Low-noise high-speed air fryer

Abstract

The utility model relates to a low-noise high-speed air fryer, which aims at solving the problems of poor air volume, low air speed, low noise and poor cooking caused by poor structural design of a flow guide cover and corresponding parts above a fryer body of the conventional similar product. The air fryer is characterized in that a groove at a hardware heat insulation cover of the air fryer is round, a turbulence cover is arranged at a notch of the groove of the hardware heat insulation cover, honeycomb-shaped turbulence holes are formed in a cover face of the turbulence cover at equal intervals, a hardware impeller and a heating pipe are arranged in the groove of the hardware heat insulation cover above the turbulence cover, and the groove of the hardware heat insulation cover is in a flat-bottom round bowl shape. The circular bottom surface of the inner bottom of the groove of the hardware heat shield is tangent to the arc-shaped inner wall, the notch of the groove of the hardware heat shield is provided with a vertical groove edge which is 2-5 mm and opens outwards, and the outer side of the plane of the notch of the groove of the hardware heat shield is provided with a step groove which is integrally connected with the metal lining in the opening of the machine body; the hardware impeller is a radial closed impeller, the stirring fan blade is a plastic cross flow heat dissipation impeller, and the heating pipe is a U-shaped heating pipe.

Description

Technical Field

[0001] This utility model relates to an air fryer, specifically a low-noise, high-speed 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 in daily use, and is both safe and economical, making it very popular. Some existing air fryers employ an eccentric design in the structure above the rim to address turbulence issues during cooking, with a grid plate located in the groove below the heating element above the rim. For example, Chinese patent application number 201821352114.2, authorized on August 23, 2019, entitled "An Eccentric Air Fryer," discloses an eccentric design where the central axis of the fryer body is offset from the central axis of the hot air heating element. This creates high-pressure and low-pressure zones within the fryer body when the hot air heating element is activated, generating uneven vortices. Airflows of different intensities and directions cancel each other out, creating turbulence and cyclones within the frying basket and between the food. However, when the aforementioned products and similar products use high-speed motors, the use of high-speed motors in air fryers greatly improves the cooking speed and effect, but at the same time, noise issues also become prominent. Meanwhile, existing air fryers using high-speed motors generate large air volumes and high wind speeds, offering the following advantages: 1. Large air volumes and high wind speeds enhance convective heat transfer, increasing cooking speed; 2. For porous foods: large air volumes and high wind speeds cause rapid evaporation of internal moisture, maintaining a lower surface temperature and allowing the food to form a crust without burning; 3. For meat: large air volumes and high wind speeds cause rapid surface dehydration, resulting in a vigorous Maillard reaction, producing meat that is crispy on the outside and tender on the inside, with a fragrant aroma. However, high-speed motors generate higher noise levels, which increase rapidly with the impeller speed, reaching a high level when the speed exceeds 3500 RPM. Summary of the Invention

[0003] To overcome the aforementioned shortcomings, the purpose of this utility model is to provide a low-noise, high-speed air fryer that solves the technical problems of poor design of the air guide shroud, corresponding impeller, heating tube, and turbulence shroud in existing similar products, resulting in low air volume, low wind speed, high noise, and poor cooking effect. This objective is achieved through the following technical solution.

