Centrifugal impeller and air fryer thereof

Abstract

The utility model relates to a centrifugal impeller and an air fryer thereof. The centrifugal impeller and the air fryer are designed to solve the technical problems that due to the fact that fan blade structures of existing similar products are not good enough, uniformity of a wind field and a temperature field is poor, the cooking effect is poor, and the baking qualification rate is low. A body of the centrifugal impeller is a special-shaped inclined fan blade, inclined partition plates distributed at equal intervals are arranged on the circumferential face between a ring plate and a disc plate of the special-shaped inclined fan blade, and the special-shaped inclined fan blade is a cross-flow fan blade. The special-shaped inclined fan blade is characterized in that a disc plate on the inner side of the lower portion of a ring plate of the special-shaped inclined fan blade is formed in an outward stamping and protruding mode, and the included angle between the inclined face of the disc plate below the ring plate and the horizontal bottom face of the stamping and protruding portion on the inner side of the disc plate ranges from 120 degrees to 160 degrees, and optimally, the included angle is 153 degrees; the special-shaped inclined fan blade with the structure is applied to the air fryer with air discharged from the back for heating, is arranged in the back heat insulation cover and is used as air circulation of the hot air channel in the cavity, and the air circulation of the cold air channel utilizes the stirring fan blade at the rear part of the special-shaped inclined fan blade.

Description

Technical Field

[0001] The utility model relates to an impeller of an air fryer, in particular to a centrifugal impeller and an air fryer thereof. Background Art

[0002] An air fryer is a new type of household appliance that uses high-speed air circulation technology to fry food. The food it makes can reduce 80% of the fat compared to traditional electric fryers. It is easy to clean in daily use, safe and economical, and is favored by people. At present, the centrifugal impellers with cross-flow fan blades in some air fryers on the market have the following technical problems: the existing air fryer structure with a hot air system on the top uses a centrifugal impeller, which is easy to make the product forehead high. When making a vertical double-pot air fryer, the overall height of the product will be too high, and the centrifugal impeller is not suitable for the vertical double-pot form; at the same time, the performance of the back-blown air fryers on the market generally cannot reach the effect of traditional air fryers, which is mainly reflected in the poor uniformity of the wind field and temperature field; and the traditional back-blown air fryer generally sets the heating tube on the back. In terms of the baking effect of French fries, the baking pass rate of 400g French fries is less than 60%, the French fries near the handle are excessively browned, and the French fries on the side away from the handle are basically not browned, indicating that the energy distribution in the pot is uneven. In order to overcome the above-mentioned partial cooking of French fries, and the problems of uniformity of wind field and temperature field, some existing back-blown air fryers have another heating tube arranged in a groove on the top of the body above the pot body, such as the application number 202410614755.4 disclosed in the Chinese patent literature, the application publication date 2024.07.12, and the invention name "A back-blown air fryer and control method"; however, the hardware fan blades of the above-mentioned products and similar products mainly adopt the structural design of stirring fan blades, and some similar products that adopt cross-flow fan blades still have problems with uniformity of wind field and temperature field, and the thermal efficiency of the product needs to be further improved. Summary of the invention

[0003] In order to overcome the above shortcomings, the purpose of the utility model is to provide a centrifugal impeller and an air fryer in the art, so as to solve the technical problems of the existing similar products, such as poor impeller structure design leading to poor uniformity of wind field and temperature field, poor cooking effect and low baking qualification rate. The purpose is achieved through the following technical solutions.

[0004] A centrifugal impeller, the body of which is a special-shaped inclined airfoil. At the circumferential surface between the ring plate and the disk plate of the special-shaped inclined airfoil, equally spaced inclined partition plates are provided. The lug ears at both ends of the inclined partition plates are respectively inserted into the plate holes of the ring plate and the disk plate and then bent and fixed into one body. A shaft-passing hole is provided at the center of the disk plate. The special-shaped inclined airfoil is a cross-flow airfoil. The key point of the structural design is that the disk plate on the inner side below the ring plate of the special-shaped inclined airfoil is formed by outward stamping and bulging. The included angle between the inclined surface at the disk plate under the ring plate and the horizontal bottom surface of the stamping bulge on the inner side of the disk plate is 120 degrees - 160 degrees, and preferably 153 degrees. The above structure facilitates the generation of spiral air vortices at the rear of the special-shaped inclined airfoil, thereby improving the uniformity of the air field and temperature field in the cavity during the air outlet and inlet processes.

