High efficiency back-blast air fryer

Abstract

This utility model relates to a high-efficiency back-blowing air fryer, addressing the technical problems of low fluid energy efficiency and high turbulence in existing similar products, resulting in significant fluid energy loss and chaotic flow that fails to benefit the food. The key features are: the hot air mechanism and heat dissipation mechanism on the back of the metal heat insulation cover of the air fryer are angled towards the bottom of the machine body; the groove in the middle of the back of the metal heat insulation cover is rectangular; the inner plane of the groove has equidistant internal through holes; the groove of the metal heat insulation cover protrudes triangularly towards the back; and the hot air impeller, heating pipe, and heat dissipation impeller within the hot air mechanism and heat dissipation mechanism are parallel to each other; the circumferential plate surface of the groove of the metal heat insulation cover is 4-5mm away from the impeller surface of the hot air impeller within the heat insulation guide shroud of the hot air mechanism; through holes are provided on the outer diameter plane, top, and one side of the pot body of the groove of the metal heat insulation cover; one side of the protruding cavity at the top of the metal heat insulation cover above the pot opening communicates with the through hole above the groove of the metal heat insulation cover.

Description

Technical Field

[0001] This utility model relates to an air fryer, specifically a high-efficiency back-blowing air fryer. Background Technology

[0002] An air fryer is a new type of household appliance that uses high-speed air circulation technology to fry food. Compared to traditional electric fryers, it reduces oil content by up to 80%, is easy to clean, and is both safe and economical, making it very popular. Current air fryers primarily use two types of heating elements for energy transfer: 1. Air fryers with metal tube heating elements: Energy transfer within the air fryer is mainly through forced convection. The intensity of convection directly determines the product's energy efficiency and heat exchange rate; therefore, the strength of convection determines the air fryer's performance. 2. Air fryers with carbon tube or graphene tube heating elements: Energy transfer within the air fryer involves a ratio of radiation to forced convection energy of approximately 1:1, making fluid intensity still very important. Some existing air fryers overcome the above problems by using hot air from the back, such as application number 202410837162.4 disclosed in Chinese patent literature, application publication date 2024.08.23, invention title "Air Fryer with Back Air Exit"; and application number 202510171095.1 disclosed in Chinese patent literature, application publication date 2025.03.28, invention title "A Multi-Channel Air Fryer". However, the traditional air fryers with hot air from the back, as mentioned above and similar products, have low fluid energy efficiency and still have the following problems: 1. In air fryers with back air exit, a large amount of fluid is thrown out by the centrifugal fan and hits the air fryer wall, resulting in serious loss of fluid kinetic energy and low energy efficiency; 2. The impeller and hot air duct are not properly matched, which causes large turbulence in the hot air duct, resulting in large fluid energy loss and chaotic flow that does not act on the food. Summary of the Invention

[0003] To overcome the aforementioned shortcomings, the purpose of this utility model is to provide a high-efficiency back-blowing air fryer, thereby solving the technical problems of low fluid energy efficiency and large turbulence in existing similar products, resulting in significant fluid energy loss and chaotic flow that fails to reach the food. This objective is achieved through the following technical solution.

