Lifting type range hood

Abstract

A lifting type range hood, a lower box body makes lifting movement relative to an upper box body, an air inlet body makes lifting movement relative to the lower box body, a fan is installed in the upper box body, the air inlet body has a smoke inlet, a middle axis L of a fan impeller passes through a vertical plane S, and the vertical plane S is perpendicular to a plane where the smoke inlet is located, a point of intersection of the vertical plane S and an upper edge of the smoke inlet is B, a point of intersection of the middle axis L of the fan impeller and a plane M where a volute cover plate located on a main air inlet side of the fan is located is A, in a state that the lower box body and the air inlet body are lifted to the highest position, an included angle between a line connecting the point A and the point B and a plumb plane is alpha, in a state that the lower box body and the air inlet body are lowered to the lowest position, an included angle between the line connecting the point A and the point B and the plumb plane is beta, and 0°≤|alpha-beta|≤15° is satisfied. The lifting type range hood limits two angle difference range values, so that the range hood has sufficient lowering stroke and negative pressure area moves downward to ensure oil fume suction effect, and has sufficient lifting stroke to ensure that the whole machine has small volume.

Description

Technical Field

[0001] This invention relates to the field of range hood technology, and in particular to a lift-type range hood. Background Technology

[0002] Range hoods have become an indispensable appliance in modern family kitchens. With their increasing usage, people are paying more and more attention to their smoke extraction efficiency and aesthetic appeal. Traditional top-mounted range hoods are bulky, making it easy for cooks to bump their heads. If the distance between the range hood's air inlet and the area where smoke is generated is large, the smoke's intake path is longer, increasing the extraction time and making it easier for smoke to escape during cooking. Lowering the installation height of the range hood and bringing the inlet as close to the smoke source as possible, while improving smoke extraction, results in a smaller cooking space, making it easier for the cook's head to accidentally hit the smoke hood. Furthermore, a lower installation height also affects visibility and the overall appearance of the kitchen. Therefore, lift-type range hoods were invented, where the smoke inlet can be raised and lowered; it lowers when the hood is on and rises when it is off. For example, the range hood disclosed in Chinese utility model patent No. 202222918682.7 (authorization announcement No. CN 218864291 U) includes a smoke collection chamber, a fan assembly and a lifting assembly. The fan assembly is set inside the smoke collection chamber, and the lifting assembly is connected to the smoke collection chamber. The lifting assembly can drive the smoke collection chamber to rise and fall. When the range hood is running, the lifting component lowers the smoke collection chamber below the cabinet, and the fan starts to extract the fumes. When the range hood is not running, the lifting component raises the smoke collection chamber into the cabinet, and the fan stops. This range hood has a single-stage lifting structure, with only one lifting component for the smoke collection chamber. The structure is relatively simple, and the positional constraints are relatively limited. For a range hood with a two-stage lifting structure, it is necessary to consider that each lifting component has sufficient downward travel to significantly lower the negative pressure zone and improve the smoke extraction effect. It is also necessary to consider that when each lifting component is raised, the overall height of the unit should be reduced to make the range hood more compact and concise, allowing for concealed installation. Therefore, the positional constraints between multiple different lifting components need to be considered. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a liftable range hood that has a good oil fume extraction effect in the working state and a low overall height in the non-working state, in view of the above-mentioned existing technology.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a lifting range hood, comprising an upper housing, a lower housing, and an air inlet, wherein the lower housing is disposed on the upper housing and can move up and down relative to the upper housing, the air inlet is disposed on the lower housing and can move up and down relative to the lower housing, a fan is installed in the upper housing, and the air inlet has a smoke inlet, characterized in that:

[0005] The impeller's central axis L of the fan lies within a vertical plane S, which is perpendicular to the horizontal plane and also perpendicular to the plane where the smoke inlet is located. The intersection point of the vertical plane S and the upper edge of the smoke inlet is B. The intersection point of the impeller's central axis L and the plane M containing the volute cover plate located on the side of the fan's main air inlet is A.

[0006] The upper and lower housings are connected by a drive mechanism. The drive mechanism allows the lower housing to move up and down relative to the upper housing, reaching either a maximum or minimum position. Similarly, the air inlet and the lower or upper housing are also connected by a drive mechanism, allowing the air inlet to move up and down relative to the upper housing, reaching either a maximum or minimum position. When both the lower housing and the air inlet are at their maximum positions, the angle between the line connecting point A to point B and the plumb line is α, and there is a vertical gap between the lowest position of the fan and the main body of the air inlet. When both the lower housing and the air inlet are at their minimum positions, the angle between the line connecting point A to point B and the plumb line is β, satisfying 0°≤|α-β|≤15°. When points A and B lie on the same vertical line, the included angles α and β are both 0°, and |α-β| is also 0. In some embodiments, 0°≤|α-β|≤b, where b is 10° or 5°.

