A range hood and its working method

Abstract

This invention relates to a range hood, comprising a fan housed within a casing, including a volute and an impeller with multiple blades; a water outlet mechanism positioned above the impeller for discharging water onto the blades; a detection module positioned below the blades for detecting water droplets falling onto them; and a control circuit board electrically connected to the water outlet mechanism and the detection module. This range hood can accurately determine the presence and degree of oil contamination on the impeller and can perform self-cleaning. The invention also relates to a method for operating the range hood, comprising the following steps: initializing a standard time interval [T1, T2] for the blades to be in a clean state; activating the fan's contamination detection function; controlling the dispensing of water droplets onto the blades and recording the water droplet dispensing time Ts; recording the water droplet falling time Tz; calculating the time T = Tz - Ts for the water droplets to fall from the water outlet mechanism and slide down the blades onto the detection module; if T > T2, then the blades are determined to be in an oil-contaminated state; otherwise, the blades are determined to be in a clean state.

Description

Technical Field

[0001] This invention relates to a range hood, and also to a method of operating the range hood. Background Technology

[0002] Range hoods have become an indispensable household appliance in countless homes. While bringing convenience, they also present significant cleaning challenges. Range hoods use a fan system to expel cooking fumes outdoors or through shared ventilation ducts, meaning the fumes inevitably pass through this system. This system typically includes an impeller and a volute. As the fumes pass through, grease accumulates on the impeller and volute. If not cleaned regularly, this buildup forms grime, clogging the air intake channels between the blades, reducing performance, and affecting smoke extraction and cooking. Furthermore, long-term grease buildup can negatively impact the kitchen's air quality, posing a health risk to users. Currently, most range hoods lack grease detection capabilities, and deep cleaning requires disassembling the impeller for manual cleaning, which is time-consuming, labor-intensive, and often impractical for home users. Professional cleaning is also a significant expense.

[0003] Some range hoods use grease detection technology that reminds users to clean or initiate self-cleaning based on the recorded operating time. For example, the Chinese invention patent CN110822511B (application number 201910993706.5), entitled "A Motor Control Method for Automatic Cleaning Process of a Range Hood," discloses a range hood that times the cumulative motor operation. When the cumulative operating time exceeds a threshold, it initiates self-cleaning. However, cooking methods vary across regions. Within the same cumulative operating time, different cooking methods often produce different amounts of grease, resulting in varying levels of grease residue on the impeller and volute. Therefore, using cumulative operating time to determine the amount of grease accumulation often leads to significant errors. Summary of the Invention

[0004] The first technical problem to be solved by the present invention is to provide a range hood that can accurately determine whether there is oil on the impeller and the degree of oil contamination, and can achieve self-cleaning, in contrast to the above-mentioned prior art.

[0005] The second technical problem to be solved by the present invention is to provide a method for operating a range hood that can determine whether the impeller is contaminated with oil, in contrast to the above-mentioned prior art.

[0006] The third technical problem to be solved by the present invention is to provide a working method for a range hood that can accurately determine the degree of oil contamination on the impeller, in contrast to the above-mentioned prior art.

[0007] The fourth technical problem to be solved by the present invention is to provide a working method for a self-cleaning range hood that is in contrast to the above-mentioned prior art.

[0008] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a range hood, comprising...

[0009] A fan, housed within a casing, comprising a volute and an impeller with multiple blades;

[0010] Its features include:

[0011] The water outlet mechanism is located above the impeller and can discharge water onto the blades;

[0012] The detection module, located below the blade, is used to detect the signal of water droplets falling on it;

[0013] The control circuit board is electrically connected to the water outlet mechanism and the detection module.

[0014] In order to effectively adjust the water outlet state when the water outlet mechanism is performing oil stain detection and when it is performing self-cleaning, the water outlet of the water outlet mechanism is equipped with a flow regulating valve, which is connected to the control circuit board by electrical signal.

[0015] To minimize the impact on the range hood during normal smoke extraction and to prevent smoke from contaminating the water outlet mechanism, the water outlet mechanism is installed on the housing and located above the volute. The volute has an opening corresponding to the water outlet mechanism, through which water is discharged to the blades.

[0016] In order to ensure that the water from the water outlet mechanism acts on the blades as much as possible and avoids splashing, the water outlet mechanism is movable up and down on the housing to enter and exit the opening.

[0017] Preferably, the housing is provided with a first drive mechanism that drives the water outlet mechanism to move up and down, and the first drive mechanism is electrically connected to the control circuit board.

