Microwave air fryer based on temperature difference induction

Abstract

The invention discloses a microwave air fryer based on temperature difference induction, and relates to the technical field of microwave ovens, the microwave air fryer comprises a microwave oven outer shell, a double-layer furnace pipe capable of absorbing microwave energy is placed in an inner cavity of the microwave oven outer shell, and a thermal electric fan assembly capable of enabling internal cold and hot air to generate convection is installed at the top of the inner wall of the double-layer furnace pipe; a double-layer storage disc is fixedly installed at the bottom of the inner wall of the double-layer furnace pipe, an inner cavity of the double-layer storage disc is divided into an upper-layer cavity and a lower-layer cavity through a partition plate, and the flow speed of hot gas between the upper-layer cavity and the lower-layer cavity can be changed by rotating the partition plate. Function division and efficient heating are both considered through the split type double-layer furnace pipe structure, the hot air fan assembly achieves dynamic adjustment of the hot air position based on temperature difference self-power supply, the partition plate is combined to control the flow speed of bottom-layer airflow of food materials, heat permeation of dead zones at the bottoms of the food materials is enhanced, and the problems that the food materials of a microwave air fryer are prone to dry and pain are solved; meanwhile, the heating efficiency and the taste of the food materials are considered.

Description

Technical Field

[0001] This invention relates to the field of microwave oven technology, specifically to a microwave air fryer based on temperature difference sensing. Background Technology

[0002] A microwave oven is a common kitchen appliance that uses microwaves to heat food. Its working principle is to generate microwaves through a magnetron. The microwaves penetrate the food and cause the molecules to vibrate, generating heat, thus achieving rapid heating. An air fryer is a kitchen appliance that uses high-speed circulating hot air to cook food instead of traditional frying. Its core principle is to heat the air quickly and circulate it over the surface of the food, using the food's own oil and moisture to bake it, thus achieving a crispy texture similar to deep-frying, while reducing oil intake. Currently, there are also some microwave-air fryer combos that add a hot air circulation function to the microwave oven, enabling both rapid microwave heating and air frying through hot air circulation. However, traditional microwave ovens have a large cavity size, resulting in a slow overall heating rate during hot air circulation. Uneven distribution of hot air inside the cavity can also lead to overcooking or undercooking of food in certain areas, affecting both taste and efficiency. Furthermore, the principle of existing microwave energy in heating food is to cause the water molecules inside the food to vibrate at high frequency in the microwave field, and the friction between the molecules generates heat, thereby achieving heating from the inside out. However, when combined with the air frying function, if the hot air acts directly on the surface of the food in the initial stage, it will quickly evaporate the water molecules on the surface of the food, causing the surface of the food to harden prematurely, hindering the evaporation of internal moisture and the transfer of heat, making it difficult for the inside of the food to cook through, resulting in a phenomenon of burnt outside and raw inside.

[0003] To address the aforementioned issues, there is an urgent need for innovative designs based on existing microwave air fryers. Summary of the Invention

[0004] The present invention addresses the problem of overly simplistic solutions in existing technologies by providing a significantly different solution. Specifically, the present invention aims to provide a microwave air fryer based on temperature difference sensing, thereby solving the problems mentioned in the background section regarding the large size of the oven chamber, slow heating, and premature application of hot air to the food surface, which can cause the food to be burnt on the outside but raw on the inside.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a microwave air fryer based on temperature difference sensing, comprising a microwave oven shell, wherein a double-layered oven cavity capable of absorbing microwave energy is placed in the inner cavity of the microwave oven shell, a thermoelectric fan assembly capable of causing convection of hot and cold air inside is installed on the top of the inner wall of the double-layered oven cavity, and a double-layered storage tray is fixedly installed on the bottom of the inner wall of the double-layered oven cavity, wherein the inner cavity of the double-layered storage tray is separated into an upper chamber and a lower chamber by a partition plate, and by rotating the partition plate, the flow rate of hot gas between the upper chamber and the lower chamber can be changed, thereby realizing dynamic control of the hot air in the inner cavity of the double-layered storage tray at different cooking stages.