[0004] A low-noise, high-speed air fryer includes a basket assembly housed within a metal cavity with an opening on one side of the air fryer body. The metal cavity comprises a metal liner, a metal base liner, and a metal heat insulation cover. A metal impeller and a heating element are located within a recessed area of ​​the metal heat insulation cover above the pot opening on the basket assembly. The metal impeller is positioned inside the heating element. The pot opening on the basket assembly is aligned with, or slightly larger than, the groove opening of, the metal heat insulation cover. The top guide shroud contains a stirring fan, and the top of the guide shroud contains a shaded pole motor, which is a high-speed motor. The motor shaft of the shaded pole motor is connected to the metal impeller and the stirring fan. The exhaust port on one side of the turbine-shaped chamber of the guide shroud is connected to the exhaust port on one side of the metal heat insulation cover below, and the exhaust is discharged through the ventilation hole on one side of the machine body. The shaded pole motor and the heating tube are connected to the circuit board and control panel inside the machine body through wiring. The waist-shaped holes equidistantly set on the upper and lower edges of the cover of the pot basket assembly are aligned with the upper and lower holes at the opening of the machine body. The key structural design features a circular groove in the metal heat shield, a turbulence hood at the groove opening, equidistant turbulence holes on the hood surface, a metal impeller and heating tube positioned above the turbulence hood within the groove, a flat-bottomed round bowl-shaped groove, a tangent bottom circular surface to the arc-shaped inner wall of the groove, a 2-5mm outwardly opening vertical groove edge at the groove opening, a stepped groove on the outer side of the groove opening integrated with the metal lining inside the machine body opening, a radially closed impeller, and a flow gap between the outer side of the heating tube and the arc-shaped inner wall of the metal heat shield. This increases the wind speed and air volume of the air fryer during operation by using a high-speed motor, while reducing noise and turbulence and improving cooking results. The aforementioned turbulence hood reduces airflow pulsation by breaking up large-diameter turbulence when the metal impeller draws in air, thus reducing noise.

[0005] A 5-8mm gap L1 is provided between the outer side of the metal impeller inside the metal heat insulation cover and the inner diameter of the heating tube; a 4-6mm gap h1 is provided between the metal impeller and the circular bottom surface of the upper metal heat insulation cover; and a 4-6mm gap h2 is provided between the metal impeller and the lower turbulence shroud. This 5-8mm gap is designed to allow the fluid to flow smoothly through the wall surface. If the 4-6mm gap between the metal impeller and the metal heat insulation cover is too small, it will produce a whistling sound; if it is too large, the fluid will flow into the gap between the metal impeller and the metal heat insulation cover, increasing the noise. Similarly, if the 4-6mm gap between the metal impeller and the turbulence shroud is too small, it will produce a whistling sound; if it is too large, the turbulence capacity will decrease, and the noise will increase.

[0006] The turbulence hood is fixed to the inner diameter of the groove in the metal heat insulation cover via mounting ears that are equidistantly spaced on the outer diameter. A gap L2 of 6-15 mm is provided between the outer diameter of the turbulence hood and the inner diameter of the groove in the metal heat insulation cover. The groove opening at the vertical edge of the metal heat insulation cover transitions outwards to a recessed area via a raised groove platform, the width of which is 4.5-6 mm. The dimensions specified above are controlled between 6-15 mm to ensure smoother fluid flow through the wall surface; dimensions between 4.5-6 mm are also controlled, as larger or smaller sizes will result in significant fluid loss.

[0007] The turbulence hood has equidistant honeycomb-shaped turbulence holes, each a hexagonal hole with a diameter of 6-10 mm and a connecting edge width of 1.5-2 mm. The size of the hexagonal holes is between 6-10 mm; too small a size results in significant fluid dynamic loss, while too large a size leads to insufficient suppression of airflow pulsation. Similarly, the connecting edge size is between 1.5-2 mm; too small a size results in insufficient fluid strength, while too large a size leads to significant fluid loss.

[0008] The diameter of the metal impeller is larger than that of the stirring fan blades, and the diameter of the metal impeller is 124mm. Twelve blades are vertically arranged equidistantly between the circular base plate and the annular plate, centered on the shaft core hole of the circular base plate. The blades are 20mm high and rectangular, with a beveled outer corner near the shaft core hole. The beveled edge of the blade protrudes from the annular plate. The outer diameter of the circular base plate, the outer diameter of the annular plate, and the outer edge of the blades are aligned vertically. The width of the annular plate is smaller than the length of the beveled edge of the blades. The blades are vertically and equidistantly fixed to the corresponding ear holes of the circular base plate and the annular plate by side ears formed by stamping on both sides. The above is a specific structural embodiment of the metal impeller, which further reduces airburst noise by improving the energy efficiency of the metal impeller, reducing the impeller frequency, and decreasing the turbulence size. Simultaneously, the noise frequency is controlled by controlling the diameter of the metal impeller and the number of blades. The use of a radially closed impeller improves the energy efficiency of the metal impeller itself.