[0007] The line connecting points A and B can form an angle with the plumb line or be parallel to it. Point A is the center point of the fan inlet, and point B is the initial inlet where cooking fumes enter the range hood. The fumes are drawn into the range hood through the inlet, pass through the flow channel, enter the fan inlet, and are then expelled. Therefore, the smaller the distance between points A and B in the front-to-back direction, the better the direct suction and exhaust effect. A zero angle represents the ideal state for direct suction and exhaust. Furthermore, a larger angle is more conducive to direct suction and exhaust. Since point B only moves vertically, a larger angle indicates a greater vertical distance between points A and B, allowing the negative pressure zone of the range hood to be lowered further, enabling the fumes to be drawn into the inlet the moment they are generated. In this design, when the fan is not in operation, both the lower housing and the air inlet can be raised. After the lower housing is raised, the upper housing can be stored inside the lower housing, and the air inlet can also be stored inside the lower housing after being raised. Therefore, when raised, the air inlet and the upper housing can be hidden in the lower housing, which is more aesthetically pleasing and reduces the overall size of the unit, allowing for more kitchen space. The smaller the α value, the closer points A and B are, and therefore the smaller the overall size of the unit. However, the α value also needs an upper limit to ensure that points A and B maintain a certain distance in the vertical direction. That is, to ensure that the fan and the air intake body maintain a certain interval in the vertical direction, and the air intake body must always be located below the fan. This setting ensures that the oil in the fan can be guided from top to bottom into the air intake body, and then into the oil cup at the bottom of the air intake body. Therefore, when the lower box and the air intake body rise to the highest position, there is a gap in the vertical direction between the lowest position of the fan and the main body of the air intake body. That is, the main body of the air intake body is always located below the fan, so that the oil in the fan can be guided into the air intake body along the natural downward trend, and then discharged from the inner cavity of the range hood. This avoids the accumulation of oil in the fan or dripping into other places when the range hood is not in use, which cannot be discharged in time. At this time, the air intake body also acts as an oil guiding channel. In both the raised and lowered states, the greater the difference between the angle between the line connecting points A and B and the plumb plane, the greater the travel of the lower casing and the air intake, thus better achieving the effect of reducing the negative pressure zone and minimizing the size of the range hood when it is raised. Therefore, only when |α-β|≥0° can the range hood be guaranteed to have the function of direct suction and exhaust and reducing the negative pressure zone when it is lowered, while having the effect of reducing the overall size and guiding oil smoothly when it is raised.

[0008] Considering that the installation height of the fan and the distance to the stove are limited, the travel before and after the change in lifting state should not be too large. Therefore, it is limited here that |α-β|≤15°.

[0009] The angle between the line connecting points A and B and the plumb line needs to have a lower limit. Only when the angle exceeds this lower limit can we ensure that the air intake body is neither too wide in the front-to-back direction, which would cause the pot to be blocked, nor too narrow in the front-to-back direction, which would cause the air intake channel to be too narrow and affect the oil fume extraction effect.

[0010] Preferably, the lower housing is equipped with an oil guide plate, which has a horizontally arranged oil guiding section located within the gap, and can guide the oil dripping from the fan into the air intake body. With this configuration, the main body of the air intake body is always located below the fan, allowing the oil inside the fan to fall naturally into the air intake body and then be discharged from the inner cavity of the range hood. This prevents oil from accumulating inside the fan or dripping and accumulating in other locations when the range hood is not in use, thus avoiding the accumulation of oil in the fan or dripping oil that cannot be discharged in time. In this case, the air intake body also acts as an oil guiding channel.

[0011] Further preferably, the oil guide plate also has a mounting part that is detachably connected to or integrally formed with the oil guide portion, and the mounting part is mounted on the lower housing.

[0012] Further preferably, the lowest point formed by the intersection of the vertical plane S and the front cover plate of the volute is point E, the vertical projection of this point onto the oil guide is point E', the intersection of the rear edge of the oil guide plate and the vertical plane S is point F, and the line connecting points E' and F gradually slopes downwards from front to back. This design, with its inclination, facilitates the flow of oil from high to low, allowing the oil to enter the air intake body.

[0013] Further optimization involves setting the angle between the line connecting points E' and F and the horizontal plane to be a°, and the length of the vertical projection of the line connecting points E' and F onto the horizontal plane to be L1. With the lower housing (2) and the air inlet (3) raised to their highest positions, the overall height of the machine is L2, satisfying: 0.005*L2≤L1*tan a°≤0.16*L2. This design ensures that, while the gap exists, it provides sufficient space to accommodate the oil guide plate, and the gap height is relatively small compared to the overall machine height, preventing excessive increases in overall machine height when both the lower housing and the air inlet are raised to their highest positions, thus maintaining structural compactness.

[0014] Further preferably, when the lower housing is raised to its highest position, the upper housing is at least partially housed within the lower housing, and when the air inlet is raised to its highest position, the air inlet is at least partially retracted within the lower housing. When the lower housing and air inlet are both raised to their highest positions, the angle α between the line connecting point A and point B and the plumb line satisfies 0 ≤ α ≤ c. The value of c can be 30°, 25°, 20°, 15°, or 10°; preferably, c is 15°. This setting limits the upper limit of the angle α, thus limiting the maximum rising stroke of the lower housing and air inlet, preventing excessive rising and interference with the fan.

[0015] Further preferably, when the lower housing is lowered to its lowest position, the bottom end of the upper housing and the top end of the lower housing are connected. When both the lower housing and the air inlet are at their lowest positions, the angle β between the line connecting point A and point B and the plumb line surface satisfies 0 ≤ β ≤ d. The value of d can be 25°, 20°, 15°, 10°, or 5°; preferably, the value of d is 10°. This setting, by defining the maximum value of the angle β, limits the minimum descent stroke of the lower housing and the air inlet, ensuring that the negative pressure zone can move sufficiently downward to improve the fume extraction effect.

