A cooking appliance and an electromagnetic wire coil for a cooking appliance

Abstract

The utility model discloses a kind of electromagnetic wire disc and cooking utensil for cooking utensil, electromagnetic wire disc includes disc body and electromagnetic coil winding on the surface of disc body, disc body includes bottom wall and side wall, electromagnetic coil includes the first coil of being wound in bottom wall, and the second coil of being wound in side wall, the impedance of first coil is greater than the impedance of second coil, so that the output power of second coil is greater than first coil when first coil and second coil work simultaneously, wherein the length of first coil is less than the length of second coil. By adjusting the impedance of two groups of coils, the impedance of the second coil is less than the impedance of the first coil. When the two groups of coils work simultaneously, the heating power to the side of the pot is greater than the heating power to the bottom of the pot, so that the side of the pot has more heat, thereby improving the uniformity of the heat distribution of the side and the bottom, the total power can meet the heating demand, while ensuring the heating uniformity of each area of the pot.

Description

Technical Field

[0001] This utility model belongs to the field of kitchen appliance technology, specifically relating to an electromagnetic coil for cooking utensils and the cooking utensils themselves. Background Technology

[0002] In modern family life, the core heating technology of cooking appliances has evolved from traditional resistance heating to IH electromagnetic induction heating. IH heating technology uses electromagnetic induction to heat the cookware itself, which has advantages such as high thermal efficiency and fast heating speed compared to traditional resistance heating, and is therefore widely used in mid-to-high-end products.

[0003] Most electromagnetic cooking appliances currently on the market use a single-coil heating coil structure. A single coil typically heats mainly the bottom of the pot, concentrating the heat at the bottom and resulting in a slow upward transfer of heat. This leads to a significant temperature difference between the top and bottom of the food inside the pot, causing food near the bottom to be overheated while food near the top is underheated. Even products that use multiple coils, allowing the coils to heat the bottom and sides of the pot simultaneously, still suffer from problems such as the inability to flexibly adjust the power distribution between the multiple coils and the lack of independent heating control.

[0004] From the perspective of electromagnetic induction heating principles, the effectiveness of electromagnetic heating depends on the strength of the magnetic field generated by the coil and the degree of coupling between the coil and the cookware. According to Faraday's law of electromagnetic induction, the magnitude of the induced electromotive force is directly proportional to the rate of change of magnetic flux, which in turn is related to the number of turns, area, and magnetic field strength of the coil. In existing multi-coil structures, the heating power of the bottom coil and the side coils is often the same, making it difficult to accurately distribute the heat received by different areas of the cookware according to the heating needs of the food. This results in uneven heating of the food, with heat tending to accumulate at the bottom of the cookware, while the sides and top receive insufficient heat, affecting the taste and nutrient retention of the food. Utility Model Content

[0005] This invention provides an electromagnetic coil for cooking utensils and a cooking utensil to solve the problems of uneven heating and inflexible power distribution of multiple coils in existing electromagnetic heating coils, which leads to uneven heating of the bottom and sides of the pot.

[0006] The technical solution adopted in this utility model is as follows: An electromagnetic coil for a cooking appliance includes a plate body and an electromagnetic coil wound around the surface of the plate body. The plate body includes a bottom wall and a side wall. The electromagnetic coil includes a first coil wound on the bottom wall and a second coil wound on the side wall. The impedance of the first coil is greater than the impedance of the second coil, so that when the first coil and the second coil work simultaneously, the output power of the second coil is greater than that of the first coil.

[0007] In this invention, the bottom wall of the electromagnetic coil corresponds to the bottom of the upper pot, and the side wall corresponds to the arc-shaped transition section and / or side wall of the pot. This allows the first coil to primarily heat the bottom of the pot, and the second coil to primarily heat the sides of the pot when the electromagnetic coil is working. For electromagnetic coils, the smaller the impedance, the greater the current flowing through them under the same voltage, and thus the greater the power (power P = U). 2 / R, where U is voltage and R is impedance). By adjusting the impedance of the two sets of coils, the impedance of the second coil is made less than that of the first coil. When both sets of coils work simultaneously, the power of the first coil wound on the bottom wall is less than the power of the second coil wound on the side wall, thus achieving a reasonable power distribution between the two sets of coils. For example, with a rated voltage of 220V, the total power of the electromagnetic coil is 1400W. The power of the first coil can be controlled at 600W, and the power of the second coil can be controlled at 800W. This ensures that the heating power on the side of the pot is greater than the heating power on the bottom of the pot, giving the side of the pot more heat and improving the uniformity of heat distribution between the side and the bottom. The total power can meet the heating requirements while ensuring uniform heating in all areas of the pot.

