Volute assembly of centrifugal fan, centrifugal fan and range hood

Abstract

The utility model discloses a volute assembly of centrifugal fan, centrifugal fan and range hood, the volute assembly of centrifugal fan comprises two cover plates that are arranged at interval, an annular wall is arranged between the two cover plates, the annular wall comprises a volute tongue; the annular wall further comprises a molded line adjusting assembly, the molded line adjusting assembly comprises a fixing shaft and an annular wall body capable of deforming, the fixing shaft is parallel to the axis of the centrifugal fan and is adjacent to the volute tongue in the circumferential direction, and the two ends of the fixing shaft are fixed to the cover plates at the corresponding positions respectively. The part of the ring wall main body is wound on the fixed shaft and is kept tensioned; the volute assembly further comprises a movement mechanism used for driving the annular wall body to move so as to change the molded line of the annular wall, the movement mechanism comprises a cam which is arranged on the outer side of the annular wall and can rotate relative to the annular wall, the rotating axis of the cam is parallel to the extending direction of the fixing shaft, and the annular wall body keeps the tendency of being tightly attached to the cam.

Description

TECHNICAL FIELD

[0001] The utility model relates to power device especially a volute assembly of centrifugal fan, centrifugal fan of application has this volute assembly and range hood of application has this centrifugal fan. BACKGROUND

[0002] According to GBT 17713-2022 "range hood and other cooking fume suction and exhaust device", the main noise evaluation index of range hood includes half anechoic chamber noise and working noise.These parameters as nominal index are important basis for user to compare product performance directly, and noise also directly influences user's use experience.Therefore, how to reduce the half anechoic chamber noise and working noise of range hood is crucial.

[0003] Fan system is the main structure that influences range hood noise, in many methods of reducing range hood noise, it is a common means to design reasonable volute profile, and the flow is improved through the optimization of volute profile to reduce vortex noise, such as the volute profile improvement disclosed in Chinese patents with application numbers 201110118687.5, 201710798758.8.

[0004] However, the volute profile design of the current volute, the lowest noise in half anechoic chamber working condition, and the lowest noise in working noise working condition, are not consistent.I.e.sometimes the volute profile has lower noise in half anechoic chamber noise working condition, but its working noise is higher, and vice versa.

[0005] Therefore, the volute profile currently applied in products usually needs to consider the half anechoic chamber noise and working noise index, and has to be compromised, and cannot meet simultaneously.Therefore, it still needs to be further improved. INVENTION CONTENTS

[0006] The first technical problem to be solved by the utility model is to provide a volute assembly of centrifugal fan, which can be adjusted in real time to meet lower half anechoic chamber noise and working noise, aiming at the deficiencies of the prior art.

[0007] The second technical problem to be solved by the utility model is to provide a centrifugal fan with the above volute assembly.

[0008] The third technical problem to be solved by the utility model is to provide a range hood with the above centrifugal fan.

[0009] The technical scheme adopted by the utility model to solve the above first technical problem is as follows: a volute assembly of centrifugal fan, comprising two cover plates arranged at intervals, a ring wall is arranged between the two cover plates, the ring wall comprises a volute tongue; characterized by:

[0010] The ring wall further comprises a camber adjusting assembly, which comprises a fixed shaft parallel to the axis of the centrifugal fan and arranged circumferentially adjacent to the volute tongue, and a deformable ring wall body, parts of which are wound on the fixed shaft and kept in tension;

[0011] The volute assembly further comprises a motion mechanism for driving the ring wall body to move and change the camber of the ring wall, which comprises a cam arranged outside the ring wall and capable of rotating relative to the ring wall, the rotation axis of the cam being parallel to the extension direction of the fixed shaft, and the ring wall body keeping a tendency to be in close contact with the cam.

