A method for adjusting and controlling an oil fume and its filtering device of an extractor hood

Abstract

The present application relates to a kind of range hood and its filtering device adjusting control method, wherein the range hood includes the fume collecting hood (1) with air inlet, fan system being communicated with fume collecting hood (1), oil fume filtering device being arranged at the air inlet of fume collecting hood (1), oil fume filtering device includes fixedly arranged outer layer filter oil screen (3) and movably arranged inner layer filter oil screen (4), it is characterized in that: inner layer filter oil screen (4) includes left side inner layer filter oil screen (41) and right side inner layer filter oil screen (42), first oil fume concentration sensor and second oil fume concentration sensor are equipped at the left and right side position of outer layer filter oil screen front, and left side drive mechanism and right side drive mechanism;Left side drive mechanism and right side drive mechanism are set to: according to the oil fume concentration value collected by first oil fume concentration sensor and second oil fume concentration sensor, to adjust the gap between left side inner layer filter oil screen and right side inner layer filter oil screen and outer layer filter oil screen respectively.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of range hood oil fume and its filtering device adjustment control method. BACKGROUND

[0002] Generally, the household cooking stove is double eye, to ensure that the oil fume generated by two cooking stoves can be captured, the air inlet of the range hood on the market is mostly wide, to ensure that the oil fume generated by two cooking stoves can be sucked into the hood through the air inlet. But in actual use, the use frequency of left and right two cooking stoves is not the same and usually will not be used at the same time for operation such as stir-frying, for example, one cooking stove is used for frying, and the other cooking stove is usually used for boiling soup. The amount of oil fume generated on the left and right sides of the air inlet of the hood is often different. In order to ensure good smoke suction effect, the existing range hood usually sets a left and right rotating guide plate in the air duct of the range hood to realize the flow distribution of oil fume on the left and right sides of the hood. This way requires enough space in the air duct of the hood for the guide plate to turn over, and at the same time, the position of the guide plate cannot be too far from the air inlet, otherwise the flow distribution effect will disappear. There are also some technologies on the market that change the flow area of the oil screen by setting double-layer filter screens and moving between the double-layer filter screens to realize flow distribution. For example, CN202121635337.1 Chinese patent, its filter screen assembly includes a fixed filter screen, a first movable filter screen and a second movable filter screen, and the first movable filter screen is arranged on the left side of the second movable filter screen and realizes the misplacement of the oil screen through the cooperation of the gear and rack, thereby realizing flow distribution. The cooperation of the gear and rack needs to be driven by a motor, which not only occupies space and increases cost, but also is easy to cause problems such as jamming. Therefore, the existing technology needs to be further improved. SUMMARY

[0003] The first technical problem to be solved by the present application is to provide a range hood with an oil fume filtering device capable of realizing flow distribution on the left and right sides of the air inlet.

[0004] The second technical problem to be solved by the present application is to provide a filtering device adjustment control method for a range hood capable of realizing flow distribution on the left and right sides of the air inlet.

[0005] The present application solves the first technical problem by adopting the technical scheme of a range hood, comprising a smoke collecting hood with an air inlet, a fan system in communication with the smoke collecting hood, and an oil fume filtering device arranged at the air inlet of the smoke collecting hood, wherein the oil fume filtering device comprises an outer filter screen and an inner filter screen, the outer filter screen is a fixed filter screen, and the inner filter screen is a movable filter screen, and the inner filter screen can move relative to the outer filter screen to change the gap between the inner and outer filter screens, characterized in that the inner filter screen comprises a left inner filter screen and a right inner filter screen, the left inner filter screen and the right inner filter screen can move relative to the outer filter screen, respectively, a first oil fume concentration sensor is arranged at the left side of the front of the outer filter screen, a second oil fume concentration sensor is arranged at the right side of the front of the outer filter screen, the left inner filter screen is connected with a left driving mechanism for driving the left inner filter screen to move relative to the outer filter screen, and the right inner filter screen is connected with a right driving mechanism for driving the right inner filter screen to move relative to the outer filter screen; and the left driving mechanism and the right driving mechanism are arranged to adjust the gap between the left inner filter screen and the right inner filter screen and the outer filter screen, respectively, according to the oil fume concentration values collected by the first oil fume concentration sensor and the second oil fume concentration sensor.

