Lifting type range hood

Abstract

The application discloses a lifting type range hood, which comprises an upper box, a lower box and an air inlet body, the lower box is arranged on the upper box, and the air inlet body is arranged on the lower box, wherein a fan is arranged in the upper box, the range hood has at least two states, in a first state, the top end of the lower box is connected with the bottom end of the upper box, the air inlet body extends from the bottom of the lower box and is lowered to the lowest position, and in a second state, the lower box is lifted to the highest position so that the fan is at least partially located in the lower box, and the air inlet body is at least partially located in the lower box and is lifted to the highest position. The lifting type range hood has the advantages that in the first state, the air inlet body has a large lowering stroke, the negative pressure area is lowered to the lowest position, the oil fume suction effect is improved, in the second state, the fan is at least partially located in the lower box, the air inlet body is at least partially located in the lower box and is lifted to the highest position, the whole machine has a small size, a simple and compact structure, is convenient for oil guiding, is beneficial to hiding the whole machine in a kitchen cabinet and has high aesthetic degree.

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 located inside the smoke collection chamber, and the lifting assembly is connected to the smoke collection chamber, enabling the smoke collection chamber to rise and fall. When the range hood is running, the lifting assembly lowers the smoke collection chamber below the cabinet, and the fan assembly starts to extract the fumes. When the range hood is not running, the lifting assembly raises the smoke collection chamber into the cabinet, and the fan assembly turns off. This range hood discloses a single-stage lifting structure, with only one lifting assembly for the smoke collection chamber. The structure is relatively simple, and the positional constraints that need to be considered are relatively limited. For a range hood with a two-stage lifting structure, in order to achieve the goal of a large descent stroke and a small volume when raised, the positional constraints between multiple different lifting assemblies need to be considered.

[0003] In existing single-stage lifting range hoods, the air inlet is still relatively far from the smoke source, and the negative pressure zone is located high, resulting in poor smoke extraction. In contrast, existing dual-stage lifting range hoods still have a separate fan that occupies a significant amount of space, and during the lifting process, grease from the inner wall of the fan housing adheres to the outer wall of the lower housing, causing grease to drip onto the cooktop.

[0004] After the negative pressure zone of a dual-stage lifting range hood is lowered, the air inlet is closer to the smoke source. As soon as the fumes are generated, they are instantly sucked into the range hood, causing a large accumulation of fumes inside the cavity. Furthermore, the rapid flow of fumes drawn in from the narrow inlet creates turbulence and blockage within the cavity, hindering the effective absorption and removal of the fumes. On the other hand, the range hood's fan generates significant noise and vibrates considerably when turned on. Summary of the Invention

[0005] 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 when the machine is on and a small overall size when the machine is off, in view of the above-mentioned existing technology.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: the lifting range hood includes an upper box, a lower box, and an air inlet, wherein the lower box is disposed on the upper box and the air inlet is disposed on the lower box. The upper box contains a fan, and the range hood has at least two states. In the first state, the top of the lower box is connected to the bottom of the upper box, and the air inlet extends out from the bottom of the lower box and descends to its lowest position. In the second state, the lower box is raised to its highest position, such that at least part of the fan is located within the lower box, and at least part of the air inlet is located within the lower box and raised to its highest position.

[0007] The aforementioned lift-up range hood has multiple lifting states. The lower housing can be raised and lowered relative to the upper housing, allowing the upper housing to be at least partially housed within the lower housing. The air intake can extend outside the lower housing or be raised and retracted inside. During the transition from the second state to the first state, the range hood changes from a raised state to a lowered state. In the second state, both the lower housing and the air intake are raised to their highest possible positions. In the first state, both the lower housing and the air intake are lowered to their lowest possible positions.

