JP7179686B2 - heating cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating cooker for heating a container having a horizontally long bottom.

2. Description of the Related Art Conventionally, in a heating cooker such as an electric rice cooker, it is known that the shape of a container for storing an object to be heated is oblong, such as an ellipse in plan view. For example, in Patent Document 1, by making the shape of the pot of an electric rice cooker in plan view oblong, such as elliptical or rectangular, it is possible to reduce the size of the lid that is connected to the main body and covers the top of the pot. Proposed. In the electric rice cooker of Patent Literature 1, by making the lid smaller, the overall height when the lid is opened can be reduced, and the storability is improved.

JP-A-2002-65454

As described in Patent Document 1, when the shape of the bottom of the container is oblong, for example, it becomes possible to stew a whole fish or boil pasta without folding, which improves usability. However, in the electric rice cooker of Patent Document 1, since the oblong container is heated by the circular electromagnetic coil, the heating efficiency is poor and uneven heating is likely to occur. Further, in Patent Document 1, in order to uniformly heat a horizontally long container, it is proposed to make only the bottom of the container circular, but in this case the advantage of the horizontally long shape is lost.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems, and to provide a cooking device capable of suppressing uneven heating of a container having a horizontally long bottom.

A heating cooker according to the present invention includes a container having a horizontally long bottom, a main body that houses the container, a horizontally long heating unit that heats the container, and a plurality of magnetic bodies arranged below the heating unit. , the heating unit is arranged so that the outer region of the bottom of the container is heated more strongly than the inner region, the outer region being the region outside the middle from the center to the periphery of the bottom, The inner region is a region inside the middle from the center to the outer periphery of the bottom , the heating part is a heating coil that induction-heats the container, and the plurality of magnetic bodies has a longer axis than the short axis of the bottom. The long axis region is centered at the center of the bottom, and when the long axis of the bottom is 0 °, it is a region of ± 45 ° from the long axis, and the short axis region is the long axis It is an area other than the area .

According to the heating cooker of the present invention, by arranging the heating part so that the outer region of the bottom of the container is heated more strongly than the inner region, even when the bottom is horizontally long, Heat concentration can be alleviated, and uneven heating of the container can be suppressed.

1 is an external perspective view of a heating cooker according to Embodiment 1. FIG. 1 is a schematic cross-sectional view of a heating cooker according to Embodiment 1. FIG. 3 is a control block diagram of the heating cooker of Embodiment 1. FIG. FIG. 7 is a diagram showing the relationship between the distance from the center and the temperature of the container when the container is heated by the heating unit in the prior art. It is a figure explaining the distance from the center of the container in FIG. It is a figure explaining the spread of the heat in the bottom part of the container in a prior art. 4A and 4B are diagrams illustrating an outer region and an inner region of the bottom of the container according to Embodiment 1; FIG. 4 is a diagram illustrating the bottom of the container according to Embodiment 1. FIG. FIG. 4 is a diagram for explaining the arrangement of heating units according to Embodiment 1; FIG. 4 is a diagram illustrating a long-axis region and a short-axis region of the bottom of the container according to Embodiment 1; FIG. 10 is a diagram illustrating the arrangement of heating units in a modification of Embodiment 1; 4 is a diagram showing temperature changes at the bottom of the container in Embodiment 1. FIG. FIG. 10 is a diagram for explaining the arrangement of heating units according to Embodiment 2; FIG. 10 is a diagram illustrating the arrangement of heating units in a modification of the second embodiment; FIG. 11 is a diagram for explaining the arrangement of heating units according to Embodiment 3; FIG. 11 is a diagram illustrating the arrangement of heating units in Modification 1 of Embodiment 3; FIG. 11 is a diagram for explaining the arrangement of heating units in Modification 2 of Embodiment 3; FIG. 4 is a diagram illustrating an outer region and an inner region when the container has a rectangular bottom;

Hereinafter, embodiments of the heating cooker will be described with reference to the drawings. In addition, the relation of the size of each constituent member in the drawing may differ from the actual one. In addition, in the following drawings including FIG. 1, the same reference numerals are the same or equivalent, and this is common throughout the specification.

Embodiment 1.
FIG. 1 is an external perspective view of a heating cooker 100 according to Embodiment 1. FIG. FIG. 1 shows a state in which an outer lid 11 attached to the main body 1 is opened to expose the top opening of the container 7 . FIG. 2 is a schematic cross-sectional view of the heating cooker 100 of Embodiment 1. FIG. As shown in FIGS. 1 and 2, the heating cooker 100 of Embodiment 1 includes a main body 1 having a cylindrical shape with a bottom, a container housing portion 2 fixed to the inside of the main body 1, and a container housing portion 2. and a pot-shaped container 7 detachably stored in the container. The heating cooker 100 also includes an inner lid 9 which is a lid body that closes the top opening of the container 7, and an outer lid 11 that is engaged with the main body 1 so as to be openable and closable and is connected to the inner lid 9 to cover the inner lid 9. and Main body 1 and outer lid 11 constitute an outer shell of cooking device 100 .

