IH electric cooker uniform in heating

By using a flat coil combined with a concave inner pot design in an IH rice cooker, the problem of uneven heating of the inner pot is solved, resulting in more uniform heating and reduced costs.

CN223640515UActive Publication Date: 2025-12-09钟石刚 +1
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Patent Information

Application Number
CN202321464008.4
Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
Priority Date
2022-09-29
Filing Date
2023-06-08
Publication Date
2025-12-09
Estimated Expiration
2033-06-08

AI Technical Summary

Technical Problem

When using a flat coil, existing IH rice cookers result in uneven heating of the inner pot, and the concave coil is more expensive and has low production efficiency.

Method used

The design employs a planar coil combined with a concave bottom of the inner pot, resulting in a larger distance between the bottom of the inner pot and the coil in the middle and a smaller distance at the periphery. This matches the density distribution of the magnetic field, reducing the difference in heating power at the bottom of the inner pot. The height difference design between the concave part and the support part ensures a uniform distribution of the magnetic field.

Benefits of technology

This results in more uniform heating of the inner pot, reduces product costs, and improves the boiling effect and tumbling performance when heating fluid media.

✦ Generated by Eureka AI based on patent content.

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Abstract

The IH electric cooker comprises an outer shell and an inner pot, a concave cavity used for containing the inner pot is formed in the outer shell, and a plane coil panel is arranged at the bottom of the inner side of the concave cavity; the inner pot is placed on the planar coil panel; the bottom of the inner pot is sunken upwards to form an inner concave part, and a supporting part is arranged on the periphery of the inner concave part. The inner pot is provided with the concave part, and the height difference parameter of the concave part and the supporting part is set, so that the distance between the surface of the planar coil panel and the bottom surface of the inner pot is large in the middle and small in the periphery, the difference of the heating power of the pot bottom is reduced, the heating uniformity is better, the boiling is more uniform when a fluid medium is heated, and the overall rolling effect is obviously improved; and the area of the pot bottom is also increased by arranging the concave part, so that the energy efficiency is further improved.
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Description

Technical Field

[0001] This utility model relates to a cooking appliance, and more particularly to an IH rice cooker that heats evenly. Background Technology

[0002] With the development of technology, electromagnetic heating is becoming increasingly common. Its high heating efficiency, lack of open flame, energy saving, and safety have led to its widespread application. Currently, there are two types of IH rice cookers: one with a flat coil and a flat-bottomed inner pot (the bottom of the inner pot is flat), and the other with a concave coil and a round-bottomed inner pot (the bottom of the inner pot is curved).

[0003] Electromagnetic heating involves a coil generating a high-frequency magnetic field. This high-frequency magnetic field passes through an iron inner pot, creating resistance and generating heat. With a flat-bottomed inner pot and a concave-bottomed inner pot, the distance between the bottom of the inner pot and the top surface of the coil winding is roughly the same. However, the magnetic field lines of the high-frequency magnetic field tend to converge, resulting in a denser magnetic field distribution in the center of the coil compared to the outer edge, leading to uneven heating of the inner pot. Furthermore, using a concave coil is more expensive and less efficient than using a flat coil. Therefore, a rice cooker capable of achieving uniform heating using a flat coil is needed. Utility Model Content

[0004] In view of the shortcomings of the existing technology, this utility model proposes an IH rice cooker with uniform heating, which can make the inner pot heat evenly and reduce product costs.

[0005] The technical solution of this utility model is implemented as follows:

[0006] An IH rice cooker with uniform heating includes an outer shell and an inner pot. A cavity for placing the inner pot is formed in the outer shell, and a flat coil is provided on the bottom inner side of the cavity. The inner pot is placed on the flat coil, and the bottom of the inner pot is concave upward to form a concave portion. The periphery of the concave portion is a support portion.

[0007] In one embodiment, the height difference between the highest point of the concave portion and the lowest point of the support portion is the concave height, which is 10-20 mm.