[0008] In this solution, the negative pressure area of the whole machine is reduced through double-stage lifting. After the air inlet drops, a side oil fume suction path is formed and the descending air inlet body is ultra-thin, so it will not affect cooking operations at all. That is, in the first state, the position of the negative pressure area is just conducive to oil fume suction and the height will not block the pot. Wrapping the fan with the lower box can make the oil stain flow from the upper box to the inside of the lower box along the trend. In any state, the outer surface of the lower box is always on the outermost of the whole machine, so the outer surface of the lower box will not be polluted by oil stains, and there is no need for excessive oil circuit design between the upper box and the lower box. The front panel of the lower box can be set as a whole large panel, making the appearance simple and beautiful. The lower box wraps the fan and the air inlet body. After the oil fume passes through the air inlet body, it enters the lower box. The design of the lower box is not limited by the size of the fan box body, so there is enough space for design to make the lower box accumulate more oil fume and the flow channel can be optimized. On the other hand, by wrapping the fan box with the lower box, the noise of the fan enters the accommodation cavity of the lower box after passing out of the fan frame, simulating a static pressure box, improving the unsteady flow separation caused by the distortion of the air inlet, thereby reducing the pressure pulsation, improving the sound quality, and the noise can also be抵消 in the accommodation cavity using the principle of resistance sound absorption. The fan vibration is transmitted to the lower box, and the contact area between the lower box and the wall increases, reducing the vibration frequency of the whole machine.

[0009] To make the volume of the whole machine small enough in the shutdown state and facilitate the smooth downward export of the oil fluid of the fan system, the height of the upper box is L1, the height of the lower box is L2, and the height of the main body part of the air inlet body is L3. In the second state, the distance H2 between the fan air outlet and the bottom of the lower box satisfies L1 + L3 < H2 ≤ aL2, and 1 < a ≤ 1.8.

[0010] To make the volume of the whole machine small enough in the shutdown state and facilitate the smooth downward export of the oil fluid of the fan system, the height of the upper box is L1, the height of the lower box is L2, and the height of the main body part of the air inlet body is L3. In the second state, the distance H3 between the fan air outlet and the bottom of the air inlet body satisfies L1 + L3 < H3, and the distance H2 between the fan air outlet and the bottom of the lower box satisfies H2 ≤ aL2, and 1 < a ≤ 1.8.

[0011] The air inlet body is formed by enclosing a front plate, a rear plate, a left side plate, a right side plate and a bottom plate. An air inlet is provided on the front plate of the air inlet body, and the oil fume passes through the channel at the top of the air inlet body from the air inlet and is fluidly connected to the lower box. The height of the main body part of the air inlet body refers to the vertical distance between the horizontal plane where the highest position of the top edge of the front plate is located and the horizontal plane where the lowest position of the bottom plate is located.

[0012] Under the constraints of the above relationship, both the fan and the air inlet can be concealed within the upper casing, and they do not overlap or directly contact each other in the horizontal direction. The fan and the air inlet are arranged at intervals in the vertical direction. In the second state, the oil sludge from the fan system can be smoothly guided into the air inlet and then into the oil cup at the bottom of the air inlet. H2≤aL2. By limiting the upper limit of a, the lower casing needs to have sufficient height, thus ensuring a large descent stroke during lifting. The bottom surface of the lower casing and the side of the air inlet form a negative pressure area for smoke collection. Therefore, the negative pressure area of ​​the entire unit can be lowered to the position closest to the smoke source.

[0013] Preferably, in the second state, there is a gap between the horizontal plane of the lowest point of the fan and the horizontal plane of the highest point of the air inlet body. This ensures that the fan system and the air inlet body do not overlap or directly contact each other, allowing the oil in the fan system to be smoothly guided from top to bottom into the oil cup at the bottom of the air inlet body when the fan is off.

[0014] To ensure that the gap does not affect the overall height of the machine in the second state, the height h1 of the gap satisfies: 0 < h1 ≤ 80 mm. This setting ensures that oil flows smoothly from the fan into the air inlet and then into the oil cup, while saving space occupied by the machine.

[0015] To ensure the lower housing has a sufficiently large travel range and can accommodate the fan in the second state, the percentage of the overlap between the lower and upper housings in the vertical direction is limited in the off state to the height of the upper housing. In the second state, the fan and the lower housing overlap in the vertical direction, and the height of the overlap portion accounts for 40% to 80% of the height of the upper housing. This design fully utilizes the internal space of the lower housing. Furthermore, the cavity in the lower housing used to accommodate the fan has a larger volume, allowing the rapidly drawn-in fumes to be stabilized and flowed smoothly within this cavity during fume extraction, resulting in more efficient fume discharge.

