Air fryer

Abstract

The invention relates to an air fryer which comprises a machine shell, a fryer body and a hot air assembly, a cooking cavity and a mounting cavity located above the cooking cavity are formed in the machine shell, the fryer body is movably assembled in the cooking cavity, and the hot air assembly is used for providing hot air into the fryer body; the air conditioner further comprises a heat dissipation air channel, a cold air fan and a control device, the cold air fan and the control device are arranged in the heat dissipation air channel, the cold air fan is used for sucking external air into the heat dissipation air channel and discharging the external air, and the control device is used for driving the cold air fan and the hot air assembly to work. The heat dissipation air channel comprises an expansion flow channel, a heat absorption flow channel and a contraction flow channel which are sequentially connected in the airflow direction, the flow speed of external air in the expansion flow channel is reduced, the airflow subjected to speed reduction conducts heat exchange in the heat absorption flow channel, the flow speed of the heated airflow in the contraction flow channel is increased, and the heat exchange efficiency is improved. At least part of the accelerated airflow is guided to the outer side surface of the fryer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air fryers, in particular to an air fryer. BACKGROUND

[0002] Air fryers, as a kind of kitchen appliances that use high-speed circulating hot air for cooking, are very popular due to their health and convenience. Among them, air fryers that use transparent glass bowls as cooking containers (hereinafter referred to as "glass bowl air fryers") are more marketable because of their visual cooking process. However, when such products are put on the global market, especially in markets such as Europe and Canada where safety requirements are extremely strict, they face a prominent technical bottleneck: the temperature rise of the product's outer surface is difficult to meet the mandatory requirements of international safety standards (such as IEC 60335).

[0003] Currently, the heat dissipation design of glass bowl air fryers on the market mainly relies on natural convection heat dissipation and limited radiation heat dissipation of the machine shell. The glass pot body itself has poor thermal conductivity, and its outer surface lacks effective forced convection cooling, resulting in the accumulation of heat during cooking and the continuous rise of the pot body's outer surface temperature, which easily exceeds the standard limit. To solve this problem, the common compromise solution is to reduce the heating temperature of the core (i.e., the cooking chamber). However, this directly leads to poor cooking results of hot air circulation, insufficient food coloring, and decreased crispness, and the cooking time is forced to be extended, which seriously affects the core use experience and performance of the product. SUMMARY

[0004] Therefore, it is necessary to provide an air fryer to solve the above problems.

[0005] An air fryer, comprising a machine shell, a fryer, and a hot air assembly, wherein the machine shell is internally provided with a cooking chamber and a mounting chamber located above the cooking chamber, the fryer is movably assembled in the cooking chamber, and the hot air assembly is used to provide hot air into the fryer.

[0006] Further comprising a heat dissipation air duct, a cold air fan arranged in the heat dissipation air duct, and a control device, wherein the cold air fan is used to suck external air into the heat dissipation air duct and discharge it, and the control device is used to drive the cold air fan and the hot air assembly to work.

[0007] The heat dissipation air duct comprises an expansion flow channel, a heat absorption flow channel, and a contraction flow channel connected in sequence along the airflow direction, the external air flow rate decreases in the expansion flow channel, the airflow after speed reduction exchanges heat in the heat absorption flow channel, the heated airflow flow rate increases in the contraction flow channel, and the airflow after speed increase is at least partially guided to the outer surface of the fryer.

[0008] In one of the embodiments, the inner wall of the casing and the fairing located in the mounting cavity form the expansion flow channel; the casing is provided with a first air inlet in communication with the expansion flow channel, the number of the first air inlets is not less than one, the fairing is provided with a first through hole, and the first air inlet, the expansion flow channel and the first through hole are sequentially communicated; the total flow area of the first air inlets is less than the flow area of the first through hole.