[0012] By arranging the deformable ring wall body, the ring wall body can move outward under the action of the cam to increase the camber of the ring wall until the base circle radius of the spiral line of the camber reaches the maximum, at which time the camber of the ring wall reaches the maximum, and can also move inward under the action of the cam to decrease the camber of the ring wall until the base circle radius of the spiral line of the camber reaches the minimum, at which time the camber of the ring wall reaches the minimum, so that the camber can be changed according to the actual working condition, so that the noise of the half-muffling chamber and the working noise are lower; by winding parts of the ring wall body on the fixed shaft, the circumference can be changed when the camber is changed, so as to avoid the change of the position of the starting end, which leads to the increase of the gap adjacent to the volute tongue and the pressure relief, or the position of the cover plate at the air outlet of the volute is not flush and the pressure relief, so as to ensure the normal work of the centrifugal fan.

[0013] Further, in order to fix the relative positions of the two cover plates, the volute assembly further comprises a fastening piece arranged outside the ring wall body, the fastening piece being parallel to the extension direction of the fixed shaft, and the two ends of the fastening piece being fixed with the cover plates at the corresponding positions, and the cam being arranged on the fastening piece by rotating the cam shaft.

[0014] In order to make the ring wall body close to the cam, the motion mechanism further comprises an elastic member connected between the ring wall body and the fastening piece, so as to apply a force to the part of the ring wall body not wound on the fixed shaft to pull it outward.

[0015] Further, in order to make the rotation of the cam meet the deformation of the ring wall body to the required profile, the ring wall body can be in at least two positions to make the ring wall have a first profile and a second profile, the first profile is the profile meeting the lowest noise of the half-muffler, and the second profile is the profile meeting the lowest working noise; the end of the fastening piece is bent and welded with the corresponding cover plate, the bent part of the fastening piece has a welding positioning mark, on the line connecting the center of the welding positioning mark and the center of the cam shaft of the corresponding cam, the distance between the first profile and the second profile is L1, the distance between the center of the cam shaft and the profile located on the outer side is L2, the thickness of the ring wall body is b, the base circle radius of the cam is N1, the distance between the most protruding part of the cam and the center of the cam shaft is N2, and the following conditions are met: N1=L2-b; N2 should meet: N2=L1+L2-b.

[0016] Preferably, in order to avoid the interference between the fastening piece and the cover plate, on the line connecting the center of the welding positioning mark and the center of the cam shaft of the corresponding cam, the distance between the welding positioning mark and the profile located on the outer side is 5-30 mm.

[0017] Preferably, in order to avoid the interference between the cam shaft and the cover plate, a hole for connecting with the cam shaft is arranged on the fastening piece, on the line connecting the center of the welding positioning mark and the center of the cam shaft of the corresponding cam, the distance between the hole and the profile located on the outer side is 5-20 mm.

[0018] Preferably, the value of b ranges from 0.5 to 1 mm, so as to meet the sufficient strength and flexibility of deformation, thereby the position of the multiple control points of the ring wall can be controlled by the cam, and the special case that the optimal profiles of the volute in two working conditions intersect can be applied.

[0019] Further, the cam has at least two and is uniformly spaced along the circumference of the ring wall.

[0020] Further, in order to avoid the relaxation of the ring wall body when the profile of the ring wall is reduced to cause the shortening of the circumference, the profile adjusting assembly further comprises a clock spring, the end of the ring wall body is connected with the fixed shaft through the clock spring, so that when the ring wall body moves radially inward, the number of turns around the fixed shaft is increased to keep tension.

[0021] Further, in order to facilitate the definition of the relative position of the ring wall body and the cover plate in the height direction of the volute, and avoid the pressure relief caused by the unevenness, the end of the ring wall body away from the fixed shaft is formed with a flange, the flange is formed on the opposite sides of the ring wall body, each cover plate is formed with a limiting groove on the side facing the inside of the volute assembly, the limiting groove extends along the width direction of the volute assembly, and the flange is clamped into the limiting groove and can move linearly along the limiting groove.

[0022] To facilitate control of the outer steady position of the ring wall profile, the outer edge of each cover plate is further formed with a limiting flange, each limiting flange being formed by bending the edge of the cover plate towards the other cover plate.

