Air fryer with IH coil heating plate at bottom

Abstract

The utility model relates to an air fryer with a bottom IH coil heating plate, and aims to solve the technical problems that the existing similar air fryer with upper and lower heating pipes is poorer in bottom heating temperature stability and more difficult to control, and meanwhile, the steam heating structural design and the inner pot placement induction detection structural design are too complicated and the production cost is high. The air fryer is characterized in that an IH coil heating plate is arranged at a metal heat insulation layer at the bottom of the lower portion of an inner pot of the air fryer, a grill is arranged in the inner pot, the inner pot is a non-magnetic pot body or a ferrite pot body, and the grill is a ferrite grill; the baking tray is aligned with the IH coil heating tray below, and the grill in the inner pot is heated by the magnetic induction of the IH coil heating tray through the inner pot; when the inner pot is a non-magnetic pot body, a glass layer is arranged at the hollow part in the middle of the inner bottom of the inner pot; meanwhile, the IH coil heating disc serves as a microswitch, and whether the inner pot of ferrite is placed or not is sensed through the magnetic field generated by the IH electromagnetic module before use.

Description

Technical Field

[0001] The utility model relates to an air fryer, in particular to an air fryer with an IH coil heating plate at the bottom. Background Art

[0002] An air fryer is a new household appliance that uses high-speed air circulation technology to fry food. It produces food with 80% less oil than traditional electric fryers, is easy to clean, and is both safe and economical, making it highly popular. Some existing air fryers have upper and lower heating tubes on the inner pot, such as the utility model "Air Fryer Bottom Heating Structure" described in Chinese patent application number 202320435577.X, published on September 26, 2023. Other similar products utilize the operating principle of an air fryer for pizza cooking, replacing the lower heating tube at the bottom of the inner pot with an electromagnetic heating module and its associated heating plate. For example, the utility model "An Electromagnetic Heating Pizza Maker and Its Control Method" is described in Chinese patent application number 202410422595.3, published on July 16, 2024. IH heating utilizes the principle of electromagnetic induction for heating, characterized by high efficiency, uniformity, and safety. IH heating operates by generating a magnetic field through electromagnetic coils, causing the inner pot to generate heat directly, thus avoiding the heat conduction losses associated with traditional heating methods. The heat conversion rate is extremely high, reaching over 95%. The aforementioned air fryers with upper and lower heating tubes utilize radiant heating methods, such as bottom heating using multiple electric heating tubes. Since the grill is typically located within the inner pot, the heat conduction efficiency of the electric heating tubes is relatively low. Furthermore, high temperatures generate a significant amount of excess heat, causing an excessive temperature rise in the entire machine. Heat-resistant materials are also required in certain areas, increasing costs. Other air fryers with steam functions, however, require complex enclosed structures for safety reasons, resulting in higher costs. Furthermore, most air fryers currently on the market use a machine switch to control the opening and closing of the heating tubes, making installation and costly. Summary of the Invention

[0003] To overcome the aforementioned shortcomings, the present invention aims to provide an air fryer with a bottom-mounted IH coil heating plate. This air fryer addresses the technical issues of existing similar air fryers with upper and lower dual heating tubes, such as poor bottom heating temperature stability and difficulty in controlling it, as well as the complex design of the steam heating structure and the induction detection mechanism for placing the inner pot in the pot, resulting in high production costs. This objective is achieved through the following technical solution.

[0004] An air fryer with a bottom IH coil heating plate. The air fryer has an inner pot housed within an opening on one side of the outer shell. The inner pot is provided with a handle on the outside. A first fan and electric heating tube are located in a groove at the top of the metal insulation layer above the inner pot. The first fan is connected to the motor shaft of a motor located at the top of the metal insulation layer within the machine head. An IH coil heating plate is located within the metal insulation layer below the inner pot. A second fan, serving as a cooling fan, is located within the machine body below the IH coil heating plate. The fan circuit board, motor, and electric heating tube for the second fan are connected to a PCB located at the top of the metal insulation layer within the machine head via wiring. Key structural design features include an inner pot greater than 110 mm in height, a grill within the inner pot, a non-magnetic pot or ferrite pot, and a ferrite grill. The grill is aligned with the IH coil heating plate below, and magnetic induction from the IH coil heating plate heats the grill within the inner pot through the inner pot. The air fryer incorporates an IH coil heating plate within the metal insulation layer, which heats the grill within the air fryer through a gap. Furthermore, a covered soup and rice pot is added below for steam cooking, eliminating the impact of cooking steam on the product through high-temperature heating and drying. Furthermore, an IH electromagnetic module within the IH coil heating plate detects the presence of an inner pot to determine whether heating is in effect. This results in a simpler structure and lower production costs. Compared to existing metal heating tube structures within the inner pot, the IH coil heating plate within the inner pot facilitates direct heat generation to the ferrite components, resulting in a higher heat conversion rate. In particular, when combined with the electric heating tube within the upper portion of the inner pot, this achieves better heating and cooking effects on the bottom of food on the ferrite grill, which is not in direct contact with the inner pot. Cooking effects on the upper and lower surfaces of the grilled food are also enhanced. The grill is preferably positioned close to the inner pot bottom. The grill and the glass wall below facilitate cleaning the inner pot bottom, reflecting the development trend of existing similar air fryers. When the inner pot is a ferrite pot, the IH coil heating plate can also heat food at the bottom of the inner pot.