[0009] The width of the annular plate at one end of the blade of the metal impeller is less than one-third of the blade length, and the width of the beveled corner at the other end of the blade is less than one-third of the blade length. The height of the lower beveled end is half the blade height, and the distance from one end of the beveled edge of the blade to the shaft core hole of the circular base plate is less than one-third of the blade length. This structure further improves the energy efficiency of the metal impeller and reduces turbulence and noise.

[0010] The agitator impeller is a plastic inertial flow cooling impeller. The outer circumference of the agitator impeller has equidistantly spaced through holes, and one vertical side of the inner diameter has arc-shaped blades. One end of the agitator impeller has a top cover facing the top-mounted shaded motor, while the other end of the agitator impeller has equidistantly spaced trapezoidal chamfered holes. This structure reduces the space occupied by the agitator impeller, further reducing turbulence and noise.

[0011] The heating tube is a U-shaped heating tube, with both ends fixed to the transition grooves on both sides of the lower exhaust port of the metal heat insulation cover. Simultaneously, the heating tube is fixed to the inner side of the arc-shaped inner wall of the metal heat insulation cover using clamps. This heating tube reduces space occupation and facilitates heat flow.

[0012] An NTC temperature sensor is installed inside the groove of the metal heat insulation cover. The NTC temperature sensor is connected to the circuit board and control panel inside the machine via wiring. This allows for real-time monitoring of temperature changes inside the metal heat insulation cover using the NTC temperature sensor.

[0013] The bottom of the pot body of the pot basket assembly has a stamped spiral bottom surface, and a handle is provided on the outside of the pot basket assembly's cover. The transparent viewing window on the cover is aligned with and sealed to a rectangular through hole on one side of the pot body. The aforementioned bottom structure of the pot body further improves the turbulence effect, and the transparent viewing window and its corresponding structure facilitate the observation of the cooking process.

[0014] This utility model has a reasonable structural design, low noise, large air volume, high wind speed, fast cooking speed, and good cooking effect. In particular, when the motor speed exceeds 3500RPM, the noise level is lower than that of similar products. It is suitable for use as a low-noise high-speed air fryer and for structural improvements of similar products. Attached Figure Description

[0015] Figure 1 This is a partial exploded structural diagram of an embodiment of the present invention, in which the pot basket assembly is omitted.

[0016] Figure 2 yes Figure 1 Enlarged internal structure diagram of the metal heat insulation cover.

[0017] Figure 3 yes Figure 1 A magnified front view of the turbulence fairing structure.

[0018] Figure 4 yes Figure 1 A magnified schematic diagram of the hardware impeller structure.

[0019] Figure 5 yes Figure 4 A front view structural diagram of a metal impeller.

[0020] Figure 6 yes Figure 1 A schematic diagram of the assembled 3D structure, omitting the pot basket assembly.

[0021] Figure 7 yes Figure 6 A partial cross-sectional structural diagram.

[0022] Figure 8 yes Figure 7 A schematic diagram of the internal structure of the metal heat insulation cover in its inverted state.

[0023] Figure 9 yes Figure 7 The diagram shows a partial cross-sectional view of the pot basket assembly in its placed state. The dotted line represents the pot body inside the cover of the pot basket assembly, and the framed area has been enlarged.