The container storage part 2 is formed in a cylindrical shape with a bottom, and the container 7 is detachably stored therein. The container 7 has a cylindrical shape with a bottom and is made of a material containing a magnetic metal that generates heat by induction heating. Inside the container 7, water or foodstuffs, which are objects to be heated, are accommodated. Further, the container 7 of the present embodiment has a laterally long bottom portion 7b in plan view. More specifically, the bottom portion 7b of the container 7 has an elliptical shape in plan view.

A gripping portion 8 protruding outward from the side surface of the container 7 is provided at the longitudinal end of the container 7 . The container 7 is held in the main body 1 by placing the grip portion 8 on the container storage portion 2 . A flange portion 7a extending outward is formed around the top opening of the container 7. As shown in FIG. A lid packing 10, which is a seal, is provided on the peripheral edge of the inner lid 9, and the lid packing 10 ensures sealing between the flange portion 7a of the container 7 and the inner wall surface of the container 7 and the inner lid 9. .

The long axis side of the flange portion 7a may be formed larger than the short axis to form the grip portion 8. As shown in FIG. When the container 7 has an elliptical shape, the inner lid 9 is more likely to shift in the long axis direction than in the short axis direction. Therefore, by forming the end portion of the flange portion 7a on the long axis side large enough to absorb the displacement of the inner lid 9, it is possible to secure the airtightness even when the inner lid 9 is displaced.

A heating portion 3 for heating the bottom portion 7 b of the container 7 is provided on the outer wall of the bottom portion of the container storage portion 2 . The heating unit 3 is a heating coil formed by winding a conductive wire such as a copper wire or an aluminum wire. The heating unit 3 generates a magnetic field by the high-frequency current supplied from the inverter unit 28 and induction-heats the container 7 . The contour shape of the heating unit 3 of the present embodiment in plan view is oblong. More specifically, the contour shape of the heating part 3 is an elliptical ring. A plurality of magnetic bodies 4 are arranged below the heating unit 3 . The magnetic body 4 is, for example, ferrite, and concentrates the magnetic flux generated from the heating section 3 .

A through hole is formed in the center of the bottom portion of the container housing portion 2, and a temperature sensor 5 is arranged in the through hole. The temperature sensor 5 is, for example, a thermistor, is supported from below by the compression spring 6 and is arranged in contact with the bottom 7b of the container 7 to detect the temperature of the container 7 . Since the food contained in the container 7 is highly dependent on the temperature, the food can be cooked deliciously by performing heat cooking based on the temperature of the container 7 .

An inner lid ventilation hole 12 is provided through the inner lid 9 , and a communication flow is provided between the inner lid 9 and the outer lid 11 to communicate the inside of the container 7 and the outside of the container 7 via the inner lid ventilation hole 12 . a road is formed. The communication channels are composed of a communication channel 16a, a communication channel 16b, a communication channel 16c, and a communication channel 16d, all of which are hollow. Between the inner lid ventilation hole 12 and the communication passage 16a, a path packing 14 is arranged for hermetically connecting the communication passage 16a to the inner lid ventilation hole 12. As shown in FIG.

A decompression device 15 for decompressing the inside of the container 7 is provided between the communication flow path 16b and the communication flow path 16c. The decompression device 15 is a decompression pump that sucks the air inside the container 7 . In addition, the communication channel has a three-way electromagnetic valve 13 that switches the air channel in the container 7 between a channel A including the communication channel 16b and a channel B including the communication channel 16d. placed. Specifically, the flow path A is a flow path from the inner lid vent hole 12 to the outer lid vent hole 17a opened on the outer surface of the outer lid 11 via the communication flow paths 16a and 16b, the decompression device 15 and the communication flow path 16c. . A flow path B is a flow path from the outer lid ventilation hole 17b to the outer lid ventilation hole 17a via the communication flow paths 16d and 16b, the decompression device 15, and the communication flow path 16c.

The decompression device 15 sucks the air inside the container 7 and exhausts it to the outside through the flow path A and the outer lid ventilation hole 17a. Further, the decompression device 15 sucks outside air through the outer lid ventilation hole 17b and exhausts it to the outside through the outer lid ventilation hole 17a. By arranging the outer lid vent holes 17a and 17b on the side surface or the bottom surface of the outer lid 11, it is possible to prevent moisture and foreign matter from entering the decompression device 15 and reduce the risk of failure. In FIG. 2, the outer lid ventilation holes 17a and 17b are arranged in the outer lid 11 as exhaust holes for exhausting the air in the container 7 to the outside. It may be arranged on the side or the bottom or the like.

