JP2002065455A - Rice cooker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rice cooker which can cook rice with high quality in a heating state which is similar to the fire form of Kamado(an old-style Japanese kitchen range). SOLUTION: A side part coil 13 which surrounds the wall of an inner cooker 3 is so formed that an upper convex bending part Bu and a lower concave bending part Bd are arranged alternately as a wave form along the circumference direction. Because of this, heating can be performed to the wider range of vertical direction, and also it becomes possible to create a heating state which is similar to the fire form of Kamado and uniform and high quality rice can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rice cooker of an electromagnetic induction heating type (hereinafter referred to as IH type).

[0002]

2. Description of the Related Art As shown in FIG. 6, for example, a conventional IH type rice cooker includes a rice cooker body 51, a lid 52 for opening and closing an upper opening of the rice cooker body 51, and a rice cooker body 51. An inner pan 53 that is detachably mounted is provided. The rice cooker main body 51 includes an inner case 55 having a shape substantially similar to the inner pot 53 inside a bottomed cylindrical outer case 54 as an outer body, and is adjacent to a bottom wall 55a of the inner case 55 from below. In position, the bottom coil 56 for electromagnetic induction heating,
Further, first side coils 57 are provided so as to surround the bottom side of the curved wall 55b on the outer peripheral side. In recent years, the second side coil 58 has been provided at an appropriate interval above the first side coil 57.

The bottom coil 56 is formed by spirally winding a coil material such as a copper pipe, for example, so as to form a donut-shaped flat plate as a whole. On the other hand, the first side coil 57 and the second side coil 58 surrounding the peripheral wall of the inner case 55, that is, the above-mentioned curved wall 55b and the cylindrical wall 55c above the curved wall 55b are formed by spirally winding the coil material. Wrap it,
Each is formed in the shape of a conical coil or a cylindrical coil having a predetermined coil length in the vertical direction.

In the illustrated example, the first side coil 57 has 10 turns and the second side coil 58 has 7 turns.
To the extent, each is formed by close winding. In such a shape, if each of the winding portions corresponding to one turn is called a winding coil portion, each of the winding coil portions is formed in a substantially horizontal straight line over the whole in side view. 2 side coil 57.5
The vertical width dimension of 8, ie, the coil length, substantially matches the dimension obtained by multiplying the outer diameter of the coil material by the number of turns.

When the inner pot 53 is mounted in the inner case 55 and the coils 56 to 58 are energized, these coils 56 to 58
The bottom wall 55a and the peripheral wall 55b
An eddy current is generated in each of 55c and heat is generated, whereby the rice and water contained in inner pot 53 are heated, and the rice is cooked.

[0006] By the way, the so-called "furnace cooking" is ideal for rice heating. After the water supply step of supplying water to rice at the beginning, the heating power is increased toward the bottom and the wall is wider from the bottom wall to the surrounding wall. By heating over a range and cooking rice at once, more delicious rice is cooked. For this reason, in the above, the second side coil 58 is further provided above the bottom side coils 56 and 57 so as to heat the inner pot 53 over a wider range.

[0007]

However, in the conventional rice cooker having the second side coil 58 provided above the bottom coils 56 and 57 in addition to the bottom coils 56 and 57 as described above, for example, The area between the first side coil 57 and the second side coil 58 tends to have a lower temperature than the areas facing the coils 57 and 58.

That is, the inner pot 53 of such an IH type rice cooker is formed by using, for example, a clad material of stainless steel and aluminum, and self-heat is generated by the eddy current in the stainless steel layer portion, and the temperature rises. In this case, since stainless steel is a material having a relatively small thermal conductivity, the amount of heat applied to each of the first and second side coils 57 and 58 in the height regions corresponding to the respective width dimensions is equal to that of each coil 57.5
8 is not immediately transmitted to the area between the coils 57 and 58,
The rice heating operation is performed in a state where a relatively large temperature difference has occurred between the region 58 and the region 58.

In such a heating state, the internal convection generated during the heating is different from that in the case of the above-mentioned cooking of the furnace, and thus, for example, the amount of stored rice is changed. In such a case, the cooked rice becomes uneven, and there is a problem that it is difficult to stably obtain uniform and delicious rice over the whole.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a rice cooker capable of generating a high-quality rice by generating a heating state close to that of a cooking furnace. It is in.