[0006] As an improvement, the left driving mechanism comprises a bolt column fixedly connected at the back side of the outer filter screen, the left inner filter screen is movably connected to the bolt column and located between the left inner filter screen and the outer filter screen, a reset spring is arranged on the bolt column outside the left inner filter screen and the outer filter screen, the side opposite to the left inner filter screen and the outer filter screen is provided with an electromagnet or a metal capable of being attracted by the electromagnet, the corresponding position of the back side of the outer filter screen is also provided with a metal capable of being attracted by the electromagnet or an electromagnet, or the corresponding positions of the opposite sides of the left inner filter screen and the outer filter screen are both provided with electromagnets capable of being attracted to each other after being electrified, and the electromagnets are all connected to a power supply, the magnetic force of the electromagnets is adjusted by adjusting the current intensity connected to the electromagnets, so as to adjust the gap between the left inner filter screen and the outer filter screen.

[0007] As a further improvement, the right driving mechanism has the same structure and working principle as the left driving mechanism.

[0008] As a further improvement, the mesh holes of the outer filter screen and the inner filter screen are staggered.

[0009] As a further improvement, a third oil fume concentration sensor is arranged at the left side of the back of the inner filter screen, and a fourth oil fume concentration sensor is arranged at the right side of the back of the inner filter screen; and the left driving mechanism and the right driving mechanism are arranged to adjust the gap between the left inner filter screen and the right inner filter screen and the outer filter screen, respectively, according to the oil fume concentration values collected by the first oil fume concentration sensor, the second oil fume concentration sensor, the third oil fume concentration sensor, and the fourth oil fume concentration sensor.

[0010] The first technical solution adopted by the present invention to solve the second technical problem mentioned above is: a method for adjusting and controlling the filter device of a range hood having the above structure, characterized in that: after the range hood is started, the fan system first runs at a low speed, and is controlled through the following steps:

[0011] Step 1: Read the oil fume concentration K on the left and right sides in front of the oil fume filter device using the first oil fume concentration sensor and the second oil fume concentration sensor respectively. l and K r ;

[0012] Step 2, determine |K l -K r |Is it less than or equal to the preset value Kx? If yes, proceed to step 3; if no, proceed to step 8.

[0013] Step 3, let K t =(K l +K r ) / 2; Read the oil fume concentration K on the left and right sides at the next moment. l+1 and K r+1 Determine |K l+1 -K r+1 |Is it less than or equal to the set value Kx? If yes, proceed to step 4; if no, proceed to step 8.

[0014] Step 4, let K t+1 =(K l+1 +K r+1 ) / 2; Determine K t+1 Is it less than or equal to K? t If so, maintain the current fan speed, maintain the existing gap between the inner and outer oil filter screens on the left, and maintain the existing gap between the inner and outer oil filter screens on the right, then return to step 1; otherwise, proceed to step 5.

[0015] Step 5: Determine K t+1 Is it greater than or equal to the preset large oil fume concentration threshold K1? If yes, proceed to step 6; if no, increase the speed of the fan system, and at the same time reduce the gap between the left inner filter screen and the right inner filter screen and the outer filter screen (3), and then return to step 1.

[0016] Step 6: Determine K t+1 Is it greater than or equal to the preset ultra-high oil fume concentration threshold K2? If yes, proceed to step 7; if no, increase the speed of the fan system, and at the same time increase the gap between the left inner filter screen and the right inner filter screen and the outer filter screen, and then return to step 1.

[0017] Step 7, increase the gear of the fan system, and directly adjust the gap between the left inner filter screen and the outer filter screen and the gap between the right inner filter screen and the outer filter screen to the maximum value, and then return to step 1;

[0018] Step 8, if K l is less than K r , keep the gap between the left inner filter screen and the outer filter screen unchanged, and adjust the gap between the right inner filter screen and the outer filter screen to the maximum value; if K l is greater than K r , keep the gap between the right inner filter screen and the outer filter screen unchanged, and adjust the gap between the left inner filter screen and the outer filter screen to the maximum value.

[0019] The second technical solution adopted by the present application to solve the second technical problem is: a filter device adjustment control method of a range hood with the above structure, characterized in that: after the range hood is started, the fan system is first operated at a low gear, and the control is performed through the following steps:

[0020] Step 1, read the oil fume concentrations K l and K r on the left and right sides in front of the oil fume filtering device through the first oil fume concentration sensor and the second oil fume concentration sensor respectively;

[0021] Step 2, judge whether |K l -K r | is less than or equal to a preset value Kx, if yes, enter step 3; if |K l -K r | is greater than the preset value Kx and K l is less than K r , enter step 8; if the preset value Kx and K l is greater than K r , enter step 11;

[0022] Step 3, let K t =(K l +K r ) / 2; read the oil fume concentrations K l+1 and K r+1 on the left and right sides at the next time, judge whether |K l+1 -K r+1 | is less than or equal to the set value Kx, if yes, enter step 4; if |K l+1 -K r+1 | is greater than the set value Kx and K l+1 is less than K r+1 , enter step 8; if |K l+1 -K r+1 | is greater than the set value Kx and K l+1 is greater than Kr+1 Proceed to step 11;

[0023] Step 4, let K t+1 =(K l+1 +K r+1 ) / 2; Determine K t+1 Is it less than or equal to K? t If so, maintain the current fan speed, keep the existing gap between the inner and outer oil filter screens on the left unchanged, keep the existing gap between the inner and outer oil filter screens on the right unchanged, and then return to step 1; otherwise, proceed to step 5.