[0018] As an improvement, the opening of the volute is provided with an openable cover plate, and the volute is provided with a driver to drive the cover plate to open and close. The driver is electrically connected to the control circuit board.

[0019] Preferably, a water box is provided on the housing, and the water outlet mechanism is connected to the water box.

[0020] To improve the cleaning effect during the self-cleaning process of the water outlet mechanism, a heating device is provided inside the water box, and the heating device is electrically connected to the control circuit board.

[0021] Preferably, the water outlet mechanism includes a base having a cavity and a plurality of water outlets connected to the base. The water outlets are arranged below the base along the length direction of the blades and are connected to the cavity.

[0022] To facilitate adjustment of the water outlet direction in both dripping and self-cleaning modes, the water outlet end of the nozzle is equipped with a rotatable electric nozzle, which is electrically connected to the control circuit board.

[0023] Preferably, the detection module includes a support plate disposed below the blade and a first detector disposed on the support plate, the first detector being electrically connected to the control circuit board.

[0024] To facilitate the installation of the support plate and minimize its impact on the impeller's normal operation, the detection module also includes a base and a second drive mechanism. The base is fixed to the side of the volute, the support plate is rotatably connected to the base, and the second drive mechanism is driven by the support plate to rotate relative to the base. The second drive mechanism is electrically connected to the control circuit board.

[0025] Alternatively, the first detector may be a camera and / or a water droplet sensor disposed along the extension direction of the support plate.

[0026] To more accurately determine the timing of water droplet dispensing, a second detector is provided on the water dispensing mechanism near the water dispensing position for detecting the timing of water dispensing.

[0027] Preferably, the second detector is a camera.

[0028] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a working method of a range hood, characterized in that: a range hood as described above is used;

[0029] The working method of a range hood includes the following steps;

[0030] S1. Initialize the blades to a clean state. The water outlet mechanism drips water droplets that slide off the blades and fall onto the detection module within the standard time interval [T1,T2].

[0031] S2. Start the fan pollution detection work;

[0032] S3. Control the water outlet mechanism to drip water droplets onto the blades and record the water droplet dripping time Ts;

[0033] S4. After the detection module detects the water droplet signal, it records the water droplet's falling time Tz.

[0034] Then, the time it takes for the water droplet to drip from the water outlet mechanism and slide down the blade onto the detection module is calculated as T = Tz - Ts;

[0035] S5. Compare T with T1 and T2;

[0036] If T > T2, the blade is determined to be in an oily state; otherwise, the blade is determined to be in a clean state.

[0037] The technical solution adopted by the present invention to solve the third technical problem mentioned above is as follows: when it is determined that the blade is in an oily state, the degree of oil contamination of the blade is determined based on the multiple of T relative to T2.

[0038] The technical solution adopted by the present invention to solve the third technical problem mentioned above is as follows: In S1, under different degrees of leaf contamination, the water droplets dripping from the water outlet mechanism slide off the leaf and fall to different areas on the detection module.

[0039] In S4, after the detection module detects the water droplet signal, it simultaneously records the droplet's landing position on the detection module.

[0040] In S5, when it is determined that the blade is in an oily state, the degree of oiliness of the blade is determined based on the area range where the water droplets fall on the detection module.

[0041] The technical solution adopted by the present invention to solve the fourth technical problem mentioned above is as follows: when the degree of oil contamination on the blades exceeds the set oil contamination threshold, the water outlet mechanism is controlled to perform self-cleaning on the impeller and the volute.

[0042] As an improvement, the self-cleaning parameters of the water outlet mechanism are matched according to the degree of oil contamination on the blades.

[0043] To ensure the self-cleaning effect, after the water outlet mechanism performs self-cleaning on the impeller and volute, the degree of oil contamination on the blades is re-tested and judged.

[0044] This process continues until the blades are determined to be clean or the self-cleaning count reaches the set threshold.

[0045] The technical solution adopted by the present invention to solve the second technical problem mentioned above is: a working method of a range hood, characterized in that: a range hood as described above is used;

[0046] The working method of a range hood includes the following steps;

[0047] Step 1: Initialize the blades to a clean state. Water droplets from the water outlet mechanism slide off the blades and land on the detection module at a distance [X1, X2] relative to the set origin line in the width direction of the detection module.

[0048] Step 2: Initiate the fan pollution detection process;

[0049] Step 3: Control the water outlet mechanism to drip water droplets onto the blades;

[0050] Step 4: After the detection module detects the water droplet signal, it records the position where the water droplet falls.

