A driving control method for a smoke baffle of a range hood and a range hood using the same

Abstract

A drive control method for a smoke damper of a range hood, characterized in that it includes the following steps: Step 1, initializing and setting the drive voltage Um of the smoke damper motor; Step 2, continuously sampling the back electromotive force voltage Ue on both sides of the smoke damper motor; Step 3, whether Ue is less than or equal to Um, if so, continue to execute the next step 4; if not, go to step 5; Step 4, the smoke damper is about to be closed, execute the anti-pinch subroutine, and go to step 6; Step 5, the smoke damper is in the normal closing process, return to step 3; Step 6, the program ends. The present invention also discloses a range hood that adopts the above-mentioned smoke damper drive control method. The advantages of the present invention are: low detection cost, simple operation and easy implementation; in addition, the problem of capacitor signal delay in the existing technology can be effectively avoided by detecting the back electromotive force method, so that the real-time detection is guaranteed, the detection result is highly accurate and consistent, and the equipment is safer and more reliable to use.

Description

Technical Field

[0001] The invention relates to a safety control method for a range hood, and in particular to a drive control method for a smoke baffle of a range hood and a range hood using the method. Background Art

[0002] In the prior art, the smoke shield of the range hood is mostly driven by a DC motor. Usually, the DC motor is connected to the smoke shield through a structural member. The motor rotates in different directions to drive the smoke shield to open or close.

[0003] However, the smoke shield is prone to accidents such as pinching fingers during the closing process. For this reason, the existing solutions are usually the following two methods: the first method is to implant a travel switch in the DC motor. The main control MCU determines whether the smoke shield has reached a specific position by detecting the state of the travel switch. When the travel switch meets the conditions, the main control MCU can execute the anti-pinch solution. However, the travel switch used in the first solution is expensive. When the range hood structure is different, the travel switch position of the small DC motor needs to be adjusted synchronously, and the versatility is poor; the second solution is to determine the position of the motor by detecting the running current of the DC motor. When the smoke shield is in place, if the DC motor is in a stalled state (i.e., a pinching finger or other events that jam the smoke shield may occur), the stalled current will be several times or even dozens of times higher than the running current. The position of the smoke shield can be determined by detecting the running current of the DC motor. However, the second solution has poor anti-finger pinching performance because the DC motor has poor consistency and the current detection can only detect the stalled state, that is, the smoke shield has been in place or the smoke shield has clamped the user's arm. At this time, it is too late to feedback the information, and it will still cause a finger pinching safety accident, resulting in a poor user experience.

[0004] In addition, for example, the Chinese utility model patent No. 201620475620.5 "A Finger-Preventing Range Hood" discloses an anti-finger-pinching range hood, which includes a body and a main control unit. The body includes a casing, a smoke baffle arranged at the front of the casing and an electric eaves arranged above the smoke baffle. The electric eaves include an eaves panel hinged on the casing and a driving mechanism for driving the eaves panel to flip. A capacitive sensor is provided on the eaves panel, which is electrically connected to the main control unit. During the closing process of the eaves panel, the main control unit performs safety detection based on the capacitance mutation signal fed back by the capacitive sensor, and performs protection control on the range hood.

[0005] The implementation principle of the above patent is that when the eaves panel is closed, if the user's hand reaches into the area between the eaves panel and the casing, an induced capacitor will be generated on the capacitive sensing element, thereby breaking the linear change of the capacitance when the eaves panel is normally closed, resulting in a sudden change in the capacitance detection signal. The main control unit detects the capacitance mutation signal and can determine that the eaves panel is abnormally closed, thereby protecting and controlling the range hood. However, the charging and discharging process of the capacitor is actually the change of the capacitor voltage, but the voltage across the capacitor cannot change suddenly. The change of the capacitor voltage requires a certain amount of time. There will be a certain delay or lag in obtaining the sudden change of the capacitor detection signal, which will still cause the user's hand to be caught. In actual applications, the safety and reliability of the range hood cannot be guaranteed.

