Wireless induction heating cooker with improved heat conduction efficiency

Abstract

A wireless induction heating cooker includes a main body configured to receive and heat food objects therein, a lid configured to couple to an upper surface of the main body, and an inner pot configured to be accommodated in the main body and to be heated based on a magnetic field being generated by a heating coil of an induction heating device. The inner pot defines a heat conduction space that is surrounded by a bottom surface, an outer surface, and an inner surface of the inner pot.

Claims

1. A wireless induction heating cooker comprising: a main body configured to receive and heat food objects therein; a lid configured to couple to an upper surface of the main body; and an inner pot configured to be accommodated in the main body and to be heated based on a magnetic field being generated by a heating coil of an induction heating device, wherein the inner pot defines a heat conduction space that is surrounded by a bottom surface, an outer surface, and an inner surface of the inner pot, wherein the inner pot has (i) a first part that extends downward to a preset depth and defines a first inner diameter that is constant and (ii) a second part that extends downward from the preset depth toward the bottom surface of the inner pot and defines a second inner diameter that decreases as a depth of the inner pot increases toward the bottom surface of the inner pot, and wherein an outer diameter of the inner pot is constant at the first and second parts of the inner pot.

2. The wireless induction heating cooker of claim 1, wherein the lid is coupled to the main body by a hinge and configured to open and close the upper surface of the main body, the lid being configured to be detached from the main body.

3. The wireless induction heating cooker of claim 1, wherein the inner pot is configured to transfer heat generated on the bottom surface of the inner pot in a direction upward through the heat conduction space.

4. The wireless induction heating cooker of claim 1, wherein the inner pot has a cylindrical shape and defines a pot opening at an upper surface thereof, and wherein the bottom surface of the inner pot has a flat shape and is configured to contact a bottom surface of the main body.

5. The wireless induction heating cooker of claim 1, wherein an area of the bottom surface of the inner pot is less than an area defined by the heating coil of the induction heating device.

6. The wireless induction heating cooker of claim 1, wherein the inner pot comprises a rounding portion that is disposed on the inner surface of the inner pot and that extends from an outer edge of the bottom surface of the inner pot.

7. The wireless induction heating cooker of claim 1, wherein the inner pot extends along a vertical center line, and wherein a horizontal distance between the vertical center line and the outer surface of the inner pot is constant.

8. The wireless induction heating cooker of claim 1, wherein a horizontal distance between the outer surface of the inner pot and the inner surface of the inner pot increases as the depth of the inner pot increases toward the bottom surface of the inner pot.

9. The wireless induction heating cooker of claim 8, wherein the horizontal distance between the inner surface and the outer surface of the inner pot is greater than a vertical thickness of the bottom surface of the inner pot.

10. The wireless induction heating cooker of claim 1, further comprising: a heat conduction member disposed in the heat conduction space, herein a thermal conductivity of the heat conduction member is greater than a thermal conductivity of the inner pot.

11. The wireless induction heating cooker of claim 10, wherein the inner pot is made of cast iron or stainless steel, and the heat conduction member is made of copper or aluminum.

12. The wireless induction heating cooker of claim 10, wherein the heat conduction member extends along a depth direction of the inner pot.

13. The wireless induction heating cooker of claim 12, wherein the heat conduction member has one end that is horizontally bent and extends into the heat conduction space.

14. The wireless induction heating cooker of claim 10, wherein the heat conduction member extends vertically along the outer surface of the inner pot.

15. The wireless induction heating cooker of claim 10, wherein the heat conduction member comprises: a first portion that extends along the outer surface of the inner pot; and a second portion that is curved from a lower end of the first portion toward the inner surface of the inner pot and that extends into the heat conduction space.

16. The wireless induction heating cooker of claim 10, wherein the heat conduction member is disposed vertically above the bottom surface of the inner pot.

17. The wireless induction heating cooker of claim 10, wherein an outer surface of the heat conduction member is flush with the outer surface of the inner pot.

18. The wireless induction heating cooker of claim 10, wherein the heat conduction member has a ring shape that extends along a circumferential direction of the inner pot.