[0024] Attached Figures and Their Names: 1. Body, 2. Metal Liner, 3. Metal Base, 4. Base, 5. Turbulence Cover, 501. Turbulence Hole, 502. Mounting Ear, 6. Metal Impeller, 601. Inner Circular Bottom Plate, 602. Annular Plate, 603. Blade, 7. Metal Heat Insulation Cover, 701. Circular Bottom Surface, 702. Arc-Shaped Inner Wall, 703. Vertical Slot Edge, 704. Stepped Slot, 705. Slot Platform, 706. Transition Slot, 8. Heating Tube, 9. NTC Temperature Sensor, 10. Stirring Fan, 11. Flow Guide Cover, 12. Shaded Pole Motor, 13. Pot Basket Assembly, 14. Pot Body, 15. Handle, 16. Transparent Viewing Window. Implementation

[0025] The structure and use of this utility model will now be further described with reference to the accompanying drawings. Figures 1-9As shown, the air fryer has a basket assembly 13 located in a metal cavity with an opening on one side of its body 1. The metal cavity includes a metal liner 2, a metal base liner 3, and a metal heat insulation cover 7. The body includes a base 4. A metal impeller 6 and a heating tube 8 are located in the groove of the metal heat insulation cover above the pot opening of the basket assembly's pot body 14. The metal impeller is positioned inside the heating tube. The pot opening of the basket assembly is aligned with or slightly larger than the groove of the upper metal heat insulation cover. The top of the heat shield has a guide shroud 11 with a stirring fan 10 inside. The top of the guide shroud has a shaded pole motor 12, which is a high-speed motor. The motor shaft of the shaded pole motor is connected to the metal impeller and the stirring fan. The exhaust port on one side of the turbine-shaped chamber of the guide shroud is connected to the exhaust port on one side of the metal heat insulation cover below, and the exhaust is discharged through the ventilation hole on one side of the machine body. The shaded pole motor and the heating tube are connected to the circuit board and control panel inside the machine body through wiring. The waist-shaped holes equidistantly arranged on the upper and lower edges of the shell of the pot basket assembly are aligned with the upper and lower holes at the opening of the machine body. The groove of the aforementioned metal heat shield 7 is circular. A turbulence shroud 5 is provided at the groove opening of the metal heat shield. The turbulence shroud has equidistantly spaced turbulence holes 501 on its surface. The metal impeller and heating tube are located within the groove of the metal heat shield above the turbulence shroud. The groove of the metal heat shield is a flat-bottomed, round bowl shape. The circular bottom surface 701 of the groove is tangent to the arc-shaped inner wall 702. The groove opening of the metal heat shield has a 2-5mm outwardly opening vertical groove edge 703, meaning that line 1 at the circular bottom surface and line 2 at the arc-shaped inner wall are tangent. Line 3 at the vertical groove edge is a straight line with a length controlled between 2-5mm. The outer side of the groove opening of the aforementioned metal heat shield has a stepped groove 704 integrated with the metal lining inside the machine body opening. The metal impeller is a radially closed impeller. A flow gap is provided between the outer side of the heating tube and the arc-shaped inner wall of the metal heat shield.

[0026] A 5-8mm gap L1 is provided between the outer side of the metal impeller inside the aforementioned metal heat insulation cover and the inner diameter of the heating tube; a 4-6mm gap h1 is provided between the metal impeller and the circular bottom surface of the upper metal heat insulation cover; and a 4-6mm gap h2 is provided between the metal impeller and the lower turbulence shroud. The turbulence shroud is fixed to the inner diameter of the groove opening in the metal heat insulation cover by mounting ears 502 that are equidistantly arranged on the outer diameter. A 6-15mm gap L2 is provided between the outer diameter of the turbulence shroud and the inner diameter of the groove opening in the metal heat insulation cover. The groove opening at the vertical groove edge of the metal heat insulation cover transitions outward to a recessed area through a raised groove platform 705, the width of which is 4.5-6mm. The turbulence holes of the turbulence shroud are arranged in a honeycomb pattern at equal intervals. The turbulence holes are hexagonal holes with a diameter of 6-10mm and a connecting edge width of 1.5-2mm.