[0006] Preferably, the double-layer furnace liner is divided into an upper furnace liner and a lower furnace liner, the thermoelectric driven fan assembly is installed in the inner cavity of the upper furnace liner, and the double-layer storage tray is installed in the inner cavity of the lower furnace liner.

[0007] Preferably, the thermoelectric fan assembly includes a fan body, an air box is sleeved on the air outlet of the fan body, an output pipe is fixedly connected to the bottom of the air box, a sleeve is rotatably connected to one end of the output pipe, and a plurality of air slots are opened on the lower end face of the output pipe. The main body of the fan includes a casing, an impeller and a main shaft. A DC motor is installed inside the casing. The lower end of the main shaft extends through to the outside of the output pipe and is fixedly connected to the sleeve.

[0008] Preferably, a circular baffle is fixedly connected to the inner wall of the upper furnace liner, the blower body is located on the upper surface of the circular baffle, the sleeve is located on the lower surface of the circular baffle, the output pipe passes through the upper surface to the lower surface of the circular baffle, a thermoelectric converter is installed on the upper surface of the circular baffle, and the thermoelectric converter is electrically connected to the DC motor in the blower body casing.

[0009] Preferably, a limiting shaft is fixedly connected to the outer wall of the sleeve, and a hollow tube is sleeved on the outside of the limiting shaft. One side of the hollow tube is connected to the sleeve through a flexible tube, and the other side of the hollow tube is fixedly connected to the front end of the limiting shaft through a return spring. An air outlet is opened on the side curved surface of the hollow tube, and the air outlet is set towards the direction of the double-layer storage tray.

[0010] Preferably, the double-layer storage tray is divided into an upper storage plate and a lower storage plate. The upper storage plate has a number of mesh holes, and the lower storage plate has a number of lower mesh holes. The lower mesh holes and the mesh holes are arranged correspondingly, and the number of lower mesh holes is less than that of the mesh holes. Furthermore, the diameter of the mesh holes is slightly larger than that of the lower mesh holes.

[0011] Preferably, the spacer plate has a plurality of circular through holes at the positions corresponding to the lower mesh holes, and the diameter of the circular through holes is the same as the diameter of the lower mesh holes.

[0012] Preferably, a protrusion is fixedly connected to the lower surface of the partition plate, and a swing arm is rotatably connected to the bottom of the lower shelf via a shaft. A torsion spring is sleeved on the outside of the shaft. One end of the torsion spring is fixedly connected to the lower shelf, and the other end of the torsion spring is fixedly connected to the swing arm. One end of the swing arm is provided with a groove through which the protrusion can pass, and the other end of the swing arm is fixedly connected to an iron block. Preferably, a coil is installed on the lower shelf, a magnet is connected inside the coil, and the two ends of the coil are electrically connected to the positive and negative poles of the thermoelectric converter through two wires respectively. Several reflux vents are opened on the edges of the lower shelf and the circular baffle.

