A noise reduction structure and a lifting type range hood using the same

Abstract

A kind of noise reduction structure and the lifting type range hood of application this noise reduction structure, noise reduction structure includes upper installation support piece, lower installation support piece and the telescopic sound-absorbing member being connected between upper installation support piece and lower installation support piece, by the relative movement of upper installation support piece and lower installation support piece and drive shell telescopic sound-absorbing member synchronous telescopic motion, the lower box of this lifting type range hood is formed with air inlet chamber, the inside installation of air inlet chamber is described noise reduction structure, the lower installation support piece of noise reduction structure is fixed on the lower box and can keep synchronous lifting motion with lower box, upper installation support piece is fixed on upper box.The advantage of the present application is that: when starting, along with the lower box moving downwards, telescopic sound-absorbing member is unfolded and plays the role of noise reduction, during the process of shutdown, telescopic sound-absorbing member is folded along with the lower box and synchronously, after telescopic sound-absorbing member is extruded, the oil stored can be extruded, realize self-cleaning.

Description

Technical Field

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

[0002] A range hood is a kitchen appliance used to purify the kitchen environment. It operates on the principles of fluid dynamics, and the noise it generates during operation can affect cooking experiences and health. Sound quality is a crucial performance indicator for range hoods, directly impacting product quality and the user's cooking experience. Range hood noise primarily originates from impeller rotation noise and broadband vortex noise. Existing range hoods exhibit significant vortex formation, with varying characteristics under different operating conditions, necessitating higher noise reduction standards. Current solutions commonly involve optimizing the fan system's volute and impeller structures, or incorporating noise reduction measures such as sound-absorbing cotton. Conventional noise reduction solutions typically involve placing sound-absorbing cotton inside a robust sound-absorbing box (sheet metal or plastic) to form a sound-absorbing assembly, which is then fixed to the overall structure of the unit. For example, the Chinese utility model patent with patent number 202122994200.1 (authorization announcement number CN 216557295U) discloses a "Noise Reduction Range Hood". The range hood's fan frame includes a first side plate and a second side plate arranged at relatively intervals. The fan system is located inside the fan frame. The volute includes a front cover plate opposite to the first side plate and a rear cover plate opposite to the second side plate. The noise reduction device includes a noise reduction plate, which is located on the outside of at least one of the front cover plate and the rear cover plate. The noise reduction plate is arranged at relatively intervals with the corresponding front cover plate or rear cover plate to define an installation gap. The noise reduction plate is provided with sound-absorbing holes communicating with the installation gap, and the installation gap is filled with sound-absorbing elements.

[0003] While using sound-absorbing cotton for noise reduction is a common and relatively effective method for range hoods, it presents challenges for lift-type range hoods. Due to overlapping and moving parts, when installation gaps are tight, the structural limitations of the sound-absorbing box assembly can cause interference between it and other components during the machine's movement, rendering it unusable or limiting its size. Furthermore, because the sound-absorbing box assembly is constantly exposed to an oily environment, a large amount of oil accumulates in the sound-absorbing cotton, damaging its porous structure and thus affecting its noise reduction effect. Summary of the Invention

[0004] The first technical problem to be solved by the present invention is to provide a noise reduction structure that has a large noise reduction area when unfolded and a small volume when folded, in light of the above-mentioned existing technology.

[0005] The second technical problem to be solved by the present invention is to provide a liftable range hood with good noise reduction effect and a noise reduction structure that can achieve self-cleaning, in view of the above-mentioned existing technology.

[0006] The technical solution adopted by the present invention to solve the first technical problem mentioned above is as follows: The noise reduction structure is characterized in that it includes an upper mounting support, a lower mounting support, and a retractable sound-absorbing component connected between the upper mounting support and the lower mounting support. One of the upper mounting support and the lower mounting support is a fixed component, and the other is a movable component. The retractable sound-absorbing component is driven to perform synchronous retraction and extension movements by the relative movement of the upper mounting support and the lower mounting support.

[0007] The telescopic oil-absorbing component of this noise reduction structure can expand or retract synchronously with the relative movement of the upper and lower mounting supports. When expanded, it forms a larger noise reduction area and has a better noise reduction effect, while when retracted, it has a smaller volume.

[0008] The retractable sound-absorbing component can have various structures. Preferably, the retractable sound-absorbing component is a wave-shaped sound-absorbing cotton.

[0009] In order to enable the retractable sound-absorbing component to expand and contract smoothly, a limiting guide is also included, which extends vertically through the retractable sound-absorbing component and the top of the limiting guide is higher than the upper mounting support.