[0023] The technical solution adopted by the utility model to solve the above-mentioned second technical problem is: a centrifugal fan, characterized in that: the volute assembly is applied.

[0024] The technical solution adopted by the utility model to solve the above-mentioned third technical problem is: a range hood, characterized in that: the centrifugal fan is applied.

[0025] Compared with the prior art, the utility model has the advantages that: through the setting of the deformable ring wall main body, the ring wall main body can be moved outward under the action of the cam to increase the ring wall profile, until the base circle radius of the spiral line of the profile reaches the maximum, at which time the ring wall profile reaches the longest, and the ring wall main body can also be moved inward under the action of the cam to reduce the ring wall profile, until the base circle radius of the spiral line of the profile reaches the minimum, at which time the ring wall profile reaches the shortest, so that the profile can be changed according to the actual working condition, so that the semi-anechoic chamber noise and the working noise are lower; through the winding of the ring wall main body part on the fixed shaft, the circumference can be changed accordingly when the profile is changed, so as to avoid the change of the starting end position, resulting in the increase of the gap adjacent to the volute tongue and the pressure relief, or the non-level position of the cover plate at the volute air outlet and the pressure relief, ensuring the normal working of the centrifugal fan. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic view of the volute assembly of the utility model embodiment;

[0027] Figure 2 It is a schematic view (different viewing angle) of the volute assembly of the utility model embodiment; Figure 1

[0028] Figure 3 It is a partial I enlarged schematic view of Figure 2

[0029] Figure 4 It is an exploded structural schematic view of the volute assembly of the utility model embodiment;

[0030] Figure 5 It is a partial II enlarged schematic view of Figure 4

[0031] Figure 6 It is a schematic view of the movement mechanism of the volute assembly of the utility model embodiment;

[0032] Figure 7 It is a sectional view (the innermost side state of the profile) of the volute assembly of the utility model embodiment; ​​​

[0033] Figure 8 is a partial III enlarged schematic view of the volute assembly; Figure 7

[0034] Figure 9 is a cross-sectional view of the volute assembly of the embodiment of the present application (the outermost state of the profile line);

[0035] Figure 10 is a partial IV enlarged schematic view of the volute assembly; Figure 9

[0036] Figure 11 is a partial schematic view of the fastening sheet and the ring wall profile line of the volute assembly of the embodiment of the present application;

[0037] Figure 12 is a partial schematic view of the cam and the ring wall body of the volute assembly of the embodiment of the present application. DETAILED DESCRIPTION

[0038] The embodiments of the present application will be described in detail below, examples of which are shown in the drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions.

[0039] In the description of the present application, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and since the embodiments disclosed by the present application can be arranged in different directions, these terms indicating the direction are only as an illustration and should not be regarded as a limitation, such as "upper", "lower" are not necessarily limited to the direction opposite or consistent with the direction of gravity. In addition, the features defined as "first", "second" can explicitly or implicitly include one or more of the features.

[0040] Referring to Figures 1-8 , a volute assembly of a centrifugal fan, which can be mainly used in a range hood, can also be used in other occasions requiring such a power device.

[0041] ​​The volute assembly comprises two cover plates 1 arranged at intervals, a ring wall is arranged between the two cover plates 1, the ring wall comprises a volute tongue 21 and a contour adjustment assembly, the contour adjustment assembly comprises a fixed shaft 221, a clock spring 222 and a ring wall body 223, the volute tongue 21 and the ring wall body 223 are independent of each other. The fixed shaft 221 is parallel to the axis of the centrifugal fan, and is arranged adjacent to the volute tongue 21 in the circumferential direction, and the two ends of the fixed shaft 221 are fixed with the cover plates 1 at the corresponding positions respectively. In order to facilitate the fixation of the fixed shaft 221, the outer side of each cover plate 1 extends outward to form a base 14, and the end of the fixed shaft 221 can be fixed with the base 14. The ring wall body 223 is partially arranged around the fixed shaft 221, and the partially arranged part is wound into a roll shape. The end of the ring wall body 223 is connected with the fixed shaft 221 through the clock spring 222. The volute tongue 21 and the unwound part of the ring wall body 223 constitute a conventional ring wall, and the contour of the combination of the two is the contour of the ring wall. By making the ring wall have a wound form, the problem of inconsistent circumference when the volute contour is changed can be solved. The ring wall body 223 is made of a deformable material, such as a metal sheet.