[0024] Step 5: Determine K t+1 Is it greater than or equal to the preset large oil fume concentration threshold K1? If yes, proceed to step 6; if no, increase the speed of the fan system, and at the same time reduce the gap between the left inner filter screen and the right inner filter screen and the outer filter screen, and then return to step 1.

[0025] Step 6: Determine K t+1 Is it greater than or equal to the preset ultra-high oil fume concentration threshold K2? If yes, proceed to step 7; if no, increase the speed of the fan system, and at the same time increase the gap between the left inner filter screen and the right inner filter screen and the outer filter screen, and then return to step 1.

[0026] Step 7: Increase the speed of the fan system, and at the same time, directly adjust the gap between the left inner oil filter and the right inner oil filter and the outer oil filter to the maximum value, and then return to step 1;

[0027] Step 8: Keep the gap between the inner and outer filter screens on the left unchanged, and adjust the gap between the inner and outer filter screens on the right to the maximum value; then proceed to step 9.

[0028] Step 9: Read the oil fume concentration K on the left and right sides behind the internal filter device of the range hood using the third and fourth oil fume concentration sensors. bl K br Then determine K l With K bl Is the difference greater than or equal to the first preset value K? sl Determine K r With K br Is the difference greater than or equal to the second preset value K? rl If K l -K bl ≥K sl Determine if the gap between the inner and outer oil filter screens on the left side has reached its maximum value. If so, increase the fan system speed and return to step 1; otherwise, increase the gap between the inner and outer oil filter screens on the left side until it reaches its maximum value, and then return to step 1. If Kl -K bl <K sl , enter step 10; if K r -K br ≥K rl , raise the fan system gear, and then return to step 1; if K r -K br <K rl , enter step 10;

[0029] Step 10, determine whether K l is greater than or equal to a preset large oil fume concentration threshold K1. If not, keep the gap between the left inner oil filter screen and the outer oil filter screen unchanged, keep the existing gap between the right inner oil filter screen and the outer oil filter screen unchanged, and keep the existing gear of the fan system, and then return to step 1. If yes, determine whether K r is less than or equal to a preset extra-large oil fume concentration threshold K2. If not, raise the fan system gear, and then return to step 1. If yes, determine whether the gap between the left inner oil filter screen and the outer oil filter screen reaches the maximum value. If yes, raise the fan system gear, and then return to step 1. If not, increase the gap between the left inner oil filter screen and the outer oil filter screen until the maximum value, and then return to step 1.

[0030] Step 11, keep the gap between the right inner oil filter screen and the outer oil filter screen unchanged, and adjust the gap between the left inner oil filter screen and the outer oil filter screen to the maximum value. Then enter step 12.

[0031] Step 12, read the oil fume concentrations K bl and K br on the left and right sides behind the oil fume filtering device inside the smoke machine through the third oil fume concentration sensor and the fourth oil fume concentration sensor, and then determine whether the difference between K l and K bl is greater than or equal to a first preset value K sl , and determine whether the difference between K r and K br is greater than or equal to a second preset value K rl . If K r -K br ≥K r1 , determine whether the gap between the right inner oil filter screen and the outer oil filter screen reaches the maximum value. If yes, raise the fan system gear, and then return to step 1. If not, increase the gap between the right inner oil filter screen and the outer oil filter screen until the maximum value, and then return to step 1. If K r -K br <K rl , enter step 13; if K l -K bl ≥K sl, increase the fan system gear, and then return to step 1; if K l -K bl <K sl , enter step 13;

[0032] Step 13, judge whether K r is greater than or equal to the preset large oil fume concentration threshold K1, if not, keep the gap between the right inner layer oil filter screen and the outer layer oil filter screen unchanged, keep the existing gap between the left inner layer oil filter screen and the outer layer oil filter screen unchanged, keep the existing gear of the fan system, and then return to step 1; if yes, judge whether K l is less than or equal to the preset extra large oil fume concentration threshold K2, if not, increase the fan system gear, and then return to step 1; if yes, judge whether the gap between the right inner layer oil filter screen and the outer layer oil filter screen reaches the maximum value, if yes, increase the fan system gear, and then return to step 1; if not, increase the gap between the right inner layer oil filter screen and the outer layer oil filter screen until the maximum value, and then return to step 1.