[0027] The diameter of the aforementioned metal impeller is larger than that of the agitator blades. The diameter of the metal impeller is 124mm. Twelve blades 603 are vertically arranged at equal intervals, centered on the shaft core hole of the circular base plate 601 and the annular plate 602 of the metal impeller. The blades are 20mm high and rectangular, with a beveled edge on the outer corner near the shaft core hole. The beveled edge of the blade protrudes from the annular plate. The outer diameter of the circular base plate, the outer diameter of the annular plate, and the outer edge of the blade are aligned vertically. The width of the annular plate is less than the length of the beveled edge of the blade. The blades are vertically and equidistantly fixed to the corresponding ear holes of the circular base plate and the annular plate by side ears formed by stamping on both sides. Simultaneously, the width of the annular plate at one end of the blade is less than one-third of the blade length, and the beveled corner at the other end of the blade is less than one-third of the blade length. The height of the lower beveled end is half the blade height, and the distance from one beveled end of the blade to the shaft core hole of the circular base plate is less than one-third of the blade length.

[0028] The aforementioned stirring fan is a plastic inertial flow cooling impeller. The outer circumference of the stirring fan has equidistantly spaced through holes, and one vertical side of the inner diameter has arc-shaped blades. One end of the stirring fan has a top cover facing the top-mounted shaded motor, while the other end has equidistantly spaced trapezoidal chamfered holes. The heating tube is a U-shaped heating tube, with both ends fixed to the transition grooves 706 on either side of the lower exhaust port of the metal heat insulation cover. Simultaneously, the heating tube is fixed to the inner side of the arc-shaped inner wall of the metal heat insulation cover using clamps.

[0029] An NTC temperature sensor 9 is inserted into one side of the groove in the aforementioned metal heat insulation cover. The NTC temperature sensor is connected to the circuit board and control panel inside the machine via wiring. The bottom of the pot body of the pot basket assembly has a stamped spiral bottom surface. A handle 15 is provided on the outside of the cover of the pot basket assembly. The viewing window 16 provided on the cover is aligned with and sealed to the rectangular through hole on one side of the pot body.

[0030] The noise level of this air fryer decreased by 5.15dB when the rotation speed was increased by 200RPM. To use it, open the basket assembly, put in the food, close and put the basket assembly back in, and press the corresponding button on the control panel. The air fryer will then begin processing the food until it stops. After that, you can remove the basket assembly again to complete the cooking process.

[0031] The above description is intended to illustrate the technical means of this utility model and is not intended to limit the technical scope of this utility model. Any obvious improvements or substitutions made to this utility model by those skilled in the art based on existing common knowledge also fall within the protection scope of the claims of this utility model.

Claims

1. A low-noise, high-speed air fryer, wherein a basket assembly (13) is provided in a metal cavity with an opening on one side of the air fryer body (1). The metal cavity includes a metal liner (2), a metal bottom liner (3), and a metal heat insulation cover (7). A metal impeller (6) and a heating tube (8) are provided in the groove of the metal heat insulation cover above the pot opening at the pot body (14) of the basket assembly. The metal impeller is located inside the heating tube. The pot opening at the pot body of the basket assembly is aligned with or slightly larger than the groove opening at the groove opening of the metal heat insulation cover. The top of the metal heat insulation cover has a guide shroud (11) with a stirring fan (10) inside. The top of the guide shroud has a shaded pole motor (12). The shaded pole motor is a high-speed motor. The motor shaft of the shaded pole motor is connected to the metal impeller and the stirring fan. The exhaust port on one side of the turbine chamber of the guide shroud is connected to the exhaust port on one side of the lower metal heat insulation cover and discharges into the ventilation hole on one side of the machine body. The shaded pole motor and the heating tube are connected to the circuit board and control panel inside the machine body through wiring. The waist-shaped holes equidistantly arranged on the upper and lower edges of the cover of the pot basket assembly are aligned with the upper and lower holes at the opening of the machine body. The groove of the metal heat shield (7) is circular. A turbulence shield (5) is provided at the groove opening of the metal heat shield. The surface of the turbulence shield is provided with equidistant turbulence holes (501). The metal impeller (6) and the heating tube (8) are located in the groove of the metal heat shield above the turbulence shield. The groove of the metal heat shield is a flat-bottomed round bowl shape. The bottom circular surface (701) of the groove of the metal heat shield is tangent to the arc-shaped inner wall (702). The groove opening of the metal heat shield is provided with a 2-5mm outwardly opening vertical groove edge (703). The outer side of the groove opening of the metal heat shield is provided with a stepped groove (704) that is integrated with the metal lining (2) inside the opening of the body (1). The metal impeller is a radial closed impeller. A flow gap is provided between the outer side of the heating tube and the arc-shaped inner wall of the metal heat shield.