[0013] Compared with the prior art, the beneficial effects of the present invention are: This invention adopts a split double-layer furnace structure, which divides the furnace into an upper furnace and a lower furnace, realizing functional zoning and modular integration. The upper furnace is dedicated to installing the thermoelectric fan assembly, providing an independent and stable working environment, avoiding interference from oil and steam during cooking, and ensuring operational stability and service life. The lower furnace serves as the main cooking space, supporting the double-layer storage tray to form a high-efficiency heating cavity. Both are covered with microwave-absorbing material, which can directly absorb microwave energy for rapid heating. The combination of the two forms a compact heating chamber, significantly reducing the volume of hot air circulation, making the heat more concentrated and the heating faster, thus solving the problems of large overall cavity and slow preheating of traditional microwave air fryers. This invention combines a thermoelectric converter with a fan drive system, utilizing the Seebeck effect to achieve self-sufficiency in energy. The thermoelectric converter is attached to a circular metal baffle, generating electricity through the temperature difference created by the heating at its hot end and the cooling at its cold end, providing initial power to the DC motor of the fan without the need for an external power source or battery. The main shaft and sleeve of the fan body are fixedly connected. By utilizing the output characteristics of the thermoelectric converter, the directional delivery of hot air at different stages can be achieved, enabling phased dynamic air distribution. In the initial cooking stage, the hot air is controlled at the edge of the double-layer oven cavity, not directly acting on the surface of the food, thus preventing premature loss of water molecules from the food surface. In the subsequent processing stage, the hot air gradually transitions to the surface of the food, achieving both efficient hot air envelopment and maximum moisture retention of the food, balancing heating efficiency and food texture. This invention features a rotatable partition plate within a double-layered tray, allowing for airflow regulation between the upper and lower chambers. A high current supplied by a thermoelectric converter is applied to the coil, generating a strong magnetic field that attracts an iron block. This drives a swing arm to overcome the torsion spring, causing the partition plate to rotate until the through-hole aligns with the lower mesh, creating the minimum flow cross-section. Based on Bernoulli's principle, a high-speed jet is generated, accelerating bottom air circulation, rapidly expelling cold air, and improving heating efficiency. As cooking progresses, the thermoelectric output weakens, the electromagnetic force decreases, and the torsion spring resets, causing the swing arm to swing back, misaligning the through-hole with the lower mesh to form a labyrinthine slit channel. This significantly increases airflow resistance, reduces flow velocity, and prolongs the residence time of hot air in the lower chamber, enhancing heat penetration into the bottom blind spots of the food. This effectively solves the problems of uneven heating and insufficient bottom heating in traditional air fryers. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 This is a cross-sectional view of the double-layer furnace shell of the present invention.

[0016] Figure 3 This is a schematic diagram of the double-layer furnace shell structure after unfolding according to the present invention.

[0017] Figure 4 This is a bottom view of the upper furnace shell structure of the present invention.

[0018] Figure 5 This is a cross-sectional structural diagram of the bellows, output pipe, and sleeve of the present invention.

[0019] Figure 6 This is a schematic diagram of the unfolded structure of the double-layer storage tray of the present invention.

[0020] Figure 7 For the present invention Figure 6 Enlarged structural diagram at point A in the middle.

[0021] Figure 8 This is a diagram showing the working state of the spacer plate after rotation according to the present invention.

[0022] Figure 9 This is a cross-sectional view of the double-layer storage tray of the present invention.

[0023] In the diagram: 1. Microwave oven outer shell; 2. Double-layer oven cavity; 201. Upper oven cavity; 202. Lower oven cavity; 3. Thermoelectric fan assembly; 301. Air box; 302. Output pipe; 303. Sleeve; 304. Main shaft; 305. Limiting shaft; 306. Thermoelectric converter; 307. Hollow tube; 308. Flexible hose; 309. Return spring; 4. Double-layer storage tray; 401. Upper storage plate; 402. Lower storage plate; 403. Mesh hole; 404. Lower mesh hole; 5. Divider plate; 501. Circular through hole; 502. Protrusion; 503. Swing rod; 504. Torsion spring; 505. Iron block; 506. Coil; 507. Magnet; 6. Upper cavity; 7. Lower cavity; 8. Circular baffle; 9. Return vent; 10. Wire. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Please see Figures 1 to 9 The present invention provides a technical solution: a microwave air fryer based on temperature difference sensing, including a microwave oven shell 1, a double-layer oven liner 2 that can absorb microwave energy placed in the inner cavity of the microwave oven shell 1, a hot air fan assembly 3 that can cause convection of hot and cold air inside the double-layer oven liner 2 installed on the top of the inner wall of the double-layer oven liner 2, a double-layer tray 4 fixedly installed on the bottom of the inner wall of the double-layer oven liner 2, the inner cavity of the double-layer tray 4 is separated into an upper chamber 6 and a lower chamber 7 by a partition 5, by rotating the partition 5, the hot gas flow rate between the upper chamber 6 and the lower chamber 7 can be changed, so as to realize the dynamic control of the hot air in the inner cavity of the double-layer tray 4 at different cooking stages; The microwave oven shell 1 is combined with a double-layered oven liner 2 that can absorb microwave energy, providing a stable carrier for subsequent heat control and efficient heating, thus meeting the dual needs of microwave heating and air frying. The hot air fan assembly 3 breaks away from the traditional fixed air blowing mode of fans and can achieve phased dynamic air distribution. In the initial cooking stage, the hot air is controlled at the edge of the double-layer oven cavity 2 and does not directly act on the surface of the food to avoid premature loss of water molecules on the surface of the food. In the subsequent processing stage, the hot air gradually transitions to the surface of the food, which not only achieves efficient hot air surrounding and wrapping, but also locks in the moisture of the food to the maximum extent, taking into account both heating efficiency and food taste. The double-layered tray 4 is separated into an upper chamber 6 and a lower chamber 7 by a partition plate 5. By rotating the partition plate 5, the hot gas flow rate between the two chambers can be dynamically changed, achieving precise control of the hot gas at different cooking stages. The gas flow rate is fastest in the initial stage of heating to ensure rapid heating. In the later stage of heating, the air flow rate slows down, extending the residence time of the hot gas in the inner cavity of the tray. This effectively covers the heating blind spot of the lower layer of food and improves the heating uniformity of the upper and lower layers of food. It not only solves the pain points of traditional microwave air fryers where food is easy to dry and unevenly heated, but also takes into account both heating efficiency and food taste.