[0004] A high-efficiency back-blowing air fryer includes a metal heat insulation cover inside the air fryer's body. The inner diameter of one side opening of the body is covered by the metal heat insulation cover to form a metal heat insulation layer. A hot air mechanism with impellers and a heat dissipation mechanism are sequentially arranged on the back of the metal heat insulation cover. The key structural design features that the hot air mechanism and heat dissipation mechanism on the back of the metal heat insulation cover are angled towards the bottom of the body. A rectangular groove in the middle of the back of the metal heat insulation cover has equidistant internal through holes on its inner plane. The groove protrudes triangularly towards the back, and the hot air impeller, heating pipe, and heat dissipation impeller within the hot air mechanism and heat dissipation mechanism are parallel to each other. The circumferential surface of the groove of the metal heat insulation cover is aligned with the hot air impellers inside the heat insulation guide shroud of the hot air mechanism. The impeller surfaces at the wheel are spaced 4-5mm apart. The outer sides and bottom plane of the groove of the metal heat shield are provided with equally spaced external through holes. The inner and outer through holes of the metal heat shield are sealed to the lower opening of the heat insulation guide shroud of the hot air mechanism on the back of the metal heat shield. The upper through hole above the groove of the metal heat shield is connected to and sealed with the upper opening of the heat insulation guide shroud. The upper through hole is located on one side of the protruding cavity at the top of the metal heat shield above the pot opening of the inner pot of the fryer assembly. The inner through hole in the groove of the metal heat shield is aligned with the pot through holes evenly distributed on the back of the inner pot. The outer through hole in the groove of the metal heat shield is aligned with the chamfered edges on both sides of the pot through holes on the back of the inner pot. The exhaust hole on at least one side of the air guide and collector shroud of the heat dissipation mechanism is aligned with and connected to the mesh of the machine body. The thickness of the aforementioned enclosure surface and impeller surface should ideally be controlled between 4-5mm. Excessive thickness can easily generate large turbulence, while insufficient thickness will produce significant aerodynamic noise. Simultaneously, the groove in the metal heat shield forms an obliquely oriented triangular protrusion, parallel to the hot air impeller, heating pipe, and cooling impeller. Furthermore, the hot air impeller and heating pipe are also designed with an oblique angle, with the angle between them and the vertical groove in the metal heat shield being 1-15 degrees. Additionally, another heating pipe can be installed in the protruding cavity at the top of the metal heat shield as needed.

[0005] The heat insulation guide shroud has symmetrical triangular chamfers on both sides of its upper through-hole. The functions of these chamfers are as follows: to guide the flow, allowing the fluid to turn in advance for better exit from the hot air system; and to suppress turbulence, compressing the fluid's movement space within the hot air system and suppressing the possibility of large turbulence.

[0006] The airflow collector is located on the back of the heat-insulating airflow collector. The drive shaft of the motor on the back of the airflow collector passes through both the airflow collector and the heat-insulating airflow collector, and is simultaneously connected to the heat dissipation impeller inside the airflow collector and the hot air impeller inside the heat-insulating airflow collector. The hot air impeller is located inside the heating tube within the inner diameter of the heat-insulating airflow collector. The heating tube and the motor are connected to the control circuit board via wiring. The heat dissipation impeller is a plastic cross-flow fan blade, and the hot air impeller is a multi-bladed radial centrifugal impeller. The heating tube is positioned near the hot air impeller, and the circumference of the hot air impeller is where the fluid intensity inside the air fryer is highest, thus maximizing the energy generated by the heating tube into the cavity.

[0007] The heat insulation shroud contains a square-shaped groove for the heating pipes and hot air impeller. The heating pipes are mounted within the groove of the shroud via supports, and are wound around the shroud in a square pattern. The winding of the heating pipes is spaced 2-3 mm apart by supports. This design increases fluid velocity when it encounters obstruction, and the greater the fluid velocity, the smaller the turbulence. Maintaining a 2-3 mm gap between the heating pipes is crucial; too small a gap hinders fluid flow, while too large a gap fails to accelerate the fluid. An optimal gap is 2.4 mm.

[0008] The metal heat insulation cover includes a metal heat insulation liner, a metal heat insulation top cover, and a metal heat insulation bottom plate. One end of the front of the protruding cavity at the top of the metal heat insulation top cover is bent downwards. The protruding cavity at the top of the metal heat insulation top cover is aligned with the inner diameter of the pot opening of the inner pot of the lower fryer assembly. The back opening at the other end of the protruding cavity at the top of the metal heat insulation top cover is integrated with the opening of the heat insulation guide cover. The outer side of the opening of the top opening of the metal heat insulation liner at the protruding cavity at the top of the metal heat insulation top cover is integrated with the outer side of the cavity opening. The bottom opening of the metal heat insulation liner is integrated with the metal heat insulation bottom plate. The groove, inner through hole, and outer through hole are respectively provided on the back of the metal heat insulation liner. The metal heat insulation liner at the upper through hole formed by the metal heat insulation liner, the metal heat insulation top cover, and the heat insulation guide cover has a through hole edge protruding towards the opening side of the machine body. The through hole edge is higher than the pot opening of the inner pot of the lower fryer assembly. The structural design of the aforementioned metal heat-insulating top cover improves the airflow effect at the upper through-hole between the metal heat-insulating liner and the metal heat-insulating top cover.