[0006] In summary, the existing smoke baffle driving control method cannot solve the problem of safety in use well, and further improvement and perfection are needed. Summary of the invention

[0007] The first technical problem to be solved by the present invention is to provide a driving control method for a smoke baffle of a range hood with good versatility, low implementation cost and better anti-pinching effect in response to the above-mentioned existing technical status.

[0008] The second technical problem to be solved by the present invention is to provide a driving control method for a smoke baffle of a range hood with good versatility, low implementation cost and better anti-pinching effect in response to the above-mentioned existing technical status.

[0009] The technical solution adopted by the present invention to solve the above-mentioned first technical problem is: a driving control method for a smoke baffle of a range hood, characterized in that the range hood includes a smoke baffle motor capable of driving the smoke baffle to move, and the driving control method includes the following steps:

[0010] Step 1: Start the program, initialize the settings, and set the driving voltage Um of the smoke baffle motor;

[0011] Step 2: The smoke shield is closed and started, and the back electromotive force voltage Ue on both sides of the smoke shield motor is continuously sampled;

[0012] Step 3: The main control chip determines whether the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke shield motor. If yes, proceed to step 4; if not, go to step 5;

[0013] Step 4: The smoke shield is about to be closed, execute the finger pinch prevention subroutine, and go to step 6;

[0014] Step 5: The smoke baffle is in the normal closing process, and return to step 3;

[0015] Step 6: The program ends.

[0016] In order to reduce the interference of other signals and improve the accuracy of detection, preferably, the following step 2-1 is included between step 2 and step 3: signal filtering is performed on the back electromotive force voltage Ue sampled in step 2 to obtain the filtered back electromotive force voltage Uf; accordingly, the main control chip in step 3 determines whether the filtered back electromotive force voltage Uf is less than or equal to the driving voltage Um of the smoke damper motor, and if so, proceeds to the next step 4; if not, goes to step 5.

[0017] Taking into account the sensitivity or stability of the filtering result, preferably, the signal filtering of the back electromotive force voltage Ue may adopt a sliding window filtering algorithm or a first-order low-pass filtering algorithm.

[0018] In order to quickly and conveniently obtain the magnitude of the back electromotive force voltage, as a further preferred embodiment, the step 3 of determining whether the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke shield motor can be achieved by the following method:

[0019] A. The magnitude and direction of the driving voltage output by the main control chip. The driving voltage is used as the working voltage of the driving circuit of the smoke shield motor to realize the action of the smoke shield motor;

[0020] B. Detect the current direction of the driving voltage. When the driving voltage and the current direction in the driving circuit of the smoke damper motor are opposite, the smoke damper motor is in the power generation mode, and the back electromotive force voltage Ue is greater than the driving voltage Um of the smoke damper motor; when the current direction of the driving voltage and the current direction in the driving circuit of the smoke damper motor are consistent, the smoke damper motor is in the electric mode, and the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke damper motor. Therefore, the magnitude of the back electromotive force voltage and the driving voltage can be quickly determined by sampling the current direction in the driving circuit of the smoke damper motor. The detection method is simple and reliable.

[0021] As a further preference, the main control chip in step A can control the direction and magnitude of the output drive voltage of the H-bridge chip through two PWM signals.

[0022] In order to be able to promptly know that the smoke shield has moved to a position where fingers are likely to be pinched, preferably, the finger pinch prevention subroutine in step 4 includes a finger pinch prevention prompt or warning.

[0023] In order to further improve the safety of use and prevent the smoke shield from falling quickly before closing, as a further preferred embodiment, the anti-pinch subroutine in step 4 also includes controlling the speed of the smoke shield motor within a set speed range. By controlling the speed of the smoke shield motor, the speed at which the smoke shield falls can be effectively controlled.

[0024] Preferably, the set speed range is: the speed of the smoke shield motor is controlled to be less than or equal to 15 mm / s. Therefore, after the smoke shield reaches the inflection point, according to safety regulations, the speed of the smoke shield motor is reduced, thereby slowing down the running speed of the smoke shield, which can effectively prevent the user's fingers from being pinched by the rapidly descending smoke shield and causing injuries, further improving the safety of use.

[0025] Preferably, the rated voltage of the smoke baffle motor is 12V.

