Volute-less air box and tabletop range hood

Abstract

This application relates to the technical field of small oil fume extraction equipment, and particularly to a volute-less air box and a tabletop range hood. The volute-less air box is used for a tabletop range hood, and the volute-less air box includes a volute-less box body and an impeller disposed in the volute-less box body; the impeller has an air inlet end and an air outlet end, the volute-less box body is provided with an air inlet and an air outlet, the air inlet faces the air inlet end, and the air outlet faces the air outlet end. The tabletop range hood includes the volute-less air box. The volute-less air box and the tabletop range hood can eliminate the abnormal noise generated when the blades of the impeller pass through the volute tongue, reduce the noise peak value, improve the sound quality, and further reduce the operating noise of the tabletop range hood using the volute-less air box on the premise of achieving the same air box effect as the traditional volute.

Description

Technical Field

[0001] The present application relates to the technical field of small oil fume extraction equipment, and in particular to a volute-less air box and a tabletop range hood. Background Art

[0002] When cooking such as barbecuing or having hot pot on the dining table, it is very easy to leave a strong smell on the diners' clothes, and a large amount of steam and smoke generated during the cooking process also greatly affects the dining experience. In order to adsorb oil fume in time during the above cooking process, so as to purify the space and then improve the dining quality, the tabletop range hood came into being.

[0003] The tabletop range hood is placed on the dining table. Therefore, its volume should not be too large. In order to achieve the purpose of adsorbing oil fume and purifying the air, a certain air volume must be provided.

[0004] In view of its limited volume, if the traditional volute 30 is used, the distance between the outer edge 31 of the blade and the volute tongue 32 of the volute 30 will be too close, which will cause the blade passing frequency (BPF) noise to be too large during the operation of the fan, and then lead to problems such as abnormal noise and too large total noise value. Summary of the Invention

[0005] The purpose of the present application is to provide a volute-less air box and a tabletop range hood to solve, to a certain extent, the technical problem of excessive noise of the tabletop range hood in the prior art.

[0006] The present application provides a volute-less air box for a tabletop range hood. The volute-less air box includes a volute-less box body and an impeller disposed in the volute-less box body;

[0007] The impeller has an air inlet end and an air outlet end. The volute-less box body is provided with an air inlet and an air outlet. The air inlet faces the air inlet end, and the air outlet faces the air outlet end.

[0008] In the above technical solution, further, the air inlet is circular and coaxially arranged with the impeller. The diameter of the air inlet is the first diameter, and the diameter of the air inlet end of the impeller is the second diameter. The first diameter is greater than the second diameter.

[0009] In any of the above technical solutions, further, the volute-less air box further includes an annular flow guiding portion. The two axial ends of the annular flow guiding portion are respectively a first end and a second end. The first end surrounds the air inlet and is connected to the volute-less box body, and the second end is sleeved outside the air inlet end.

[0010] In any of the above technical solutions, further, the difference between the first diameter and the second diameter is 2-6 mm;

[0011] The insertion distance of the first end relative to the air inlet end is 1-3 mm.

[0012] In any of the above technical solutions, further, along the axial direction of the annular drainage part, the flow-through cross-section of the annular drainage part gradually increases from the second end to the first end.

[0013] In any of the above technical solutions, further, the axial profile of the annular drainage part is linear and forms a first predetermined angle with the axis of the annular drainage part;

[0014] The first predetermined angle is 30-60°.

[0015] In any of the above technical solutions, further, the axial profile of the annular drainage part is arc-shaped, and the arc bulges towards the inner side of the annular drainage part.

[0016] In any of the above technical solutions, further, the axial profile of the annular drainage part is circular arc-shaped;

[0017] Both ends of the annular drainage part are tangent to the side wall at the air inlet and the air inlet end respectively;

[0018] Or, the tangent line of the second end of the annular drainage part forms an inclination angle of 30-60° with the axis of the annular drainage part.

[0019] In any of the above technical solutions, further, the axial profile of the annular drainage part is quadratic curve-shaped;

[0020] Taking the second end of the axial profile of the annular drainage part as the origin, establish an x 1 -y 1 coordinate system, the y 1 axis is parallel to the radial direction of the annular drainage part, the x 1 axis is parallel to the axial direction of the annular drainage part 22, and the curve equation of the axial profile of the annular drainage part in the x 1 -y 1 coordinate system is y 1 =k 1 x 1 2 +2k 1 nx 1 , where k 1 is greater than 0 and not greater than 1 / 6, and n is not less than -7 and not greater than -1.