[0011]

SUMMARY OF THE INVENTION Therefore, claim 1 of the present invention is provided.
The rice cooker is provided with a bottom coil facing the bottom wall of the inner pot and a side coil surrounding the peripheral wall of the inner pot, in the rice cooker main body in which the inner pot containing rice and water is mounted, A rice cooker formed so as to conduct electromagnetic induction heating of an inner pot by energizing these coils, wherein the side coil has a bent portion bent upward or downward along the peripheral wall of the inner pot. It is characterized by being formed in.

According to this configuration, for example, in a region of the side coil bent upward, a region having a higher height is heated, and in a region bent downward,
The lower area is heated. Therefore, the overall heating width in the vertical direction is increased. As a result, by using this side coil instead of, for example, the second side coil 58 described with reference to FIG. 6, the height position on the upper side of the heating region is made substantially the same as in the related art. Can be heated to lower areas. Thereby, it becomes possible to reduce the temperature unevenness such that the temperature between the first side coil 57 and the second side coil 58 in the related art becomes low.
You can cook better quality rice.

In the rice cooker according to a second aspect, in the rice cooker according to the first aspect, the side coil is formed in a wave shape in which an upwardly convex bent portion and a downwardly concave bent portion are alternately connected in the circumferential direction. It is characterized by having.

According to this configuration, the rice heating operation can be performed in a heating state close to the cooking of the furnace. In other words, in the furnace cooking, the flame that rises along the side wall from the bottom wall of the kettle does not uniformly surround the kettle in the circumferential direction on the top end side, but has a shape that is appropriately divided in the circumferential direction. Then, the wall surface of the pot is heated. Heating similar to the shape of the flame tip is performed by the corrugated side coil as described above. In this case, in the heating area by the side coil, a temperature difference occurs in the circumferential direction at the same height position. For this reason, the rice and water in the inner pot not only convect in the vertical direction, but also the convection in the circumferential direction caused by the temperature difference, and thus the rice and water in the inner pot. And the temperature rises while being further suitably stirred. As a result, it is possible to cook high-quality rice that is evenly cooked over the entire inner pot.

According to a third aspect of the present invention, in the rice cooker according to the second aspect, the outer peripheral side of the bottom portion of the inner pot is formed to have a curved cross section, and the circumferential interval of the downwardly concave bent portion of the side coil is adjusted. It is characterized in that the side coil is arranged so as to surround the bottom outer peripheral side of the inner pan, with the interval being smaller than the circumferential interval of the upwardly convex bent portion.

According to this configuration, in the side coil, the circumferential interval of the downwardly concave bent portion is smaller than the circumferential interval of the upwardly convex bent portion. The shape is denser on the side. Therefore, the heating power per unit area applied to the inner pan by energizing the side coil is larger on the lower side, and the inner pan is heated with stronger thermal power. In this way, with one side coil, it is possible to perform heating in a state closer to cooking with a furnace, that is, heating with stronger heating power toward the bottom side, thereby simplifying the entire configuration and improving quality. You can cook rice.

The rice cooker according to claim 4 is the rice cooker according to claim 1, 2, or 3.
In the rice cooker described above, the vertical interval of the circulating coil portion corresponding to each turn of the side coil is formed such that the lower side is smaller than the upper side.

According to such a configuration, the degree of density of the coil is formed to be higher at the lower side. Therefore, similarly to the above, heating is performed with one side coil having a higher thermal power at the bottom side. Therefore, it is possible to cook high-quality rice with a simpler overall configuration.

A rice cooker according to a fifth aspect of the present invention is the rice cooker according to any one of the first to fourth aspects, wherein the bottom side coil is smaller in diameter than the coil material used for the upper side coil. It is characterized by being formed using

According to this configuration, even when the side coil is formed by, for example, close winding, the number of turns per unit width in the vertical direction can be increased on the bottom side. Therefore, even with such a configuration, it is possible to perform heating with higher heating power toward the bottom side, and it is possible to cook high-quality rice.

[0021]

[Embodiment 1] Next, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 2, the rice cooker according to the present embodiment includes a rice cooker main body 1 and a lid 2 attached to an upper portion of the rice cooker main body 1.
And an inner pot 3 detachably mounted in a downwardly recessed space formed substantially at the center of the rice cooker main body 1.

The rice cooker main body 1 has a bottomed cylindrical outer case 4 as an exterior body, an inner case 5 surrounding the recessed space, and the upper ends of these cases 4.5 connected to each other. The shoulder case 6 provided is provided.