19. The wireless induction heating cooker of claim 18, wherein the heat conduction member surrounds a lower portion of the outer surface of the inner pot.

20. The wireless induction heating cooker of claim 1, wherein the bottom surface of the inner pot is defined by a metal material and configured to be heated based on the magnetic field being generated by the heating coil.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a side cross-sectional view showing an induction heating cooker in related art.

(2) FIG. 2A is a perspective view showing an inner pot in related art.

(3) FIG. 2B is a side cross-sectional view showing the inner pot in FIG. 2A.

(4) FIG. 3 shows an example of a wireless induction heating cooker configured to be operated on an induction heating device.

(5) FIG. 4A is a perspective view showing an example of an inner pot.

(6) FIG. 4B is a side cross-sectional view showing the inner pot in FIG. 4A.

(7) FIGS. 5 and 6 show examples of comparison between a heat conduction performance of the inner pot in related art in FIG. 2A and a heat conduction performance of the inner pot of the present disclosure in FIG. 4A.

(8) FIG. 7 is a graph showing an example of temperature changes with respect to heights of the inner pot in related art in FIG. 2A and the inner pot of the present disclosure in FIG. 4A.

(9) FIGS. 8A and 8B show examples of heat conduction members provided in heat conduction spaces.

(10) FIG. 9 shows an example of comparison between the heat conduction performances of the inner pot in FIG. 4A and the inner pot in FIGS. 8A and 8B.

(11) FIG. 10 is a graph showing an example of temperature changes with respect to heights of the inner pot in FIG. 4A and inner pots in FIGS. 8A and 8B.

DETAILED DESCRIPTION

(12) The above-mentioned objects, features, and advantages of the present disclosure are described in detail with reference to the accompanying drawings. Accordingly, the skilled person in the art to which the present disclosure pertains may easily implement the technical idea of the present disclosure. In the description of the present disclosure, if it is determined that a detailed description of a well-known relevant technology of the present disclosure may unnecessarily obscure the gist of the present disclosure, the detailed description thereof is omitted. One or more implementations of the present disclosure are described in detail with reference to the accompanying drawings. In the drawings, same reference numerals are used to refer to same or similar components.

(13) The present disclosure relates to a wireless induction heating cooker that may improve heat conduction efficiency of an inner pot configured to be heated through an induction heating method.

(14) One or more examples of a wireless induction heating cooker are described below in detail with reference to FIGS. 3 to 10.

(15) FIG. 3 shows an example wireless induction heating cooker that operates on an induction heating device.

(16) FIG. 4A is a perspective view showing an example inner pot. FIG. 4B is a side cross-sectional view showing the inner pot in FIG. 4A.

(17) FIGS. 5 and 6 show an example of comparison between heat conduction performance of the inner pot in related art in FIG. 2A and heat conduction performance of the inner pot of the present disclosure shown in FIG. 4A. FIG. 7 is a graph showing an example of a temperature change with respect to a height of the inner pot in related art in FIG. 2A and the inner pot of the present disclosure in FIG. 4A.

(18) FIGS. 8A and 8B show examples of heat conduction members provided in heat conduction spaces.

(19) FIG. 9 shows an example of comparison between heat conduction performance of the inner pot in FIG. 4A and heat conduction performance of inner pots in FIGS. 8A and 8B. FIG. 10 shows a graph corresponding to temperature changes of the inner pot in FIG. 4A and inner pots in FIGS. 8A and 8B with respect to heights of the inner pot in FIG. 4A and inner pots in FIGS. 8A and 8B.

(20) Referring to FIG. 3, the wireless induction heating cooker 1 includes a main body 10, a lid 20 and an inner pot 30, and the lid 20 may include a controller 21, a communicator 22, a pressure weight 23, a noise reducer 24, and a steam exhauster 25. The wireless induction heating cooker 1 shown in FIG. 3 is according to one implementation, and components of the wireless induction heating cooker 1 are not limited to examples shown in FIG. 3, and some components can be added, changed or deleted as necessary.

(21) In some implementations, the wireless induction heating cooker 1 may operate on any induction heating device that heats an object through an electromagnetic induction phenomenon.

