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, the air inlet body is arranged on the lower box, and the upper box is internally provided with a fan. 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 is extended from the bottom of the lower box and is lowered to the lowest position. 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, and 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 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 limited. For a range hood with a two-stage lifting structure, it's necessary to ensure each lifting component has sufficient downward travel to significantly lower the negative pressure zone and create a direct suction and exhaust channel during operation, thereby improving fume extraction. Simultaneously, it's necessary to consider reducing the overall height of the unit when each lifting component is raised, resulting in a more compact and streamlined structure for concealed installation. In conclusion, further improvements to the existing lifting range hood structure are needed. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a lift-up range hood that can form a direct suction and exhaust channel inside the range hood when it is in operation and has a low overall height when it is not in operation, in view of the above-mentioned existing technology.

[0004] The technical solution adopted by the present invention to solve the above-mentioned technical problem is as follows: The lifting range hood includes an upper box, a lower box, and an air inlet. The lower box is disposed on the upper box and can move up and down relative to the upper box. The air inlet is disposed on the lower box and can move up and down relative to the lower box. A fan is installed in the upper box. The fan is vertically arranged and includes a volute. The characteristic feature is that:

[0005] Establish a rectangular coordinate system on section M of the range hood. Section M passes through the bottom of the volute and is parallel to the side panel of the upper housing. Set the X-axis and Y-axis on section M. The X-axis passes through the bottom of the volute and is parallel to the horizontal plane, and the Y-axis passes through the bottom of the rear cover of the volute and is parallel to the back panel of the upper housing.

[0006] In section M, a first flow channel is formed inside the main body of the air inlet, a second flow channel is formed inside the lower housing, a main air inlet is located at the rear of the fan, and a third flow channel is formed between the main air inlet and the back plate of the upper housing. When both the lower housing and the air inlet are lowered to their lowest positions, the first flow channel is at least partially located in the fourth quadrant of the rectangular coordinate system, the second flow channel is at least partially located in the fourth quadrant of the rectangular coordinate system, and the third flow channel is located in the first quadrant of the rectangular coordinate system. When both the lower housing and the air inlet are raised to their highest positions, the first flow channel is entirely located in the fourth quadrant of the rectangular coordinate system or entirely located in both the fourth and third quadrants of the rectangular coordinate system, the second flow channel is partially located in the first quadrant and partially located in the fourth quadrant of the rectangular coordinate system, and the third flow channel is located in the first quadrant of the rectangular coordinate system.

[0007] With this configuration, when the lower casing and the air inlet are both at their lowest positions, the first, second, and third air channels are located in the fourth and first quadrants, respectively. This means that the directions of the first, second, and third air channels are consistent, and the airflow does not need to change its path direction too much when passing through them, achieving a direct suction and exhaust effect. Furthermore, when viewed from the front of the range hood, the width difference between the air inlet, lower casing, and upper casing is small, which also achieves a direct suction and exhaust effect. When both the lower casing and the air inlet are at their highest positions, part of the second flow channel falls into the first quadrant. Therefore, the second flow channel partially overlaps with the third flow channel. In the raised state, the lower casing overlaps more with the upper casing, achieving the effect of small overall size and less space occupation. In addition, when both the lower casing and the air inlet are at their highest positions, the first flow channel is still located in the fourth quadrant. It can be seen that the main body of the air inlet is always located below the fan. This allows the oil stains in the fan to be guided into the air inlet body along the natural downward trend, and then discharged from the inner cavity of the range hood. This avoids the accumulation of oil stains 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 inlet also acts as an oil guiding channel.

[0008] As a preferred embodiment, when both the lower housing and the air inlet are at their lowest positions, at least 80% of the first flow channel is located in the fourth quadrant in the X-axis direction. With this configuration, the front panel of the air inlet is positioned further forward than the rear cover of the volute, allowing the air inlet to collect oil dripping from the rear cover of the volute.