[0009] In one of the embodiments, the fairing is connected with the motor cover located in the mounting cavity, and the fairing cover is arranged on the motor cover; the space enclosed by the fairing and the motor cover forms the heat absorption flow channel and the contraction flow channel, and the flow cross-sectional area of the contraction flow channel gradually decreases along the airflow direction.

[0010] In one of the embodiments, the cross section of the contraction flow channel is in the shape of a circular arc.

[0011] In one of the embodiments, the contraction flow channel is arranged downstream of the heat absorption flow channel, and the heat absorption flow channel and the contraction flow channel are distributed circumferentially around the central axis of the first through hole.

[0012] In one of the embodiments, the projection of the heat absorption flow channel and the contraction flow channel on the motor cover is a rectangular area.

[0013] The motor cover is circumferentially divided into a first quadrant, a second quadrant, a third quadrant and a fourth quadrant with the central axis of the first through hole as the center, the control device is distributed in the first quadrant and / or the fourth quadrant, and the motor cover is provided with a flow guide rib at the third quadrant.

[0014] In one of the embodiments, the number of the flow guide ribs is not less than two, the adjacent two flow guide ribs are distributed in the third quadrant, and the distance between the flow guide rib and the rotating shaft of the cold air fan gradually decreases in the rotating direction of the fan blade; and / or, the first air inlets are distributed at one end of the casing side wall close to the control device.

[0015] In one of the embodiments, the air fryer further comprises a reflecting cover arranged in the casing, the reflecting cover is clamped between the cooking cavity and the mounting cavity, and the hot air assembly is located below the reflecting cover.

[0016] In one of the embodiments, the casing comprises an outer shell and an inner liner arranged in the outer shell, the inner liner and the reflecting cover or the motor cover form the cooking cavity, the inner wall of the inner liner and the inner wall of the outer shell form an air guide cavity, and the air guide cavity is in communication with the contraction flow channel.

[0017] In one embodiment, the cooling fan includes a drive motor and a first blade located in the heat absorption channel, and the hot air assembly includes a heating element and a second blade located in the cooking cavity.

[0018] One end of the rotating shaft of the drive motor is connected to the first fan blade, and the other end is connected to the second fan blade.

[0019] One of the above technical solutions has the following advantages and beneficial effects:

[0020] In the aforementioned air fryer, a cooling fan draws outside air into the cooling duct, which then passes through an expansion channel, a heat absorption channel, and a contraction channel. The air is first slowed down in the expansion channel, increasing its static pressure. Subsequently, the airflow enters the heat absorption channel to exchange heat with the waste heat generated by the air fryer. The heated airflow then enters the contraction channel for acceleration. At least part of this accelerated airflow is guided to the outer surface, actively dissipating heat from the outer surface of the fryer and reducing its temperature. Furthermore, it actively converts the waste heat that would otherwise need to be dissipated into power to enhance the cooling airflow. This application, based on the coordination of the cooling fan and the cooling duct, eliminates the need to lower the temperature inside the cooking cavity, ensuring cooking effectiveness and efficiency. It utilizes the waste heat generated by the air fryer to provide active cooling, reducing the temperature of accessible surfaces and avoiding the risk of burns. Attached Figure Description

[0021] Figure 1 A cross-section of an air fryer in one embodiment. Figure 1 ;

[0022] Figure 2 A cross-section of an air fryer in one embodiment. Figure 2 ;

[0023] Figure 3 A cross-section of an air fryer in one embodiment. Figure 3 ;

[0024] Figure 4 A cross-section of an air fryer in one embodiment. Figure 4 ;

[0025] Figure 5 This is a schematic diagram of the structure of an air fryer in one embodiment. Figure 1 ;

[0026] Figure 6 This is a schematic diagram of the structure of an air fryer in one embodiment. Figure 2 .