[0021] In any of the above technical solutions, further, the outer diameter of the air outlet end of the impeller is the third diameter;

[0022] The length of the volute - less casing is 1.2 - 2.2 times the third diameter;

[0023] The height of the volute - less casing is 1.6 - 2.8 times the third diameter;

[0024] The width of the volute - less casing is 0.5 - 1.5 times the third diameter.

[0025] In any of the above - mentioned technical solutions, further, the volute - less casing includes a front plate and a rear plate which are arranged at intervals along its length direction, the air inlet is opened on the front plate, and the minimum distance between the air outlet end and the rear plate is 0.1 - 0.3 times the width of the volute - less casing;

[0026] The volute - less casing includes two side plates which are arranged at intervals along its width direction, and the minimum distance between the circumferential side wall of the impeller and each of the two side plates is 0.1 - 0.3 times the third diameter;

[0027] The volute - less casing includes a top plate and a bottom plate which are arranged at intervals along its height direction, and the minimum distance between the top plate and the circumferential side wall of the impeller is 0.5 - 0.7 times the third diameter.

[0028] In any of the above - mentioned technical solutions, further, the profile line of the bottom plate in the length direction is in an arc shape protruding in the direction away from the top plate.

[0029] In any of the above - mentioned technical solutions, further, the profile line of the bottom plate in the length direction is in a circular - arc shape, and the bottom plate is coaxially arranged with the impeller;

[0030] The radius of the bottom plate is 0.5 - 0.9 times the third diameter.

[0031] In any of the above - mentioned technical solutions, further, the profile line of the bottom plate in the length direction is in a quadratic - curve shape;

[0032] Taking the axis of the impeller as the origin, establish an x 2 - y 2 coordinate system, the y 2 axis is parallel to the height direction of the volute - less casing, the x 2 axis is parallel to the width direction of the volute - less casing, and the curve equation of the profile line of the bottom plate in the x 2 - y 2 coordinate system is: y 2 = k 2 x 2 2 - 0.7D 3 where the third diameter is 0.7 - 2.8 times that of k 2 , and D 3 is the third diameter.

[0033] The present application also provides a tabletop range hood, which includes a housing and the volute-less air box described in any of the above technical solutions.

[0034] The volute-less air box is disposed inside the housing. A collection air inlet is formed in a side wall of the housing facing an air inlet of a volute-less box body of the volute-less air box, and an air discharge outlet is formed in a wall surface of the housing facing an air outlet of the volute-less box body of the volute-less air box.

[0035] Compared with the prior art, the beneficial effects of the present application are as follows:

[0036] The volute-less air box provided by the present application is used for a tabletop range hood. The volute-less air box includes a volute-less box body and an impeller disposed inside the volute-less box body. The impeller has an air inlet end and an air outlet end. The volute-less box body is provided with an air inlet and an air outlet, and the air inlet faces the air inlet end, and the air outlet faces the air outlet end.

[0037] On the one hand, since the volute-less box body is adopted, abnormal noise generated when the blades of the impeller pass through the volute tongue can be eliminated, the noise peak value can be reduced, the sound quality can be improved, and further the operation noise of the tabletop range hood using the volute-less air box can be reduced.

[0038] On the other hand, the volute-less air box is used for a tabletop range hood, which is an internal circulation range hood. After the oil fume is adsorbed and filtered by a built-in purification device thereof, the crystallized air is then discharged into the environment. Therefore, the requirement for the static pressure level inside the volute-less air box is not high, and selecting the volute-less box body can meet its static pressure requirement and achieve the same air box effect as that of a traditional volute.

[0039] It should be emphasized that through experiments, it is proved that the volute-less air box can reduce the noise by at least 2 decibels on the premise of the same air volume.