[0026] In this embodiment, as Figure 1 , Figure 2 and Figure 3 As shown, the double-layer furnace liner 2 is divided into an upper furnace liner 201 and a lower furnace liner 202. The thermoelectric driven fan assembly is installed in the inner cavity of the upper furnace liner 201, and the double-layer storage tray 4 is installed in the inner cavity of the lower furnace liner 202. The thermoelectric fan assembly 3 includes a fan body, an air box 301 is sleeved at the air outlet of the fan body, an output pipe 302 is fixedly connected to the bottom of the air box 301, a sleeve 303 is rotatably connected to one end of the output pipe 302, and several air slots are opened on the lower end face of the output pipe 302. The main body of the fan includes a casing, an impeller and a main shaft 304. A DC motor is installed inside the casing. The lower end of the main shaft 304 extends through to the outside of the output pipe 302 and is fixedly connected to the sleeve 303. A circular baffle 8 is fixedly connected to the inner wall of the upper furnace liner 201. The main body of the blower is located on the upper surface of the circular baffle 8, and the sleeve 303 is located on the lower surface of the circular baffle 8. The output pipe 302 passes through the upper surface of the circular baffle 8 to the lower surface. A thermoelectric converter 306 is installed on the upper surface of the circular baffle 8. The thermoelectric converter 306 is electrically connected to the DC motor in the blower main body casing. A limiting shaft 305 is fixedly connected to the outer wall of the sleeve 303. A hollow tube 307 is sleeved on the outside of the limiting shaft 305. One side of the hollow tube 307 is connected to the sleeve 303 through a flexible hose 308. The other side of the hollow tube 307 is fixedly connected to the front end of the rod of the limiting shaft 305 through a return spring 309. An air outlet is opened on the side curved surface of the hollow tube 307, and the air outlet is set towards the double-layer storage tray 4. It should be noted that by splitting the double-layer oven liner 2 into an upper oven liner 201 and a lower oven liner 202, modular installation is achieved, eliminating the need for additional heating elements. The upper oven liner 201 and the lower oven liner 202 are covered with microwave-absorbing material, which can absorb microwave energy and heat up quickly when the microwave is turned on inside the microwave oven. The two layers are independent and separable, and when put together, they can form a small heating chamber, effectively reducing the space for hot air circulation. Compared with the traditional large oven liner design, the heat is more concentrated and the heating speed is faster, solving the problem of slow overall heating. A small round groove is provided on the top of the upper oven liner 201 to release water vapor and maintain internal and external pressure balance. The upper oven liner 201 is specifically designed to install the electric heating fan assembly 3, providing it with an independent and stable working space. This ensures that the fan assembly is not affected by factors such as oil stains and steam that may be generated in the lower cooking area during operation, thereby guaranteeing its working stability and service life. The lower oven liner 202 serves as the main cooking space and is used to install the double-layer storage tray 4. This partitioned design makes heat management and control more precise. In addition, for example Figure 4 and Figure 5 As shown, the thermoelectric fan assembly 3 is mainly composed of a fan body, a wind box 301, an output pipe 302, and a sleeve 303. The DC motor inside the fan body drives the impeller to rotate and generate airflow. The airflow is gathered by the wind box 301 and enters the output pipe 302. The air groove opened on the lower end face of the output pipe 302 guides the airflow into the sleeve 303 which is rotatably connected to it. The lower end of the main shaft 304 of the fan body is fixedly connected to the sleeve 303, so that the DC motor can drive the sleeve 303 to rotate synchronously when it works. A hollow tube 307 is sleeved on the limiting shaft 305 on the outer wall of the sleeve 303. The hollow tube 307 is connected to the sleeve 303 through a flexible tube 308, thereby receiving the airflow delivered by the sleeve 303 and blowing it to the double-layer storage tray 4 through the air outlet opened on the side curved surface. The other side of the hollow tube 307 is fixedly connected to the front end of the limiting shaft 305 via a return spring 309. This structural design allows the hollow tube 307 to