[0042] The volute assembly further comprises a fastening sheet 3 arranged on the outer side of the ring wall body 223, the fastening sheet 3 is parallel to the extension direction of the fixed shaft 221, and the two ends of the fastening sheet 3 are bent to be welded and fixed with the cover plates 1 at the corresponding positions, thereby realizing the fixation of the volute assembly. The electromagnet 225 is fixed on the side of the fastening sheet 3 facing the ring wall body 223.

[0043] The end of the ring wall body 223 away from the fixed shaft 221 is formed with flanges 224 on the opposite sides respectively, and each cover plate 1 is formed with a limiting groove 11 on the side facing the inside of the volute assembly, the limiting groove 11 extends along the width direction of the volute assembly, such as the left-right direction shown in Figure 6 The flanges 224 are clamped into the limiting grooves 11 and can move linearly along the limiting grooves 11, and through the cooperation of the flanges 224 and the limiting grooves 11, the activity of the ring wall body 223 is ensured, and at the same time, the relative position of the end of the ring wall body 223 with the cover plate 1 (basically flush) can be ensured, that is, the displacement of the end of the ring wall body 223 in the height direction of the volute assembly is avoided, the height direction being the up-down direction shown in Figure 6 .

[0044] The outer side edge of each cover plate 1 is formed with a limiting flange 13, and each limiting flange 13 is formed by bending the edge of the cover plate 1 towards the other cover plate 1. The limiting flange 13 limits the limit position (outer limit) of the radial outward expansion of the ring wall body 223. The position of the limiting flange 13 can be obtained based on design tests, and is designed for the contour with the lowest noise in the semi-anechoic chamber and the contour with the lowest working noise.

[0045] The volute assembly further comprises a movement mechanism for driving the ring wall body 223 to move, which comprises a cam 41 and an elastic member 42. The cam 41 can have at least two, which are uniformly arranged along the circumference of the ring wall, so that the ring wall body 223 has a plurality of controllable positions in the entire circumference. The number of the above-mentioned fastening pieces 3 is consistent with the cam 41, and the two ends of each cam 41 are rotatably connected to the end of the corresponding fastening piece 3 through a cam shaft 411, and the cam 41 can rotate relative to the ring wall, and the rotation axis of the cam 41 is parallel to the extension direction of the fixed shaft 221. The cam 41 can be driven to rotate by a rotating drive module (not shown) such as a motor. The elastic member 42 is connected between the ring wall body 223 and the fastening piece 3, and provides an outward traction force to the unwound part of the ring wall body 223, so that the cam 41 is tightly attached to the ring wall body 223 at the corresponding position. The elastic member 42 is preferably a spring.

[0046] In order to optimize the flow control of the centrifugal fan, so that when it is applied to the range hood, the two working condition noises of the range hood (i.e. the half-muffler working condition and the working noise chamber working condition) are further reduced. By controlling the rotation of the cam 41, it is switched to the profile line with the lowest half-muffler noise in the half-muffler working condition, and switched to the profile line with the lowest working noise in the working noise chamber working condition. As shown in Figure 7 and Figure 8 , at this time the volute profile line is in the minimum state, the ring wall body 223 is wound more (the excess part of the profile line caused by the inward movement will be wound on the fixed shaft 221 by the force of the clock spring 222, keeping tension), and the position where the cam 41 and the ring wall body 223 contact is farthest from the center of rotation of the cam 41 (the distance is N2 described below). As shown in Figure 9 and Figure 10 , at this time the volute profile line is in the maximum state, the ring wall body 223 is wound less, and the position where the cam 41 and the ring wall body 223 contact is closest to the center of rotation of the cam 41 (the distance is the base circle radius of the cam 41, i.e. N1 described below).