[0040] The range hood provided by the present application includes the above-mentioned volute-less air box, and thus can achieve all the beneficial effects of the volute-less air box. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0042] Figure 1 It is a schematic structural diagram of an air box in the prior art;

[0043] Figure 2 The first structural schematic diagram of the desktop range hood provided in the second embodiment of the present application;

[0044] Figure 3 The second structural schematic diagram of the desktop range hood provided in the second embodiment of the present application;

[0045] Figure 4 It is Figure 3 The first cross-sectional view at the H-H section;

[0046] Figure 5 It is Figure 4 The partial enlarged view at A;

[0047] Figure 6 It is Figure 3 The second cross-sectional view at the H-H section;

[0048] Figure 7 It is Figure 6 The partial enlarged view at B;

[0049] Figure 8 It is Figure 3 The third cross-sectional view at the H-H section;

[0050] Figure 9 It is Figure 8 The partial enlarged view at C;

[0051] Figure 10 It is Figure 3 The fourth cross-sectional view at the H-H section;

[0052] Figure 11 It is Figure 10 The partial enlarged view at D;

[0053] Figure 12 The third structural schematic diagram of the desktop range hood provided in the second embodiment of the present application;

[0054] Figure 13 The fourth structural schematic diagram of the desktop range hood provided in the second embodiment of the present application.

[0055] Reference numerals:

[0056] 1 - Desktop range hood; 10 - Housing; 100 - Back panel; 101 - Front panel; 11 - First grille; 12 - Second grille; 13 - Filter member; 14 - Motor; 2 - Volumeless air box; 20 - Volumeless box body; 200 - Top plate; 201 - Bottom plate; 202 - Left side plate; 203 - Right side plate; 204 - Front plate; 205 - Rear plate; 206 - Air inlet; 207 - Air outlet; 21 - Impeller; 210 - Air inlet end; 211 - Air outlet end; 22 - Annular flow guiding part. Detailed implementation manners

[0057] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0058] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0059] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0060] Embodiment 1

[0061] See Figures 1 to 13 As shown, an embodiment of the present application provides a volute-less air box 2 for a tabletop range hood 1. The volute-less air box 2 includes a volute-less box body 20 and an impeller 21 disposed in the volute-less box body 20, so that the impeller 21 can rotate in the volute-less box body 20.

[0062] The impeller 21 has an air inlet end 210 and an air outlet end 211. The volute-less box body 20 is provided with an air inlet 206 and an air outlet 207. The air inlet 206 faces the air inlet end 210, and the air outlet 207 faces the air outlet end 211.

[0063] Thus, when the impeller 21 operates, the air inlet end 210 of the impeller 21 sucks in oil fume towards the air inlet 206, and under the action of the operation and work done by the impeller 21, the air outlet end 211 of the impeller 21 discharges the oil fume out of the volute-less box body 20 through the air outlet 207.

[0064] In this embodiment, the air inlet 206 is circular and coaxially arranged with the impeller 21, and the diameter of the air inlet 206 is the first diameter D1 The diameter of the air inlet end 210 of the impeller 21 is the second diameter D. 2 The first diameter D 1 is greater than the second diameter D 2 so that the entire air inlet end 210 of the impeller 21 can face the wind, reducing the intake resistance, and further achieving efficient suction of lampblack.

[0065] In an alternative embodiment of the present embodiment, the volute-less air box 2 further includes an annular drainage portion 22. The two axial ends of the annular drainage portion 22 are respectively a first end and a second end. Specifically, the axis of the annular drainage portion 22 is coaxially arranged with the axis of the impeller 21.

[0066] The first end surrounds the air inlet 206 and is connected to the volute-less box body 20. The second end is sleeved on the air inlet end 210. Thus, on the one hand, the annular drainage portion 22 can provide a guide for the lampblack in the external environment to flow towards the air inlet end 210 of the impeller 21. On the other hand, it can prevent the lampblack from leaking through the gap between the air inlet 206 and the air inlet end 210, improving the air intake volume of the impeller 21, and further improving the air discharge volume of the volute-less air box 2. Further, it can also prevent the lampblack from re-entering the air inlet end 210 of the impeller 21 and prevent the formation of vortices of the lampblack at the air inlet end 210, thereby improving the air intake efficiency and reducing the wind resistance.

[0067] In this embodiment, in order to effectively prevent the lampblack from escaping, the difference between the first diameter D 1 and the second diameter D 2 is 2 - 6 mm, such as 2 mm, 3 mm, 4 mm, 5 mm or 6 mm.