[0005] When the inner pot is placed inside the machine body, the IH electromagnetic module in the IH coil heating plate generates a magnetic field that senses ferrite, generating resistance and a high current. The PCB triggers the IH coil heating plate, motor, and electric heating tube to operate. Therefore, before operation, the PCB first triggers the IH electromagnetic module in the IH coil heating plate to detect ferrite before triggering the corresponding components to operate. If the IH electromagnetic module in the IH coil heating plate does not detect ferrite, it indicates that the inner pot and its baking tray are not placed inside the machine body, and the corresponding components will not operate.

[0006] A microswitch is located on the inner edge of the housing's opening. This microswitch is connected to the PCB via a circuit. When the inner pot is inside the housing, the inner pot triggers the microswitch via a pin. This microswitch, combined with the IH electromagnetic module detection of the IH coil heating plate, provides enhanced safety. Alternatively, the microswitch can be omitted.

[0007] A glass layer is provided in the hollowed-out portion of the bottom of the inner pot. This facilitates the magnetic induction of the IH coil heating plate to pass through the inner pot to heat the grill inside the inner pot. This is particularly true when the inner pot is a non-magnetic pot such as an aluminum pot, or an iron pot. The glass layer on the bottom allows for better heating and heat conduction to the grill through the glass layer.

[0008] An NTC temperature sensor is located on one side of the groove at the top of the metal insulation layer above the inner pot in the housing. The NTC temperature sensor is connected to the PCB via a circuit. The NTC temperature sensor, along with the control chip and control program on the PCB, enables more precise control of the operation of the corresponding fan blades and heating components under different temperature conditions.

[0009] A soup and rice pot is arranged in the middle of the bottom of the inner pot, a pot mouth of the soup and rice pot is provided with a pot cover, and one side of the pot cover is provided with an exhaust hole.

[0010] An air guide cover is provided on the top of the metal insulation layer above the first fan blade, and a radial stirring fan blade is provided in the air guide cover. The motor is arranged on the top of the air guide cover, and the motor shaft of the motor is connected to the radial stirring fan blade and the first fan blade at the same time.

[0011] The grill has a flat center and symmetrically flanks with hollowed-out holes. The grill is secured in place by symmetrically stamped bosses on either side of the inner pot. This structure facilitates placement of the baking tray within the inner pot and the aforementioned soup and rice pot on the grill. The soup and rice pot can also be placed directly within the inner pot for use.

[0012] The inner pot is symmetrically provided with two handles on one side of the outer diameter, and the length of the inner pot is greater than the width and less than twice the width. The above is an embodiment of a large-capacity inner pot, and the inner pot can be set according to the capacity and the body.

[0013] The utility model has reasonable structural design, convenient production and assembly, low production cost, good safety, good heating effect, high efficiency, precise temperature sensing and temperature control; it is suitable for use as an air fryer with a bottom IH coil heating plate, and a structural improvement of similar products. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic cross-sectional view of an embodiment of the present invention, in which the dotted line on the top of the body represents the internal structure of the head, and the dotted line represents the magnetic induction line.

[0015] Figure 2 yes Figure 1 Schematic diagram of the three-dimensional structure of the inner pot.

[0016] Figure 3 yes Figure 2 Schematic diagram of the inner pot steam cooking state structure.

[0017] Figure 4 yes Figure 3 Schematic diagram of the three-dimensional structure of a soup rice pot.

[0018] Figure 5 yes Figure 3 Schematic diagram of the cross-sectional structure of steam cooking usage status.

[0019] Figure 6 yes Figure 5 Schematic diagram of the magnetic induction cross-sectional structure when the inner pot is removed, where the dotted lines are magnetic induction lines.