[0051] Calculate the distance X of the water droplet's landing position relative to the set origin line in the width direction of the detection module;

[0052] Step 5: Compare X with X1 and X2;

[0053] If X > X2, the blade is determined to be in an oily state; otherwise, the blade is determined to be in a clean state.

[0054] The technical solution adopted by the present invention to solve the third technical problem mentioned above is as follows: when it is determined that the blade is in an oily state, the degree of oil contamination of the blade is determined based on the multiple of X relative to X2.

[0055] The technical solution adopted by the present invention to solve the fourth technical problem mentioned above is as follows: when the degree of oil contamination on the blades exceeds the set oil contamination threshold, the water outlet mechanism is controlled to perform self-cleaning on the impeller and the volute.

[0056] As an improvement, the self-cleaning parameters of the water outlet mechanism are matched according to the degree of oil contamination on the blades.

[0057] To ensure the self-cleaning effect, after the water outlet mechanism performs self-cleaning on the impeller and volute, the degree of oil contamination on the blades is re-tested and judged.

[0058] This process continues until the blades are determined to be clean or the self-cleaning count reaches the set threshold.

[0059] Compared with existing technologies, the advantages of this invention are as follows: The range hood of this invention is equipped with a water outlet mechanism that discharges water to the blades, and also includes a detection module for detecting water droplet signals. Through the cooperation of the water outlet mechanism and the detection module, based on the different flow speeds of water on blades with and without oil, the detection module detects different parameter information. Therefore, based on the differences in the detected information, it is possible to determine whether there is oil on the blades and the degree of oil contamination. This allows for a more accurate assessment of the oil contamination on the blades, solving the problem in existing technologies that cannot effectively distinguish the differences in oil accumulation on the impeller caused by different cooking habits. This also facilitates the cleaning of the fan, such as determining a more accurate cleaning time and adjusting cleaning parameters according to the degree of oil contamination. Furthermore, while detecting oil contamination, the water outlet mechanism can also perform self-cleaning of the fan by increasing the water flow rate, making it multi-functional and highly intelligent.

[0060] The range hood of this invention is based on the principle that water droplets experience different frictional forces when rolling on different media, resulting in differences in dripping time and location. By observing the differences in water droplet drop patterns, the invention can determine whether the fan is contaminated and the degree of contamination. This allows for accurate assessment of the fan's contamination level, facilitating the matching of more suitable cleaning parameters and solving the problem of mismatch between cleaning parameters and fan contamination levels caused by different user cooking habits. Attached Figure Description

[0061] Figure 1 This is a diagram showing the internal structure of the range hood in an embodiment of the present invention.

[0062] Figure 2 This is a cross-sectional view of the range hood in an embodiment of the present invention.

[0063] Figure 3 This is a diagram showing the state of water dripping in cooperation with the blades in an embodiment of the present invention.

[0064] Figure 4 These are two state diagrams showing the water outlet mechanism and blades working together to perform self-cleaning in an embodiment of the present invention. Detailed Implementation

[0065] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0066] like Figures 1 to 4 As shown, the range hood in this embodiment includes a housing 2, a fan 1, a water outlet mechanism 3, a detection module 4, and a control circuit board.

[0067] The fan 1 is housed within the casing 2. The fan 1 includes a volute 11 and an impeller 12 with multiple blades 121. The fan 1 can employ various existing fan 1 structures found in range hoods. Typically, to ensure the installation stability of the motor driving the impeller 12 and to facilitate the drive connection between the motor and the impeller 12, a central disc structure is radially arranged in the middle of the impeller 12, and the motor's drive shaft is connected to this central disc. The multiple blades 121 on the impeller 12 are circumferentially distributed and extend axially.

[0068] The water outlet mechanism 3 is located above the impeller 12 and can discharge water onto the blades 121. In this embodiment, the water outlet mechanism 3 includes a base 31 with a cavity and a plurality of water outlet nozzles 32 connected to the base 31. The water outlet nozzles 32 are arranged below the base 31 along the length direction of the blades 121 and are connected to the cavity.

[0069] The water outlet of the water outlet mechanism 3 is equipped with a flow regulating valve, which is electrically connected to the control circuit board. The flow regulating valve can adjust the water outlet opening of the water outlet mechanism 3 based on the control signal from the control circuit board, allowing the water outlet mechanism 3 to discharge water at a small flow rate to form water droplets. The presence and degree of oil contamination on the blades are determined based on the time and / or position of the water droplets falling on the detection module 4, thus enabling the operation of the range hood as described below, and thereby detecting the oil contamination on the impeller 12. The flow regulating valve can also allow the water outlet mechanism 3 to discharge water at a large flow rate, thereby acting on the blades 121 to achieve self-cleaning of the blades 121.