[0005] At the horizontal bottom surface of the stamping bulge on the inner side of the disk plate of the special-shaped inclined airfoil, equally spaced stamping grooves are provided. For the above special-shaped inclined airfoil, in addition to the stamping grooves on the disk plate, other hole positions convenient for component installation can also be set as needed.

[0006] According to the structural characteristics of the above special-shaped inclined airfoil, taking an air fryer with back air outlet heating as an example; the inner liner of the housing of the air fryer includes a metal inner liner and a metal heat shield on the top of the metal inner liner. A heating tube is provided in the groove of the metal heat shield above the top of the metal inner liner. One side through holes of the special-shaped inclined airfoil in the housing of the metal inner liner include a main air outlet hole, an air inlet hole, and an auxiliary air outlet hole. The main air outlet hole is aligned and communicated with the opening on one side of the groove of the metal heat shield. The other side of the groove of the metal heat shield is arranged opposite to the inner wall of one side of the inner pot of the lower pot body assembly through a curved surface. The air inlet hole is arranged in the middle of the metal inner liner below the main air outlet hole. The auxiliary air outlet hole is arranged in the metal inner liner below the air inlet hole. A pot body assembly is provided at the opening on one side of the metal inner liner. The handle of the pot body assembly extends out of the opening of the metal inner liner. Equally spaced pot holes are provided on the back of the inner pot of the pot body assembly on the symmetric other side of the opening of the metal inner liner. A back heat shield is provided in the rear housing of the metal inner liner at the main air outlet hole opposite to the pot holes. The special-shaped inclined airfoil is arranged in the back heat shield. The stirring airfoil is arranged in the motor bracket behind the back heat shield. Hollow holes communicating with the cold air channel between the outer diameter of the back heat shield and the inner side of the housing are provided on both sides and one rear plane of the motor bracket. A shaded pole motor is provided at the rear of the motor bracket. The rotating shaft of the shaded pole motor is connected to the stirring airfoil and the special-shaped inclined airfoil at the same time. The shaded pole motor and the heating tube are connected to the PCB control assembly through wires. The above stirring airfoil is a hardware airfoil. The above heating tube is a serpentine tube or a carbon tube. In order to facilitate the installation of the heating tube, a hoop mounting position is provided in the middle or other positions of the top of the corresponding metal heat shield. The stirring airfoil is mainly used for air circulation in the cold air channel, and the special-shaped inclined airfoil is mainly used for air circulation in the hot air channel in the cavity.

[0007] The intake holes of the metal inner liner are circularly arranged between the upper and lower main outlet holes and auxiliary outlet holes. The main outlet holes and the auxiliary outlet holes are respectively rectangular. The width of the auxiliary outlet holes of the metal inner liner is smaller than the width of the main outlet holes, and the diameter at the intake holes is smaller than the width of the auxiliary outlet holes. The above specific structural designs of the main outlet holes, intake holes, and auxiliary outlet holes further ensure the circulation of large and small gases at the upper and lower parts of the cavity, improving the uniformity of the wind field and temperature field.

[0008] On both sides of the intake holes of the metal inner liner, side air holes are symmetrically arranged. The side air holes and the auxiliary outlet holes are arranged in a U shape, and the side air holes are located inside the mouth of the hood at the back heat insulation cover at the rear of the metal inner liner.

[0009] On the curved surface side of the metal heat insulation cover, there is a brim extending forward. The brim, the groove at the curved surface of the metal heat insulation cover, and the two side edges of the groove are integrally formed. At the brim of the above metal heat insulation cover and at the housing of the pot body assembly below the brim, upper air holes are respectively arranged as needed. At the bottom of the housing of the pot body assembly and at the corresponding metal inner liner, lower air holes are respectively arranged as needed.

[0010] On the inner wall of the inner pot at the lower part of the curved surface side of the metal heat insulation cover, there are guide ribs that are equally spaced up and down and protrude; the guide ribs are integrally formed by stamping with the inner pot, or the guide ribs are arranged on a guide member, and the guide member is installed on the inner wall of the inner pot of the pot body assembly.

[0011] On one side of the metal heat insulation cover at the heating tube, there is an NTC temperature sensor extending into the groove. The NTC temperature sensor is connected to the PCB control assembly through a circuit. The setting position of the above NTC temperature sensor is more accurate for temperature sensing.