(22) As shown in FIG. 3, the wireless induction heating cooker 1 may be placed on an upper plate U.P. of any induction heating device including a heating coil H.C. and may be operated. In some examples, the wireless induction heating cooker 1 may be placed on the upper plate U.P. and may be placed on a vertical line of the heating coil H.C. and may be operated.

(23) A current may flow through the heating coil H.C. under the control of the induction heating device, and thus the heating coil H.C. may generate a magnetic field. Current may be induced in the inner pot 30 based on the magnetic field generated by the heating coil H.C. to heat the inner pot 30 based on the induced current.

(24) The main body 10 may be a case that supports a lower portion and a side portion of the wireless induction heating cooker 1. For example, the main body 10 may have a cylindrical shape with an opened upper portion of the main body 10, and cooking may be performed in the main body 10. In other words, the main body 10 may be configured to receive and heat food objects therein. In some examples, the inner pot 30 described below may be accommodated in the main body 10, and various types of grains such as rice may be cooked inside the inner pot 30. The main body 10 may define a body opening at an upper surface thereof, and the body opening may receive the inner pot 30 therethrough. The inner pot 30 may define a pot opening at an upper surface thereof, and the pot opening may receive food items therethrough.

(25) The lid 20 is a case that seals an upper portion of the wireless induction heating cooker 1 and may be fastened to the upper surface of the main body 10. In this case, the lid 20 may be fastened to the upper surface of the main body 10 to be opened and closed with respect to the upper surface of the main body 10.

(26) For example, the lid 20 may be coupled to the main body 10 using a hinge to be selectively opened and closed. In some examples, the lid 20 may be coupled to a hinge shaft provided at an edge of one surface of an upper portion of the main body 10 and selectively opened and closed with respect to the upper surface of the main body 10 by rotating about the hinge shaft.

(27) In some implementations, the lid 20 may be removed from the main body 10. In some examples, the lid 20 may be coupled to the upper surface of the main body 10 using a plurality of fastening members at an upper edge of the main body 10. In this case, the lid 20 may be completely separated from the main body 10.

(28) As shown in FIG. 3, the lid 20 may include a controller 21 that controls operation of the wireless induction heating cooker 1, and a communicator 22 that performs data communication with the above-described induction heating device. The controller 21 and the communicator 22 may be implemented with a printed circuit board (PCB) including a plurality of integrated circuits (ICs).

(29) In some cases, the lid 20 may include a pressure weight 23 that maintains an internal pressure of the wireless induction heating cooker 1 at a constant pressure, and a noise reducer 24 including a plurality of sound absorbing members that reduce noise generated during exhaust of steam.

(30) In some cases, the lid 20 may include a steam exhauster 25 (e.g., a solenoid valve) that exhausts the steam inside the wireless induction heating cooker 1 based on a specific control signal.

(31) Elements provided in the lid 20 are not limited to the above-described components. For example, the lid 20 may further include a touch panel and a display. The touch panel may receive operation of users. The display may indicate an operation state of the wireless induction heating cooker 1.

(32) The inner pot 30 may be accommodated in the main body 10 and may be heated based on a magnetic field generated by the heating coil H.C. of the induction heating device.

(33) In some cases, where the wireless induction heating cooker 1 is placed above the induction heating device, a lower surface of the inner pot 30 may be spaced apart from the heating coil H.C. by a predetermined distance and a bottom surface 31 of the main body 10 may be disposed between the lower surface of the inner pot 30 and the heating coil H.C. Based on the current flowing through the heating coil H.C., the magnetic field generated by the heating coil H.C. may induce a current in the inner pot 130, and Joule's heat may be generated in the inner pot 130 based on the induced current.

(34) In order to generate the induced current in the inner pot 30, the inner pot 130 may include any magnetic component. For example, the inner pot 130 may be made of a cast iron containing iron (Fe), and may be made of a clad in which iron (Fe), aluminum (Al), stainless steel, and the like, are bonded.

(35) As shown in FIG. 4A, the inner pot 30 may include a bottom surface (an outer bottom surface 31) horizontally facing the heating coil H.C., an outer surface 32 that contacts an inner surface of the main body 10, and an inner surface 33 contacting the food.