By reducing the pressure inside the container 7, the boiling point of the object to be heated can be lowered. By forming the bottom portion 7b of the container 7 into an elliptical shape as in the present embodiment, the area of the bottom portion 7b is increased compared to the case where the bottom portion 7b is formed into a circular shape, and uneven heating tends to occur. On the other hand, by decompressing the inside of the container 7 by the decompression device 15 to lower the boiling point, boiling can be caused from the low temperature range. As a result, the portion with a temperature higher than the boiling point boils at a boiling strength corresponding to the amount of overheating (the difference between the boiling point and the pot temperature), and the heat of evaporation is taken away. can do.

A steam hole 18 is formed in the inner lid 9 and a steam discharge valve 19 is arranged in the steam hole 18 . The steam discharge valve 19 is a valve that is automatically opened and closed by the pressure inside the container 7 to seal or unseal the inside of the container 7 . A cartridge 20 having a steam discharge port 21 is connected downstream of the steam discharge valve 19 with a cartridge packing 22 keeping the passage sealed.

A sensor hole 25 is provided through the inner lid 9 , and a lid sensor 23 and a lid sensor packing 24 for sealing the sensor hole 25 and the outer lid 11 are arranged in the outer lid 11 . . The lid sensor 23 is composed of a thermistor, for example, and detects the temperature inside the container 7 through the sensor hole 25 .

The outer lid 11 is further provided with an operation display device 26 for inputting operation instructions and the like by the user. The operation display device 26 is composed of an operation unit that receives operation input from the user, and a display unit that displays the input information, the operating state of the heating cooker 100, and the like. It should be noted that the operation display device 26 is not limited to the configuration in which the operation section and the display section are integrated, and the display section may be provided separately.

Moreover, although FIG. 2 shows an example in which the operation display device 26 is arranged on the outer lid 11 , the operation display device 26 may be arranged on the main body 1 . Alternatively, the function of the operation display device 26 may be provided to an external device such as a smart phone. In this case, cooking-by-heating appliance 100 is assumed to include a communication unit for communicating with an external device.

A control device 27 that controls the operation of the heating cooker 100 and an inverter section 28 that drives the heating section 3 are arranged in the main body 1 . The control device 27 is composed of a microcomputer and software executed thereon. Alternatively, the control device 27 may be configured with hardware such as a circuit device that realizes its functions. The inverter unit 28 is a drive circuit that converts AC power from a commercial power source into a high-frequency current and supplies the high-frequency current to the heating unit 3 .

FIG. 3 is a control block diagram of the heating cooker 100 of Embodiment 1. As shown in FIG. As shown in FIG. 3, the control device 27 is electrically connected to the steam discharge valve 19, the pressure reducing device 15, the three-way solenoid valve 13, the temperature sensor 5, the lid sensor 23, the operation display device 26, and the inverter section 28. be done. The control device 27 controls the steam discharge valve 19 , the pressure reducing device 15 , the three-way solenoid valve 13 and the inverter section 28 according to the temperatures detected by the temperature sensor 5 and the lid sensor 23 . As a result, the cooking is performed according to the cooking menu input by the user via the operation display device 26 .

Next, heating of the container 7 by the heating unit 3 will be described. First, the heating of the oblong container 70 in the prior art will be described with reference to FIGS. 4 to 6. FIG. Note that the conventional container 70 has an elliptical bottom portion 70b in plan view, and is heated by the heating section 30, which is an annular heating coil. FIG. 4 is a diagram showing the relationship between the distance D from the center C and the temperature of the container 70 when the container 70 is heated by the heating unit 30 in the prior art. FIG. 5 is a diagram for explaining the distance D from the center C of the container 70 in FIG. The distance in FIG. 4 is the distance along the outer wall of the container 70 from the center C of the bottom 70b of the container 70 as shown in FIG.

FIG. 6 is a diagram explaining the spread of heat in the bottom portion 70b of the container 70 in the prior art. 6 is a plan view of the bottom portion 70b of the container 70. FIG. As indicated by arrows in FIG. 6 , the heat generated in the bottom portion 70 b by the induction heating of the heating section 30 spreads in all directions from directly above the heating section 30 . When the heating part 30 is ring-shaped, heat is collected inside the heating part 30 . As a result, as shown in FIG. 4, the inner side of the heating portion 30 in the bottom portion 70b of the container 70, that is, the center side of the container 70, becomes higher in temperature than the outer side, and uneven heating occurs.

Also, when the heating part 30 has an elliptical shape in plan view like the bottom part 70b of the container 70, the heating on the long axis side becomes weaker than the heating on the short axis side due to the interference of the magnetic field. As a result, the intensity of heat generated by the heating portion 30 becomes stronger on the minor axis side, and as a result, the temperature distribution approaches a circular shape. This results in insufficient heating on the long axis side of the bottom portion 70b.

Therefore, the heating section 3 of the present embodiment is arranged so that the outer region 71 of the bottom portion 7b of the container 7 is heated more strongly than the inner region 72 thereof. In other words, the heating unit 3 is arranged so that the amount of heating per unit area in the outer region 71 of the container 7 is greater than the amount of heating per unit area in the inner region 72 .