Inner pan 3 mounted from above in inner case 5
Is formed in a round pot shape with a large opening at the upper end by using, for example, a two-layer clad material in which the outer layer is made of stainless steel and the inner layer is made of aluminum, or a three-layer clad material in which a copper plate is interposed. That is, a portion from the upper end to a position slightly lower than the intermediate height position in the vertical direction is formed as a cylindrical body 3a, and between the body 3a and the bottom wall 3b that spreads substantially horizontally on the bottom side. A curved portion 3c having a relatively large curvature is provided, and the lower end of the body portion 3a and the periphery of the bottom wall 3b are connected to the curved portion 3c.
It is formed in a shape that continues smoothly through c.

A flange 3e, which extends slightly radially outward from the outer peripheral surface of the body 3a, is provided on the upper end side of the body 3a via a narrowed portion 3d slightly curved inward in the radial direction. Further provided. On the other hand, the bottom wall 3b has a bottom wall central convex portion 3f having a slightly upwardly convex shape in the central region thereof.
Is provided.

The inner case 5 is formed in a shape substantially following the outer shape from the position of the continuous portion of the narrowed portion 3d and the body 3a in the inner pot 3 having the above-mentioned shape. That is,
The inner pot 3 has a body portion 5a, a curved portion 5b, a bottom wall portion 5c, and a bottom wall center convex portion 5d having shapes corresponding to the body portion 3a, the curved portion 3c, the bottom wall 3b, and the bottom wall central convex portion 3f, respectively. It is formed in a bottom cylindrical shape.

A space surrounded by the inner case 5 and the outer case 4 and the shoulder case 6 is formed as a device installation space 7. The space 7 has a center sensor at a position on the center line of the inner case 5. A unit 8 is arranged. The unit 8 has a built-in temperature sensor 9 made of a thermistor or the like in a sensor mounting portion 8a that projects upward through a central through hole in the central convex portion 5d of the bottom wall of the inner case 5. The sensor mounting portion 8a is configured to be vertically movable, and is urged by a spring so as to be located at its upper limit position.

When the inner pot 3 is mounted, the sensor mounting portion 8a is slightly pushed down by the inner pot 3, so that the temperature sensor 9 is attached to the bottom convex portion 3f of the bottom wall of the inner pot 3. And the temperature of the inner pot 3, that is, the temperature of the rice and water stored in the inner pot 3 during the rice heating operation and the warming operation described later, and the temperature of the cooked rice, Is detected.

Then, three electromagnetic induction coils (hereinafter, simply referred to as coils) 11 to 13 are arranged along the bottom wall portion 5c and the curved portion 5b of the inner case 5. The first coil 11 is formed in a spiral shape surrounding the center sensor unit 8, and is provided so as to be entirely adjacent to the lower surface along the bottom wall 5 c of the inner case 5. Note that a double cylindrical wall 5e that extends through the center hole of the first coil 11 and extends slightly below is formed integrally with the continuous region between the bottom wall 5c of the inner case 5 and the bottom wall central protrusion 5d, The center sensor unit 8 is partitioned from the first coil 11 and assembled in the cylindrical wall 5e.

The second coil 12 is connected to the curved portion 5 of the inner case 5.
3b, and the third coil 13 is provided along the upper side of the curved portion 5b. The overall shapes of the second and third coils 12 and 13 will be described later in detail.

Further, on the outer periphery of the body 5a of the inner case 5 above the third coil 13, a heat insulation heater 14 composed of a resistance heating type electric heater is further wound. Is wrapped around. Also, on the inner peripheral side of the upper end of the shoulder case 6, the flange 3e of the inner pot 3 is provided.
The shoulder heater 16 for heating a radiator plate 33 described later to prevent dew condensation on the radiator plate 33 at a height position corresponding to
Is provided.

On the other hand, the front side (left side in the figure) of the outer case 4 is formed so as to bulge forward, and the curved front wall 6a of the shoulder case 6 forms an outer case on the front upper side of the rice cooker main body 1. A case is formed. An operation display section is provided at the center of the front wall 6a. That is, the liquid crystal panel 17 is disposed obliquely inside the operation display section.
A control circuit board 18 on which a microcomputer or the like having a function as an operation control device is mounted is provided.
A plurality of operation keys (only one is shown) 19 such as a rice cook start key, a rice cook menu selection key, a warming key, and a reserved rice cook setting key which are pressed down from the front side are provided on the substrate 18.
Are mounted side by side around the liquid crystal panel 17.
In accordance with the operation with these operation keys 19, the energization and the like to the above-described coils 11 to 13, the heat retaining heater 14, and the shoulder heater 16 are controlled by the microcomputer described above.
A rice-cooking operation and a warming operation described below are performed.