[0016] Further optimization yields a value of 0.5 < tanα / tanβ ≤ 0.8. In the direction perpendicular to the horizontal plane, tanα / tanβ is the ratio of the distance from point A to point B when both the lower casing and the air inlet are at their highest positions to the distance when both are at their lowest positions. This ratio represents the height change of the entire range hood in both the raised and lowered states. Within this range, the negative pressure zone of the range hood can be reduced during fume extraction, achieving the same effect as the overall size of the unit when not in use.

[0017] With both the lower housing and the air inlet body raised to their highest positions, the horizontal plane containing the top edge of the front panel of the lower housing is N. The fan is at least partially located within the lower housing, and the vertical distance h between point A and horizontal plane N satisfies: h ≤ 120mm. This upper limit on h ensures that the center point of the fan is as close to the lower housing as possible, allowing the lower housing to at least partially enclose the fan and reducing the overall size of the unit. At this point, point A can be located either above or below horizontal plane N.

[0018] Further optimized, with both the lower housing and the air inlet body raised to their highest positions, point A is located inside the lower housing. Thus, more than half of the fan is located vertically within the lower housing, reducing space occupancy. The oil cup is located at the bottom of the air inlet body, shortening the path from the fan to the oil cup and reducing the oil flow, preventing oil from splashing inside the housing due to its high dripping distance.

[0019] The main air inlet of the fan is located at the rear of the fan, the top of the air inlet body is open, and the smoke inlet is located on the front of the air inlet body. In this way, after the fumes are drawn in through the smoke inlet, they can flow smoothly through the top opening of the air inlet body to the rear air inlet of the fan.

[0020] Further preferably, the main air inlet of the fan is the rear air inlet of the fan, the top of the air inlet body is open, and the smoke inlet is located on the front of the air inlet body. In this way, after the oil fumes are drawn in through the smoke inlet, they can flow smoothly through the top opening of the air inlet body to the rear air inlet of the fan.

[0021] Further optimization involves ensuring that the projection of point B along the vertical direction coincides with the projection of point A along the vertical direction. This guarantees direct suction and discharge, and makes oil guiding smoother.

[0022] Further optimized, the projection of point B along the vertical direction onto plane N is B′, and the projection of point A along the vertical direction onto plane N is A′. The vertical distance from point B′ to the top edge of the front panel of the lower housing is less than the vertical distance from point A′ to the top edge of the front panel of the lower housing. With this configuration, the air inlet is necessarily located below the fan when the housing is raised, which facilitates the diversion of oil from the fan into the air inlet and then into the oil cup.

[0023] Further optimized, a fourth air intake channel is formed between the rear air inlet of the fan and the back panel of the upper casing, and a first air intake channel is formed within the air intake body. The depth of the first air intake channel is greater than the depth of the fourth air intake channel. This configuration ensures direct suction and exhaust, and facilitates smoother oil drainage. Taking the front panel and back panel of the lower casing of the range hood as an example, the front panel is located at the front, and the back panel is located at the rear. The depth of the air intake channel refers to the width of the air intake channel in the front-to-back direction.

[0024] To further ensure the direct suction and discharge effect, the projection of the first air intake channel along the vertical direction on plane N overlaps with the projection of the fourth air intake channel along the vertical direction on plane N, and the overlapping area exceeds 80% of the projection area of ​​the first air intake channel along the vertical direction on plane N.

[0025] In order to allow for sufficient positional clearance between the fan and the air inlet body during the lifting process, avoid positional interference, and ensure smooth oil flow, a gap exists in the vertical direction between the fan and the main body of the air inlet body when the lower housing and the air inlet body are raised to their highest positions.

[0026] Further preferably, the height h1 of the gap satisfies: 0 < h1 ≤ 80 mm. Setting the gap within this range ensures both smooth oil flow and a relatively small overall size.

[0027] As a preferred embodiment of any of the above solutions, an air inlet channel is formed within the lower housing, and the smoke inlet is fluidly connected to the fan inlet through the air inlet channel. In this way, after the fumes are drawn in through the smoke inlet, they can be smoothly drawn into the fan through the air inlet channel.

[0028] Further preferably, the lower housing includes a second air inlet channel and a third air inlet channel that are interconnected. The top of the third air inlet channel is open and fluidly connected to the upper housing. The bottom of the third air inlet channel forms an opening near the back panel of the lower housing, and this opening extends downward to form the second air inlet channel. The second air inlet channel is fluidly connected to the air intake body and the third air inlet channel. This configuration results in an air intake chamber that is wide at the top and narrow at the bottom. The narrow second air inlet channel facilitates rapid intake of cooking fumes, improving the fume extraction effect, while the wide third air inlet channel acts as a pressure stabilizing chamber, reducing fume escape and lowering noise.

[0029] Further optimized, with the lower housing at its lowest position, the fan is positioned entirely above the third air inlet channel, and the air inlet extends downwards from the bottom of the lower housing. With the lower housing raised to its highest position, the fan extends at least partially into the third air inlet channel, and the air inlet portion of the air inlet extends at least partially into the second air inlet channel. This configuration allows the lower housing's air inlet channel to accelerate airflow and stabilize pressure and reduce noise during fume extraction, while accommodating the air inlet and fan respectively in the raised position, thus reducing space occupancy.