[0070] The water outlet mechanism 3 can be directly connected to a water source. For ease of use, a water box 6 can also be installed on the housing 2, and the water outlet mechanism 3 is connected to the water box 6. During use, water can be filled into the water box 6 to supply the water outlet mechanism 3 for a longer period. To improve the cleaning effect on the volute 11 and impeller 12 during the self-cleaning function of the water outlet mechanism 3, a heating device is installed in the water box 6. The heating device is electrically connected to the control circuit board. During self-cleaning, the control circuit board controls the flow regulating valve and simultaneously controls the heating temperature of the water in the water box, so as to perform self-cleaning with water at a suitable flow rate and temperature, thereby improving the self-cleaning effect.

[0071] In addition, in this embodiment, the water outlet mechanism 3 is specifically disposed on the housing 2 and located above the volute 11. The volute 11 has an opening 111 corresponding to the water outlet mechanism 3, through which water is discharged from the water outlet mechanism 3 onto the blades 121. The placement of the water outlet mechanism 3 avoids affecting the operation of the impeller 12 when the range hood is normally extracting fumes, and also avoids the contamination of the water outlet mechanism 3 by fumes. However, the placement of the water outlet mechanism 3 is relatively far from the blades 121 on the impeller 12, and due to the limited area of ​​the opening 111, water is prone to being deflected and splashed when discharging onto the blades 121. In order to ensure that the water discharged from the water outlet mechanism 3 acts on the blades 121 as much as possible, the water outlet mechanism 3 is movably disposed on the housing 2 and enters and exits the opening 111. Specifically, the housing 2 is provided with a first drive mechanism 5 for driving the water outlet mechanism 3 to move up and down. The first drive mechanism 5 is electrically connected to the control circuit board, and thus the first drive mechanism 5 drives the water outlet mechanism 3 to move up or down under the control of the control circuit board. Typically, when the range hood needs to be inspected for grease or when it needs to self-clean, the first drive mechanism 5 drives the water outlet mechanism 3 downwards, bringing it closer to the upper part of the impeller 12. When the range hood is not in use or is performing normal fume extraction, the first drive mechanism 5 drives the water outlet mechanism 3 upwards, moving it away from the interior of the volute 11 and onto the outside of the volute 11. The first drive mechanism 5 can employ various existing drive mechanisms, such as a combination of a motor and a transmission mechanism, or an electric telescopic rod.

[0072] Since the volute 11 has an opening 111, smoke can easily escape through this opening when the range hood is operating normally. To solve this problem, this embodiment includes an openable cover plate on the opening 111 of the volute 11. The volute 11 is equipped with a driver that drives the cover plate to open and close. The driver is electrically connected to the control circuit board. This driver can employ various existing driving mechanisms, such as an electric push rod. When the first driving mechanism 5 drives the water outlet mechanism 3 to move upwards outside the volute 11, the driver is controlled to drive the cover plate to close the opening 111. When the first driving mechanism 5 needs to drive the water outlet mechanism 3 into the volute 11 and near the impeller 12, the driver is controlled to drive the cover plate to open the opening 111.

[0073] To facilitate adjustment of the water outlet direction in both dripping and self-cleaning modes, the water outlet 32 ​​is equipped with a rotatable electric nozzle 33 at its outlet end. The electric nozzle 33 is electrically connected to the control circuit board. The blades 121 on the impeller 12 typically have a certain curvature. When oil stain detection is required, the nozzle 33 is adjusted to a vertical position, facilitating the dripping of water droplets onto the outer surface of the blades 121. When self-cleaning is required, the electric nozzle can be controlled to rotate, thus facilitating the cleaning of the outer and inner surfaces of the blades 121, as well as various parts of the volute 11.

[0074] The detection module 4 is located below the blade 121 and is used to detect water droplets falling on it. Based on the detection of water droplet signals by the detection module 4, the following operating method of the range hood can determine whether the blade 121 is in an oily state and the degree of oiliness on the blade 121. The control module is electrically connected to the control circuit board and can transmit the detection signal to the control circuit board. The control circuit board can then perform calculations and judgments based on the detection signal from the detection module 4.

[0075] The detection module 4 includes a support plate 41 disposed below the blade 121 and a first detector 42 disposed on the support plate 41. The first detector 42 is electrically connected to the control circuit board. In this embodiment, the support plate 41 extends along the extension direction of the blade 121, and the width of the support plate 41 is slightly wider than the width of the blade 121. During detection, the water outlet mechanism 3 dispenses water droplets, which fall onto the first detector 42 on the support plate 41 after passing through the blade 121. Based on the water droplet signal detected by the first detector 42, corresponding calculation parameters are obtained to achieve oil stain detection.