[0009] The inner through holes in the groove of the metal heat insulation liner are arranged in a rectangular or square shape at equal intervals from the center outwards. The inner through holes are respectively shaped like right-angled trapezoids. The outer through holes are distributed at equal intervals around the outer sides and bottom plane of the groove and are respectively shaped like waists. The purpose of maximizing the arrangement of the inner and outer through holes is the same as the purpose of the chamfered corners of the heat insulation guide shroud, which is to guide the flow and suppress large-diameter turbulence.

[0010] The metal heat insulation cover, which consists of a metal heat insulation liner, a metal heat insulation top cover, and a metal heat insulation bottom plate, has a metal sealing plate at one side of the opening that is integrated with and seals the opening on one side of the machine body. The metal sealing plate is integrated with the opening of the machine body.

[0011] The metal heat-insulating base plate at the bottom of the machine body has two parallel stamping grooves, and the stamping ribs at the bottom of the inner pot of the fryer assembly are inserted into the opening on one side of the machine body, corresponding to the stamping grooves of the metal heat-insulating base plate.

[0012] The inner wall of the top protrusion of the metal heat-insulating top cover is provided with three equidistant, stamped air guides. The middle air guide is located towards the front of the opening side of the body, and the air guides increase in size and height from the opening side of the body towards the back, forming a triangle. This air guide further improves the air guiding effect at the upper through-hole between the metal heat-insulating liner and the metal heat-insulating top cover.

[0013] An NTC temperature sensor is inserted into the protruding cavity at the top of the metal heat-insulating top cover. The NTC temperature sensor is connected to the control circuit board via wiring.

[0014] The front of the metal heat-insulating top cover, which curves downwards, has a through-hole. This through-hole aligns with and communicates with the heat dissipation holes on the fryer assembly's cover. The lower heat dissipation holes on the fryer assembly's cover align with and communicate with the through-hole on the bottom plate of the metal heat-insulating base plate inside the machine body at the bottom of the opening. This structure further improves heat dissipation within the machine body and enhances the ventilation effect of the cooling system.

[0015] This utility model has a reasonable structural design and is easy to manufacture and assemble. In particular, it suppresses the generation of large turbulence, improves the fluid energy efficiency of the product, and thus improves the performance of the air fryer. It is suitable for use as a high-efficiency back-blowing air fryer and for structural improvements of similar products. Attached Figure Description

[0016] Figure 1 This is a cross-sectional structural diagram of an embodiment of the present invention, with part A defined in the diagram.

[0017] Figure 2 yes Figure 1 Enlarged view of part A.

[0018] Figure 3 yes Figure 1 A schematic diagram of the internal rear structure of the machine body, omitting the outer shell of the machine body.

[0019] Figure 4 yes Figure 3 The diagram shows the structure of the metal heat-insulating top cover inside the fryer after the fryer components are removed. The dotted lines in the diagram represent the internal metal heat-insulating lining and the back structure, while the metal heat-insulating bottom plate is omitted.

[0020] Figure 5 yes Figure 4 A schematic diagram of the metal heat-insulating inner lining is shown, omitting the metal heat-insulating top cover and the outer shell of the machine body.

[0021] Figure 6 yes Figure 5 The diagram shows the structure of the fryer assembly after it is placed inside; the back component with the metal heat-insulating liner is omitted from the diagram.

[0022] Figure 7 yes Figure 3Enlarged structural diagram of the heat insulation shroud and airflow collector shroud at the back.

[0023] Figure 8 yes Figure 7 A frontal view of the structure.

[0024] Figure 9 yes Figure 8 A schematic diagram of the three-dimensional structure of the heating element.

[0025] Figure 10 yes Figure 9 A top view of the heating element structure.