2. The low-noise high-speed air fryer according to claim 1, characterized in that... The metal heat shield (7) has a 5-8mm gap L1 between the outer side of the metal impeller (6) and the inner diameter of the heating tube (8), a 4-6mm gap h1 between the metal impeller and the circular bottom surface (701) of the upper metal heat shield, and a 4-6mm gap h2 between the metal impeller and the lower turbulence shield (5).

3. The low-noise high-speed air fryer according to claim 2, characterized in that... The turbulence hood (5) is fixed to the inner diameter of the groove of the metal heat insulation cover (7) by mounting ears (502) that are equidistantly arranged on the outer diameter and protruding. There is a gap L2 of 6-15 mm between the outer diameter of the turbulence hood and the inner diameter of the groove of the metal heat insulation cover. The groove at the vertical groove edge (703) of the metal heat insulation cover is recessed outward through the protruding groove platform (705). The width of the groove platform is 4.5-6 mm.

4. The low-noise high-speed air fryer according to claim 3, characterized in that... The turbulence holes (501) of the turbulence shroud (5) are arranged in a honeycomb pattern at equal intervals. The turbulence holes are hexagonal holes with a diameter of 6-10 mm and a connecting edge width of 1.5-2 mm.

5. The low-noise high-speed air fryer according to claim 4, characterized in that... The diameter of the metal impeller (6) is larger than the diameter of the stirring fan (10). The diameter of the metal impeller is 124 mm. Twelve blades (603) are provided between the round bottom plate (601) and the annular plate (602) of the metal impeller, which are equidistantly and vertically arranged with the shaft core hole of the round bottom plate as the center. The blades are 20 mm high and rectangular. The outer corner of the blade near the shaft core hole is a bevel. The bevel of the blade protrudes from the annular plate. The outer diameter of the round bottom plate is aligned with the outer diameter of the annular plate and the outer edge of the blade. The width of the annular plate is smaller than the edge length of the bevel of the blade. The blades are fixed vertically to the corresponding ear holes of the round bottom plate and the annular plate by the side ears formed by stamping on both sides.

6. The low-noise high-speed air fryer according to claim 5, characterized in that... The width of the annular plate (602) at one end of the blade of the metal impeller (6) is less than one-third of the blade length, the corner of the inclined side at the other end of the blade is less than one-third of the blade length, the height of the lower inclined end of the inclined side is half of the blade height, and the distance from one end of the inclined side of the blade to the shaft core hole of the round bottom plate (601) is less than one-third of the blade length.

7. The low-noise high-speed air fryer according to claim 1, characterized in that... The stirring fan blade (10) is a plastic inertial flow heat dissipation impeller. The vertical side of the inner diameter of the stirring fan blade is provided with arc-shaped plates, and the top cover of one end of the stirring fan blade faces the top of the shaded pole motor (12). The other end of the stirring fan blade is provided with trapezoidal round chamfered holes arranged at equal intervals.

8. The low-noise high-speed air fryer according to claim 1, characterized in that... The heating tube (8) is a U-shaped heating tube. Both ends of the heating tube are fixed to the transition groove (706) of the groove on both sides of the lower exhaust hole of the metal heat insulation cover (7). At the same time, the heating tube is installed and fixed to the inner side of the arc-shaped inner wall (702) of the metal heat insulation cover by clamping.

9. The low-noise high-speed air fryer according to claim 1, characterized in that... The metal heat shield (7) has an NTC temperature sensor (9) inserted into one side of the groove. The NTC temperature sensor is connected to the circuit board and control panel inside the body (1) via a line.

10. The low-noise high-speed air fryer according to claim 1, characterized in that... The bottom of the pot body (14) of the pot basket assembly (13) is provided with a stamped spiral bottom surface.

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