[0068] The insertion distance L of the first end relative to the air inlet end 210 is 1 - 3 mm, such as 1 mm, 2 mm or 3 mm, especially 1.5 mm.

[0069] In this embodiment, along the axis of the annular drainage portion 22, the flow-through cross-section of the annular drainage portion 22 gradually increases from the second end to the first end, so as to improve the lampblack suction effect of the impeller 21 through negative pressure expansion.

[0070] Optionally, the axial length of the annular drainage portion 22 is 9 mm - 15 mm, such as 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm or 15 mm, especially 12 mm.

[0071] In this embodiment, as an example of making the annular drainage portion 22 expand outward under negative pressure, the axial profile of the annular drainage portion 22 can be, for example, an arc or a straight line. The axial profile refers to the shape of the wall surface of the annular drainage portion 22 after being cut in any axial section of the annular drainage portion 22. The arc can be any curve convex toward the inner side of the annular drainage portion 22, as long as it can ensure that the flow cross section of the annular drainage portion 22 gradually increases from the second end to the first end, and it is not necessarily an arc.

[0072] Specifically, if Figure 6 and Figure 7 As shown, when the axial profile of the annular guide portion 22 is in a straight line, a first predetermined angle a is formed between the annular guide portion 22 and the axis, and the first predetermined angle a is 30-60°. For example, the first predetermined angle a is 30°, 40°, 50° or 60°.

[0073] When the axial profile of the annular drainage portion 22 is in an arc shape, for example, it is an arc shape or a quadratic curve.

[0074] Among them, Figure 4 and Figure 5 As shown, when the axial profile of the annular guide portion 22 is in an arc shape, the two ends of the annular guide portion 22 are respectively tangent to the side wall at the air inlet 206 and the air inlet end 210, or the tangent line of the second end of the annular guide portion 22 forms an inclination angle b of 30-60° with the axis of the annular guide portion 22.

[0075] Optionally, the arc radius of the axial profile of the annular drainage portion 22 is 5 mm.

[0076] like Figure 8 and Figure 9 As shown, when the axial profile of the annular drainage portion 22 is in the shape of a quadratic curve, the second end of the axial profile of the annular drainage portion 22 is taken as the origin to establish x 1 -y 1 Coordinate system, y 1 The axis is parallel to the radial direction of the annular drainage part, x 1 The axis is parallel to the axial direction of the annular drainage portion 22, and the curve equation of the axial profile of the annular drainage portion 22 is y 1 =k 1 x 1 2 +2k 1 nx 1 , where k 1 is greater than 0 and not greater than 1 / 6, n is not less than -7 and not greater than -1.

[0077] Specifically, by 1Reasonably limit m and n so that the twisted shape of the annular drainage part 22 is within a reasonable range, which is convenient for processing and forming, does not cause spatial interference with the air inlet end 210 of the impeller, enables reliable docking between the two, and does not generate noise due to diversion.

[0078] In an alternative solution of this embodiment, the outer diameter of the air outlet end 211 of the impeller 21 is the third diameter D 3 , that is, the outer diameter of the blades of the impeller 21 is the third diameter D 3 .

[0079] The length S1 of the volute-less housing 20 is 1.2 - 2.2 times the third diameter D 3 , such as 1.2 times, 1.5 times, 1.8 times, 2 times or 2.2 times.

[0080] The height S3 of the volute-less housing 20 is 1.6 - 2.8 times the third diameter D 3 , such as 1.6 times, 2 times, 2.5 times or 2.8 times.

[0081] The width S2 of the volute-less housing 20 is 0.5 - 1.5 times the third diameter D 3 , such as 0.5 times, 0.8 times, 1 times, 1.3 times or 1.5 times.

[0082] By limiting the length, width and height of the volute-less housing 20, the size of the volute-less housing 20 is matched with the size of the impeller 21, which is beneficial to improving the suction effect, reducing noise, reducing wind resistance and meeting the demand of air discharge volume.