[0033] Compared with the prior art, the advantages of the present application are that: by forming the oil fume filtering device into a double-layer oil screen structure, and adjusting the gap between the left inner layer oil filter screen and the outer layer oil filter screen and the gap between the right inner layer oil filter screen and the outer layer oil filter screen according to the oil fume concentration values collected by the first oil fume concentration sensor and the second oil fume concentration sensor on the left and right sides in front of the oil fume filtering device, the flow distribution is adjusted according to the actual oil fume concentration situation, and the smoke suction effect and the oil fume filtering capacity are considered. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a three-dimensional structure schematic diagram of the extractor hood in the embodiment one of the present application.

[0035] Figure 2 It is a left side structure schematic diagram of the oil fume filtering device in the embodiment one of the present application.

[0036] Figure 3 It is an exploded view of the left side part of the oil fume filtering device in the embodiment one of the present application.

[0037] Figure 4 It is an exploded view of the left side part of the oil fume filtering device in the embodiment one of the present application from another perspective.

[0038] Figure 5 It is a position schematic diagram of the front and rear oil fume concentration sensors of the oil fume filtering device in the embodiment two of the present application. DETAILED DESCRIPTION

[0039] The present application will be further described in detail below in combination with the embodiment of the drawings.

[0040] Embodiment one

[0041] As Figure 1 shown in the oil fume extractor, comprising a body 2, the front side of the body 2 is provided with a smoke collecting hood 1 with an air inlet, the rear side of the body is internally provided with a fan system (not shown in the figure) communicated with the smoke collecting hood 1, an oil fume filtering device is arranged at the air inlet of the smoke collecting hood 1, the oil fume filtering device comprises an outer layer filter screen 3 and an inner layer filter screen 4, the mesh holes of the outer layer filter screen 3 and the inner layer filter screen 4 are staggered, the outer layer filter screen 3 is a fixed filter screen, the inner layer filter screen 4 is a movable filter screen, the inner layer filter screen 4 can move relative to the outer layer filter screen 3 to change the gap between the inner and outer layers of the filter screen.

[0042] The outer layer filter screen 3 can be a whole filter screen, in the embodiment, the outer layer filter screen 3 comprises two left and right outer layer filter screens 31 and 32 spliced together, the inner layer filter screen 4 comprises a left inner layer filter screen 41 and a right inner layer filter screen 42, the left and right inner layer filter screens 41 and 42 can move relative to the left and right outer layer filter screens 31 and 32 respectively.

[0043] The left side of the front of the outer layer filter screen 3 is provided with a first oil fume concentration sensor 5, the right side of the front of the outer layer filter screen 3 is provided with a second oil fume concentration sensor 6, the left inner layer filter screen 41 is connected with a left driving mechanism for driving the left inner layer filter screen 41 to move relative to the outer layer filter screen 3, the right inner layer filter screen 42 is connected with a right driving mechanism for driving the right inner layer filter screen 42 to move relative to the outer layer filter screen 3; the left and right driving mechanisms are arranged to adjust the gap between the left and right inner layer filter screens 41 and 42 and the outer layer filter screen 3 respectively according to the oil fume concentration values collected by the first and second oil fume concentration sensors 5 and 6.

[0044] The left outer layer filter screen 31, the left inner layer filter screen 41 and the left driving mechanism are described in detail in the description of the left outer layer filter screen 31. Figure 2 , 3As shown in Figure 4, the device includes a bolt post 9 fixedly connected to the rear side of the left outer oil filter screen 31, and a left inner oil filter screen 41 movably connected to the bolt post 9. A return spring 10 is fitted over the bolt post 9 located between the left inner oil filter screen 41 and the left outer oil filter screen 31. An inner electromagnet 11 is provided on the side of the left inner oil filter screen 41 opposite to the left outer oil filter screen 31, and an outer electromagnet 12, which can be attracted by the inner electromagnet, is provided at a corresponding position on the rear side of the left outer oil filter screen 31. Both the inner electromagnet 11 and the outer electromagnet 12 are connected to a power source. The magnetic strength of these electromagnets is adjusted by adjusting the current intensity connected to the inner electromagnet 11 and the outer electromagnet 12, thereby adjusting the gap between the left inner oil filter screen 41 and the left outer oil filter screen 31. The inner electromagnet 11 can be replaced by a metal that can be attracted by the outer electromagnet 12; or the outer electromagnet 12 can be replaced by a metal that can be attracted by the inner electromagnet 11. The right-side drive mechanism has the same structure and working principle as the left-side drive mechanism.