[0016] To ensure that the air inlet is closer to the smoke source when the machine is in the fume extraction state, thereby reducing the negative pressure area of ​​the whole machine, in the first state, the height of the air inlet extending downward from the bottom of the lower box is h2, and the descent stroke of the lower box from the second state to the first state is h3. The relationship between h2 and h3 is: 0.3≤h2 / h3≤1.

[0017] To ensure sufficient downward travel of the entire unit during fume extraction, the overall height of the unit is limited in the first state. In the first state, the distance H1 between the fan outlet and the bottom of the air inlet satisfies the following condition: 0.75≤H1 / (L1+L2+L3)<1. This setting brings the negative pressure area closer to the smoke source, thereby improving the fume extraction effect.

[0018] To ensure that the overall size of the machine is small enough in the non-fume extraction state, the overall height of the machine in the second state is limited. In the second state, the distance H2 between the fan outlet and the bottom of the lower box satisfies the following condition with respect to L1, L2, and L3: 0.5≤H2 / (L1+L2+L3)≤0.8. This setting saves more space.

[0019] Further preferably, during any time period during the lifting and lowering process of the lower housing and the air inlet, the displacement of the lower housing relative to the upper housing is greater than the displacement of the air inlet relative to the lower housing. Thus, the lifting and lowering speed of the air inlet is less than the lifting and lowering speed of the lower housing.

[0020] Further preferably, the lower housing includes a first air inlet channel and a second air inlet channel that are interconnected. The first air inlet channel is located below and behind the second air inlet channel. In other states besides the first state, the air inlet body is at least partially located in the first air inlet channel, and the fan is at least partially located in the second air inlet channel.

[0021] Further optimized, the width W2 of the second air inlet channel in the front-to-back direction satisfies the same condition as the width W1 of the first air inlet channel in the front-to-back direction: W2 ≥ 1.5W1. With this configuration, the second air inlet channel forms a highly efficient pressure-stabilizing chamber. The narrower width of the first air inlet channel results in a faster flow velocity, allowing the fumes to be quickly drawn into the second air inlet channel. Within this pressure-stabilizing chamber, the fumes are buffered and stabilized, ensuring smooth exhaust. This also guarantees a relatively uniform airflow velocity at the smoke inlet, preventing smoke from escaping from both sides of the range hood.

[0022] In a further preferred embodiment, the upper housing also includes a fan frame. The fan can be a dual-inlet or rear-inlet fan. A third air inlet channel is provided between the rear air inlet of the fan and the rear plate of the fan frame. The width W1 of the first air inlet channel in the front-to-back direction is greater than the width W3 of the third air inlet channel in the front-to-back direction. With this configuration, the oil in the third air inlet channel can drip into the first air inlet channel and then flow into the oil cup at the bottom.

[0023] To facilitate oil collection, an oil cup is installed at the bottom of the air inlet body. In the second state, the oil cup extends at least partially into the lower housing.

[0024] In a further preferred embodiment, the oil cup extends completely into the lower housing, such that the bottom of the oil cup is flush with or higher than the bottom of the lower housing. This results in a compact and simple structure for the range hood when not in use, allowing it to be completely concealed within a cabinet during installation, enhancing its aesthetic appeal.

[0025] Further optimization reveals that, in the first state, the distance H1 between the fan outlet and the bottom of the inlet body satisfies: H1-H2≥250mm, H1-H2-L3≥150mm. This further limits the minimum descent stroke of the entire unit and the minimum descent stroke of the lower casing, ensuring that the negative pressure zone can descend a sufficient distance, thereby effectively improving the fume extraction effect.

[0026] In order to drive the lower housing and the air inlet to move up and down, the lower housing moves up and down relative to the upper housing under the drive of the drive mechanism, and the air inlet moves up and down relative to the lower housing under the drive of the drive mechanism.

