Range hood and control method thereof

Abstract

The present invention discloses a range hood and a control method thereof, the range hood comprising a box body, a first smoke baffle and a second smoke baffle being arranged at the bottom of the box body, the first smoke baffle corresponding to the air inlet area on the left side of the bottom of the box body, and the second smoke baffle corresponding to the air inlet area on the right side of the bottom of the box body; the range hood comprises a motion mechanism for driving the first smoke baffle and the second smoke baffle to translate in the left and right directions so as to open and close the corresponding air inlet areas; the motion mechanism comprises a driving mechanism and a transmission mechanism, the driving mechanism having an output shaft extending forward and backward, the transmission mechanism comprising a gear rotating synchronously with the output shaft, a first rack fixed to the first smoke baffle and a second rack fixed to the second smoke baffle, the first rack and the second rack being respectively arranged on the upper and lower sides of the gear; the gear is arranged on the output shaft and can move axially relative to the output shaft, so that it can selectively engage with at least one of the first rack and the second rack, so that the two smoke baffles translate independently or synchronously.

Description

Technical Field

[0001] The present 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 an indispensable kitchen appliance in modern homes. They operate based on the principles of fluid dynamics, using a centrifugal fan installed inside the hood to draw in and exhaust cooking fumes, while a filter removes some grease particles. A centrifugal fan consists of a volute, an impeller mounted within the volute, and a motor that drives the impeller. As the impeller rotates, negative pressure is generated at the fan's center, drawing cooking fumes from beneath the hood into the fan. After being accelerated by the fan, the volute collects them and guides them out of the room.

[0003] To improve smoke collection, range hoods typically feature a smoke shield at the air inlet. When the range hood is in operation, the shield opens to expand the smoke collection area. For example, Chinese Patent Application No. 201120023736.2 discloses a left-right, dual-door range hood that includes a wind cabinet, an outer decorative cover, an inner decorative cover, a smoke hood, an oil screen mounted on the hood, a front panel, and a control panel. The smoke hood includes a front frame and a front-opening smoke collection chamber. The front panel is divided into left and right panels.

[0004] In this type of range hood, the two smoke deflectors (panels) can only move synchronously. To achieve single-sided cooking with the air inlet open and close, independent motion mechanisms are typically required. Consequently, when both sides need to be opened or closed, synchronization is poor due to the independent motion mechanisms. In other words, in existing range hoods, the same motion mechanism cannot simultaneously achieve independent and synchronous movement of the two smoke deflectors, resulting in a poor user experience in actual use and warrants further improvement. Summary of the Invention

[0005] The first technical problem to be solved by the present invention is to provide a range hood in response to the deficiencies in the above-mentioned prior art, which can realize the independent movement of one side and the synchronous movement of both sides of the smoke baffle through a set of motion mechanisms, thereby improving user experience.

[0006] The second technical problem to be solved by the present invention is to provide a control method for the above range hood.

[0007] The technical solution adopted by the present invention to solve the first technical problem mentioned above is: a range hood, comprising a housing, wherein a first smoke shield and a second smoke shield are provided at the bottom of the housing, wherein the first smoke shield corresponds to the air inlet area on the left side of the bottom of the housing, and the second smoke shield corresponds to the air inlet area on the right side of the bottom of the housing;

[0008] The range hood includes a motion mechanism for driving the first smoke baffle and the second smoke baffle to move horizontally to open and close the corresponding air inlet areas; the characteristics are:

[0009] The motion mechanism includes a drive mechanism and a transmission mechanism, wherein the drive mechanism has an output shaft extending forward and backward, and the transmission mechanism includes a gear that rotates synchronously with the output shaft, a first rack fixed to the first smoke shield, and a second rack fixed to the second smoke shield, wherein the first rack and the second rack are respectively arranged on the upper and lower sides of the gear;

[0010] The gear is arranged on the output shaft and can move axially relative to the output shaft, so as to selectively engage with at least one of the first rack and the second rack, so that the two smoke shields can translate independently or synchronously.