The power supply circuit board 21 is further arranged inside the control circuit board 18 in the above-described device arrangement space 7. Circuit components and the like for supplying electric power to the coils 11 to 13 are mounted on the substrate 21.
Further, a heat sink 23 having a cooling fan 22 is attached to the substrate 21, and a heat generating component such as a power transistor among the circuit components is mounted on the heat sink 23 to prevent overheating thereof. I have.

On the other hand, a blower fan 24 composed of a centrifugal fan is installed on the rear side in the rice cooker main body 1. The cooling air generated by operating the blower fan 24 is supplied in a circumferential direction through an annular passage 25 formed between the upper end of the inner case 5 and the shoulder case 6, and further supplied to the inner wall 6 b of the shoulder case 6. It is supplied to the inside of the inner wall 6b through a plurality of openings (not shown) formed. Thereby, the cooling air enters between the inner pot 3 and the inner case 5, and the inner pot 3 is cooled. This blower fan 24
Is operated after the rice is cooked in the inner pot 3, whereby the cooked rice is cooled from 100 ° C. to, for example, 72 ° C.
The temperature drops quickly to the set temperature of about ℃,
The deterioration of the rice, which tends to occur in this temperature range, is minimized, and the operation is shifted to the warming operation.

The lid 2 is formed by providing an outer lid 31 made of synthetic resin as an upper surface exterior body. This outer lid 31
A pressure regulating valve unit 32 having a steam passage vertically penetrating the lid 2 is provided substantially at the center of the pressure regulating valve unit 32. The steam generated in the inner pan 3 is released to the outside through the pressure regulating valve unit 32, so that the inside is maintained at a predetermined pressure or less. At the lower end side of the pressure regulating valve unit 32, a thin metal plate-shaped heat radiating plate 33 and an inner lid 34 extending radially outward are attached. When the lid 2 is closed, the heat radiating plate 33 is formed so that its outer peripheral side extends outward beyond the upper end edge of the inner pot 3, and its outer end contacts the shoulder heater 16 from above. Has become. Thus, the entire heat radiating plate 33 is heated by energizing the shoulder heater 16.

The space between the outer lid 31 and the radiator plate 33 is
Vacuum insulated lid 3 having closed space Sv evacuated inside
5 are installed. With such a heat insulating lid 35,
The amount of heat radiated upward from the inside of the container body 1 is suppressed as small as possible, thereby making it possible to more efficiently perform the rice heating operation and the heat keeping operation described later.

The lid 2 having the above configuration is attached to the rear end side (right end side in the figure) of the shoulder case 6 by a hinge pin 36 so as to be rotatable around the hinge pin 36. On the other hand, a lock mechanism 37 for locking the lid 2 to the rice cooker main body 1 is provided on the front end side of the lid 2 at a closed position (position shown) covering the upper surface opening of the inner pot 3.

Next, the first to third coils 11 to 1
The detailed shape of No. 3 will be described with reference to FIG. These coils 11 to 13 are each manufactured using, for example, a copper pipe having a predetermined diameter as a coil material. As described above, the first coil (bottom coil) 11 is formed by winding a coil material in close contact with the coil material so as to form a flat plate as a whole. Therefore, the first coil 11 has a thickness in the vertical direction equal to the outer diameter of the coil material, and is formed in a donut-shaped disk as a whole.

The first coil 11 is provided at a position adjacent to the lower side along the bottom wall 5c of the inner case 5. The first coil 11 is formed to have, for example, about 11 turns. In the following, the circling part corresponding to each winding is referred to as the circulating coil part
This will be described.

The first coil 1 arranged as described above
1 is that the outermost circumferential coil portion 11a is located slightly inside the continuous portion between the bottom wall 5c and the curved portion 5b in the inner case 5, and the innermost circumferential coil portion 11b
Are formed in such a manner that the inner and outer diameters of the inner case 5 are located substantially opposite to the continuous portion of the bottom wall portion 5c and the bottom wall center convex portion 5d from below. Thereby, the first coil 1
With the energization of 1, the eddy current is generated in the bottom wall 3b of the inner pot 3, and the bottom wall 3b is heated.

The second coil 12 is formed by spirally winding a coil material in close contact. More specifically, the inner diameter of each orbiting coil portion 12a is gradually increased from bottom to top, so that the inner surface of the coil follows the curved shape on the lower side of the curved portion 5b of the inner case 5. It is formed as follows. And each orbiting coil part 1
Are formed linearly in a side view along a substantially horizontal plane (strictly speaking, a slight inclined surface which is vertically displaced by the outer diameter of the coil material at the center point target position).