[0083] In this embodiment, the volute-less housing 20 includes a front plate 204 and a rear plate 205 arranged at intervals along its own length direction, and the air inlet 206 is opened on the front plate 204. In order to control the blade passing frequency noise between the impeller 21 and the front plate 204 or the rear plate 205 within a reasonable range, the minimum distance S10 between the air outlet end 211 and the rear plate 205 is 0.1 - 0.3 times the width of the volute-less housing 20, such as 0.1 times, 0.2 times or 0.3 times.

[0084] In this embodiment, the volute-less housing 20 includes two side plates arranged at intervals along its own width direction, namely a left side plate 202 and a right side plate 203. In order to control the blade passing frequency noise between the impeller 21 and the left side plate 202 or the right side plate 203 within a reasonable range, the minimum distance S20 between the circumferential side wall of the impeller 21 and the left side plate 202 and the minimum distance S21 between the circumferential side wall of the impeller 21 and the right side plate 203 are respectively 0.1 - 0.3 times the third diameter D 3 , such as 0.1 times, 0.2 times or 0.3 times.

[0085] Optionally, as Figure 12As shown, the left side plate 202 and the right side plate 203 can be symmetrically arranged with respect to the impeller 21, that is, the minimum distances S20 and S21 are equal; or Figure 13 As shown, the impeller 21 is arranged closer to the left side plate 202, that is, S20 is smaller than S21; or, the impeller 21 is arranged closer to the right side plate 203, that is, S20 is larger than S21 (not shown in the figure).

[0086] In this embodiment, the volute-free housing 20 includes a top plate 200 and a bottom plate 201 spaced apart along its height direction. In order to control the blade passing frequency noise between the impeller 21 and the top plate 200 within a reasonable range, the minimum distance S30 between the top plate 200 and the circumferential side wall of the impeller 21 is the third diameter D 3 In order to control the blade passing frequency noise between the impeller 21 and the bottom plate 201 within a reasonable range, the minimum distance S31 between the bottom plate 201 and the circumferential side wall of the impeller 21 is 0.5-0.7 times, for example, 0.5 times, 0.6 times or 0.7 times. 3 0.3-0.5 times, for example, 0.3 times, 0.4 times or 0.5 times.

[0087] In this embodiment, when the oil smoke flows along the square cavity under the action of suction, a vortex will appear at the right-angled corner position, and the bottom plate 201 is subjected to arc transition treatment. Specifically, the length direction profile of the bottom plate 201 is an arc convex in the direction away from the top plate 200, which can make the airflow transition smooth, effectively suppress the formation of vortices, and reduce the intensity of vortices. Among them, the length direction profile refers to the shape of the bottom plate 201 in the cross-sectional plane when the cross-sectional plane is perpendicular to the length direction of the volute-free housing 20. The arc can be any curve convex in the direction away from the top plate 200, as long as it can ensure that the airflow does not make a sharp turn but a smooth transition, and it is not necessarily a circular arc.

[0088] In this embodiment, as an example in which the longitudinal profile of the bottom plate 201 is an arc shape that is convex in a direction away from the top plate 200, the longitudinal profile of the bottom plate 201 is an arc shape or a quadratic curve shape.

[0089] Among them, Figure 3 As shown, when the longitudinal profile of the bottom plate 201 is in an arc shape, the bottom plate 201 and the impeller 21 are coaxially arranged; the radius of the bottom plate 201 is the third diameter D 3 0.5-0.9 times, for example 0.7 times.

[0090] In this embodiment, Figure 12 As shown, when the longitudinal profile of the bottom plate 201 is a quadratic curve, the axis of the impeller 21 is taken as the origin and the x 2 -y 2Coordinate system, y 2 The axis is parallel to the height direction of the volute-less housing, and the x 2 axis is parallel to the width direction of the volute-less housing. The curve equation of the curve of the length direction of the bottom plate 201 is: y 2 = k 2 x 2 2 -0.7D 3 The third diameter D 3 is 0.7 - 2.8 times that of k 2 For example, 0.7 times, 1 time, 1.5 times, 2 times or 2.8 times.

[0091] Embodiment 2

[0092] Embodiment 2 provides a tabletop range hood 1. This embodiment includes a housing 10 and the volute-less air box 2 in Embodiment 1. The technical features of the volute-less air box 2 disclosed in Embodiment 1 are also applicable to this embodiment, and the technical features of the volute-less air box 2 already disclosed in Embodiment 1 will not be described repeatedly.