[0008] In one embodiment, the concave portion is an arc-shaped surface, and a first flat portion is provided at the center of the concave portion.

[0009] In one embodiment, the support portion is provided with a first planar ring portion.

[0010] In one embodiment, the concave portion includes a central arcuate portion and an arcuate ring located around the central arcuate portion. The inner edge of the arcuate ring is connected to the central arcuate portion, and the outer edge of the arcuate ring is connected to the support portion.

[0011] In one embodiment, the support portion is provided with a second planar ring portion.

[0012] In one embodiment, a second planar portion is provided at the center of the central arc-shaped portion.

[0013] In one embodiment, a temperature sensor is disposed at the center of the planar coil disk, which contacts the center of the recess, and the center of the recess is adapted to the top shape of the temperature sensor.

[0014] In one embodiment, the concave portion and the supporting portion form an arc-shaped transition.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] This invention reduces the cost of IH rice cookers by setting up a planar coil. By creating a concave portion on the inner pot, the distance between the surface of the planar coil and the bottom of the inner pot tends to be larger in the middle and smaller at the periphery. This matches the density of the magnetic field generated by the planar coil. In the middle of the coil where the magnetic field is concentrated, the distance between the bottom of the inner pot and the planar coil is increased, while in the periphery where the magnetic field is sparse, the distance between the bottom of the inner pot and the planar coil is decreased. This reduces the difference in heating power at the bottom of the inner pot, resulting in more uniform heating. When heating fluid media, the internal boiling is more uniform, and the overall tumbling effect is significantly improved. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of an IH rice cooker with uniform heating according to this utility model;

[0019] Figure 2 A cross-sectional view of an IH rice cooker with uniform heating according to this utility model.

[0020] Figure 3 This is a cross-sectional view of the inner pot and the planar coil plate in Embodiment 1 of this utility model;

[0021] Figure 4 This is a cross-sectional view of the inner pot in Embodiment 2 of this utility model;

[0022] Figure 5 This is a cross-sectional view of the inner pot in Embodiment 3 of this utility model;

[0023] Figure 6This is a cross-sectional view of the inner pot in Embodiment 4 of this utility model;

[0024] Figure 7 This is a cross-sectional view of the inner pot in Embodiment 5 of this utility model;

[0025] Figure 8 This is a cross-sectional view of the inner pot in Embodiment Six of this utility model;

[0026] Figure 9 This is a cross-sectional view of the inner pot in Embodiment 7 of this utility model;

[0027] Figure 10 This is a diagram showing the magnetic field state during heating in an IH rice cooker that provides uniform heating, according to this utility model.

[0028] Reference numerals in the attached figures: 1-Inner pot; 2-Concave portion; 3-Support portion; 4-First flat portion; 5-First flat ring portion; 6-Central arc portion; 7-Arc ring; 8-Second flat ring portion; 9-Second flat portion; 10-Temperature sensor; 11-Outer shell; 12-Concave cavity; 13-Planar coil disc. Specific Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for 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. Furthermore, the terms "first," "second," "third," and "fourth," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0031] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0032] This invention reduces the cost of an IH rice cooker by incorporating a planar coil. The recessed portion on the inner pot creates a wider distance between the surface of the planar coil and the bottom of the inner pot, decreasing towards the periphery. This design matches the density of the magnetic field generated by the coil. The increased distance between the inner pot bottom and the coil in the center, where the magnetic field is concentrated, and the decreased distance at the periphery, where the magnetic field is less dense, reduces the uneven heating of the inner pot bottom, resulting in more uniform heating. When heating fluids, this leads to more even boiling and significantly improved overall tumbling. A detailed description follows.