[0045] The adjustment and control method for the filter device of the above-mentioned range hood is as follows: After the range hood is started, the fan system first runs at a low speed and is controlled through the following steps:

[0046] Step 1: Read the oil fume concentration K on the left and right sides in front of the oil fume filter device using the first oil fume concentration sensor 5 and the second oil fume concentration sensor 6 respectively. l and K r ;

[0047] Step 2, determine |K l -K r |Is it less than or equal to the preset value Kx? If yes, proceed to step 3; if no, proceed to step 8.

[0048] Step 3, let K t =(K l +K r ) / 2; Read the oil fume concentration K on the left and right sides at the next moment. l+1 and K r+1 Determine |K l+1 -K r+1 |Is it less than or equal to the set value Kx? If yes, proceed to step 4; if no, proceed to step 8.

[0049] Step 4, let K t+1 =(K l+1 +K r+1 ) / 2; Determine K t+1 Is it less than or equal to K? t If so, maintain the existing fan speed, maintain the existing gap between the inner oil filter screen 41 on the left and the outer oil filter screen 3, maintain the existing gap between the inner oil filter screen 42 on the right and the outer oil filter screen 3, and then return to step 1; otherwise, proceed to step 5.

[0050] Step 5, judge K t+1 whether greater than or equal to a preset large oil fume concentration threshold K1, if yes, enter step 6; if no, increase the gear of the fan system, while synchronously reducing the gap between the left inner layer oil filter screen 41 and the right inner layer oil filter screen 42 and the outer layer oil filter screen 3, and then return to step 1;

[0051] Step 6, judge K t+1 whether greater than or equal to a preset large oil fume concentration threshold K2, if yes, enter step 7; if no, increase the gear of the fan system, while synchronously increasing the gap between the left inner layer oil filter screen 41 and the right inner layer oil filter screen 42 and the outer layer oil filter screen 3, and then return to step 1;

[0052] Step 7, increase the gear of the fan system, while directly adjusting the gap between the left inner layer oil filter screen 41 and the right inner layer oil filter screen 42 and the outer layer oil filter screen 3 to the maximum value, and then return to step 1;

[0053] Step 8, if K l is less than K r , keep the gap between the left inner layer oil filter screen 41 and the outer layer oil filter screen 3 unchanged, and adjust the gap between the right inner layer oil filter screen 42 and the outer layer oil filter screen 3 to the maximum value; if K l is greater than K r , keep the gap between the right inner layer oil filter screen 42 and the outer layer oil filter screen 3 unchanged, and adjust the gap between the left inner layer oil filter screen 41 and the outer layer oil filter screen 3 to the maximum value.

[0054] Example Two

[0055] Different from example one, a third oil fume concentration sensor 7 is arranged at the left rear position of the inner layer oil filter screen 4, and a fourth oil fume concentration sensor 8 is arranged at the right rear position of the inner layer oil filter screen 4, as shown in Figure 5 ; the left driving mechanism and the right driving mechanism are arranged to adjust the gap between the left inner layer oil filter screen 41 and the right inner layer oil filter screen 42 and the outer layer oil filter screen 3 according to the oil fume concentration values collected by the first oil fume concentration sensor 5, the second oil fume concentration sensor 6, the third oil fume concentration sensor 7 and the fourth oil fume concentration sensor 8.

[0056] In this embodiment, the adjustment and control method of the filtering device of the range hood is as follows: after the range hood is started, the fan system is first operated at a low gear, and is controlled through the following steps:

[0057] Step 1, read the oil fume concentrations K l and K r in front of the oil fume filtering device and on the left and right sides respectively through the first oil fume concentration sensor and the second oil fume concentration sensor;

[0058] Step 2, judge |K l -K r | is less than or equal to the preset value Kx, go to step 3; if |K l -K r | is greater than the preset value Kx, and K l is less than K r , go to step 8; if the preset value Kx and K l is greater than K r , go to step 11;

[0059] Step 3, let K t =(K l +K r ) / 2; read the next moment of the left and right oil smoke concentration K l+1 and K r+1 , judge |K l+1 -K r+1 | is less than or equal to the set value Kx, if yes, go to step 4; if |K l+1 -K r+1 | is greater than the set value Kx and K l+1 is less than K r+1 , go to step 8; if |K l+1 -K r+1 | is greater than the set value Kx and K l+1 is greater than K r+1 , go to step 11;

[0060] Step 4, let K t+1 =(K l+1 +K r+1 ) / 2; judge whether K t+1 is less than or equal to K t , if yes, keep the existing fan gear, keep the existing gap between the left inner filter oil screen 41 and the outer filter oil screen 3 unchanged, keep the existing gap between the right inner filter oil screen 42 and the outer filter oil screen 3 unchanged, and then return to step 1; if not, go to step 5;