[0026] Attached Figures and Their Names: 1. Heat Insulation Diffuser, 101. Chamfer, 2. Heating Tube, 3. Hot Air Impeller, 4. Motor, 5. Heat Dissipation Impeller, 6. Airflow Diffuser, 7. Metal Heat Insulation Liner, 701. Groove, 702. Inner Through Hole, 703. Outer Through Hole, 704. Through Hole Edge, 8. Metal Heat Insulation Top Cover, 801. Extension Edge, 802. Air Guide Platform, 9. Fryer Assembly, 901. Inner Pot, 10. Metal Heat Insulation Base Plate, 1001. Stamping Groove, 11. NTC Temperature Sensor, 12. Metal Sealing Plate, 13. Bracket. Implementation

[0027] The structure and use of this utility model will now be further described with reference to the accompanying drawings. Figures 1-10 As shown, the air fryer has a metal heat insulation cover inside its body. The inner diameter of the opening on one side of the body is covered by the metal heat insulation cover to form a metal heat insulation layer. A hot air mechanism with an impeller and a heat dissipation mechanism are sequentially arranged on the back of the metal heat insulation cover. The hot air mechanism and heat dissipation mechanism on the back of the metal heat insulation cover are angled towards the bottom of the body. The groove 701 in the middle of the back of the metal heat insulation cover is rectangular. The inner plane of the groove has equidistant internal through holes 702. The groove of the metal heat insulation cover protrudes triangularly towards the back, parallel to the hot air impeller 3, heating pipe 2, and heat dissipation impeller 5 within the hot air mechanism and heat dissipation mechanism. The surface of the metal heat insulation cover's groove enclosure is perpendicular to the impeller surface of the hot air impeller inside the heat insulation guide shroud 1 of the hot air mechanism. With a spacing of 4-5mm, the outer sides and bottom plane of the groove of the metal heat insulation cover are provided with equally spaced external through holes 703. The internal and external through holes of the metal heat insulation cover are sealed to the lower opening of the heat insulation guide hood of the hot air mechanism on the back of the metal heat insulation cover. The upper through hole above the groove of the metal heat insulation cover is connected to and sealed with the upper opening of the heat insulation guide hood. The upper through hole is located on one side of the protruding cavity at the top of the metal heat insulation cover above the pot opening of the inner pot 901 of the fryer assembly 9. The internal through hole in the groove of the metal heat insulation cover is aligned with the pot through holes evenly distributed on the back of the inner pot. The external through hole in the groove of the metal heat insulation cover is aligned with the chamfered edges on both sides of the pot through holes on the back of the inner pot. The exhaust hole on at least one side of the air guide and collection cover 6 of the heat dissipation mechanism is aligned with and connected to the mesh of the machine body.

[0028] Its specific structure is as follows: The upper through-hole of the aforementioned heat-insulating guide shroud has symmetrically arranged triangular chamfers 101 on both sides of its back end corner; the air guide shroud is located on the back of the heat-insulating guide shroud, and the drive shaft of the motor 4 on the back of the air guide shroud passes through the air guide shroud and the heat-insulating guide shroud, and is simultaneously connected to the heat dissipation impeller inside the air guide shroud and the hot air impeller inside the heat-insulating guide shroud. The hot air impeller is located inside the heating pipe within the inner diameter of the heat-insulating guide shroud, and the heating pipe and motor are connected to the control circuit board via wiring; the heat dissipation impeller is a plastic cross-flow fan blade, and the hot air impeller is a multi-bladed radial centrifugal impeller. The shroud groove inside the heat-insulating guide shroud containing the heating pipe and the hot air impeller is square. The heating pipe is set within the shroud groove of the heat-insulating guide shroud via a bracket 13, and the heating pipe is wound in a square pattern corresponding to the shroud groove of the heat-insulating guide shroud. The winding of the heating pipe is spaced 2-3 mm apart by the bracket and the pipe fittings.