[0009] As another preferred option, when both the lower housing and the air inlet are at their lowest positions, the first flow channel is completely located within the fourth quadrant in the X-axis direction. With this configuration, the air inlet is located entirely below and behind the fan, allowing the oil fume airflow to flow vertically upwards towards the fan's main air inlet without obstruction, thus achieving a direct suction and exhaust effect and improving the oil fume extraction efficiency.

[0010] Preferably, the fan has an auxiliary air inlet on its front side. In section M, a fourth flow channel is formed between the auxiliary air inlet and the front panel of the upper housing. The fourth flow channel is located in the second quadrant of the rectangular coordinate system. With the auxiliary air inlet provided, the fumes in the second flow channel can be discharged more quickly during operation.

[0011] Further optimized, when both the lower casing and the air inlet are lowered to their lowest positions, the second flow channel includes a first part and a second part. The first part is at least partially located in the third quadrant, and the second part is at least partially located in the fourth quadrant, with the first part corresponding to the fourth flow channel. This arrangement facilitates the smooth flow of air from the first part of the second flow channel into the fourth flow channel, and also allows the air inlet to be accommodated in the second part of the second flow channel when it rises, thus fully utilizing the internal space of the range hood and reducing the overall height of the unit.

[0012] Further preferably, the vertical projection of the fourth flow channel is entirely located within the first part. In this way, a direct suction and exhaust channel is also formed between the first part of the second flow channel and the fourth flow channel, which helps to improve the fume extraction effect.

[0013] Further preferably, a baffle is provided inside the lower housing, parallel to the back panel of the lower housing. A second section is formed between the baffle and the back panel of the lower housing. When both the lower housing and the air inlet are at their lowest positions, at least 75% of this second section is located in the fourth quadrant along the X-axis. This arrangement creates a direct suction and exhaust passage between the second section of the second flow channel and the third flow channel, facilitating rapid smoke extraction and improving the fume extraction effect.

[0014] Further optimization involves ensuring that, when both the lower casing and the air inlet are at their lowest positions, the width of the first part of the second flow channel is greater than the width of the second part on the X-axis. With this configuration, cooking fumes enter the first part through the narrow second part and then into the upper casing. Because the first part is narrower, the cooking fume flow is faster, which can drive the external flow field to achieve a faster airflow, giving the cooking fumes a greater backward velocity in the same amount of time, preventing them from escaping. However, this also causes turbulence in the airflow, resulting in uneven cooking fume velocity at the air inlet, affecting the fume extraction effect. The wider first part, located downstream of the second part, can create a highly efficient pressure-stabilizing chamber due to its larger volume. This allows the airflow to be buffered and stabilized within the pressure-stabilizing chamber, ensuring a relatively uniform wind speed at the air inlet and preventing smoke from escaping from both sides of the range hood. Furthermore, the oil stains inside the upper chamber will drip into the lower chamber, and the problem of oil splashing and drifting is difficult to deal with, especially when there is a lot of condensed oil inside the fan system. The wide first section can effectively reduce the wind speed, reduce the impact of airflow on the trajectory of oil droplets, and prevent oil droplets dripping from the volute from splashing.

[0015] Further optimization reveals that when both the lower housing and the air inlet are at their lowest positions, the width W2 of the first part and the width W1 of the second part satisfy the following condition on the X-axis: 1.1W1≤W2≤4W1. With this configuration, the structure of the first and second parts of the second flow channel forms a variable cross-section air inlet channel, effectively blocking the direct transmission of fan system noise. By simulating the principle of reactive noise reduction, sound waves emitted from the fan are reflected multiple times within the wide second part 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, 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.

[0016] Further preferred, when both the lower housing and the air inlet are lowered to their lowest positions, on the X-axis, the flow channel width W2 of the first part and the flow channel width W1 of the second part satisfy: 2W1≤W2≤3W1.

[0017] Preferably, the width of the fourth flow channel in the second quadrant is smaller than the width of the third flow channel in the first quadrant. This results in a wider flow channel on the main air inlet side of the fan and a narrower flow channel on the auxiliary air inlet side, leading to a more rational airflow distribution and improved fume extraction efficiency.