[0026] The technical solution adopted by the present invention to solve the above-mentioned second technical problem is: a range hood, comprising a shell, an air inlet opened on the shell, and a smoke baffle arranged on the shell and capable of opening or closing the air inlet, characterized in that: the smoke baffle adopts the driving control method as described in the above claims to realize operation.

[0027] Compared with the prior art, the advantages of the present invention are: by utilizing the two different working modes of the smoke shield motor during the closing process of the range hood smoke shield, the inflection point of the smoke shield movement is obtained by detecting the back electromotive force of the motor, and there is no need to implant a travel switch in the control method, the detection cost is low, the operation is simple and easy to implement; in addition, the method of detecting the back electromotive force can effectively avoid the problem of capacitor signal delay in the existing technology, so that the real-time detection is guaranteed, the detection result is highly accurate and consistent, and the equipment is safer and more reliable to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of a range hood smoke baffle in a fully open position according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the smoke absorption and smoke shielding plate of the embodiment of the present invention when it is in the middle position.

[0030] Figure 3 It is a schematic diagram of the range fumes shielding plate of the embodiment of the present invention when it is close to the closed position.

[0031] Figure 4 This is a schematic diagram of the oil fume absorption and smoke shielding plate according to the embodiment of the present invention when it is about to be closed.

[0032] Figure 5 This is a schematic diagram of a back electromotive force detection circuit for a smoke baffle motor according to an embodiment of the present invention.

[0033] Figure 6 The present invention is a flow chart of a method for driving and controlling a smoke baffle of a range hood according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to the accompanying drawings.

[0035] The smoke damper 1 of this embodiment adopts the smoke damper movement mechanism of the range hood disclosed in the invention patent "A Range Hood" with patent number ZL202010789329.6 previously applied by the applicant. The closing process of the smoke damper is a process of first falling, then lifting and finally closing. The path of the smoke damper closing process is as follows: Figure 1 to Figure 4 As shown: Among them, Figure 1 is a schematic diagram of the smoke baffle 1 in a fully open position, Figure 2 is a schematic diagram when the smoke baffle 1 is in the middle position, Figure 3 is a schematic diagram of the smoke baffle 1 approaching the closed position, Figure 4 It is a schematic diagram of the smoke shield 1 being about to be closed. The smoke shield motor of this embodiment adopts a small DC motor with a rated voltage of 12V.

[0036] According to the motor voltage formula in the prior art, the heavier the load, the slower the motor speed, and the smaller the motor terminal voltage (back electromotive force); and the lighter the load, the faster the motor speed, and the larger the motor terminal voltage (back electromotive force). When the load is negative, that is, when the load drags the motor to run, the motor terminal voltage (back electromotive force) is close to the applied voltage, or even greater than the applied voltage.

[0037] Therefore, using the characteristics of DC motor, Figure 1 to Figure 3 During the movement, the gravity direction of the smoke shield is consistent with the movement direction of the smoke shield motor, that is, the smoke shield (load) drags the motor to run, and the smoke shield motor is in light load mode; Figure 3-4 During the operation, the gravity direction of the smoke damper is opposite to the movement direction of the smoke damper motor, that is, the smoke damper motor drags the smoke damper (load) to operate, and the smoke damper motor is in the heavy load mode.

[0038] Therefore, during the operation of the smoke damper motor of the present embodiment, when the smoke damper is in different positions, the load of the smoke damper motor is different, the movement speed of the smoke damper motor is also different, and the smoke damper (load) has a turning point (the motor load changes from light to heavy). The present application selects this turning point as a reference position point, and determines whether the smoke damper is about to close in place by detecting the turning point.

[0039] The range hood smoke baffle driving control method of this embodiment includes the following steps: Figure 6 :

[0040] Step 1: Start the program, initialize the settings, and set the driving voltage Um of the smoke shield motor. The driving voltage Um here is not a constant, but changes with time. Depending on the position of the smoke shield, the corresponding motor load size changes. The driving voltage Um can be calibrated in advance and written into the program.

