Range hood and control method thereof

Abstract

The present invention discloses a range hood and a control method thereof, wherein the range hood comprises a movable part and a lifting and lowering mechanism for driving the movable part to lift and lower, wherein the lifting and lowering mechanism comprises a motor, and is characterized in that: the range hood further comprises a control module, which is electrically connected to the lifting and lowering mechanism, and can obtain the resistance change of the movable part by monitoring the current output speed of the motor, and adjust the current output speed or input power of the motor according to the resistance change. Compared with the prior art, the advantages of the present invention are: by regulating the power and output speed according to the load resistance, the uniformity of the descending speed can be ensured when the load increases, the stability and reliability of the lifting function can be improved, and the user experience can be improved.

Description

Technical Field

[0001] The invention relates to an oil fume purification device, in particular to a range hood and a control method of the range hood. Background Art

[0002] Range hoods have become one of the indispensable kitchen appliances in modern families. Range hoods work based on the principle of fluid dynamics. A centrifugal fan installed inside the range hood absorbs and exhausts oil smoke, and uses a filter to filter out some grease particles. The centrifugal fan includes a volute, an impeller installed in the volute, and a motor that drives the impeller to rotate. When the impeller rotates, negative pressure suction is generated at the center of the fan, sucking the oil smoke under the range hood into the fan. After being accelerated by the fan, it is collected by the volute and guided to be discharged outdoors.

[0003] In order to improve the oil fume absorption effect, a commonly used method is to set a smoke guide plate that can be raised and lowered.

[0004] For example, a smoke guide plate lifting mechanism for a range hood disclosed in Chinese patent application number 201720875268.9 provides a smoke guide plate lifting mechanism for a range hood that can offset the influence of load gravity when the lifting mechanism moves up and down; a counterweight device is provided on each side of the mounting frame to offset the influence of load gravity of the lifting mechanism; another example is a position determination method and a control method for a range hood and its lifting components disclosed in Chinese patent application number 202010397765.9, which provides a lifting range hood that can realize arbitrary position state judgment without adding multiple position sensors and wires, and can avoid the problem of changes in operating time due to wear and tear after long-term use.

[0005] However, the above range hoods all require a mechanical limit device to keep the range hood at a predetermined position, which increases product cost.

[0006] For example, the Chinese patent application number 202010397765.9 of the present applicant discloses a position determination method and a control method for a range hood and its lifting components, which provides a lifting range hood that can realize arbitrary position state judgment without adding multiple position sensors and wires. The patent calculates the descent distance by controlling the rotation angle of the motor.

[0007] After the range hood is turned on, as the oil smoke rises, the resistance of the rising smoke guide plate will gradually increase due to the influence of the oil smoke fluid; and the kitchen environment is bad, and as the use time increases, the oil stains adhere to it and the lifting mechanism wears, which will gradually increase the resistance load of the smoke guide plate. The control schemes of the above-mentioned prior art do not consider the changes in the descending speed and resistance caused by the change in load, which brings inconvenience to the experience. Summary of the invention

[0008] The first technical problem to be solved by the present invention is to provide a range hood to improve the uniformity of the lifting and lowering speeds of movable parts and enhance user experience in view of the deficiencies in the above-mentioned prior art.

[0009] The second technical problem to be solved by the present invention is to provide a control method for the above range hood.

[0010] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a range hood, including a movable part and a lifting mechanism for driving the movable part to lift, the lifting mechanism including a motor, characterized in that: the range hood also includes

[0011] The control module is electrically connected to the lifting motion mechanism and can obtain the resistance change of the movable part by monitoring the current output speed of the motor and adjust the current output speed or input power of the motor according to the resistance change.

[0012] Preferably, the range hood is a ceiling-type range hood, and the range hood further comprises a smoke collecting hood, an air inlet is provided on the smoke collecting hood, and the movable component is a smoke guide plate arranged below the air inlet.

[0013] Preferably, the range hood is a ceiling-type range hood, and the range hood comprises a fume hood and a fan frame located above the fume hood, and the fume hood serves as a movable component.

[0014] The technical solution adopted by the present invention to solve the second technical problem is: a control method of the range hood as described above, characterized in that: the control method comprises the following steps:

[0015] 1) Start the range hood;

[0016] 2) The motor of the lifting mechanism starts to work, and the initial parameters of the motor are: input power P0, output speed n0;

[0017] 3) Monitor the current output speed n of the motor at regular intervals;

[0018] 4) Determine whether n0-n≤Δn is true. If so, the motor continues to work with the current parameters and returns to step 3); if not, adjust the motor input power P so that n0-n≤Δn is true, and when P=P 额 When the current output speed of the motor is reduced; wherein Δn is the upper limit of the difference between the initial output speed n0 of the motor and the current output speed n, P 额 is the rated power of the motor.