[0008] An electromagnetic coil is formed by winding multiple strands of wire, with the number of strands in the first coil being less than that in the second coil.

[0009] In this scheme, both the first coil and the second coil are formed by winding multiple strands of wire. When the two use stranded wire of the same diameter, the number of strands they are wound is different. The number of strands of the first coil is less than the number of strands of the second coil, so that the wire diameter of the first coil is smaller than that of the second coil. In this way, the impedance of the first coil is greater than that of the second coil, and the heating power of the second coil is greater than that of the first coil.

[0010] The first and second coils are electrically connected to the control module so that they can work independently.

[0011] In this design, the first coil, when energized, forms a magnetic field at the bottom of the pot to heat the bottom. The second coil, when energized, forms a magnetic field at the side and curved transition section of the pot to heat the side. The first and second coils are wound independently and electrically connected to the control module, allowing them to work together or independently, achieving "dual drive" of the two sets of coils. This enables precise control of the convection pattern inside the pot, or allows multiple convection patterns to alternate, further improving heating uniformity.

[0012] The control module has a heating state that controls the alternating operation of the first coil and the second coil.

[0013] In this design, when the first coil is working, the temperature at the bottom of the pot is higher, with the highest temperature at the bottom center. Therefore, due to the temperature difference, the liquid at the bottom center flows upwards, the liquid at the top center flows outwards, and the liquid at the top edge flows towards the bottom of the pot, forming convection from the inside out. When the second coil is working, the temperature on the sides of the pot is higher, causing the hot liquid to flow upwards, from the top towards the center of the pot, then towards the bottom of the inner pot from the center, and outwards from the bottom, forming convection from the outside in. The alternating operation of the two coils allows the liquid inside the pot to undergo these two types of flow alternately, resulting in a more even distribution of heat throughout the pot.

[0014] The second coil covers a larger area on the surface of the disk than the first coil.

[0015] In this design, the second coil has a larger coverage area than the first coil. The increased coverage area results in a stronger magnetic field generated by the second coil, which in turn improves the heating effect on the side of the cookware. This causes the food on the outer side (closer to the side of the cookware, i.e., the edge of the cookware) to be at a higher temperature, while the food on the inner side (away from the side of the cookware, i.e., the center of the cookware) is at a lower temperature. This creates an effective temperature gradient between the inner and outer sides, promoting strong convection between the inner and outer food, significantly improving heating uniformity, and allowing for more complete release of nutrients from the food.

[0016] The sidewall includes an arc-shaped portion and a vertical wall. The second coil extends from the arc-shaped portion to the vertical wall. The second coil is wound as a double-layer coil structure on the surface of the arc-shaped portion and as a single-layer coil structure on the surface of the vertical wall.

[0017] In this design, the second coil is wound as a double-layer coil at the curved section. The magnetic fields of the two layers can be superimposed, resulting in a stronger magnetic field at the curved section. Food tends to concentrate there more easily, which can specifically improve the heating effect on the curved transition area of ​​the pot. This concentrates more heat at the junction of the bottom and sides of the pot. Since the second coil at the curved section is closer to the first coil on the bottom wall, the double-layer winding here can balance the magnetic field at the junction of the side and bottom magnetic fields, reducing magnetic field fluctuations. The vertical wall area, where there is less food, is heated by the independent magnetic field formed by the single-layer wound second coil. This makes the heat distribution more compatible with the distribution of food, improving the rationality of heat distribution and helping to save costs while ensuring heating efficiency.

[0018] The arc-shaped part is provided with a first pressure rib and a second pressure rib located between the first pressure rib and the disc body. The second coil is wound between the first pressure rib and the second pressure rib to form an outer coil, and wound between the second pressure rib and the disc body to form an inner coil. The first pressure rib and the second pressure rib are staggered vertically.

[0019] In this design, the first and second pressure ribs are staggered in the circumferential direction (left and right) of the disc body. This satisfies the winding positioning requirements of the inner and outer coils at the arc-shaped section, while isolating them to prevent short circuits between the two layers of coils. Simultaneously, the different positioning positions of the first and second pressure ribs increase the overall limiting area for the coils at the arc-shaped section, improving the coil's positioning effect. This ensures the neatness and stability of the coils during winding and use, reduces uneven magnetic field distribution caused by coil loosening or displacement, and improves the electromagnetic induction heating efficiency at the arc-shaped section.