[0047] The logic for the above-mentioned volute assembly to achieve the function is as follows:

[0048] 1) Obtain the profile line with the lowest half-muffler noise (denoted as the first profile line A) and the profile line with the lowest working noise (denoted as the second profile line B) through testing;

[0049] 2) Based on the above-mentioned profile line parameters, design the limiting flange 13 on the cover plate 1 of the volute assembly (usually corresponding to the third profile line C), and take the first profile line A and the second profile line B on the outer side of the intersection. That is, assuming that the A and B profile lines intersect, then take each position of the A and B profile lines, and splice them into the third profile line C relative to the outer side of the volute center;

[0050] 3) Based on the profile lines A and B and the positions of the cam 41 and the fastening piece 3 relative to the ring wall of the volute, design the required cam profile line;

[0051] 4) Based on the type line A, B and the position of the cam 41 and the fastening piece 3 relative to the ring wall of the volute, select the required size of the elastic member to make the ring wall body 223 adhere to the cam 41 in each working condition;

[0052] 5) Record the speed range of the range hood in the working noise condition (recorded as n1), and record the approximate speed range of the range hood in the semi-anechoic chamber noise table (recorded as n2);

[0053] 6) When the actual speed n is detected within the n1 range during the actual operation of the range hood, the motor is controlled to apply power to rotate the cam 41, so that the volute type line switches to the second type line B with lower working noise; when the actual speed n is detected within the n2 range, the motor is controlled to apply power to rotate the cam 41, so that the volute type line switches to the first type line A with lower semi-anechoic chamber noise.

[0054] In the above steps, it is mentioned that the design of the cam 41 is based on the type line A, B (the first type line A and the second type line B have been determined through testing) and the position of the cam 41 and the fastening piece 3 relative to the ring wall of the volute. The following is an example of any position to illustrate the specific design method. The two ends of the fastening piece 3 are respectively welded and fixed with the cover plate 1, so that it is bent at the end and has a welded positioning mark 31 on the bent part. On the line connecting the center of the welded positioning mark 31 and the center of the cam shaft 411 of the cam 41 at the corresponding position, the distance between the first type line A and the second type line B is L1, the distance between the center of the cam shaft 411 and the outer type line (one of the first type line A and the second type line B is located outside in this case, and the first type line A is shown in the figure) is L2, and the thickness of the ring wall body 223 is b. The base circle radius of the cam 41 is N1, and the distance from the most protruding part of the cam 41 to the center of the cam shaft 411 is N2. The distance from the welded positioning mark 31 to the outer type line is preferably 5-30mm. The position of the hole 32 for connecting the cam shaft 411 on the fastening piece 3 is arranged to avoid interference between the cam shaft 411 and the cover plate 1, and the distance from the hole 32 to the outer type line is preferably 5-20mm. b is preferably 0.5-1mm, which meets the requirements of strength and flexibility.

[0055] After the above design is completed, the above L1, L2 and b are considered as known, wherein N1 should satisfy: N1=L2-b; N2 should satisfy: N2=L1+L2-b.

Claims

1. A volute assembly of a centrifugal fan, comprising two cover plates (1) arranged at intervals, a ring wall is arranged between the two cover plates (1), the ring wall comprises a volute tongue (21); characterized in that: the ring wall further comprises a camber adjusting assembly, the camber adjusting assembly comprises a fixed shaft (221) and a ring wall body (223) capable of being deformed, the fixed shaft (221) is arranged in parallel with the axis of the centrifugal fan and adjacent to the volute tongue (21) in the circumferential direction, the two ends of the fixed shaft (221) are fixed with the cover plates (1) at the corresponding positions respectively, and a part of the ring wall body (223) is wound on the fixed shaft (221) and kept in tension; the volute assembly further comprises a motion mechanism for driving the ring wall body (223) to move to change the camber of the ring wall, the motion mechanism comprises a cam (41) arranged outside the ring wall and capable of rotating relative to the ring wall, the rotation axis of the cam (41) is parallel to the extension direction of the fixed shaft (221), and the ring wall body (223) keeps the tendency of being close to the cam (41). the volute assembly further comprises a fastening sheet (3) arranged outside the ring wall body (223), the fastening sheet (3) is parallel to the extension direction of the fixed shaft (221), the two ends of the fastening sheet (3) are fixed with the cover plates (1) at the corresponding positions respectively, and the cam (41) is arranged on the fastening sheet (3) by a cam shaft (411) for rotation.

