing a radiation plate 32 made of austenitic stainless steel between the inner lid 27 and the lid 23 and passing steam between the inner lid 27 and the radiation plate 32.

  Further, the pressure valve 31 is a φ12 stainless sphere having a mass of 9.5 g and closing the φ9 hole, and the valve opens and closes at a pressure of about 600 PA.

  The inner lid 27 is provided with a concave evaporation part 34 for storing condensed evaporated water. The evaporator 30 is provided with an inclination of 5 ° and the rice cooker is inclined.

  35 is a lid cover provided on the lower surface of the lid 23 and facing the radiation plate 32, and 36 is a lid coil provided in the lid cover 35. The winding has a center substantially above the center of the inner lid 27. Is a line. The lid coil 36 also forms a concave shape in accordance with the concave shape of the evaporation portion 34 of the inner lid 27.

  Reference numeral 37 denotes ferrite, which is provided on the lid coil 36 and at the position of the evaporation unit 34 at the projection position. An aluminum lid reflecting plate 38 is disposed on the lid coil 36 and the ferrite 37. Reference numeral 39 denotes a circuit board. A microcomputer (not shown) is mounted on the circuit board 39. The microcomputer controls the current for generating an alternating magnetic field in the pan coil 24 and the lid coil 36 by software.

  A lid sensor unit 40 is attached to the lid cover 35 and contacts the inner lid 27 to detect the temperature of the inner lid 27. 42 is a packing provided on the outer peripheral portion of the radiation plate 32, and the inner lids 27 and 42 constitute a second steam path by the radiation plate 32 and the packing 42.

  The operation in the above configuration will be described. The rice to be cooked and the water corresponding to the amount of the rice are put in the pan 22 and the main body 21 is decorated in a predetermined state. Next, when the user operates a rice cooking start switch (not shown), a rice cooking process is performed. The rice cooking process proceeds in each process of soaking, cooking, and steaming. In the latter half of the cooking process, the water in the pot 22 boils and steam is generated. Immediately after the steam is generated, the steam passes through the first hole 27A and is discharged from the first steam passage 28 to the outside through the steam port 26. However, as the amount of steam generated increases, the internal pressure in the pan 22 increases. To do. When the internal pressure of the pan 22 exceeds 600 PA, the pressure valve 31 operates and steam flows into the second steam passage 29 from the second hole 27B. In the second steam passage 29, a part of the steam that flows in is condensed in the steam dew condensation part 30 and stored in the evaporation part 34 of the inner lid 27 as evaporated water 33 (see steam path diagram 2). The water in the pot 22 is absorbed by the rice and the cooking process is completed. Since the amount of steam generated is reduced by suppressing the energization of the pot heating means 24, the steam generated when the pressure valve 31 is closed passes only the first steam path 30 and is discharged to the outside air.

When the unevenness process is entered, the lid coil 36 is energized. When the lid coil 36 is energized, part of the evaporating water immediately evaporates and emits steam. This generated steam flows back through the second steam path 29 and enters the pot 22 through the second hole 27B because the pressure valve 31 is closed, and then enters the first hole 27A and the first steam path 28. Is discharged to the outside air (see FIG. 3 for the steam path).

  While the steam passes through the second steam path 29, the steam is heated from the inner lid 27 and the radiation plate 32, the steam temperature becomes 100 ° C. or higher, and is discharged into the pot 22 through the second hole 27 </ b> B.

  Here, the water put in the pan at the start of cooking rice is absorbed and evaporated by the rice and almost disappears. However, a lot of moisture tends to remain at the bottom of the pot 22. In order to remove the excess moisture and promote the gelatinization of the rice, the pot 22 is also heated in the steaming process. However, since there is little moisture, when it heats from the bottom of the pan 22, the rice near the surface to which the pan 22 is heated burns. Further, the rice on the upper surface of the pot 22 is easily dried because moisture is actively evaporated. Therefore, by heating with steam from the upper surface also in the steaming step, it is possible to prevent a local temperature rise in the heating of the entire pan and drying of the rice in the upper surface and the vicinity thereof.

  The steam discharged into the pot 22 is heated to high temperature steam by the inner lid 27 and the radiation plate 32 and heats the rice and water in the pot 22, so the steam suitable for rice cooking is finer and more suitable for the rice cooking process. Generation control can be performed and delicious rice can be cooked.

  The following problems occur when the steam is generated. That is, the amount of heat required for evaporation of water is about 2257 J / g, but the constant pressure specific heat of steam is 1.9 J / g · ° C., and the amount of heat required to raise the steam temperature from 100 ° C. to 110 ° C. is 19 J / g. It becomes. In this configuration, when the inner lid 27 is heated by energization of the lid coil 36 to vaporize the evaporated water and to heat the evaporated vaporized water evenly and simultaneously, the input of the lid coil 36 is ensured to ensure the evaporation amount of the evaporated water. The amount of heat that raises the temperature of the steam when the power is applied is much smaller than the amount of heat that evaporates the evaporated water. The heat distribution varies greatly between the evaporation part 34 of the inner lid 27 and the other part, and the temperature of the steam rises too much. On the other hand, the rice on the upper surface of the pan 22 evaporates the moisture and deteriorates the taste.

  Therefore, in order to cook delicious rice, it is necessary to appropriately control the amount of evaporated water and the temperature at which steam is discharged into the pot 22 from the second hole 27B. In order to achieve the above condition, it is necessary to make the amount of heat generated per unit area of the evaporation portion 34 of the inner lid 27 larger than the amount of heat generated per unit area other than the evaporation portion 34.