[0020] Serial numbers and names of the accompanying drawings: 1. Outer casing, 2. First fan blade, 3. Electric heating tube, 4. Inner pot, 5. Handle, 6. Grill, 7. IH coil heating plate, 8. Second fan blade, 9. Glass layer, 10. Radial stirring fan blade, 11. NTC temperature sensor, 12. Soup and rice pot, 13. Pot lid. Implementation Method

[0021] Now, in conjunction with the accompanying drawings, the structure and use of the utility model are further described. Figures 1-6 As shown, the air fryer has an opening on one side of its outer shell 1, housing an inner pot 4. A handle 5 is provided on the outside of the inner pot. A first fan blade 2 and an electric heating tube 3 are provided in a groove at the top of the metal insulation layer above the inner pot. The first fan blade is connected to the motor shaft of the motor located at the top of the metal insulation layer within the machine head. An IH coil heating plate 7 is located below the inner pot in the metal insulation layer. A second fan blade 8 is located within the machine body below the IH coil heating plate. The second fan blade functions as a cooling fan. The fan circuit board, motor, and electric heating tube for the second fan blade are connected to the PCB located at the top of the metal insulation layer within the machine head via wiring. The inner pot is greater than 110 mm tall and is equipped with a grill 6. The inner pot is a non-magnetic pot or a ferrite pot, and the grill is a ferrite grill. The grill is aligned with the IH coil heating plate below, and the magnetic induction of the IH coil heating plate heats the grill within the inner pot through the inner pot. When the inner pot is set inside the machine body, the IH electromagnetic module in the IH coil heating plate generates a magnetic field that induces the ferrite, generates resistance and large current, and the PCB circuit board triggers the IH coil heating plate, motor and electric heating tube to work.

[0022] A glass layer 9 is provided in the hollowed-out portion in the middle of the bottom of the inner pot; an NTC temperature sensor 11 is provided on one side of the groove at the top of the metal insulation layer above the inner pot in the outer shell, and the NTC temperature sensor is connected to the PCB circuit board via a line. A soup and rice pot 12 is provided in the middle of the bottom of the inner pot, and a pot lid 13 is provided at the mouth of the soup and rice pot, and an exhaust hole is provided on one side of the pot lid. The soup and rice pot is placed in the middle of the inner pot, and a reserved gap is provided between the outer diameter of the inner pot and the inner wall of the inner pot. A corresponding placement area is provided in the bottom of the inner pot. An air guide is provided on the top of the metal insulation layer above the first fan blade, and a radial stirring fan blade 10 is provided in the air guide. A motor is provided on the top of the air guide, and the motor shaft of the motor is connected to both the radial stirring fan blade and the first fan blade.

[0023] The grill has a flat center area and symmetrically formed hollowed-out areas on either side. The grill is secured in place by symmetrically stamped bosses on either side of the inner pot. Two handles are symmetrically positioned along one side of the inner pot. The inner pot is longer than it is wide and less than twice its width.

[0024] The air fryer has three design options:

[0025] Option 1, such as Figure 1 、 Figure 2 As shown, this air fryer features an IH coil heating plate at the bottom of the inner pot, with a grill inside. The grill is made of ferrite, and the inner pot is preferably made of a non-magnetic material (e.g., glass, plastic, or ceramic, with the aforementioned plastic being a high-temperature-resistant special fiber plastic). The working principle is as follows: The IH coil heating plate generates a high-speed, high-frequency oscillation magnetic field, which heats the grill in the inner pot, which then transfers heat to the food on top, achieving a three-dimensional, direct, and efficient heating effect.

[0026] Option 2, such as 3- Figure 5 As shown, the air fryer features a rice and soup pot within its inner pot, which also has a lid. The bottom of the air fryer also has an IH heating coil. Steam generated by heating is discharged through the lid's vents, where it is then dried out by the air fryer's electric heating system, minimizing the steam's effects on the machine. The operating principle is as follows: the IH coil heating coil heats the rice and soup pot, and the steam generated by the heated liquid is discharged. Simultaneously, the high temperature generated by the electric heating tube dries out the steam.

[0027] Option 2 is a simple embodiment of an air fryer with a steam cooking function. On the one hand, it can conveniently cook soup, rice and other foods, and can be configured with as many soup pots or rice pots as desired to simultaneously meet the needs of cooking a variety of foods and consumers. On the other hand, the generated steam is dried by the electric heating tube or blown out of the body by the fan blades.