[0076] For the impeller 12 with a central plate, a detection module 4 can be installed below the blades 121 on both sides of the central plate.

[0077] To facilitate the installation of the support plate 41 and minimize its impact on the normal operation of the impeller 12, the detection module 4 also includes a base 43 and a second drive mechanism. The base 43 is fixed to the side of the volute 11, and the support plate 41 is rotatably connected to the base 43. The second drive mechanism is driven by the support plate and drives the support plate 41 to rotate relative to the base 43. The second drive mechanism is electrically connected to the control circuit board. The second drive mechanism can adopt various drive structures in the prior art. When oil contamination detection of the impeller 12 is required, the control circuit board controls the second drive mechanism to drive the support plate 41 to rotate to a horizontal position, thus placing it below the blade 121. When oil contamination detection of the impeller 12 is not required, the control circuit board controls the second drive mechanism to drive the support plate 41 to rotate to a vertical position, thus placing it outside the impeller 12 and not affecting the rotation of the impeller 12.

[0078] In this embodiment, the first detector 42 is a camera and / or a water droplet sensor arranged along the extension direction of the support plate 41.

[0079] When using a camera, it can be positioned along the edge of the support plate 41 to easily capture the timing and position information of water droplets falling onto the support plate 41. Especially when using the timing to determine oil stains, the camera, acting as the first detector 42, can also detect the timing of water droplet emergence. However, to avoid obstruction of the camera's detection of water discharge from the water outlet mechanism 3 by other components, and to more accurately determine the timing of water droplet emergence, a second detector, also using a camera, can be installed on the water outlet mechanism 3 near the water outlet position. Thus, based on the first detector 42 and the second detector, the timing of water droplet emergence and the timing of water droplet falling onto the support plate 41 can be accurately obtained.

[0080] When using a water droplet sensor, such as a capacitive or pressure-type sensor from existing technologies, the sensor is laid flat on the support plate 41. When water droplets fall, they land directly on the sensor, which determines the droplet's position based on a signal change at that location. This facilitates position-based oil stain detection using the methods described below.

[0081] The working principle of the range hood in this embodiment is as follows: the friction between water droplets and blades 121 with different viscosity is different, and the sliding speed of the water droplets on the blades 121 is different. Based on this, the time it takes for the water droplets to slide off the blades 121 is different, and the position where they fall after sliding off is also different. Based on these differences, it is possible to determine whether there is oil on the blades 121 and the degree of oil on the blades 121.

[0082] The impeller 12 has an upwardly curved cross-section. When the blade 121 is positioned in a gradually downward curved position, the water droplet is controlled to land at the upper end of the blade 121. The water droplet then slides down the blade 121. The more oil and dirt on the blade 121, the higher the viscosity of the blade 121 surface, resulting in greater resistance to the sliding of the water droplet and a slower sliding speed. Thus, the water droplet waits longer to fall onto the support plate 41. Simultaneously, due to the reduced sliding speed, the water droplet's impact force is smaller, causing it to fall from a lower position on the blade 121 onto the support plate 41. Consequently, the distance from the bottom of the blade 121 to the water droplet's landing position on the support plate 41 is shorter in the horizontal direction. Conversely, the shorter the waiting time for the water droplet to fall onto the support plate 41, the longer the distance from the bottom of the blade 121 to the water droplet's landing position on the support plate 41 is in the horizontal direction.

[0083] Based on this, the working method of the range hood in this embodiment includes the following steps;

[0084] S1. Initialize the blades 121 to a clean state. The water outlet mechanism 3 drips water droplets, which slide off the blades 121 and fall onto the detection module 4 over a standard time interval [T1, T2]. This standard time interval can be obtained during product testing or during the first use of the range hood. During acquisition, the impeller 12 is controlled to rotate to a specific position so that one side of one blade 121 is in a basically horizontal state and is just below the nozzle 33 in the water outlet mechanism 3.

[0085] S2. Start the pollution detection function of fan 1. This function can be automatically activated based on the operating time of the range hood, such as after each use, before each use, or at regular intervals. Alternatively, this function can be activated by the user. For example, a cleaning status detection function key can be set on the range hood and connected to the control circuit board. When the user presses this key, the control circuit board, upon receiving the signal, will activate the pollution detection function of fan 1.