[0020] The inner coil covers a larger area on the disk surface than the outer coil.

[0021] In this design, the inner and outer coils are each considered as current-carrying coils composed of countless current elements. The coverage area of ​​the inner coil is larger than that of the outer coil, resulting in a staggered distribution of the two layers. The magnetic induction intensity generated by each current element in space is synthesized according to the principle of vector superposition. The central coil of the inner coil is the region with the strongest magnetic induction intensity generated by the current element (heating ring), and the central coil of the outer coil is also the region with the strongest magnetic induction intensity generated by the current element (heating ring). They are partially staggered and partially overlapped in the height direction, causing the total heating ring to extend in the height direction. In the overlapping region, the magnetic induction intensity is the superposition of the magnetic induction induction intensity generated by each layer of coils, forming a strong magnetic field; in the staggered region, each layer of coil still has a portion of its own heating ring, thus maintaining a relatively strong magnetic induction intensity. At this point, the total heating ring area is the sum of the heating ring areas of the inner and outer coils minus the area of ​​the overlapping heating ring. Compared to a scheme where the two heating rings completely overlap, this significantly increases the total area of ​​the side heating rings, which is also the height of the side heating rings. This increases the heating area on the sides of the cookware, allowing a larger area of ​​the sides to be covered by the heating rings. This improves the uniformity of heating on the sides of the cookware, resulting in more even heating of food on the bottom and sides, and improving the taste of the cooked food. At the same time, the larger heating area allows for a reduction in heating power or heating time, helping to lower energy consumption.

[0022] This utility model also discloses a cooking appliance, including a pot body and an inner pot placed inside the pot body, and also includes the above-mentioned electromagnetic coil for cooking appliances. The electromagnetic coil is disposed inside the pot body and located below the inner pot. The inner pot has an arc-shaped transition section located between the bottom and the side. The projection portion of the side wall toward the inner pot is located in the arc-shaped transition section, and part of it is located on the side.

[0023] The distance between the first coil and the outer surface of the inner liner is L1, and the distance between the second coil and the outer surface of the inner liner is L2, where L1=L2.

[0024] In this design, the distance between the wire and the cookware directly affects the intensity of the electromagnetic induction; the closer the distance, the stronger the magnetic field, and the farther the distance, the weaker the magnetic field. In this invention, since the heating power of the second coil is already greater than that of the first coil by adjusting the wire diameters of the first and second coils, the distances between the first and second coils and the cookware are designed to be identical to avoid affecting the heating power design. This ensures that when the electromagnetic coil is working, the magnetic field strength and heating power at the bottom and sides are distributed in an ideal manner, ensuring uniform heating of all areas of the cookware. Attached Figure Description

[0025] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of an electromagnetic coil according to one embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the disc body according to one embodiment of the present invention; Figure 3 This is a cross-sectional view of an electromagnetic coil according to one embodiment of the present invention. Figure 4 for Figure 3 A magnified view of area A in the middle; Figure 5 This is a cross-sectional view of the electromagnetic coil and inner liner according to one embodiment of the present invention. Figure 6 This is a cross-sectional view of the electromagnetic coil and inner liner according to another embodiment of the present invention.

[0026] in: 1. Disc body; 11. Bottom wall; 12. Vertical wall; 13. Arc-shaped part; 14. First pressure rib; 15. Second pressure rib; 2. Electromagnetic coil; 21. First coil; 22. Second coil; 221. Inner coil; 222. Outer coil; 3. Inner liner. Detailed Implementation

[0027] To more clearly illustrate the overall concept of this utility model, a detailed description will be provided below with reference to the accompanying drawings.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0029] Furthermore, it should be understood in the description of this utility model that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0031] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "aspect," or "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0032] like Figure 1 As shown, an electromagnetic coil for a cooking appliance includes a plate body 1 and an electromagnetic coil 2 wound around the surface of the plate body 1. The plate body 1 includes a bottom wall 11 and a side wall. The electromagnetic coil 2 includes a first coil 21 wound around the bottom wall 11 and a second coil 22 wound around the side wall. The impedance of the first coil 21 is greater than the impedance of the second coil 22, so that when the first coil 21 and the second coil 22 work simultaneously, the output power of the second coil 22 is greater than that of the first coil 21.