[0018] In order to form a direct suction and discharge channel, the first flow channel, the rear flow channel of the second flow channel, and the third flow channel are interconnected from bottom to top in the vertical direction.

[0019] Preferably, when the lower box body is lowered to the lowest position, the entire fan is located above the second flow channel. With this arrangement, the descending stroke of the lower box body is sufficiently large, and the negative pressure area can be moved down by a sufficient distance, thereby improving the effect of sucking oil fume.

[0020] Preferably, when the lower box body is raised to the highest position, at least part of the fan extends into the second flow channel. With this arrangement, the overall height of the range hood in a non-operating state can be reduced, the structure of the range hood is more compact, which is conducive to concealing the entire range hood in a cabinet.

[0021] Further preferably, when the lower box body is raised to the highest position, the height of the air inlet body located inside the lower box body is H1, the height of the upper box body located inside the lower box body is H2, and the height of the lower box body is H3, which satisfies H1+H2≥aH3, where a is 0.8, 0.85, 0.9 or 0.95. With this arrangement, in the non-operating state, the internal space of the lower box body can be fully utilized to accommodate the upper box body and the air inlet body, thereby reducing the overall height as much as possible.

[0022] Further preferably, when the lower box body is raised to the highest position, it satisfies H1+H2<H3. In this way, in the non-operating state, the air inlet body and the fan have no overlapping portion in the vertical direction, which facilitates the oil liquid on the fan to be guided onto the air inlet body.

[0023] In order to reduce the overall height of the whole machine in the non-operating state, when the lower box body is raised to the highest position, at least 50% of the fan is located in the second flow channel on the Y-axis.

[0024] In order to reduce the overall height of the whole machine in the non-operating state as much as possible, when the lower box body is raised to the highest position, at least 95% of the air inlet body is located in the second flow channel on the Y-axis.

[0025] In order to limit the minimum descending stroke of the whole machine, so that the negative pressure area can descend a sufficient distance, when the lower box body is lowered to the lowest position, the height of the fan is L1, the air inlet body is provided with an air inlet, the height from the bottommost end of the air inlet to the horizontal plane where the bottommost end of the fan is located is L2, which satisfies: L2≥bL1, where b is 1.3, 1.4, 1.5 or 1.6.

[0026] Compared with the prior art, the advantages of the present invention are as follows: This lift-up range hood establishes a rectangular coordinate system on the cross-section of the range hood, with a first flow channel inside the air inlet, a second flow channel inside the lower housing, and a third flow channel on the side of the main air inlet at the rear of the fan. In the descending state, the rear of the first flow channel, the second flow channel, and the third flow channel can form a direct suction and exhaust channel, thereby improving the smoke extraction effect. In the non-working state, as part of the second flow channel falls into the first quadrant and part falls into the fourth quadrant, the fan can enter the lower housing, and the air inlet can enter the lower housing, thereby reducing the overall height of the range hood, making the range hood structure simple and compact, which is conducive to hiding the whole machine in the kitchen cabinet, with high aesthetics and saving external kitchen space. Attached Figure Description

[0027] 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);

[0028] Figure 2 for Figure 1 The image shows a front view of the range hood.

[0029] Figure 3 for Figure 2 The image shows a sectional view of the range hood along the BB direction;

[0030] Figure 4 This is a schematic diagram of the air inlet body according to an embodiment of the present invention;

[0031] Figure 5 A schematic diagram of the structure of a range hood according to an embodiment of the invention (in working condition);

[0032] Figure 6 for Figure 5 The image shows a front view of the range hood.

[0033] Figure 7 for Figure 5 A three-dimensional sectional view of the range hood shown;

[0034] Figure 8 for Figure 6 The image shows a cross-sectional view of the range hood along the CC direction. Detailed Implementation

[0035] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] The solution in this embodiment is implemented when the range hood is installed along a vertical wall, such as... Figures 1 to 8As 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. 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 up and down synchronously under the drive of a set of drive mechanisms, or they can move independently under the drive of independent drive mechanisms. That is, the lower housing 2 can move up and down relative to the upper housing 1 under the action of the drive mechanism, and the air inlet 3 can move up and down relative to the lower housing 2 under the action of the drive mechanism.