[0086] S3. Control the impeller 12 to rotate to a specific position that is the same as the standard time interval obtained, so that one blade 121 can be positioned below the nozzle 33 in the water outlet mechanism 3 in the same posture as in S1. Control the first drive mechanism 5 to drive the water outlet mechanism 3 to move down through the opening 111 on the volute 11 to above the impeller 12, so that the position of the water outlet mechanism 3 relative to the blade 121 of the detection module 4 is the same as when the standard time interval was obtained.

[0087] The control circuit board adjusts the opening of the flow regulating valve, causing the nozzle 33 of the water outlet mechanism 3 to drip a drop of water onto the blade 121, and records the water droplet dripping time Ts. Depending on the needs, this water droplet dripping time Ts can be based on the start time of the control water outlet mechanism 3, or it can be obtained from the aforementioned second detector to determine the moment the water droplet leaves the nozzle 33.

[0088] S4. After a water droplet lands on the detection module 4, the detection module 4 detects the water droplet signal and controls the circuit board to record the droplet's falling time Tz. Then, the control circuit board calculates the time it takes for the water droplet to fall from the water outlet mechanism 3 and slide down the blade 121 onto the detection module 4, T = Tz - Ts.

[0089] S5. Compare T with T1 and T2. If T > T2, then blade 121 is determined to be in an oily state; otherwise, blade 121 is determined to be in a clean state.

[0090] When the blade 121 is determined to be oily, the degree of oil contamination is determined based on the ratio of T to T2. That is, the larger the ratio of T to T2, the higher the degree of oil contamination on the blade 121. When the degree of oil contamination on the blade 121 exceeds the set threshold, the control mechanism adjusts the opening of the water flow regulating valve so that the water output from the water outlet mechanism 3 is the amount of water required for self-cleaning. The water outlet mechanism 3 then performs self-cleaning on the impeller 12 and the volute 11. Furthermore, the control circuit board matches the corresponding self-cleaning parameters of the water outlet mechanism 3 according to the degree of oil contamination on the blade 121. These self-cleaning parameters can include cleaning duration, cleaning water volume, and / or cleaning temperature.

[0091] To ensure the self-cleaning effect, after the water outlet mechanism 3 performs self-cleaning on the impeller 12 and the volute 11, the degree of oil contamination on the blade 121 is re-detected and judged using the aforementioned method. This process is repeated until the blade 121 is judged to be in a clean state or the number of self-cleaning times reaches the set threshold.

[0092] The range hood of this invention is equipped with a water outlet mechanism 3 that discharges water to the blades 121, and a detection module 4 that detects water droplet signals. Through the cooperation of the water outlet mechanism 3 and the detection module 4, the different flow speeds of water on the oil-free and oil-stained blades 121 result in different parameter information detected by the detection module 4. Based on these differences, the presence and degree of oil stains on the blades 121 can be determined, thus more accurately assessing the oil stain condition on the blades 121. This solves the problem in existing technologies where it is difficult to effectively distinguish the differences in oil stain accumulation on the impeller 121 caused by different cooking habits. This also facilitates cleaning of the fan 1, such as determining a more accurate cleaning time and adjusting cleaning parameters according to the degree of oil stains. Furthermore, while detecting oil stains, the water outlet mechanism 3 can also perform self-cleaning of the fan 1 by increasing the water flow rate, making it a multi-functional and highly intelligent system.

[0093] The range hood of this invention is based on the principle that water droplets experience different frictional forces when rolling on different media, resulting in differences in dripping time and location. By observing the differences in water droplet droplet drop patterns, the invention can determine whether the fan 1 is contaminated and the degree of contamination. This allows for accurate assessment of the contamination status of the fan 1, facilitating the matching of more suitable cleaning parameters and solving the problem of mismatch between cleaning parameters and the contamination status of the fan 1 due to different user cooking habits.

[0094] The specification and claims of this invention use terms indicating direction, such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom," to describe various exemplary structural parts and elements of the invention. However, these terms are used herein merely for ease of explanation and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these terms indicating direction are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity.

[0095] Example 2

[0096] The difference between this embodiment and Embodiment 1 is that the method for determining the degree of oil contamination on blade 121 is different.

[0097] Specifically, in S1, water droplets from the water outlet mechanism 3 are initialized simultaneously under different contamination levels of the blades 121, and slide down the blades 121 to different areas on the detection module 4. Typically, based on the different contamination levels on the blades 121, the water droplets will fall in different areas along the width of the support plate 41. Thus, areas corresponding to different contamination levels of the blades 121 can be divided along the width of the support plate 41.