[0028] Option three, such as Figure 6As shown, the air fryer features an IH coil heating plate at the bottom. Since the IH principle uses electromagnetic waves to generate high-frequency oscillations, it requires the presence of a ferrite. Utilizing this principle, when the inner pot is removed from the air fryer, the IH coil heating plate loses contact with the pot and does not heat it. Furthermore, the top heating element remains unheated, protecting consumer safety and reducing the cost of traditional micro switches. The operating principle is as follows: the IH coil heating plate generates a magnetic field. When the inner pot is inside the air fryer, this magnetic field senses the ferrite, generating resistance and a high current. If the inner pot is removed, the magnetic field no longer senses the ferrite, resulting in no resistance or current, thus confirming that the inner pot is not inside the air fryer.

[0029] In summary, the air fryer includes a new type of air fryer and its inner pot detection and judgment method. The air fryer adopts the magnetic induction function of the IH principle, is simple and efficient, has diverse structural forms, a wide range of applications, low production cost, and has market promotion value.

[0030] The above content is intended to illustrate the technical means of the present invention and is not intended to limit the technical scope of the present invention. Those skilled in the art who, in combination with existing common knowledge, make obvious improvements or substitutions to the present invention also fall within the scope of protection of the claims of the present invention.

Claims

1. An air fryer with an IH coil heating plate at the bottom, wherein an inner pot (4) is provided in an opening on one side of a shell (1) of the air fryer, a handle (5) is provided on the outside of the inner pot, a first fan blade (2) and an electric heating tube (3) are provided in a groove at the top of a metal insulation layer above the inner pot in the shell, and the first fan blade is connected to a motor shaft of a motor provided at the top of the metal insulation layer in the machine head; an IH coil heating plate (7) is provided at the metal insulation layer at the bottom below the inner pot in the shell, a second fan blade (8) is provided in the machine body below the IH coil heating plate, the second fan blade is a cooling fan, and a fan blade circuit board of the second fan blade, a motor and an electric heating tube are connected to a PCB circuit board provided at the top of the metal insulation layer in the machine head through a line; and the characteristics are as follows: The inner pot (4) is provided with a grill (6), the inner pot is a non-magnetic pot body or a ferrite pot body, and the grill is a ferrite grill; the grill is aligned with the IH coil heating plate (7) below, and the magnetic induction of the IH coil heating plate heats the grill in the inner pot through the inner pot.

2. The bottom IH coil heating plate air fryer according to claim 1, characterized in that When the inner pot (4) is arranged inside the machine body, the IH electromagnetic module in the IH coil heating plate (7) generates a magnetic field that induces the ferrite, generates resistance and a large current, and the PCB circuit board triggers the IH coil heating plate, the motor and the electric heating tube (3) to work.

3. The bottom IH coil heating plate air fryer according to claim 1 or 2, characterized in that A micro switch is provided at the inner edge of the opening on one side of the housing (1), and the micro switch is connected to the PCB circuit board through a line. When the inner pot (4) is inside the body, the inner pot triggers the micro switch through the ejector pin.

4. The bottom IH coil heating plate air fryer according to claim 1, characterized in that A glass layer (9) is provided in the hollowed-out portion in the middle of the bottom of the inner pot (4).

5. The bottom IH coil heating plate air fryer according to claim 1, characterized in that An NTC temperature sensor (11) is provided on one side of the top groove of the metal heat insulation layer above the inner pot (4) in the housing (1), and the NTC temperature sensor is connected to the PCB circuit board via a line.

6. The bottom IH coil heating plate air fryer according to claim 1, characterized in that A soup and rice pot (12) is provided in the middle of the bottom of the inner pot (4), and a pot cover (13) is provided at the pot mouth of the soup and rice pot, and an exhaust hole is provided on one side of the pot cover.

7. The bottom IH coil heating plate air fryer according to claim 1, characterized in that An air guide cover is provided on the top of the metal heat insulation layer above the first fan blade (2), and a radial stirring fan blade (10) is provided inside the air guide cover. A motor is provided on the top of the air guide cover, and a motor shaft of the motor is connected to the radial stirring fan blade and the first fan blade at the same time.

8. The bottom IH coil heating plate air fryer according to claim 1, characterized in that The grill (6) is provided with a plane area in the middle and hollow through-hole areas symmetrically provided on both sides. The grill is fixed by bosses symmetrically provided and stamped on both sides of the pot body of the inner pot (4).

9. The bottom IH coil heating plate air fryer according to claim 1, characterized in that Two handles (5) are symmetrically provided on one side of the outer diameter of the inner pot (4); the length of the inner pot is greater than the width and less than twice the width.

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