[0011] By making the gears of the smoke shield's motion mechanism movable, the relative positions of the gears and the racks can be changed so that the gears engage with one of the racks or both racks. This allows for easy switching between single smoke shield and double smoke shield drive, and allows for single-sided independent motion and dual-sided synchronous motion of the smoke shield through a set of motion mechanisms, thereby improving user experience.

[0012] Furthermore, to facilitate the movement of the driving gear, the driving mechanism also includes a magnetic attraction component, which includes an electromagnet and a permanent magnet. The electromagnet is fixed in the box, and the output shaft passes through the electromagnet and the permanent magnet. The gear is fixed to the permanent magnet, and the gear is located on the side of the permanent magnet away from the electromagnet and is splined with the output shaft.

[0013] Furthermore, in order to facilitate the resetting of the gear, an elastic member is provided between the permanent magnet and the electromagnet, and the elastic member enables the gear to maintain a tendency to mesh with both the first rack and the second rack.

[0014] In order to facilitate the change of the meshing state between the gear and each rack when the gear moves, the first rack and the second rack are staggered in the front-to-back direction.

[0015] Furthermore, the first rack includes a first base and at least two first teeth provided on the first base, each first tooth being arranged in the left-right direction; the second rack includes a second base and at least two second teeth provided on the second base, each second tooth being arranged in the left-right direction;

[0016] The projections of the first tooth and the second tooth on the horizontal plane partially overlap along the front-to-back direction, thereby enabling the gear to mesh with one or both racks during the forward and backward movement.

[0017] Furthermore, to prevent the gear from getting stuck with the rack during movement and thus being unable to engage, the first teeth of the first rack and the second teeth of the second rack are sharp-angled at both ends along the width direction of each rack, thereby forming a first guide structure;

[0018] The gear includes a wheel body and at least two third teeth arranged along the circumference of the wheel body, and the corresponding two ends of each third tooth are also pointed, thereby forming a second guide structure.

[0019] To further ensure smooth switching of the gear rack, along the width direction of the first rack, the first base is provided with a first avoidance surface on the surface of the first tooth that is not covered by the first tooth, and along the width direction of the second rack, the second base is provided with a second avoidance surface on the surface of the second tooth that is not covered by the second tooth.

[0020] The technical solution adopted by the present invention to solve the second technical problem is: a control method for the range hood as described above, characterized in that the control method comprises the following steps:

[0021] 1) The range hood starts and runs in the default gear, with the two smoke baffles moving synchronously;

[0022] 2) Detect the oil smoke concentration ya in the air inlet area on the left side of the bottom of the box and the oil smoke concentration ya in the air inlet area on the right side, and compare ya and yb to see if there is a significant difference. If not, keep the default gear running; if so, go to step 3);

[0023] 3) Compare ya and yb. If ya>yb, proceed to step 4). If ya<yb, proceed to step 8).

[0024] 4) Check whether the first smoke baffle is fully opened. If yes, proceed to step 5); if no, proceed to step 6);

[0025] 5) The control gear is engaged with the second rack, and then the process proceeds to step 12);

[0026] 6) The control gear is engaged with the first rack; proceed to step 7);

[0027] 7) The driving mechanism pushes the first smoke baffle to move horizontally to the left;

[0028] 8) Check whether the second smoke baffle is fully opened. If yes, proceed to step 9); if no, proceed to step 10);

[0029] 9) The control gear is engaged with the first rack, and then the process proceeds to step 12);

[0030] 10) The control gear is engaged with the second rack;

[0031] 11) The driving mechanism pushes the second smoke shield to move horizontally to the right;

[0032] 12) Push the smoke shield corresponding to the rack currently meshing with the gear to move a certain distance toward the center; then wait for a certain time Δt and return to step 2).

[0033] Preferably, in step 2), the threshold value of difference discrimination is set to m, if It is considered that there is no significant difference if A significant difference is considered. The above ratio is used as the baseline for comparison because the oil fume concentration values detected by the oil fume sensor fluctuate significantly. This requires normalization to a specific range to facilitate factory default settings and comparison with the preset values. Therefore, it is considered to be converted to the range [0, 1] to facilitate setting the threshold m. Furthermore, the denominator is the value obtained by subtracting the oil fume concentration values detected by the two sensors. The magnitude of the denominator reflects the relative difference (large, small, or significant).