[0027] Compared with the prior art, the advantages of the present invention are as follows: the lifting range hood has at least two states. In the first state, the top of the lower box is connected to the bottom of the upper box, the air inlet extends out of the bottom of the lower box and descends to the lowest position, the air inlet has a large descent stroke, the negative pressure zone moves to the lowest position, and the smoke extraction effect is improved. In the second state, the lower box is raised to the highest position so that the fan in the upper box is at least partially located in the lower box, and the air inlet is at least partially located in the lower box and raised to the highest position. The whole machine is small in size, simple and compact in structure, easy to guide oil, and can be hidden in the kitchen cabinet, which is aesthetically pleasing and saves external kitchen space. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of a range hood according to an embodiment of the present invention (in the first state);

[0029] Figure 2 for Figure 1 The diagram shows a cross-sectional view of the range hood.

[0030] Figure 3 This is a schematic diagram of the structure of a range hood according to an embodiment of the present invention (in the second state);

[0031] Figure 4 for Figure 3 The diagram shows a cross-sectional view of the range hood.

[0032] Figure 5 for Figure 4 The diagram shows the structure of the range hood after the lower back panel has been removed. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0034] like Figures 1 to 5As shown, the lift-type range hood of this embodiment includes an upper housing 1, a lower housing 2, and an air inlet 3. The upper housing 1 houses a fan frame 5, and a fan 4 is installed inside the fan frame 5. The fan 4 is a vertically arranged centrifugal fan with a front air inlet channel and a rear air inlet channel. The lower housing 2 is mounted on the upper housing 1 and can move up and down relative to the upper housing 1; the lower housing 2 also covers the exterior of the upper housing. Figure 4 The direction indicated by the middle arrow A is the rear side. The air inlet 3 is located at the lower rear part of the lower housing 2 and can move up and down relative to the lower housing 2. An oil cup 9 is installed at the bottom of the air inlet 3. In this embodiment, the air inlet 3 includes a main body 31 and vertical extensions 32 located on both sides of the main body 31 and extending upward. A smoke inlet 30 is formed on the main body 31. A guide rail 10 is installed between the vertical extensions 32 and the back plate 21 of the lower housing. The air inlet 3 can move up and down relative to the lower housing 2 along the guide rail 10.

[0035] 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. During any time period during the lifting and lowering process of the lower housing 2 and the air inlet 3, the displacement of the lower housing 2 relative to the upper housing 1 is greater than the displacement of the air inlet 3 relative to the lower housing 2, that is, the lifting and lowering speed of the lower housing 2 relative to the upper housing 1 is greater than the lifting and lowering speed of the air inlet 3 relative to the lower housing 2.

[0036] Driven by the drive mechanism, this lift-type range hood has at least two states: a first state and a second state. In the first state, as shown... Figure 3 and Figure 4 As shown, the top of the lower housing 2 connects to the bottom of the upper housing 1. The air inlet 3 extends from the bottom of the lower housing 2 and descends to its lowest position. The lowest position refers to the position where the air inlet reaches its maximum descent stroke; that is, the first state is the state with the maximum descent stroke, corresponding to the high air volume condition. In the second state, as shown... Figure 1 and Figure 2 As shown, when the lower housing 2 is raised to its highest position, the fan 4 is at least partially located inside the lower housing 2, and the air inlet 3 is also at least partially located inside the lower housing 2 and raised to its highest position. The highest position refers to the position where the air inlet 3 reaches its maximum upward stroke, i.e., the second state is the state with the maximum upward stroke, which is usually the off state. In addition, depending on the intensity of the oil fume, the range hood also has other intermediate states besides the first and second states. In these other intermediate states, the downward stroke of the lower housing 2 and the air inlet 3 is moderate.