[0030] Further optimized, the width W2 of the third air inlet channel in the front-to-back direction and the width W1 of the second air inlet channel in the front-to-back direction satisfy: W2 ≥ 1.5W1. With this configuration, the structures of the third and second air inlet channels form a variable cross-section air inlet channel, which can effectively block the direct transmission of noise from the fan system. By simulating the principle of reactive noise cancellation, the sound waves emitted from the fan are reflected multiple times within the wide upper cavity and thus canceled out. Therefore, a variable cross-section acoustic impedance is constructed, reducing the energy of sound propagating from the fan inlet to the range hood inlet. Additionally, constructing this airflow buffer cavity, simulating a static pressure box, can improve the unsteady flow separation caused by inlet distortion, thereby reducing pressure pulsation and improving sound quality.

[0031] Furthermore, the fan also has a front air inlet. This creates a dual-inlet structure, facilitating the smoother entry of oil fumes from the pressure stabilizing chamber into the fan's interior.

[0032] Further optimized, with the lower housing and air inlet at their lowest positions, the air inlet is entirely exposed below the lower housing. This maximizes the negative pressure zone and optimizes fume extraction.

[0033] Further optimized, with the lower housing and air inlet body raised to their highest positions, the air inlet is entirely concealed inside the lower housing. This design prevents backflow of cooking fumes and insects from entering the range hood through the fume inlet.

[0034] Further preferably, with the lower housing and air inlet body raised, at least a portion of the bottom of the fan and at least a portion of the air inlet body are inserted into the lower housing. This configuration reduces the overall height of the unit, facilitating concealed installation.

[0035] Compared with the prior art, the advantages of this invention are as follows: This liftable range hood adopts a dual-stage lifting structure in which both the lower housing and the air inlet can be lifted. Since the position of the fan remains unchanged, the angle between the line connecting point A to point B and the plumb line changes during the lifting process of the lower housing and the air inlet. By limiting the range of the angle difference between the two states of the highest and lowest positions, the lifting stroke of the lower housing and the air inlet can be limited within a certain range. This ensures that the range hood has sufficient downward stroke to ensure the negative pressure zone moves down to ensure effective smoke extraction, and sufficient upward stroke to ensure a small overall size, making it easy to hide the entire unit in the kitchen cabinets for a high aesthetic appeal. The upper limit of the angle difference also ensures that the vertical deviation between the smoke inlet of the surface air inlet and the air inlet of the fan is not too large, ensuring a direct suction and exhaust effect. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the structure of a range hood according to an embodiment of the present invention (in a non-working state);

[0037] Figure 2 for Figure 1 The image shows a front view of the range hood.

[0038] Figure 3 for Figure 2 The image shows a sectional view of the range hood along the DD direction;

[0039] Figure 4 for Figure 2 The DD section view of the range hood shown;

[0040] Figure 5 for Figure 4 A magnified view of a portion of the image;

[0041] Figure 6 This is a schematic diagram of the air inlet body according to an embodiment of the present invention;

[0042] Figure 7 A schematic diagram of the structure of a range hood according to an embodiment of the invention (in working condition);

[0043] Figure 8 for Figure 7 The image shows a front view of the range hood.

[0044] Figure 9 for Figure 7 A three-dimensional sectional view of the range hood shown;

[0045] Figure 10 for Figure 8 The image shows a cross-sectional view of the range hood along the EE direction. Detailed Implementation

[0046] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0047] It should be noted that all solutions in this application are implemented in the installation state of the range hood, which is that the range hood is installed along a vertical plane that is perpendicular to the horizontal plane, that is, the back panel is parallel to the vertical plane.

[0048] like Figures 1 to 10 As shown, the lift-type range hood of this embodiment includes an upper housing 1, a lower housing 2, and an air inlet 3. The lower housing 2 is mounted on the upper housing 1 and can move up and down relative to the upper housing 1, while the air inlet 3 is mounted on the lower housing 2 and can move up and down relative to the lower housing 2, thus realizing a two-stage lifting structure. The lower housing 2 and the air inlet 3 can move synchronously under the drive of a single drive mechanism, or they can move independently under the drive of separate drive mechanisms.

[0049] The top of the air inlet 3 is open, and the front of the air inlet 3 has a smoke inlet 31. The smoke inlet 31 can be perpendicular to the horizontal plane or tilted at a certain angle relative to the horizontal plane. A fan 4 is installed inside the upper casing 1. The smoke inlet 31 is connected to the air inlet of the fan 4 through the air intake channel inside the range hood. Oil fumes are drawn in through the smoke inlet 31, enter the air intake channel through the top opening, and are then discharged outward by the fan 4. When the lower casing 2 and the air inlet 3 are raised, at least part of the bottom of the fan 4 enters the lower casing 2, and at least part of the air inlet 3 enters the lower casing 2. Figures 1 to 3 As shown, with the lower housing 2 and the air inlet 3 raised to their highest positions, the smoke inlet 31 is entirely concealed inside the lower housing 2. Figures 7 to 10 As shown, with the lower housing 2 and the air inlet 3 lowered to their lowest positions, the smoke inlet 31 is entirely exposed below the lower housing 2. Figure 6 As shown, the air inlet 3 of this embodiment includes a main body 32 and vertical extensions 33 located on both sides of the main body 32 and extending upward. A smoke inlet 31 is formed on the main body 32. A guide rail 9 is installed between the vertical extension 33 and the lower housing back plate 22. The air inlet 3 can move up and down relative to the lower housing 2 along the guide rail 9.