7A and 7B are diagrams illustrating the outer region 71 and the inner region 72 of the bottom portion 7b of the container 7 according to Embodiment 1. FIG. As shown in FIG. 7, the outer area 71 is an area outside the middle of the bottom portion 7b of the container 7 from the center C to the outer circumference. In addition, the inner area 72 is an area inside the middle of the bottom portion 7b of the container 7 from the center C to the outer periphery.

FIG. 8 is a diagram illustrating the bottom portion 7b of the container 7 according to Embodiment 1. FIG. In the present embodiment, the hatched portion in FIG. 8 is the bottom portion 7b. The bottom portion 7b includes the bottom surface of the container 7 and a portion from the bottom surface to the minimum height of the object to be heated at which dry heating does not occur. More specifically, the portion from the bottom surface of the container 7 to a height of 1 cm is defined as the bottom portion 7b. 1 cm is a guideline for the height of the object to be heated without empty heating, and depending on the shape of the container 7, it may be less than 1 cm or greater than 1 cm.

FIG. 9 is a diagram illustrating the arrangement of the heating unit 3 according to the first embodiment. FIG. 9 shows a specific example in which the heating section 3 is arranged so that the outer region 71 of the bottom portion 7b of the container 7 is heated more strongly than the inner region 72 thereof. FIG. 9 is a plan view of the container 7, the heating unit 3, and the magnetic body 4 as viewed from the bottom side of the cooking device 100. FIG. As shown in FIG. 9, in the present embodiment, a heating unit 3 having an elliptical annular outline is arranged below a bottom portion 7b of an elliptical container 7. As shown in FIG. Further, the heating portion 3 is arranged so that the center of the heating portion 3 coincides with the center of the bottom portion 7b. It should be noted that "match" in this case may include not only perfect match but also error. Moreover, the heating part 3 of the present embodiment is arranged only in the outer region 71 of the bottom part 7b.

The outside of the heating part 3 disperses heat more than the inside, and the temperature is less likely to rise. Therefore, the heating part 3 is arranged up to the vicinity of the outer periphery of the bottom part 7 b of the container 7 . However, the dimension of the heating portion 3 in the minor axis direction is preferably smaller than the dimension of the bottom portion 7b in the minor axis direction. In other words, the flatness of the heating part 3 should be made larger than the flatness of the bottom 7b of the container 7 . As a result, empty heating at the end of the bottom portion 7b on the short axis side can be suppressed.

Furthermore, the heating unit 3 is arranged above the plurality of magnetic bodies 4 . More magnetic bodies 4 are arranged in the long-axis region 73 than in the short-axis region 74 of the bottom 7 b of the container 7 . 10A and 10B are diagrams illustrating the major axis region 73 and the minor axis region 74 of the bottom portion 7b of the container 7 according to Embodiment 1. FIG. As shown in FIG. 10, when the center C of the bottom portion 7b is the center and the major axis of the bottom portion 7b is 0°, the major axis region 73 is ±45° from the major axis. A region other than the long-axis region 73 is defined as a short-axis region 74 . By increasing the number of the magnetic bodies 4 arranged in the major axis region 73 than the number of the magnetic bodies 4 arranged in the minor axis region 74, the magnetic flux caused by induction heating is collected in the longitudinal direction, and heat is generated by interference. can prevent a decline in

In FIG. 9, six magnetic bodies 4 are arranged, but the number of magnetic bodies 4 is not limited to six. 11A and 11B are diagrams illustrating the arrangement of the heating unit 3 in the modification of the first embodiment. FIG. FIG. 11 is a plan view of the container 7, the heating unit 3 and the magnetic body 4 viewed from the bottom side of the cooking device 100. FIG. As shown in FIG. 11, the number of magnetic bodies 4 may be four. When the number of magnetic bodies 4 is four, a region within ±30° from the long axis of the bottom portion 7 b may be the long axis region 73 .

Further, the number of magnetic bodies 4 may be seven or more. When the number of magnetic bodies 4 is 4n+2 (n=0, 1, 2, 3, . . . ), such as 2, 6, 10, 14, . It should be placed on the axis. Arrangement of the magnetic bodies 4 is determined according to the number of the magnetic bodies 4 .

Further, regardless of the number of magnetic bodies 4, the magnetic bodies 4 may not be arranged on the short axis of the bottom part 7b so as not to intensify the heating of the bottom part 7b in the short axis direction. As a result, heat generation in the long axis direction of the bottom portion 7b is stronger than in the short axis direction. In this way, the bottom portion 7b can be uniformly heated by increasing the heating in the long axis direction more than in the short axis direction.

In addition, the heating coil constituting the heating section 3 is wound as densely as possible, but the short axis side of the heating section 3 may be wound more densely than the long axis side. As a result, the width of the heating portion 3 on the short axis side becomes narrower than the width on the long axis side. In other words, the distance between the outer circumference and the inner circumference in the major axis direction of the heating portion 3 is larger than the distance between the outer circumference and the inner circumference in the minor axis direction. Thereby, the long axis side can be heated in a wider range than the short axis side, and uneven heating of the bottom portion 7b can be reduced.