[0019] Further, adjusting the input power P of the motor so that n0-n≤Δn is established includes the following steps: adjusting the input power P of the motor = P0+k*ΔP, where ΔP is a preset input power adjustment unit value and k is a positive integer; when the input power P reaches P 额 Before the motor is started, the current output speed n of the motor is monitored, and then it is determined whether n0-n≤Δn is established. If so, the motor continues to work normally with the current parameters. If not, the input power P of the motor (31) is continued to be adjusted.

[0020] Furthermore, when the input power P of the motor is adjusted to P 额 , perform the following steps:

[0021] 7) Detect the current output speed n of the motor and determine whether n0-n≤Δn is established. If yes, the motor continues to work normally with the current parameters; if no, proceed to step 8);

[0022] 8) Keep the input power of the motor at this time as P 额 The output speed of the motor is unchanged, and the output speed of the motor is reduced to n'=n-Δn1, where Δn1 is the preset output speed adjustment unit value; and n' and n min Compare and judge n'=n min Is it true, where n min is the preset minimum motor output speed. If yes, control the moving part to stop moving. If not, return to step 7).

[0023] Compared with the prior art, the advantages of the present invention are: by regulating the power and output speed according to the load resistance, the uniformity of the descent speed can be ensured when the load increases, the stability and reliability of the lifting function can be improved, and the user experience can be enhanced; the load changes can be monitored according to the speed changes of the motor operation control, which is more real-time and direct, and does not require additional sensors, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of a range hood according to an embodiment of the present invention;

[0025] Figure 2 is a cross-sectional view of a range hood according to an embodiment of the present invention;

[0026] Figure 3 It is a schematic diagram of the exploded structure of the smoke guide plate and the lifting mechanism thereof of the range hood according to an embodiment of the present invention;

[0027] Figure 4 4 is a control flow chart of the range hood according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for illustration and should not be regarded as limitations. For example, "up" and "down" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, the features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0030] See also Figure 1 to Figure 3 , a range hood, which is a top-suction range hood in this embodiment, includes a smoke hood 1 and a smoke guide plate 2, the smoke guide plate 2 is arranged below the air inlet (not shown) opened on the smoke hood 1, and can be lifted and lowered relative to the smoke hood 1 through a lifting and motion mechanism 3. When the user turns on the machine, the smoke guide plate 2 first descends and opens to the corresponding position, and then turns on the fan or lighting fixture to enter the working state. In this embodiment, the smoke guide plate 2 serves as a lifting component, and the smoke hood 1 (and the fan frame 5 above it and the fan system in the fan frame 5) serves as a fixed component. Alternatively, the smoke guide plate 2 and the smoke hood 1 can also be used as a lifting component as a whole, and the fan frame 5 above the smoke hood 1 and the fan system in the fan frame 5 can be used as fixed components. This lifting scheme can be referred to the range hood disclosed in the Chinese patent application number 202010397762.5 of this application.

[0031] The following description is based on controlling the lifting position of the smoke guide plate 2. Alternatively, it can also be used to control the lifting position of the smoke hood 1 or other movable parts. The range hood also includes a lifting motion mechanism 3 for driving the smoke guide plate 2, including a motor 31, a worm gear assembly (not shown) arranged on the output shaft of the motor 31, and a screw 33 coaxially arranged with the worm wheel of the worm gear assembly and rotating synchronously. A slider 32 threadedly connected to the screw 33 can be sleeved on the outer periphery of the screw 33, and the slider 32 is directly or indirectly connected to the smoke guide plate 2, so that the smoke guide plate 2 can be driven to lift. The lifting motion mechanism 3 also includes a connecting plate 34, a lifting rod 35 and a guide rail 36. Specifically, the lifting motion mechanism 3 of the present application can refer to the applicant's prior application in China with application number 201611244546.7, which is the same as the prior application.

[0032] Alternatively, the lifting motion mechanism 3 may also adopt other existing technologies including linear drive modules, such as a combination of a motor, gear and rack, an electric push rod, etc., but all of them need to include a motor for providing driving force.

[0033] The range hood further includes a control module 4, which is electrically connected to the lifting mechanism 3, and can use existing conventional technical means to monitor and adjust the parameters of the motor 31, such as output speed, output torque, input power, etc., so that the difference between the current output speed n of the motor 31 and the initial output speed n0 of the motor 31 is maintained within a preset range, so that the lifting speed of the smoke guide plate 2 is maintained within a preset range. Preferably, the lifting speed of the smoke guide plate 2 fluctuates within ±5% compared with the preset uniform speed.

[0034] Under the working conditions of the range hood, the descending resistance of the descending device is constantly changing due to friction, oil stains, wear, wind resistance, etc. However, in order to ensure uniform running speed and better user experience, it is necessary to maintain a uniform speed under different loads.