[0098] Accordingly, in S4, after the detection module 4 detects the water droplet signal, it simultaneously records the droplet position on the detection module 4.

[0099] In S5, when it is determined that the blade 121 is in an oily state, the degree of oiliness of the blade 121 is determined based on the area range where the water droplets fall on the detection module 4.

[0100] Example 3

[0101] The difference between this embodiment and Embodiment 1 is that the working method of the range hood is different.

[0102] Specifically, the working method of the range hood in this embodiment includes the following steps;

[0103] Step 1: Initialize the blade 121 to a clean state. The water outlet mechanism 3 drops water through the blade 121 and slides onto the detection module 4. The drop position is within the distance range [X1, X2] of the detection module 4 relative to the set origin line in the width direction of the detection module 4.

[0104] Step 2: Start the pollution detection work for fan 1;

[0105] Step 3: Control the water outlet mechanism 3 to drip water droplets onto the blade 121;

[0106] Step 4: After the detection module 4 detects the water droplet signal, it records the position where the water droplet falls.

[0107] Calculate the distance X of the water droplet's landing position relative to the set origin line in the width direction of the detection module 4;

[0108] Step 5: Compare X with X1 and X2;

[0109] If X > X2, then blade 121 is determined to be in an oily state; otherwise, blade 121 is determined to be in a clean state.

[0110] The technical solution adopted by the present invention to solve the third technical problem mentioned above is as follows: when it is determined that the blade 121 is in an oily state, the degree of oil contamination of the blade 121 is determined based on the multiple of X relative to X2.

Claims

1. A range hood, comprising: A fan (1) is installed inside a casing (2) and includes a volute (11) and an impeller (12) with multiple blades (121). Its features are: Also includes The water outlet mechanism (3) is located above the impeller (12) and can discharge water onto the blades (121); The detection module (4) is located below the blade (121) and is used to detect the water droplet signal falling on it, the water droplet signal including the water droplet time and / or the water droplet position; The control circuit board is electrically connected to the water outlet mechanism (3) and the detection module (4). The control circuit board controls and adjusts the water outlet opening of the water outlet mechanism (3) so that the water outlet mechanism (3) can produce water droplets with a small flow rate. The control circuit board judges the oil stain status of the blade (121) based on the time and / or position of the water droplets falling on the detection module (4).

2. The range hood according to claim 1, characterized in that: The outlet of the water outlet mechanism (3) is equipped with a flow regulating valve, which is electrically connected to the control circuit board.

3. The range hood according to claim 1, characterized in that: The water outlet mechanism (3) is installed on the housing (2) and located above the volute (11). The volute (11) has an opening (111) corresponding to the water outlet mechanism (3). The water outlet mechanism (3) discharges water to the blade (121) through the opening (111).

4. The range hood according to claim 3, characterized in that: The water outlet mechanism (3) is movable up and down on the housing (2) and enters and exits the opening (111).

5. The range hood according to claim 4, characterized in that: The housing (2) is provided with a first drive mechanism (5) that drives the water outlet mechanism (3) to move up and down. The first drive mechanism (5) is electrically connected to the control circuit board.

6. The range hood according to any one of claims 3 to 5, characterized in that: The volute (11) has an openable cover plate on its opening (111), and the volute (11) is provided with a driver to drive the cover plate to open and close. The driver is electrically connected to the control circuit board.

7. The range hood according to any one of claims 1 to 5, characterized in that: A water box (6) is provided on the housing (2), and the water outlet mechanism (3) is connected to the water box (6).

8. The range hood according to claim 7, characterized in that: The water box (6) is equipped with a heating device, which is electrically connected to the control circuit board.

9. The range hood according to any one of claims 1 to 5, characterized in that: The water outlet mechanism (3) includes a base (31) with a cavity and a plurality of water outlets (32) connected to the base (31). The water outlets (32) are arranged below the base (31) along the length direction of the blade (121) and are connected to the cavity.

10. The range hood according to claim 9, characterized in that: The water outlet (32) is provided with a rotatable electric nozzle (33) at the water outlet end, and the electric nozzle (33) is electrically connected to the control circuit board.

11. The range hood according to any one of claims 1 to 5, characterized in that: The detection module (4) includes a support plate (41) disposed below the blade (121) and a first detector (42) disposed on the support plate (41), the first detector (42) being electrically connected to the control circuit board.