Therefore, the vertical width W1 of the second coil 12 is substantially equal to the outer diameter of the coil material multiplied by the number of turns (10 turns in the present embodiment). When the second coil 12 is energized, in the inner pot 3, eddy current is generated almost uniformly over the entire circumference in the lower region of the curved portion 3 c along such a coil shape and heated.

On the other hand, the third coil 13 is formed by tightly winding the coil material in a substantially spiral manner, and is provided with a coil portion 13a.
.. Is similar to the second coil 12 in that the inner diameter of each of the coils is formed so as to increase slightly from bottom to top, but the third coil 13 further has a wavy shape in a side view. In addition, a bent portion (hereinafter, referred to as a convex bent portion) Bu that bends upwardly convexly along the peripheral wall of the inner case 5 and a bent portion (hereinafter, referred to as a concavely bent portion) Bd that is bent downwardly concavely extend in the circumferential direction. Are formed in such a shape that they are alternately connected. In the present embodiment, the third coil 13 is formed in a shape in which four convex bending portions Bu and four concave bending portions Bd are provided at substantially equal intervals in the circumferential direction.

The third coil 13 is provided in a height region extending from the upper side of the curved portion 5b of the inner case 5 to the lower side of the body 5a. The width of the third coil 13
W2 is a dimension obtained by multiplying the outer diameter of the coil material by the number of turns (seven turns in the case of the present embodiment). A region Hw sandwiched vertically between the top height position and the bottom height position of the concave bending portion Bd is a heating region, and the inner pot 3
In the region Hw, an eddy current is generated in a waveform region along the shape of the third coil 13 in the region Hw, and the region is heated.

In the rice cooker having the above-described configuration, when the inner pot 3 containing rice and water is set in the rice cooker main body 1, the rice heating operation is energized to each of the coils 11 to 13, and accordingly, The heating is performed by raising the temperature of the inner pan 3 and heating the rice and water. That is, during the rice heating operation, first, the first coil 11 is energized to heat the bottom wall 3b of the inner pot 3 as described above.
The bottom-side region of the curved portion 3c of the inner pot 3 is heated by energizing the inner pan 3. As a result, the temperature of the rice and water in the inner pot 3 rises from the bottom side, whereby convection occurs, and the overall temperature rises.

At this time, the third coil 13 is also energized at the same time, but the third coil 13 surrounding the upper region of the curved portion 3c in the inner pot 3 is formed in a wave shape as described above, and Since the width of the heating area Hw in the vertical direction is widened, the inner pot 3
Is heated over a wider range over the entire width of the heating region Hw. As a result, the entire inner pan 3 is further reduced in a state where the temperature unevenness such that the temperature in the region between the second coil 12 and the third coil 13 as the side coils surrounding the peripheral wall of the inner pan 3 becomes low is minimized. The temperature can be raised quickly.

Further, since the third coil 13 has a corrugated shape as described above, the heating state becomes closer to "furnace cooking". In other words, in the furnace cooking, the flame that rises along the side wall from the bottom wall of the kettle does not uniformly surround the kettle in the circumferential direction on the top end side, but has a shape that is appropriately divided in the circumferential direction. Then, the peripheral wall of the pot is heated.
The heating similar to the shape of the tip of the flame is performed by the third coil 13.
It is done by.

In this case, at the same height position, a region where the third coil 13 is heated while facing the third coil 13 and a region where the third coil 13 is not heated alternately occur in the circumferential direction.
Heating that causes an appropriate temperature difference in the circumferential direction is also performed. As a result, the rice and water in the inner pot 3
In addition to simply convection in the vertical direction, circumferential convection due to the temperature difference is added to this,
The temperature rises while the rice and water in the inner pot 3 are more appropriately stirred. As a result, it is possible to cook high-quality rice without uneven cooking over the entire inside of the inner pot 3.

As described above, the energization of each of the coils 11 to 13 is continued, and after the entire temperature rises to a boiling state,
Further, when water is lost and the cooked state is reached, a sharp rise in temperature from the boiling temperature occurs. When such a temperature change is detected, energization of each of the coils 11 to 13 is controlled so as to lower the temperature of the inner pan 3 to the boiling temperature.
Thereafter, the cooked rice is steamed by maintaining this state for a predetermined time.