achieve a certain degree of radial displacement under the combined action of centrifugal force and return spring 309 during the rotation of the sleeve 303, thereby adjusting the blowing range of the air outlet. Specifically, a thermoelectric converter 306 is installed on the upper surface of a circular baffle 8 to provide power to the DC motor of the main fan body. One end of the thermoelectric converter 306 is attached to the heated circular baffle 8, which is made of metal and has excellent thermal conductivity. It can quickly absorb microwave energy and transfer heat to the hot end of the thermoelectric converter 306. The cold end of the thermoelectric converter 306 is in contact with the air in the upper furnace chamber 201. Electrical energy is generated through the temperature difference between the hot and cold ends. The Seebeck principle is used to realize the direct conversion of heat energy to electrical energy, providing self-sufficient power support for the DC motor in the main fan body. No external power supply or backup battery is required. This simplifies the equipment circuit and reduces the risk of equipment downtime due to power module failure. It has the dual advantages of energy saving, environmental protection and improved reliability. This heat energy conversion technology belongs to the existing technology. In addition, as the internal air temperature approaches the shell temperature, the temperature difference decreases, the output voltage of the thermoelectric converter 306 weakens, the current gradually decreases, the rotational speed of the spindle 304 decreases synchronously, and the hollow tube 307 gradually contracts towards the sleeve 303 under the pulling force of the return spring 309. By fixing the main shaft 304 and the sleeve 303 of the fan body together, and utilizing the output characteristics of the thermoelectric converter 306, the temperature difference decreases, the voltage and current drop, and the fan speed decreases. This, combined with the mechanical tension of the return spring 309, enables the directional delivery of hot air at different stages. Specifically, in the initial stage of cooking, due to the large temperature difference between the two ends of the thermoelectric converter 306, the output voltage and current are high, and the DC motor drives the main shaft 304 to rotate at high speed. At this time, the sleeve 303 rotates rapidly with the main shaft 304, and the hollow tube 307 is thrown outward under the action of centrifugal force, overcoming the tension of the return spring 309. This causes the air outlet to be biased towards the inner wall edge of the double-layer oven liner 2. After the hot air is blown out from the air outlet, it first flows along the inner edge of the double-layer oven liner 2 to preheat the internal space of the oven liner. At the same time, it avoids blowing directly on the surface of the food before the food has fully absorbed microwave energy and the interior has not yet started to heat up, effectively preventing premature hardening caused by the rapid evaporation of water molecules on the surface of the food. As cooking time increases, the internal temperature of the double-layer oven liner 2 gradually rises, the temperature difference between the hot and cold ends of the thermoelectric converter 306 gradually decreases, its output voltage and current weaken accordingly, the speed of the DC motor decreases, and the rotation speed of the main shaft 304 slows down. At this time, the effect of centrifugal force on the hollow tube 307 weakens, and the tension of the return spring 309 gradually becomes dominant, pulling the hollow tube 307 back towards the sleeve 303, so that the direction of the air outlet gradually transitions from the inner edge of the double-layer oven liner 2 to the surface of the food on the double-layer tray 4. When a certain temperature is reached, the hot air can be precisely blown onto the surface of the food to achieve the effect of air frying, making the surface of the food golden and crispy, and providing precise hot air support for different cooking stages. In this embodiment, as Figures 6 to 9 As shown, the double-layer storage tray 4 is divided into an upper storage plate 401 and a lower storage plate 402. The upper storage plate 401 has several mesh holes 403, and the lower storage plate 402 has several lower mesh holes 404. The lower mesh holes 404 and the mesh holes 403 are arranged correspondingly, and the number of lower mesh holes 404 is less than the number of mesh holes 403. Furthermore, the diameter of the mesh holes 403 is slightly larger than the diameter of the lower mesh holes 404.