(36) In this structure, the inner pot 30 may include a heat conduction space HA surrounded by the bottom surface 31, the outer surface 32, and the inner surface 33 of the inner pot 30.

(37) The heat conduction space HA may filled with a material having high thermal conductivity. In some examples, the heat conduction space HA may define a portion of the inner pot 30 and may be made of the same material as the inner pot 30, and an independent space of the inner pot 30, and may be made of different material from material of the inner pot 30. It is described below assuming that the heat conduction space HA is integrated with the inner pot 30 and is made of the same material as the inner pot 30.

(38) Referring to FIGS. 4A and 4B, the inner pot 30 may have a cylindrical shape with an open upper surface of the inner pot 30, and the bottom surface 31 of the inner pot 30 may have a flat shape in close contact with the bottom surface of the main body 10. In other words, in contrast to the inner pot 30′ in related art described with reference to FIGS. 2A and 2B, the inner pot 30 of the present disclosure may have a flat bottom surface 31 so that an entire surface of the bottom surface 31 of the inner pot 30 may closely contact the bottom surface of the main body 10.

(39) In this case, an area of the bottom surface 31 may be less than an area of the region formed by the heating coil H.C. The region formed by the heating coil H.C. may be a minimum area that may include all portions of the heating coil H.C.

(40) Referring to FIG. 3, in one example, the heating coil H.C. may be a circular flat coil. In this case, the area of the region formed by the heating coil H.C. may be an area of a circle determined by a coil radius Rc, which is a distance from a center of the heating coil H.C. to an outer circumferential surface of the heating coil H.C.

(41) In some examples, as shown in FIG. 4B, an area of the bottom surface 31 may correspond to an area of a circle determined by an outer diameter Ro of the inner pot 30, which is a distance between a center vertical line HL of the inner pot 30 and the outer surface 32.

(42) In this case, the area of the circle determined by the outer diameter Ro of the inner pot 30 may be less than the area of the circle determined by the coil radius Rc. Accordingly, the magnetic field generated by the heating coil H.C. may be transmitted to the bottom surface 31 of the inner pot 30 in the area where the inner pot 30 is disposed without leakage.

(43) In some implementations, the magnetic field generated by the heating coil H.C. may be transmitted to the bottom surface 31 of the inner pot 30 without leakage, so that the induction heating device may generate all output to increase the temperature of the inner pot 30, thereby improving the heat transfer efficiency between devices.

(44) Through the above structure, heat may be generated in the bottom surface 31 of the inner pot 30 through the electromagnetic induction phenomenon, and the heat generated in the bottom surface 31 of the inner pot 30 may be transferred upward of the inner pot 30 through a heat conduction space HA.

(45) In some examples, as shown in FIG. 4B, the heat conduction space HA may be defined at a side end of the inner pot 30 in a radial direction with respect to the center vertical line HL of the inner pot 30. The heat generated in the bottom surface 31 may be transferred upward along the side end of the inner pot 30 through the heat conduction space HA, so that the heat may also be transferred to other portions of the inner pot 30 which are not adjacent to the bottom surface 31.

(46) In order to improve the heat conduction efficiency with respect to the heat conduction space HA, a rounding portion RA may be disposed on the inner surface 33 adjacent to the edge of the bottom surface 31.

(47) As shown in FIG. 4B, the rounding portion RA may be adjacent to an edge to form a circumference of the bottom surface 31. In other words, an inner diameter Ri of the inner pot 30 corresponds to a distance between a center vertical line HL of the inner pot 30 and the inner surface 33 of the inner pot 30. The inner diameter Ri of the inner pot 30 has a predetermined inner diameter level to a preset depth and is gradually reduced at portions of the inner pot 30 having a preset depth or more and is gradually reduced with respect to the depth of the inner pot 30. The inner diameter Ri of the inner pot 30 may be a minimum inner diameter Ri′ of the inner pot 30 on the inner bottom surface of the inner pot 30.