[0061] Step 5, judge whether K t+1 is greater than or equal to the preset large oil smoke concentration threshold K1, if yes, go to step 6; if not, increase the gear of the fan system, and simultaneously reduce the gap between the left inner filter oil screen 41 and the right inner filter oil screen 42 and the outer filter oil screen (3), and then return to step 1;

[0062] Step 6, judge K t+1If yes, go to step 7; if no, increase the gear of the fan system, and simultaneously increase the gap between the left inner filter screen 41 and the outer filter screen 3 and the gap between the right inner filter screen 42 and the outer filter screen 3, and then return to step 1;

[0063] Step 7, increase the gear of the fan system, and directly adjust the gap between the left inner filter screen 41 and the outer filter screen 3 and the gap between the right inner filter screen 42 and the outer filter screen 3 to the maximum value, and then return to step 1;

[0064] Step 8, keep the gap between the left inner filter screen 41 and the outer filter screen 3 unchanged, and adjust the gap between the right inner filter screen 42 and the outer filter screen 3 to the maximum value, and then go to step 9;

[0065] Step 9, read the oil fume concentration K bl and K br on the left and right sides behind the oil fume filtering device in the range hood through the third oil fume concentration sensor and the fourth oil fume concentration sensor, and then determine whether the difference between K l and K bl is greater than or equal to the first preset value K sl , whether the difference between K r and K br is greater than or equal to the second preset value K rl , if K l -K bl ≥ K sl , determine whether the gap between the left inner filter screen 41 and the outer filter screen 3 reaches the maximum value, if yes, increase the gear of the fan system, and then return to step 1; if no, increase the gap between the left inner filter screen 41 and the outer filter screen 3 until the maximum value, and then return to step 1; if K l -K bl <K sl , go to step 10; if K r -K br ≥ K rl , increase the gear of the fan system, and then return to step 1; if K r -K br <K rl , go to step 10;

[0066] Step 10, determine whether K l is greater than or equal to the preset large oil fume concentration threshold K1, if no, keep the gap between the left inner filter screen 41 and the outer filter screen 3 unchanged, keep the existing gap between the right inner filter screen 42 and the outer filter screen 3 unchanged, and keep the existing gear of the fan system, and then return to step 1; if yes, determine whether K rIf no, increase the gap between the left inner filter screen 41 and the outer filter screen 3 until the maximum value, and then return to step 1; if yes, increase the fan system gear, and then return to step 1.

[0067] Step 11, keep the gap between the right inner filter screen 42 and the outer filter screen 3 unchanged, and adjust the gap between the left inner filter screen 41 and the outer filter screen 3 to the maximum value; then enter step 12.

[0068] Step 12, read the oil fume concentration K bl and K br on the left and right sides behind the oil fume filtering device in the range hood through the third oil fume concentration sensor and the fourth oil fume concentration sensor. l , judge whether the difference between K bl and K sl is greater than or equal to the first preset value K r , judge whether the difference between K br and K rl is greater than or equal to the second preset value K r , if K br -K r1 ≥ K r , judge whether the gap between the right inner filter screen 42 and the outer filter screen 3 reaches the maximum value, if yes, increase the fan system gear, and then return to step 1; if no, increase the gap between the right inner filter screen 42 and the outer filter screen 3 until the maximum value, and then return to step 1; if K br -K rl < K l , enter step 13; if K bl -K sl ≥ K l , increase the fan system gear, and then return to step 1; if K bl -K sl < K r , enter step 13.

[0069] Step 13, judge whether K lIf the concentration of the oil fume is less than or equal to the preset threshold K2, the fan system is raised to the next gear, and the process returns to step 1. If the concentration of the oil fume is greater than the preset threshold K2, it is determined whether the gap between the inner filter screen 42 and the outer filter screen 3 on the right side reaches the maximum value. If the gap reaches the maximum value, the fan system is raised to the next gear, and the process returns to step 1. If the gap does not reach the maximum value, the gap between the inner filter screen 42 and the outer filter screen 3 on the right side is increased until the maximum value is reached, and the process returns to step 1.