[0027] Several circular through holes 501 are provided on the partition plate 5 at the position corresponding to the lower mesh hole 404. The diameter of the circular through holes 501 is the same as the diameter of the lower mesh hole 404.

[0028] A protrusion 502 is fixedly connected to the lower surface of the partition plate 5. The bottom of the lower shelf 402 is rotatably connected to a swing rod 503 via a shaft. A torsion spring 504 is sleeved on the outside of the shaft. One end of the torsion spring 504 is fixedly connected to the lower shelf 402, and the other end of the torsion spring 504 is fixedly connected to the swing rod 503. One end of the swing rod 503 is provided with a groove through which the protrusion 502 can pass. The other end of the swing rod 503 is fixedly connected to an iron block 505. A coil 506 is installed on the lower shelf 402. A magnet 507 is connected inside the coil 506. The two ends of the coil 506 are electrically connected to the positive and negative poles of the thermoelectric converter 306 through two wires 10 respectively. Several reflux vents 9 are opened on the edges of the lower shelf 402 and the circular baffle 8.

[0029] It should be noted that the upper shelf 401 and lower shelf 402 of the double-layer storage tray 4 are respectively provided with mesh holes 403 and lower mesh holes 404. A circular through hole 501 is also provided on the middle partition plate 5. The circular through hole 501 is used to connect the upper chamber 6 and the lower chamber 7. The mesh holes 403 have a large diameter and a large number, which completely cover the upper surface of the upper shelf 401. They are used to receive the hot air delivered from the thermoelectric fan assembly 3, ensuring that the hot air can enter the upper chamber 6 evenly and act on the bottom of the food. Subsequently, the hot air enters the lower chamber 7 through the circular through-hole 501 of the partition plate 5. The number of lower mesh holes 404 is relatively small and the diameter is slightly smaller. They are mainly distributed in the central area. In conjunction with the circular through-hole 501 on the partition plate 5, the circular through-hole 501 is aligned with the lower mesh hole 404 in the initial heating stage. In the initial stage, the circular through-hole 501 of the partition plate 5 is precisely aligned with the lower mesh hole 404 of the lower shelf 402. When the hot air passes through the combined channel of the circular through-hole 501 and the lower mesh hole 404, the flow area is greatly reduced. Based on Bernoulli's principle, the airflow velocity is significantly increased, forming a local jet shape. It quickly carries the cold air in the lower area of ​​the food and discharges it. On the one hand, it accelerates the hot air circulation rate in the lower chamber 7, avoids the hot air from stagnating in the chamber, improves the heat energy utilization rate, and enhances the heat exchange efficiency of the hot air at the bottom of the food. On the other hand, the high-speed airflow can form a slight negative pressure at the bottom of the food, which helps the upper hot air to penetrate down better and improves the overall heating uniformity. As cooking progresses, when it is necessary to extend the residence time of hot air in the plate to improve the uniformity of heating, the baffle rotates, and the circular through hole 501 and the lower mesh hole 404 are misaligned, forming a labyrinthine slit channel. The airflow cannot pass through directly. At this time, the initial channel effect disappears. After the airflow enters the upper chamber 6, it will not quickly pass through the circular through hole 501 and directly enter the lower chamber 7. The airflow speed changes from a high-speed jet to a low-speed vortex, and it stays at the bottom of the food, extending the contact time and allowing the hot air to contact the bottom of the food more fully, effectively covering the heating blind spot of the lower layer of the food. The design of the partition plate 5 is the core of achieving dynamic control of hot air. A protrusion 502 is fixedly connected to the lower surface of the partition plate 5. The position of the protrusion 502 is driven by the swing rod 503. When the swing rod 503 rotates, it can move the protrusion 502, thereby driving the partition plate 5 to rotate. The other end of the swing rod 503 is fixedly connected to an iron block 505. A