(48) In some implementations, an outer diameter Ro of the inner pot 30, which is a horizontal distance between the center vertical line HL and the outer surface 32 of the inner pot 30, may have a constant outer diameter level regardless of the depth of the inner pot 30. In other words, the outer surface 32 of the inner pot 30 may be parallel to the central vertical line HL of the inner pot 30 regardless of the depth of the inner pot 30.

(49) In some cases, where the rounding portion RA is disposed in the inner pot 30, and the outer diameter Ro of the inner pot 30 has a constant diameter level, the horizontal distance between the outer surface 32 and the inner surface 33, of the inner pot 30, may increase as the depth of the inner pot 30 increases.

(50) Referring back to FIG. 4B, the horizontal distance Rd between the outer surface 32 and the inner surface 33 of the inner pot 30 may increase as the depth of the inner pot 30 is greater from a portion at which the rounding portion RA is disposed to an inner bottom surface of the inner pot 30. In some examples, a horizontal distance Rd may be greater than a horizontal distance Rd′. The horizontal distance Rd is a distance between the outer surface 32 and the inner surface 33 of the inner pot 30 determined at a portion of the inner pot 30 having a relatively less depth. The horizontal distance Rd′ is a distance between the outer surface 32 and the inner surface 33 of the inner pot 30 determined at a portion of the inner pot 30 having a relatively greater depth of the inner pot 30. The horizontal distance Rd may be greater than a vertical thickness of the bottom surface 31, and define a maximum sidewall thickness at a position facing the bottom surface 31.

(51) The heat conduction efficiency of the inner pot of the present disclosure may be greatly improved through the above-mentioned structure compared to the inner pot 30′ in related art.

(52) FIGS. 5 and 6 show example temperatures of inner pots 30′ and 30 with respect to heights of inner pots 30′ and 30 determined based on heating the inner pots 30′ and 30 at lower portions of the inner pots 30′ and 30 with a same power (e.g., 1000 W), where the inner pot 30′ in related art in FIG. 2A may be made of a same material (e.g., clad), for comparison, as a material of the inner pot 30 of the present disclosure in FIG. 4A.

(53) FIGS. 5 and 6 show that, in the case of the inner pot 30′ in related art, the bottom surface 31 of the inner pot 30′ is heated to 186° C., but the upper portion of the inner pot 30′ is only heated to 122° C. The temperature differences between surfaces of the inner pot 30′ is a maximum of 64° C., which is greater.

(54) By contrast, in the case of the inner pot 30 of the present disclosure, the bottom surface 31 of the inner pot 30 is heated to 167° C., and the upper portion of the inner pot 30 is heated to 125° C., so that temperate differences between the two surfaces of the inner pot 30 is a maximum of 42° C. The temperature difference between the two surfaces of the inner pot 30 of the present disclosure are reduced by 22° C. compared to the inner pot 30′ in related art. In other words, according to the present disclosure, the inner pot 30 of the present disclosure has improved temperature distribution uniformity than the inner pot 30′ in related art.

(55) FIG. 7 shows a graph corresponding to a temperature (T′) of the inner pot 30′ in related art in FIG. 2A and a temperature (T) of the inner pot 30 of the present disclosure in FIG. 4A with respect to heights of the inner pots 30′ and 30.

(56) Referring to FIG. 7, according to the present disclosure, a temperature of the inner pot 30 measured a portion of the inner pot having a relatively less height is reduced (in a direction of arrow A) compared to the inner pot 30′ in related art and the temperature of the inner pot 30 measured at a portion of the inner pot having a relatively greater height may be increased (in a direction of arrow B) compared to the inner pot 30′ in related art, thereby providing temperature distribution uniformity of the inner pot 30.

(57) As described above, according to the present disclosure, the position of the inner space of the inner pot 30, which may not be directly heated through the induction heating method, may also be heated, thereby improving the uniformity in the inner temperature of the inner pot 30 and improving cooking quality.

(58) In order to improve heat conduction efficiency with respect to the heat conduction space HA, the heat conduction member 34 having a higher thermal conductivity than the material of the heat conduction space HA may be provided in the heat conduction space HA.