When the cooking of the rice is completed, the operation automatically shifts to the warming operation. In this heat retention operation, first, the power supply to the coils 11 to 13 is stopped, the power supply to the shoulder heater 14 is started, and the blown fan 24 is operated to keep the cooked rice at a predetermined temperature of, for example, about 72 ° C. Decrease quickly to temperature. Thereafter, control is performed to start energization of the heat retaining heater 14 and maintain the rice at the above-described heat retaining temperature. In addition, even during the heat retention operation, the energization of the coils 11 to 13 is controlled as needed.

As described above, in the rice cooker according to the present embodiment, the third coil 13 surrounding the peripheral wall of the inner pot 3 is formed in a wavy shape having bent portions Bu and Bd bent up and down. As a result, since the overall heating width in the vertical direction is increased, the temperature of the region between the second coil 12 and
Temperature unevenness such that the temperature becomes lower than the areas facing the second and third coils 12 and 13 is reduced, and rice of higher quality can be cooked.

In particular, since the third coil 13 is formed in a wave shape over the entire circumference, a heating state similar to the shape of the tip of a flame in the cooking of a furnace is generated. As a result, in addition to the vertical convection, the circumferential convection is also added to the rice and water in the inner pot 3 in a complicated manner. It is possible to cook.

[Embodiment 2] Next, another embodiment of the present invention will be described. The rice cooker of the present embodiment is the same as that of FIG.
The rice cooker according to the first embodiment described with reference to FIG. 2 does not include the third coil 13 and uses the second coil 12 as shown in FIG.
In that it is formed in the shape shown in FIG. The other configuration is almost the same as that of the first embodiment. Therefore, members having the same functions as those shown in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. The same applies to other embodiments described later.

The second coil 12 in the present embodiment
Is formed, for example, by close winding with the number of turns being about 10,
In substantially the same manner as in the third coil 13, a convex bent portion Bu and a concave bent portion Bd are formed in a wavy shape alternately continuous in the circumferential direction. The second coil 12 is formed by increasing the overall dimension Hd in the up-down direction, and the top of the convex bending portion Bu is located at a location where the trunk 3a and the bending portion 3c of the inner pan 3 are connected. While located at the corresponding height, the bottom of the concave bent portion Bd is formed in a shape located at a height corresponding to the bottom wall 3 b of the inner pot 3.

Further, the second coil 12 is formed so that the whole thereof follows the substantially entire shape of the curved portion 5b of the inner case 5.
It is formed in a so-called aperture shape in which the diameter of a circle inscribed in a horizontal plane at an arbitrary height is gradually reduced downward. The second coil 12 is, for example,
The convex bending portion Bu and the concave bending portion Bd are each formed in a shape in which eight pieces are provided at substantially equal intervals in the circumferential direction, and by forming the above-described drawing shape, the circumferential direction of the concave bending portion Bd is formed. Is smaller than the circumferential interval of the convex bending portion Bu, that is, the shape is such that the degree of density in the circumferential direction becomes lower toward the lower side.

The second coil 12 and the first coil (bottom coil) 11 provided in the same manner as in the first embodiment are energized to perform the rice cooking heating operation. At this time, the heating of the peripheral wall of the inner pot 3 by the second coil 12 is also in a state close to the shape of the flame in the cooking of the stove similarly to the above. Further, according to the second coil 12, since the degree of density in the circumferential direction is higher at the lower side, the heating power per unit area applied to the inner pot 3 is higher at the lower side, and is stronger. The inner pot 3 will be heated by thermal power.

As described above, in the present embodiment, one side coil 12 secures a heating area covering substantially the same area as the second and third coils 11 and 12 in the first embodiment. In the first embodiment, the second and third coils 1
While a non-heated area is formed over the entire circumference between 1 and 12, in the present embodiment, there is no such non-heated area, so that uneven heating is further suppressed. In addition, as described above, heating with a higher heating power is performed closer to the bottom side, so that a heating state closer to cooking with a furnace can be obtained, so that the overall configuration is simplified, and rice of higher quality is further improved. Can be cooked.

[Embodiment 3] Next, still another embodiment of the present invention will be described with reference to FIG. In the rice cooker of the present embodiment, a second coil 12 formed substantially in the same manner as in the second embodiment is provided. That is,
Similarly to the above, the second coil 12 is formed in a throttle shape having a smaller coil diameter toward the lower side, and is formed so that the degree of density in the circumferential direction becomes lower toward the lower side. Further, in the second coil 12, for example, the circulating coil portions corresponding to the lower three windings are formed by close-contact winding, while above the circulating coil portions, the interval between the vertically circulating coil portions adjacent to each other is It is formed in a shape that gradually spreads upward.