[0029] The aforementioned metal heat insulation cover includes a metal heat insulation liner 7, a metal heat insulation top cover 8, and a metal heat insulation bottom plate 10. One end of the front of the protruding cavity at the top of the metal heat insulation top cover of the metal heat insulation liner is bent downwards. The protruding cavity at the top of the metal heat insulation top cover is aligned with the inner diameter of the pot opening of the inner pot of the lower fryer assembly. The back opening at the other end of the protruding cavity at the top of the metal heat insulation top cover is integrated with the opening of the heat insulation guide cover. The outer extension edge 801 of the top opening of the metal heat insulation liner and the protruding cavity at the top of the metal heat insulation top cover is integrated. The bottom opening of the metal heat insulation liner is integrated with the metal heat insulation bottom plate. The groove, inner through hole, and outer through hole are respectively provided on the back of the metal heat insulation liner. The metal heat insulation liner at the upper through hole formed between the metal heat insulation liner, the metal heat insulation top cover, and the heat insulation guide cover has a through hole edge 704 protruding towards the opening side of the machine body. The through hole edge is higher than the pot opening of the inner pot of the lower fryer assembly. The inner through holes in the groove of the metal heat-insulating liner are arranged in a rectangular or square shape at equal intervals from the center outwards. The inner through holes are respectively right-angled trapezoids. The outer through holes are distributed at equal intervals around the outer sides and bottom plane of the groove and are respectively waist-shaped. The metal heat-insulating cover, which is composed of the metal heat-insulating liner, the metal heat-insulating top cover, and the metal heat-insulating bottom plate, has a metal sealing plate 12 at one side of the opening that is integrated with and seals the opening on one side of the machine body. The metal sealing plate is integrated with the opening on the machine body. The metal heat-insulating bottom plate at the bottom of the machine body has two parallel stamping grooves 1001. The stamping ribs at the bottom of the inner pot of the fryer assembly are inserted into the opening on one side of the machine body, corresponding to the stamping grooves of the metal heat-insulating bottom plate. The inner wall of the top protrusion of the metal heat-insulating top cover is provided with three equally spaced and stamped air guides 802. The middle air guide is located at the front of the opening side of the body. The air guides increase in size and height from the opening side of the body towards the back, forming a triangle. An NTC temperature sensor 11 is inserted into the cavity of the top protrusion of the metal heat-insulating top cover. The NTC temperature sensor is connected to the control circuit board through a circuit.

[0030] To use, remove the fryer assembly, place food in the inner pot of the fryer assembly, or place food on the rack in the inner pot. Put the fryer assembly back into the machine, then press the button on the control panel of the air fryer to cook the food.

[0031] Based on the above structural features, the front part of the metal heat-insulating top cover can be further provided with a through hole on the top cover, which is aligned and communicates with the heat dissipation hole on the cover of the fryer assembly. The lower heat dissipation hole on the cover of the fryer assembly is aligned and communicates with the through hole on the bottom plate of the metal heat-insulating bottom plate at the bottom of the machine body opening, thereby further improving the heat dissipation effect of the internal cold air system; and the through hole edge of the metal heat-insulating liner can be extended as a guide plate.

Claims

1. A high-efficiency back-blowing air fryer, wherein the air fryer body is provided with a metal heat insulation cover, the inner diameter of the opening on one side of the body is covered by the metal heat insulation cover to form a metal heat insulation layer, and the back of the metal heat insulation cover is provided with a hot air mechanism with an impeller and a heat dissipation mechanism in sequence; characterized in that The hot air mechanism and heat dissipation mechanism on the back of the metal heat shield are inclined towards the bottom of the machine body. The groove (701) in the middle of the back of the metal heat shield is rectangular. The inner plane of the groove of the metal heat shield is provided with equidistant inner through holes (702). The groove of the metal heat shield protrudes triangularly towards the back and is parallel to the hot air impeller (3), heating pipe (2), and heat dissipation impeller (5) in the hot air mechanism and heat dissipation mechanism. The side plate of the groove of the metal heat shield is 4-5mm away from the impeller surface of the hot air impeller in the heat insulation guide shroud (1) of the hot air mechanism. The outer sides and bottom plane of the groove of the metal heat shield are respectively provided with equidistant outer through holes. The inner and outer through holes of the metal heat shield (703) are sealed to the lower opening of the heat insulation guide hood of the hot air mechanism on the back of the metal heat shield. The upper through hole above the groove of the metal heat shield is connected to and sealed with the upper opening of the heat insulation guide hood. The upper through hole is located on one side of the protruding cavity at the top of the metal heat shield above the pot opening of the inner pot (901) of the fryer assembly (9). The inner through hole in the groove of the metal heat shield is aligned with the pot through holes distributed at equal intervals on the back of the inner pot. The outer through hole in the groove of the metal heat shield is aligned with the chamfered edges on both sides of the pot through holes on the back of the inner pot. The exhaust hole on at least one side of the air guide hood (6) of the heat dissipation mechanism is aligned with and connected to the mesh of the machine body.