[0012] The pot hole of the inner pot of the pot body assembly is an inner hexagonal hole, and the pot hole of the inner pot extends from the rear to one end of the two connected rear sides. The shape of the pot hole of the above pot body is not limited to the above inner hexagonal hole.

[0013] The structure of the present utility model is reasonably designed, convenient for production and assembly, has a wide application range, good uniformity of the wind field and temperature field, especially good cooking effect for French fries and good baking qualification rate; it is suitable for use as a centrifugal impeller and its air fryer, especially suitable for use as a centrifugal impeller of an air fryer with rear air outlet heating, and for the structural improvement of similar products. Brief Description of the Drawings

[0014] Figure 1 It is a partial structural schematic diagram of the use state of the present utility model.

[0015] Figure 2 It is Figure 1 the internal structural schematic diagram of

[0016] Figure 3 It isFigure 1 Schematic cross-sectional view of the whole machine in the usage state. The arrows in the figure indicate the large and small gas circulation at the upper and lower parts in the cavity.

[0017] Figure 4 is Figure 1 Schematic layout structure diagram of the through holes at the metal inner lining.

[0018] Figure 5 is Figure 1 Schematic three-dimensional enlarged structure diagram of the special-shaped inclined air blade.

[0019] Figure 6 is Figure 5 Schematic side view structure diagram.

[0020] Figure 7 It is a comparison chart of the calculation results of the simulation cloud diagram and the wind speed histogram between the special-shaped inclined air blade of the present utility model and the existing impeller.

[0021] Appended drawing serial numbers and names: 1. shaded-pole motor, 2. motor bracket, 3. heating tube, 4. metal heat shield, 401. brim, 5. pot body assembly, 501. handle, 502. inner pot, 6. metal inner lining, 601. main air outlet hole, 602. air inlet hole, 603. auxiliary air outlet hole, 604. side air hole, 7. special-shaped inclined air blade, 701. ring plate, 702. disc plate, 703. inclined partition plate, 8. stirring air blade, 9. back heat shield, 10. NTC temperature sensor. Detailed implementation manners

[0022] Now, in combination with the appended drawings, the structure and usage of the present utility model will be further described. As Figures 1-6 shown, the body of the centrifugal impeller is a special-shaped inclined air blade 7. At the circumferential surface between the ring plate 701 and the disc plate 702 of the special-shaped inclined air blade, equally spaced inclined partition plates 703 are provided. The lugs at both ends of the inclined partition plate are respectively inserted into the plate holes of the ring plate and the disc plate and then bent and fixed into one body. A shaft-passing hole is provided at the center of the disc plate. The special-shaped inclined air blade is a cross-flow air blade. At the same time, the disc plate on the inner side below the ring plate of the above-mentioned special-shaped inclined air blade is formed by outward stamping and bulging. The inclined surface at the disc plate below the ring plate and the horizontal bottom surface of the stamping bulge on the inner side of the disc plate form an included angle of 153 degrees. Equally spaced stamping grooves are provided on the horizontal bottom surface of the stamping bulge on the inner side of the disc plate of the special-shaped inclined air blade. Taking four arc-shaped stamping grooves symmetrically arranged in pairs as an example for the stamping grooves of the centrifugal impeller, other shapes can also be adopted.

[0023] The above-mentioned special-shaped inclined air blade is applied to an air fryer with back air outlet heating. The inner liner of the housing of the air fryer includes a metal inner liner 6 and a metal heat shield 4 on the top of the metal inner liner. A heating tube 3 is arranged in a groove of the metal heat shield above the top of the metal inner liner. The through holes on one side of the special-shaped inclined air blade in the housing of the metal inner liner include a main air outlet 601, an air inlet hole 602, and an auxiliary air outlet 603. The main air outlet is aligned and communicated with an opening on one side of the groove of the metal heat shield. The other side of the groove of the metal heat shield is arranged opposite to the inner wall of one side of the inner pot 502 of the lower pot body assembly 5 through a curved surface. The air inlet hole is arranged in the middle of the metal inner liner below the main air outlet. The auxiliary air outlet is arranged in the metal inner liner below the air inlet hole. A pot body assembly is arranged at the opening on one side of the metal inner liner. The handle 501 of the pot body assembly extends out of the opening of the metal inner liner. The back of the inner pot of the pot body assembly symmetrically arranged on the other side of the opening of the metal inner liner is provided with equally spaced pot holes. A back heat shield 9 is arranged in the rear housing of the metal inner liner at the position opposite to the pot holes. A stirring air blade 8 is arranged in the back heat shield. The special-shaped inclined air blade is arranged in the back heat shield. The stirring air blade 8 is arranged in a motor bracket 2 at the rear of the back heat shield. The two sides and one side plane at the rear of the motor bracket are provided with hollow holes communicated with the cold air channel between the outer diameter of the back heat shield and the inner side of the housing. A shaded pole motor 1 is arranged at the rear of the motor bracket. The rotating shaft of the shaded pole motor is connected to the stirring air blade and the special-shaped inclined air blade at the same time. The shaded pole motor and the heating tube are connected to the PCB control assembly through wires. The above-mentioned stirring air blade is a hardware air blade.