[0037] A fan 4 is installed inside the upper housing 1. The fan 4 is a vertically arranged centrifugal fan. The vertical arrangement is not limited to being perpendicular to the horizontal plane; the angle between the fan and the horizontal plane can be 80°-100°. The fan 4 includes a volute 41, and the central axis of the impeller is located on the horizontal plane or at an angle of less than 10° to the horizontal plane.

[0038] The solutions in this embodiment are all described on cross-section M, such as... Figure 3 , 7 As shown in Figure 8, Figure 3 The direction indicated by the middle arrow A is backward. A rectangular coordinate system is established on the cross-section M of the range hood. This cross-section M passes through the bottom of the volute 41 and is parallel to the side panel of the upper housing 1. An X-axis and a Y-axis are set on cross-section M. The X-axis passes through the bottom of the volute 41, is parallel to the horizontal plane, and extends from front to back. The Y-axis passes through the bottom of the rear cover plate 411 of the volute, is parallel to the back panel 11 of the upper housing, and extends from bottom to top. Here, the side panel of the upper housing 1 refers to the left or right side panel of the upper housing 1. This side panel is perpendicular to the horizontal plane and perpendicular to the vertical plane where the back panel 11 of the upper housing is located. The vertical plane is perpendicular to the horizontal plane. Furthermore, when the volute 41 is vertically positioned, the bottom of the rear cover plate 411 is a straight line; when the volute 41 is inclined relative to the horizontal plane, the bottom of the rear cover plate 411 is a point.

[0039] In section M, a first flow channel 51 is formed inside the air inlet 3, a second flow channel 52 is formed inside the lower housing 2, a main air inlet 42 is located at the rear of the fan 4, an auxiliary air inlet 43 is located at the front of the fan 4, a third flow channel 53 is formed between the main air inlet 42 and the upper housing back plate 11, and a fourth flow channel 54 is formed between the auxiliary air inlet 43 and the upper housing front plate 12. The fourth flow channel 54 is located in the second quadrant of the rectangular coordinate system, and the first flow channel 51, the second flow channel 52, the third flow channel 53 and the fourth flow channel 54 are all fluidly connected. When both the lower housing 2 and the air inlet 3 are lowered to their lowest positions, the first flow channel 51 is at least partially located in the fourth quadrant of the rectangular coordinate system, the second flow channel 52 is at least partially located in the fourth quadrant of the rectangular coordinate system, and the third flow channel 53 is located in the first quadrant of the rectangular coordinate system. When both the lower housing 2 and the air inlet 3 are raised to their highest positions, the first flow channel 51 is entirely located in the fourth quadrant of the rectangular coordinate system or entirely located in both the fourth and third quadrants of the rectangular coordinate system, the second flow channel 52 is partially located in the first quadrant and partially located in the fourth quadrant of the rectangular coordinate system, and the third flow channel 53 is located in the first quadrant of the rectangular coordinate system. Therefore, in the descending state, the rear parts of the first flow channel 51, the second flow channel 52, and the third flow channel 53 can form a direct suction and exhaust channel, thereby improving the fume extraction effect. In the non-working state, as part of the second flow channel 52 falls into the first quadrant and part falls into the fourth quadrant, the fan 4 can enter the lower housing 2, and the air inlet 3 can enter the lower housing 2, thus reducing the overall height of the range hood. This makes the range hood structure simple and compact, facilitating its concealment in kitchen cabinets, resulting in a high aesthetic appeal and cost-effectiveness. To save external kitchen space, and when both the lower casing 2 and the air inlet 3 are at their highest positions, the first flow channel 51 is still located in the fourth quadrant. It can be seen that the main body 32 of the air inlet 3 is always located below the fan 4. This allows the oil stains in the fan 4 to be guided into the air inlet body along the natural downward trend, and then discharged from the inner cavity of the range hood. This avoids the accumulation of oil stains in the fan 4 or dripping into other places when the range hood is not in use, which would prevent them from being discharged in time. At this time, the air inlet 3 also acts as an oil guiding channel.