[0033] Example 1

[0034] See Figures 1 to 3 This utility model discloses an IH rice cooker with uniform heating, including an outer shell 11 and an inner pot 1. A cavity 12 is formed in the outer shell 11 for placing the inner pot 1, and a flat coil 13 is provided on the bottom inner side of the cavity 12. The inner pot 1 is placed on the flat coil 13. The bottom of the inner pot 1 is concave upwards to form a concave portion 2, and a support portion 3 surrounds the concave portion 2. Specifically, the height difference between the highest point of the concave portion 2 and the lowest point of the support portion 3 is the concave height h1, which is 10-20 mm. Due to the height difference between the concave portion 2 and the support portion 3, and the fact that the concave portion 2 is an arc-shaped surface, the magnetic field density passing through all parts of the bottom of the inner pot 1 is the same, thereby ensuring that the electromagnetic heating degree is consistent throughout the bottom of the inner pot 1, achieving a uniform heating effect. It is understood that the combination of the inner pot 1 and the flat coil 13 is actually an electromagnetic heating structure; therefore, this utility model can be applied to various electromagnetic heating cooking appliances, such as rice cookers and induction cookers, and should be within the protection scope of this utility model. In a preferred embodiment, the maximum diameter d2 of the support portion 3 is 0-30 mm larger than the maximum diameter d1 of the winding of the planar coil 13. This ensures that the heating effect is the same at different positions on the bottom of the inner pot 1 from the center outwards. The concave portion 2 and the support portion 3 have an arc-shaped transition. This allows for more precise changes in the distance between the bottom of the inner pot 1 and the planar coil 13, matching magnetic fields of different densities. This further improves the uniformity of heating while also ensuring the inner pot 1 has a beautiful and smooth shape, enhancing the user experience.

[0035] like Figure 2 As shown, a temperature sensor 10 is disposed at the center of the planar coil 13, contacting the center of the recess 2. The center of the recess 2 is adapted to the top shape of the temperature sensor 10. The temperature sensor 10 monitors the heating temperature of the inner pot 1 in real time, ensuring that the controller can adjust the temperature inside the inner pot 1 in real time during cooking. It is understood that, in practice, the temperature sensor 10 can also be removed, allowing the planar coil 13 to have a larger winding area and generate a stronger magnetic field to improve heating efficiency.

[0036] Figure 10 This utility model discloses a magnetic field state diagram of an IH rice cooker with uniform heating during heating. It can be seen that when the inner pot 1 is heated, the magnetic field strength at the bottom of the inner pot 1 is characterized by being denser in the middle and sparser on the outer side. Therefore, this application provides a concave part on the inner pot, and the distance between the surface of the planar coil 13 and the bottom surface of the inner pot 1 tends to be larger in the middle and smaller on the outer side, so as to match the density of the magnetic field generated by the planar coil 13. In the middle of the planar coil 13 where the magnetic field is concentrated, the distance between the bottom of the inner pot 1 and the planar coil 13 is increased, and in the outer side where the magnetic field is relatively sparse, the distance between the bottom of the inner pot 1 and the planar coil 13 is decreased, thereby reducing the difference in heating power at the bottom of the inner pot 1 and making the heating effect more uniform.

[0037] Example 2

[0038] like Figure 4 As shown, the difference between this embodiment and Embodiment 1 is that a first flat portion 4 is provided at the center of the concave portion 2.

[0039] Example 3

[0040] like Figure 5 As shown, the difference between this embodiment and Embodiment 1 is that the support part 3 is provided with a first planar ring part 5.

[0041] Example 4

[0042] like Figure 6 As shown, the difference between this embodiment and Embodiment 1 is that the concave portion 2 includes a central arc-shaped portion 6 and an arc-shaped ring 7 located around the central arc-shaped portion 6. The inner edge of the arc-shaped ring 7 is connected to the central arc-shaped portion 6, and the outer edge of the arc-shaped ring 7 is connected to the support portion 3.

[0043] Example 5

[0044] like Figure 7 As shown, the difference between this embodiment and embodiment four is that the support part 3 is provided with a second planar ring part 8.