[0027] The correspondence between the reference numerals and the component names is as follows:

[0028] 10. Housing, 11. Outer shell, 12. Inner liner, 101. Cooking cavity, 102. Mounting cavity, 103. First air inlet, 104. Air guide cavity;

[0029] 20 air fryers;

[0030] 30 Hot air assembly, 31 Heating element, 32 Second fan blade;

[0031] 410 Expansion channel, 420 Heat absorption channel, 430 Contraction channel;

[0032] 50 Cooling fan, 51 Drive motor, 52 First fan blade;

[0033] 60 control devices;

[0034] 70 fairing, 701 first through hole; 80 motor cover, 810 guide rib; 90 reflector. Detailed Implementation

[0035] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0036] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0037] The following describes some embodiments of the air fryer of the present invention with reference to the accompanying drawings.

[0038] like Figures 1 to 6 As shown, this embodiment discloses an air fryer, including a housing 10, an air fryer 20 and a hot air assembly 30. The housing 10 has a cooking cavity 101 and an installation cavity 102 located above the cooking cavity 101. The air fryer 20 is movably assembled in the cooking cavity 101. The hot air assembly 30 is used to provide hot air into the air fryer 20.

[0039] It also includes a heat dissipation duct, a cold air fan 50 and a control device 60 installed in the heat dissipation duct. The cold air fan 50 is used to draw in external air into the heat dissipation duct and exhaust it. The control device 60 is used to drive the cold air fan 50 and the hot air assembly 30 to work.

[0040] The heat dissipation duct includes an expansion channel 410, a heat absorption channel 420, and a contraction channel 430 connected sequentially along the airflow direction. The external air velocity decreases in the expansion channel 410, and the decelerated airflow exchanges heat in the heat absorption channel 420. The heated airflow velocity increases in the contraction channel 430, and the accelerated airflow is at least partially guided to the outer surface of the fryer 20.

[0041] This application discloses an air fryer in which a cooling fan 50 draws external air into a heat dissipation duct, and then sequentially passes through an expansion channel 410, a heat absorption channel 420, and a contraction channel 430. The drawn-in air first slows down in the expansion channel 410, increasing its static pressure. Subsequently, the airflow enters the heat absorption channel 420 to exchange heat with the waste heat generated by the air fryer 20. The heated airflow then enters the contraction channel 430 for acceleration. At least part of the accelerated airflow is guided to the outer surface, which not only actively dissipates heat from the outer surface of the fryer 20, reducing its temperature, but also actively converts the waste heat that would otherwise need to be dissipated into power to enhance the cooling airflow. Based on the cooperation of the cooling fan 50 and the heat dissipation duct, this application eliminates the need to lower the temperature inside the cooking cavity 101, ensuring cooking effect and efficiency. It utilizes the waste heat generated by the air fryer 20 to provide active cooling, reducing the temperature of the accessible surface of the fryer 20 and avoiding the risk of burns.

[0042] The housing 10 serves as the main structural component of the air fryer 20, and its internal space is divided into a cooking cavity 101 and a mounting cavity 102. The cooking cavity 101 can be used to hold the air fryer 20 and the food inside it. The mounting cavity 102 can be used to hold the heat dissipation duct, the cold air fan 50, and the control device 60, etc.

[0043] The hot air assembly 30 can be used to supply the hot air required for cooking to the inside of the fryer 20. The hot air assembly 30 may include a fan and a heating element 31 to generate and circulate the hot air.

[0044] The heat dissipation duct may include an expansion channel 410, a heat absorption channel 420, and a contraction channel 430. The expansion channel 410 may be a channel with an outlet flow cross-sectional area larger than the inlet flow cross-sectional area. The expansion channel 410 can reduce the air velocity drawn in from the outside and increase the static pressure.

[0045] The heat absorption channel 420 can be a site for heat exchange of airflow. After exiting the expansion channel 410, the airflow exchanges heat with the heat generated by the motor, control device 60 or other internal components in the heat absorption channel 420, using the waste heat of the air fryer 20 to form a hot airflow. It should be noted that because the airflow velocity is reduced from the expansion channel 410, the airflow can fully absorb heat. It should also be noted that external air is drawn into the heat dissipation channel and undergoes heat exchange in the heat absorption channel 420. The heat at this time can be one or a combination of the heat generated by electronic components such as the control circuit board and power drive module during operation, the heat generated by the cooling fan 50 during operation, or the heat escaping from the cooking cavity 101 into the mounting cavity 102.