[0034] Furthermore, the driving mechanism is a motor. In step 12), the oil smoke concentration difference dy=|ya-yb| is calculated to determine the actual number of motor rotations R j '; The motor rotates counterclockwise R j ' circle, push the corresponding smoke baffle to move the corresponding distance towards the middle.

[0035] Furthermore, the actual number of motor rotations is preferably determined by presetting i different oil smoke concentration differences: dy1, dy2...dyi and j motor rotation numbers R1, R2...R j , and i=j, dyi and R j There is a one-to-one correspondence relationship. The current number of motor rotations R is calculated by interpolation using the preset correspondence relationship and the current real-time detected dy j , and then calculate R j ′=R j -R j-1 , where R j-1 The actual number of revolutions of the motor last time.

[0036] Preferably, to ensure safe operation, the driving mechanism is a motor. In step 7), the driving mechanism pushes the first smoke baffle to move to the left and then determines whether the motor current reaches the preset stall current value I d If yes, the motor is powered off and the process goes to step 5). If no, the process repeats. In step 11), the driving mechanism pushes the second smoke shield to the right and determines whether the motor current reaches the preset stall current value I. d If yes, the motor is powered off and the process goes to step 5). If no, repeat this step.

[0037] Compared with the existing technology, the advantages of the present invention are: by making the gear of the smoke shield's motion mechanism movable, the relative positions of the gear and each rack can be changed so that the gear is engaged with one of the racks or both racks are engaged, and it is convenient to switch between single smoke shield and double smoke shield drive, and the smoke shield can be driven by a set of motion mechanisms to achieve independent movement of one side and synchronous movement of both sides, thereby improving user experience; and the gear and rack switching method has a compact structure and basically does not occupy air duct space. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram of a range hood in a fully open state according to an embodiment of the present invention;

[0039] Figure 2 Schematic diagram of a smoke baffle assembly and its motion mechanism in a fully open state of a range hood according to an embodiment of the present invention;

[0040] Figure 3 for Figure 2 A schematic diagram of the partial I enlargement;

[0041] Figure 4 A partial schematic diagram of a driving mechanism of a range hood movement mechanism according to an embodiment of the present invention;

[0042] Figure 5 is a schematic diagram of the gears of the motion mechanism of the range hood according to an embodiment of the present invention;

[0043] Figure 6 is a schematic diagram of a rack of a motion mechanism of a range hood according to an embodiment of the present invention;

[0044] Figure 7 A side view of the smoke baffle assembly and its motion mechanism of the range hood in a fully open state according to an embodiment of the present invention;

[0045] Figure 8 for Figure 7 A schematic diagram of the partial II enlargement;

[0046] Figure 9 This is a schematic diagram of a range hood in a closed state according to an embodiment of the present invention;

[0047] Figure 10 This is a schematic diagram of a range hood in a left-open state according to an embodiment of the present invention;

[0048] Figure 11 Schematic diagram of a smoke baffle assembly and its motion mechanism of a range hood in a left-open state according to an embodiment of the present invention;

[0049] Figure 12 for Figure 11 A partial enlarged schematic diagram of Ⅲ;

[0050] Figure 13A side view of the smoke baffle assembly and its motion mechanism of the range hood in the left-open state according to an embodiment of the present invention;

[0051] Figure 14 for Figure 13 A partial enlarged schematic diagram of Ⅳ;

[0052] Figure 15 This is a schematic diagram of a range hood in a right-open state according to an embodiment of the present invention;

[0053] Figure 16 A side view of the smoke baffle assembly and its motion mechanism of the range hood in the right-open state according to an embodiment of the present invention;

[0054] Figure 17 for Figure 16 A partial enlarged schematic diagram of V;

[0055] Figure 18 This is a control flow chart of the range hood according to an embodiment of the present invention. DETAILED DESCRIPTION

[0056] 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.