(59) The heat conduction member 34 may be made of a material different from the material of the heat conduction space HA. For example, when the heat conduction space HA is made of cast iron or stainless steel, the heat conduction member 34 may be made of copper (Cu) or aluminum (Al) having a relatively higher thermal conductivity than the thermal conductivity of the heat conduction space HA.

(60) The heat conduction member 34 may be provided at any position inside the heat conduction space HA.

(61) For example, the heat conduction member 34 may include a plurality of members having a predetermined arc length along a circumferential direction of the inner pot 30. In some examples, the heat conduction member 34 may include a plurality of members having a central angle of 30° with respect to the center vertical line HL of the inner pot 30. In this case, the heat conduction members 34 may be spaced apart by a predetermined center angle.

(62) As another example, the heat conduction member 34 may be disposed in the heat conduction space HA and may have an integrated ring shape extending along the circumferential direction of the inner pot 30. As shown in FIG. 4B, the heat conduction space HA may be defined along the circumferential direction of the inner pot 30. In this case, the heat conduction member 34 may be disposed in the heat conduction space and may have a ring shape extending along the circumferential direction of the inner pot 30. In other words, the heat conduction member 34 may include a single ring-shaped member having a center angle of 360° with respect to the center vertical line HL of the inner pot 30.

(63) The heat conduction member 34 may be disposed in the heat conduction space HA and may extend along a depth direction of the inner pot 30.

(64) Referring to FIG. 8A, for example, the inner pot 30a may include a heat conduction member 34 that is disposed in the heat conduction space HA and extends along the depth direction of the inner pot 30a. In some examples, as shown in the side cross-sectional view of the inner pot 30a, the heat conduction member 34 may have an I-shape.

(65) The length of the heat conduction member 34 extending in the depth direction of the inner pot 30a is not limited. For example, the heat conduction member 34 may have one or a first end adjacent to the bottom surface 31 may be spaced apart from the bottom surface 31 by a predetermined distance.

(66) In some cases, where the heat conduction member 34 is made of a non-magnetic material having high thermal conductivity, the induced current generated based on the magnetic field may not be generated in the heat conduction member 34. Accordingly, based on the heat conduction member 34 having one end that contacts the bottom surface 31, the heat caused based on the induced current may not be generated in the heat conduction member 34 that contacts the bottom surface 31.

(67) In this case, the area where heat is generated based on the induced current is obtained by subtracting an area of one end of the heat conduction member 34 from an area of an entire bottom surface 31. For example, the heat conduction member 34 may have one end spaced apart from the bottom surface 31 by a predetermined distance.

(68) The heat conduction member 34 may have one end that is disposed in the heat conduction space HA and horizontally bent.

(69) In some examples, an outer surface of the heat conduction member 34 may be flush with an outer surface of the inner pot 30a.

(70) In some implementations, referring to FIG. 8B, the inner pot 30b may include a heat conduction member 34 and the heat conduction member 34 is disposed in the heat conduction space HA and extends along a depth direction of the inner pot 30b and has one end of the heat conduction member 34 horizontally curved. In this case, as shown in the side cross-sectional view of the inner pot 30b, the heat conduction member 34 may have an L-shape. For instance, the heat conduction member 34 may include (i) a first portion that extends along the outer surface of the inner pot and (ii) a second portion that is curved from a lower end of the first portion toward the inner surface of the inner pot 30b and that extends into the heat conduction space. In some examples, an outer surface of the first portion may be flush with an outer surface of the inner pot 30b.

(71) The heat conduction member 34 may be bent by 90 degrees, as shown in FIG. 8B, or alternatively, may be bent to have a curved shape.

(72) As described with reference to FIG. 8A, the heat conduction member 34 may have one end facing the bottom surface 31 may be spaced apart from the bottom surface 31 by a predetermined distance.

(73) FIG. 9 shows temperatures of inner pots 30, 30a, and 30b with respect to heights of the inner pots 30, 30a and 30b determined based on a lower portion of the inner pot 30 in FIG. 4A and lower portions of the inner pot 30a and 30b in FIGS. 8A and 8B heated with same power.