[0046] The contraction channel 430 can be a channel with an outlet flow cross-sectional area smaller than the inlet flow cross-sectional area. Heated airflow enters the contraction channel 430, and according to fluid dynamics principles, the airflow velocity increases significantly due to the acceleration caused by the contraction of the cross-section, thus giving the airflow exiting the contraction channel 430 higher kinetic energy.

[0047] Specifically, external cold air is drawn into the cooling duct. The airflow first passes through the expanding channel 410, entering the heat-absorbing channel 420 at a lower airflow velocity and higher static pressure. In the heat-absorbing channel 420, the airflow exchanges heat with the waste heat generated by the air fryer 20, causing the airflow temperature to rise. Subsequently, it is accelerated out through the contracting channel 430, increasing the velocity at the tail end of the airflow, thereby cooling the surface of the air fryer 20. It should be noted that, according to the law of conservation of mass and the ideal gas law,

[0048] ;

[0049] ;

[0050] in To reduce the static pressure at the outlet of flow channel 430, and It is a constant value. To reduce the airflow temperature at the outlet of channel 430. To reduce the area at the outlet of flow channel 430. To reduce the velocity at the outlet of flow channel 430, we obtain:

[0051] ;

[0052] Assuming that no heat exchange occurs when the airflow enters the heat absorption channel, the airflow temperature at the outlet of the contraction channel 430 is... The unit is K, and the airflow temperature at the outlet of the contraction channel 430 during heat exchange is... Then the wind speed before and after heat exchange satisfies:

[0053] ;

[0054] Right now,

[0055] in, This is the absolute temperature of the airflow at the outlet of the contraction channel 430 when no heat exchange occurs after the airflow enters the heat absorption channel. This refers to the airflow velocity at the outlet of the contraction channel 430 when no heat exchange occurs after the airflow enters the heat absorption channel. The velocity at the outlet of the contraction channel 430 is the airflow velocity when the airflow enters the heat absorption channel and undergoes heat exchange. It can be seen that, while keeping the structure of the contraction channel 430 unchanged, the airflow velocity increases when the airflow undergoes heat exchange and heats up in the heat absorption channel 420 and is discharged through the contraction channel 430.

[0056] The cooling fan 50 can be used as a power source for heat dissipation of the air fryer 20. The cooling fan 50 is used to drive the external air to flow through the expansion channel 410, the heat absorption channel 420 and the contraction channel 430 in sequence.

[0057] The control device 60 can be used to drive the cooling fan 50 and the heating assembly 30. The control device 60 may include a control circuit board and a power drive module. The control circuit board can issue commands according to received instructions or according to a preset program, and supply power to the cooling fan 50, the heating assembly 30, etc. through the power drive module, thereby controlling the start-up, shutdown, power, etc. of the above modules.

[0058] like Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further defines that: the inner wall of the housing 10 and the flow guide 70 located in the mounting cavity 102 enclose and form an expansion flow channel 410;

[0059] The housing 10 has a first air inlet 103 that communicates with the expansion channel 410. There is at least one first air inlet 103. The guide shroud 70 has a first through hole 701. The first air inlet 103, the expansion channel 410 and the first through hole 701 are connected in sequence.

[0060] The total flow area of ​​at least one first air inlet 103 is less than the flow area of ​​the first through hole 701.

[0061] The flow guide 70 is a shell structure with a first through hole 701. The flow guide 70 and the inner wall of the housing 10 cooperate to define the expansion channel 410. For example, the inner wall of the housing 10 is the top wall of the housing 10. The top wall of the housing 10 is reused as a wall surface of the expansion channel 410. The expansion channel 410 is formed by the fixed boundary of the housing 10 and the flow guide 70, without the need for additional independent shells or pipes, thereby improving space utilization and reducing material costs.