coil 506 is set on the lower shelf 402, and a magnet 507 is sleeved inside the coil 506. One end of the magnet 507 is connected to the lower shelf. The plate 402 is fixedly connected, and the other end is aligned with the iron block 505 of the swing rod 503. The two ends of the coil 506 are electrically connected to the positive and negative poles of the thermoelectric converter 306 through the wire 10. The wire 10 can be led out from the wire hole on one side of the lower furnace liner 202 and connected to the thermoelectric converter 306 in the upper furnace liner 201. In addition, a protective shell can be added to the outside of the coil 506 according to the actual application environment to prevent the coil 506 from directly contacting the high temperature air and extend the service life of the wire 10. As the output current of the thermoelectric converter 306 changes during cooking, the current in the coil 506 also changes. According to Abe's rule, the coil 506 generates a changing magnetic field, which interacts with the magnet 507 to produce an electromagnetic force. In the initial stage of cooking, the output current of the thermoelectric converter 306 is relatively large, and the electromagnetic force generated by the coil 506 is relatively strong, attracting the iron block 505, causing the swing rod 503 to overcome the elastic force of the torsion spring 504 and start to swing and maintain the angle. The upper shelf 401 has a groove for the swing rod 503 to swing, ensuring that there are no other obstructing parts during the swing of the swing rod 503. When the voltage and current are large, the circular through hole 501 on the partition plate 5 is precisely aligned with the lower mesh hole 404 of the lower shelf 402, and the hot air channel is fully opened to ensure the maximum airflow and achieve rapid heating. As cooking progresses into the later stages, the output current of the thermoelectric converter 306 decreases, and the electromagnetic force generated by the coil 506 decreases accordingly. At this time, the restoring force of the torsion spring 504 gradually exceeds the electromagnetic attraction force, pulling the swing rod 503 to swing in the opposite direction, causing the partition plate 5 to rotate, so that the circular through hole 501 and the lower mesh hole 404 gradually become misaligned, partially blocking the hot air passage, reducing the hot air flow rate, and enabling more full contact with the lower layer of food, effectively covering the heating blind spots that are prone to occur in traditional designs. Furthermore, the return air holes 9 opened on the edges of the lower shelf 402 and the circular baffle 8 form a hot air circulation channel. The return air holes 9 are located on the outermost ring and are spaced apart from the hollow tube 307. The inner cavity of the double-layer furnace 2 is driven by the wind force of the fan body, and the airflow flows from top to bottom. After passing through the upper chamber 6 and the lower chamber 7 and flowing to the bottom of the lower furnace 202, it will flow upward along the return air holes 9 on the edge of the lower shelf 402 and return to the vicinity of the fan body of the upper furnace 201 through the return air holes 9 on the edge of the circular baffle 8, forming a complete hot air circulation system. This circulation design allows the hot air to be reused, reduces heat loss, and further improves energy utilization efficiency.

[0030] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microwave air fryer based on temperature difference sensing, comprising a microwave oven shell (1), wherein the inner cavity of the microwave oven shell (1) is provided with a double-layered oven liner (2) capable of absorbing microwave energy, characterized in that: The top of the inner wall of the double-layer oven (2) is equipped with a thermoelectric fan assembly (3) that enables convection of hot and cold air inside. The bottom of the inner wall of the double-layer oven (2) is fixedly installed with a double-layer tray (4). The inner cavity of the double-layer tray (4) is separated into an upper chamber (6) and a lower chamber (7) by a partition plate (5). By rotating the partition plate (5), the flow rate of hot gas between the upper chamber (6) and the lower chamber (7) can be changed, so as to achieve dynamic control of the hot air in the inner cavity of the double-layer tray (4) at different cooking stages.