FIG. 12 is a diagram showing temperature changes of the bottom portion 7b of the container 7 according to the first embodiment. 12(a) shows the temperature distribution of the bottom portion 7b before the start of heating, FIG. 12(b) shows the temperature distribution of the bottom portion 7b immediately after the start of heating, and FIG. 12(c) shows the temperature distribution of the bottom portion 7b one minute after the start of heating. shows the temperature distribution of The relationship among the temperatures T1, T2 and T3 shown in FIG. 12 is T1<T2<T3. Moreover, the object to be heated is not stored in the container 7, and the container 7 is in a normal temperature state before the heating is started. "Immediately after the start of heating" means within 3 seconds after the start of heating.

When the heating unit 3 is arranged so that the outer region 71 of the bottom 7b is heated more strongly than the inner region 72 as in the present embodiment, as shown in FIG. The temperature of the outer region 71 is higher than the temperature of the inner region 72 of . One minute after the start of heating, the temperature distribution becomes elliptical as shown in FIG. 12(c). In the present embodiment, the concentration of heat to the inside of the heating portion 3 can be alleviated, and uneven heating of the bottom portion 7b can be suppressed. In addition, heating efficiency is improved by suppressing variations in heating between the short axis side and the long axis side of the bottom portion 7b.

Embodiment 2.
Next, the second embodiment will be described, focusing on changes from the first embodiment. Embodiment 2 is different from Embodiment 1 in that the heating section 3A is composed of an outer heating section arranged in the outer region 71 and an inner heating section arranged in the inner region 72 .

Also in this embodiment, the heating section 3A is arranged so that the outer region 71 of the bottom portion 7b of the container 7 is heated more strongly than the inner region 72 thereof. FIG. 13 is a diagram illustrating the arrangement of the heating section 3A according to the second embodiment. FIG. 13 is a plan view of the container 7, the heating section 3A and the magnetic body 4 viewed from the bottom side of the cooking device 100. FIG. As shown in FIG. 13, the heating section 3A of the present embodiment includes an outer heating coil 3a as an outer heating section and an inner heating coil 3b as an inner heating section.

The outer heating coil 3a and the inner heating coil 3b are formed by winding conductive wires such as copper wires or aluminum wires, for example. The outer heating coil 3a and the inner heating coil 3b have an elliptical annular contour shape, and the oblateness of the outer heating coil 3a and the inner heating coil 3b is formed to be larger than the oblateness of the bottom portion 7b of the container 7 . The outer heating coil 3a and the inner heating coil 3b are arranged such that their centers coincide with the center of the bottom portion 7b. It should be noted that "match" in this case may include not only perfect match but also error.

Heating cooker 100 of the present embodiment includes two inverter units 28 , and outer heating coil 3 a and inner heating coil 3 b are individually driven by separate inverter units 28 . The controller 27 controls each inverter section 28 to alternately drive the outer heating coil 3a and the inner heating coil 3b in order to avoid magnetic flux interference. At this time, the control device 27 controls the inverter section 28 so that the driving time of the outer heating coil 3a is longer than the driving time of the inner heating coil 3b. Thereby, the heating of the outer region 71 can be dominant, and the concentration of heat to the center of the bottom portion 7b can be alleviated. As a result, uneven heating of the bottom portion 7b can be suppressed. Further, by alternately driving the outer heating coil 3a and the inner heating coil 3b, convection of the object to be heated contained in the container 7 can be promoted. It is sufficient that the outer heating coil 3 a mainly heats the outer region 71 and the inner heating coil 3 b mainly heats the inner region 72 . Therefore, part of the outer heating coil 3 a may be arranged in the inner region 72 and part of the inner heating coil 3 b may be arranged in the outer region 71 .

Cooking device 100 of the present embodiment also includes two temperature sensors 5a and 5b. The temperature sensor 5a is arranged in the inner area 72 of the bottom part 7b and the temperature sensor 5b is arranged in the outer area 71 of the bottom part 7b. More specifically, the temperature sensor 5a is located on the long axis of the bottom part 7b and in the middle of the bottom part 7b, the temperature sensor 5b is located on the long axis of the bottom part 7b, the outer heating coil 3a and the inner heating coil 3b. As described above, temperature unevenness in the oblong bottom portion 7b is more likely to occur in the long axis direction than in the short axis direction. Therefore, by arranging the temperature sensor 5a and the temperature sensor 5b at different positions on the long axis of the bottom portion 7b, the temperature unevenness detection accuracy is improved. If the temperature sensor 5b is provided on the long axis of the bottom portion 7b, the magnetic body 4 cannot be arranged on the long axis. In this case, the number of magnetic bodies 4 should be 4n (n=1, 2, 3, . . . ), such as 4, 8, 12, 16, .