[0033] Specifically, such as Figure 3 As shown, the plate body 1 of this utility model has a bowl-shaped structure, which can simultaneously correspond to the bottom and sides of the pot above.

[0034] In this invention, the bottom wall 11 of the electromagnetic coil corresponds to the bottom of the upper pot, and the side wall corresponds to the arc-shaped transition section and / or side wall of the pot. This allows the first coil 21 to heat the bottom of the pot and the second coil 22 to heat the sides of the pot when the electromagnetic coil is working. For the electromagnetic coil 2, the smaller the impedance, the greater the current passing through it under the same voltage, and thus the greater the power (power P = U). 2 / R, where U is voltage and R is impedance). By adjusting the impedance of the two sets of coils, the impedance of the second coil 22 is made less than that of the first coil 21. When both sets of coils work simultaneously, the power of the first coil 21 wound on the bottom wall 11 is less than the power of the second coil 22 wound on the side wall, thus achieving a reasonable power distribution between the two sets of coils. For example, with a rated voltage of 220V, the total power of the electromagnetic coil is 1400W, the power of the first coil 21 can be controlled at 600W, and the power of the second coil 22 can be controlled at 800W. This makes the heating power on the side of the pot greater than the heating power on the bottom of the pot, giving the side of the pot more heat, thereby improving the uniformity of heat distribution on the side and bottom. The total power can meet the heating requirements while ensuring the uniformity of heating in all areas of the pot.

[0035] It should be noted that this invention does not limit the method of impedance adjustment for the first coil 21 and the second coil 22. Specifically, the wire diameters of the first coil 21 and the second coil 22 can be adjusted to make them different, or the materials of the first coil 21 and the second coil 22 can be adjusted, such as aluminum wire or copper wire commonly used in this field. Alternatively, the lengths of the first coil 21 and the second coil 22 can also be adjusted.

[0036] Preferably, the electromagnetic coil is formed by winding multiple strands of wire, and the number of strands in the first coil 21 is less than the number of strands in the second coil 22.

[0037] Both the first coil 21 and the second coil 22 are formed by winding multiple strands of wire. When the two use stranded wire of the same diameter, the number of strands they are wound is different. The number of strands in the first coil 21 is less than the number of strands in the second coil 22, so that the wire diameter of the first coil 21 is smaller than that of the second coil 22. Through this wire diameter difference design, the impedance of the first coil 21 is greater than that of the second coil 22, and the heating power of the second coil 22 is greater than that of the first coil 21.

[0038] It is understood that both the first coil 21 and the second coil 22 are wound from a single enameled wire. In this invention, the wire diameter of the first coil 21 and the second coil 22 refers to the diameter of a single enameled wire.

[0039] Specifically, in one embodiment, both the first coil 21 and the second coil 22 are made of enameled wire wound with a diameter of 0.1-0.3 mm, wherein the first coil 21 is wound with 50-70 strands of wire, and the second coil 22 is wound with 70-90 strands of wire.

[0040] As a preferred embodiment of this utility model, such as Figure 1 As shown, the first coil 21 and the second coil 22 are electrically connected to the control module.

[0041] When the first coil 21 is energized, it forms a magnetic field at the bottom of the pot to heat the bottom of the pot. When the second coil 22 is energized, it forms a magnetic field at the side of the pot and the arc-shaped transition section to heat the side of the pot.

[0042] The increased heating power of the second coil 22 not only creates an effective temperature gradient in the vertical direction, but also creates an effective temperature gradient between the food inside the pot and the surrounding area. This helps to promote the formation of convection in the liquid inside the pot, including the vertical and horizontal directions as well as the internal and external directions. This allows the food in each area of ​​the pot to move up and down and inside and outside in a more uniform way according to the convection. During this process, the food rolls and moves 360° without dead angles on the inside and outside and the top and bottom sides of the pot, making the heat distribution inside the pot more uniform, improving the heating uniformity and the taste of the cooked food.

[0043] In addition, the first coil 21 and the second coil 22 are wound independently and electrically connected to the control module, so that the first coil 21 and the second coil 22 can work together or work independently, realizing the "dual drive" of the two sets of coils, that is, the two sets of coils can be driven independently. This further enables precise control of the convection mode inside the pot, or allows multiple convection modes to be alternated to further improve the heating uniformity.