2. A microwave air fryer based on temperature difference sensing according to claim 1, characterized in that: The double-layer furnace liner (2) is divided into an upper furnace liner (201) and a lower furnace liner (202). The thermoelectric fan assembly (3) is installed in the inner cavity of the upper furnace liner (201), and the double-layer storage tray (4) is installed in the inner cavity of the lower furnace liner (202).

3. A microwave air fryer based on temperature difference sensing according to claim 2, characterized in that: The thermoelectric fan assembly (3) includes a fan body, an air box (301) is sleeved on the air outlet of the fan body, an output pipe (302) is fixedly connected to the bottom of the air box (301), a sleeve (303) is rotatably connected to one end of the output pipe (302), and several air slots are opened on the lower end face of the output pipe (302). The main body of the fan includes a casing, an impeller and a main shaft (304). A DC motor is installed inside the casing. The lower end of the main shaft (304) extends through to the outside of the output pipe (302) and is fixedly connected to the sleeve (303).

4. A microwave air fryer based on temperature difference sensing according to claim 3, characterized in that: A circular baffle (8) is fixedly connected to the inner wall of the upper furnace chamber (201). The main body of the fan is located on the upper surface of the circular baffle (8). The sleeve (303) is located on the lower surface of the circular baffle (8). The output pipe (302) passes through the upper surface of the circular baffle (8) to the lower surface. A thermoelectric converter (306) is installed on the upper surface of the circular baffle (8). The thermoelectric converter (306) is electrically connected to the DC motor in the fan main body casing.

5. A microwave air fryer based on temperature difference sensing according to claim 3, characterized in that: The outer wall of the sleeve (303) is fixedly connected to a limiting shaft (305). A hollow tube (307) is sleeved on the outside of the limiting shaft (305). One side of the hollow tube (307) is connected to the sleeve (303) through a flexible tube (308). The other side of the hollow tube (307) is fixedly connected to the front end of the limiting shaft (305) through a return spring (309). An air outlet is provided on the side curved surface of the hollow tube (307). The air outlet is set towards the double-layer storage tray (4).

6. A microwave air fryer based on temperature difference sensing according to claim 1, characterized in that: The double-layer storage tray (4) is divided into an upper storage plate (401) and a lower storage plate (402). The upper storage plate (401) has a number of mesh holes (403), and the lower storage plate (402) has a number of lower mesh holes (404). The lower mesh holes (404) and the mesh holes (403) are arranged correspondingly, and the number of lower mesh holes (404) is less than that of mesh holes (403). The diameter of the mesh holes (403) is slightly larger than that of the lower mesh holes (404).

7. A microwave air fryer based on temperature difference sensing according to claim 6, characterized in that: The spacer plate (5) has several circular through holes (501) at the positions corresponding to the lower mesh hole (404), and the diameter of the circular through holes (501) is the same as the diameter of the lower mesh hole (404).

8. A microwave air fryer based on temperature difference sensing according to claim 6, characterized in that: The lower surface of the partition plate (5) is fixedly connected to a protrusion (502). The bottom of the lower shelf (402) is rotatably connected to a swing rod (503) via a shaft. A torsion spring (504) is sleeved on the outside of the shaft. One end of the torsion spring (504) is fixedly connected to the lower shelf (402), and the other end of the torsion spring (504) is fixedly connected to the swing rod (503). One end of the swing rod (503) is provided with a groove through which the protrusion (502) can pass. The other end of the swing rod (503) is fixedly connected to an iron block (505).

9. A microwave air fryer based on temperature difference sensing according to claim 6, characterized in that: A coil (506) is installed on the lower shelf (402). A magnet (507) is connected inside the coil (506). The two ends of the coil (506) are electrically connected to the positive and negative poles of the thermoelectric converter (306) through two wires (10). Several reflux vents (9) are opened on the edges of the lower shelf (402) and the circular baffle (8).

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