  In order to solve the above problems, the present embodiment adopts the following three configurations.

  The first configuration will be described with reference to FIG. In the lid coil 36, the spatial distance Y between the inner lid 27 other than the evaporator 34 and the lid coil 36 is made wider than the spatial distance X between the inner lid 27 and the lid coil 36 in the evaporation portion 34. In the embodiment, the spatial distance X is set to 6.5 mm, and the spatial distance Y is set to 9.5 mm.

  The induced electromotive force of the inner lid 27 generated by the magnetic flux generated from the lid coil 36 is controlled by changing the spatial distance between the inner lid 29 and the lid coil 36 in the above configuration. In the above-described configuration, an induced current is generated in the inner lid 27 by the magnetic flux generated from the lid coil 36. However, if the spatial distance between the inner lid 27 and the lid coil 36 is increased, the induced current is reduced. The heat generation is small. In addition, when the spatial distance between the inner lid 27 and the lid coil 36 is short, the induced current increases, so the heat generated in the inner lid 27 increases. Therefore, by appropriately changing the spatial distance between the lid coil 36 and the inner lid 27. It is possible to control the distribution of the amount of heat generated per unit area.

Further, as a second configuration, a ferrite 37 is disposed on the upper surface of the lid coil 36 at a position facing the evaporation section 34 provided on the inner lid 27. The magnetic flux generated from the lid coil 36 in the above configuration is used to induce the induced current of the inner lid 27 while the magnetic flux of the surface facing the inner lid 27 is used. The leakage magnetic flux is not used for current induction. By providing the ferrite 37 at the location where the leakage magnetic flux is generated, the generated leakage magnetic flux passes through the ferrite 37 portion having a high magnetic permeability and returns to the lid coil 36, so that the leakage magnetic flux is reduced. As a result, the ferrite 37 is provided. Since the amount of heat generated per unit area of the inner lid 27 of the portion increases, the distribution of the amount of heat generated per unit area can be controlled by providing the ferrite 37.

  In the embodiment, Mn—Zn soft ferrite is used for the ferrite 37, but the same effect can be obtained with a material having high magnetic permeability, such as a silicon steel plate or permalloy.

  Further, in the present embodiment, the ferrite 37 is provided with the emitting portion 34, but the ferrite 37 may be provided outside the evaporation portion 34 as required.

  As a third configuration, an aluminum lid reflecting plate 38 is disposed on the lid coil 36 and the ferrite 37. When the magnetic flux generated from the lid coil 36 in the above configuration passes through the lid reflector 38, an induced current is generated in the lid reflector 38. Since the lid reflector 38 is made of aluminum and has low volumetric efficiency, heat generation is very small. Since the induced current generated from the lid reflecting plate 38 generates a magnetic flux that cancels the magnetic flux generated from the lid coil 36, the magnetic flux supplied to the inner lid 27 is also reduced, and the amount of heat generated per unit area is reduced. However, the leakage magnetic flux generated when the ferrite 37 is interposed between the lid coil 36 and the lid reflector 38 passes through the ferrite 37 having a high magnetic permeability and returns to the lid coil 36. Since the generated electromotive current is reduced, the magnetic flux that cancels the magnetic flux generated from the lid coil 36 is reduced, the magnetic flux supplied to the inner lid 27 is reduced, and the amount of heat generated per unit area is reduced. Is done. Therefore, the distribution of the amount of heat generated per unit area can be controlled by partially interposing the ferrite 37 between the lid reflecting plate 38 and the lid coil 36.

  The same effect can be obtained even if the spatial distance between the lid coil 36 and the lid reflector 38 is changed. That is, if the spatial distance between the lid reflector 38 and the lid coil 36 is increased, the induced current is reduced. In addition, when the spatial distance between the lid reflector 38 and the lid coil 36 is short, the induced current increases. Therefore, the amount of heat generated per unit area can be changed by appropriately changing the spatial distance between the lid coil 36 and the lid reflector 38. The distribution can be controlled.

  Furthermore, if the lid reflection plate 38 is arranged so as not to partially face the lid coil 36, the magnetic flux generated from the lid coil 36 is not canceled, and the amount of heat generated per unit area of the inner lid 27 can be increased. it can.

  By combining the above-described configurations, the evaporation unit 34 of the inner lid 27 cooks delicious rice by optimizing the balance between the amount of heat generated per unit area and the amount of heat generated per unit area outside the evaporation unit 34. It can be raised.

  The present invention relates to a rice cooker that uses steam having a boiling point equal to or higher than the boiling point of water in order to improve rice cooking performance.

Sectional drawing of the rice cooker in embodiment of this invention The figure which shows the flow of the steam at the time of cooking in embodiment of this invention The figure which shows the flow of the steam at the time of steaming in embodiment of this invention The positional relationship figure of the lid coil and a heating plate in embodiment of this invention Cross section of conventional rice cooker

Explanation of symbols

21 Rice Cooker Body 22 Pan 23 Lid 26 Steam Port 28 First Steam Path 29 Second Steam Path 30 Steam Condensing Section 31 Pressure Valve 34 Evaporating Section

Claims (1)

A rice cooker body, a pan, a pan heating means for heating the pan, a lid covering the opening of the pan, a steam port for releasing steam generated in the rice cooker provided on the lid, and the inside of the pan A first steam discharge path having an opening and connected to the steam port, and the second steam discharge path is opened at a predetermined temperature with the steam dew condensation part. A rice cooker having a pressure valve for re-evaporating the dewdrop water connected to the steam port and dripped onto the steam dew condensation section.

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