[0044] Specifically, during the heating process, the first coil 21 or the second coil 22 can be controlled individually, or both coils can be controlled to heat simultaneously, depending on the heating requirements of the ingredients. For example, in the initial stage of cooking rice, to quickly raise the temperature of the ingredients at the bottom of the pot, the first coil 21 can be controlled to heat at high power. Once the temperature of the bottom ingredients reaches a certain level, the second coil 22 can be controlled to start heating, heating the side walls and the top ingredients, while the power of the first coil 21 is appropriately reduced to avoid overheating the bottom ingredients. During the heat preservation stage, one or both coils can be selectively controlled to heat intermittently at low power, depending on the overall temperature of the ingredients in the pot, to maintain the temperature and texture of the ingredients.

[0045] Furthermore, the control module has a heating state that controls the alternating operation of the first coil 21 and the second coil 22.

[0046] like Figure 5 As shown, when the first coil 21 is working, the temperature at the bottom of the pot is higher, and the temperature at the center of the bottom is the highest. Therefore, under the influence of temperature difference, the liquid at the center of the bottom will flow upward, the liquid at the center of the top will flow outward, and the liquid at the top edge will flow towards the bottom of the pot, forming convection from the inside out. Figure 6 As shown, when the second coil 22 is working, the temperature on the side of the pot is higher, and the hot liquid will flow upward, from the top to the center of the pot, and then from the center of the pot to the bottom of the inner pot 3, and from the bottom to the surrounding areas, forming convection from the outside to the inside. The two sets of coils work alternately, which allows the liquid inside the pot to alternate between the above two flows, making the heat distribution in all areas of the pot more uniform.

[0047] Preferably, such as Figure 1 As shown, the coverage area of ​​the second coil 22 on the surface of the disk 1 is greater than the coverage area of ​​the first coil 21 on the surface of the disk 1.

[0048] The second coil 22 has a larger coverage area than the first coil 21. The increased coverage area results in a stronger magnetic field formed by the second coil 22, which in turn improves the heating effect on the side of the cookware. This causes the food on the outer side (closer to the side of the cookware, i.e., the edge of the cookware) to be at a higher temperature, while the food on the inner side (away from the side of the cookware, i.e., the center of the cookware) is at a lower temperature. This creates an effective temperature gradient between the inner and outer sides, promoting strong convection between the inner and outer food, significantly improving the uniformity of heating, and allowing for more complete release of nutrients from the food.

[0049] It should be noted that this invention does not limit the winding shape of the first coil 21 and the second coil 22; both can be wound into a circle or into a polygon. Alternatively, multiple winding areas can be provided at circumferential intervals on the sidewall, and the second coil 22 can be wound in each of these winding areas.

[0050] In a preferred embodiment, such as Figure 3 As shown, the sidewall includes an arc-shaped portion 13 and a vertical wall 12. The second coil 22 extends from the arc-shaped portion 13 to the vertical wall 12. The second coil 22 is wound as a double-layer coil structure on the surface of the arc-shaped portion 13 and as a single-layer coil structure on the surface of the vertical wall 12.

[0051] The second coil 22 is wound as a double-layer coil at the arc-shaped section 13. The magnetic fields of the two layers of coils can be superimposed, resulting in a stronger magnetic field at the arc-shaped section 13. Food tends to concentrate closer to the bottom, which can specifically improve the heating effect on the arc-shaped transition area of ​​the pot. This concentrates more heat at the junction of the bottom and sides of the pot. Since the second coil 22 at the arc-shaped section 13 is closer to the first coil 21 on the bottom wall 11, the double-layer winding here can balance the magnetic field at the junction of the side and bottom magnetic fields, reducing magnetic field fluctuations. The vertical wall 12, corresponding to the less food in the pot, is heated by the independent magnetic field formed by the single-layer winding of the second coil 22. This makes the heat distribution more compatible with the distribution of food, improving the rationality of heat distribution and helping to save costs while ensuring heating efficiency.

[0052] Furthermore, such as Figure 2 As shown, the arc-shaped portion 13 is provided with a first pressure rib 14 and a second pressure rib 15 located between the first pressure rib 14 and the disc body 1. The second coil 22 is wound between the first pressure rib 14 and the second pressure rib 15 to form an outer coil 222, and wound between the second pressure rib 15 and the disc body 1 to form an inner coil 221. The first pressure rib 14 and the second pressure rib 15 are staggered vertically.