Therefore, the second coil 12 has a shape in which a difference in density is generated in the vertical direction as well as in the circumferential direction. For this reason, with one side coil 12, the heating power is further concentrated on the bottom side, and the heating can be performed over a wider range Hd in the vertical direction.

As described above, the convection in the inner pot 3 is further promoted by concentrating the heating power on the bottom side, and the rice is cooked at a stretch in a short time because it is heated over a wider range in the vertical direction. It is possible to cook even better quality rice.

[Fourth Embodiment] FIG. 5 shows a main part configuration of a rice cooker according to still another embodiment of the present invention. In this rice cooker, similarly to the first embodiment, the second coil 12 provided to surround the bottom side of the curved portion 5b of the inner case 5 and the second coil 12 provided to surround the upper side of the curved portion 5b. A third coil 13 is provided, and
Both of the coils 12 and 13 are formed so as to have a wave shape in a side view.

Although the coils 12 and 13 are formed by close-contact winding, respectively, the second coil 12 on the bottom side is formed.
Is formed using a coil material having a diameter (hereinafter, also referred to as a coil wire diameter) smaller than that of the third coil 13, whereby the second coil 12 has a winding number per unit width of the third coil 13. More than thirteen.

As described above, even with a configuration in which the coil wire diameters are different between the bottom side and the top side and the number of turns per unit width is increased on the bottom side, it is possible to perform heating in which the heating power is concentrated on the bottom side. And the second and third coils 12 and 13
Are formed in a waveform, so that these coils 12
-The non-heating area between the 13 can be reduced as much as possible, and heating can be performed over a wider range in the vertical direction. Therefore, even with such a configuration, high-quality rice can be cooked.

Although the specific embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various changes can be made within the scope of the present invention. For example, in the third embodiment described with reference to FIG. 4, in addition to the configuration in which the degree of density is different in the circumferential direction by making the whole a drawn shape, the density in the vertical direction is also changed by making the upper and lower intervals of the orbiting coil part different. Although the side coil 12 having a difference between them is described as an example, the configuration in which the interval between the circulating coil portions is made different to produce a difference in density in the vertical direction is shown in FIGS. 1 and 5 alone. It is also possible to apply the present invention to a coil that does not have a special drawn shape, such as the third coil 13.

The fourth embodiment described with reference to FIG.
In the above, an example in which the second coil 12 and the third coil 13 are formed using coil materials having different diameters from each other has been described. As a configuration using such coil materials having different diameters, for example, FIG. In the second coil 12 having 10 turns,
It is also possible to divide this into five windings on the lower side and five windings on the upper side, and to form a structure in which the lower five windings are made of a small-diameter coil material and the upper five windings are made of a large-diameter coil material. is there. In this case, even if the diameter of the coil material is different in the middle, the coil material is manufactured as a coil having a tightly wound structure as a whole.

On the other hand, in order to further increase the heating power on the bottom side, for example, a coil similar to the second coil 12 shown in FIG. 1 may be surrounded from the outside on the bottom side of the second coil 12 in FIG. Therefore, it is also possible to form a double coil structure on the bottom side.

In each of the above embodiments, the side coil 1
Although the shape of the top of 2 ・ 13 is such that the position of the top most coincides with the height of the continuous portion of the body portion 3a and the curved portion 3c of the inner pot 3, the size in the vertical direction is further increased. Shape, for example, the top of the convex bent portion Bu is full water level (for example, when the cooking capacity is 5 go, if you put 5 go rice in the inner pot and pour water corresponding to this (A water surface position).

Further, in each of the above embodiments, the second coil and the third coil 13 are formed in a wave shape in which the convex bent portions Bu and the concave bent portions Bd are alternately and continuously connected. For example, a shape in which a portion along a substantially horizontal direction is provided between both bent portions Bu and Bd, or a shape in which only a bent portion having an upward convex shape is provided for such a horizontal portion, or It is also possible to adopt a shape having only a lower concave bent portion or the like. Also, in the above description, a diagram is shown in which each of the bent portions Bu and Bd is bent substantially in an arc shape, but, for example, when the coil wire diameter is small and the number of turns is small, etc.
It is also possible to adopt a configuration or the like bent into a square shape.