[0010] The limiting guide can have various structures. Preferably, the limiting guide includes a vertical guide rod and a horizontal top rod. The vertical guide rod is vertically arranged, and there are at least two vertical guide rods that pass vertically through the retractable sound-absorbing component. The horizontal top rod is located above the upper mounting support, and the top end of the vertical guide rod passes through the upper mounting support and is connected to the horizontal top rod.

[0011] The technical solution adopted by the present invention to solve the second technical problem mentioned above is as follows: the lifting range hood includes an upper box and a lower box. A fan is installed inside the upper box, and the lower box is located on the upper box and can move up and down relative to the upper box. The lower box has an air inlet cavity that communicates with the air inlet of the fan. The noise reduction structure is installed inside the air inlet cavity. The lower mounting support of the noise reduction structure is fixed on the lower box and can move up and down synchronously with the lower box. The upper mounting support is fixed on the upper box.

[0012] To ensure the oil-absorbing cotton of the noise-reducing structure retracts and expands synchronously with the lower housing, an oil guide plate is installed inside the lower housing, rising and falling in sync with it. The oil guide plate extends from front to back, and the noise-reducing structure is positioned above it. A lower mounting support for the noise-reducing structure is fixed to the front side of the oil guide plate. The upper housing has a front cover for the fan frame, and the lower mounting support is fixed to the bottom of this front cover. With this configuration, when the range hood is in operation, the sound-absorbing cotton of the noise-reducing structure expands as the lower housing descends, achieving a noise reduction effect. When not in operation, as the lower housing rises, the sound-absorbing cotton overlaps, allowing any oil residue adhering to it to fall onto the oil guide plate.

[0013] To avoid interference between the noise reduction structure and the fan during the lower housing lifting process, the noise reduction structure is located entirely in front of the fan.

[0014] In order to enable the oil guide plate to move up and down synchronously with the lower housing, the front side of the oil guide plate is folded upward to form an upper front plate. The upper front plate is fixed inside the lower housing, and the noise reduction structure is located on the inner side of the upper front plate and close to the upper front plate.

[0015] To further improve the noise reduction effect and reduce the overall height of the machine when it is off, the oil guide plate has a concave pressing structure in the middle, and the bottom of the fan volute is wrapped with noise-reducing and sound-absorbing cotton. When the lower housing is raised to the highest position, the noise-reducing and sound-absorbing cotton is located inside the pressing structure.

[0016] To further improve the noise reduction effect, a lower front plate is installed below the oil guide plate. The lower front plate is vertically arranged, and its upper edge is fixed to the rear edge of the oil guide plate. A noise reduction cavity with a forward-concave shape is formed on the rear side of the lower front plate. A noise reduction plate is covered on the noise reduction cavity, and noise reduction holes are opened on the noise reduction plate.

[0017] In order to pour the oil on the oil guide plate into the oil cup, the lower box is provided with an air inlet. The air inlet can move up and down relative to the lower box. An oil filter plate is installed on the top of the air inlet, and an oil cup is installed on the bottom of the air inlet. The projection of the rear edge of the oil guide plate in the vertical direction falls on the oil filter plate.

[0018] Further preferably, the air inlet cavity includes an upper air inlet cavity and a lower air inlet cavity that are interconnected. The upper air inlet cavity is formed above the oil guide plate. The noise reduction structure is installed in the upper air inlet cavity. An opening is formed between the rear edge of the oil guide plate and the back plate of the lower housing. The opening extends downward to form the lower air inlet cavity. The air inlet body has an air inlet channel inside. The air inlet channel is connected to the air inlet of the fan through the lower air inlet cavity and the upper air inlet cavity. This design allows cooking fumes to enter the upper air intake chamber through the narrow lower air intake chamber, and then into the upper housing. Because the lower air intake chamber is narrower, the faster flow of fumes can drive the external airflow, giving the fumes a greater backward velocity within the same timeframe, preventing them from escaping. However, this also causes turbulence, resulting in uneven fume flow at the air inlet, affecting the fume extraction effect. The wider upper air intake chamber, located downstream of the airflow passing through the lower chamber, can create a highly efficient pressure-stabilizing chamber due to its larger volume. This chamber buffers and stabilizes the airflow, ensuring a relatively uniform wind speed at the air inlet and preventing fumes from escaping from the sides of the range hood. Furthermore, grease dripping from the upper housing into the lower housing can cause splashing, which is difficult to manage, especially when there is a lot of condensed oil inside the fan system. The wider upper air intake chamber effectively reduces the wind speed, minimizing the impact of airflow on the trajectory of oil droplets and preventing splashing of oil droplets dripping from the volute.