[0053] The first pressure rib 14 and the second pressure rib 15 are offset in the circumferential direction (left and right) of the disc body 1. This satisfies the winding positioning requirements of the inner coil 221 and the outer coil 222 at the arc-shaped section 13, while isolating the inner coil 221 and the outer coil 222 to prevent short circuits between the two layers of coils. Simultaneously, the different limiting positions of the first pressure rib 14 and the second pressure rib 15 increase the overall limiting area of ​​the coil at the arc-shaped section 13, improving the limiting effect. This ensures the neatness and stability of the coil during winding and use, reduces uneven magnetic field distribution caused by coil loosening or displacement, and improves the electromagnetic induction heating efficiency at the arc-shaped section 13.

[0054] Furthermore, such as Figure 3 , Figure 4 As shown, the inner coil 221 covers a larger area on the surface of the disk 1 than the outer coil 222 covers.

[0055] The inner coil 221 and the outer coil 222 can be considered as current-carrying coils composed of countless current elements. The coverage area of ​​the inner coil 221 is larger than that of the outer coil 222, causing the two layers of coils to be staggered. The magnetic induction intensity generated by each current element in space is synthesized according to the principle of vector superposition. The central loop of the inner coil 221 is the region with a relatively strong magnetic induction intensity (heating ring) generated by the current element, and the central loop of the outer coil 222 is also the region with a relatively strong magnetic induction intensity (heating ring). They are partially staggered and partially overlapped in the height direction, causing the total heating ring to extend in the height direction. In the overlapping region, the magnetic induction intensity is the superposition of the magnetic induction induction intensity generated by each layer of coils, forming a strong magnetic field; in the staggered region, each layer of coil still has a portion of its own heating ring, thus maintaining a relatively strong magnetic induction intensity. At this point, the total heating ring area is the sum of the heating ring areas of the inner and outer coils minus the area of ​​the overlapping heating ring. Compared to a scheme where the two heating rings completely overlap, this significantly increases the total area of ​​the side heating rings, which is also the height of the side heating rings. This increases the heating area on the sides of the cookware, allowing a larger area of ​​the sides to be covered by the heating rings. This improves the uniformity of heating on the sides of the cookware, resulting in more even heating of food on the bottom and sides, and improving the taste of the cooked food. At the same time, the larger heating area allows for a reduction in heating power or heating time, helping to lower energy consumption.

[0056] Preferably, such as Figure 4 As shown, the inner coil of the inner coil 221 is flush with the inner coil of the outer coil 222, and the outer coil of the inner coil 221 is higher than the outer coil of the outer coil 222.

[0057] The inner coils of the inner coil 221 and the outer coil 222 are flush, creating an overlapping heating zone near the center of the pan 1. At the end furthest from the center, only the inner coil 221 covers this zone, creating an isolated heating zone. This results in a misalignment between the heating rings formed by the inner coil 221 and the outer coil 222, with the inner coil 221 being taller and closer to the top than the outer coil 222, effectively increasing the width of the side heating ring. Furthermore, food tends to accumulate closer to the bottom; therefore, the overlapping heating zone formed by the flush inner coils of the inner and outer coils allows their magnetic fields to superimpose, specifically enhancing the heating effect on the bottom side of the cookware. This concentrates more heat at the intersection of the bottom and side of the cookware, while the area above the side is heated by the independent magnetic field of the inner coil 221. This results in a more optimized heat distribution that better matches the distribution of food, improving the overall heat distribution efficiency.

[0058] Preferably, the first coil 211 is also wound in a double-layer structure on the bottom wall 11, and the outer coil of the inner coil is located outside the outer coil of the outer coil.

[0059] This utility model also discloses a cooking appliance, including a pot body and an inner pot 3 placed inside the pot body, and also includes the above-mentioned electromagnetic coil for cooking appliances. The electromagnetic coil is disposed inside the pot body and below the inner pot 3. The inner pot 3 has an arc-shaped transition section between the bottom and the side, and at least a portion of the projection of the side wall toward the inner pot 3 is located in the arc-shaped transition section.

[0060] Specifically, the sidewall includes an arc-shaped portion 12 and a vertical wall. The projection of the arc-shaped portion 13 can completely correspond to the arc-shaped transition section, or it can be partially located in the arc-shaped transition section and partially located in the side of the inner liner 3.

[0061] Preferably, the distance between the first coil 21 and the outer surface of the inner liner 3 is L1, and the distance between the second coil 22 and the outer surface of the inner liner 3 is L2, where L1=L2.