[0093] The volute-less air box 2 is arranged inside the housing 10. A collection air inlet is provided on the side wall of the housing 10 facing the air inlet 206 of the volute-less housing 20 of the volute-less air box 2, and an exhaust air outlet is provided on the wall surface of the housing 10 facing the air outlet 207 of the volute-less housing 20 of the volute-less air box 2.

[0094] Optionally, the side wall of the housing 10 provided with the collection air inlet is the panel 101 of the housing 10. A treatment space is formed between the panel 101 and the front plate 204 of the volute-less air box 2. A filtering member 13 is arranged in the treatment space so that under the suction of the impeller 21, the oil fume enters the treatment space through the collection air inlet, and after being filtered and purified by the filtering member 13 in the treatment space, it then enters the air inlet end 210 of the impeller 21 through the air inlet 206.

[0095] Optionally, the collection air inlet is provided in the upper half of the panel 101, so as to be able to efficiently suck the oil fume escaping upwards. In this case, the air inlet area of the air inlet 206 is mainly concentrated in its upper half, and the panel 101 is directly in front of the lower half of the impeller 21. Therefore, the main work area of the impeller 21 is distributed in its upper half, that is, the part close to the air outlet 207. In view of this, most of the oil fume enters the impeller 21 through the air inlet 206 and is then thrown out from the upper half of the impeller 21 and directly discharged into the atmosphere through the air outlet 207. Only a very small part of the oil fume rotates with the impeller 21 and is thrown into the interior of the volute-less housing 20 at other positions. This part of the oil fume has a tangential velocity rotating with the impeller 21 and is guided by the arc-shaped bottom plate 201 to move towards the outlet and be discharged.

[0096] Optionally, the housing 10 further includes a back plate 100, and the impeller 21 is disposed between the back plate 100 and the front panel 101.

[0097] Optionally, to simplify the structure, the back plate 100 of the housing 10 and the rear plate 205 of the volute-less air box 2 are formed by one plate member, and the top of the housing 10 and the top plate 200 of the volute-less air box 2 are formed by one plate member, so that the air discharge port and the air outlet 207 are realized through the same air port.

[0098] Optionally, the air inlet is provided with a first grille 11, and the air outlet is provided with a second grille 12.

[0099] Optionally, the tabletop range hood further includes a motor 14 disposed inside the housing 10 to drive the impeller 21 through the motor 14.

[0100] The tabletop range hood in this embodiment has the advantages of the volute-less air box in the first embodiment, and the advantages of the volute-less air box disclosed in the first embodiment will not be repeated here.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention. In addition, those skilled in the art can understand that although some embodiments described herein include some features included in other embodiments but not other features, the combination of the features of different embodiments means that it is within the scope of the present invention and forms different embodiments. For example, any one of the claimed embodiments can be used in any combination. The information disclosed in this background art section is only intended to deepen the understanding of the overall background art of the present invention, and should not be regarded as an admission or any form of suggestion that this information constitutes the prior art known to those skilled in the art.

Claims

1. A volute-less air box (2), characterized in that, it is used for a tabletop range hood (1), and the volute-less air box (2) includes a volute-less box body (20) and an impeller (21) arranged in the volute-less box body (20); the impeller (21) has an air inlet end (210) and an air outlet end (211), the volute-less box body (20) is provided with an air inlet (206) and an air outlet (207), the air inlet (206) faces the air inlet end (210), and the air outlet (207) faces the air outlet end (211); the air inlet (206) is circular and arranged coaxially with the impeller (21), the diameter of the air inlet (206) is the first diameter, the diameter of the air inlet end (210) of the impeller (21) is the second diameter, and the first diameter is greater than the second diameter; it further includes an annular flow guiding part (22), the two axial ends of the annular flow guiding part (22) are respectively a first end and a second end, the first end surrounds the air inlet (206) and is connected to the volute-less box body (20), and the second end is sleeved outside the air inlet end (210); the difference between the first diameter and the second diameter is 2 - 6 mm; the insertion distance of the first end relative to the air inlet end (210) is 1 - 3 mm; along the axis of the annular flow guiding part (22), the flow-through cross-section of the annular flow guiding part (22) gradually increases from the second end to the first end.