[0045] Example 6

[0046] like Figure 8 As shown, the difference between this embodiment and embodiment four is that a second flat portion 9 is provided at the center of the central arc-shaped portion 6.

[0047] Example 7

[0048] like Figure 9 As shown, the difference between this embodiment and embodiment five is that a second flat portion 9 is provided at the center of the central arc-shaped portion 6.

[0049] It is understood that the purpose of the above embodiments is to make the distance between the center of the bottom of the inner pot 1 and the planar coil 13 greater than the distance between the outer support part 3 and the planar coil 13, thereby achieving the effect of uniform heating using the planar coil 13. Similar structures should be within the protection scope of this application.

[0050] This application creates a recessed portion 2 on the inner pot 1, and the distance between the surface of the planar coil disk 13 and the bottom surface of the inner pot 1 tends to be larger in the middle and smaller at the periphery. This matches the density of the magnetic field generated by the planar coil disk 13. In the middle of the coil disk where the magnetic field is concentrated, the distance between the bottom of the inner pot 1 and the planar coil disk 13 is increased, while in the periphery where the magnetic field is sparse, the distance between the bottom of the inner pot 1 and the planar coil disk 13 is decreased. This makes the electromagnetic heating generated by the magnetic field at different locations the same, reduces the difference in heating power at the bottom of the inner pot, and makes the heating effect more uniform. When heating the fluid medium, the internal boiling is more uniform, and the overall tumbling effect is significantly improved.

[0051] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A uniformly heated IH rice cooker, comprising an outer shell (11) and an inner pot (1), wherein a cavity (12) for placing the inner pot (1) is formed in the outer shell (11), characterized in that: The inner bottom of the cavity (12) is provided with a flat coil disk (13); the inner pot (1) is placed on the flat coil disk (13); The bottom of the inner pot (1) is concave upward to form a concave part (2), and the periphery of the concave part (2) is a support part (3); The maximum diameter d2 of the support part (3) is 0-30 mm larger than the maximum diameter d1 of the winding of the planar coil disk (13); The distance between the center of the bottom of the inner pot (1) and the flat coil plate (13) is greater than the distance between the outer support part (3) and the flat coil plate (13); The inner pot (1) is provided with a concave part (2), and the distance between the surface of the flat coil (13) and the bottom surface of the inner pot (1) shows a trend of being larger in the middle and smaller at the periphery.

2. The uniformly heated IH rice cooker according to claim 1, characterized in that, The height difference between the highest point of the concave portion (2) and the lowest point of the support portion (3) is the concave height, which is 10-20 mm.

3. The uniformly heated IH rice cooker according to claim 1, characterized in that, The concave portion (2) is an arc-shaped surface, and a first flat portion (4) is provided at the center of the concave portion (2).

4. The uniformly heated IH rice cooker according to claim 1, characterized in that, The support part (3) is provided with a first planar ring part (5).

5. The uniformly heated IH rice cooker according to claim 1, characterized in that, The recessed portion (2) includes a central arc-shaped portion (6) and an arc-shaped ring (7) located around the central arc-shaped portion (6). The inner edge of the arc-shaped ring (7) is connected to the central arc-shaped portion (6), and the outer edge of the arc-shaped ring (7) is connected to the support portion (3).

6. The uniformly heated IH rice cooker according to claim 5, characterized in that, The support part (3) is provided with a second planar ring part (8).

7. The uniformly heated IH rice cooker according to claim 5 or 6, characterized in that, The center of the central arc-shaped portion (6) is provided with a second flat portion (9).

8. The uniformly heated IH rice cooker according to claim 1, characterized in that, A temperature sensor (10) is disposed at the center of the planar coil disk (13) and contacts the center of the recess (2), wherein the center of the recess (2) is adapted to the top shape of the temperature sensor (10).

9. The uniformly heated IH rice cooker according to claim 1, characterized in that, The concave portion (2) and the supporting portion (3) have an arc-shaped transition.