[0057] 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 orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply 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, features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0058] See also Figures 1 to 8 A range hood includes a housing 1 with an air inlet 11 defined at the bottom. The air inlet 11 may be two independent, left and right inlets, or may be integral and divided into a left and right communicating area. A fan system (not shown) may be disposed within the housing 1 or located elsewhere and communicate with the housing 1.

[0059] A smoke deflector assembly is also provided at the bottom of the housing 1. The smoke deflector assembly includes a first smoke deflector 21 on the left side and a second smoke deflector 22 on the right side. The first and second smoke deflectors 21, 22 are preferably flat plates and arranged horizontally. The first smoke deflector 21 corresponds to the left air inlet 11 or the left side area of the air inlet 11 (i.e., the left air inlet area), and the second smoke deflector 22 corresponds to the right air inlet 11 or the right side area of the air inlet 11 (i.e., the right air inlet area).

[0060] When the first smoke baffle 21 and the second smoke baffle 22 are folded, the air inlet 11 is closed, and the first smoke baffle 21 preferably does not extend beyond the left side of the housing 1, and the second smoke baffle 22 preferably does not extend beyond the right side of the housing 1, thereby making the entire device smaller in the closed state. When the first smoke baffle 21 and the second smoke baffle 22 are unfolded, the first smoke baffle 21 moves horizontally to the left from its initial folded position and extends beyond the left side of the housing 1, thereby at least partially opening the left air inlet 11 or the left side area of the air inlet 11, and the second smoke baffle 22 moves horizontally to the right from its initial folded position and extends beyond the right side of the housing 1, thereby at least partially opening the right air inlet 11 or the right side area of the air inlet 11. At this time, the translation of the first smoke baffle 21 and the second smoke baffle 22 also expands the smoke collection area, which can reduce the escape of oil smoke from the left and right sides and improve the oil smoke absorption effect.

[0061] The range hood also includes a motion mechanism for driving the translation of the first and second smoke deflectors 21 and 22. This motion mechanism comprises a drive mechanism 31, a transmission mechanism, and a mounting bracket 33. In this embodiment, the drive mechanism 31 is a motor having an output shaft 311 extending horizontally in the front-to-back direction. The mounting brackets 33 preferably comprise two spaced-apart mounting brackets 33, which are used to mount the drive mechanism 31 and the transmission mechanism. The drive mechanism 31 is secured to one of the mounting brackets 33, preferably the rear mounting bracket 33. The end of the output shaft 311 passes through the mounting bracket 33, thereby being rotatably supported thereon.

[0062] The drive mechanism 31 also includes a magnetic assembly, which includes an electromagnet 312 and a permanent magnet 313. The electromagnet 312 is fixed to the mounting bracket 33, and the output shaft 311 passes through the electromagnet 312 and the permanent magnet 313. Preferably, there are two sets of magnetic assemblies, with one electromagnet 312 positioned on each mounting bracket 33. Wires from the electromagnets 312 can be connected to the range hood's power board (typically located at the top of the housing 1), thereby energizing the electromagnets 312. The range hood's main control board can control whether the electromagnets 312 are energized in the forward direction, reverse direction, or not energized.

[0063] The transmission mechanism preferably comprises two groups, one group being provided on each mounting bracket 33. Each transmission mechanism group includes a gear 321, a first rack 322, and a second rack 323. The gear 321 is provided on the output shaft 311 so as to rotate with the output shaft 311. The first rack 322 and the second rack 323 are both slidably connected to the mounting bracket 33. One of the first rack 322 and the second rack 323 is positioned above the gear 321 and can mesh with the gear 321, thereby enabling left-right movement. The other of the first rack 322 and the second rack 323 is positioned below the gear 321 and can mesh with the gear 321, thereby enabling left-right movement. The effective width of the first rack 322 and the second rack 323 (referring to the width of the teeth on the rack) is greater than that of the gear 321. The first rack 322 includes a first base 3221 and at least two first teeth 3222 provided on the first base 3221, each of the first teeth 3222 being arranged in the left-right direction. The second rack 323 includes a second base 3231 and at least two second teeth 3232 provided on the second base 3231 , and the second teeth 3232 are arranged in the left-right direction.