Claims

1. A range hood comprising a hood (1) having an air inlet, a fan system communicating with the hood (1), an oil fume filtering device arranged at the air inlet of the hood (1), said oil fume filtering device comprising an outer filter screen (3) and an inner filter screen (4), said outer filter screen (3) being a fixed filter screen, said inner filter screen (4) being a movable filter screen, said inner filter screen (4) being movable relative to the outer filter screen (3) to change the gap between the inner and outer filter screens, characterized in that: The inner layer oil filter screen (4) comprises a left inner layer oil filter screen (41) and a right inner layer oil filter screen (42), the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) can be moved relative to the outer layer oil filter screen (3), the outer layer oil filter screen (3) is provided with a first oil fume concentration sensor (5) at a left front position of the outer layer oil filter screen (3), the outer layer oil filter screen (3) is provided with a second oil fume concentration sensor (6) at a right front position of the outer layer oil filter screen (3), the left inner layer oil filter screen (41) is connected with a left driving mechanism for driving the left inner layer oil filter screen (41) to move relative to the outer layer oil filter screen (3), the right inner layer oil filter screen (42) is connected with a right driving mechanism for driving the right inner layer oil filter screen (42) to move relative to the outer layer oil filter screen (3); the left driving mechanism and the right driving mechanism are arranged to adjust the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) according to the oil fume concentration values collected by the first oil fume concentration sensor (5) and the second oil fume concentration sensor (6); the left driving mechanism comprises a bolt column (9) fixedly connected to the rear side of the outer layer oil filter screen (3), the left inner layer oil filter screen (41) is movably connected to the bolt column, a reset spring (10) is arranged on the bolt column between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3), the side opposite to the outer layer oil filter screen (3) of the left inner layer oil filter screen (41) is provided with an electromagnet or a metal capable of being attracted by the electromagnet, the rear side of the outer layer oil filter screen (3) is also provided with a metal capable of being attracted by the electromagnet or an electromagnet, or the side opposite to the outer layer oil filter screen (3) of the left inner layer oil filter screen (41) is provided with electromagnets capable of being attracted to each other after being electrified, the electromagnets are connected to a power supply, the magnetic force of the electromagnets is adjusted by adjusting the current intensity connected to the electromagnets, so as to adjust the gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3).

2. The hood according to claim 1, characterized in that: The right driving mechanism has the same structure and working principle as the left driving mechanism.

3. The hood according to claim 1, characterized in that: The mesh holes of the outer layer oil filter screen (3) and the inner layer oil filter screen (4) are staggered.

4. The hood according to claim 1, characterized in that: The rear left position of the inner layer oil filter screen (4) is provided with a third oil fume concentration sensor (7), and the rear right position of the inner layer oil filter screen (4) is provided with a fourth oil fume concentration sensor (8); the left driving mechanism and the right driving mechanism are arranged to adjust the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) according to the oil fume concentration values collected by the first oil fume concentration sensor (5), the second oil fume concentration sensor (6), the third oil fume concentration sensor (7) and the fourth oil fume concentration sensor (8).

5. The method of claim 1, wherein the method further comprises: determining a cooking activity of the cooktop; and adjusting the filter control based on the cooking activity. 5 After the oil fume extractor is started, the fan system is first operated at a low gear, and is controlled through the following steps: Step 1, read the oil fume concentration K of the left and right sides in front of the oil fume filtering device through the first oil fume concentration sensor and the second oil fume concentration sensor respectively l and K r ; Step 2, judge |K l -K r | is less than or equal to the preset value Kx, if yes, go to step 3, if no, go to step 8; Step 3, let K t = (K l + K r ) / 2; read the oil smoke concentration K l+1 and K r+1 on the left and right sides at the next moment, judge whether |K l+1 - K r+1 | is less than or equal to the set value Kx, if yes, go to Step 4, if no, go to Step 8; Step 4, let K t+1 = (K l+1 + K r+1 ) / 2; determine whether K t+1 is less than or equal to K t , if yes, keep the existing fan gear, keep the existing gap between the left inner filter screen (41) and the outer filter screen (3), keep the existing gap between the right inner filter screen (42) and the outer filter screen (3), and then return to step 1; if no, go to step 5; Step 5, judge K t+1 whether greater than or equal to a preset large oil fume concentration threshold K1, if yes, go to step 6; if no, increase the gear of the fan system, and simultaneously reduce the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3), and then return to step 1; Step 6, judge K t+1 whether greater than or equal to a preset extra oil fume concentration threshold K2, if yes, enter step 7; if no, increase the gear of the fan system, and simultaneously increase the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3), and then return to step 1. Step 7, increase the gear of the fan system, and directly adjust the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) to the maximum value, and then return to step 1. Step 8, if K l is less than K r , keep the gap between the left inner filter screen (41) and the outer filter screen (3) unchanged, and adjust the gap between the right inner filter screen (42) and the outer filter screen (3) to the maximum value; if K l is greater than K r , keep the gap between the right inner filter screen (42) and the outer filter screen (3) unchanged, and adjust the gap between the left inner filter screen (41) and the outer filter screen (3) to the maximum value.