[0037] In this embodiment, the lower housing 2 includes a first air inlet channel 6 and a second air inlet channel 7 that are fluidly connected to each other. The first air inlet channel 6 is located below and behind the second air inlet channel 7, and the width W2 of the second air inlet channel 7 in the front-to-back direction and the width W1 of the first air inlet channel 6 in the front-to-back direction satisfy: W2 ≥ 1.5W1. In this way, the second air inlet channel 7 forms a highly efficient pressure-stabilizing chamber. The first air inlet channel 6 is relatively narrow and has a faster flow velocity, so that the fumes can be quickly drawn into the second air inlet channel. The fumes can be buffered and stabilized in the pressure-stabilizing chamber, and the exhaust is smoother. At the same time, it also ensures that the smoke inlet 30 of the air intake body 3 has a basically the same wind speed, avoiding the problem of smoke escaping from both sides of the range hood. In addition, sound-absorbing cotton can be arranged in the pressure-stabilizing chamber for noise reduction. The noise inside the fan 4 can be better confined in the pressure-stabilizing chamber, realizing semi-isolation of the noise source from the user. The sound waves are reflected multiple times in this large cavity, which can improve the noise reduction effect of the sound-absorbing cotton.

[0038] The fan 4 can adopt a dual air inlet or a rear air inlet. In this embodiment, a third air inlet channel 8, i.e., a rear air inlet channel, is formed between the rear air inlet of the fan 4 and the rear plate of the fan frame 5. The third air inlet channel 8 is fluidly connected with the first air inlet channel 6 and the second air inlet channel 7. Furthermore, the width W1 of the first air inlet channel 6 in the front-to-back direction is greater than the width W3 of the third air inlet channel 8 in the front-to-back direction. This allows the oil in the third air inlet channel 8 to drip into the first air inlet channel 6 and then flow into the oil cup 9 at the bottom of the air intake body 3. In the first state, the fan 4 is located above the second air inlet channel 7, the main body 31 of the air intake body 3 is located below the first air inlet channel 6, and the vertical extension 32 of the air intake body 3 forms the left and right side walls of the first air inlet channel 6. In this embodiment, in the second state, the lower part of the fan 4 is located in the second air inlet channel 7, the air intake body 3 is completely hidden in the first air inlet channel 6, and the oil cup 9 is completely inserted into the lower housing 2 so that the bottom of the oil cup 9 is flush with the bottom of the lower housing 2. Furthermore, in the second state, the lower part of the air inlet 3 can also extend below the lower housing 2, and correspondingly, the oil cup 9 is also fully exposed. Alternatively, the bottom of the air inlet 3 is flush with the bottom of the lower housing 2 and the oil cup 9 is exposed. Or, the air inlet 3 extends entirely into the lower housing 2, but the upper part of the oil cup 9 extends into the lower housing and the lower part is exposed outside the lower housing 2. Typically, in the intermediate state between the first and second states, the air inlet 3 is at least partially located within the first air inlet channel 6, and the fan 4 is at least partially located within the second air inlet channel 7.

[0039] Let the height of the upper box body 1 be L1, the height of the lower box body 2 be L2, and the height of the main body 31 of the air inlet body 3 be L3. In the second state, the distance H2 between the air outlet of the fan 4 and the bottommost part of the lower box body 2 satisfies L1 + L3 < H2 ≤ aL2, and 1 < a ≤ 1.8. Alternatively, in the second state, the distance H3 between the air outlet of the fan 4 and the bottommost part of the air inlet body 3 satisfies L1 + L3 < H3, and H2 ≤ aL2, and 1 < a ≤ 1.8. If the height of the oil cup 9 is ignored, then H2 = H3. In addition, it must also be satisfied that: L3 < L2, such that the lower box body 2 is conducive to completely accommodating the air inlet body 3 in the height space, and the lower box body 2 still has extra height space to accommodate other structures in the height direction. L1 + L3 < H2 indicates that the fan 4 and the air inlet body 3 do not overlap and are not in direct contact, and the fan 4 is located above the air inlet body 3 in the height direction, which is conducive to smoothly guiding the oil liquid in the fan 4 from top to bottom into the oil cup 9 at the bottom end of the air inlet body 3 in the second state. H2 ≤ aL2 (1 < a ≤ 1.8) limits the size of the whole machine, avoiding the whole machine being too large in the second state and saving kitchen space.