[0062] The casing 10 has a first air inlet 103, through which external air enters the expansion channel 410. The position and number of the first air inlets 103 determine the direction and distribution of the incoming air. A first through hole 701 is formed on the guide shroud 70. The first through hole 701 serves as the downstream outlet of the expansion channel 410. External air enters the expansion channel 410 from the first air inlet 103 and is then guided into the heat absorption channel 420 through the first through hole 701. Based on this, it is ensured that external air can only enter through the designated first air inlet 103 and flow according to the designed path, avoiding airflow short circuits or turbulence in this path.

[0063] Since the total flow area of ​​at least one first air inlet 103 is less than the flow area of ​​the first through hole 701, the total air inlet area of ​​the expansion channel 410 is less than the air outlet area of ​​the expansion channel 410, thereby causing the external air to enter the expansion channel 410 to have a reduced flow velocity and increased static pressure.

[0064] like Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the flow guide 70 is connected to the motor cover 80 located in the mounting cavity 102, and the flow guide 70 covers the motor cover 80. The space enclosed by the flow guide 70 and the motor cover 80 forms a heat absorption channel 420 and a contraction channel 430. The flow cross-sectional area of ​​the contraction channel 430 gradually decreases along the airflow direction.

[0065] The motor cover 80 can be a housing structure for mounting the cooling fan 50. The motor cover 80 and the air guide cover 70 can jointly define the heat absorption channel 420 and the contraction channel 430. The heat absorption channel 420 and the contraction channel 430 are integrated into a single cavity formed by the two necessary components, the air guide cover 70 and the motor cover 80, eliminating the need for designing independent and complex pipes and simplifying the structure of the entire heat dissipation duct. It should be noted that one side of the air guide cover 70 is enclosed with the inner wall of the housing 10 to form an expansion channel 410, and the other side is enclosed with the motor cover 80 to form a heat absorption channel 420 and a contraction channel 430. In addition, the space formed by the air guide cover 70 and the motor cover 80 can provide space for the installation of equipment such as the cooling fan 50 and the control device 60, so that the airflow entering the heat dissipation duct can efficiently exchange heat with the waste heat generated by the air fryer 20. Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further defines that the cross-section of the contraction channel 430 is arc-shaped.

[0066] Specifically, the cross-section of the contraction channel 430 is defined as an arc shape. Since the contraction channel 430 is a channel with a gradually decreasing cross-sectional area, when the airflow accelerates in the contraction channel 430, the arc-shaped wall can guide the airflow to turn more smoothly, reduce the eddies and turbulence caused by the separation of the airflow from the wall, and reduce the local resistance and friction loss during the flow process.

[0067] In some embodiments, the contraction channel includes a first contraction section and a second contraction section connected sequentially along the airflow direction; the rate of change of the flow cross-sectional area of ​​the first contraction section is less than that of the second contraction section. Based on this, the initial acceleration phase of the airflow in the first contraction section remains smooth and stable, avoiding eddies and pressure losses caused by abrupt changes in cross-section, thus ensuring efficient energy transfer. In the second contraction section, based on the already stable acceleration of the airflow, a greater degree of convergence is achieved to maximize the outlet velocity and guide the airflow more concentratedly towards the target area.

[0068] like Figure 1 As shown, in addition to the features of the above embodiments, this embodiment further defines that: the shrinkage channel 430 is located downstream of the heat absorption channel 420, and the heat absorption channel 420 and the shrinkage channel 430 are circumferentially distributed around the central axis of the first through hole 701.