[0050] by Figure 3 The direction indicated by the middle arrow C is backward. In this embodiment, the fan 4 is a vertically arranged centrifugal fan. The fan 4 adopts a front and rear air intake structure, that is, the fan 4 has a rear air intake 41 and a front air intake 42. Among them, the rear air intake 41 is the main air intake, and the front air intake 42 is the auxiliary air intake. Here, "vertical" is not limited to being perpendicular to the horizontal plane, but can also be at a certain angle relative to the vertical direction.

[0051] like Figure 9 As shown, a vertical plane S is defined. The impeller centerline L of the fan 4 lies within the vertical plane S. The vertical plane S is perpendicular to the horizontal plane and also perpendicular to the plane where the smoke inlet 31 is located. This vertical plane S is... Figure 8 The plane containing the cross-section along the EE direction is consistent with the plane containing the cross-section. For example... Figure 3 and Figure 10 As shown, the intersection point B between the vertical plane S and the upper edge of the smoke inlet 31 is the same as the intersection point A between the impeller central axis L and the plane M containing the volute cover plate 43 located on the side of the main air inlet of the fan. Here, the upper edge of the smoke inlet 31 refers to the lower edge of the upper guide plate 7 above the smoke inlet 31. Figure 3 As shown, when the lower housing 2 and the air inlet 3 are raised to their highest positions, the angle between the line connecting point A and point B and the plumb plane is α. When the lower housing 2 and the air inlet 3 are lowered to their lowest positions, the angle between the line connecting point A and point B and the plumb plane is β, satisfying 0°≤|α-β|≤15°. The plumb plane refers to a vertical plane perpendicular to the horizontal plane. In the installed state of the range hood, the back panel 11 of the upper housing, the back panel 22 of the lower housing, and the back panel of the air inlet 3 are all parallel to the plumb plane.

[0052] In some embodiments, 0°≤|α-β|≤b, where b is 10° or 5°.

[0053] By limiting the range of the angle difference between the two states of rising to the highest position and falling to the lowest position, the lifting stroke of the lower housing 2 and the air inlet 3 can be limited within a certain range. This ensures that the range hood has sufficient downward stroke to ensure effective smoke extraction by shifting the negative pressure zone downward, and sufficient upward stroke to ensure a small overall size, making it easy to hide the entire unit in the kitchen cabinets for a high aesthetic appeal. The upper limit of the angle difference indicates that the vertical deviation between the smoke inlet 21 of the air inlet 3 and the fan inlet will not be too large, ensuring a direct suction and exhaust effect.

[0054] The upper housing 1 is connected to the lower housing 2 via a drive mechanism, and the air inlet 3 is connected to the upper housing 1 via a drive mechanism, or the air inlet 3 is connected to the lower housing 2 via a drive mechanism. A fan 4 is installed inside the upper housing 1. When the lower housing 2 and the air inlet 3 are both raised to their highest positions under the action of the drive mechanism, the upper housing 1 and the air inlet 3 are both located inside the lower housing 2. At this time, there is a gap d between the horizontal plane at the lowest point of the fan 4 and the horizontal plane at the highest point of the air inlet 3. That is, in the vertical direction, there is a gap d between the bottom of the fan 4 and the air inlet body 32. In this way, the air inlet body 32 is always located below the fan 4, so that the oil in the fan 4 can be guided into the air inlet 3 along the natural downward trend, and then discharged from the inner cavity of the range hood. This avoids the accumulation of oil in the fan 4 or dripping into other places when the range hood is not in use, which would prevent the oil from being discharged in time. At this time, the air inlet 3 also acts as an oil guiding channel.

[0055] like Figure 4 and Figure 5 As shown, the lower housing 2 is equipped with an oil guide plate 8, which has a horizontally arranged oil guide section 81 located within the gap d. The oil guide section 81 guides the oil dripping from the fan 4 into the air intake 3. The oil guide plate 8 also has a mounting section 82 that is detachably connected to or integrally formed with the oil guide section. The mounting section 82 is mounted on the lower housing 2. The lowest point formed by the intersection of the vertical plane S and the front cover plate 44 of the volute is point E. The vertical projection of this point onto the oil guide section is point E'. The point where the rear edge of the oil guide plate intersects with the vertical plane S is point F. The line connecting points E' and F gradually slopes downward from front to back to ensure that the oil can flow down the slope. The angle between the line connecting points E' and F and the horizontal plane is a°. The length of the vertical projection of the line connecting points E' and F on the horizontal plane is L1. When the lower housing 2 and the air inlet 3 are raised to their highest positions, the overall height of the machine is L2, which satisfies: 0.005*L2≤L1*tan a°≤0.16*L2. This setting ensures that, while the gap exists, there is enough space to accommodate the oil guide plate 8, and the height of the gap is relatively small compared to the overall height of the machine, so that the overall height of the machine will not increase too much when the lower housing 2 and the air inlet 3 are both raised to their highest positions, thus ensuring the compactness of the structure.

[0056] The volute of the fan 4 includes a front cover plate 44, a rear cover plate 43, and an annular wall 45. The aforementioned front cover plate 44 is the cover plate near the front panel 12 of the fan frame when the range hood is installed. The aforementioned overall height refers to the distance between the horizontal plane of the lowest point of the bottom of the range hood and the horizontal plane of the top plate 13 of the fan frame when the lower box 2 and the air inlet 3 are raised to their highest positions.