2. The volute-less air box (2) according to claim 1, characterized in that, the axial profile of the annular flow guiding part (22) is linear and forms a first predetermined angle with the axis of the annular flow guiding part (22); the first predetermined angle is 30 - 60°.

3. The volute-less air box (2) according to claim 1, characterized in that, the axial profile of the annular flow guiding part (22) is arc-shaped, and the arc bulges towards the inside of the annular flow guiding part (22).

4. The volute-less air box (2) according to claim 3, characterized in that, the axial profile of the annular flow guiding part (22) is circular arc-shaped; the two ends of the annular flow guiding part (22) are respectively tangent to the side wall at the air inlet (206) and the air inlet end (210); alternatively, the tangent line of the second end of the annular flow guiding part (22) forms an inclination angle of 30 - 60° with the axis of the annular flow guiding part (22).

5. The volute-less air box (2) according to claim 3, characterized in that, the axial profile of the annular flow guiding part (22) is quadratic curve-shaped; Taking the second end of the axial profile of the annular drainage part (22) as the origin, establish an x 1 -y 1 coordinate system, where the y 1 axis is parallel to the radial direction of the annular drainage part, and the x 1 axis is parallel to the axial direction of the annular drainage part (22). The curve equation of the axial profile of the annular drainage part (22) in the x 1 -y 1 coordinate system is y 1 = k 1 x 1 2 + 2k 1 nx 1 , where k 1 is greater than 0 and not greater than 1 / 6, and n is not less than -7 and not greater than -1.

6. The volute-less air box (2) according to claim 2, characterized in that, the outer diameter of the air outlet end (211) of the impeller (21) is the third diameter; the length of the volute-less box body (20) is 1.2 - 2.2 times the third diameter; the height of the volute-less box body (20) is 1.6 - 2.8 times the third diameter; the width of the volute-less box body (20) is 0.5 - 1.5 times the third diameter.

7. The volute-less air box (2) according to claim 6, characterized in that, The volute-less casing (20) includes a front plate (204) and a rear plate (205) that are spaced apart along the length direction of the casing itself. The air inlet (206) is formed in the front plate (204), and the minimum distance between the air outlet end (211) and the rear plate (205) is 0.1 - 0.3 times the width of the volute-less casing (20). The volute-less casing (20) includes two side plates that are spaced apart along the width direction of the casing itself. The minimum distances between the circumferential side walls of the impeller (21) and the two side plates are 0.1 - 0.3 times the third diameter. The volute-less casing (20) includes a top plate (200) and a bottom plate (201) that are spaced apart along the height direction of the casing itself. The minimum distance between the top plate (200) and the circumferential side wall of the impeller (21) is 0.3 - 0.5 times the third diameter.

8. The volute-less air box (2) according to claim 7, wherein, the profile curve of the bottom plate (201) in the length direction is an arc protruding in a direction away from the top plate (200).

9. The volute-less air box (2) according to claim 8, wherein, the profile curve of the bottom plate (201) in the length direction is circular arc-shaped, and the bottom plate (201) is coaxially arranged with the impeller (21); the radius of the bottom plate (201) is 0.5 - 0.9 times the third diameter.

10. The volute-less air box (2) according to claim 8, wherein, the profile curve of the bottom plate (201) in the length direction is quadratic curve-shaped; Taking the axis of the impeller (21) as the origin, an x 2 -y 2 coordinate system is established, the y 2 axis is parallel to the height direction of the volute-less casing, the x 2 axis is parallel to the width direction of the volute-less casing, and the curve equation of the length direction profile of the bottom plate (201) in the x 2 -y 2 coordinate system is: y 2 = k 2 x 2 2 -0.7D 3 , where the third diameter is 0.7 - 2.8 times that of k 2 , and D 3 is the third diameter.

11. A tabletop range hood (1), wherein, the tabletop range hood (1) includes a housing (10) and the volute-less air box (2) according to any one of claims 1 to 10; the volute-less air box (2) is arranged in the housing (10). A collection air port is formed in the side wall of the housing (10) facing the air inlet (206) of the volute-less casing (20) of the volute-less air box (2), and an exhaust air port is formed in the wall surface of the housing (10) facing the air outlet (207) of the volute-less casing (20) of the volute-less air box (2).

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