[0040] like Figure 4 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. An air 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 21. The air inlet 3 can move up and down relative to the lower housing 2 along the guide rail 9.

[0041] In this embodiment, an air inlet 31 is provided on the front side of the air inlet 3, and an oil cup 8 is installed at the bottom of the air inlet 3 to collect the oil flowing down from the air inlet 3. When both the lower housing 2 and the air inlet 3 are lowered to their lowest positions, at least 80% of the first flow channel 51 is located in the fourth quadrant in the X-axis direction. With this configuration, the front panel of the air inlet 3 is further forward than the rear cover plate 411 of the volute, and the air inlet 3 can collect the oil dripping from the rear cover plate 411 of the volute. The oil eventually enters the oil cup 8 through the air inlet 3. Furthermore, when both the lower housing 2 and the air inlet 3 are lowered to their lowest positions, the first flow channel 51 can also be completely located in the fourth quadrant in the X-axis direction. Thus, the air inlet 3 is located below and behind the fan 4. After passing through the air inlet 3, the oil fume airflow can flow vertically upward to the main air inlet 42 of the fan, and it will not be obstructed during the flow. That is, the directions of the first flow channel 51, the second flow channel 52 and the third flow channel 53 are consistent. When the airflow passes through the three, it does not need to change its path direction too much, forming a direct suction and direct exhaust effect, thereby improving the oil fume extraction effect.

[0042] like Figure 3 , 7 As shown in Figures 8 and 9, the second flow channel 52 in this embodiment includes a first part 521 and a second part 522. The lower housing 2 has a horizontally arranged oil guide plate 7 and a vertically arranged baffle 6 inside. In the vertical direction, the oil guide plate 7 is approximately located in the middle of the lower housing. The oil guide plate 7 can be horizontally arranged or slightly angled downwards from front to back. The oil guide plate 7 is located below the fan 4 and can collect the oil dripping from the fan 4. The air inlet 3 is located below and behind the oil guide plate 7, allowing the oil fumes on the oil guide plate 7 to flow into the oil cup 8 through the air inlet 3. The baffle 6 is located below the oil guide plate 7 and in front of the air inlet 3. The top of the baffle 6 is connected to the rear of the oil guide plate 7. The baffle 6 can be parallel to the back plate 21 of the lower housing or at a certain angle. Typically, the angle between the baffle 6 and the plumb line can be 0-10°.

[0043] Viewed in section M, the interior of the lower housing 2 is divided into a first part 521 and a second part 522 of the second flow channel 52 by the oil guide plate 7 and the baffle 6. The lower housing back plate 21, the lower housing front plate 22, and the oil guide plate 7 form the first part 511, which is relatively wide, meaning it is wider in the front-to-back direction. The lower housing front plate 22 can be either the front panel of the lower housing 2 or a plate formed by bending the front side of the oil guide plate 7 vertically upwards. In this embodiment, the lower housing front plate 22 is the latter, meaning it is an integral piece with the oil guide plate 7. The baffle 6 and the lower housing back plate 21 form the second part 522, which is relatively narrow, meaning it is narrower in the front-to-back direction. Thus, a variable cross-section flow channel is formed inside the lower housing 2. When both the lower housing 2 and the air inlet 3 are lowered to their lowest positions, on the X-axis, the width of the first part 521 of the second flow channel 52 is greater than the width of the second part 522. The flow channel width W2 of the first part 521 and the flow channel width W1 of the second part 522 satisfy: 1.1W1≤W2≤4W1. In this embodiment, both the first part 521 and the second part 522 are regular rectangular structures, meaning that W1 and W2 remain unchanged in their respective height directions. If they were irregular structures, then at any position in the height direction, the following condition must also be met: 1.1W1≤W2≤4W1.