[0057] With the lower housing 2 raised to its highest position, the upper housing 1 is at least partially retracted within the lower housing 2. With the air inlet 3 raised to its highest position, the air inlet 3 is at least partially retracted within the lower housing 2. When both the lower housing 2 and the air inlet 3 are raised to their highest positions, the angle α between the line connecting point A and point B and the plumb line satisfies 0 ≤ α ≤ c, where c can be 30°, 25°, 20°, 15°, or 10°. Preferably, c is 15°. Setting an upper limit for the angle α here limits the maximum upward stroke of the lower housing 2 and the air inlet 3, preventing interference between the lower housing 2 and the fan 4 during the upward movement.

[0058] With the lower housing 2 at its lowest position, the bottom of the upper housing 1 and the top of the lower housing 2 are connected. When the lower housing 2 and the air inlet 3 are at their lowest positions, the angle β between the line connecting point A and point B and the plumb line surface satisfies 0 ≤ β ≤ d, where d can be 25°, 20°, 15°, 10°, or 5°, preferably 10°. In this state, setting an upper limit for the angle β ensures that the vertical deviation between the main air inlet and the smoke inlet 31 of the fan is not too large, achieving a direct suction and exhaust effect. An angle of 0° is the ideal state.

[0059] As a special case, the projection of point B along the vertical direction coincides with the projection of point A along the vertical direction. In this case, a direct exhaust and suction effect is formed inside the range hood, which not only has a good effect on absorbing oil fumes, but also facilitates oil drainage.

[0060] In addition, the ratio of tanα / tanβ must also satisfy the following range: 0.5 < tanα / tanβ ≤ 0.8. A larger tanα / tanβ ratio indicates a larger height difference between the lowered and raised states, satisfying the requirement of a low negative pressure zone in the lowered state and a small overall height dimension in the raised state.

[0061] like Figure 3As shown, the horizontal plane where the top edge of the front panel 21 of the lower housing 2 is located is defined as horizontal plane N. With the lower housing 2 and the air inlet 3 raised to their highest positions, the fan 4 is at least partially located inside the lower housing 2. Horizontal plane N is located above the impeller's central axis L, and point A is located inside the lower housing 2. Thus, more than half of the fan 4 is located within the lower housing in the vertical direction, reducing space occupation. The oil cup 6 is located at the bottom of the air inlet 3, reducing the path from the fan 4 to the oil cup 5, resulting in a shorter oil path and preventing oil from splashing inside the housing due to its high dripping stroke. Furthermore, the vertical distance h between point A and horizontal plane N satisfies: h ≤ 120mm. Setting the upper limit of h here ensures that the center point of the fan 4 is as close as possible to the lower housing 2, ensuring that the lower housing 2 at least partially encloses the fan 4, reducing the overall size of the unit. In addition, when the lower housing 2 and the air inlet 3 are raised to their highest positions, there is a gap between the fan 4 and the air inlet 3. The height h1 of this gap satisfies the condition: 0 < h1 ≤ 80 mm. Setting the gap within this range ensures both smooth oil flow and a small overall size.

[0062] like Figure 3 As shown, the projection of point B along the vertical direction onto plane N is B′, and the projection of point A along the vertical direction onto plane N is A′. The vertical distance from point B′ to the top edge of the front panel 21 of the lower housing 2 is less than the vertical distance from point A′ to the top edge of the front panel 21 of the lower housing 2, meaning B′ is located in front of A′. With this configuration, when raised, the air inlet 3 will inevitably be located below the fan 4, which facilitates the dilution of oil in the fan 4 into the air inlet 4, and then into the oil cup 6 at the bottom of the air inlet 4.

[0063] In this embodiment, a first air intake channel 51 is formed within the air intake body 3, and a fourth air intake channel 54 is formed between the rear air intake 41 of the fan 4 and the back plate 11 of the upper housing. The depth of the first air intake channel 51 is greater than the depth of the fourth air intake channel 54. Here, depth refers to the front-to-back width of the channel. The greater depth of the first air intake channel 51 than the fourth air intake channel 54 ensures direct suction and exhaust, and makes oil guiding smoother. Furthermore, the projection of the first air intake channel 51 along the vertical direction onto plane N overlaps with the projection of the fourth air intake channel 54 along the vertical direction onto plane N, and the overlapping area exceeds 80% of the projection area of ​​the first air intake channel 51 along the vertical direction onto plane N. This further ensures direct suction and exhaust, and improves the oil fume extraction effect.

[0064] The lower housing 2 in this embodiment includes a front panel 21, a left side panel (not shown), a right side panel (not shown), and a lower housing back panel 22. The lower housing 2 internally forms a second air inlet channel 52 and a third air inlet channel 53. The smoke inlet 31 is fluidly connected to the fan inlet through the second air inlet channel 52 and the third air inlet channel 53. Specifically, the top of the third air inlet channel 53 is open and fluidly connected to the upper housing 1. The bottom of the third air inlet channel 53 forms an opening near the lower housing back panel 22, which extends downwards to form the second air inlet channel 52. The second air inlet channel 52 is fluidly connected to the air inlet body 3 and the third air inlet channel 53. With this configuration, the air inlet channels inside the lower housing 2 are wide at the top and narrow at the bottom. The narrow second air inlet channel 52 facilitates rapid smoke intake, improving the smoke extraction effect, while the wide third air inlet channel 53 acts as a pressure stabilizing chamber, reducing smoke escape and lowering noise. In this embodiment, the width W2 of the third air inlet channel 53 in the front-to-back direction and the width W1 of the second air inlet channel 52 in the front-to-back direction satisfy: W2 ≥ 1.5W1. Thus, the structures of the third air inlet channel 53 and the second air inlet channel 52 constitute a variable cross-section air inlet channel, which can effectively block the direct transmission of noise generated by the fan 4 to the outside. By simulating the principle of reactive noise cancellation, the sound waves emitted from the fan 4 are reflected multiple times inside the wide upper cavity and thus canceled out. Therefore, a variable cross-section acoustic impedance is constructed to reduce the energy of sound propagating from the fan inlet to the range hood inlet. In addition, the airflow buffer cavity is constructed to simulate a static pressure box, which can improve the unsteady flow separation caused by inlet distortion, thereby reducing pressure pulsation and improving sound quality.