[0024] The air inlet hole of the above-mentioned metal inner liner is circular and is arranged in the middle of the upper and lower main air outlets and auxiliary air outlets. The main air outlet and the auxiliary air outlet are respectively rectangular. The width of the auxiliary air outlet of the metal inner liner is smaller than the width of the main air outlet. The diameter at the air inlet hole is smaller than the width of the auxiliary air outlet. Side air holes 604 are symmetrically arranged on both sides of the air inlet hole of the metal inner liner. The side air holes and the auxiliary air outlet are arranged in a U-shaped layout. The side air holes are located inside the cover opening of the back heat shield at the rear of the metal inner liner. A brim 401 extending forward is arranged on one side of the curved surface of the metal heat shield. The brim, the groove on the curved surface of the metal heat shield, and the edges on both sides of the groove are integrally formed. On the inner wall of the inner pot of the pot body assembly below the curved surface of the metal heat shield, guide ribs protruding and equally spaced up and down are arranged; the guide ribs are integrally formed by stamping with the inner pot, or the guide ribs are arranged on a guide member, and the guide member is installed on the inner wall of the inner pot of the pot body assembly. An NTC temperature sensor 10 extending into the groove is arranged on one side of the metal heat shield at the heating tube. The NTC temperature sensor is connected to the PCB control assembly through wires. The pot holes on the inner pot of the pot body assembly are inner hexagonal holes, and the pot holes of the inner pot extend from the rear to one end of the two connected rear sides.

[0025] At the brim of the above-mentioned metal heat shield and at the housing of the pot body assembly below the brim, upper air holes are provided as required. At the bottom of the housing of the pot body assembly and at the corresponding metal inner lining, lower air holes are provided as required; a grill is provided at the bottom of the inner pot as required. The above-mentioned shaded-pole motor, motor bracket, stirring fan blade, back heat shield, and special-shaped inclined fan blade are arranged in the rear cover on the back of the housing, and the rear cover and the housing form the outer shell of the machine body.

[0026] As Figure 7 shown, the wind of the existing impeller in the fluid cloud map hitting the air-frying wall surface in the radial direction of the impeller causes relatively large wind energy loss; after the slope of the main body of the special-shaped inclined fan blade of the present invention is increased, the air outlet is smoother, and it can be seen from the histogram that the wind speed in the cavity increases significantly, and the wind field performance is close to that of a traditional top-air outlet heating air fryer.

[0027] In summary, the special-shaped inclined fan blade of the present invention has the following advantages: 1. Bring the heating energy into the cavity by forced convection; 2. Smoothly send the fluid into the cavity through the diversion structure. At the same time, the above structure improves the uniformity of the temperature field in the air fryer and improves the thermal efficiency; the above-mentioned shaded-pole motor provides power for the stirring fan blade and the special-shaped inclined fan blade, and brings the energy at the heating pipe into the cavity by forced convection, and the energy of the heating pipe is mainly introduced into the cavity in the form of thermal radiation.

Claims

1. A centrifugal impeller, wherein the main body of the centrifugal impeller is a special-shaped oblique fan blade (7), and the circumferential surface between the annular plate (701) and the disc plate (702) of the special-shaped oblique fan blade is provided with oblique partitions (703) distributed at equal intervals, and the lugs at both ends of the oblique partition are respectively inserted into the plate holes of the annular plate and the disc plate and then bent and fixed into one body, and the center of the disc plate is provided with an axial hole, and the special-shaped oblique fan blade is a cross-flow fan blade; characterized in that The disc plate (702) on the inner side below the annular plate (701) of the special-shaped oblique wind blade (7) is formed by outwardly stamping and protruding, and the angle between the inclined surface of the disc plate below the annular plate and the horizontal bottom surface of the stamped protrusion on the inner side of the disc plate is 120 degrees to 160 degrees, and the best angle is 153 degrees.