2. The volute assembly of a centrifugal fan according to claim 1, characterized in that: the motion mechanism further comprises an elastic member (42) connected between the ring wall body (223) and the fastening sheet (3) to apply an outwardly pulling force to the part of the ring wall body (223) not wound on the fixed shaft (221).

3. The volute assembly of a centrifugal fan according to claim 2, wherein: the ring wall body (223) can at least be in two positions to make the ring wall have a first camber (A) and a second camber (B), the first camber (A) is a camber satisfying the lowest noise of a semi-anechoic chamber, and the second camber (B) is a camber satisfying the lowest working noise; 4. The volute assembly of claim 2, wherein: the end of the fastening sheet (3) is bent and welded with the corresponding cover plate (1), the bent part of the fastening sheet (3) has a welded positioning mark (31), on the line connecting the center of the welded positioning mark (31) and the center of the cam shaft (411) of the corresponding cam (41), the distance between the first camber (A) and the second camber (B) is L1, the distance between the center of the cam shaft (411) and the camber outside is L2, the thickness of the ring wall body (223) is b, the base circle radius of the cam (41) is N1, the distance from the center of the cam shaft (411) to the most protruding part of the cam (41) is N2, and satisfy: N1 = L2 - b; N2 should satisfy: N2 = L1 + L2 - b. on the line connecting the center of the welded positioning mark (31) and the center of the cam shaft (411) of the corresponding cam (41), the distance between the welded positioning mark (31) and the camber outside is 5-30 mm.

5. The volute assembly of a centrifugal fan according to claim 4, wherein: ​ 6. The centrifugal fan volute assembly of claim 4, wherein: A hole (32) for connecting with the cam shaft (411) is arranged on the fastening piece (3), and the distance between the hole (32) and the outer profile is 5-20 mm on the line connecting the center of the welding positioning mark (31) and the center of the cam shaft (411) of the corresponding cam (41).

7. The centrifugal fan volute assembly of claim 4, wherein: The value range of b is 0.5-1 mm.

8. The volute assembly of a centrifugal fan according to any one of claims 1 to 7, characterized in that: The cam (41) has at least two and is uniformly spaced along the circumference of the ring wall.

9. The volute assembly of a centrifugal fan according to any one of claims 1 to 7, characterized in that: The profile adjusting assembly further comprises a clock spring (222), and the end of the ring wall body (223) is connected with the fixed shaft (221) through the clock spring (222), so that the ring wall body (223) is kept in tension by increasing the number of turns around the fixed shaft (221) when moving radially inward.

10. The volute assembly of a centrifugal fan according to any one of claims 1 to 7, characterized in that: The end of the ring wall body (223) away from the fixed shaft (221) is formed with a flange (224), the flange (224) is formed on the opposite sides of the ring wall body (223), one side of each cover plate (1) towards the volute assembly is formed with a limiting groove (11), the limiting groove (11) extends along the width direction of the volute assembly, the flange (224) is clamped into the limiting groove (11) and can move linearly along the limiting groove (11).

11. The volute assembly of the centrifugal fan according to any one of claims 1 to 7, characterized in that: The outer side edge of each cover plate (1) is further formed with a limiting flange (13), each limiting flange (13) is formed by bending the edge of the cover plate (1) towards another cover plate (1).

12. A centrifugal fan characterized by: The volute assembly as claimed in any one of claims 1-11 is applied.

13. A range hood characterized by: The centrifugal fan as claimed in claim 12 is applied.

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