[0064] The first rack 322 is fixed to the first smoke baffle 21, and the second rack 323 is fixed to the second smoke baffle 22. Since the two racks are located inside the housing 1, while the two smoke baffles are located outside the bottom of the housing 1, the first smoke baffle 21 is fixed to the first rack 322 via the first smoke baffle bracket 211, and the second smoke baffle 22 is fixed to the second rack 323 via the second smoke baffle bracket 221. In this embodiment, the second rack 323 is located above the first rack 322. The first rack 322 and the second rack 323 are staggered in the front-to-back direction, and the projections of the first rack 3222 and the second rack 3232 on the horizontal plane partially overlap in the front-to-back direction. "Staggered" here means that the projections on the horizontal plane partially overlap and partially do not overlap.

[0065] The permanent magnet 313 is fixed to the gear 321, and the gear 321 is located on the side of the permanent magnet 313 away from the electromagnet 312. As a result, the gear 321 can move along the output shaft 311 with the permanent magnet 313, thereby changing the meshing state with the two racks. To enable the gear 321 to both move axially relative to the output shaft 311 and rotate with the output shaft 311, the gear 321 and the output shaft 311 can be splined. An elastic member 314, such as a spring, is provided between the permanent magnet 313 and the electromagnet 312.

[0066] When the electromagnet 312 is energized in the forward direction, a repulsive force is generated between the electromagnet 312 and the permanent magnet 313. The repulsive force pushes the permanent magnet 313 and the gear 321 away from the electromagnet 312. As a result, the elastic member 314 is stretched, and the gear 321 is only engaged with the second rack 323 above. At this time, the driving mechanism 31 can only drive the second rack 323 (the second smoke shield 22 is translated). Figures 15 to 17 When the electromagnet 312 is not energized, the elastic member 314 returns to its natural state, and the position of the gear 321 is such that it meshes with both racks. Figure 7 and Figure 8 At this time, the driving mechanism 31 can simultaneously drive the first rack 322 (first smoke baffle 21) and the second rack 323 (second smoke baffle 22) to translate synchronously, see Figure 1 , drive the two smoke dampers to open synchronously, see Figure 9 , and can also drive the two smoke shields to close synchronously. When the electromagnet 312 is energized in the reverse direction, an attractive force is generated between the electromagnet 312 and the permanent magnet 313. The generated attractive force draws the permanent magnet 313 and the gear 321 toward the electromagnet 312. As a result, the elastic member 314 is compressed. At this time, the gear 321 only meshes with the first rack 322 below. At this time, the driving mechanism 31 can only drive the first rack 322 (the first smoke shield 21 moves in translation). See Figures 10 to 14 .

[0067] The first teeth 3221 of the first rack 322 and the second teeth 3231 of the second rack 323 have sharp corners at both ends along the width direction of each rack, thereby forming a first guide structure 3224 (only the first guide structure 3224 of the first rack 322 is shown in the figure, and the second rack 323 is the same). The gear 321 has a circular wheel body 3213 and at least two third teeth 3211 arranged along the circumference of the wheel body 3213. The corresponding ends of each third tooth 3211 are also sharp corners, thereby forming a second guide structure 3212. Each sharp corner position constitutes a guide structure. Therefore, when the gear 321 moves back and forth, it can be easily guided into the tooth groove (the groove formed between two adjacent teeth) of the corresponding rack to avoid getting stuck.

[0068] Since the gear 321 switches between the two racks in the upper and lower planes, in order to achieve this function, the two racks need to be made into non-full racks with avoidance structures. That is to say, the first base 3221 is provided with a first avoidance surface 3223 on the surface of the first tooth 3222 that is not covered by the first tooth 3222 (in the rack width direction), and the second base 3231 is provided with a second avoidance surface 3233 on the surface of the second tooth 3232 that is not covered by the second tooth 3232 (in the rack width direction). Regardless of the state in which the gear 321 switches, it can be ensured that the gear 321 can be in meshing state with at least one of the racks before switching. When switching, the rack that is already in meshing state can provide a guiding effect. At the same time, the guide structure designed on the rack can ensure that the gear and rack switch smoothly. In addition, other existing linear drive methods can also be used to drive the gear 321 to move.