2. The high-efficiency back-blowing air fryer according to claim 1, characterized in that... The heat insulation guide hood (1) has symmetrical triangular chamfers (101) on both sides of the back corner of the upper through hole.

3. The high-efficiency back-blowing air fryer according to claim 1, characterized in that... The air guide shroud (6) is located on the back of the heat insulation shroud (1). The drive shaft of the motor (4) on the back of the air guide shroud passes through the air guide shroud and the heat insulation shroud, and is connected to the heat dissipation impeller (5) inside the air guide shroud and the hot air impeller (3) inside the heat insulation shroud. The hot air impeller is located inside the heating pipe (2) in the inner diameter of the heat insulation shroud. The heating pipe and the motor are connected to the control circuit board through the wiring. The heat dissipation impeller is a plastic cross-flow fan blade, and the hot air impeller is a multi-bladed radial centrifugal impeller.

4. The high-efficiency back-blowing air fryer according to claim 3, characterized in that... The heat insulation guide hood (1) is provided with a square groove for heating pipe (2) and hot air impeller (3). The heating pipe is set in the inner diameter of the groove of the heat insulation guide hood through the bracket (13). The heating pipe is wound in a square shape corresponding to the groove of the heat insulation guide hood. The winding part of the heating pipe is spaced 2-3mm apart by the bracket and the pipe fittings.

5. The high-efficiency back-blowing air fryer according to claim 1, characterized in that... The metal heat insulation cover includes a metal heat insulation liner (7), a metal heat insulation top cover (8), and a metal heat insulation base plate (10). One end of the front of the protruding cavity at the top of the metal heat insulation top cover of the metal heat insulation liner is bent downward. The protruding cavity at the top of the metal heat insulation top cover is aligned with the inner diameter of the pot opening (901) of the inner pot of the lower fryer assembly (9). The back opening at the other end of the protruding cavity at the top of the metal heat insulation top cover is integrated with the opening of the heat insulation guide hood (1). The top opening of the metal heat insulation liner is connected to the metal heat insulation top cover. The outer side extension edge (801) of the cavity opening at the top of the cover is integrated, and the bottom cover opening of the metal heat insulation liner is integrated with the metal heat insulation base plate. The groove (701), the inner through hole (702), and the outer through hole (703) are respectively provided on the back of the metal heat insulation liner. The metal heat insulation liner at the upper through hole formed between the metal heat insulation liner, the metal heat insulation top cover, and the heat insulation guide cover is provided with a through hole edge (704) protruding towards the opening side of the machine body. The through hole edge is higher than the pot opening of the inner pot of the lower fryer assembly.

6. The high-efficiency back-blowing air fryer according to claim 5, characterized in that... The inner through holes (702) in the groove (701) of the metal heat insulation liner (7) are arranged in a rectangular or square shape at equal intervals from the center outwards. The inner through holes are respectively in the shape of right trapezoids. The outer through holes (703) are distributed at equal intervals around the outer sides and bottom plane of the groove and are respectively in the shape of waist.

7. The high-efficiency back-blowing air fryer according to claim 5, characterized in that... The metal heat insulation cover, which consists of the metal heat insulation liner (7), the metal heat insulation top cover (8) and the metal heat insulation bottom plate (10), has a metal sealing plate (12) at one side of the opening that is integrated with and seals the opening on one side of the machine body. The metal sealing plate is integrated with the opening of the machine body.

8. The high-efficiency back-blowing air fryer according to claim 5, characterized in that... The metal heat-insulating base plate (10) at the bottom of the machine body is provided with two parallel stamping grooves (1001). The bottom stamping rib of the inner pot (901) of the fryer assembly (9) is inserted into the opening on one side of the machine body, corresponding to the stamping groove of the metal heat-insulating base plate.

9. The high-efficiency back-blowing air fryer according to claim 5, characterized in that... The inner wall of the top protrusion of the metal heat-insulating top cover (8) is provided with three equally spaced and stamped air guides (802). The middle air guide is close to the front of the opening side of the body. The air guides increase in size and height from the opening side of the body to the back, forming a triangle.

10. The high-efficiency back-blowing air fryer according to claim 5, characterized in that... The metal heat-insulating top cover (8) has an NTC temperature sensor (11) inserted into the protruding cavity on top. The NTC temperature sensor is connected to the control circuit board via a circuit.

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