[0068]

As described above, in the rice cooker according to the first aspect of the present invention, the side coil having the bent portion bent upward and downward along the peripheral wall of the inner pot is provided.
The peripheral wall of the inner pot is heated over a wider range. As a result, for example, uneven heating between a plurality of side coils, which has conventionally occurred, can be reduced, and thereby, high-quality rice can be cooked.

In the rice cooker according to the second aspect, since the side coil is formed in a wave shape, it is possible to further perform heating similar to the shape of the tip of the flame in the cooking of the furnace, thereby making it possible to heat the inner pot. In addition to the vertical convection as well as the circumferential convection to the rice and water, the rice cooking is heated while being suitably stirred. As a result, it is possible to cook high-quality rice that is evenly cooked throughout.

In the rice cooker according to the third aspect, the circumferential interval of the lower concave bent portion of the side coil is made smaller than the circumferential interval of the upper convex bent portion, and the side coil is formed inside. It is formed so as to follow the curved shape on the outer peripheral side of the bottom of the pot. In this case, the degree of the density in the circumferential direction becomes lower toward the lower side, and therefore, by energizing this side coil, heating can be performed with one side coil having a higher thermal power toward the bottom side. This makes it possible to cook even better quality rice by making the overall configuration simpler.

In the rice cooker according to the fourth aspect, the vertical space between the circulating coil portions corresponding to each turn of the side coil is formed so that the lower side is smaller than the upper side. In the same manner as described above, it is possible to perform heating with a higher thermal power at the bottom side with one side coil. Therefore, this also makes it possible to cook high-quality rice with a simpler overall configuration.

In the rice cooker according to the fifth aspect, the side coil on the bottom side is formed by using a coil material having a smaller diameter than the coil material used on the upper side. Even when the partial coil is formed, the number of turns per unit width in the vertical direction on the bottom side can be increased. Therefore, even with such a configuration, it is possible to perform heating with higher heating power toward the bottom side, and it is possible to cook high-quality rice.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view showing an inner pot, an inner case, and an electromagnetic induction coil of a rice cooker according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing the overall configuration of the rice cooker.

FIG. 3 is a partially cutaway front view showing an inner pot, an inner case, and an electromagnetic induction coil of a rice cooker according to another embodiment of the present invention.

FIG. 4 is a partially cutaway front view showing an inner pot, an inner case, and an electromagnetic induction coil of a rice cooker according to still another embodiment of the present invention.

FIG. 5 is a partially cutaway front view showing an inner pot, an inner case, and an electromagnetic induction coil of a rice cooker according to still another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a configuration of a conventional rice cooker.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rice cooker main body 3 Inner pan 3a Body part (peripheral wall) 3b Bottom wall 3c Curved part (peripheral wall) 11 First coil (bottom coil) 12 Second coil (side coil) 13 Third coil (side coil) Bu convex Bend Bd Concave Bend

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3K051 AA08 AB04 AB05 AC33 AD05 AD15 AD37 CD42 CD43 CD45 4B055 AA07 BA22 BA28 BA63 BA66 CA05 CA71 CB02 CB03 CC03 CC04 CC17 CD04 DA03 DB14 FB02 FB05 GA04 GA13 GB05 GC06 GC31

Claims (5)

[Claims] 1. A rice cooker body in which an inner pot containing rice and water is mounted, a bottom coil facing a bottom wall of the inner pot, and a side coil surrounding a peripheral wall of the inner pot, provided. It is a rice cooker formed so as to energize these coils to heat the inner pot by electromagnetic induction heating, wherein the side coil has a bent portion bent upward or downward along the peripheral wall of the inner pot. A rice cooker characterized by being formed in a rice cooker. 2. The rice cooker according to claim 1, wherein the side coil is formed in a wave shape in which an upwardly convex bent portion and a downwardly concave bent portion are alternately connected in a circumferential direction. 3. The outer peripheral side of the bottom portion of the inner pot is formed to have a curved cross section, and the circumferential interval of the lower concave bent portion of the side coil is smaller than the circumferential interval of the upper convex bent portion. The rice cooker according to claim 2, wherein the side coil is disposed so as to surround the outer peripheral side of the bottom of the inner pot. 4. The vertical coil according to claim 1, wherein the vertical coil interval of the circulating coil portion corresponding to each turn of the side coil is formed to be smaller on the lower side than on the upper side. Or 3 rice cookers. 5. The method according to claim 1, wherein the bottom side coil is formed using a coil material having a smaller diameter than the coil material used for the top side coil. Kano rice cooker.