[0040] In the second state, the range hood of this embodiment also satisfies the following position constraint relationship: there is a gap h1 between the horizontal plane where the lowermost end of the fan 4 is located and the horizontal plane where the highest position of the main body of the air inlet body 3 is located, and 0 < h1 ≤ 80 mm, so as to ensure that the oil stain flows down from the fan into the air inlet body 3 and then into the oil cup 9, while saving the space occupied by the whole machine. The fan 4 and the lower box body 2 have an overlapping part in the vertical direction, and the height of the overlapping part accounts for 40% - 80% of the height of the upper box body 1, so as to make full use of the internal space of the lower box body 2 and ensure that the lower box body 2 has a sufficient large movement stroke and can accommodate the fan 4 in the second state. On the other hand, it also shows that the cavity volume of the lower box body for accommodating the fan is relatively large. In the state of sucking oil fume, the quickly sucked oil fume can be stabilized in pressure and flow in this cavity, making the oil fume exhaust more smoothly. In addition, in order to limit the height of the whole machine in the second state and make the size of the whole machine small enough in the non-oil fume state, the distance H2 between the air outlet of the fan 4 and the bottom of the lower box body 2 satisfies: 0.5 ≤ H2 / (L1 + L2 + L3) ≤ 0.8.

[0041] In the first state, for the distance H1 between the air outlet of the fan 4 and the bottom of the air inlet body 3, if the height of the oil cup 9 is ignored, the distance between the air outlet of the fan 4 and the bottom of the lower box body 2 can also be approximately H1. And it satisfies H1 - H2 ≥ 250 mm, H1 - H2 - L3 ≥ 150 mm. In this way, the minimum descending stroke of the whole machine and the minimum descending stroke of the lower box body 2 can be limited, ensuring that the negative pressure area can descend a sufficient distance, and thus effectively improving the oil fume suction effect.

[0042] In the first state, i.e., the high airflow condition, the height of the air inlet 3 extending downwards from the bottom of the lower housing 2 is h2, and the downward stroke of the lower housing 2 from the second state to the first state is h3. The relationship between h2 and h3 satisfies: 0.3 ≤ h2 / h3 ≤ 1. Furthermore, the distance H1 between the air outlet of the fan 4 and the bottom of the air inlet 3 satisfies the relationship between L1, L2, and L3: 0.75 ≤ H1 / (L1+L2+L3) < 1. Through these two positional constraints, the overall height of the range hood under high airflow conditions can be limited, bringing the negative pressure area closer to the smoke source.

[0043] The specification and claims of this invention use terms indicating direction, 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 terms indicating direction 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.

[0044] 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 ceiling-mounted range hood, comprising an upper cabinet (1) having a height of LI, a lower cabinet (2) having a height of L2, and an air inlet body (3) of a main body portion having a height of L3, the lower cabinet (2) being provided on the upper cabinet (1), and the air inlet body (3) being provided on the lower cabinet (2), characterized in that: A fan (4) is installed inside the upper housing (1), and the range hood has at least two states. In the first state, the top of the lower box (2) is connected to the bottom of the upper box (1), and the air inlet (3) extends out from the bottom of the lower box (2) and descends to the lowest position; In the second state, the lower housing (2) is raised to its highest position so that the fan (4) is at least partially located inside the lower housing (2), and the air inlet (3) is raised to its highest position and is at least partially located inside the lower housing (2). The distance H2 between the air outlet of the fan (4) and the bottom of the lower housing (2) satisfies L1+L3<H2≤aL2, where 1<a≤1.

8. In the first state, the height of the air inlet (3) extending downward from the bottom of the lower housing (2) is h2. The descent stroke of the lower housing (2) from the second state to the first state is h3. The relationship between h2 and h3 satisfies: 0.3≤h2 / h3≤1. An oil cup (9) is installed at the bottom of the air inlet (3). In the second state, the oil cup (9) extends at least partially into the interior of the lower housing (2).