[0041] Step 2: The smoke damper closing command is started, and the back electromotive force voltage Ue on both sides of the smoke damper motor is continuously sampled;

[0042] Step 3: The main control chip determines whether the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke baffle motor. If so, proceed to the next step 4; if not, go to step 5.

[0043] Step 4: The smoke shield is about to close in place, execute the anti-pinch subroutine, and go to step 6.

[0044] Step 5: The smoke damper is in the normal closing process, return to step 3.

[0045] Step 6: The program ends.

[0046] This embodiment also discloses a range hood, comprising a shell, an air inlet opened on the shell, and a smoke baffle disposed on the shell and capable of opening or closing the air inlet. The smoke baffle operates using the drive control method described above.

[0047] Among them, in order to improve the accuracy of signal acquisition and prevent interference from other signals, the following step 2-1 can also be included between step 2 and step 3: perform signal filtering on the back electromotive force voltage Ue sampled in step 2 to obtain the filtered back electromotive force voltage Uf; accordingly, the main control chip in step 3 determines whether the filtered back electromotive force voltage Uf is less than or equal to the driving voltage Um of the smoke shield motor, if so, continue to execute the next step 4; if not, go to step 5. Preferably, the signal filtering of the back electromotive force voltage Ue can specifically adopt a sliding window filtering algorithm or a first-order low-pass filtering algorithm.

[0048] The signal filtering scheme of the back electromotive force voltage Ue in this embodiment can adopt the following two existing filtering methods. One is software RC filtering, that is, a first-order low-pass filtering algorithm. The first-order low-pass filtering formula is: V filter =(1-k)×V filter +V ad , where V ad is the voltage sampling value, V filter is the output voltage after the first-order low-pass filter, k is the filter coefficient, 0<k<1, the smaller k is, the deeper the filter depth is;

[0049] The other is the sliding window filtering algorithm. The principle of sliding window filtering is: the sampling value at the kth moment is V k ', the time window filter output is V k ,but Among them, n is the length of the sliding time window, and the larger n is, the deeper the filtering depth is.

[0050] In order to facilitate detection and reduce detection costs, as a preferred embodiment, the sampling of the back electromotive force voltage in step 2 of this embodiment and the determination of whether the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke shield motor in step 3 can be achieved by the following method:

[0051] A. The main control chip controls the direction and magnitude of the H-bridge chip output drive voltage through two PWM signals. The drive voltage is used as the working voltage of the drive circuit of the smoke shield motor to realize the action of the smoke shield motor. Figure 5 The schematic diagram of the back electromotive force detection circuit shown;

[0052] B. Detect the current direction of the driving voltage. When the driving voltage and the current direction in the driving circuit of the smoke shield motor are opposite, the smoke shield motor is in light load mode, and the back electromotive force voltage Ue is greater than the driving voltage Um of the smoke shield motor; when the current direction of the driving voltage and the current direction in the driving circuit of the smoke shield motor are consistent, the smoke shield motor is in heavy load mode, and the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke shield motor.

[0053] Therefore, by sampling the current direction in the driving circuit of the smoke shield motor, the magnitude of the back electromotive force voltage and the driving voltage can be quickly determined. The detection method is simple, direct, fast and reliable.

[0054] The anti-pinch subroutine in the above control method can adopt various methods. As a preference, the anti-pinch subroutine can include an anti-pinch prompt or warning, that is, when the smoke damper is about to reach the closed position, the user can be reminded, and the reminder can be in various ways such as light warning or sound prompt; when the smoke damper reaches the inflection point until it is completely closed, the load will change with the position, so the driving voltage value in this stage is not a constant, but changes with time. The driving voltage in this stage can be calibrated in advance. When the inflection point appears, the driving voltage can be given in a linear rise from V1 to V2 (from the inflection point to the moment of complete closure). At the same time, according to safety regulations, the anti-pinch subroutine can also be set to control the speed of the smoke damper motor within a set speed range. After the smoke damper reaches the inflection point, the speed of the smoke damper motor can be controlled within a speed range of less than or equal to 15mm / s, that is, by reducing the voltage driving the smoke damper motor, thereby reducing the speed and torque of the smoke damper motor, it can effectively prevent the occurrence of finger pinching accidents when the smoke damper falls to the position about to be closed, thereby improving the safety and reliability of the range hood equipment.