[0019] The upper and lower air inlet chambers form a variable cross-section air inlet channel, effectively blocking the direct transmission of fan system noise. By simulating the principle of reactive noise cancellation, sound waves emitted from the fan are reflected multiple times within the spacious upper air inlet chamber 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. Additionally, this airflow buffer chamber, simulating a static pressure box, can improve the unsteady flow separation caused by inlet distortion, thereby reducing pressure pulsation and improving sound quality.

[0020] Further preferably, when the lower housing is lowered to its lowest position, the fan is positioned above the upper air inlet cavity, and the air inlet body extends downwards from the lower housing and is located below the lower air inlet cavity. When the lower housing is raised to its highest position, the fan is at least partially located within the upper air inlet cavity, and the air inlet body extends at least partially upwards into the lower air inlet cavity. This configuration allows the lower housing to move vertically relative to the upper housing, and the air inlet body can also move vertically. The upper air inlet cavity can accommodate the upper housing, and the lower air inlet cavity can accommodate the air inlet body, resulting in a smaller overall size, more compact structure, and smaller space occupation for the range hood when not in operation.

[0021] Further preferably, the lower housing and the air inlet are synchronously raised and lowered under the drive of the drive mechanism. This configuration enables the lower housing and the air inlet to move in unison.

[0022] Compared with the prior art, the advantages of the present invention are as follows: the noise reduction structure is installed in the air inlet cavity of the lower box of the lifting range hood. The lower mounting support of the noise reduction structure is fixed on the lower box and can move up and down synchronously with the lower box. The upper mounting support is fixed on the upper box. When the machine is turned on, as the lower box moves downward, the telescopic sound-absorbing component of the noise reduction structure unfolds to play a noise reduction role. During the shutdown process, the telescopic sound-absorbing component retracts synchronously with the lower box rising. Furthermore, after the telescopic sound-absorbing component is squeezed, the stored oil can be squeezed out, realizing self-cleaning. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the noise reduction structure according to an embodiment of the present invention (in its unfolded state);

[0024] Figure 2 This is a schematic diagram of the noise reduction structure according to an embodiment of the present invention (in its retracted state);

[0025] Figure 3 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);

[0026] Figure 4 for Figure 3 The diagram shown is a schematic of the internal structure of the range hood.

[0027] Figure 5 for Figure 4 An enlarged schematic diagram of part A in the middle;

[0028] Figure 6 This is a schematic diagram of the structure of a range hood according to an embodiment of the present invention (in its working state);

[0029] Figure 7 for Figure 6 The diagram shown is a schematic of the internal structure of the range hood.

[0030] Figure 8 for Figure 6 The diagram shows the internal structure of the range hood from another angle. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0032] like Figure 1 and Figure 2As shown, the noise reduction structure of this embodiment includes an upper mounting support 11, a lower mounting support 12, a retractable sound-absorbing component, and a limiting guide 14. One of the upper mounting support 11 and the lower mounting support 12 is a fixed component, and the other is a movable component. The retractable sound-absorbing component is a wave-shaped oil-absorbing cotton 13, which is connected between the upper mounting support 11 and the lower mounting support 12. The relative movement of the upper mounting support 11 and the lower mounting support 12 causes the sound-absorbing cotton 13 to move synchronously. The limiting guide 14 passes vertically through the sound-absorbing cotton 13, and the top of the limiting guide 14 is higher than the upper mounting support 11. The limiting guide 14 includes a vertical guide rod 141 and a horizontal top rod 142. The vertical guide rods 141 are vertically arranged, and there are at least two vertical guide rods 141 that pass vertically through the sound-absorbing cotton 13. The horizontal top rod 142 is located above the upper mounting support 11, and the top end of the vertical guide rod 141 passes through the upper mounting support 11 and connects to the horizontal top rod 142. Figure 1 As shown, during noise reduction, the upper mounting support 11 and the lower mounting support 12 move away from each other, and the sound-absorbing cotton 13 unfolds. Figure 2 As shown, when the device is retracted, the upper mounting support 11 and the lower mounting support 12 move closer together, and the sound-absorbing cotton 13 is compressed.