[0044] To increase the abrupt change in the flow channel width W2 of the first part 521 and the flow channel width W1 of the second part 522, and to ensure the buffering, stabilizing, noise reduction, and oil interception effects of the abrupt change in the variable cross-section channel on the airflow, when the lower housing and the air inlet are both at their lowest positions, the flow channel widths W2 of the first part and W1 of the second part satisfy the following condition on the X-axis: 2W1≤W2≤3W1. Similarly, both the first part 521 and the second part 522 are regular rectangular structures, meaning that W1 and W2 remain unchanged in their respective height directions. If they are irregular structures, then at any position in the height direction, the condition 2W1≤W2≤3W1 must also be satisfied.

[0045] With the aforementioned variable cross-section air inlet channel, viewed from section M, the fumes enter the first section 521 through the narrow second part 522, and then into the upper casing 1. Because the second part 522 has a narrower front-to-back width, the fumes flow velocity is faster, which can drive the external flow field to achieve faster airflow, giving 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 uneven fumes flow velocity at the air inlet, affecting the fume extraction effect. The wide first part 521 is located downstream of the second part 522. At this time, the first part 521, due to its larger volume, can construct an efficient pressure stabilizing chamber, allowing the airflow to be buffered and stabilized within the pressure stabilizing chamber, ensuring that there is a basically the same wind speed at the air inlet, 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, and the problem of oil splashing and drifting is difficult to deal with, especially when there is a lot of condensed oil inside the fan 4. The wide first part 521 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.

[0046] Furthermore, the variable cross-section air inlet channel can effectively block the direct transmission of noise from the fan 4. By simulating the principle of reactive noise cancellation, the sound waves emitted from the fan 4 are reflected multiple times within the wide first section 521 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 chamber 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.

[0047] In this embodiment, when the angle between the oil guide plate 7 and the baffle 6 reaches 90°, the turning angle of the variable cross-section is the largest. This generates many small turbulences, increasing the contact between the oil fumes and the oil guide plate 7. As a result, the amount of condensed oil on the oil guide plate 7 increases, reducing the amount of oil fumes entering the fan 4, and thus reducing the amount of oil contamination on the impeller. In addition, turbulence is generated at the turning point. According to the oil fume path, the downstream of the turbulence is the large pressure stabilizing chamber, which corresponds to the first part of the second flow channel 52. The pressure stabilizing chamber has a certain height, so the airflow can be buffered and stabilized effectively, avoiding the influence of turbulence on the oil fume absorption effect.

[0048] like Figure 7 and Figure 8 As shown, the first part 521 is located in the third quadrant, and the second part 522 is at least partially located in the fourth quadrant. The first part 521 corresponds to the fourth flow channel 54. The vertical projection of the fourth flow channel 54 is completely located within the first part 521. In this way, on the one hand, the airflow in the first part 521 can flow smoothly into the fourth flow channel 54; on the other hand, it also facilitates the inclusion of the air inlet 3 into the second part 522 when it is raised, making full use of the internal space of the smoke hood and reducing the overall height of the machine.

[0049] The first flow channel 51, the rear flow channel of the second flow channel 52 and the third flow channel 53 communicate with each other from bottom to top in the vertical direction. At least 75% of the second portion 522 is located in the fourth quadrant along the X-axis direction. In this way, a direct suction and direct discharge passage is formed between the second portion 522 of the second flow channel 52 and the third flow channel 53, which facilitates rapid fume exhaust and improves the fume suction effect.

[0050] The flow channel width of the fourth flow channel 54 in the second quadrant is smaller than the flow channel width of the third flow channel 53 in the first quadrant. In this way, the flow channel at the main air inlet side of the fan 4 is relatively wide, and the flow channel at the auxiliary air inlet side is relatively narrow, so that the air flow distribution is more reasonable, which is beneficial to improving the fume suction effect.