(74) Referring to FIG. 9, in the case of the inner pot 30 shown in FIG. 4A, the surface of the inner pot 30 has a temperature from a minimum of 224° C. to a maximum of 120° C., and in the case of the inner pot 30a shown in FIG. 8A, the surface of the inner pot 30a has a temperature from a minimum of 120° C. to a maximum of 206° C., and in the case of the inner pot 30b is shown in FIG. 8B, the surface of the inner pot 30 has a temperature of a minimum of 120° C. to a maximum of 200° C.

(75) The inner pots 30a and 30b including the heat conduction member 34 may improve the temperature distribution uniformity compared to the inner pot not including the heat conduction member 34. The inner pot 30b including an L-shaped heat conduction member 34 has improved temperature distribution uniformity compared to the inner pot 30a including the I-shaped heat conduction member 34.

(76) FIG. 10 shows a graph corresponding to a temperature (T) of the inner pot 30 in FIG. 4A, a temperature (Ta) of the inner pot 30a in FIG. 8A, and a temperature (Tb) of the inner pot 30b in FIG. 8B with respect to heights of inner pots 30, 30a, and 30b.

(77) Referring to FIG. 10, when temperatures of the inner pots are measured at a relatively low height of the inner pots, the inner pots 30a and 30b including the heat conduction member 34 have lower temperatures than the inner pot 30 not including the heat conduction member 34 (see a direction of arrow A). By contrast, when temperatures of the inner pot are measured at a relatively greater height of the inner pots, the inner pots 30a and 30b including the heat conduction member 34 have greater temperatures than the inner pot 30 not including the heat conduction member 34 (see a direction of arrow B). Accordingly, the overall temperature distribution uniformity is provided.

(78) In some cases, when the temperatures of the inner pots are measured at a relatively less height of the inner pots, the inner pot 30b including the L-shaped heat conduction member 34 has lower temperature of the inner pot 30b than the inner pot 30a including the I-shaped heat conduction member 34 (see a direction of arrow A). By contrast, when the temperatures of the inner pots measured at a relatively greater height of the inner pots, the inner pot 30b including the L-shaped heat conduction member 34 has greater temperature of the inner pot 30b than the inner pot 30a including the I-shaped heat conduction member 34 (see a direction of arrow B). Accordingly, the overall temperature distribution uniformity is provided.

(79) As described above, according to the present disclosure, the heat conduction efficiency may be further improved through the heat conduction member 34, thereby further improving the cooking quality through a very simple configuration, thereby improving productivity of the product.

(80) In some implementations, a metal plate configured to be heated based on the magnetic field generated by the heating coil H.C. may be disposed on the bottom surface 31 of the inner pot 30.

(81) In order to improve the heat conduction efficiency, the inner pot 30 may be made of a material having little or no magnetic properties (e.g., aluminum (Al), copper (Cu), and the like) and having high thermal conductivity. In this case, little or no induced current, which is generated based on the magnetic field, may be generated on the bottom surface 31 of the inner pot 30.

(82) In some implementations, even when the inner pot 30 has the greater thermal conductivity, as no heat is generated on the bottom surface 31 of the inner pot 30, the metal plate may be disposed on the bottom surface 31 of the inner pot 30 to generate the heat in the inner pot 30.

(83) The metal plate is made of a magnetic material, and may be attached to the bottom surface 31 of the inner pot 30 and may be coated on the bottom surface 31 of the inner pot 30 through a metal spraying process.

(84) Accordingly, based on the magnetic field generated by the heating coil H.C., heat may be generated in the metal plate based on the induced current, and the heat generated in the metal plate may be transferred to the inner pot 30.

(85) In some cases, where the inner pot 30 is made of a material having the greater thermal conductivity and being not magnetic, the heat conduction member 34 having the greater thermal conductivity than the thermal conductivity of the material of the inner pot 30 may be provided in the heat conduction space HA of the inner pot 30.

(86) Various substitutions, modifications, and changes may be made within the scope that does not deviate from the technical idea of the present disclosure for the skilled person in the art to which the present disclosure pertains, the above-mentioned disclosure is not limited to the above-mentioned implementation and the accompanying drawings.

(87) Other implementations are within the scope of the following claims.