[0069] Oil smoke sensors a and b can be respectively provided on the left and right sides of the air inlet 11 of the range hood to detect the oil smoke concentration on the corresponding side. This method of detecting the oil smoke concentration can adopt existing technology.

[0070] See also Figure 18 The control method of the present invention comprises the following steps:

[0071] 1) The range hood starts and runs in the default gear, with the two smoke baffles moving synchronously;

[0072] 2) Read the information ya of oil smoke sensor a and the information ya of oil smoke sensor b, and compare whether there is a significant difference between the values detected by the two oil smoke sensors. If there is no significant difference, keep the default gear running. If there is a significant difference, go to step 3); in this step, set the difference judgment threshold to m. If It is considered that there is no significant difference if It is considered that there is a significant difference; m can be obtained by simulating conventional cooking conditions (such as stir-frying on one side and not cooking or steaming on the other side);

[0073] 3) Compare ya and yb. If ya>yb, proceed to step 4). If ya<yb, proceed to step 8).

[0074] 4) Detect whether the first smoke baffle 21 is opened to the maximum, if yes, proceed to step 5), if not, proceed to step 6);

[0075] 5) The electromagnet 312 is energized in the forward direction, pushing the gear 321 away, so that the gear 321 engages with the second rack 323, and then proceeds to step 12);

[0076] 6) The electromagnet 312 is reversely energized to attract the gear 321, causing the gear 321 to mesh with the first rack 322; then proceed to step 7);

[0077] 7) The driving mechanism 31 (motor) rotates, as shown in FIG. Figure 4 The clockwise rotation shown in FIG. pushes the first smoke baffle 21 to move to the left; then determines whether the motor running current reaches the preset stall current value I d If yes, it means that the first smoke deflector 21 is fully opened, and the motor is powered off to prevent the motor from being blocked and hindering the forward and backward movement of the gear 321. It also prevents the motor from being blocked for a long time, causing the motor to overheat and reduce the driving force. Then, proceed to step 5. If no, it means that the first smoke deflector 21 is not fully opened, and repeat this step.

[0078] 8) Check whether the second smoke baffle 22 is opened to the maximum, if yes, proceed to step 9), if not, proceed to step 10);

[0079] 9) The electromagnet 312 is reversely energized to attract the gear 321, causing the gear 321 to mesh with the first rack 322, and then proceeding to step 12);

[0080] 10) The electromagnet 312 is energized in the forward direction, pushing the gear 321 away, causing the gear 321 to mesh with the second rack 323;

[0081] 11) The driving mechanism 31 (motor) rotates, as shown in FIG. Figure 4 The counterclockwise rotation shown in FIG. pushes the second smoke baffle 22 to move rightward; then determines whether the motor running current reaches the preset stall current value I d If yes, it means that the second smoke shield 22 is fully opened, and the motor is powered off to prevent the motor from being blocked and hindering the forward and backward movement of the gear 321. It also prevents the motor from being blocked for a long time, causing the motor to overheat and reduce the driving force. Then, proceed to step 9). If no, it means that the second smoke shield 22 is not fully opened, and repeat this step.

[0082] 12) Calculate dy = |ya-yb| and perform interpolation to determine the actual number of motor rotations R j '; The motor rotates counterclockwise R j ' circle, push the corresponding smoke baffle to move the corresponding distance in the middle direction; then wait for a certain time Δt and return to step 2).

[0083] In the above step 12), dy and R can be pre-set j For example, dy has i different preset values: dy1, dy2, dy3... dyi, R j There are j different preset values: R1, R2, R3...R j ; dy1 corresponds to R1, dy2 corresponds to R2... dyi corresponds to R j, i = j. The preset value here can be obtained through experiments, such as simulating actual cooking conditions and adjusting the number of motor rotations to achieve the desired oil smoke absorption effect (the effect of preventing oil smoke from escaping).