[0051] When both the lower box body 2 and the air inlet body 3 are lowered to the lowest position, the entire fan 4 is located above the second flow channel 52. Such arrangement enables the lower box body 2 to have a sufficiently large descending stroke, and the negative pressure zone can move downward by a sufficient distance, thereby improving the fume suction effect. Assuming that the height of the fan 4 is L1, and the height from the bottommost end of the air inlet 31 of the air inlet body 3 to the horizontal plane where the bottommost end of the fan 4 is located is L2, the following condition is satisfied: L2≥bL1, wherein b is 1.3, 1.4, 1.5 or 1.6. In this way, the minimum descending stroke of the whole machine can be limited, so that the negative pressure zone can descend by a sufficient distance.

[0052] As Figure 3 shown, when the lower box body 2 and the air inlet body 3 are raised to the highest position, at least part of the fan 4 extends into the second flow channel 52. On the Y-axis, at least 50% of the fan 4 is located in the second flow channel 52, and at least 95% of the air inlet body 3 is located in the second flow channel 52. Assuming that the height of the air inlet body 3 located inside the lower box body 2 is H1, the height of the upper box body 1 located inside the lower box body 2 is H2, and the height of the lower box body 2 is H3, the following condition is satisfied: H1+H2≥aH3, wherein a is 0.8, 0.85, 0.9 or 0.95. Therefore, in the non-working state, the internal space of the lower box body 2 can be fully utilized to accommodate the upper box body 1 and the air inlet body 3, so as to reduce the height of the whole machine as much as possible. In addition, the condition H1+H2<H3 also needs to be satisfied. In this way, in the non-working state, there is no overlapping portion between the air inlet body 3 and the fan 4 in the vertical direction, which facilitates the oil liquid on the fan 4 to be guided onto the air inlet body 3.

[0053] Directional terms such as "front", "rear", "upper", "lower", "left", "right", "side", "top" and "bottom" are used in the specification and claims of the present invention to describe various example structural parts and elements of the present invention, but these terms are used herein only for the purpose of convenient description, and are determined based on the example orientation shown in the accompanying drawings. Since the embodiments disclosed by the present invention can be arranged in different directions, these directional terms are only for description and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to be opposite or consistent with the direction of gravity.

[0054] 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), and the air inlet (3) is disposed on the lower housing (2) and can move up and down relative to the lower housing (2), wherein a fan (4) is installed inside the upper housing (1), the fan (4) is vertically arranged, and the fan (4) includes a volute (41), characterized in that: A rectangular coordinate system is established on the cross-section M of the range hood. This cross-section M passes through the bottom end of the volute (41) and is parallel to the side plate of the upper housing (1). An X-axis and a Y-axis are set on the cross-section M. The X-axis passes through the bottom end of the volute (41) and is parallel to the horizontal plane. The Y-axis passes through the bottom end of the rear cover plate (411) of the volute and is parallel to the back plate (11) of the upper housing. In section M, a first flow channel (51) is formed inside the air inlet (3), a second flow channel (52) is formed inside the lower housing (2), and a main air inlet (42) is located on the rear side of the fan (4). A third flow channel (53) is formed between the main air inlet (42) and the upper housing back plate (11). When both the lower housing (2) and the air inlet (3) are lowered to their lowest positions, the first flow channel (51) is at least partially located in the fourth quadrant of the rectangular coordinate system, and the second flow channel (52) is at least partially located in the fourth quadrant of the rectangular coordinate system. Within the fourth quadrant of the rectangular coordinate system, the third flow channel (53) is located within the first quadrant of the rectangular coordinate system; when both the lower housing (2) and the air inlet (3) rise to their highest positions, the first flow channel (51) is entirely located within the fourth quadrant of the rectangular coordinate system or within both the fourth and third quadrants of the rectangular coordinate system, a portion of the second flow channel (52) is located within the first quadrant of the rectangular coordinate system and a portion is located within the fourth quadrant, and the third flow channel (53) is located within the first quadrant of the rectangular coordinate system.

2. The lifting range hood according to claim 1, characterized in that: When both the lower housing (2) and the air inlet (3) are lowered to their lowest positions, at least 80% of the first flow channel (51) is located in the fourth quadrant in the X-axis direction.