12. The range hood according to claim 11, characterized in that: The detection module (4) also includes a base (43) and a second driving mechanism. The base (43) is fixed to the side of the volute (11). The support plate (41) is rotatably connected to the base (43). The second driving mechanism is driven to rotate relative to the base (43) by driving the support plate (41). The second driving mechanism is electrically connected to the control circuit board.

13. The range hood according to claim 11, characterized in that: The first detector (42) is a camera and / or a water droplet sensor arranged along the extension direction of the support plate (41).

14. The range hood according to claim 13, characterized in that: The water outlet mechanism (3) is equipped with a second detector near the water outlet position for detecting the timing of water outlet.

15. The range hood according to claim 14, characterized in that: The second detector is a camera.

16. A method for operating a range hood, characterized in that: The range hood described in any one of claims 1 to 15 is adopted; The working method of a range hood includes the following steps; S1. Initialize the blade (121) to be in a clean state, and the water outlet mechanism (3) drips water droplets and slides through the blade (121) to the standard time interval [T1,T2] on the detection module (4); S2. Start the fan (1) pollution detection work; S3. Control the water outlet mechanism (3) to drip water droplets onto the blade (121) and record the water droplet dripping time Ts; S4. After the detection module (4) detects the water droplet signal, it records the dripping time Tz of the water droplet. Then calculate the time T = Tz - Ts from the water droplet dripping from the water outlet mechanism (3) and sliding down the blade (121) onto the detection module (4); S5. Compare T with T1 and T2; If T > T2, then the blade (121) is in an oily state; otherwise, the blade (121) is in a clean state.

17. The working method according to claim 16, characterized in that: When it is determined that the blade (121) is in an oily state, the degree of oil contamination of the blade (121) is determined based on the multiple of T relative to T2.

18. The working method according to claim 16, characterized in that: In S1, water droplets from the water outlet mechanism (3) are initialized simultaneously under different degrees of contamination of the blades (121) and slide down the blades (121) to different areas on the detection module (4); In S4, after the detection module (4) detects the water droplet signal, it simultaneously records the droplet position on the detection module (4); In S5, when it is determined that the blade (121) is in an oily state, the degree of oiliness of the blade (121) is determined based on the area range of the water droplet's dripping position on the detection module (4).

19. The working method according to claim 17 or 18, characterized in that: When the oil stain level of the blade (121) exceeds the set oil stain level threshold, the water outlet mechanism (3) controls the impeller (12) and the volute (11) to perform self-cleaning.

20. The working method according to claim 19, characterized in that: The self-cleaning parameters of the corresponding water outlet mechanism (3) are matched according to the degree of oil contamination on the blades (121).

21. The working method according to claim 19, characterized in that: After the water outlet mechanism (3) performs self-cleaning on the impeller (12) and volute (11), the degree of oil contamination on the blades (121) is re-tested and judged. This process is repeated until it is determined that the blade (121) is in a clean state or the number of self-cleaning cycles reaches the set threshold.

22. A method for operating a range hood, characterized in that: The range hood described in any one of claims 1 to 15 is adopted; The working method of a range hood includes the following steps; Step 1: Initialize the blade (121) to be in a clean state. The water outlet mechanism (3) drips water droplets that slide off the blade (121) onto the detection module (4). The dripping position is within the distance range [X1,X2] of the detection module (4) relative to the set origin line in the width direction. Step 2: Start the fan (1) pollution detection work; Step 3: Control the water outlet mechanism (3) to drip water droplets onto the blade (121); Step 4: After the detection module (4) detects the water droplet signal, it records the position where the water droplet falls. Calculate the distance X of the water droplet's landing position relative to the set origin line in the width direction of the detection module (4); Step 5: Compare X with X1 and X2; If X > X2, then the blade (121) is in an oily state; otherwise, the blade (121) is in a clean state.

23. The working method according to claim 22, characterized in that: When it is determined that the blade (121) is in an oily state, the degree of oil contamination of the blade (121) is determined based on the multiple of X relative to X2.

24. The working method according to claim 23, characterized in that: When the oil stain level of the blade (121) exceeds the set oil stain level threshold, the water outlet mechanism (3) controls the impeller (12) and the volute (11) to perform self-cleaning.

25. The working method according to claim 24, characterized in that: The self-cleaning parameters of the corresponding water outlet mechanism (3) are matched according to the degree of oil contamination on the blades (121).

26. The working method according to claim 24, characterized in that: After the water outlet mechanism (3) performs self-cleaning on the impeller (12) and volute (11), the degree of oil contamination on the blades (121) is re-tested and judged. This process is repeated until it is determined that the blade (121) is in a clean state or the number of self-cleaning cycles reaches the set threshold.

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