[0084] Optionally, if the number of rotations of the motor has five gears, that is, i=j=5, after the motor rotates R5 circles, each smoke baffle can be operated from fully open to fully closed.

[0085] After calculating the real-time dy, the position of dy in the preset gear is checked and interpolation is performed to determine the number of motor rotations R. For example, if the first detected oil smoke concentration difference dy is between the preset dy2 and dy3, using linear interpolation as an example, the corresponding number of motor rotations R satisfies the following calculation formula, which can be obtained through calculation:

[0086]

[0087] Here R j The number of revolutions of the motor when the system adjusts the position of the first smoke deflector or the second smoke deflector for the first time.

[0088] When the difference in oil smoke concentration between the left and right sides is detected for the second time, for example, if the dy detected this time is between the preset dy3 and dy4, then the interpolation calculation is continued, and the number of motor rotations obtained this time is R j According to the preset gear setting, the number of revolutions of the motor this time should be greater than the first time. Since the motor has already rotated a certain number of revolutions last time, this time it only needs to rotate R based on the last time. j -R j-1 , where R j-1 The number of revolutions of the last motor:

[0089]

Claims

1. A range hood, comprising a housing (1), wherein a first smoke baffle (21) and a second smoke baffle (22) are provided at the bottom of the housing (1), wherein the first smoke baffle (21) corresponds to an air inlet area on the left side of the bottom of the housing (1), and the second smoke baffle (22) corresponds to an air inlet area on the right side of the bottom of the housing (1); The range hood comprises a motion mechanism for driving a first smoke baffle (21) and a second smoke baffle (22) to move horizontally in a left-right direction so as to open and close corresponding air inlet areas; and is characterized in that: The motion mechanism includes a driving mechanism (31) and a transmission mechanism. The driving mechanism (31) includes a magnetic attraction component and an output shaft (311) extending forward and backward. The magnetic attraction component includes an electromagnet (312) and a permanent magnet (313). The electromagnet (312) is fixed in the box (1). The output shaft (311) passes through the electromagnet (312) and the permanent magnet (313). The transmission mechanism comprises a gear (321) that rotates synchronously with the output shaft (311), a first rack (322) fixed to the first smoke shield (21), and a second rack (323) fixed to the second smoke shield (22), wherein the first rack (322) and the second rack (323) are respectively arranged on the upper and lower sides of the gear (321); the gear (321) is fixed to the permanent magnet (313), and the gear (321) is located on the side of the permanent magnet (313) away from the electromagnet (312). The gear (321) is arranged on the output shaft (311) and is spline-matched with the output shaft (311) so as to be able to move axially relative to the output shaft (311), thereby being able to selectively mesh with at least one of the first rack (322) and the second rack (323); an elastic member (314) is provided between the permanent magnet (313) and the electromagnet (312); the elastic member (314) enables the gear (321) to maintain a tendency to mesh with both the first rack (322) and the second rack (323); When the electromagnet (312) is energized in the forward direction, a repulsive force is generated between the electromagnet (312) and the permanent magnet (313), the elastic member (314) is stretched, the gear (321) is only meshed with the second rack (323), and the driving mechanism (31) can only drive the second smoke shield (22) to translate; when the electromagnet (312) is not energized, the elastic member (314) is in a natural state, the gear (321) is meshed with both racks, and the driving mechanism (31) drives the first smoke shield (21) and the second smoke shield (22) to translate synchronously; when the electromagnet (312) is energized in the reverse direction, an attractive force is generated between the electromagnet (312) and the permanent magnet (313), the elastic member (314) is compressed, the gear (321) is only meshed with the first rack (322), and the driving mechanism (31) can only drive the first smoke shield (21) to translate.

2. The range hood according to claim 1, characterized in that: The first rack (322) and the second rack (323) are staggered in the front-to-back direction.