3. The lifting range hood according to claim 1, characterized in that: When both the lower housing (2) and the air inlet (3) are lowered to their lowest positions, the first flow channel (51) is completely located in the fourth quadrant in the X-axis direction.

4. The lifting range hood according to claim 1, characterized in that: The fan (4) has an auxiliary air inlet (43) on the front side. In section M, a fourth flow channel (54) is formed between the auxiliary air inlet (43) and the front plate (12) of the upper box. The fourth flow channel (54) is located in the second quadrant of the rectangular coordinate system.

5. The lifting range hood according to claim 4, characterized in that: When both the lower housing (2) and the air inlet (3) are lowered to their lowest positions, the second flow channel (52) includes a first part (521) and a second part (522), the first part (521) being at least partially located in the third quadrant and the second part (522) being at least partially located in the fourth quadrant, the first part (521) corresponding to the fourth flow channel (54).

6. The lifting range hood according to claim 5, characterized in that: The vertical projection of the fourth flow channel (54) is entirely within the first part (521).

7. The lifting range hood according to claim 5, characterized in that: A baffle (6) is provided inside the lower housing (2), the baffle (6) is parallel to the back plate (21) of the lower housing, and a second part (522) is formed between the baffle (6) and the back plate (21) of the lower housing. When the lower housing (2) and the air inlet (3) are both lowered to the lowest position, at least 75% of the second part (522) is located in the fourth quadrant in the X-axis direction.

8. The lifting range hood according to claim 5, characterized in that: When both the lower housing (2) and the air inlet (3) are lowered to their lowest positions, on the X-axis, the width of the first part (521) of the second flow channel (52) is greater than the width of the second part (522).

9. The lifting range hood according to claim 8, characterized in that: When both the lower housing (2) and the air inlet (3) are lowered to their lowest positions, on the X-axis, the flow channel width W2 of the first part (521) and the flow channel width W1 of the second part (522) satisfy: 1.1W1≤W2≤4W1.

10. The lifting range hood according to claim 4, characterized in that: The width of the fourth flow channel (54) in the second quadrant is smaller than the width of the third flow channel (53) in the first quadrant.

11. The lifting range hood according to claim 1, characterized in that: The rear channels of the first flow channel (51), the second flow channel (52), and the third flow channel (53) are interconnected from bottom to top in the vertical direction.

12. The lifting range hood according to claim 1, characterized in that: With the lower housing (2) lowered to its lowest position, the fan (4) is positioned above the second flow channel (52).

13. The lifting range hood according to claim 1, characterized in that: With the lower housing (2) raised to its highest position, the fan (4) extends at least partially into the second flow channel (52).

14. The lifting range hood according to claim 13, characterized in that: With the lower housing (2) raised to its highest position, the height of the air inlet (3) inside the lower housing (2) is H1, the height of the upper housing (1) inside the lower housing (2) is H2, and the height of the lower housing (2) is H3, satisfying H1+H2≥aH3, where a is 0.8, 0.85, 0.9, or 0.

95.

15. The lifting range hood according to claim 14, characterized in that: With the lower housing (2) raised to its highest position, H1+H2 is satisfied. <H3。 16. The lifting range hood according to claim 14, characterized in that: With the lower housing (2) raised to its highest position, the fan (4) is located at least 50% within the second flow channel (52) on the Y-axis.

17. The lifting range hood according to claim 14, characterized in that: With the lower housing (2) raised to its highest position, at least 95% of the air intake (3) is located within the second flow channel (52) on the Y-axis.

18. The lifting range hood according to claim 1, characterized in that: With the lower housing (2) lowered to its lowest position, the height of the fan (4) is L1, the air inlet (3) is provided with an air inlet (31), and the height from the bottom of the air inlet (31) to the horizontal plane where the bottom of the fan (4) is located is L2, satisfying: L2≥bL1, where b is 1.3, 1.4, 1.5 or 1.6.

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