[0069] The space enclosed by the guide shroud 70 and the motor cover 80 is divided into a heat absorption channel 420 and a contraction channel 430 along the airflow direction. The airflow discharged from the expansion channel 410 first passes through the heat absorption channel 420 and then is discharged through the contraction channel 430. Since the heat absorption channel 420 is located upstream of the contraction channel 430, the airflow that has been heated and whose density has decreased can immediately enter the contraction channel 430 for accelerated ejection. It should be noted that the control device 60, the cooling fan 50, and other equipment that generate waste heat can be fully configured and installed within the range of the heat absorption channel 420, or can be partially extended into the heat absorption channel 420.

[0070] Based on the circumferential distribution of the heat absorption channel 420 and the contraction channel 430 around the central axis of the first through hole 701, the airflow, after flowing into the first through hole 701, does not flow in only one direction, but diffuses in all directions, evenly passing through the annular heat absorption area, and then merges into the annular contraction channel 430. The circumferential distribution allows the airflow to carry away the heat distributed inside or around the motor cover 80 to a greater extent, avoiding local heat accumulation; at the same time, the high-speed airflow that finally exits from the contraction channel 430 can also act more evenly on the circumferential area of ​​the outer wall of the fryer 20.

[0071] In some embodiments, the cooling fan 50 adopts a centrifugal fan. Based on the air outlet characteristics of the centrifugal fan, which is to radiate outward along the impeller circumference and radial direction, the heat absorption channel 420 and the contraction channel 430 are designed to be circumferentially distributed around the central axis, so that the airflow between the two can be smoothly transitioned, which greatly reduces the loss caused by the impact and eddies due to the abrupt change in flow direction, and improves the working efficiency of the fan and the overall aerodynamic performance of the air duct.

[0072] like Figure 4 As shown, in addition to the features of the above embodiments, this embodiment further defines:

[0073] The projections of the heat absorption channel 420 and the contraction channel 430 onto the motor cover 80 form a rectangular area;

[0074] With the central axis of the first through hole 701 as the center, the motor cover 80 is divided into the first quadrant, the second quadrant, the third quadrant and the fourth quadrant along the circumference;

[0075] The control device 60 is distributed in the first quadrant and / or the fourth quadrant, and the motor cover 80 is provided with a guide rib 810 in the third quadrant.

[0076] The airflow entering the heat absorption channel 420 through the first through-hole 701 faces the impeller of the cooling fan 50 below. The rotating impeller of the cooling fan 50 converts the downward axial airflow into a high-speed radial outflow. This radial outflow sequentially enters the heat absorption channel 420 and the contraction channel 430, which are enclosed by the guide shroud 70 and the motor cover 80 and surround the impeller. For airflow entering the heat absorption channel 420 from the first through-hole 701 from top to bottom, taking the clockwise rotation of the cooling fan 50 impeller as an example, after the impeller rotates, the airflow is forcefully thrown out in a clockwise direction. Due to the interaction between the heat absorption channel 420 and the contraction channel 430... The projection on the motor cover 80 is a rectangular area. The airflow velocity and flow rate are high in the first and fourth quadrants, and the flow direction is relatively stable. The heat-generating control device 60 is concentrated in this area, which can not only dissipate heat from the control device 60, but also has less impact from the airflow and can ensure that the airflow obtains sufficient temperature for heating. The static pressure is lowest and the flow velocity is slowest in the space enclosed by the guide shroud 70 and the motor cover 80. It is easy to generate flow separation and eddies. By setting the guide ribs 810, the airflow in the second and fourth quadrants is guided to the third quadrant area, so that the airflow is evenly ejected from the contraction channel 430.

[0077] like Figure 4 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the number of guide ribs 810 is not less than two, two adjacent guide ribs 810 are distributed at intervals in the third quadrant, and the distance between the guide ribs 810 and the rotation axis of the cold air fan 50 gradually decreases along the rotation direction of the fan blades of the cold air fan 50.

[0078] The number of guide ribs 810 can be no less than two; for example, the number of guide ribs 810 is three, the three guide ribs 810 are distributed at intervals in the third quadrant, and the distances between the three guide ribs 810 and the rotation axis of the air cooler 50 are D1, D2 and D3 respectively, and D1>D2>D3.