3. The range hood according to claim 2, characterized in that: The first rack (322) includes a first base (3221) and at least two first teeth (3222) provided on the first base (3221), and each first tooth (3222) is arranged in the left-right direction; the second rack (323) includes a second base (3231) and at least two second teeth (3232) provided on the second base (3231), and each second tooth (3232) is arranged in the left-right direction; The projections of the first tooth (3222) and the second tooth (3232) on the horizontal plane partially overlap in the front-to-back direction.

4. The range hood according to claim 3, characterized in that: The first teeth (3222) of the first rack (322) and the second teeth (3232) of the second rack (323) are sharp-angled at both ends of each tooth along the width direction of each rack, thereby forming a first guide structure (3224); The gear (321) includes a wheel body (3213) and at least two third teeth (3211) arranged along the circumference of the wheel body (3213), and the corresponding two ends of each third tooth (3211) are also pointed, thereby forming a second guide structure (3212).

5. The range hood according to claim 3, characterized in that: Along the width direction of the first rack (322), the first base (3221) is provided with a first avoidance surface (3223) on the surface of the first tooth (3222) that is not covered by the first tooth (3222); along the width direction of the second rack (323), the second base (3231) is provided with a second avoidance surface (3233) on the surface of the second tooth (3232) that is not covered by the second tooth (3232).

6. A control method for a range hood according to any one of claims 1 to 5, characterized in that: The control method comprises the following steps: 1) The range hood starts and runs in the default gear, with the two smoke baffles moving synchronously; 2) Detect the oil smoke concentration ya in the left air inlet area and the oil smoke concentration ya in the right air inlet area of the bottom of the box (1), and compare ya and yb to see if there is a significant difference. If not, keep the default gear running; if so, go to step 3); 3) Compare ya and yb. If ya>yb, proceed to step 4). If ya<yb, proceed to step 8). 4) Detecting whether the first smoke baffle (21) is opened to the maximum, if yes, proceeding to step 5), if not, proceeding to step 6); 5) Control the gear (321) to engage with the second rack (323), and then proceed to step 12); 6) The control gear (321) is engaged with the first rack (322); Go to step 7); 7) The driving mechanism (31) pushes the first smoke baffle (21) to move horizontally to the left; 8) Detect whether the second smoke baffle (22) is opened to the maximum, if yes, proceed to step 9), if not, proceed to step 10); 9) Control the gear (321) to engage with the first rack (322), and then proceed to step 12); 10) The control gear (321) is engaged with the second rack (323); 11) The driving mechanism (31) pushes the second smoke shield (22) to move horizontally to the right; 12) Push the smoke shield corresponding to the rack currently meshed with the gear (321) to move a certain distance toward the center; then wait for a certain time Δt and return to step 2).

7. The range hood control method according to claim 6, characterized in that: In step 2), the threshold value of difference discrimination is set to m. If It is considered that there is no significant difference if It is considered that there is a significant difference.

8. The range hood control method according to claim 6, characterized in that: The driving mechanism (31) is a motor. In step 12), the oil smoke concentration difference dy=|ya-yb| is calculated to determine the actual number of rotations R of the motor. j '; The motor rotates counterclockwise R j ' circle, push the corresponding smoke baffle to the middle direction and move the corresponding distance.

9. The range hood control method according to claim 8, characterized in that: Preset i different oil smoke concentration differences: dy1, dy2...dyi and j motor rotation numbers R1, R2...R j , and i=j, dyi and R j There is a one-to-one correspondence relationship. The current number of motor rotations R is calculated by interpolation using the preset correspondence relationship and the current real-time detected dy j , and then calculate R j ′=R j -R j-1 , where R j-1 The actual number of revolutions of the motor last time.

10. The range hood control method according to claim 6, characterized in that: The driving mechanism (31) is a motor. In step 7), the driving mechanism (31) pushes the first smoke baffle (21) to move horizontally to the left and then determines whether the motor current reaches a preset locked-rotor current value I d If yes, the motor is powered off and the process goes to step 5). If no, the process repeats. In step 11), the driving mechanism (31) pushes the second smoke baffle (22) to move rightward and then determines whether the motor current reaches the preset stall current value I. d If yes, the motor is powered off and the process goes to step 5). If no, repeat this step.

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