6. A method of adjusting the filter of a range hood according to claim 1, characterized in that: After the range hood is started, the fan system first runs at a low gear, and is controlled through the following steps: Step 1, read the oil fume concentration K of the left and right sides in front of the oil fume filtering device through the first oil fume concentration sensor and the second oil fume concentration sensor respectively l and K r ; Step 2, judge |K l -K r | is less than or equal to a preset value Kx, go to step 3; if |K l -K r | is greater than the preset value Kx, and K l is less than K r , go to step 8; if the preset value Kx and K l is greater than K r , go to step 11; Step 3, let K t = (K l + K r ) / 2; read the oil smoke concentration K l+1 and K r+1 on the left and right sides at the next moment, judge whether |K l+1 -K r+1 | is less than or equal to the set value Kx, if yes, go to Step 4; if |K l+1 -K r+1 | is greater than the set value Kx and K l+1 is less than K r+1 , go to Step 8; if |K l+1 -K r+1 | is greater than the set value Kx and K l+1 is greater than K r+1 , go to Step 11; Step 4, let K t+1 = (K l+1 + K r+1 ) / 2; determine whether K t+1 is less than or equal to K t , if yes, keep the existing fan gear, keep the existing gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) unchanged, keep the existing gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) unchanged, and then return to step 1; if no, go to step 5; Step 5, judge K t+1 whether greater than or equal to a preset large oil fume concentration threshold K1, if yes, go to step 6; if no, increase the gear of the fan system, and simultaneously reduce the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3), and then return to step 1; Step 6, judge K t+1 whether greater than or equal to a preset extra oil fume concentration threshold K2, if yes, enter step 7; if no, increase the gear of the fan system, and simultaneously increase the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3), and then return to step 1. Step 7, increase the gear of the fan system, and directly adjust the gap between the left inner layer oil filter screen (41) and the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) to the maximum value, and then return to step 1; Step 8, keep the gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) unchanged, adjust the gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) to the maximum value; then enter step 9; Step 9, read the oil fume concentration K of the left and right sides behind the filtering device inside the smoke machine through the third and fourth oil fume concentration sensors bl , br Then determine whether the difference between K l and K bl is greater than or equal to the first preset value K sl Determine whether the difference between K r and K br is greater than or equal to the second preset value K rl If K l -K bl ≥ K sl Determine whether the gap between the left inner oil filter screen (41) and the outer oil filter screen (3) reaches the maximum value, if yes, then increase the fan system gear, and then return to step 1; if no, increase the gap between the left inner oil filter screen (41) and the outer oil filter screen (3) until the maximum value, and then return to step 1; if K l -K bl <K sl Go to step 10; if K r -K br ≥ K rl Increase the fan system gear, and then return to step 1; if K r -K br <K rl Go to step 10; Step 10, judge K l whether greater than or equal to a preset large oil fume concentration threshold K1, if not, keep the gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) unchanged, keep the existing gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) unchanged, keep the existing gear of the fan system, and then return to step 1; if yes, judge whether K r whether less than or equal to a preset extra large oil fume concentration threshold K2, if not, increase the gear of the fan system, and then return to step 1; if yes, judge whether the gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) reaches a maximum value, if yes, increase the gear of the fan system, and then return to step 1; if not, increase the gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) until the maximum value, and then return to step 1; Step 11, keep the gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) unchanged, adjust the gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) to the maximum value; then enter step 12; Step 12, read the oil fume concentration K of the left and right sides behind the filtering device inside the smoke machine through the third oil fume concentration sensor and the fourth oil fume concentration sensor bl , K br Then determine whether the difference between K l and K bl is greater than or equal to the first preset value K sl Determine whether the difference between K r and K br is greater than or equal to the second preset value K rl If K r -K br ≥ K r1 Determine whether the gap between the right inner oil filter screen (42) and the outer oil filter screen (3) reaches the maximum value, if yes, then increase the fan system gear, and then return to step 1; if no, increase the gap between the right inner oil filter screen (42) and the outer oil filter screen (3) until the maximum value, and then return to step 1; if K r -K br <K rl Go to step 13; if K l -K bl ≥ K sl Increase the fan system gear, and then return to step 1; if K l -K bl <K sl Go to step 13; Step 13, judge K r whether greater than or equal to a preset large oil fume concentration threshold K1, if not, keep the gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) unchanged, keep the existing gap between the left inner layer oil filter screen (41) and the outer layer oil filter screen (3) unchanged, keep the existing gear of the fan system, and then return to step 1; if yes, judge whether K l whether less than or equal to a preset extra large oil fume concentration threshold K2, if not, increase the gear of the fan system, and then return to step 1; if yes, judge whether the gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) reaches a maximum value, if yes, increase the gear of the fan system, and then return to step 1; if not, increase the gap between the right inner layer oil filter screen (42) and the outer layer oil filter screen (3) until the maximum value, and then return to step 1.

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