Temperature sensors 5 a and 5 b are electrically connected to control device 27 . Control device 27 controls inverter section 28 based on the temperatures detected by temperature sensors 5a and 5b. Specifically, the control device 27 compares the temperature detected by the temperature sensor 5a and the temperature detected by the temperature sensor 5b. Then, when the difference between the temperature detected by the temperature sensor 5a and the temperature detected by the temperature sensor 5b is equal to or greater than the threshold, the inverter unit 28 is controlled so that the difference becomes equal to or less than the threshold. For example, when the temperature detected by the temperature sensor 5a is higher than the temperature detected by the temperature sensor 5b by a threshold value or more, the driving time of the outer heating coil 3a is increased or the driving time of the inner heating coil 3b is decreased. On the other hand, when the temperature detected by the temperature sensor 5a is lower than the temperature detected by the temperature sensor 5b by a threshold value or more, the driving time of the outer heating coil 3a is decreased or the driving time of the inner heating coil 3b is increased.

In Embodiment 1, the heating control is performed based on the central temperature of the bottom portion 7 b of the container 7 detected by one temperature sensor 5 . In such a configuration, if the temperature at the center of the bottom portion 7b is lower than the temperature at the outer peripheral side, the temperature of the object to be heated will rise too much if the temperature is adjusted based on the temperature detected by the temperature sensor 5. On the other hand, in the present embodiment, two temperature sensors 5a and 5b are arranged in the inner region 72 and the outer region 71, respectively, and the temperature unevenness of the bottom portion 7b is detected and feedback control is performed, whereby the temperature of the bottom portion 7b is The temperature can be made uniform. As a result, in the heat cooker 100, the temperature can be accurately adjusted in a sequence for adjusting the temperature at a constant temperature.

The arrangement of the outer heating coil 3a and the inner heating coil 3b in this embodiment is not limited to the example of FIG. FIG. 14 is a diagram illustrating the arrangement of the heating section 3A in the modification of the second embodiment. As shown in FIG. 14, the shape of the inner heating coil 3b may be closer to a circular shape than the shape of the outer heating coil 3a. The shape closer to a circle than the shape of the outer heating coil 3a means that the oblateness of the outer heating coil 3a is larger than the oblateness of the inner heating coil 3b. Also, the inner heating coil 3b is arranged so that its center coincides with the center of the bottom portion 7b. More preferably, the inner heating coil 3b is arranged so as to be located in the middle of the distance from the center of the bottom portion 7b to the inner circumference of the outer heating coil 3a.

The concentration of heat to the inside of the heating portion 3A is more influenced by the heating coil on the short axis side than on the long axis side. Therefore, by making the shape of the inner heating coil 3b closer to a circular shape than the outer heating coil 3a, the long axis side can be evenly heated without changing the heating position on the short axis side. This leads to reduction of uneven heating of the bottom portion 7b.

Alternatively, one inverter section 28 may drive the outer heating coil 3a and the inner heating coil 3b. In this case, by increasing the number of turns of the outer heating coil 3a than the number of turns of the inner heating coil 3b, the heating of the vicinity of the outer periphery of the bottom 7b of the container 7 is enhanced, and the heat is concentrated inside the heating section 3A. can be mitigated. By driving the outer heating coil 3a and the inner heating coil 3b with one inverter unit 28, the effects of the second embodiment can be achieved and the cost of the heating cooker 100 can be reduced.

Embodiment 3.
Next, the third embodiment will be described, focusing on differences from the first embodiment. Embodiment 3 is different from Embodiment 1 in that heating unit 3B is a heater. More specifically, the heating unit 3B is an electric heater such as a sheathed heater, and power supply is controlled by the control device 27 .

If the heating section 3B is a heater, it is considered that the output is substantially the same over the entire surface area of the heating section 3B. In this case, even if the heating section 3B is horizontally long, the heat spreads in a circular shape, and as a result, the temperature distribution by the heating section 3B becomes nearly circular. Therefore, if the heating part 3B is arranged so that the short axis side of the bottom part 7b is not heated dry, uneven heating occurs between the long axis side and the short axis side of the bottom part 7b.

Therefore, in the present embodiment as well, the heating section 3B is arranged so that the outer region 71 of the bottom portion 7b of the container 7 is heated more strongly than the inner region 72 thereof. As in Embodiment 1, the inner region 72 is a region inside the middle from the center C to the outer periphery of the bottom 7b of the container 7, and the inner region 72 extends from the center C to the outer periphery of the bottom 7b of the container 7. is the region outside the middle of the .

15A and 15B are diagrams for explaining the arrangement of the heating unit 3B according to the third embodiment. FIG. 15 shows a specific example of arranging the heating section 3B such that the outer region 71 of the bottom 7b of the container 7 is heated more strongly than the inner region 72 thereof. FIG. 15 is a plan view of the container 7 and the heating unit 3B viewed from the bottom side of the cooking device 100. FIG. As shown in FIG. 15, the heating portion 3B of the present embodiment is an elliptical heater in plan view, and an elliptical hole 35 is provided in the center of the heating portion 3B. Further, the heating portion 3B is arranged so that the center of the heating portion 3B and the center of the hole 35 are aligned with the center of the bottom portion 7b. It should be noted that "match" in this case may include not only perfect match but also error. Also, the contour shape of the heating part 3B can be said to be an elliptical ring.