[0033] like Figures 3 to 8 As shown, the lift-type range hood of this embodiment includes an upper housing 1, a lower housing 2, and an air inlet 3. A fan 4 is installed inside the upper housing. The lower housing 2 is mounted on the upper housing 1 and can move up and down relative to the upper housing 1. Furthermore, the lower housing 2 encloses the upper housing 1. Figure 7 The direction indicated by arrow B is rearward. The air inlet 3 is housed at the rear of the lower housing 2 and can move up and down relative to the lower housing 2. An oil cup 10 is installed at the bottom of the air inlet 3. 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 an independent drive mechanism.

[0034] The lower housing 2 has an air inlet chamber 5 inside, which is connected to the air inlet of the fan 4. The air inlet chamber 5 includes an upper air inlet chamber 51 and a lower air inlet chamber 52 that are interconnected. An oil guide plate 6 is installed inside the lower housing 2, extending from front to back. The upper air inlet chamber 51 is formed above the oil guide plate 6. An opening is formed between the rear edge of the oil guide plate 6 and the back plate 21 of the lower housing 2, and the opening extends downward to form the lower air inlet chamber 52. The air inlet body 3 has an air inlet channel 32 inside, which is connected to the air inlet of the fan 4 through the lower air inlet chamber 52 and the upper air inlet chamber 51. An oil filter plate 31 is installed on the top of the air inlet body 3, and an oil cup 10 is installed on the bottom of the air inlet body 3. The vertical projection of the rear edge of the oil guide plate 6 falls on the oil filter plate 31, and the oil falling on the oil guide plate 6 can fall into the oil cup 10 through the oil filter plate 31.

[0035] In the working state, the lower housing 2 is lowered to its lowest position, the fan 4 is positioned above the upper air inlet chamber 51, and the air inlet body 3 extends downward from the lower housing 2 and is located below the lower air inlet chamber 52. The air inlet of the air inlet body 3 is fully exposed, the negative pressure zone is lowered, and it is closer to the smoke source, ensuring the performance requirements of the entire machine. In the non-working state, the lower housing 2 is raised to its highest position, the fan 4 is at least partially located in the upper air inlet chamber, and the air inlet body 3 extends upward into the lower air inlet chamber 52 at least partially. In this embodiment, the air inlet body 3 extends entirely into the lower air inlet chamber 52, and the lower surface of the oil cup 10 is flush with the lower surface of the lower housing 2, reducing the overall height of the machine, occupying less kitchen space, and making the entire machine simpler and more aesthetically pleasing.

[0036] like Figure 6 and 7 As shown, after the fumes are drawn in through the air inlet channel 32 of the air inlet body 3, they enter the upper air inlet cavity 51 through the narrow lower air inlet cavity 52, and then enter the fan 4 inside the upper housing 1. Because the front and rear width of the lower air inlet cavity 52 is relatively narrow, the fumes flow velocity is fast, which can drive the external flow field to achieve faster airflow and give the fumes a greater backward velocity in the same amount of time, preventing the fumes from escaping. However, at the same time, the airflow here will also be turbulent, causing the fumes flow velocity at the air inlet of the air inlet body 3 to be uneven, affecting the fume extraction effect. The wide upper air inlet cavity 51 is located downstream of the airflow passing through the lower air inlet cavity 52. ​​At this time, the upper air inlet cavity 51, due to its large volume, can construct an efficient pressure stabilizing cavity, so that the airflow is buffered and stabilized in the pressure stabilizing cavity, ensuring that there is a basically the same wind speed at the air inlet, and avoiding the problem of fumes escaping from both sides of the range hood. Furthermore, the oil stains inside the upper housing 1 will drip into the lower housing 2, and the problem of oil splashing and falling is difficult to deal with, especially when there is a lot of condensed oil inside the fan 4. The wide upper air inlet 51 can effectively reduce the wind speed, reduce the influence of airflow on the trajectory of oil droplets, and prevent oil droplets dripping from the volute from splashing.

[0037] Furthermore, the structures of the upper air inlet cavity 51 and the lower air inlet cavity 52 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 4 are reflected multiple times inside the wide upper air inlet cavity 51 and thus canceled out. Therefore, a variable cross-section acoustic impedance is constructed to reduce the energy of sound propagating from the air inlet of the fan 4 to the air inlet of the air inlet body 3. 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.