[0065] In addition, such as Figure 3 As shown, when the lower housing 2 is lowered to its lowest position, the fan 4 is located above the third air inlet channel 53, and the air inlet body 3 extends downward to the bottom of the lower housing 2. When the lower housing 2 is raised to its highest position, the fan 4 extends at least partially into the third air inlet channel 53, and the air inlet part of the air inlet body 3 extends at least partially into the second air inlet channel 52. Thus, the air inlet channel of the lower housing 2 has the functions of accelerating the flow rate and stabilizing the pressure and reducing noise when the oil fume is being sucked up, and accommodates the air inlet body and the fan respectively when the housing is raised, thus reducing the space occupied.

[0066] In this embodiment, in addition to using a vertically arranged centrifugal fan, the fan 4 can also be a horizontally arranged centrifugal fan, that is, the central axis of the impeller of the fan is a vertical line perpendicular to the horizontal plane. This fan installation method is usually applied to ceiling-mounted range hoods.

[0067] The specification and claims of this invention use directional terms such as "front," "rear," "upper," "lower," "left," "right," "side," "top," and "bottom" to describe various exemplary structural parts and elements of the invention. However, these terms are used herein merely for ease of explanation and are determined based on the exemplary orientations shown in the accompanying drawings. Since the embodiments disclosed in this invention can be arranged in different orientations, these directional terms are for illustrative purposes only and should not be considered as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. Furthermore, in this embodiment, the definition and description of the structural state of the range hood refer to the range hood in its installed state.

[0068] The term "fluid connectivity" as used in this invention refers to the spatial relationship between two components or parts, collectively referred to as the first part and the second part, meaning that a fluid, gas, liquid, or a mixture of both can flow from the first part along a flow path and / or be transported to the second part. This can be a direct connection between the first part and the second part, or an indirect connection between the first part and the second part through at least one third party. This third party can be a fluid channel such as a pipe, channel, conduit, guide, hole, or groove, or a chamber that allows fluid to flow through, or a combination of the above.

Claims

1. A liftable range hood, comprising an upper housing (1), a lower housing (2), and an air inlet (3), wherein the lower housing (2) is disposed on the upper housing (1) and can move up and down relative to the upper housing (1), the air inlet (3) is disposed on the lower housing (2) and can move up and down relative to the lower housing (2), a fan (4) is installed inside the upper housing (1), and the air inlet (3) has a smoke inlet (31), characterized in that: The impeller central axis L of the fan (4) is located in the vertical plane S, and the vertical plane S is perpendicular to the plane where the smoke inlet (31) is located. The intersection point of the vertical plane S and the upper edge of the smoke inlet (31) is B, and the intersection point of the impeller central axis L and the plane M where the volute cover plate (43) located on the side of the main air inlet of the fan is A. When the lower housing (2) and the air inlet (3) are raised to their highest positions, the angle between the line connecting point A to point B and the plumb plane is α. There is a gap (d) between the horizontal plane where the lowest end of the fan (4) is located and the horizontal plane where the highest position of the main body of the air inlet (3) is located. When the lower housing (2) and the air inlet (3) are lowered to their lowest positions, the angle between the line connecting point A to point B and the plumb plane is β, which satisfies 0°≤|α-β|≤15°.

2. The lifting type range hood according to claim 1, characterized in that: 0°≤|α-β|≤b, where b is 5°~10°.

3. The lifting range hood according to claim 1, characterized in that: The lower housing (2) is provided with an oil guide plate (8), which has a horizontally arranged oil guide part (81). The oil guide part (81) is located in the gap (d) and can guide the oil dripping from the fan (4) into the air intake body (3).

4. The lifting range hood according to claim 3, characterized in that: The oil guide plate (8) also has a mounting part (82) that is detachably connected to or integrally formed with the oil guide part (81), and the mounting part (82) is mounted on the lower housing (2).

5. The lifting range hood according to claim 3, characterized in that: The lowest point formed by the intersection of the vertical plane S with the front cover plate (44) of the volute is point E. The vertical projection of this point on the oil guide is point E'. The intersection of the rear edge of the oil guide plate (8) with the vertical plane S is point F. The line connecting point E' and point F gradually slopes downward from front to back.

6. The lifting range hood according to claim 4, characterized in that: The angle between the line connecting points E' and F and the horizontal plane is a°. The length of the vertical projection of the line connecting points E' and F on the horizontal plane is L1. When the lower box (2) and the air inlet (3) are raised to the highest position, the height of the whole machine is L2, which satisfies: 0.005*L2≤L1*tan a°≤0.16*L2.