The heating portion 3B is arranged such that the hole 35 is located in the inner region 72 of the bottom portion 7b. As a result, the outer region 71 of the bottom portion 7b of the container 7 can be heated more strongly than the inner region 72 thereof. The size and shape of the hole 35 are not limited to the example of FIG. 15, and the hole 35 may be circular or polygonal. Further, the flatness of the heating part 3B is formed so as to be larger than the flatness of the bottom part 7b of the container 7 . Thereby, empty heating of the short axis side end of the container 7 can be suppressed. Also, the width of the heating portion 3B on the long axis side may be formed narrower than the width on the short axis side. As a result, uneven heating can be suppressed by heating the long-axis side over a wider range than the short-axis side.

Even when the heating portion 3B is a heater as in the present embodiment, by arranging the heating portion 3B so that the outer region 71 of the bottom portion 7b is heated more strongly than the inner region 72, Heat concentration of the bottom portion 7b can be alleviated, and uneven heating of the bottom portion 7b can be suppressed. As a result, the bottom portion 7b is uniformly heated, and the heating efficiency is also improved.

FIG. 16 is a diagram illustrating the arrangement of the heating unit 3C in Modification 1 of Embodiment 3. As shown in FIG. As shown in FIG. 16, the heating section 3C may be composed of an outer heater 3d as an outer heating section and an inner heater 3e as an inner heating section. The outer heater 3d and the inner heater 3e are elliptical heaters in a plan view, and elliptical holes 35d and 35e are provided in the center, respectively. The inner heater 3e is arranged in the hole 35d of the outer heater 3d.

The outer heater 3 d and the inner heater 3 e are formed so as to have an oblateness larger than that of the bottom portion 7 b of the container 7 . Also, the outer heating coil 3a and the inner heating coil 3b are arranged so that their centers coincide with the center of the bottom portion 7b. It should be noted that "match" in this case may include not only perfect match but also error.

The outer heater 3d and the inner heater 3e are electrically connected to the control device 27, and the power supply is controlled by the control device 27. FIG. The control device 27 controls power supply so that the amount of heating by the outer heater 3d is greater than the amount of heating by the inner heater 3e. As a result, the outer region 71 of the bottom portion 7b of the container 7 can be heated more strongly than the inner region 72 thereof.

Furthermore, FIG. 17 is a diagram illustrating the arrangement of the heating unit 3C in Modification 2 of Embodiment 3. As shown in FIG. As shown in FIG. 17, the shape of the inner heater 3e may be closer to a circular shape than the shape of the outer heater 3d. The shape closer to a circle than the shape of the outer heater 3d means that the flatness of the outer heater 3d is larger than the flatness of the inner heater 3e. Also, the inner heater 3e is arranged so that its center coincides with the center of the bottom portion 7b. More preferably, the inner heater 3e should be arranged in the middle of the distance from the center of the bottom portion 7b to the inner circumference of the outer heater 3d.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and can be modified in various ways without departing from the gist of the present invention. For example, the three-way solenoid valve 13, the pressure reducing device 15, the communication channels 16a to 16d, and the outer lid ventilation holes 17a and 17b in the heating cooker 100 are not essential and may be omitted. Moreover, Embodiments 1 to 3 and their modifications can be combined arbitrarily. For example, in Embodiments 1 and 3, the two temperature sensors 5a and 5b in Embodiment 2 may be provided. Then, as in the second embodiment, feedback control similar to that in the second embodiment may be performed based on the temperatures detected by the two temperature sensors 5a and 5b. Alternatively, the heating of the heating unit 3 may be controlled based on the average value of the temperatures detected by the two temperature sensors 5a and 5b. As a result, it is possible to suppress deviation in temperature control due to uneven heating.

Also, the heating cooker 100 may be provided with a side heating unit for heating the side surface. The side heating portion may be either a heating coil or a heater. Thereby, heating of the sides of the container 7 is possible. However, in this case, the side heating section should be arranged close to the heating section 3 in order to prevent empty heating. Specifically, the side heating part is preferably arranged in the lower part of the container 7 in a range that affects the heating of the bottom part 7b. Further, the control device 27 may control the heating time of the side heating portion to be longer than the heating time of the heating portion 3 . Since the side heating portion is located outside the bottom portion 7b relative to the heating portion 3, the heating of the side heating portion is stronger than that of the heating portion 3, thereby increasing the heating of the outside of the bottom portion 7b. Thereby, the concentration of heat to the central portion of the bottom portion 7b can be suppressed, and uneven heating can be reduced.