[0038] In this embodiment, the front side of the oil guide plate 6 is folded upward to form an upper front plate 61. The upper front plate 61 is fixed inside the lower housing 2, and the upper front plate 61 and the oil guide plate 6 are an integral part, so the oil guide plate 6 and the upper front plate 61 can move up and down synchronously with the lower housing 2. In this embodiment, the noise reduction structure is installed inside the upper air inlet cavity 51, that is, above the oil guide plate 6. The noise reduction structure is located on the inner side of the upper front plate 61 and close to the upper front plate 61. The entire noise reduction structure is located on the front side of the fan 4, avoiding interference between the noise reduction structure and the fan 4 during the lifting and lowering process. In addition, a certain gap is always maintained between the rear side of the noise reduction structure and the front cover plate 40 of the fan 4's volute, ensuring the air intake requirements of the front air inlet of the fan 4.

[0039] like Figure 5 As shown, the lower mounting support 12 of the noise reduction structure is fixed to the front side of the oil guide plate 6, and the upper mounting support 11 is fixed to the bottom of the fan frame front cover plate 100 of the upper housing 1. Since the fan frame front cover plate 100 is a fixed part, as the lower housing 2 and the oil guide plate 6 move up and down relative to the upper housing 1, the lower mounting support 12 moves up and down synchronously, thereby driving the sound-absorbing cotton 13 to retract and expand.

[0040] When the machine is turned on, as the lower housing 2 moves downward relative to the upper housing 1, the lower mounting support 11 of the noise reduction structure moves away from the upper mounting support 12 under the action of the oil guide plate 6, causing the sound-absorbing cotton 13 to unfold. Since the folded, retractable sound-absorbing cotton has more noise reduction structures than sound-absorbing cotton of the same spatial area, it can reduce noise more effectively. At the same time, the sound-absorbing cotton 13 is located on the rear side of the front panel of the lower housing 2 and is basically at the same level as the user's head when cooking. The user's perception of noise is more obvious in this location. Compared with the distribution of sound-absorbing cotton in other locations, the addition of sound-absorbing cotton 13 in this location can significantly improve the user's noise reduction experience.

[0041] During the shutdown process, as the lower housing 2 moves upward relative to the upper housing 1, the lower mounting support 11 of the noise reduction structure moves upward to approach the upper mounting support 12 under the influence of the oil guide plate 6. The retractable sound-absorbing cotton 13 gradually overlaps. At this time, by setting the minimum distance between the bottom of the fan frame front cover 100 and the oil guide plate 6, the fan frame front cover 100 can compress the overlapped sound-absorbing cotton 13, squeezing out the oil stored in the sound-absorbing cotton 13, thus achieving the "self-cleaning" function of the sound-absorbing cotton. The squeezed-out oil can flow onto the oil guide plate 6, and then through the air inlet 3 into the oil cup 10. Furthermore, to avoid damage to the sound-absorbing cotton noise reduction structure due to prolonged pressure, the fan frame front cover 100 can be set to move in the opposite direction after compressing the sound-absorbing cotton 13, unfolding the compressed sound-absorbing cotton 13 again, ensuring that it can recover its original state to a certain extent, thereby effectively ensuring the long-term efficient working state of the sound-absorbing cotton.

[0042] like Figure 4 , Figure 6 and Figure 8 As shown, the oil guide plate 6 has a recessed molding structure 62 formed in the middle, and the bottom of the fan 4's volute is wrapped with noise-reducing and sound-absorbing cotton 7. When the lower housing 2 is raised to its highest position, the noise-reducing and sound-absorbing cotton 7 sits inside the molding structure 62. Using the noise-reducing and sound-absorbing cotton 7 can further reduce the noise of the fan 4. In addition, noise-reducing blocks 63 are also installed on the oil guide plate 6 to further reduce noise.

[0043] A lower front plate 8 is installed below the oil guide plate 6. The lower front plate 8 is vertically positioned, and its upper edge is fixed to the rear edge of the oil guide plate 6. A noise reduction cavity 81 with a forward-recessed shape is formed on the rear side of the lower front plate 8. A noise reduction plate 9 is covered on the noise reduction cavity 81, and noise reduction holes 91 are opened on the noise reduction plate 9. The noise reduction cavity 81 and the noise reduction holes 91 cooperate to further reduce noise.

[0044] 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.