2. A ceiling-mounted range hood comprising an upper cabinet (1) having a height of LI, a lower cabinet (2) having a height of L2, and an air inlet body (3) of a main body portion having a height of L3, the lower cabinet (2) being provided on the upper cabinet (1), and the air inlet body (3) being provided on the lower cabinet (2), characterized in that: A fan (4) is installed inside the upper housing (1), and the range hood has at least two states. In the first state, the top of the lower box (2) is connected to the bottom of the upper box (1), and the air inlet (3) extends out from the bottom of the lower box (2) and descends to the lowest position; In the second state, the lower housing (2) is raised to the highest position so that the fan (4) is at least partially located inside the lower housing (2), and the air inlet (3) is raised to the highest position and is at least partially located inside the lower housing (2). The distance H3 between the air outlet of the fan (4) and the bottom of the air inlet (3) satisfies L1+L3<H3, and the distance H2 between the air outlet of the fan (4) and the bottom of the lower housing (2) satisfies H2≤aL2, where 1<a≤1.

8. In the first state, the height of the air inlet (3) extending downward from the bottom of the lower housing (2) is h2, and the descent stroke of the lower housing (2) from the second state to the first state is h3. The relationship between h2 and h3 is: 0.3≤h2 / h3≤1; The lower housing (2) moves up and down relative to the upper housing (1) under the drive of the drive mechanism, and the air inlet (3) moves up and down relative to the lower housing (2) under the drive of the drive mechanism.

3. The lifting hood according to claim 1 or 2, characterized in that: In the second state, there is a gap between the horizontal plane at the lowest end of the fan (4) and the horizontal plane at the highest position of the air inlet body (3).

4. The lifting type range hood according to claim 3, characterized in that: The height h1 of the gap satisfies: 0 < h1 ≤ 80 mm.

5. The lifting type range hood according to claim 1 or 2, characterized in that: In the second state, the fan (4) and the lower housing (2) have overlapping parts in the vertical direction, and the height of the overlapping part accounts for 40% to 80% of the height of the upper housing (1).

6. The lifting hood according to claim 1 or 2, characterized in that: In the first state, the distance H1 between the air outlet of the fan (4) and the bottom of the air inlet (3) satisfies the following condition: 0.75≤H1 / (L1+L2+L3)<1.

7. The lifting hood according to claim 1 or 2, characterized in that: In the second state, the distance H2 between the air outlet of the fan (4) and the bottom of the lower box (2) satisfies the following condition: 0.5≤H2 / (L1+L2+L3) ≤0.

8.

8. The lifting type range hood according to claim 1 or 2, characterized in that: During any time period during the lifting and lowering process of the lower housing (2) and the air inlet (3), the displacement of the lower housing (2) relative to the upper housing (1) is greater than the displacement of the air inlet (3) relative to the lower housing (2).

9. The lifting type range hood according to claim 1 or 2, characterized in that: The lower housing (2) includes a first air inlet channel (6) and a second air inlet channel (7) that are interconnected, with the first air inlet channel (6) located below and behind the second air inlet channel (7).

10. The lifting hood according to claim 9, characterized in that: In states other than the first state, the air intake (3) is at least partially located in the first air intake channel (6), and the fan (4) is at least partially located in the second air intake channel (7).

11. The lifting hood according to claim 9, characterized in that: The width W2 of the second air inlet channel (7) in the front-to-back direction and the width W1 of the first air inlet channel (6) in the front-to-back direction satisfy: W2≥1.5W1.

12. The lifting hood according to claim 10, characterized in that: The upper housing (1) also includes a fan frame (5). A third air inlet channel (8) is provided between the air inlet of the fan (4) and the rear plate of the fan frame (5). The width W1 of the first air inlet channel (6) in the front-to-back direction is greater than the width W3 of the third air inlet channel (8) in the front-to-back direction.

13. The lifting hood according to claim 1, characterized in that: In the second state, the oil cup (9) is fully inserted into the lower box (2) so that the bottom of the oil cup (9) is flush with or higher than the bottom of the lower box (2).

14. The lifting range hood according to claim 1 or 2, characterized in that: In the first state, the distance H1 between the air outlet of the fan (4) and the bottom of the air inlet (3) satisfies: H1-H2≥250mm, H1-H2-L3≥150mm.

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