[0062] The distance between the conductor 2 and the cookware directly affects the intensity of electromagnetic induction; the closer the distance, the stronger the magnetic field, and the farther the distance, the weaker the magnetic field. In this invention, since the heating power of the second coil 22 is greater than that of the first coil 21 by adjusting the wire diameters of the first coil 21 and the second coil 22, the distances between the first coil 21, the second coil 22, and the cookware are designed to be the same to avoid affecting the heating power design. This ensures that when the electromagnetic coil is working, the magnetic field strength and heating power at the bottom and sides can be distributed in an ideal manner, ensuring uniform heating of all areas of the cookware.

[0063] Specifically, the bottom wall 11 of the disc body 1 has a planar area, and the first coil 21 is wound in a flat or concave shape within this planar area, mainly corresponding to the bottom area of ​​the inner liner 3. The first coil 21 is wound on an independent coil frame, which is a flat or concave structure (adapted to the winding shape of the first coil 21) to ensure a uniform distance between the first coil 21 and the bottom of the inner liner 3. Preferably, the distance between the first coil 21 and the bottom of the inner liner 3 is controlled within the range of 9-14mm to ensure heating efficiency.

[0064] The second coil 22 is wound on a separate coil frame, the shape of which is adapted to the contour of the arc-shaped portion 13 and part of the vertical wall 12, ensuring a suitable distance between the second coil 22 and the inner liner 3 to guarantee good electromagnetic coupling. Preferably, the distance between the second coil 221 and the inner liner 3 is also controlled within the range of 9-14mm, which can ensure high thermal efficiency while avoiding problems such as melting of the contact surface between the inner liner 3 and the coil due to excessive distance or excessive magnetic flux loss due to excessive distance.

[0065] For any parts not mentioned in this utility model, existing technologies can be used or referenced.

[0066] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0067] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. An electromagnetic coil for a cooking utensil, comprising a coil body and an electromagnetic coil wound around the surface of the coil body, characterized in that, The disk body includes a bottom wall and a side wall. The electromagnetic coil includes a first coil wound on the bottom wall and a second coil wound on the side wall. The impedance of the first coil is greater than the impedance of the second coil, so that when the first coil and the second coil work simultaneously, the output power of the second coil is greater than that of the first coil.

2. The electromagnetic coil for cooking appliances according to claim 1, characterized in that, The electromagnetic coil is formed by winding multiple strands of wire, and the number of strands in the first coil is less than the number of strands in the second coil.

3. The electromagnetic coil for cooking appliances according to claim 1, characterized in that, The first coil and the second coil are electrically connected to the control module so that they can work independently.

4. The electromagnetic coil for cooking appliances according to claim 3, characterized in that, The control module has a heating state that controls the first coil and the second coil to work alternately.

5. The electromagnetic coil for cooking appliances according to claim 1, characterized in that, The second coil covers a larger area on the surface of the disk than the first coil covers on the surface of the disk.

6. The electromagnetic coil for cooking appliances according to claim 1, characterized in that, The sidewall includes an arc-shaped portion and a vertical wall. The second coil extends from the arc-shaped portion to the vertical wall. The second coil is wound as a double-layer coil structure on the surface of the arc-shaped portion and as a single-layer coil structure on the surface of the vertical wall.

7. The electromagnetic coil for cooking appliances according to claim 6, characterized in that, The arc-shaped portion is provided with a first pressure rib and a second pressure rib located between the first pressure rib and the disc body. The second coil is wound between the first pressure rib and the second pressure rib to form an outer coil, and wound between the second pressure rib and the disc body to form an inner coil. The first pressure rib and the second pressure rib are staggered vertically.

8. The electromagnetic coil for cooking appliances according to claim 7, characterized in that, The inner coil has a larger coverage area on the disk surface than the outer coil has.

9. A cooking utensil, comprising a pot body and an inner pot disposed inside the pot body, characterized in that, It also includes the electromagnetic coil for cooking appliances according to any one of claims 1-8, the electromagnetic coil being disposed inside the pot body and below the inner pot, the inner pot having an arcuate transition section between the bottom and the side, and the projection of the side wall toward the inner pot being at least partially located in the arcuate transition section.

10. The cooking utensil according to claim 9, characterized in that, The distance between the first coil and the outer surface of the inner liner is L1, and the distance between the second coil and the outer surface of the inner liner is L2, where L1=L2.

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