2. The centrifugal impeller according to claim 1, characterized in that The horizontal bottom surface of the inner side stamping protrusion of the circular plate (702) of the special-shaped oblique wind blade (7) is provided with stamping grooves distributed at equal intervals.

3. An air fryer using the centrifugal impeller according to any one of claims 1 to 2, characterized in that The air fryer has a shell having an inner pot, comprising a metal lining (6) and a metal heat insulation cover (4) on the top of the metal lining. A heating tube (3) is arranged in a groove of the metal heat insulation cover above the top of the metal lining. A through hole on one side of the special-shaped oblique fan blade (7) in the shell of the metal lining comprises a main air outlet (601), an air inlet (602) and an auxiliary air outlet (603). The main air outlet is aligned with and communicates with an opening on one side of the groove of the metal heat insulation cover. The other side of the groove of the metal heat insulation cover is arranged opposite to an inner wall of one side of an inner pot (502) of a pot body assembly (5) below through a curved surface. The air inlet is arranged in the middle of the metal lining below the main air outlet, and the auxiliary air outlet is arranged in the metal lining below the air inlet. The pot body assembly is arranged at an opening on one side of the metal lining. The handle (501) of the pot body assembly extends out of the opening of the metal liner, and the inner pot back of the pot body assembly on the other side of the metal liner opening is symmetrically provided with pot holes distributed at equal intervals. A back heat insulation cover (9) is provided in the rear shell of the metal liner at the main air outlet opposite to the pot hole. The special-shaped oblique fan blade is arranged in the back heat insulation cover. The stirring fan blade (8) is arranged in the motor bracket (2) at the rear of the back heat insulation cover. Hollow holes communicating with the outer diameter of the back heat insulation cover and the cold air channel between the inner side of the shell are provided on both sides and one side plane of the rear of the motor bracket. A shaded pole motor (1) is provided at the rear of the motor bracket. The rotating shaft of the shaded pole motor is connected to the stirring fan blade and the special-shaped oblique fan blade at the same time. The shaded pole motor and the heating tube are connected to the PCB control component through a line. The stirring fan blade is a hardware fan blade.

4. The air fryer according to claim 3, characterized in that The air inlet (602) of the metal liner (6) is circular and arranged between the upper and lower main air outlet (601) and the auxiliary air outlet (603); the main air outlet and the auxiliary air outlet are respectively rectangular; the width of the auxiliary air outlet of the metal liner is smaller than the width of the main air outlet; and the diameter of the air inlet is smaller than the width of the auxiliary air outlet.

5. The air fryer according to claim 4, characterized in that Side air holes (604) are symmetrically arranged on both sides of the air inlet (602) of the metal liner (6), and the side air holes and the auxiliary air outlet holes (603) are arranged in a U shape. The side air holes are located on the inner side of the cover opening at the back heat insulation cover (9) at the rear of the metal liner.

6. The air fryer according to claim 3, characterized in that A brim (401) extending forward is provided on one side of the curved surface of the metal heat insulation cover (4), and the brim is integrally formed with a groove on the curved surface of the metal heat insulation cover and edges on both sides of the groove.

7. The air fryer according to claim 3, characterized in that The inner wall of the inner pot (502) at the pot body assembly (5) below the curved surface of the metal heat insulation cover (4) is provided with equidistantly distributed and raised flow guide ribs; the flow guide ribs are integrally stamped and formed with the inner pot, or the flow guide ribs are provided on a flow guide member, and the flow guide member is installed on the inner wall of the inner pot of the pot body assembly.

8. The air fryer according to claim 3, characterized in that An NTC temperature sensor (10) extending into the groove is provided on one side of the metal heat insulation cover (4) at the heating tube (3), and the NTC temperature sensor is connected to the PCB control component via a line.

9. The air fryer according to claim 3, characterized in that The pot hole at the inner pot (502) of the pot body assembly (5) is a hexagonal hole, and the pot hole of the inner pot extends from the rear to one end of the rear of the two connected sides.

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