Furthermore, in the above-described embodiment, as an example of the oblong bottom portion 7b, the case where the bottom portion 7b has an elliptical shape in plan view has been described, but the shape of the bottom portion 7b is not limited to an elliptical shape. For example, the bottom portion 7b of the container 7 may be rectangular or diamond-shaped in plan view. FIG. 18 is a diagram illustrating the outer area 71 and the inner area 72 when the bottom portion 7b of the container 7 is rectangular. As shown in FIG. 18, even when the bottom 7b of the container 7 is rectangular, the inner region 72 is a region inside the middle of the bottom 7b of the container 7 from the center C to the outer periphery, and the outer region 71 is the container It is a region outside the middle from the center C of the bottom portion 7b of 7 to the outer periphery.

Also in this case, the heating unit 3 is arranged so that the outer region 71 of the bottom portion 7b of the container 7 is heated more strongly than the inner region 72 thereof. Specifically, the heating unit 3 has a shape similar to that of Embodiments 1 to 3 and their modifications, and is arranged similarly. In addition, the contour shape of the heating unit 3 in a plan view is not limited to an elliptical shape, and may be a rectangular annular shape or a rectangular shape. When the bottom portion 7b is rectangular, the straight line parallel to the long side passing through the center of the bottom portion 7b is synonymous with the "major axis" in the case of an elliptical shape, and the straight line parallel to the short side passing through the center of the bottom portion 7b is synonymous with the elliptical shape. is synonymous with the "minor axis" of

1 main body, 2 container storage part, 3, 3A, 3B, 3C, 30 heating part, 3a outer heating coil, 3b inner heating coil, 3d outer heater, 3e inner heater, 4 magnetic material, 5, 5a, 5b temperature sensor, 6 compression spring 7, 70 container 7a flange portion 7b, 70b bottom portion 71 outer region 72 inner region 73 long axis region 74 short axis region 8 grip portion 9 inner lid 10 lid packing 11 outer lid, 12 inner lid vent, 13 three-way solenoid valve, 14 path packing, 15 decompression device, 16a, 16b, 16c, 16d communication flow path, 17a, 17b outer lid vent, 18 steam hole, 19 steam discharge valve, 20 cartridge, 21 steam outlet, 22 cartridge packing, 23 lid sensor, 24 lid sensor packing, 25 sensor hole, 26 operation display device, 27 control device, 28 inverter section, 35, 35d, 35e hole, 100 heating cooker.

Claims (14)

a container having an oblong bottom;
a main body that houses the container;
a horizontally long heating unit that heats the container;
and a plurality of magnetic bodies arranged below the heating unit ,
The heating unit is arranged such that an outer region of the bottom of the container is heated more strongly than an inner region,
The outer region is a region outside the middle from the center to the outer periphery of the bottom,
The inner region is a region inside the middle from the center to the outer periphery of the bottom ,
The heating unit is a heating coil that induction-heats the container,
The plurality of magnetic bodies are disposed more in the major axis area than in the minor axis area of the bottom,
The long axis region is a region of ±45° from the long axis when the center of the bottom is the center and the long axis of the bottom is 0°,
The heating cooker , wherein the short axis region is a region other than the long axis region . The heating cooker according to claim 1, wherein the flatness of the heating portion is larger than the flatness of the bottom portion of the container. 3. The heating cooker according to claim 1, wherein the magnetic body is not arranged on the minor axis of the bottom. the heating portion has an annular profile,
The heating cooker according to any one of claims 1 to 3 , wherein the distance between the outer circumference and the inner circumference in the longitudinal direction of the heating portion is greater than the distance between the outer circumference and the inner circumference in the minor axis direction. The heating cooker according to any one of claims 1 to 4 , wherein the heating section is not arranged in the inner region. The heating cooker according to any one of claims 1 to 4 , wherein the heating section comprises an inner heating section arranged in the inner region and an outer heating section arranged in the outer region. 7. The heating cooker according to claim 6 , further comprising a control device that controls the heating unit such that the heating time of the outer heating unit is longer than the heating time of the inner heating unit. The heating cooker according to claim 6 or 7 , wherein the flatness of the outer heating portion is larger than the flatness of the inner heating portion. the inner heating section is an inner heating coil and the outer heating section is an outer heating coil;
The heating cooker according to any one of claims 6 to 8 , wherein the number of turns of the outer heating coil is larger than the number of turns of the inner heating coil. Further comprising a plurality of temperature sensors for detecting the temperature of the bottom,
The heating cooker according to any one of claims 1 to 9 , wherein the plurality of temperature sensors are arranged on the long axis of the bottom portion. The heating cooker according to any one of claims 1 to 10 , further comprising a decompression device that decompresses the inside of the container. The heating cooker according to any one of claims 1 to 11 , wherein a gripping portion is provided at the longitudinal end of the container. The heating cooker according to any one of claims 1 to 12 , further comprising a side heating portion that heats a side surface of the container. 14. The heating cooker according to claim 13 , further comprising a control device that controls the side heating portion so that the heating time of the side heating portion is longer than the heating time of the heating portion.

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