[0055] This embodiment determines the position of the smoke shield by detecting the back electromotive force of the smoke shield motor and the size of the driving voltage. When the smoke shield is in different moving positions, the load of the motor is different: when the load drives the motor to move, the back electromotive force of the motor is greater than the voltage applied to the motor; when the motor drives the load to move, the back electromotive force of the motor is less than or equal to the voltage applied to the motor; thus, a signal of a change in the back electromotive force can be detected, and then the inflection point of the smoke shield movement can be found, thereby realizing anti-pinch protection. The detection method of this embodiment does not require the addition of additional detection equipment, has low detection cost, is easy to implement, and has good consistency in detection results.

Claims

1. A driving control method for a smoke baffle of a range hood, characterized in that: The range hood includes a smoke baffle motor capable of driving the smoke baffle to move, and the drive control method includes the following steps: Step 1: Start the program, initialize the settings, and set the driving voltage Um of the smoke baffle motor; Step 2: The smoke shield is closed and started, and the back electromotive force voltage Ue on both sides of the smoke shield motor is continuously sampled; Step 3: The main control chip determines whether the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke shield motor. If yes, proceed to step 4; if not, go to step 5; Step 4: The smoke shield is about to be closed, execute the finger pinching prevention subroutine, and go to step 6; Step 5: The smoke baffle is in the normal closing process, and return to step 3; Step 6: The program ends.

2. The driving control method of the smoke baffle of a range hood according to claim 1, characterized in that: The following step 2-1 is also included between step 2 and step 3: performing signal filtering on the back electromotive force voltage Ue sampled in step 2 to obtain the filtered back electromotive force voltage Uf; accordingly, the main control chip in step 3 determines whether the filtered back electromotive force voltage Uf is less than or equal to the driving voltage Um of the smoke shield motor, and if so, proceeds to the next step 4; if not, goes to step 5.

3. The driving control method of the smoke baffle of a range hood according to claim 2, characterized in that: The signal filtering of the back electromotive force voltage Ue adopts a sliding window filtering algorithm or a first-order low-pass filtering algorithm.

4. The driving control method of the smoke baffle of a range hood according to claim 1, characterized in that: In step 3, judging whether the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke baffle motor is achieved by the following method: A. The magnitude and direction of the driving voltage output by the main control chip. The driving voltage is used as the working voltage of the driving circuit of the smoke shield motor to realize the action of the smoke shield motor; B. Detect the current direction of the driving voltage. When the driving voltage and the current direction in the driving circuit of the smoke damper motor are opposite, the smoke damper motor is in the power generation mode, and the back electromotive force voltage Ue is greater than the driving voltage Um of the smoke damper motor; when the current direction of the driving voltage and the current direction in the driving circuit of the smoke damper motor are consistent, the smoke damper motor is in the electric mode, and the back electromotive force voltage Ue is less than or equal to the driving voltage Um of the smoke damper motor.

5. The driving control method of the smoke baffle of a range hood according to claim 1, characterized in that: The main control chip in step A controls the direction and magnitude of the output drive voltage of the H-bridge chip through two PWM signals.

6. The driving control method of the smoke baffle of a range hood according to claim 1, characterized in that: The finger pinch prevention subroutine in step 4 includes a finger pinch prevention prompt or warning.

7. The driving control method of the smoke baffle of a range hood according to claim 1, characterized in that: The finger pinch prevention subroutine in step 4 also includes controlling the rotation speed of the smoke baffle motor within a set rotation speed range.

8. The driving control method of the smoke baffle of a range hood according to claim 7, characterized in that: The set speed range is: the speed of the smoke baffle motor is controlled to be less than or equal to 15 mm / s.

9. The driving control method of the smoke baffle of a range hood according to claim 1, characterized in that: The rated voltage of the smoke baffle motor is 12V.

10. A range hood, comprising a housing, an air inlet provided on the housing, and a smoke baffle provided on the housing and capable of opening or closing the air inlet, characterized in that: The smoke baffle is operated by the driving control method described in any one of claims 1 to 9 above.

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