[0079] like Figure 1 and Figure 6 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the first air inlet 103 is distributed on the side wall of the housing 10 near the control device 60.

[0080] like Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further includes a reflector 90, which is disposed inside the housing 10, sandwiched between the cooking cavity 101 and the mounting cavity 102, and the hot air assembly 30 is located below the reflector 90.

[0081] The reflector 90 can reflect the radiant heat generated by the hot air assembly 30 back into the fryer 20 and prevent the heat from the cooking cavity 101 from entering the mounting cavity 102; the reflector 90 can be a flat plate or a metal plate with a specific curved surface.

[0082] It should be noted that in some examples, the reflector 90 and the motor cover 80 are integrally formed.

[0083] like Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further defines that: the housing 10 includes an outer shell 11 and an inner liner 12 disposed inside the outer shell 11. The inner liner 12 and the reflector 90 or the motor cover 80 enclose a cooking cavity 101. The outer wall of the inner liner 12 and the inner wall of the outer shell 11 form an air guide cavity 104. The air guide cavity 104 is connected to the shrinkage channel 430.

[0084] The outer shell 11 serves as the outermost shell structure of the air fryer 20; the inner liner 12 is disposed in the space formed inside the outer shell 11, forming the side wall and bottom wall of the cooking cavity 101, and the surface of the air fryer 20 is in close contact with or adjacent to the inner surface of the inner liner 12; the inner liner 12 may define the cooking cavity 101 together with either the reflector 90 or the motor cover 80.

[0085] The air guide cavity 104 is formed by the gap between the outer wall of the inner liner 12 and the inner wall of the outer shell 11, and is an open cavity surrounding the cooking cavity 101. Based on the high-speed airflow ejected from the constricted flow, part of it is directly sprayed onto the surface of the fryer 20 exposed in the cooking cavity 101, and the other part is guided into the air guide cavity 104. Since the surface of the fryer 20 exposed in the cooking cavity 101 lacks the heat dissipation buffer of the inner liner 12, and this area is where users are likely to accidentally touch it, cooling can be effectively achieved by directly spraying the accelerated airflow onto this area. Since the sides and bottom of the fryer 20 conduct heat through contact with the inner liner 12, another part of the airflow is introduced into the air guide cavity 104 between the inner liner 12 and the outer shell 11. The airflow introduced into the air guide cavity 104 cools the outer wall of the inner liner 12 and carries away the heat conducted from the fryer 20 to the inner liner 12, thereby forming a heat insulation layer between the inner liner 12 and the outer shell 11, blocking the heat transfer to the outer shell 11, and ensuring that the surface temperature of the outer shell 11 is always within a safe range.

[0086] In one example, the housing 11 includes a top cover and a body, with the top cover movably covering the body, and the top cover and the flow guide 70 enclosing each other to form an expansion channel 410.

[0087] like Figure 1 and Figure 3 As shown, in addition to the features of the above embodiments, this embodiment further specifies that: the cold air fan 50 includes a drive motor 51 and a first fan blade 52 located in the heat absorption channel 420, and the hot air assembly 30 includes a heating element 31 and a second fan blade 32 located in the cooking cavity 101.

[0088] One end of the rotating shaft of the drive motor 51 is connected to the first fan blade 52, and the other end is connected to the second fan blade 32.