[0035] For this purpose, see Figure 4 The range hood of the present invention adopts the following control method, which is implemented by controlling the lifting mechanism 3 through the control module 4, and specifically includes the following steps:

[0036] 1) Start the range hood;

[0037] 2) The motor 31 of the lifting mechanism 3 starts to work, and its initial parameters are: input power P0, output speed n0, the smoke guide plate 2 descends at a uniform speed and the speed is V0, and the output torque is T0;

[0038] 3) monitoring the current output speed n of the motor 31 at intervals of Δt;

[0039] 4) Determine whether n0-n≤Δn holds. If so, the motor 31 continues to work normally with the current parameters and returns to step 3); if not, it means that the load (smoke guide plate 2) resistance increases, and the smoke guide plate 2 starts to decelerate, and enters step 5); wherein Δn is the upper limit of the difference between the preset initial output speed n0 of the motor 31 and the current output speed n, and n0-n≤Δn holds, that is, the current output speed of the motor 31 is within the allowable range and can be regarded as uniform motion;

[0040] 5) Adjust the input power of the motor 31 to P = P0 + k*ΔP, and ensure that P ≤ P 额 , P 额 is the rated power; where ΔP is the preset input power adjustment unit value, k is a positive integer, and the maximum value is such that P = P 额 ;

[0041] 6) Determine P = P 额 Is it true? If so, it means that the input power of the motor 31 reaches the maximum value P 额 , the current output speed of motor 31 reaches the maximum value n max , go to step 7); if not, go to step 9);

[0042] 7) Detect the current output speed n of the motor 31 and determine whether n0-n≤Δn is established. If yes, the motor 31 continues to work normally with the current parameters; if no, proceed to step 8);

[0043] 8) Maintain the input power P of the motor 31 at this time 额 The output speed of the motor 31 is unchanged, and the output speed of the motor 31 is reduced to n'=n-Δn1, wherein Δn1 is a preset output speed adjustment unit value; and n' and n min Compare and judge n'=n min Is it true, where n min is the preset minimum output speed of the motor 31. If yes, then the output speed of the motor 31 reaches the minimum and the output torque reaches the maximum, reminding the user that the descending resistance is too large, then the lifting mechanism 3 stops, so that the smoke guide plate 2 stops moving. If no, return to step 7);

[0044] 9) Monitor the current output speed n of the motor 31 and determine whether n0-n≤Δn holds. If so, the motor 31 continues to work normally with the current parameters. If not, it means that the load resistance is large and the motor 31 is still decelerating, and return to step 5).

[0045] The above control method can ensure that the descent speed etc. will not produce large errors when the resistance changes, thereby improving the user experience.

Claims

1. A control method for a range hood, the range hood comprising a movable part and a lifting mechanism (3) for driving the movable part to lift, the lifting mechanism (3) comprising a motor (31); Features: The range hood also includes The control module (4) is electrically connected to the lifting mechanism (3), and is capable of obtaining a resistance change of the movable component by monitoring the current output speed of the motor (31), and adjusting the current output speed or input power of the motor (31) according to the resistance change; The control method comprises the following steps: 1) Start the range hood; 2) The motor (31) of the lifting mechanism (3) starts to work, and the initial parameters of the motor (31) are: input power P0, output speed n0; 3) monitoring the current output speed n of the motor (31) at regular intervals; 4) Determine whether n0-n≤Δn holds. If so, the motor (31) continues to operate with the current parameters, and then returns to step 3); if not, adjust the input power P of the motor (31) so that n0-n≤Δn holds, and when P=P 额 When the current output speed of the motor (31) is reduced, the following steps are specifically performed: 7) Detecting the current output speed n of the motor (31) and determining whether n0-n≤Δn holds. If so, the motor (31) continues to operate normally with the current parameters; if not, proceeding to step 8); 8) Keep the input power of the motor (31) at P 额 The output speed of the motor (31) is reduced to n'=n-Δn1, wherein Δn1 is a preset output speed adjustment unit value; and n' and n min Compare and judge n'=n min Is it true, where n min The motor (31) outputs a minimum speed value, if it is, the moving part is controlled to stop moving, if not, return to step 7); Wherein Δn is a preset upper limit value of the difference between the initial output speed n0 of the motor (31) and the current output speed n, P 额 is the rated power of the motor (31).

2. The control method of the range hood according to claim 1, characterized in that: Adjusting the input power P of the motor (31) so that n0-n≤Δn holds comprises the following steps: The input power P of the motor (31) is adjusted to P0+k*ΔP, where ΔP is a preset input power adjustment unit value and k is a positive integer; when the input power P reaches P 额 Before the motor (31) is turned on, the current output speed n of the motor (31) is monitored, and then it is determined whether n0-n≤Δn is established. If so, the motor (31) continues to work normally with the current parameters. If not, the input power P of the motor (31) continues to be adjusted.

3. The control method of the range hood according to claim 1, characterized in that: The range hood is a top-suction range hood, and further comprises a smoke collecting hood (1). An air inlet is provided on the smoke collecting hood (1), and the movable component is a smoke guide plate (2) arranged below the air inlet.

4. The control method of the range hood according to claim 1, characterized in that: The range hood is a top-suction range hood, comprising a fume hood (1) and a fan frame (5) located above the fume hood (1), and the fume hood (1) serves as a movable component.

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