7. The lifting range hood according to claim 1, characterized in that: The height h1 of the gap (d) satisfies: 0 < h1 ≤ 80 mm.

8. The lifting range hood according to claim 1, characterized in that: When the lower housing (2) is raised to its highest position, the upper housing (1) is at least partially housed within the lower housing (2). When the air intake (3) is raised to its highest position, the air intake (3) is at least partially retracted within the lower housing (2). When the lower housing (2) and the air intake (3) are raised to their highest positions, the angle α between the line connecting point A to point B and the plumb line is satisfied that 0 ≤ α ≤ 15°.

9. The lifting range hood according to claim 1, characterized in that: When the lower box (2) is lowered to its lowest position, the bottom of the upper box (1) and the top of the lower box (2) are connected. When the lower box (2) and the air inlet (3) are lowered to their lowest positions, the angle β between the line connecting point A to point B and the plumb line is satisfied that 0 ≤ β ≤ 10°.

10. The lifting range hood according to claim 1, characterized in that: 0.5 < tanα / tanβ ≤ 0.

8.

11. The lifting range hood according to claim 8, characterized in that: When the lower housing (2) and the air inlet (3) are raised to their highest positions, the top edge of the front panel (21) of the lower housing (2) is located on the horizontal plane N, the fan (4) is located at least partially inside the lower housing (2), and the vertical distance h between point A and the horizontal plane N satisfies: h≤120mm.

12. The lifting range hood according to claim 11, characterized in that: With the lower housing (2) and the air inlet (3) raised to their highest positions, point A is located inside the lower housing (2).

13. The lifting range hood according to claim 11, characterized in that: The main air inlet of the fan is the rear air inlet (41) of the fan (4), the top of the air inlet body (3) is open, and the smoke inlet (31) is located on the front of the air inlet body (3).

14. The lifting range hood according to claim 13, characterized in that: The projection of point B along the vertical direction coincides with the projection of point A along the vertical direction.

15. The lifting range hood according to claim 13, characterized in that: The projection of point B along the vertical direction onto plane N is B′, and the projection of point A along the vertical direction onto plane N is A′. The vertical distance from point B′ to the top edge of the front panel (21) of the lower box (2) is less than the vertical distance from point A′ to the top edge of the front panel (21) of the lower box (2).

16. The lifting range hood according to claim 15, characterized in that: A fourth air intake channel (54) is formed between the rear air inlet (41) of the fan (4) and the back plate (11) of the upper box. A first air intake channel (51) is formed inside the air intake body (3). The depth of the first air intake channel (51) is greater than the depth of the fourth air intake channel (54).

17. The lifting range hood according to claim 16, characterized in that: The projection of the first air inlet channel (51) in the vertical direction onto plane N overlaps with the projection of the fourth air inlet channel (54) in the vertical direction onto plane N, and the overlapping area exceeds 80% of the projection area of ​​the first air inlet channel (51) in the vertical direction onto plane N.

18. The lifting range hood according to claim 11, characterized in that: When the lower housing (2) and the air inlet (3) are raised to their highest positions, there is a gap in the vertical direction between the fan (4) and the main body (32) of the air inlet.

19. The lifting range hood according to claim 18, characterized in that: The height h1 of the gap satisfies: 0 < h1 ≤ 80 mm.

20. The lifting range hood according to any one of claims 1 to 19, characterized in that: An air inlet channel is formed inside the lower housing (2), and the smoke inlet (31) is in fluid communication with the air inlet of the fan (4) through the air inlet channel.

21. The lifting range hood according to claim 20, characterized in that: The lower housing (2) includes a second air inlet channel (52) and a third air inlet channel (53) that are interconnected. The top of the third air inlet channel (53) is open and fluidly connected to the upper housing (1). The bottom of the third air inlet channel (53) forms an opening near the back plate (22) of the lower housing. The opening extends downward to form the second air inlet channel (52). The second air inlet channel (52) is fluidly connected to the air inlet body (3) and the third air inlet channel (53).

22. The lifting range hood according to claim 21, characterized in that: When the lower housing (2) is lowered to its lowest position, the fan (4) is located above the third air inlet channel (53), and the air inlet body (3) extends downward to the bottom of the lower housing (2). When the lower housing (2) is raised to its highest position, the fan (4) extends at least partially into the third air inlet channel (53), and the air inlet part of the air inlet body (3) extends at least partially into the second air inlet channel (52).

23. The lifting range hood according to claim 21, characterized in that: The width W2 of the third air intake channel (53) in the front-to-back direction and the width W1 of the second air intake channel (52) in the front-to-back direction satisfy: W2≥1.5W1.

24. The lifting range hood according to claim 13, characterized in that: The fan (4) also has a front air inlet (42).

25. The lifting range hood according to claim 1, characterized in that: With the lower housing (2) and the air inlet (3) lowered to their lowest positions, the smoke inlet (31) is fully exposed below the lower housing (2).

26. The lifting range hood according to claim 1, characterized in that: With the lower housing (2) and the air inlet (3) raised to their highest positions, the smoke inlet (31) is completely hidden inside the lower housing (2).

27. The lifting range hood according to claim 1, characterized in that: With the lower housing (2) and the air inlet (3) raised, the bottom of the fan (4) is at least partially inside the lower housing (2), and the air inlet (3) is at least partially inside the lower housing (2).

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