[0089] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0090] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An air fryer (20) comprising a housing (10), a fryer (20) and a hot air assembly (30), the housing (10) having a cooking cavity (101) and a mounting cavity (102) above the cooking cavity (101), the fryer (20) being movably arranged in the cooking cavity (101), and the hot air assembly (30) being configured to provide hot air into the fryer (20), characterized in that, further comprising a cooling air duct, a cooling fan (50) and a control device (60) arranged in the cooling air duct, the cooling fan (50) being configured to suck external air into the cooling air duct and discharge the external air, and the control device (60) being configured to drive the cooling fan (50) and the hot air assembly (30) to work; the cooling air duct comprises an expansion flow channel (410), a heat absorption flow channel (420) and a contraction flow channel (430) connected in sequence along the air flow direction, the external air has a reduced flow rate in the expansion flow channel (410), the airflow after the speed reduction is heat exchanged in the heat absorption flow channel (420), the heated airflow has an increased flow rate in the contraction flow channel (430), and the airflow after the speed increase is at least partially guided to the outer surface of the fryer (20). The inner wall of the housing (10) and a flow guide cover (70) located in the mounting cavity (102) form the expansion flow channel (410); a first air inlet (103) is formed in the housing (10) and communicates with the expansion flow channel (410), the number of the first air inlets (103) is not less than one, a first through hole (701) is formed in the flow guide cover (70), the first air inlets (103), the expansion flow channel (410) and the first through hole (701) communicate in sequence, and the total flow area of the first air inlets (103) is less than the flow area of the first through hole (701). The flow guide cover (70) is connected with a motor cover (80) located in the mounting cavity (102), and the flow guide cover (70) covers the motor cover (80), the space enclosed by the flow guide cover (70) and the motor cover (80) forms the heat absorption flow channel (420) and the contraction flow channel (430), and the flow cross-sectional area of the contraction flow channel (430) gradually decreases along the air flow direction.

2. The air fryer (20) according to claim 1, characterized in that The cross section of the contraction flow channel (430) is arc-shaped.

3. The air fryer (20) of claim 2, characterized in that, The contraction flow channel (430) is arranged downstream of the heat absorption flow channel (420), and the heat absorption flow channel (420) and the contraction flow channel (430) are distributed circumferentially around the central axis of the first through hole (701).

4. The air popcorn maker (20) according to claim 3, characterized in that 6. The air fryer (20) according to claim 5, characterized in that, the projection of the heat absorption flow channel (420) and the contraction flow channel (430) on the motor cover (80) is a rectangular area.

5. The air popcorn maker (20) according to claim 3, characterized in that ​ ​ ​ The motor cover (80) is divided into a first quadrant, a second quadrant, a third quadrant and a fourth quadrant along a circumferential direction with the central axis of the first through hole (701) as a center, the control device (60) is distributed in the first quadrant and / or the fourth quadrant, and the motor cover (80) is provided with a flow guide rib (810) at the third quadrant.

7. The air fryer (20) according to claim 6, characterized in that The number of the flow guide ribs (810) is not less than two, adjacent two flow guide ribs (810) are distributed in the third quadrant, and the distance between the flow guide rib (810) and the rotating shaft of the cold air fan (50) gradually decreases in the rotating direction of the fan blade of the cold air fan (50). And / or, The first air inlet (103) is distributed at one end of the side wall of the shell (10) close to the control device (60).

8. The air popcorn maker (20) according to claim 3, characterized in that Further comprising a reflecting cover (90) arranged in the shell (10), the reflecting cover (90) is clamped between the cooking cavity (101) and the mounting cavity (102), and the hot air assembly (30) is located below the reflecting cover (90).

9. The air popcorn maker (20) according to claim 8, characterized in that The shell (10) comprises an outer shell (11) and an inner liner (12) arranged in the outer shell (11), the inner liner (12) and the reflecting cover (90) or the motor cover (80) form the cooking cavity (101), the outer wall of the inner liner (12) and the inner wall of the outer shell (11) form an air guide cavity (104), and the air guide cavity (104) is in communication with the converging flow channel (430).

10. The air fryer (20) of claim 1, characterized in that, The cold air fan (50) comprises a driving motor (51) and a first fan blade (52) located in the heat absorption flow channel (420), the hot air assembly (30) comprises a heating element (31) and a second fan blade (32) located in the cooking cavity (101), one end of the rotating shaft of the driving motor (51) is in transmission connection with the first fan blade (52), and the other end is in transmission connection with the second fan blade (32).

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