Claims

1. A liftable range hood, comprising an upper housing (1) and a lower housing (2), wherein a fan (4) is installed inside the upper housing (1), and the lower housing (2) is disposed on the upper housing (1) and is capable of lifting relative to the upper housing (1), characterized in that: The lower housing (2) forms an air inlet cavity (5) that communicates with the air inlet of the fan (4). A noise reduction structure is installed inside the air inlet cavity (5). The noise reduction structure includes an upper mounting support (11), a lower mounting support (12), and a retractable sound-absorbing component connected between the upper mounting support (11) and the lower mounting support (12). One of the upper mounting support (11) and the lower mounting support (12) is a fixed component, and the other is a movable component. The retractable sound-absorbing component is driven to perform synchronous retraction and extension movements by the relative movement of the upper mounting support (11) and the lower mounting support (12). The lower mounting support (12) of the noise reduction structure is fixed to the lower housing. (2) The upper box (1) can move synchronously with the lower box (2). The upper mounting support (11) is fixed on the upper box (1). The lower box (2) is equipped with an oil guide plate (6) that moves synchronously with the lower box (2). The oil guide plate (6) extends from front to back. The noise reduction structure is located above the oil guide plate (6). The lower mounting support (12) of the noise reduction structure is fixed on the front side of the oil guide plate (6). The upper box (1) has a fan frame front cover plate (100). The lower mounting support (12) is fixed at the bottom of the fan frame front cover plate (100). The lower box (2) and the air inlet (3) move synchronously under the drive of the drive mechanism.

2. The lifting range hood according to claim 1, characterized in that: The retractable sound-absorbing component is a wave-shaped oil-absorbing cotton (13).

3. The lifting range hood according to claim 1, characterized in that: It also includes a limiting guide (14) that passes vertically through the retractable sound-absorbing member, and the top of the limiting guide (14) is higher than the upper mounting support (11).

4. The lifting range hood according to claim 3, characterized in that: The limiting guide (14) includes a vertical guide rod (141) and a horizontal top rod (142). The vertical guide rod (141) is vertically arranged, and there are at least two vertical guide rods (141) that pass vertically through the retractable sound-absorbing component. The horizontal top rod (142) is located above the upper mounting support (11). The top end of the vertical guide rod (141) passes through the upper mounting support (11) and is connected to the horizontal top rod (142).

5. The lifting range hood according to claim 1, characterized in that: The noise reduction structure is located on the front side of the fan (4).

6. The lifting range hood according to claim 1, characterized in that: The front side of the oil guide plate (6) is folded upward to form an upper front plate (61). The upper front plate (61) is fixed inside the lower housing (2). The noise reduction structure is located on the inner side of the upper front plate (61) and close to the upper front plate (61).

7. The lifting range hood according to claim 1, characterized in that: The oil guide plate (6) has a concave molding structure (62) formed in the middle. The bottom of the volute of the fan (4) is wrapped with noise-reducing and sound-absorbing cotton (7). When the lower box (2) is raised to the highest position, the noise-reducing and sound-absorbing cotton (7) sits in the molding structure (62).

8. The lifting range hood according to claim 1, characterized in that: A lower front plate (8) is installed below the oil guide plate (6). The lower front plate (8) is vertically arranged, and the upper edge of the lower front plate (8) is fixed on the rear edge of the oil guide plate (6). A noise reduction cavity (81) that is concave inward is formed on the rear side of the lower front plate (8). A noise reduction plate (9) is covered on the noise reduction cavity (81), and a noise reduction hole (91) is opened on the noise reduction plate (9).

9. The lifting range hood according to claim 1, characterized in that: The lower housing (2) is provided with an air inlet (3), which can move up and down relative to the lower housing (2). An oil filter plate (31) is installed on the top of the air inlet (3), and an oil cup (10) is installed on the bottom of the air inlet (3). The projection of the rear edge of the oil guide plate (6) in the vertical direction falls on the oil filter plate (31).

10. The lifting range hood according to claim 9, characterized in that: The air inlet cavity (5) includes an upper air inlet cavity (51) and a lower air inlet cavity (52) that are interconnected. The upper air inlet cavity (51) is formed above the oil guide plate (6). The noise reduction structure is installed in the upper air inlet cavity (51). An opening is formed between the rear edge of the oil guide plate (6) and the back plate (21) of the lower housing (2). The opening extends downward to form the lower air inlet cavity (52). The air inlet body (3) has an air inlet channel (32) inside. The air inlet channel is connected to the air inlet of the fan (4) through the lower air inlet cavity (52) and the upper air inlet cavity (51).

11. The lifting range hood according to claim 10, characterized in that: When the lower housing (2) is lowered to its lowest position, the fan (4) is positioned above the upper air inlet cavity (51), and the air inlet body (3) extends downward from the lower housing (2) and is located below the lower air inlet cavity (52). When the lower housing (2) is raised to its highest position, the fan (4) is at least partially located in the upper air inlet cavity, and the air inlet body (3) extends upward into the lower air inlet cavity (52).

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